Method for transmitting uplink control information and device using same in wireless communication system

Abstract

Provided are an operation method of a device and a device using the method in a wireless communication system. According to the method, a terminal: receives, from a base station, a plurality of pieces of downlink control information (DCI); receives, from the base station, a plurality of data units scheduled by using the plurality of pieces of DCI; and feeds back, to the base station, pieces of HARQ-ACK information about the plurality of data units, wherein when there is specific DCI missing in a reception process of the plurality of DCIs, additional information related to the specific DCI is transmitted together with the pieces of HARQ-ACK information.

Description

Method for transmitting uplink control information in a wireless communication system and device using the method

[0001] The present disclosure relates to a method for transmitting uplink control information of a device in a wireless communication system and a device using the method.

[0002] As more and more communication devices demand greater communication capacity, the need for improved mobile broadband communications over existing radio access technology (RAT) is emerging. Furthermore, massive Machine Type Communications (MTC), which connects numerous devices and objects to provide diverse services anytime, anywhere, is also a key issue to be considered in next-generation communications. Furthermore, communication system design that considers reliability and latency-sensitive services / terminals is being discussed. The introduction of next-generation radio access technologies that take enhanced mobile broadband communications, massive MTC, and URLLC (Ultra-Reliable and Low Latency Communication) into account is being discussed. For convenience, these technologies are referred to herein as new RAT or NR.

[0003] In a NR or later wireless communication system, a terminal may receive a plurality of downlink scheduling information (e.g., downlink control information (DCI)), receive a plurality of data based on the plurality of downlink scheduling information, and feed back HARQ (hybrid automatic repeat request)-ACK (acknowledgement) information for the data.

[0004] In this process, the NACK transmitted by the terminal may be, i) when scheduling information is received and decoding of scheduled data is attempted but decoding fails, or ii) when the terminal determines that it is a NACK because it did not receive scheduling information.

[0005] In particular, when a terminal feeds back HARQ-ACK information for the plurality of data through a single UCI, it is difficult for the base station to determine which of the above-mentioned cases i) and ii) some NACKs included in the UCI correspond to. Therefore, when performing retransmission in response to a NACK, there may be cases where it is difficult for the base station to determine which data should be retransmitted and in what manner (e.g., which RV (redundancy version) index data should be transmitted, which MCS (modulation and coding scheme) index should be indicated, etc.).

[0006] The technical problem to be solved by the present disclosure is to provide a method for transmitting uplink control information of a device in a wireless communication system and a device using the method.

[0007] A method for transmitting uplink control information in a wireless communication system is provided. According to the method, a terminal receives a plurality of downlink control information (DCI) from a base station, receives a plurality of data units scheduled by the plurality of DCIs from the base station, and feeds back HARQ-ACK information for the plurality of data units to the base station. In addition, if there is a specific DCI that is missed in reception during the reception of the plurality of DCIs, additional information related to the specific DCI is transmitted together with the HARQ-ACK information.

[0008] In another aspect, a terminal for executing the above method, a chipset of the terminal, and a computer-readable medium are provided.

[0009] In another aspect, a method of operating a base station and a base station using the method are provided. According to the method, the base station transmits a plurality of downlink control information (DCI) to a terminal, transmits a plurality of data units scheduled by the plurality of DCIs to the terminal, and receives HARQ-ACK information for the plurality of data units from the terminal. At this time, if there is a specific DCI that is missed during the reception of the plurality of DCIs by the terminal, the base station is characterized in that it receives additional information related to the specific DCI from the terminal together with the HARQ-ACK information.

[0010] According to the method according to the present disclosure, when a terminal receives a plurality of DCIs for scheduling PDSCHs and transmits A / N information for data included in the PDSCHs at once, the base station can distinguish whether NACK information for specific data is i) a NACK that occurs when the terminal receives the DCI and attempts to receive the specific data but fails to decode it, or ii) a NACK that the terminal determines to be the result of not receiving the DCI. Accordingly, when retransmitting data due to missing DCI, the base station can appropriately perform RV index, MCS index indication, etc.

[0011] When retransmitting the above data, it is possible to alleviate / prevent the problem of the terminal still not being able to properly receive the above data.

[0012] Figure 1 illustrates the system architecture of a New Generation Radio Access Network (NG-RAN) to which NR is applied.

[0013] Figure 2 is a block diagram showing a radio protocol architecture for a user plane.

[0014] Figure 3 is a block diagram showing the wireless protocol structure for the control plane.

[0015] Figure 4 illustrates the functional division between NG-RAN and 5GC.

[0016] Figure 5 illustrates a frame structure that can be applied in NR.

[0017] Figure 6 shows an example of a resource grid in NR.

[0018] Figure 7 shows an example of a physical resource block in NR.

[0019] Figure 8 illustrates the slot structure of an NR frame.

[0020] Figure 9 illustrates a core set.

[0021] Figure 10 illustrates an example of a slot structure for a new wireless access technology.

[0022] Figure 11 illustrates the structure of a self-contained slot.

[0023] Figure 12 illustrates physical channels and typical signal transmission.

[0024] Figure 13 illustrates the structure of the basic graph of NR.

[0025] Figure 14 illustrates the output of an interleaver in the case of 16QAM modulation.

[0026] Figure 15 illustrates an example of a flexible network topology to which embodiments of the present specification may be applied.

[0027] Figure 16 illustrates an operation method of the terminal.

[0028] Figure 17 illustrates a signaling process and operation method between a base station and a terminal.

[0029] Figure 18 illustrates a wireless device applicable to the present specification.

[0030] Figure 19 illustrates another example of a wireless device.

[0031] Figure 20 illustrates an example of a signal processing module structure.

[0032] Figure 21 illustrates another example of the structure of a signal processing module within a transmission device.

[0033] FIG. 22 illustrates an example of a wireless communication device according to an implementation example of the present disclosure.

[0034] Fig. 23 illustrates a communication system (1) applicable to this specification.

[0035] As used herein, "A or B" can mean "only A," "only B," or "both A and B." In other words, as used herein, "A or B" can be interpreted as "A and / or B." For example, as used herein, "A, B or C" can mean "only A," "only B," "only C," or "any combination of A, B and C."

[0036] As used herein, a slash ( / ) or a comma can mean "and / or." For example, "A / B" can mean "A and / or B." Accordingly, "A / B" can mean "only A," "only B," or "both A and B." For example, "A, B, C" can mean "A, B, or C."

[0037] In this specification, "at least one of A and B" may mean "only A", "only B" or "both A and B". Additionally, in this specification, the expressions "at least one of A or B" or "at least one of A and / or B" may be interpreted identically to "at least one of A and B".

[0038] Additionally, in this specification, “at least one of A, B and C” can mean “only A,” “only B,” “only C,” or “any combination of A, B and C.” Additionally, “at least one of A, B or C” or “at least one of A, B and / or C” can mean “at least one of A, B and C.”

[0039] Additionally, parentheses used herein may mean "for example." Specifically, when "control information (ABC)" is indicated, "ABC" may be described as an example of "control information." For example, "control information" may include DEF as another example. In other words, "control information" in this specification is not limited to "ABC," and "ABC" may be described as an example of "control information." Furthermore, even when indicated as "control information (i.e., ABC)," "ABC" may be described as an example of "control information."

[0040] Additionally, in this specification, terms such as “first,” “second,” etc. are used only for the purpose of distinguishing one component from another, and are not used to limit the components, and do not limit the order or importance between the components unless specifically limited. Accordingly, a first component in one embodiment of this specification may be referred to as a second component in another embodiment, and similarly, a second component in one embodiment may be referred to as a first component in another embodiment.

[0041] In the following explanation, ‘when, if, in case of’ can be replaced with ‘based on’.

[0042] Technical features individually described within a single drawing in this specification may be implemented individually or simultaneously. The following drawings are designed to illustrate specific examples of this specification. The names of specific devices and the names of specific signals, messages, and fields depicted in the drawings are provided for illustrative purposes only, and therefore, the technical features of this specification are not limited to the specific names used in the drawings.

[0043] In this specification, a terminal is a user equipment (UE) or a consumer-side device, and may also be referred to as a first node that receives / transmits signals from / to a base station / second node / IAB node / TRP (Transmission-Reception Point). A terminal may correspond to a physical node or a logical node. A terminal may correspond to an endpoint on the user side, or may correspond to an intermediate point between other endpoints. In communication between two points that are not limited to endpoints (including one-to-one / many-to-one / one-to-many / many-to-many communication), a terminal may correspond to a served node. A terminal may be a node with a fixed location, or a node with an unfixed location (or mobile).

[0044] In this specification, a base station (BS) is a device on the network side, and may be referred to as a second node / IAB node / x-NodeB (x-NodeB, x may be an abbreviation related to radio access technology (RAT)) / TRP. A BS may correspond to a physical node or a logical node. A BS may correspond to an endpoint on the network side, or may correspond to an intermediate point between other endpoints. In communication between two points that are not limited to endpoints (including one-to-one / many-to-one / one-to-many / many-to-many communication), a BS may correspond to a serving node. A BS may be a node with a fixed location, or a node with an unfixed location.

[0045] In this specification, higher layer parameters may be set for the terminal, preset, or predefined. For example, the base station may transmit higher layer parameters to the terminal. For example, the terminal may transmit parameters such as capabilities to the base station as higher layer parameters. For example, the higher layer parameters may be transmitted via radio resource control (RRC) signaling or medium access control (MAC) signaling.

[0046] In this specification, the information / state / parameter being “configured or pre-configured” can be interpreted as the information / state / parameter being provided / pre-provided to the terminal through pre-defined signaling (e.g., SIB, MAC, RRC) from the base station. In this specification, the information / state / parameter being “defined or pre-defined” can be interpreted as the information / state / parameter being known in advance or pre-stored at the base station and the terminal without signaling between the base station and the terminal.

[0047] The technology described in this specification can be used in various wireless communication systems such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access). CDMA can be implemented with wireless technologies such as UTRA (universal terrestrial radio access) or CDMA2000. TDMA can be implemented with wireless technologies such as GSM (global system for mobile communications) / GPRS (general packet radio service) / EDGE (enhanced data rates for GSM evolution). OFDMA can be implemented with wireless technologies such as IEEE (Institute of Electrical and Electronics Engineers) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, E-UTRA (evolved UTRA), LTE (long term evolution), and 5G NR.

[0048] The technology described in this specification can be implemented with 6G wireless technology and applied to various 6G systems. For example, the 6G system can have key factors such as enhanced mobile broadband (eMBB), ultra-reliable low latency communications (URLLC), massive machine-type communication (mMTC), artificial intelligence (AI) integrated communication, tactile internet, high throughput, high network capacity, high energy efficiency, low backhaul and access network congestion, and enhanced data security.

[0049] Hereinafter, downlink (DL) refers to communication from a base station to a terminal, and uplink (UL) refers to communication from a terminal to a base station. In downlink, a transmitter may be part of a base station, and a receiver may be part of a terminal. In uplink, a transmitter may be part of a terminal, and a receiver may be part of a base station. A base station may be expressed as a first communication device, and a terminal may be expressed as a second communication device. A base station (BS) may be replaced by terms such as a fixed station, Node B, eNB (evolved-NodeB), gNB (Next Generation NodeB), BTS (base transceiver system), access point (AP: Access Point), network (5G network), AI (Artificial Intelligence) system / module, RSU (road side unit), robot, drone (Unmanned Aerial Vehicle, UAV), AR (Augmented Reality) device, VR (Virtual Reality) device, etc.In addition, the terminal may be fixed or mobile, and may be replaced with terms such as UE (User Equipment), MS (Mobile Station), UT (user terminal), MSS (Mobile Subscriber Station), SS (Subscriber Station), AMS (Advanced Mobile Station), WT (Wireless terminal), MTC (Machine-Type Communication) device, M2M (Machine-to-Machine) device, D2D (Device-to-Device) device, vehicle, RSU (road side unit), robot, AI (Artificial Intelligence) module, drone (Unmanned Aerial Vehicle, UAV), AR (Augmented Reality) device, VR (Virtual Reality) device, etc.

[0050] The following technologies can be used in various wireless access systems, such as CDMA, FDMA, TDMA, OFDMA, and SC-FDMA. UTRA is part of UMTS (Universal Mobile Telecommunications System). 3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution) is part of E-UMTS (Evolved UMTS) that uses E-UTRA, and LTE-A (Advanced) / LTE-A pro is an evolved version of 3GPP LTE. 3GPP NR (New Radio or New Radio Access Technology) is an evolved version of 3GPP LTE / LTE-A / LTE-A pro.

[0051] For clarity, the description is based on the 3GPP communication system (e.g., LTE-A, NR), but the technical idea of ​​the present disclosure is not limited thereto. LTE refers to technology after 3GPP TS 36.xxx Release 8. Specifically, LTE technology after 3GPP TS 36.xxx Release 10 is referred to as LTE-A, and LTE technology after 3GPP TS 36.xxx Release 13 is referred to as LTE-A pro. 3GPP NR refers to technology after TS 38.xxx Release 15. LTE / NR may be referred to as a 3GPP system. "xxx" refers to a standard document detail number. LTE / NR may be collectively referred to as a 3GPP system. For background technology, terms, abbreviations, etc. used in the description of the present disclosure, reference may be made to matters described in standard documents published prior to the present disclosure. For example, reference may be made to the following documents:

[0052] 3GPP LTE

[0053] - 36.211: Physical channels and modulation

[0054] - 36.212: Multiplexing and channel coding

[0055] - 36.213: Physical layer procedures

[0056] - 36.300: Overall description

[0057] - 36.331: Radio Resource Control (RRC)

[0058] 3GPP NR

[0059] - 38.211: Physical channels and modulation

[0060] - 38.212: Multiplexing and channel coding

[0061] - 38.213: Physical layer procedures for control

[0062] - 38.214: Physical layer procedures for data

[0063] - 38.300: NR and NG-RAN Overall Description

[0064] - 36.331: Radio Resource Control (RRC) protocol specification

[0065] 이하에서, 아래의 정의 및 약어(Definition and Abbreviations)를 사용할 수 있다.

[0066] BM: beam management

[0067] CQI: channel quality indicator

[0068] CRI: CSI-RS (channel state information - reference signal) resource indicator

[0069] CSI: channel state information

[0070] CSI-IM: channel state information - interference measurement

[0071] CSI-RS: channel state information - reference signal

[0072] DMRS: demodulation reference signal

[0073] FDM: frequency division multiplexing

[0074] FFT: fast Fourier transform

[0075] IFDMA: interleaved frequency division multiple access

[0076] IFFT: inverse fast Fourier transform

[0077] L1-RSRP: Layer 1 reference signal received power

[0078] L1-RSRQ: Layer 1 reference signal received quality

[0079] MAC: medium access control

[0080] MCS: Modulation and coding scheme

[0081] NZP: non-zero power

[0082] OFDM: orthogonal frequency division multiplexing

[0083] PDCCH: physical downlink control channel

[0084] PDSCH: physical downlink shared channel

[0085] PMI: precoding matrix indicator

[0086] PUCCH: Physical uplink control channel

[0087] PUSCH: Physical uplink shared channel

[0088] RE: resource element

[0089] RI: Rank indicator

[0090] RRC: radio resource control

[0091] RSSI: received signal strength indicator

[0092] Rx: Reception

[0093] QCL: quasi co-location

[0094] SINR: signal to interference and noise ratio

[0095] SSB (or SS / PBCH block): synchronization signal block (including primary synchronization signal, secondary synchronization signal and physical broadcast channel)

[0096] TDM: time division multiplexing

[0097] TRP: transmission and reception point

[0098] TRS: tracking reference signal

[0099] Tx: transmission

[0100] UE: user equipment

[0101] ZP: zero power

[0102] As more and more communication devices demand greater communication capacity, the need for improved mobile broadband communication compared to existing radio access technologies is emerging. Furthermore, massive Machine Type Communications (MTC), which connects numerous devices and objects to provide various services anytime, anywhere, is also a key issue to be considered in next-generation communications. Furthermore, communication system design that considers reliability and latency-sensitive services / terminals is being discussed. Accordingly, the introduction of next-generation radio access technologies such as enhanced mobile broadband communication (eMBB), massive MTC (MMTC), and Ultra-Reliable and Low Latency Communication (URLLC) is being discussed, and for convenience, these technologies are referred to as NR in this specification. NR is an expression representing an example of 5G radio access technology (RAT).

[0103] A new RAT system, including NR, uses OFDM transmission scheme or a similar transmission scheme. The new RAT system may follow OFDM parameters different from those of LTE. Alternatively, the new RAT system may follow the existing LTE / LTE-A numerology but have a larger system bandwidth (e.g., 100 MHz). Alternatively, a single cell may support multiple numerologies. For example, terminals operating under different numerologies may coexist within a single cell.

[0104] A numerology corresponds to a single subcarrier spacing in the frequency domain. Different numerologies can be defined by scaling the reference subcarrier spacing by an integer N.

[0105] The three key requirement areas for 5G include (1) Enhanced Mobile Broadband (eMBB), (2) Massive Machine Type Communication (mMTC), and (3) Ultra-reliable and Low Latency Communications (URLLC).

[0106] Some use cases may require optimization across multiple domains, while others may focus on just one Key Performance Indicator (KPI). 5G supports these diverse use cases in a flexible and reliable manner.

[0107] eMBB extends far beyond basic mobile internet access, encompassing rich interactive tasks, cloud computing, and augmented reality media and entertainment applications. Data is a key driver of 5G, and dedicated voice services may not be the first to emerge in the 5G era. In 5G, voice is expected to be handled as an application, simply using the data connection provided by the communication system. The primary drivers of increased traffic volume are the increasing size of content and the growing number of applications requiring high data rates. Streaming services (audio and video), interactive video, and mobile internet connectivity will become more prevalent as more devices connect to the internet. Many of these applications require always-on connectivity to push real-time information and notifications to users. Cloud storage and applications are rapidly growing on mobile communication platforms, applicable to both work and entertainment. Cloud storage is a particular use case driving the growth of uplink data rates. 5G is also used for remote work in the cloud, requiring significantly lower end-to-end latency to maintain a superior user experience when tactile interfaces are used. Entertainment, for example, cloud gaming and video streaming are other key factors driving the demand for mobile broadband. Entertainment is essential on smartphones and tablets, regardless of location, including in highly mobile environments such as trains, cars, and airplanes. Another use case is augmented reality and information retrieval for entertainment, where augmented reality requires extremely low latency and instantaneous data volumes.

[0108] Additionally, one of the most anticipated 5G use cases involves the ability to seamlessly connect embedded sensors across all sectors, such as mMTC. The number of potential IoT devices is projected to reach 20.4 billion by 2020. Industrial IoT is one area where 5G will play a key role, enabling smart cities, asset tracking, smart utilities, agriculture, and security infrastructure.

[0109] URLLC encompasses new services that will transform industries through ultra-reliable, low-latency links, such as remote control of critical infrastructure and self-driving vehicles. Reliability and latency are essential for smart grid control, industrial automation, robotics, and drone control and coordination.

[0110] Let's take a more specific look at several use cases.

[0111] 5G can complement fiber-to-the-home (FTTH) and cable-based broadband (or DOCSIS) by delivering streams rated at hundreds of megabits per second to gigabits per second. These high speeds are required to deliver TV at resolutions beyond 4K (6K, 8K, and beyond), as well as virtual and augmented reality. Virtual reality (VR) and augmented reality (AR) applications include near-immersive sports events. Certain applications may require specialized network configurations. For example, for VR games, game companies may need to integrate their core servers with the network operator's edge network servers to minimize latency.

[0112] Automotive is expected to be a significant new driver for 5G, with numerous use cases for in-vehicle mobile communications. Passenger entertainment, for example, demands simultaneous high-capacity and high-mobility mobile broadband. This is because future users will expect high-quality connectivity regardless of their location or speed. Another automotive application is an augmented reality dashboard, which overlays information on what the driver sees through the windshield, identifying objects in the dark and informing the driver about their distance and movement. In the future, wireless modules will enable communication between vehicles, the exchange of information between vehicles and supporting infrastructure, and between vehicles and other connected devices (e.g., devices accompanying pedestrians). Safety systems can guide drivers on alternative courses of action to ensure safer driving, reducing the risk of accidents. The next step will be remotely controlled or self-driving vehicles, which will require highly reliable and fast communication between different self-driving vehicles and between vehicles and infrastructure. In the future, self-driving cars will perform all driving tasks, leaving drivers to focus solely on traffic anomalies that the vehicles themselves cannot detect. The technological requirements for self-driving cars will require ultra-low latency and ultra-high-speed reliability, increasing traffic safety to levels unattainable by humans.

[0113] Smart cities and smart homes, often referred to as "smart societies," will be embedded with dense wireless sensor networks. A distributed network of intelligent sensors will identify conditions for cost- and energy-efficient maintenance of cities or homes. A similar setup can be implemented for each home. Temperature sensors, window and heating controllers, burglar alarms, and appliances will all be connected wirelessly. Many of these sensors typically have low data rates, low power, and low cost. However, for example, real-time HD video may be required for certain types of devices for surveillance purposes.

[0114] The consumption and distribution of energy, including heat and gas, are becoming increasingly decentralized, requiring automated control of distributed sensor networks. Smart grids interconnect these sensors using digital information and communication technologies to collect and act on information. This information can include the behavior of suppliers and consumers, enabling smart grids to improve efficiency, reliability, economic efficiency, sustainable production, and automated distribution of fuels like electricity. Smart grids can also be viewed as another low-latency sensor network.

[0115] The health sector has numerous applications that can benefit from mobile communications. Telecommunications systems can support telemedicine, which provides clinical care in remote locations. This can help reduce distance barriers and improve access to health services that are otherwise unavailable in remote rural areas. It can also be used to save lives in critical care and emergency situations. Mobile-based wireless sensor networks can provide remote monitoring and sensors for parameters such as heart rate and blood pressure.

[0116] Wireless and mobile communications are becoming increasingly important in industrial applications. Wiring is expensive to install and maintain. Therefore, the potential to replace cables with reconfigurable wireless links presents an attractive opportunity for many industries. However, achieving this requires wireless connections to operate with similar latency, reliability, and capacity to cables, while simplifying their management. Low latency and extremely low error rates are new requirements for 5G connectivity.

[0117] Logistics and freight tracking are important use cases for mobile communications, enabling the tracking of inventory and packages anywhere using location-based information systems. Logistics and freight tracking typically require low data rates but wide coverage and reliable location information.

[0118] Multi-Input Multi-Output (MIMO) technology in NR systems provides a scalable and flexible MIMO framework. Basically, it includes beam-based operation, scalable and flexible Channel State Information (CSI) codebook, reference signal (RS) design, and codebook design for CSI Type I and CSI Type II. Additionally, improvements have been introduced to support a CSI Type II codebook for multi-user (MU)-MIMO, multiple transmit / receive points (TRPs) or multiple panel transmission operations depending on backhaul conditions, multi-beam operation, high uplink transmit power support, and reference signals with low Peak-to-Average Power Ratio (PAPR) characteristics. Furthermore, beam management methods to reduce beam failure for wireless devices moving at high frequencies, expansion of multi-TRP transmission in uplink and downlink, sounding reference signals (SRSs) for capacity and coverage expansion, and improvements to Type II CSI-RSs can be supported.

[0119] Describes a conventional wireless communication system. This may also be called an Evolved-UMTS Terrestrial Radio Access Network (E-UTRAN) or a Long Term Evolution (LTE) / LTE-A system.

[0120] E-UTRAN includes a base station (BS), which provides a control plane and a user plane to user equipment (UE). A UE may be fixed or mobile, and may be referred to by other terms such as a mobile station (MS), a user terminal (UT), a subscriber station (SS), a mobile terminal (MT), a wireless device, or a terminal. A base station (BS) is a fixed point that communicates with a UE, and may be referred to by other terms such as an evolved-NodeB (eNB), a gNodeB (gNB), a base transceiver system (BTS), or an access point.

[0121] Base stations can be interconnected via the X2 interface. Base stations are connected to the Evolved Packet Core (EPC) via the S1 interface, more specifically, to the Mobility Management Entity (MME) via the S1-MME, and to the Serving Gateway (S-GW) via the S1-U.

[0122] The EPC consists of an MME, an S-GW, and a P-GW (Packet Data Network Gateway). The MME holds information about terminal access and capabilities, and this information is primarily used for terminal mobility management. The S-GW is a gateway that terminates on the E-UTRAN, and the P-GW is a gateway that terminates on the PDN.

[0123] Figure 1 illustrates the system architecture of a New Generation Radio Access Network (NG-RAN) to which NR is applied.

[0124] Referring to Fig. 1, the NG-RAN may include gNBs and / or eNBs that provide user plane and control plane protocol termination to the UE. Fig. 1 exemplifies a case including only gNBs. The gNBs (eNBs) are connected to each other via Xn interfaces. The gNBs and eNBs are connected to the 5th generation core network (5G Core Network: 5GC) via the NG interface. More specifically, they are connected to the access and mobility management function (AMF) via the NG-C interface, and to the user plane function (UPF) via the NG-U interface.

[0125] The layers of the radio interface protocol between the terminal and the network can be divided into L1 (layer 1), L2 (layer 2), and L3 (layer 3) based on the three lower layers of the Open System Interconnection (OSI) standard model, which is widely known in communication systems. Among these, the physical layer belonging to layer 1 provides information transfer service using physical channels, and the RRC (Radio Resource Control) layer located in layer 3 controls radio resources between the terminal and the network. To this end, the RRC layer exchanges RRC messages between the terminal and the base station.

[0126] Figure 2 is a block diagram illustrating the radio protocol architecture for the user plane. Figure 3 is a block diagram illustrating the radio protocol architecture for the control plane. The user plane is a protocol stack for transmitting user data, and the control plane is a protocol stack for transmitting control signals.

[0127] Referring to Figures 2 and 3, the physical layer (PHY layer) provides information transfer services to upper layers using physical channels. The PHY layer is connected to its upper layer, the Medium Access Control (MAC) layer, through a transport channel. Data is transferred between the MAC layer and the PHY layer via the transport channel. Transport channels are classified based on how and with what characteristics data is transmitted over the wireless interface.

[0128] Data travels between different physical layers, i.e., between the physical layers of a transmitter and receiver, via a physical channel. This physical channel can be modulated using Orthogonal Frequency Division Multiplexing (OFDM) and utilizes time and frequency as radio resources.

[0129] The MAC layer's functions include mapping between logical channels and transport channels, and multiplexing / demultiplexing MAC service data units (SDUs) belonging to logical channels into transport blocks provided as physical channels on the transport channels. The MAC layer provides services to the RLC (Radio Link Control) layer through logical channels.

[0130] The functions of the RLC layer include concatenation, segmentation, and reassembly of RLC SDUs. To guarantee the various Quality of Service (QoS) required by radio bearers (RBs), the RLC layer provides three operating modes: Transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged Mode (AM). AM RLC provides error correction through automatic repeat request (ARQ).

[0131] The RRC (Radio Resource Control) layer is defined only in the control plane. The RRC layer is responsible for controlling logical, transport, and physical channels, including the configuration, reconfiguration, and release of radio bearers. An RB is a logical path provided by Layer 1 (PHY layer) and Layer 2 (MAC layer, RLC layer, PDCP layer) for data transmission between a terminal and the network.

[0132] The functions of the Packet Data Convergence Protocol (PDCP) layer in the user plane include the transmission of user data, header compression, and ciphering. The functions of the Packet Data Convergence Protocol (PDCP) layer in the control plane include the transmission of control plane data and encryption / integrity protection.

[0133] Establishing an RB refers to the process of defining the characteristics of the radio protocol layer and channel to provide a specific service, and setting specific parameters and operating methods for each. RBs can be further divided into two types: signaling RBs (SRBs) and data RBs (DRBs). SRBs are used as a conduit for transmitting RRC messages in the control plane, while DRBs are used as conduits for transmitting user data in the user plane.

[0134] When an RRC connection is established between the RRC layer of the terminal and the RRC layer of the E-UTRAN, the terminal is in an RRC connected state, otherwise it is in an RRC idle state.

[0135] Downlink transmission channels that transmit data from the network to the terminal include the Broadcast Channel (BCH), which transmits system information, and the downlink Shared Channel (SCH), which transmits user traffic or control messages. Traffic or control messages for downlink multicast or broadcast services may be transmitted through the downlink SCH or a separate downlink Multicast Channel (MCH). Meanwhile, uplink transmission channels that transmit data from the terminal to the network include the Random Access Channel (RACH), which transmits initial control messages, and the uplink Shared Channel (SCH), which transmits user traffic or control messages.

[0136] Logical channels that are located above the transport channel and are mapped to the transport channel include BCCH (Broadcast Control Channel), PCCH (Paging Control Channel), CCCH (Common Control Channel), MCCH (Multicast Control Channel), and MTCH (Multicast Traffic Channel).

[0137] A physical channel consists of multiple OFDM symbols in the time domain and multiple subcarriers in the frequency domain. A single subframe consists of multiple OFDM symbols in the time domain. A resource block is a resource allocation unit and consists of multiple OFDM symbols and multiple subcarriers. Additionally, each subframe can use specific subcarriers of specific OFDM symbols (e.g., the first OFDM symbol) of the subframe for the Physical Downlink Control Channel (PDCCH), for example, the L1 / L2 control channel. A Transmission Time Interval (TTI) is a unit time for subframe transmission.

[0138] Figure 4 illustrates the functional division between NG-RAN and 5GC.

[0139] Referring to FIG. 4, the gNB can provide functions such as inter-cell radio resource management (Inter Cell RRM), radio bearer management (RB control), connection mobility control (Connection Mobility Control), radio admission control (Radio Admission Control), measurement configuration and provision, and dynamic resource allocation. The AMF can provide functions such as NAS security and idle state mobility processing. The UPF can provide functions such as mobility anchoring and PDU processing. The SMF (Session Management Function) can provide functions such as terminal IP address allocation and PDU session control.

[0140] Figure 5 illustrates a frame structure that can be applied in NR.

[0141] Referring to FIG. 5, a radio frame (hereinafter abbreviated as a frame) can be used for uplink and downlink transmission in NR. A frame has a length of 10 ms and can be defined as two 5 ms half-frames (Half-Frames, HF). A half-frame can be defined as five 1 ms sub-frames (Subframes, SF). A frame can include 10 sub-frames. A sub-frame can be divided into one or more slots, and the number of slots in a sub-frame depends on the Subcarrier Spacing (SCS). Each slot includes 12 or 14 OFDM (A) symbols depending on the cyclic prefix (CP). When a normal CP is used, each slot includes 14 symbols. When an extended CP is used, each slot includes 12 symbols. Here, the symbol may include an OFDM symbol (or CP-OFDM symbol), an SC-FDMA symbol (or a DFT-s-OFDM symbol). A mini-slot may include, for example, 2, 4, or 7 symbols, or may include more or fewer symbols.

[0142] NR systems can support multiple numerologies. Numerologies can be defined by subcarrier spacing and cyclic prefix (CP) overhead. Multiple subcarrier spacings can be derived by scaling the basic subcarrier spacing by an integer N. Furthermore, even if it is assumed that very low subcarrier spacing is not utilized at very high carrier frequencies, the numerologies utilized can be selected independently of the frequency band. Furthermore, NR systems can support various frame structures corresponding to multiple numerologies.

[0143] Below, we examine the Orthogonal Frequency Division Multiplexing (OFDM) numerologies and frame structures that can be considered in NR systems. Table 1 lists the various OFDM numerologies supported in NR systems.

[0144] Table 1 below illustrates the subcarrier spacing configuration μ (also referred to as subcarrier spacing configuration).

[0145] [Table 1]

[0146]

[0147] Regarding the frame structure in the NR system, the sizes of the various fields in the time domain are T s =1 / (Δf max ·N f ) can be expressed as a multiple of the time unit. Here, Δf max =480·10 3 and N f =409. Downlink and uplink transmissions are T f =(Δf max ·N f / 100)·T s = It consists of a radio frame with a duration of 10ms. Here, each radio frame is T sf =(Δf max ·N f / 1000)·T s = It consists of 10 subframes with a duration of 1ms. In this case, there may be one set of frames for uplink and one set of frames for downlink. In addition, the transmission of uplink frame number i from a terminal (User Equipment, UE) is T earlier than the start of the corresponding downlink frame from the terminal. TA =N TA ·T sIt must start before. For numerology μ, slots are n within a subframe. μ s ∈{0, ..., N slots,μ subframe -1} are numbered in increasing order, and n within a radio frame μ s,f ∈{0, ..., N slots,μ frame -1} are numbered in increasing order. One slot is N μ symb It consists of consecutive OFDM symbols, and N μ symb is determined by the numerology and slot configuration used. Slot n in a subframe μ s The start of OFDM symbol n in the same subframe μ s N μ symb are aligned temporally with the start of the OFDM signal. Not all terminals can transmit and receive simultaneously, which means that not all OFDM symbols in a downlink slot or uplink slot can be utilized.

[0148] Table 2 below shows the number of slots (N) in a frame according to the subcarrier spacing setting μ. frame,μ slot ), number of slots in a subframe (N subframe,μ slot ), number of symbols in the slot (N slot symb ) are examples.

[0149] [Table 2]

[0150]

[0151] Table 2-1 below illustrates that when extended CP is used, the number of symbols per slot, the number of slots per frame, and the number of slots per subframe change depending on the SCS.

[0152] [Table 2-1]

[0153]

[0154] In an NR system, OFDM(A) numerologies (e.g., SCS, CP length, etc.) may be set differently between multiple cells that are merged into a single terminal. Accordingly, the (absolute time) interval of a time resource (e.g., SF, slot, or TTI) (conveniently referred to as TU (Time Unit)) consisting of the same number of symbols may be set differently between the merged cells.

[0155] In relation to physical resources in an NR system, antenna ports, resource grids, resource elements, resource blocks, and carrier parts can be considered. Hereinafter, the physical resources that can be considered in an NR system will be described in detail. First, with respect to antenna ports, an antenna port is defined such that the channel through which a symbol on the antenna port is carried can be inferred from the channel through which another symbol on the same antenna port is carried. If the large-scale properties of the channel through which a symbol on one antenna port is carried can be inferred from the channel through which a symbol on another antenna port is carried, then the two antenna ports can be said to be in a QC / QCL (quasi co-located or quasi co-location) relationship. Here, the large-scale properties include one or more of delay spread, Doppler spread, frequency shift, average received power, and received timing.

[0156] Figure 6 shows an example of a resource grid in NR.

[0157] Referring to Figure 6, the resource grid is N in the frequency domain. μ RB N RB sc It consists of subcarriers, and one subframe is 14·2 μ It is described as an example, but not limited to, that it consists of OFDM symbols. In an NR system, the transmitted signal is N μ RB N RB sc One or more resource grids consisting of subcarriers and 2 μ N (μ) symb is described by OFDM symbols. Here, N μ RB≤ N max,μ RB is. The above N max,μ RB represents the maximum transmission bandwidth, which may vary between numerologies as well as between uplink and downlink. In this case, one resource grid may be configured for each numerology μ and each antenna port p. Each element of the resource grid for numerology μ and each antenna port p is referred to as a resource element and is uniquely identified by an index pair {index in the frequency domain, position of the symbol within the subframe}. If there is no risk of confusion or if a particular antenna port or numerology is not specified, the indices p and μ may be dropped. In addition, a resource block (RB) is defined as N in the frequency domain. RB sc =12 is defined as a series of consecutive subcarriers.

[0158] Point A serves as a common reference point of the resource block grid and is obtained as follows.

[0159] offsetToPointA for primary cell (Pcell) downlink represents the frequency offset between the lowest subcarrier of the lowest resource block overlapping the SS / PBCH block used by the terminal for initial cell selection and point A, expressed in resource block units assuming 15 kHz subcarrier spacing for FR1 and 60 kHz subcarrier spacing for FR2, and absoluteFrequencyPointA represents the frequency-location of point A expressed as in absolute radio-frequency channel number (ARFCN).

[0160] Common resource blocks (CRBs) are numbered from 0 upwards in the frequency domain for a subcarrier spacing setting μ. The center of subcarrier 0 of CRB 0 for a subcarrier spacing setting μ coincides with 'point A'. CRB number n in the frequency domain μ CRB The resource elements (k,l) for the subcarrier spacing setting μ are given by the following equation.

[0161] [Formula 1]

[0162]

[0163] k is defined relative to point A so that k=0 corresponds to the subcarrier centered at point A. Physical resource blocks are numbered from 0 to N within the bandwidth part (BWP). size BWP,i - Numbered from 1 to 1, where i is the number of BWP. Physical resource block n in BWP i PRB and common resource block n CRBThe relationship between them is given by the equation below.

[0164] [Formula 2]

[0165]

[0166] N start BWP,i is a common resource block where BWP starts relative to common resource block 0.

[0167] Figure 7 shows an example of a physical resource block in NR.

[0168] Referring to FIG. 7, a physical resource block (PRB) may be composed of different frequency resources and time resources depending on the subcarrier spacing.

[0169] Figure 8 illustrates the slot structure of an NR frame.

[0170] Referring to FIG. 8, a slot may include multiple symbols in the time domain. For example, in the case of a normal CP, one slot may include 14 symbols, but in the case of an extended CP, one slot may include 12 symbols. A carrier may include multiple subcarriers in the frequency domain. A Resource Block (RB) may be defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A Bandwidth Part (BWP) may be defined as multiple consecutive (P)RBs in the frequency domain, and may correspond to a single numerology (e.g., SCS, CP length, etc.). A carrier may include up to N BWPs (e.g., 4 or 5). Data communication is performed through activated BWPs, and only one BWP may be activated for one terminal. In the resource grid, each element is referred to as a Resource Element (RE), to which one complex symbol can be mapped.

[0171] As another example, in the time domain, a slot for a normal CP contains 7 symbols, but in the case of an extended CP, a slot contains 6 symbols. A carrier contains multiple subcarriers in the frequency domain. A Resource Block (RB) is defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A Bandwidth Part (BWP) is defined as multiple consecutive (P)RBs in the frequency domain, and can correspond to a single numerology (e.g., SCS, CP length, etc.). A carrier can contain up to N (e.g., 5) BWPs. Data communication is performed through activated BWPs, and only one BWP can be activated for a single terminal. Each element in the resource grid is referred to as a Resource Element (RE), to which one complex symbol can be mapped.

[0172] A PDCCH (physical downlink control channel) may be composed of one or more CCEs (control channel elements) as shown in Table 3 below.

[0173] [Table 3]

[0174]

[0175] For example, a PDCCH can be transmitted via a resource consisting of 1, 2, 4, 8, or 16 CCEs, where a CCE is composed of 6 resource element groups (REGs), and one REG is composed of one resource block in the frequency domain and one orthogonal frequency division multiplexing (OFDM) symbol in the time domain.

[0176] Monitoring refers to decoding each PDCCH candidate according to the DCI (downlink control information) format. The terminal monitors a set of PDCCH candidates in one or more core sets (CORESETs, described below) on the active DL BWP of each activated serving cell for which PDCCH monitoring is configured, according to the corresponding search space set.

[0177] In NR, a new unit called a control resource set (CORESET) can be introduced. A terminal can receive PDCCHs in a CORESET.

[0178] Figure 9 illustrates a core set.

[0179] Referring to Figure 9, the core set is N in the frequency domain. CORESET RB It consists of N resource blocks and is in the time domain. CORESET symb ∈ {1, 2, 3} symbols. N CORESET RB , N CORESET symb can be provided by the base station via upper layer signals. As illustrated in Fig. 9, a core set may include multiple CCEs (or REGs).

[0180] Within a core set, a terminal can attempt PDCCH detection in units of 1, 2, 4, 8, or 16 CCEs. One or more CCEs for which PDCCH detection can be attempted can be referred to as PDCCH candidates. A terminal can be configured with multiple core sets.

[0181] In conventional wireless communication systems (e.g., LTE / LTE-A), the control domain spans the entire system bandwidth used by the base station. Except for some terminals that support only narrow bandwidths (e.g., eMTC / NB-IoT terminals), all terminals must be able to receive radio signals across the entire system bandwidth of the base station to properly receive / decode the control information transmitted by the base station.

[0182] In contrast, NR introduces the aforementioned core set. A core set is a radio resource for control information that a terminal must receive. It can utilize only a portion of the system bandwidth in the frequency domain, rather than the entire bandwidth. Furthermore, it can utilize only a portion of the symbols within a slot in the time domain. The base station can assign a core set to each terminal and transmit control information through the assigned core set. In NR, a terminal can receive control information from the base station without necessarily receiving the entire system bandwidth.

[0183] The core set may include a terminal-specific core set for transmitting terminal-specific control information and a common core set for transmitting control information common to all terminals.

[0184] Meanwhile, in NR, depending on the application field, high reliability may be required, and in such a situation, the target block error rate (BLER) for downlink control information (DCI) transmitted through a downlink control channel (e.g., physical downlink control channel: PDCCH) may be significantly lower than in the prior art. One example of a method for satisfying such a requirement requiring high reliability is to reduce the amount of content included in the DCI and / or increase the amount of resources used when transmitting the DCI. In this case, the resources may include at least one of time domain resources, frequency domain resources, code domain resources, and spatial domain resources.

[0185] The following technologies / features can be applied in NR:

[0186] Self-contained subframe structure

[0187] Figure 10 illustrates an example of a slot structure for a new wireless access technology.

[0188] In NR, a structure in which a control channel and a data channel are time-division multiplexed (TDM) within one TTI, as shown in Fig. 10, can be considered for the purpose of minimizing latency.

[0189] FIG. 10 illustrates an example in which a downlink control region is located at the front of the TTI and an uplink control region is located at the back of the TTI. The region between the downlink control region and the uplink control region can be used for downlink data (DL data) transmission or uplink data (UL data) transmission. A characteristic of this structure is that downlink (DL) reception and uplink (UL) transmission are sequentially performed within a single subframe / slot, so that DL data can be received and UL ACK / NACK (Acknowledgement / Not-acknowledgement) can be transmitted within a single subframe / slot. As a result, the time required for data retransmission when a data transmission error occurs is reduced, thereby minimizing the latency of the final data transmission.

[0190] In this way, in a structure where data and control domains are TDMed, a time gap is required for the base station and terminal to transition from transmission mode to reception mode, or from reception mode to transmission mode. To this end, some OFDM symbols at the transition point from DL to UL in a self-contained subframe structure can be designated as a guard period (GP).

[0191] Figure 11 illustrates the structure of a self-contained slot.

[0192] In an NR system, a single slot may contain a DL control channel, DL or UL data, and a UL control channel. For example, the first N symbols in a slot may be used to transmit a DL control channel (hereinafter, referred to as a DL control region), and the last M symbols in the slot may be used to transmit a UL control channel (hereinafter, referred to as a UL control region). N and M are each integers greater than or equal to 0. A resource region (hereinafter, referred to as a data region) between the DL control region and the UL control region may be used for DL ​​data transmission or UL data transmission. As an example, the following configuration may be considered. Each section is listed in chronological order.

[0193] 1. DL only configuration

[0194] 2. UL only configuration

[0195] 3. Mixed UL-DL configuration

[0196] - DL area + GP (Guard Period) + UL control area

[0197] - DL control area + GP + UL area

[0198] DL area: (i) DL data area, (ii) DL control area + DL data area

[0199] UL domain: (i) UL data domain, (ii) UL data domain + UL control domain

[0200] In the DL control region, a PDCCH can be transmitted, and in the DL data region, a PDSCH (physical downlink shared channel) can be transmitted. In the UL control region, a PUCCH (physical uplink control channel) can be transmitted, and in the UL data region, a PUSCH (physical uplink shared channel) can be transmitted. In the PDCCH, downlink control information (DCI), such as DL data scheduling information and UL data scheduling information, can be transmitted. In the PUCCH, uplink control information (UCI), such as ACK / NACK (Positive Acknowledgement / Negative Acknowledgement) information for DL ​​data, CSI (Channel State Information) information, and SR (Scheduling Request), can be transmitted. GP provides a time gap when a base station and a terminal switch from transmission mode to reception mode or from reception mode to transmission mode. Some symbols at the time of switching from DL to UL within a subframe can be set as GP.

[0201] System information of an NR system can be transmitted in a broadcasting manner. At this time, analog beams belonging to different antenna panels within one symbol can be transmitted simultaneously, and a method of introducing a beam reference signal (BRS), which is a reference signal (RS) transmitted by applying a single analog beam (corresponding to a specific antenna panel) to measure a channel for each analog beam, is being discussed. The BRS can be defined for multiple antenna ports, and each antenna port of the BRS can correspond to a single analog beam. At this time, unlike the BRS, a synchronization signal or xPBCH can be transmitted by applying all analog beams within an analog beam group so that any terminal can receive it well.

[0202] In NR, a synchronization signal block (SSB, or may be referred to as a synchronization signal and physical broadcast channel (SS / PBCH) in the time domain) may be composed of four OFDM symbols numbered in ascending order from 0 to 3 within the synchronization signal block, and a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a PBCH associated with a demodulation reference signal (DMRS) may be mapped to the symbols. As described above, the synchronization signal block may also be referred to as an SS / PBCH block.

[0203] In NR, multiple synchronization signal blocks can be transmitted at different times, and SSB can be used to perform initial access (IA), serving cell measurement, etc. Therefore, when the transmission time and resources overlap with other signals, it is desirable to transmit SSB preferentially. To achieve this, the network can broadcast SSB transmission time and resource information or indicate it through UE-specific RRC signaling.

[0204] NR can perform beam-based transmission and reception operations. If the reception performance of the current serving beam degrades, a process called beam failure recovery (BFR) can be used to find a new beam.

[0205] Since BFR is not a process for declaring an error / failure in the link between the network and the terminal, it can be assumed that the connection with the current serving cell is maintained even when the BFR process is performed. During the BFR process, measurements are performed on different beams set by the network (a beam can be expressed as a CSI-RS port or an SSB (synchronization signal block) index, etc.) and the best beam for the terminal is selected. The terminal can proceed with the BFR process by performing the RACH process associated with the beam with the best measurement result.

[0206] Now, we will describe the Transmission Configuration Indicator (TCI) state. The TCI state can be set for each core set of the control channel, and parameters for determining the terminal's receive (Rx) beam can be determined based on the TCI state.

[0207] For each downlink bandwidth portion (DL BWP) of a serving cell, a terminal may be configured with up to three core sets. Additionally, for each core set, the terminal may be provided with the following information:

[0208] 1) Coreset index p (e.g., one from 0 to 11, where the index of each coreset can be uniquely determined among the BWPs of a serving cell),

[0209] 2) PDCCH DM-RS scrambling sequence initialization value,

[0210] 3) Interval in the time domain of the core set (can be given in symbol units),

[0211] 4) A set of resource blocks,

[0212] 5) CCE-to-REG mapping parameters,

[0213] 6) Antenna port quasi co-location (QCL) information indicating quasi co-location (QCL) information of DM-RS antenna ports for PDCCH reception in each core set (from a set of antenna port quasi co-locations provided by a higher layer parameter called 'TCI-State');

[0214] 7) Indicating the presence or absence of a transmission configuration indication (TCI) field for a specific DCI format transmitted by PDCCH in the core set, etc.

[0215] Let's explain QCL. If the characteristics of the channel through which a symbol on one antenna port is transmitted can be inferred from the characteristics of the channel through which a symbol on another antenna port is transmitted, then the two antenna ports are said to be in quasi-co-location (QCL). For example, if two signals (A and B) are transmitted from the same transmit antenna array with identical / similar spatial filters applied, the two signals may experience identical / similar channel conditions. From the receiver's perspective, if one of the two signals is received, the channel characteristics of the received signal can be used to detect the other signal.

[0216] In this sense, the fact that A and B are QCL may mean that A and B experienced similar channel conditions, and thus, the channel information estimated to detect A is also useful for detecting B. Here, the channel conditions may be defined by, for example, Doppler shift, Doppler spread, average delay, delay spread, spatial reception parameters, etc.

[0217] The 'TCI-State' parameter associates one or two downlink reference signals with a corresponding QCL type (there are QCL types A, B, C, and D, see Table 4).

[0218] [Table 4]

[0219]

[0220] Each 'TCI-State' may include parameters for establishing a quasi-colocation (QCL) relationship between one or two downlink reference signals and a DM-RS port of a PDSCH (or PDCCH), or a CSI-RS port of a CSI-RS resource.

[0221] Meanwhile, in each DL BWP configured for a terminal in a serving cell, the terminal may be provided with up to 10 search space sets. For each search space set, the terminal may be provided with at least one of the following pieces of information:

[0222] 1) Search space set index s (0≤s<40), 2) Association between core set P and search space set s, 3) PDCCH monitoring period and PDCCH monitoring offset (slot unit), 4) PDCCH monitoring pattern within a slot (e.g., indicating the first symbol of the core set within a slot for PDCCH monitoring), 5) Number of slots in which search space set s exists, 6) Number of PDCCH candidates per CCE aggregation level, 7) Information indicating whether search space set s is CSS (common search space) or USS (UE-specific search space), etc.

[0223] In NR, core set #0 can be configured by PBCH (or terminal-specific signaling for handover, PSCell configuration, or BWP configuration). The search space (SS) set #0 configured by PBCH can have different monitoring offsets (e.g., slot offset, symbol offset) for each associated SSB. This may be necessary to minimize the search space occasions that the terminal must monitor. Alternatively, it may also be necessary to provide a beam sweeping control / data area that can transmit control / data for each beam so that communication with the terminal can be continuously performed in a situation where the best beam of the terminal dynamically changes.

[0224] Figure 12 illustrates physical channels and typical signal transmission.

[0225] Referring to Figure 12, in a wireless communication system, a terminal receives information from a base station via the downlink (DL), and the terminal transmits information to the base station via the uplink (UL). The information transmitted and received between the base station and the terminal includes data and various control information, and various physical channels exist depending on the type and purpose of the information they transmit and receive.

[0226] When a terminal is powered on again from a powered-off state or newly enters a cell, it performs an initial cell search operation, such as synchronizing with the base station (S11). To this end, the terminal receives the PSCH (Primary Synchronization Channel) and SSCH (Secondary Synchronization Channel) from the base station to synchronize with the base station and obtain information such as the cell ID (cell identity). In addition, the terminal can obtain broadcast information within the cell by receiving the PBCH (Physical Broadcast Channel) from the base station. In addition, the terminal can receive the DL RS (Downlink Reference Signal) during the initial cell search phase to check the downlink channel status.

[0227] (Initial) cell search can be defined as a procedure in which a terminal acquires time and frequency synchronization with a cell and detects the cell ID of the cell. Cell search can be based on the primary synchronization signal and secondary synchronization signal of the cell, and the PBCH DMRS.

[0228] A terminal that has completed initial cell search can obtain more specific system information by receiving a PDCCH (Physical Downlink Control Channel) and a corresponding PDSCH (Physical Downlink Control Channel) (S12).

[0229] Thereafter, the terminal can perform a random access procedure (Random Access Procedure) to complete connection to the base station (S13-S16). Specifically, the terminal can transmit a preamble through a Physical Random Access Channel (PRACH) (S13) and receive a Random Access Response (RAR) for the preamble through a PDCCH and a corresponding PDSCH (S14). Thereafter, the terminal can transmit a Physical Uplink Shared Channel (PUSCH) using scheduling information in the RAR (S15) and perform a contention resolution procedure (Contention Resolution Procedure) such as a PDCCH and a corresponding PDSCH (which can be considered a process of receiving a contention resolution message) (S16).

[0230] When accessing a base station for the first time or when there is no radio resource for signal transmission, a terminal may perform a random access procedure (RACH) for the base station. At this time, a 4-step contention-based or type-1 random access may include a first step in which the terminal transmits a random access preamble (or Msg1) to the base station, a second step in which the terminal receives a random access response (RAR) (or Msg2) from the base station, a third step in which the terminal transmits an uplink message (or Msg3) to the base station, and a fourth step in which the terminal receives a contention resolution message (or Msg4) from the base station. Alternatively, a 2-step contention-based or type-2 random access may include a step A in which the terminal transmits a random access preamble and an uplink message to the base station, and a step B in which the terminal receives a random access response and a contention resolution message from the base station. A contention-free random access procedure may only include steps 1 and 2 of a contention-based access procedure, and steps 3 and 4 are not required because no contention occurs between terminals.

[0231] The terminal can transmit a random access preamble or PRACH to the base station based on the random access opportunity (RO), preamble transmission power, etc. provided through SIB1 or dedicated RRC signaling. Here, the terminal can select an optimal SSB or CSI-RS (Channel Status Information-Reference Signal) and determine an RO and / or preamble index group associated with the selected SSB or CSI-RS. The terminal can select an optimal SSB and a corresponding reception beam from among a plurality of SSBs corresponding to the multi-beam sweeping of the base station during the initial access process. Meanwhile, after the initial access, the terminal can perform transmission beam and / or reception beam selection or change through a CSI measurement and reporting process based on the CSI-RS from the base station in an RRC connection state.

[0232] After the terminal transmits the preamble, the terminal can monitor RAR reception for a predetermined period of time. For example, the terminal can monitor the PDCCH scrambled with RA-RNTI and receive the RAR through the PDSCH transmitted in the resource scheduled by the DCI in the PDCCH. The RAR may include a Random Access Preamble Identifier (RAPID), an uplink grant (UL Grant) for Msg3 scheduling, a temporary cell identifier (Temporary C(Cell)-RNTI), and a Timing Advance Command (TAC) determined based on the preamble reception timing.

[0233] If the terminal fails to successfully receive the RAR, the preamble can be retransmitted by applying power ramping, etc.

[0234] If the terminal successfully receives the RAR, it can transmit Msg3 based on the UL grant within the RAR. Once Msg3 is transmitted, the terminal can start the contention resolution timer (CR timer) and perform PDCCH monitoring based on the C-RNTI for Msg4 reception. If Msg4 is received while the CR timer is running, the terminal can determine that contention resolution has been successfully completed.

[0235] A terminal that has performed the above-described procedure can then perform PDCCH / PDSCH reception (S17) and PUSCH / PUCCH (Physical Uplink Control Channel) transmission (S18) as general uplink / downlink signal transmission procedures. Control information that the terminal transmits to the base station is referred to as UCI (Uplink Control Information). UCI includes HARQ ACK / NACK (Hybrid Automatic Repeat and reQuest Acknowledgement / Negative-ACK), SR (Scheduling Request), CSI (Channel State Information), etc. CSI includes CQI (Channel Quality Indicator), PMI (Precoding Matrix Indicator), RI (Rank Indication), etc. UCI is generally transmitted through PUCCH, but can be transmitted through PUSCH when control information and data must be transmitted simultaneously. In addition, the terminal can aperiodically transmit UCI through PUSCH according to a request / instruction of the network. UCI can be repeatedly transmitted over PUCCH.

[0236] Meanwhile, the control information that the terminal transmits to the base station via the uplink (or that the terminal receives from the base station) may include downlink / uplink ACK / NACK signals, CQI (Channel Quality Indicator), PMI (Precoding Matrix Index), RI (Rank Indicator), etc. For example, in the case of a 3GPP LTE system, the terminal may transmit the above-described control information such as CQI / PMI / RI via PUSCH and / or PUCCH.

[0237] The table below shows an example of the DCI format.

[0238] [Table 5]

[0239]

[0240] Referring to Table 5 above, DCI formats 0_0, 0_1, and 0_2 may include resource information related to scheduling of PUSCH (e.g., UL / SUL (Supplementary UL), frequency resource allocation, time resource allocation, frequency hopping, etc.), transport block (TB) related information (e.g., MCS, NDI, RV, etc.), HARQ related information (e.g., process number, downlink assignment index (DAI), PDSCH-HARQ feedback timing, etc.), multi-antenna related information (e.g., DMRS sequence initialization information, antenna port, CSI request, etc.), power control information (e.g., PUSCH power control, etc.), and the control information included in each DCI format may be predefined.

[0241] DCI format 0_0 is used for scheduling PUSCH in a single cell. The information contained in DCI format 0_0 is CRC-scrambled and transmitted using C-RNTI, CS-RNTI, or MCS-C-RNTI.

[0242] DCI format 0_1 ​​is used to schedule one or more PUSCHs in a single cell, or to indicate configured grant (CG) downlink feedback information to the UE. The information contained in DCI format 0_1 ​​is CRC-scrambled and transmitted using the C-RNTI, CS-RNTI, SP-CSI-RNTI, or MCS-C-RNTI.

[0243] DCI format 0_2 is used for scheduling PUSCH in a single cell. The information contained in DCI format 0_2 is CRC-scrambled and transmitted using C-RNTI, CS-RNTI, SP-CSI-RNTI, or MCS-C-RNTI.

[0244] Next, DCI formats 1_0, 1_1, and 1_2 may include resource information related to scheduling of PDSCH (e.g., frequency resource allocation, time resource allocation, VRB-PRB mapping, etc.), transport block (TB) related information (e.g., MCS, NDI, RV, etc.), HARQ related information (e.g., process number, DAI, PDSCH-HARQ feedback timing, etc.), multi-antenna related information (e.g., antenna port, TCI, SRS request, etc.), PUCCH related information (e.g., PUCCH power control, PUCCH resource indicator, etc.), and control information included in each DCI format may be predefined.

[0245] DCI format 1_0 is used for scheduling PDSCH in a DL cell. The information contained in DCI format 1_0 is CRC-scrambled and transmitted using C-RNTI, CS-RNTI, or MCS-C-RNTI.

[0246] DCI format 1_1 is used for scheduling PDSCH in a single cell. Information included in DCI format 1_1 is CRC-scrambled and transmitted using C-RNTI, CS-RNTI, or MCS-C-RNTI.

[0247] DCI format 1_2 is used for scheduling PDSCH in a single cell. The information contained in DCI format 1_2 is CRC-scrambled and transmitted using C-RNTI, CS-RNTI, or MCS-C-RNTI.

[0248] DCI format 1_3 is used to schedule a single PDSCH in a single cell or multiple PDSCHs in multiple cells with one PDSCH per cell. The information contained in DCI format 1_3 is transmitted CRC-scrambled by C-RNTI or MCS-C-RNTI.

[0249] <LDPC(Low Density Parity Check) 코드>

[0250] A key component of the 5G NR standard is the use of advanced error correction codes, such as LDPC codes, to ensure reliable transmission over wireless channels. 5G must support high throughputs of up to 20 Gbps, various block sizes with different code rates on the data channel, and Hybrid Automatic Repeat Request (HARQ).

[0251] LDPC codes offer a good solution that meets all the requirements set by 3GPP. The base graph of 5G NR LDPC codes is structured, and the parity check matrix can efficiently support HARQ and rate compatibility. This base graph characteristic allows it to support an arbitrary number of transmitted information bits at various code rates over a wide range.

[0252] <Base Graphs of 5G NR LDPC Codes>

[0253] Figure 13 illustrates the structure of the basic graph of NR.

[0254] Referring to Figure 13, two types of base graphs (BGs), BG-1 and BG-2, can be defined. The use of these BGs can be determined based on the size of the required information bits and the code transmission rate. For example, BG-1 consists of 46 rows and 68 columns, and the size of the information block is K = 22Z. c , BG-2 consists of 42 rows and 52 columns, and K = 10Z c It can be. Here, Z c is the size of the lifting matrix, and Table 6 below illustrates a set of lifting sizes defined for 5G NR.

[0255] [Table 6]

[0256]

[0257] The block structure of BG-1 and BG-2 is identical. Columns include Information Columns, Core Parity Columns, and Extension Parity Columns. Rows are divided into Core Check Rows and Extension Check Rows.

[0258] [Table 7]

[0259]

[0260] Submatrix E is a dual diagonal matrix useful for low-complexity encoding of LDPC. Each basic graph has 51 lifting sizes, ranging from 2 to 384.

[0261] According to the LDPC encoding procedure, 66Z c Generate coded bits (for BG-1) and 50Z cGenerates coded bits (for BG-2). The coded bits in BG-1 and BG-2 are output in the order of systematic bits, core parity bits, and extended parity bits.

[0262] <NR LDPC 코드에서 레이트 매칭(Rate Matching in NR LDPC Codes)>

[0263] The N coded bits generated according to the LDPC encoding procedure are subjected to a rate matching process that selects G coded bits to match the size and modulation order of the resources allocated to transmission of the transport block. The coded bits generated for the rate matching process are stored in a circular buffer, and the initial bit locations of the coded bits to be transmitted are selected based on the redundancy version (RV) index of HARQ.

[0264] [Table 8]

[0265]

[0266] <NR LDPC 코드에서 인터리빙(Interleaving in NR LDPC Codes)>

[0267] In higher-order QAM modulation schemes such as 16QAM (order 4) or higher, the transmission reliability of each bit in the n-bit tuple that determines the QAM symbol varies depending on the bit position. Gray mapping is typically applied so that the most significant bit (MSB) has higher reliability than the least significant bit (LSB).

[0268] Figure 14 illustrates the output of an interleaver in the case of 16QAM modulation.

[0269] Referring to Fig. 14, the LDPC codeword code bits are written row by row from row 1, and the output of the block interleaver is read column by column from the left column and transmitted after 16QAM modulation. Therefore, the code bits mapped to rows 1&2 are located in the MSB of the 4-bit tuple that determines the 16QAM symbol, and are transmitted more reliably in the QAM symbol of Gray mapping. This operation allows the systematic bits with higher priority among the LDPC code bits to be transmitted more reliably.

[0270] <NR에서 레이어 맵핑(Layer mapping in NR)>

[0271] In MIMO 2 codeword transmission, each layer is divided into two sets, and data is transmitted with independent MCSs for each set. For example, a separate TB is allocated for each layer set, and each is channel-encoded to transmit an independent codeword for each layer set.

[0272] The table below shows the codeword-to-layer mapping relationship. A single codeword is transmitted for ranks below 4. In this case, modulation symbols are mapped alternately across each layer to maximize diversity gains.

[0273] [Table 9]

[0274]

[0275] <NR에서 변조 맵퍼(modulation mapper)>

[0276] In QPSK modulation, pairs of bits, b(2i), b(2i+1), are mapped to complex-valued modulation symbols d(i) as follows:

[0277] [Formula 3]

[0278]

[0279] In 16QAM modulation, 4 bits, b(4i), b(4i+1), b(4i+2), b(4i+3), are mapped to complex value modulation symbols d(i) as shown below.

[0280] [Formula 4]

[0281]

[0282] In 64QAM modulation, 6 bits, b(6i), b(6i+1), b(6i+2), b(6i+3), b(6i+4), b(6i+5), are mapped to complex value modulation symbols d(i) as shown below.

[0283] [Formula 5]

[0284]

[0285] Here, even-numbered input bits are mapped to the I-channel (in phase channel), and odd-numbered input bits are mapped to the Q-channel (quadrature channel).

[0286] In 16QAM modulation, b(4i) and b(4i+1) are transmitted more reliably than b(4i+2) and b(4i+3) in the I-channel and Q-channel, respectively.

[0287] To enable reasonable battery consumption when BA (bandwidth adaptation) is configured, only one uplink BWP and one downlink BWP, or only one downlink / uplink BWP pair, for each uplink carrier can be activated at a time within an active serving cell, while all other BWPs configured in the UE are deactivated. In deactivated BWPs, the UE does not monitor the PDCCH and does not transmit on the PUCCH, PRACH, and UL-SCH.

[0288] For BA, the receive and transmit bandwidth of the terminal need not be as wide as the cell bandwidth and can be adjusted: the width can be commanded to change (e.g., shrinking during periods of low activity to save power), the location in the frequency domain can be moved (e.g., to increase scheduling flexibility), and the subcarrier spacing can be commanded to change (e.g., to allow different services). A subset of the total cell bandwidth of a cell is referred to as a bandwidth part (BWP), and a BA is obtained by setting BWP(s) to the terminal and notifying the terminal which of the set BWPs is currently active. Once a BA is set, the terminal only needs to monitor the PDCCH on one active BWP. For example, there is no need to monitor the PDCCH on the entire downlink frequency of the cell. A BWP inactive timer (independent of the DRX inactive timer described above) is used to switch an active BWP to a default BWP: the timer is restarted upon successful PDCCH decoding, and a switch to the default BWP occurs when the timer expires.

[0289] Below, we describe the integrated access and backhaul link (IAB). For convenience, the proposed approach is based on the new RAT (NR) system. However, the scope of the proposed approach can be expanded to include other systems, such as 3GPP LTE / LTE-A systems, in addition to NR systems.

[0290] One potential technology that aims to enable future cellular network deployment scenarios and applications is support for wireless backhaul and relay links, enabling flexible and very dense deployment of NR cells without the need to proportionally densify the transport network.

[0291] The expected availability of greater bandwidth in NR compared to LTE (e.g., in the mmWave spectrum), along with the native deployment of massive MIMO or multi-beam systems, creates opportunities for the development and deployment of integrated access and backhaul links. This allows for easier deployment of dense networks of self-backhauled NR cells in a more integrated manner by establishing multiple control and data channels / procedures defined to provide connectivity or access to terminals. Such systems are referred to as integrated access and backhaul links (IAB).

[0292] In this disclosure, the following are defined:

[0293] - AC(x): Access link between node(x) and terminal(s).

[0294] - BH(xy): Backhaul link between node(x) and node(y).

[0295] At this time, the node may refer to a DgNB (donor gNB) or a relay node (RN). Here, the DgNB or donor node may be a gNB that provides a function to support backhaul for IAB nodes.

[0296] When relay node 1 and relay node 2 exist, and relay node 1 is connected to relay node 2 via a backhaul link and relays data transmitted and received to relay node 2, relay node 1 is called the parent node of relay node 2, and relay node 2 is called the child node of relay node 1.

[0297] 6G Network Structure

[0298] Figure 15 illustrates an example of a flexible network topology to which embodiments of the present specification may be applied.

[0299] Referring to Figure 15, a network topology in which a split radio access network (RAN) is configured more flexibly and resiliently can be considered to compensate for incomplete areas of network coverage.

[0300] For this purpose, various nodes such as IAB nodes, relays, and RF repeaters as in the example of Fig. 15 may be applied, and NTN (non-terrestrial network) may be integrated.

[0301] For example, an IAB node may correspond to a node providing wireless backhaul. For example, a relay may refer to any intermediate point, or in the case of a sidelink relay where a terminal functions as a relay, it may collectively refer to a terminal-to-network (U2N) relay and a terminal-to-terminal (U2U) relay.

[0302] For example, an RF repeater may be a node that simply performs the function of signal amplification and forwarding, or, in the case of a network-controlled repeater (NCR), it may not only amplify and forward signals, but also adjust its transmit and receive settings based on information provided by the network.

[0303] For example, NTN nodes could be satellites or aircraft that provide NTN coverage that terrestrial networks struggle to provide. Beyond these examples, various intermediate points can be introduced to improve the network topology.

[0304] In Figure 15, a split RAN can support partitioning a base station into a centralized unit (CU) and one or more distributed units (DUs). The CU and DU can correspond to logical units. The CU can be further partitioned into a control plane (CP) portion and one or more user plane (UP) portions. Since a failure in the CU-CP affects not only the CU-UP but also the DUs, various intermediate points can be introduced to compensate for this.

[0305] An intermediate point may correspond to a terminal or a base station, depending on its relationship to other nodes. For example, an IAB node may include a mobile-termination (MT) portion and a unit (DU). The MT may connect the IAB node to a donor node. The unit (DU) of an IAB node may serve other terminals or connect to other IAB nodes to provide multi-hop wireless backhaul to the terminal. In other words, an IAB node may correspond to a base station in its relationship to a user-side node, and to a terminal in its relationship to a network-side node.

[0306] Hereinafter, in some examples, the description of a terminal can be equally applied not only to a user-side end point, but also to an intermediate point corresponding to a terminal in a relative relationship with a network-side end point. Similarly, in some examples of this specification, the description of a base station can be equally applied not only to a network-side end point, but also to an intermediate point corresponding to a base station in a relative relationship with a user-side end point. However, in most cases where there is no additional description of the operations of three or more entities, the communication entities in this specification can be briefly described as terminals and / or base stations (or first nodes and / or second nodes). Here, the terms terminal and / or base stations (or first nodes and / or second nodes) can be interpreted to include / replace any end point or any intermediate point depending on the relationship with other nodes.

[0307] In some examples of the present specification below, for the sake of simplicity, the subjects of the operations may be referred to as base stations and / or terminals (or first nodes and / or second nodes). In addition, the terms base stations and / or terminals (or first nodes and / or second nodes) may also be interpreted / replaced as in the following examples: For example, the base stations (or first nodes) and terminals (or second nodes) may respectively correspond to the first endpoint and the second endpoint; may respectively correspond to the endpoint and the intermediate point; may respectively correspond to the intermediate point and the endpoint; or may respectively correspond to the first intermediate point and the second intermediate point.

[0308] In this specification, there may be zero or more intermediate points between the base station and the terminal. If intermediate points exist, they may be IAB nodes, relays, RF repeaters, NTN (non-terrestrial network) nodes, or nodes supporting other functions. An intermediate point may be a node with a fixed location or a node with an unfixed location.

[0309] When a terminal feeds back HARQ-ACK information for multiple data through a single UCI, it is difficult for the base station to determine whether some NACKs included in the UCI are i) due to a case where the terminal attempted to decode the scheduled data by receiving scheduling information but failed to decode, or ii) due to the terminal not receiving the scheduling information and determining it as a NACK. Therefore, when performing retransmission in response to a NACK, it may be difficult for the base station to determine which data should be retransmitted and in what manner (e.g., which RV (redundancy version) index of data should be transmitted, which MCS (modulation and coding scheme) index should be indicated, etc.). This problem and its solution are described below. Hereinafter, HARQ-ACK may include ACK (acknowledgement) information or NACK (negative acknowledgment) information, and in this sense may be expressed as ACK / NACK or A / N.

[0310] <A. 기지국이 단말의 DCI 미싱(missing)과 디코딩 실패를 구분하는 것의 필요성>

[0311] 1. RV decision

[0312] When using an LDPC code as a channel code and using the IR-HARQ method for transmitting downlink (DL) information through a PDSCH, systematic bits among the coded bits using RV0 are generally transmitted in the initial transmission, and RV1, RV2, and RV3 are applied in the retransmission to transmit the remaining parity bits.

[0313] If the terminal fails to receive information in the initial transmission, the additional coded bits transmitted in the retransmission are used together with the previously received coded bits to perform decoding. If the terminal misses the DCI scheduling the initial transmission and only receives the retransmission using RV2, the decoding is attempted using only the parity bits corresponding to RV2 among the coded bits. In this case, the terminal may succeed in decoding the information, but performance may be degraded compared to when decoding is performed using the coded bits corresponding to RV0, which primarily transmits systematic bits.

[0314] When transmitting DL information via PDSCH, polar codes are applied as channel codes and the IR-HARQ scheme is applied, different portions of the coded bits may be transmitted during initial transmission and retransmission. In this case, if a terminal misses the initial transmission and only receives the coded bits from the retransmission, decoding the information may be impossible or its performance may be significantly reduced, unlike with LDPC codes.

[0315] At this time, if the base station can determine whether the terminal is missing DCI, the base station can operate differently depending on whether the terminal is missing DCI, as in the following example.

[0316] 1) If the terminal does not miss the DCI scheduling the initial transmission but fails to decode, the base station can expect to improve the decoding performance of the terminal using IR-HARQ by performing retransmission using a different RV.

[0317] 2) If the terminal misses the DCI scheduling the initial transmission, the base station can retransmit the data using the same RV as the initial transmission. This prevents degradation of decoding performance by ensuring that the terminal receives only the portion of the encoded bits essential for decoding.

[0318] 2. Determine TB size

[0319] When scheduling retransmission of DL information via PDSCH, the base station may use the applied MCS value (e.g., I MCS ) can be directly instructed so that the terminal can determine the TB size even when retransmitting. In this case, even if the terminal does not receive the DCI scheduling the initial transmission, the TB size to be applied when retransmitting can be determined.

[0320] Meanwhile, the base station provides MCS values ​​(e.g., I MCS ) through the modulation order (Q) m ) and target code rate (R) directly, instead of specifying the modulation order (Q m ) indicating only the MCS value (e.g., I MCS ) can be directed.

[0321] For example, I of 29, 30, and 31 in Table 10 below MCS The value does not indicate the target code rate but the modulation order (Q m ) only. If such a value is indicated, the terminal determines that the TB size determined through the previously indicated DCI information for scheduling the same information is also applied to the corresponding transmission.

[0322] At this time, the base station transmits DL information through PDSCH using the MCS value (e.g., I MCS ) through the modulation order (Q) m ) and target code rate (R) and the DCI that the terminal schedules the initial transmission was missed, and the base station retransmits the modulation order (Q). m ) If the MCS value is indicated only for the transmission, a problem may occur in which the terminal cannot determine the TB size applied to the transmission.

[0323] [Table 10]

[0324]

[0325] 3. Determining polar code-related information

[0326] When a polar code is applied for transmission of DL information via PDSCH, some information that determines the encoder of the polar code may be determined based on the amount of coded bits transmitted at the time of initial transmission (e.g., the amount of coded bits transmitted after obtaining coded bits through an encoding process of information bits and then going through a rate-matching process based on the amount of resources available for actual transmission).

[0327] For example, in the case of polar code applied for data transmission considering IR-HARQ, N*2 is obtained by extending the base polar code of length N. E A polar code of length N can be used. In this case, the length N of the base polar code can be determined based on the number of coded bits transmitted during the initial transmission.

[0328] In this case, if the terminal misses the DCI scheduling the initial transmission, it may not be able to determine the length N of the base polar code when retransmitting, as it may not be able to determine the amount of coded bits transmitted during the initial transmission.

[0329] <B. 기지국이 단말의 DCI 미싱과 디코딩 실패를 구분하지 못하는 상황>

[0330] To prevent problems such as the above A, it may be necessary for the base station to be able to determine whether the terminal is missing DCI.

[0331] If the base station transmits a DCI for scheduling a PDSCH to a terminal but A / N information for the PDSCH is not received, the base station can determine that 1) the terminal is missing the DCI for scheduling the PDSCH, or 2) the terminal transmitted A / N information but the base station did not properly receive it.

[0332] Meanwhile, when a terminal receives multiple DCIs for scheduling PDSCHs and transmits A / N information for them at once (via the same PUSCH or PUCCH resource), the terminal transmits multiple A / N information for the PDSCHs scheduled through the multiple DCIs to the base station at once, by transport block (TB) or by code block group (CBG) unit for transmitting the A / N information. When the terminal transmits multiple A / N information pieces to the base station, the location where the related A / N information is mapped is determined for each transport block (TB) or by code block group (CBG) for transmitting the A / N information. The location of this A / N information remains unchanged even if the terminal misses some DCIs for scheduling some PDSCHs.

[0333] If the terminal misses the DCI and fails to receive the PDSCH, the terminal processes the A / N information corresponding to the TB / CBG transmitted through the PDSCH as NACK and transmits it.

[0334] In such cases, the base station may receive NACK information for a specific TB / CBG, but may not be able to distinguish whether the NACK information is 1) a NACK that occurred when the terminal received DCI and attempted to receive the TB / CBG but failed to decode it, or 2) a NACK that was determined to be a NACK because the DCI was not received.

[0335] In order to prevent the problem in the above-mentioned 'Section A' from occurring because the base station cannot determine whether the NACK information transmitted by the terminal is due to DCI missing or decoding failure as in the above-mentioned 'Section B', the present disclosure proposes a method in which the terminal feeds back related information to the base station together with A / N information when feeding back information so that the base station can distinguish between DCI missing and decoding failure of the terminal.

[0336] In order to prevent the occurrence of a problem like that in 'Section A' of 'Section 4' above, where the base station cannot determine whether the NACK information transmitted by the terminal is due to DCI missing or decoding failure, as in 'Section B' of 'Section 4' above, the present disclosure proposes a method in which the terminal feeds back related information to the base station together with A / N information when feeding back information so that the base station can distinguish between DCI missing and decoding failure of the terminal.

[0337] Hereinafter, DCI missing information may be information indicating that the terminal failed to receive a specific DCI. However, this is not a limitation. In other words, DCI missing information may also be information related to requesting retransmission of specific data based on the terminal's failure to receive a specific DCI.

[0338] In relation to the operation of the terminal feeding back DCI missing information to the base station, the following factors need to be considered.

[0339] 1) DCI missing of terminal is generally 10 -2It occurs rarely with a probability of . Therefore, it is desirable to minimize the overhead for the terminal to indicate DCI missing information together with A / N feedback.

[0340] 2) The problem that occurs when the base station cannot distinguish between NACK occurrence due to decoding failure and NACK occurrence due to DCI missing mainly occurs in the case of initial transmission or transmission for RV0.

[0341] 3) For A / N information for TB / CBGs scheduled through a specific DCI, if at least one of the A / N information is ACK, none of the NACK information included in the A / N information is NACK caused by missing DCI. In other words, the base station can determine that the terminal has successfully received the DCI, and there is no ambiguity problem regarding NACK occurrence due to decoding failure and NACK occurrence due to missing DCI.

[0342] Considering the above factors, the following proposes a method for notifying whether the NACK information included in the A / N information transmitted by the terminal to the base station is due to DCI missing.

[0343] Hereinafter, for convenience of explanation, information that distinguishes whether the NACK information transmitted by the terminal is due to DCI missing or decoding failure may be referred to as 'DCI missing information' or 'DTX information'.

[0344] <Section 5.1 Feedback Method for DCI Missing Information>

[0345] When a terminal feeds back A / N information for TB / CBG scheduled from multiple DCIs to a base station through the same UCI, a DCI index needs to be defined to distinguish the multiple DCIs.

[0346] At this time, the terminal can determine the DCI index of each DCI according to the mapping order of DAI information or A / N information in the HARQ-ACK codebook as follows.

[0347] 1) The terminal may determine the DAI as a DCI index. In this case, DAI may mean a counter DAI. If both the DAI for A / N feedback in CBG units and the DAI for A / N feedback in TB units exist, the terminal may first determine the DCI index in the order of the DAI for A / N feedback in CBG units, and then determine the DCI index in the order of the DAI for A / N feedback in TB units. Alternatively, if both the DAI for A / N feedback in CBG units and the DAI for A / N feedback in TB units exist, the terminal may first determine the DCI index in the order of the DAI for A / N feedback in TB units, and then determine the DCI index in the order of the DAI for A / N feedback in CBG units.

[0348] 2) The terminal can determine the DCI index based on the order of the A / N information fed back through the HARQ-ACK codebook. When A / N information for TBs / CBGs scheduled by multiple DCIs is fed back, the DCI that schedules the A / N information(s) located further forward in the HARQ-ACK codebook can have a smaller DCI index.

[0349] For example, multiple A / N information fed back by a terminal can be grouped by A / Ns for TB / CBG scheduled by the same DCI. In this case, when the A / N group for the A / N information(s) located earlier in the HARQ-ACK codebook has a lower A / N group index, the DCI that schedules the A / N information(s) belonging to the nth A / N group can have the nth DCI index.

[0350] Alternatively, the terminal may determine the DCI index of each DCI based on predefined rules. For example, the DCI index of each DCI may be determined based on all or part of the following rules.

[0351] 1) A DCI transmitted through a search space that occurs later in time may have a larger DCI index. That is, for multiple DCIs, the later the time resource (e.g., slot or symbol) in which the search space where the terminal received the DCI is located, the greater the DCI index may be determined to be.

[0352] 2) A larger DCI index can be determined as the index of the carrier (cell) through which the DCI is transmitted increases. In other words, for multiple DCIs, the DCI index can be determined to increase as the index of the carrier through which the DCI is transmitted increases.

[0353] 3) A larger DCI index can be determined as the index of the search space in which the DCI is transmitted increases. In other words, for multiple DCIs, the DCI index can be determined to increase as the index of the search space in which the terminal receives the DCI increases.

[0354] 4) A DCI transmitted using a larger PDCCH candidate index within the same search space may have a larger DCI index. That is, for multiple DCIs transmitted through the same search space, the DCI index may be determined to increase as the PDCCH candidate index through which the terminal receives the DCI increases.

[0355] Method 1. DCI missing feedback in DCI units

[0356] When a terminal feeds back A / N information for TBs / CBGs scheduled by multiple DCIs to a base station through the same UCI, NACK information included in TBs / CBGs scheduled by the same DCI may have the same DCI missing information. That is, all NACK information included in TBs / CBGs scheduled by the same DCI may be caused by either the same decoding failure or the same DCI missing.

[0357] Therefore, in the present disclosure, when a terminal feeds back A / N information for TB / CBGs scheduled by multiple DCIs to a base station through the same UCI, the terminal can feed back missing information for each DCI to the base station on a DCI basis. That is, it is proposed that the terminal feed back DCI missing information for A / Ns for TB / CBGs scheduled by the same DCI to the base station on a per-DCI basis.

[0358] The terminal feeds back DCI missing information to the base station in units of DCIs scheduling PDSCH or in units of A / Ns for TBs / CBGs scheduled by the same DCI.

[0359] [Table 11]

[0360]

[0361] Table 11 shows an example of feeding back DCI missing information in DCI units.

[0362] As shown in Table 11, a total of 12 TBs can be scheduled, with 2 TBs per DCI, through a total of 6 DCIs from DCI 0 to 5. At this time, each TB can be composed of 4 CBGs. In this case, the terminal feeds back a total of 48 A / N information to the base station on a CBG basis. In this case, the terminal feeds back missing information of the DCI on a per-DCI basis. In other words, DCI missing information is fed back on a per-DCI basis, with A / N information for CBGs scheduled by the same DCI as a unit.

[0363] (1) Method 1-1.

[0364] When a terminal feeds back A / N information for PDSCHs scheduled by multiple DCIs to a base station, an index can be defined for each DCI that schedules the PDSCHs, and information on whether the terminal has missed the DCI can be fed back on a DCI basis.

[0365] In other words, when a terminal feeds back A / N information for PDSCHs scheduled by multiple DCIs to a base station, the terminal can group A / Ns for TB / CBGs scheduled by the same DCI, define an index for each A / N group, and feed back DCI missing information of NACK(s) included in the A / N group by A / N group unit.

[0366] For example, in Table 11 above, the DCI index is defined for each DCI that schedules the PDSCH. In other words, for example, in Table 11, A / Ns for TBs / CBGs scheduled by the same DCI are grouped, and the A / N group indices of the A / Ns are indicated for each A / N group. Hereinafter, the DCI index may also mean the A / N group index.

[0367] The terminal can feed back DCI missing information to the base station in DCI units as follows.

[0368] Example 1-1-a: Bitmap

[0369] The terminal can feed back DCI missing information by DCI index in bitmap format. The number of DCIs is N. D When we say dog, the terminal is N D - Feedback of DCI missing information for each DCI index is provided through bitmap information composed of bits. For example, if a specific bit value corresponding to DCI index n in the bitmap is 0, it means that the terminal has successfully received the DCI corresponding to the DCI index, and if the bit value is 1, it may mean that the terminal has not received the DCI corresponding to the DCI index.

[0370] As shown in Table 11 above, when the terminal feeds back A / N information for PDSCHs scheduled by DCI 0 to DCI 5 through the same UCI, for example, the terminal may not receive DCI 2 but may successfully receive the remaining DCIs. In this case, when the indices of DCI 0, 1, 2, 3, 4, and 5 are defined as DCI indices 0, 1, 2, 3, 4, and 5 in that order, the terminal may feed back DCI missing information in the form of a bitmap consisting of 6 bits, such as 001000.

[0371] Example 1-1-b: DCI Index

[0372] The terminal can feed back the DCI index value of the DCI where DCI missing occurred.

[0373] More specifically, DCI missing information can be fed back as follows:

[0374] If no DCI missing occurs for all DCIs, the terminal feeds back a value corresponding to a state indicating that no DCI missing occurs.

[0375] When a DCI missing occurs for one DCI corresponding to DCI index n, the terminal feeds back a value corresponding to a status indicating that a DCI missing occurred for DCI index n.

[0376] If DCI missing occurs for two or more DCIs, the terminal feeds back a value corresponding to a status indicating that DCI missing occurred for two or more DCIs.

[0377] Alternatively, you can feedback DCI missing information as follows:

[0378] The number of DCIs is N D When a dog is detected, the terminal feeds back the index value of the DCI where DCI missing occurred.

[0379] A specific index value (e.g., N) D ) may indicate that no DCI missing has occurred for all DCIs. If no DCI missing has occurred for all DCIs, the terminal may set an index value (e.g., N) indicating that no DCI missing has occurred. D ) provides feedback.

[0380] A specific index value (e.g., N) D +1) may indicate that DCI missing has occurred for two or more DCIs. If DCI missing has occurred for two or more DCIs, the terminal may use an index value (e.g., N) indicating that DCI missing has occurred for two or more DCIs. D +1) Feedback.

[0381] For example, if the terminal feeds back A / N information for PDSCHs scheduled by DCI 0 to DCI 5 through the same UCI as in Table 11, the terminal may not receive DCI 2 but may successfully receive the remaining DCIs. In this case, when the indices of DCI 0, 1, 2, 3, 4, and 5 are defined as DCI indices 0, 1, 2, 3, 4, and 5, respectively, the terminal may feed back a value indicating that DCI missing has occurred in DCI index 2 to the base station in order to feed back DCI missing information.

[0382] (2) Method 1-2

[0383] When a terminal feeds back A / N information for PDSCHs scheduled by multiple DCIs to a base station, the terminal can group the DCIs scheduling the corresponding PDSCHs into multiple groups, define an index for each DCI group, and feed back information on whether the terminal has missed the DCI(s) included in the corresponding DCI group by DCI group.

[0384] In other words, when a terminal feeds back A / N information for PDSCHs scheduled by multiple DCIs to a base station, the terminal groups the DCIs into multiple group(s), groups the A / Ns for TB / CBGs scheduled by DCI(s) belonging to the same DCI group, defines an index for each A / N group, and feeds back DCI missing information of NACK(s) included in the corresponding A / N group in units of A / N group indexes.

[0385] [Table 12]

[0386]

[0387] Table 12 shows an example of feeding back DCI missing information by DCI group (A / N group) index unit.

[0388] In Table 12, DCI group indices are defined for each of the multiple DCIs that schedule the PDSCH. In other words, in Table 12, A / Ns for TB / CBGs scheduled by multiple DCIs are grouped, and the A / N group indices of the corresponding A / Ns are displayed for each A / N group. For example, in Table 12, DCI 0 and DCI 1 are grouped with DCI group index 0, DCI 2 and DCI 3 are grouped with DCI group index 1, and DCI 4 and DCI 5 are grouped with DCI group index 2.

[0389] DCIs scheduling PDSCHs are N D When a dog exists, N D The DCIs of the dog are N G Can be grouped into groups of dogs.

[0390] Number of DCI groups N G The dog can be determined as follows:

[0391] Alt 1. Terminal is N G The value can be set from the base station through signaling such as RRC and MAC-CE.

[0392] Alt 2. Terminal is N G The value of 'N D It can be determined that x α' is the same. At this time, α can have a value less than or equal to 1. At this time, the terminal can receive the value of α or a value corresponding to 1 / α from the base station through signaling such as RRC or MAC-CE. Alternatively, the value of α can be fixed to a specific value and defined in the standard specification.

[0393] Alt 3. Terminal is N G The value of can always be judged to be equal to 1.

[0394] Alt 4. Terminal is N G The value of is always N D It can be judged to be the same as .

[0395] At this time, the terminal applies a method such as Alt 1 or Alt 2, but receives N from the base station. G Alternatively, if the α value is not indicated, the method of Alt 3 or Alt 4 can be applied.

[0396] Each DCI group has ceil(N D / N G ) or floor(N D / N G ) may contain DCIs.

[0397] Hereinafter, DCI group index may mean A / N group index.

[0398] The terminal can feed back DCI missing information to the base station in units of DCI group indexes as follows.

[0399] Example 1-2-a: Bitmap.

[0400] The terminal can feed back DCI missing information by DCI group index in bitmap format. That is, the index information of the DCI group that includes the DCI where the DCI missing occurred can be fed back in bitmap format. The number of DCI groups is N. G When we say dog, the terminal is N G - Feedback of DCI missing information for DCIs included in each DCI group index is provided through bitmap information composed of bits. For example, if a specific bit value corresponding to DCI group index n in the bitmap is 0, this means that the terminal has successfully received all DCIs included in DCI group n, and if the bit value is 1, this may mean that the terminal has not received at least one DCI among the DCIs included in DCI group n.

[0401] For example, if the terminal feeds back A / N information for PDSCHs scheduled by DCI 0 to DCI 5 through the same UCI as in Table 12 above, the terminal may not receive DCI 2 but may successfully receive the remaining DCIs. In this case, when three DCI groups are formed by grouping two DCIs each, and the DCI group formed by DCI 0 and DCI 1, the DCI group formed by DCI 2 and DCI 3, and the DCI group formed by DCI 4 and DCI 5 are defined as DCI group indices 0, 1, and 2, respectively, the terminal can feed back DCI missing information for each DCI group in the form of a bitmap formed by three bits, such as 010.

[0402] Example 1-2-b: DCI group index.

[0403] The terminal can feed back the index value of the DCI group that includes the DCI in which the DCI missing occurred.

[0404] More specifically, DCI missing information can be fed back as follows:

[0405] If no DCI missing occurs for all DCIs, the terminal feeds back a value corresponding to a state indicating that no DCI missing occurs.

[0406] If a DCI missing occurs for at least one DCI among the DCIs included in the DCI group corresponding to the DCI group index n, the terminal feeds back a value corresponding to a status indicating that a DCI missing has occurred in the DCI group index n.

[0407] If there are two or more DCI groups that include DCIs in which DCI missing has occurred, the terminal feeds back a value corresponding to a status indicating that DCI missing has occurred in two or more DCI groups.

[0408] Alternatively, you can feedback DCI missing information as follows:

[0409] The number of DCI groups is N G When a dog is detected, the terminal feeds back the index value of the DCI group where DCI missing occurred.

[0410] A specific index value (e.g., N) G ) indicates that no DCI missing occurred for all DCIs. If no DCI missing occurred for all DCIs, the terminal sets an index value (e.g., N) indicating that no DCI missing occurred. G ) provides feedback.

[0411] A specific index value (e.g., N) G +1) indicates that a DCI with a DCI missing occurs in two or more DCI groups. If a DCI with a DCI missing occurs in two or more DCI groups, the terminal sets an index value (e.g., N) indicating that a DCI missing occurs in two or more DCI groups. G +1) Feedback.

[0412] In this case, the number of DCI groups is N G When a dog is called, the number of bits to feed back DCI missing information is log2(N G +2) It can be the same as bits.

[0413] For example, as in Table 12, when the terminal feeds back A / N information for PDSCHs scheduled by DCI 0 to DCI 5 through the same UCI, the terminal may not receive DCI 2 but may successfully receive the remaining DCIs. In this case, when three DCI groups are formed by grouping two DCIs each, and a DCI group formed by DCI 0 and DCI 1, a DCI group formed by DCI 2 and DCI 3, and a DCI group formed by DCI 4 and DCI 5 are defined as DCI group indices 0, 1, and 2, respectively, the terminal may feed back a value indicating that a DCI missing has occurred in a DCI included in DCI group index 1 to the base station in order to feed back DCI missing information.

[0414] Method 2. DCI Missing Feedback to DCI Units Where ACK Does Not Occur

[0415] When a terminal feeds back A / N information for TBs / CBGs scheduled by multiple DCIs to a base station through the same UCI, NACK information included in TBs / CBGs scheduled by the same DCI may have the same DCI missing information. That is, all NACK information included in TBs / CBGs scheduled by the same DCI may be caused by either the same decoding failure or the same DCI missing.

[0416] In addition, for the A / N information for TBs / CBGs scheduled by a specific DCI, if at least one of the A / N information is ACK, none of the NACK information included in the A / N information is NACK caused by missing DCI. That is, the base station can determine that the terminal has successfully received the DCI. Therefore, in the case of such DCI, the terminal does not need to feed back DCI missing information to the base station.

[0417] Accordingly, in the present disclosure, when a terminal feeds back A / N information for a TB / CBG scheduled by a plurality of DCIs to a base station through the same UCI, it is proposed that the terminal feeds back missing information for each DCI to the base station on a DCI basis, but only when all A / N information for the TB / CBGs scheduled by the DCI are NACKs, it feeds back missing information for the corresponding DCI to the base station. In other words, it is proposed that the terminal feeds back DCI missing information for A / Ns for TB / CBGs scheduled by the same DCI to the base station on a per-A / N basis, but only when all A / Ns are NACKs, it feeds back DCI missing information for the corresponding A / Ns to the base station.

[0418] That is, the terminal feeds back DCI missing information to the base station for DCIs for which NACKs occurred for all TBs / CBGs scheduled by the DCI (at least one ACK did not occur), in units of DCIs or in units of A / Ns for TBs / CBGs scheduled by the same DCI.

[0419] [Table 13]

[0420]

[0421] As shown in Table 13 above, a total of 12 TBs, 2 TBs per DCI, are scheduled through 6 DCIs from DCI 0 to DCI 5, and each TB can be composed of 4 CBGs. In this case, the terminal feeds back a total of 48 A / N information to the base station per CBG.

[0422] In Table 13, for the TB / CBGs scheduled by DCI, the DCIs where all NACKs occurred are DCI 2 and DCI 5. In this case, the terminal feeds back the missing information of DCI for each DCI for DCI 2 and DCI 5. That is, the terminal feeds back the missing information of DCI for the A / N information for the CBGs scheduled by DCI 2 and DCI 5, in units of A / N information for the CBGs scheduled by the same DCI.

[0423] Method 2-1.

[0424] When a terminal feeds back A / N information for PDSCHs scheduled by multiple DCIs to a base station, for DCIs among the DCIs scheduling the corresponding PDSCHs, for which A / N information for TB / CBGs scheduled by the DCIs is all NACK, an index can be defined for each DCI, and information on whether the terminal has missed the corresponding DCI can be fed back in units of DCI indexes.

[0425] In other words, when a terminal feeds back A / N information for PDSCHs scheduled by multiple DCIs to a base station, for DCIs among the DCIs that schedule the PDSCHs, for DCIs in which all A / N information for TB / CBGs scheduled by the DCIs are NACKs, the terminal can group the A / Ns for TB / CBGs scheduled by the same DCI and define an index for each A / N group, and feed back DCI missing information of NACK(s) included in the A / N group in units of A / N group indexes.

[0426] For example, in Table 13, for DCIs DCI 2 and DCI 5, which are DCIs in which all A / N information for TB / CBGs scheduled by DCI are NACKs, a DCI index is defined for each DCI. In other words, for DCIs DCI 2 and DCI 5, which are DCIs in Table 13 in which all A / N information for TB / CBGs scheduled by DCI are NACKs, A / Ns for TB / CBGs scheduled by the same DCI are grouped and an A / N group index is displayed for each A / N group. In other words, a DCI index may mean an A / N group index.

[0427] More specifically, the terminal can feed back DCI missing information to the base station on a DCI basis for DCIs for which all A / N information for TB / CBGs scheduled by the DCI is NACK.

[0428] Example 2-1-a. Bitmap

[0429] The terminal can feed back DCI missing information by DCI index in bitmap format.

[0430] At this time, DCIs scheduling PDSCHs are N D When a dog exists, the size L of the bitmap for DCI missing information can be determined as follows.

[0431] Alt 1. The terminal can set the value of L from the base station through signaling such as RRC or MAC-CE.

[0432] Alt 2. The terminal sets the value of L to 'N D It can be determined that x α' is the same. At this time, α can have a value less than or equal to 1. At this time, the terminal can receive the value of α or a value corresponding to 1 / α from the base station through signaling such as RRC or MAC-CE.

[0433] Alternatively, the terminal can apply 0.1 as the value of α.

[0434] The terminal feeds back DCI missing information for each DCI index through bitmap information composed of L-bits. For example, the nth bit in the bitmap may represent DCI missing information for DCI index n. For example, if a specific bit value corresponding to DCI index n in the bitmap is 0, it may mean that the terminal successfully received the DCI corresponding to the DCI index, and if the bit value is 1, it may mean that the terminal did not receive the DCI corresponding to the DCI index.

[0435] The number of DCI indices (the number of DCIs for which all A / N information for TBs / CBGs scheduled by DCI are NACKs) is N N When the size of the bitmap L is N N can be larger. In this case, N of the front (or back) of the bitmap N Only the dog bits are real N N It can be used to indicate DCI missing information for the DCI indices of the dog.

[0436] Alternatively, the number of DCI indices (the number of DCIs for which all A / N information for TBs / CBGs scheduled by DCI are NACKs) is N. N When the size of the bitmap L is N N may be smaller. In this case, DCI missing information may be indicated through a bitmap only for L DCI indices starting from the lowest DCI index (or only for L DCI indices in decreasing order starting from the highest DCI index).

[0437] For example, if the terminal feeds back A / N information for PDSCHs scheduled by DCI 0 to 5 through the same UCI as in Table 13, the terminal may not receive DCI 2 but may successfully receive the remaining DCIs. In this case, the DCIs for which the A / N information for TB / CBGs scheduled by the DCIs are all NACKs may be, for example, DCI 2 and DCI 5. At this time, when the DCI 2 and DCI 5 are defined as DCI indices 0 and 1, respectively, and DCI missing information is fed back using L=2 bits, the terminal may feed back the DCI missing information in the form of a bitmap consisting of 2 bits, as in 10.

[0438] Example 2-1-b. DCI Index

[0439] The terminal can feed back the index value of the DCI where DCI missing occurred.

[0440] At this time, DCIs scheduling PDSCHs are N D When a dog exists, the size of the bit L for feeding back DCI missing information can be determined as follows.

[0441] Alt 1. The terminal can receive the value of L from the base station through signaling such as RRC or MAC-CE. Alternatively, the terminal can receive the value corresponding to L-2 from the base station through signaling such as RRC or MAC-CE.

[0442] Alt 2. The terminal is the value of L log2(N D ·α+2) can be determined to be the same. At this time, α can have a value less than or equal to 1. At this time, the terminal can receive the value of α or a value corresponding to 1 / α from the base station through signaling such as RRC or MAC-CE. Alternatively, the terminal can apply 0.1 as the value of α.

[0443] More specifically, DCI missing information can be fed back as follows:

[0444] If no DCI missing occurs for all DCIs, the terminal feeds back a value corresponding to a state indicating that no DCI missing occurs.

[0445] When a DCI missing occurs for one DCI corresponding to DCI index n, the terminal feeds back a value corresponding to a status indicating that a DCI missing occurred for DCI index n.

[0446] If DCI missing occurs for two or more DCIs, the terminal feeds back a value corresponding to a status indicating that DCI missing occurred for two or more DCIs.

[0447] Alternatively, you can feedback DCI missing information as follows:

[0448] The terminal feeds back the index value of the DCI where DCI missing occurred.

[0449] A specific index value (e.g., 2) L -2) indicates that no DCI missing occurred for all DCIs. If no DCI missing occurred for all DCIs, the terminal sets an index value (e.g., 2) indicating that no DCI missing occurred. L -2) Feedback.

[0450] A specific index value (e.g., 2) L -1) indicates that DCI missing occurred for two or more DCIs. If DCI missing occurred for two or more DCIs, the terminal sets an index value (e.g., 2) indicating that DCI missing occurred for two or more DCIs. L -1) Feedback.

[0451] For example, if the terminal feeds back A / N information for PDSCHs scheduled by DCI 0 to 5 through the same UCI as in Table 13, the terminal may not receive DCI 2 but may successfully receive the remaining DCIs. In this case, when DCI 2 and DCI 5, which are DCIs for which A / N information for TBs / CBGs scheduled by DCIs are all NACKs, are defined as DCI indexes 0 and 1, respectively, and DCI missing information is fed back, the terminal may feed back to the base station a value indicating that the DCI corresponding to DCI index 0 is missing in order to feed back the DCI missing information.

[0452] Taking this into account, the terminal transmits / can transmit feedback on poor quality reception information to the base station when receiving a TB for RV0 and performing HARQ-ACK feedback thereon. Alternatively, the terminal transmits / can transmit feedback on poor quality reception information to the base station when receiving an initial transmission and performing HARQ-ACK feedback thereon.

[0453] B. Method 2-2.

[0454] When a terminal feeds back A / N information for PDSCHs scheduled by multiple DCIs to a base station, for DCIs among the DCIs scheduling the corresponding PDSCHs, for which A / N information for TB / CBGs scheduled by the DCIs is all NACK, the terminal can group the DCIs into multiple groups, define an index for each DCI group, and feed back information on whether the terminal has missed the DCI(s) included in the corresponding DCI group by DCI group.

[0455] In other words, when a terminal feeds back A / N information for PDSCHs scheduled by multiple DCIs to a base station, for DCIs among the DCIs scheduling the corresponding PDSCHs, for DCIs in which all A / N information for TB / CBGs scheduled by the DCIs are NACKs, the terminal groups the DCIs into multiple groups, groups the A / Ns for TB / CBGs scheduled by DCI(s) belonging to the same DCI group, defines an index for each A / N group, and feeds back DCI missing information of NACK(s) included in the A / N group by A / N group. In the following content, the DCI group index may mean the A / N group index.

[0456] For example, DCIs scheduling PDSCHs are N D When a dog exists, N D Among the DCIs, there are N DCIs for which all A / N information for TB / CBGs scheduled by the DCI is NACK. N There may be a dog. In this case, the corresponding N N The DCIs of the dog are N G Can be grouped into groups of dogs.

[0457] Number of DCI groups N G The dog can be determined as follows:

[0458] Alt 1. Terminal is N G The value can be set from the base station through signaling such as RRC and MAC-CE.

[0459] Alt 2. Terminal is N G The value of 'N D It can be determined that x α' is the same. At this time, α can have a value less than or equal to 1. At this time, the terminal can receive the value of α or a value corresponding to 1 / α from the base station through signaling such as RRC or MAC-CE. Alternatively, the value of α can be fixed to a specific value and defined in the standard specification.

[0460] Alt 3. Terminal is N G The value of can always be judged to be equal to 1. At this time, the terminal applies a method such as Alt 1 or Alt 2, but N from the base station G Alternatively, if the α value is not specified, the method of Alt 3 can be applied.

[0461] DCI is N where all A / N information for TB / CBGs scheduled by DCI is NACK. N When a dog exists, each DCI group has ceil(N N / N G ) or floor(N N / N G ) can belong to DCIs.

[0462] More specifically, the terminal can feed back DCI missing information to the base station in units of DCI group indexes as follows. In the following, the DCI group index may refer to the A / N group index.

[0463] Example 2-2-a. Bitmap

[0464] The terminal can feed back DCI missing information by DCI group index in bitmap format. That is, the index information of the DCI group that includes the DCI where the DCI missing occurred can be fed back in bitmap format. The number of DCI groups is N. G When we say dog, the terminal is N G- Feedback of DCI missing information for DCIs included in a DCI group corresponding to each DCI group index is provided through bitmap information composed of bits. For example, if a specific bit value corresponding to a DCI group index n in the bitmap is 0, this means that the terminal has successfully received all DCIs included in the DCI group corresponding to the DCI group index, and if the bit value is 1, this may mean that the terminal has not received at least one DCI among the DCIs included in the DCI group corresponding to the DCI group index.

[0465] Example 2-2-b. DCI group index

[0466] The terminal can feed back the index value of the DCI group that includes the DCI in which the DCI missing occurred.

[0467] More specifically, DCI missing information can be fed back as follows:

[0468] If no DCI missing occurs for all DCIs, the terminal feeds back a value corresponding to a state indicating that no DCI missing occurs.

[0469] If a DCI missing occurs for at least one DCI among the DCIs included in the DCI group corresponding to the DCI group index n, the terminal feeds back a value corresponding to a status indicating that a DCI missing has occurred for the DCI index n.

[0470] If there are two or more DCI groups that include DCIs in which DCI missing has occurred, the terminal feeds back a value corresponding to a status indicating that DCI missing has occurred in two or more DCI groups.

[0471] Alternatively, you can feedback DCI missing information as follows:

[0472] The number of DCI groups is N GWhen a dog is detected, the terminal feeds back the index value of the DCI group where DCI missing occurred.

[0473] A specific index value (e.g., N) G ) indicates that no DCI missing occurred for all DCIs. If no DCI missing occurred for all DCIs, the terminal sets an index value (e.g., N) indicating that no DCI missing occurred. G ) provides feedback.

[0474] A specific index value (e.g., N) G +1) indicates that a DCI with a DCI missing occurs in two or more DCI groups. If a DCI with a DCI missing occurs in two or more DCI groups, the terminal sets an index value (e.g., N) indicating that a DCI missing occurs in two or more DCI groups. G +1) Feedback.

[0475] In this case, the number of DCI groups is N G When a dog is called, the number of bits to feed back DCI missing information is log2(N G +2) It can be the same as bits.

[0476] Method 3. Feedback on whether DCI missing is included in the entire A / N information.

[0477] In order to feed back with low overhead whether or not NACK information caused by DCI missing is included, the present disclosure proposes that when a terminal feeds back A / N information for TBs / CBGs scheduled by multiple DCIs to a base station through the same UCI, the terminal feeds back to the base station information about whether or not DCI missing occurs in the corresponding DCIs. In other words, the terminal proposes to feed back to the base station information about whether or not NACK caused by DCI missing exists among the NACK information fed back to the base station.

[0478] In this case, the DCI missing information can be composed of 1-bit information, which indicates whether the entire A / N information contains a NACK due to DCI missing with very little overhead.

[0479] More specifically, when a terminal feeds back A / N information for PDSCHs scheduled by multiple DCIs to a base station, if there is a DCI among the DCIs scheduling the corresponding PDSCHs that has missed DCI reception, the terminal feeds back the DCI missing information as 1. On the other hand, if there is no DCI that has missed DCI reception, the terminal feeds back the DCI missing information as 0.

[0480] Method 4. DCI Missing Feedback by NACK Group Unit

[0481] When a terminal feeds back A / N information for TB / CBGs scheduled by multiple DCIs to a base station through the same UCI, the terminal can feed back information about NACKs caused by missing DCIs among the NACK information included in the fed-back A / N information to the base station.

[0482] Method 4-1.

[0483] The terminal feeds back information about the index of NACK caused by DCI missing to the base station for information judged as NACK among A / N information for TB / CBGs scheduled by DCI.

[0484] For the information judged as NACK among the A / N information for TB / CBGs scheduled by DCI, the NACK index can be determined in order. For example, if a terminal determines NACK for TB / CBGs scheduled by multiple DCIs, AN When feeding back A / N information to the base station through the same UCI, N of these N If the information of the dog is NACK, the N that is judged as NACK NThe NACK index can be determined based on the characteristic order of the information. For example, if the 0th, 4th, and 5th A / N information among a total of 8 A / N information are NACKs, the 0th, 4th, and 5th A / N information can have 0, 1, and 2 as the NACK index, respectively.

[0485] More specifically, the terminal can feed back DCI missing information for NACK information to the base station as follows.

[0486] Example 4-1-a. Bitmap

[0487] The terminal can feed back DCI missing information for each NACK information in bitmap format. At this time, the DCIs that schedule PDSCHs are N D When a dog exists, the size L of the bitmap for DCI missing information can be determined as follows.

[0488] Alt 1. The terminal can set the value of L from the base station through signaling such as RRC or MAC-CE.

[0489] Alt 2. The terminal sets the value of L to 'N D It can be determined that x α' is the same. At this time, α can have a value less than or equal to 1. At this time, the terminal can receive the value of α or a value corresponding to 1 / α from the base station through signaling such as RRC or MAC-CE. Alternatively, the terminal can apply 0.1 as the value of α.

[0490] The terminal feeds back DCI missing information for each NACK information through bitmap information consisting of L-bits.

[0491] For example, the nth bit in the bitmap may represent DCI missing information for NACK index n. For example, if a specific bit value corresponding to NACK index n in the bitmap is 0, this may mean that the NACK information corresponding to the NACK index is a NACK resulting from a decoding failure, and if the bit value is 1, this may mean that the NACK information is a NACK resulting from failure to receive DCI.

[0492] The number of NACK indices (the number of information judged as NACK among the A / N information for TB / CBGs scheduled by DCI) is N N When the size of the bitmap L is N N can be larger. In this case, N of the front (or back) of the bitmap N Only the dog bits are real N N It can be used to indicate DCI missing information for the NACK indices of the dog.

[0493] Or the number of NACK indices is N N When the size of the bitmap L is N N may be smaller. In this case, DCI missing information may be indicated via a bitmap only for L NACK indices starting from the lowest NACK index (or only for L NACK indices in decreasing order starting from the highest NACK index).

[0494] Example 4-1-b. NACK Index

[0495] The terminal can feed back the NACK index value that occurred due to DCI missing. At this time, the number of A / N information that the terminal feeds back to the base station is N. AN When , L, the size of the bit for feeding back DCI missing information, can be determined as follows.

[0496] Alt 1. The terminal can receive the value of L from the base station through signaling such as RRC or MAC-CE. Alternatively, the terminal can receive the value corresponding to L-2 from the base station through signaling such as RRC or MAC-CE.

[0497] Alt 2. The terminal is the value of L log2(N AN ·α+2) can be determined to be the same. At this time, α can have a value less than or equal to 1. At this time, the terminal can receive the value of α or a value corresponding to 1 / α from the base station through signaling such as RRC or MAC-CE. Alternatively, the terminal can apply 0.1 as the value of α.

[0498] More specifically, DCI missing information can be fed back as follows:

[0499] If the entire NACK is not caused by a DCI miss, the terminal feeds back a value corresponding to a state indicating that no DCI miss occurred.

[0500] If NACK information corresponding to NACK index n is caused by DCI missing, the terminal feeds back a value corresponding to a state indicating that NACK index n is caused by DCI missing.

[0501] If two or more NACKs occur due to DCI missing, the terminal feeds back a value corresponding to a status indicating that two or more NACKs occur due to DCI missing.

[0502] Alternatively, you can feedback DCI missing information as follows:

[0503] The terminal feeds back the index value of the NACK information caused by DCI missing.

[0504] A specific index value (e.g., 2) L-2) may indicate that the entire NACKs were not caused by DCI missing. If the entire NACKs were not caused by DCI missing, the terminal may set an index value (e.g., 2) indicating that DCI missing did not occur. L -2) Feedback.

[0505] A specific index value (e.g., 2) L -1) indicates that two or more NACKs occurred due to DCI missing. If two or more NACKs occurred due to DCI missing, the terminal sets an index value (e.g., 2) indicating that two or more NACKs occurred due to DCI missing. L -1) Feedback.

[0506] Method 4-2.

[0507] The terminal groups the NACK information determined to be NACK among the A / N information for TB / CBGs scheduled by DCI into multiple groups and defines a NACK group index, and feeds back information to the base station on whether the NACK group includes a NACK caused by DCI missing, in units of the NACK group index.

[0508] For example, a terminal may have N for TB / CBGs scheduled by multiple DCIs. AN When feeding back A / N information to the base station through the same UCI, N of these N If the information of the dog is NACK, the N that is judged as NACK N N dog information GA / N information can be grouped into groups and the NACK group index can be determined for each group. For example, if the 0th, 4th, 5th, and 7th A / N information among a total of 10 A / N information are NACKs, they can be grouped into two groups, and the 0th and 4th A / N information can be included in the NACK group with the index 0, and the 5th and 7th A / N information can be included in the NACK group with the index 1.

[0509] The number of A / N information that the terminal feeds back to the base station is N AN When , the number of NACK groups is N G The dog can be determined as follows:

[0510] Alt 1. Terminal is N G The value can be set from the base station through signaling such as RRC and MAC-CE.

[0511] Alt 2. Terminal is N G The value of 'N AN It can be determined that x α' is the same. At this time, α can have a value less than or equal to 1. At this time, the terminal can receive the value of α or a value corresponding to 1 / α from the base station through signaling such as RRC or MAC-CE. Alternatively, the value of α can be fixed to a specific value and defined in the standard specification.

[0512] Alt 3. Terminal is N G The value of can always be judged to be equal to 1. At this time, the terminal applies a method such as Alt 1 or Alt 2, but N from the base station G Alternatively, if the α value is not specified, the method of Alt 3 can be applied.

[0513] DCI is N where all A / N information for TB / CBGs scheduled by DCI is NACK. N When a dog exists, each DCI group has ceil(N N / N G ) or floor(N N / N G) can belong to DCIs.

[0514] Characteristically, only some of the NACK information judged as NACK may be included in the NACK group.

[0515] For example, only when all A / N information for TBs / CBGs scheduled by the same DCI are NACKs, the NACK information can be included in the NACK group. If at least one A / N information for TBs / CBGs scheduled by the same DCI for a specific NACK information is ACK, the NACK information is not included in the NACK group.

[0516] At this time, NACKs scheduled by the same DCI may belong to the same NACK group.

[0517] NACKs scheduled by different DCIs can belong to different NACK groups.

[0518] Alternatively, NACKs scheduled by different DCIs may belong to the same NACK group. In this case, NACKs scheduled by multiple (e.g., Z) DCIs may belong to the same NACK group.

[0519] More specifically, the terminal can feed back DCI missing information to the base station in NACK group index units as follows.

[0520] Example 4-2-a. Bitmap

[0521] The terminal can feed back DCI missing information by NACK group index in bitmap format. That is, NACK group index information including NACKs caused by DCI missing can be fed back in bitmap format. The number of NACK groups is N G When we say dog, the terminal is N G- Feedback information on whether a NACK caused by DCI missing is included in the NACK group corresponding to each NACK group index through bitmap information composed of bits. For example, if a specific bit value corresponding to NACK group index n in the bitmap is 0, it means that all NACK information included in the NACK group corresponding to the NACK group index is NACK caused by decoding failure, and if the bit value is 1, it can mean that the NACK group corresponding to the NACK group index includes a NACK caused by DCI missing.

[0522] Example 4-2-b. DCI Group Index

[0523] The terminal can feed back the index value of the NACK group that includes the DCI in which the DCI missing occurred.

[0524] More specifically, DCI missing information can be fed back as follows:

[0525] If none of the NACKs are due to DCI missing, the terminal feeds back a value corresponding to a state indicating that no DCI missing occurred.

[0526] If at least one NACK among the NACKs included in the NACK group corresponding to the NACK group index n is caused by DCI missing, the terminal feeds back a value corresponding to a state indicating that the NACK group corresponding to the NACK index n includes the NACK caused by DCI missing.

[0527] If there are two or more NACK groups that include NACKs that have occurred due to DCI missing, the terminal feeds back a value corresponding to a status indicating that two or more NACK groups include NACKs that have occurred due to DCI missing.

[0528] Alternatively, you can feedback DCI missing information as follows:

[0529] The number of NACK groups is N G When a dog is detected, the terminal feeds back the index value of the NACK group that includes the NACK caused by DCI missing.

[0530] A specific index value (e.g., N) G ) indicates that no DCI missing occurred for all DCIs. If no DCI missing occurred for all DCIs, the terminal sets an index value (e.g., N) indicating that no DCI missing occurred. G ) provides feedback.

[0531] A specific index value (e.g., N) G +1) indicates that two or more NACK groups contain NACKs caused by DCI missing. If two or more NACK groups contain NACKs caused by DCI missing, the terminal sets an index value (e.g., N) indicating that two or more NACK groups contain NACKs caused by DCI missing. G +1) Feedback.

[0532] In this case, the number of NACK groups is N G When a dog is called, the number of bits to feed back DCI missing information is log2(N G +2) It can be the same as bits.

[0533] Section 5.2. Application of feedback behavior of DCI missing information

[0534] The feedback behavior of DCI missing information as in Section 5.1 above (i.e., Section 5.1) may be applied only in the following cases:

[0535] The terminal can apply the feedback operation of the DCI missing information only when it feeds back A / N information for data scheduled by multiple DCIs to the base station through the same UCI.

[0536] A terminal may apply the feedback operation of DCI missing information only when the base station has configured the terminal to perform the feedback operation of DCI missing information. This configuration information may be configured from the base station to the terminal through signaling such as RRC and / or MAC-CE.

[0537] DCI missing information, such as in Section 5.1 above, can be included in the HARQ-ACK information transmitted by the terminal to the base station and transmitted to the base station together with the A / N information.

[0538] In this case, the bits that constitute the HARQ-ACK information fed back by the terminal may be composed of bits containing A / N information of TB and / or CBG and bits containing DCI missing information.

[0539] When applying this method, the number of bits composing HARQ-ACK may be different when the terminal feeds back DCI missing information to the base station and when it does not.

[0540] In this case, the terminal can determine whether to transmit only A / N information for HARQ-ACK feedback or to transmit DCI missing information together by determining whether to feedback DCI missing information according to the instructions of the base station.

[0541] Accordingly, the contents and number of bits that constitute the HARQ-ACK fed back by the terminal may vary.

[0542] Alternatively, the DCI missing information, as described in Section 5.1 above, may be transmitted to the base station as a UCI independent of the HARQ-ACK information transmitted by the terminal to the base station. This DCI missing information may be transmitted only when the terminal transmits a HARQ-ACK to the base station. Using this method, the UCI containing the DCI missing information can be fed back to the base station only when the terminal feeds back the DCI missing information to the base station.

[0543] The physical channel (e.g., PUCCH, PUSCH) and timing through which the terminal feeds back DCI missing information to the base station may be the same as the timing through which the terminal feeds back HARQ-ACK information related to / corresponding to the DCI missing information.

[0544] The terminal can determine whether to feed back DCI missing information according to the instructions.

[0545] Even if the base station instructs the terminal to provide feedback on missing DCI information, the terminal may not always transmit missing DCI information to the base station. For example, if the terminal does not receive any DCI information, it may not transmit missing DCI information to the base station.

[0546] And / or, if the terminal has a lot of UCI information to transmit and must give up transmitting some of the UCI information, the terminal may not transmit DCI missing information to the base station. In this case, the terminal may include information indicating whether DCI missing information has been transmitted in the HARQ-ACK information and transmit it to the base station. If the terminal does not transmit UCI containing DCI missing information, the terminal may inform the base station that the DCI missing information is not transmitted through the HARQ-ACK. Conversely, if the terminal transmits UCI containing DCI missing information together with the HARQ-ACK, the terminal may inform the base station that the DCI missing information is transmitted through the HARQ-ACK.

[0547] Figure 16 illustrates an operation method of the terminal.

[0548] Referring to FIG. 16, the terminal receives multiple downlink control information (DCI) from the base station (S161).

[0549] For example, a terminal may receive multiple DCI formats (e.g., DCI format 1_0, DCI format 1_1, DCI format 1_2, or DCI format 1_3) for scheduling a PDSCH. The DCI format may include an RV (redundancy version) field. The RV field is a field that plays a very important role in the IR (incremental redundancy)-HARQ (Hybrid Automatic Repeat Request) retransmission process, and may, for example, inform the terminal of which version of redundancy bits to transmit during retransmission. For example, the RV field may be composed of 2 bits, in which case the RV values ​​may have 0, 1, 2, or 3. For example, RV 0 may be used for the initial transmission, and at this time, mainly systematic bits and some parity bits may be transmitted. RV 1, 2, 3, etc. can be used for retransmission, and in this case, different systematic bits and / or parity bits, i.e. different forms of redundant information, can be transmitted compared to when RV 0 is used.

[0550] Each of the above plurality of DCIs may be a DCI that schedules two or more data units.

[0551] The terminal receives a plurality of data units scheduled by the plurality of DCIs from the base station (S162). The plurality of data units may be a plurality of transport blocks or a plurality of code block groups (CBGs). One transport block may include at least one CBG.

[0552] The terminal feeds back HARQ-ACK information for the plurality of data units to the base station, but if there is a specific DCI that is missed during the reception process of the plurality of DCIs, the terminal transmits additional information related to the specific DCI together with the HARQ-ACK information (S163).

[0553] An example of the above-mentioned additional information may be the aforementioned DCI missing information. As described above, the DCI missing information may be information informing the base station of the missing of a specific DCI, but it may also be information related to a terminal requesting retransmission of specific data based on the terminal's failure to receive the specific DCI.

[0554] According to an embodiment, the plurality of DCIs and the specific DCI may be divided into a plurality of groups, and the additional information may be transmitted only for a DCI group including the specific DCI.

[0555] The above specific DCI may be a DCI in which all HARQ-ACK information for related data units is NACK.

[0556] In some embodiments, the terminal may transmit the additional information only when the specific DCI is a DCI in which the value of the RV (redundancy version) field is 0.

[0557] The above additional information may be provided by at least one of the methods included in, for example, the above-described 'Method 1. DCI missing feedback by DCI unit', 'Method 2. DCI missing feedback by DCI unit where ACK has not occurred', 'Method 3. Feedback on whether DCI missing is included in all A / N information', and 'Method 4. DCI missing feedback by NACK group unit'. Specific embodiments thereof have been described in the corresponding methods. For example, when Method 1-1 included in 'Method 1. DCI missing feedback by DCI unit' is applied, specific embodiments thereof have been described in Embodiments 1-1-a, 1-1-b, etc.

[0558] In some embodiments, when DCI schedules multiple TBs at once, the RV value or NDI (new data indicator) information may be different for each TB. In this case, if the RV value is 0 for at least one TB among the TBs scheduled through the DCI, and if reception of the DCI is missed, the terminal may transmit the additional information.

[0559] That is, if the missing specific DCI is a DCI that schedules a plurality of transport blocks, and an RV (redundancy version) value is independently provided for each of the plurality of transport blocks by the specific DCI, and the RV value for at least one transport block among the plurality of transport blocks is determined to be 0, the terminal can feed back the additional information for the specific DCI.

[0560] The NDI may include information that allows a receiver (e.g., a terminal) to identify whether a data block (e.g., a transport block) currently being received is a new transmission or a retransmission of a previously transmitted data block. For example, the NDI consists of 1 bit, and when the NDI value of the current transmission changes (toggles) (e.g., from 0 to 1, or from 1 to 0) compared to the NDI value of the previous transmission, it indicates that the corresponding data block of the current transmission is a new transmission, and when the NDI value of the current transmission is the same as the NDI value of the previous transmission, it indicates that the data block of the previous transmission is a retransmission.

[0561] In an embodiment, when DCI schedules multiple TBs at once, if at least one TB among the multiple TBs is indicated by NDI to be a new transmission (initial transmission), if reception of the DCI is missed, the terminal may feed back the aforementioned additional information.

[0562] That is, if the missing specific DCI is a DCI that schedules a plurality of transport blocks, and an NDI (new data indicator) value is independently provided for each of the plurality of transport blocks by the specific DCI, and the NDI value for at least one transport block among the plurality of transport blocks is determined to be toggled, the terminal can feed back the additional information for the specific DCI.

[0563] That is, the terminal may not always feed back additional information when it determines that a specific DCI is missing, but may feed back additional information only when the specific DCI satisfies a specific condition (e.g., when it is determined that the RV value is 0 for at least one of the multiple TBs scheduled by the specific DCI or that a new transmission is indicated by the NDI).

[0564] In some embodiments, the additional information may be 1-bit information indicating that at least one DCI has been missed during the reception of the plurality of DCIs. In this case, the additional information may not directly indicate a specific DCI for which the DCI reception has been missed, but may indicate that at least one DCI has been missed during the reception of the plurality of DCIs through a small amount of overhead, for example, 1-bit information.

[0565] In some embodiments, the additional information may be configured as a bitmap, the size of which may be equal to the sum of the number of the plurality of DCIs and the number of the specific DCI. In this case, the additional information may explicitly indicate the specific DCI where the reception failure occurred. This method is described above with reference to Table 11.

[0566] Alternatively, the additional information may be configured as a bitmap, and the size of the bitmap may be equal to the number of groups when the plurality of DCIs and the specific DCI are divided into multiple groups. In this case, the additional information may indicate the DCI group that includes the specific DCI. This method has been described above with reference to Table 12.

[0567] In some embodiments, the additional information may be fed back for a DCI only if all data units scheduled by the DCI are fed back with NACKs. This method is described above with reference to Table 13.

[0568] In some embodiments, the terminal may further receive configuration information from the base station that configures the transmission of the additional information. In this case, the additional information may be transmitted to the base station only when the transmission of the additional information is indicated by the configuration information. For example, the base station may provide the configuration information to the terminal via signaling such as RRC or MAC-CE. This is described in detail in Section 5.2.

[0569] Depending on the embodiment, the HARQ-ACK information and the additional information may be transmitted in the same uplink control information (UCI).

[0570] Alternatively, the HARQ-ACK information and the additional information may be transmitted in different uplink control information (UCI). In this case, the additional information may be transmitted only when the HARQ-ACK information is transmitted.

[0571] According to the method according to the present disclosure, when a terminal receives a plurality of DCIs for scheduling PDSCHs and transmits A / N information for data included in the PDSCHs at once (i.e., through the same PUSCH or PUCCH resource), the base station can distinguish whether NACK information for specific data (TB / CBG) is i) a NACK that occurs when the terminal receives the DCI and attempts to receive the specific data but fails to decode it, or ii) the terminal determines it to be a NACK because it failed to receive the DCI. Accordingly, when retransmitting data (TB / CBG) due to missing DCI, the base station can appropriately perform RV index, MCS index indication, etc. In addition, even when retransmitting the data (TB / CBG), it is possible to prevent a problem in which the terminal still fails to properly receive the data (TB / CBG).

[0572] Figure 17 illustrates a signaling process and operation method between a base station and a terminal.

[0573] Referring to Figure 17, the base station provides the terminal with configuration information related to the transmission of additional information (S171). For example, the configuration information may set information related to the transmission of additional information, such as whether the terminal will feed back the aforementioned additional information, and if so, whether to include it in the same UCI as the HARQ-ACK information or in a separate UCI.

[0574] The base station transmits a plurality of DCIs to the terminal (S172), and transmits a plurality of data units (e.g., transport blocks (TBs) or code block groups (CBGs)) scheduled by the plurality of DCIs (S173).

[0575] The terminal generates additional information (related to the retransmission of data scheduled by a specific missing DCI) (S174). For example, the terminal may generate the additional information only if the aforementioned additional information transmission-related configuration information indicates feedback of the additional information. The additional information is described above with reference to FIG. 16.

[0576] The terminal feeds back UCI including HARQ-ACK information and additional information for multiple data units to the base station (S175).

[0577] Figure 18 illustrates a wireless device applicable to the present specification.

[0578] Referring to FIG. 18, the first wireless device (100) and the second wireless device (200) can transmit and receive wireless signals through various wireless access technologies (e.g., LTE, NR).

[0579] A first wireless device (100) includes at least one processor (102) and at least one memory (104), and may further include at least one transceiver (106) and / or at least one antenna (108). The at least one processor (102, hereinafter simply referred to as a processor) controls at least one memory (104, hereinafter simply referred to as a memory) and / or at least one transceiver (106, hereinafter simply referred to as a transceiver or a transceiver), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (102) may process information in the memory (104) to generate first information / signal, and then transmit a wireless signal including the first information / signal via the transceiver (106). In addition, the processor (102) may receive a wireless signal including second information / signal through the transceiver (106), and then store information obtained from signal processing of the second information / signal in the memory (104). The memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may perform some or all of the processes controlled by the processor (102), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. Here, the processor (102) and the memory (104) may be part of a communication modem / circuit / chip designed to implement a wireless communication technology (e.g., LTE, NR). The transceiver (106) may be connected to the processor (102) and may transmit and / or receive a wireless signal through one or more antennas (108). The transceiver (106) may include a transmitter and / or a receiver. The transceiver (106) may be used interchangeably with an RF (Radio Frequency) unit.In this specification, wireless device may also mean a communication modem / circuit / chip.

[0580] The processor (102) receives a plurality of downlink control information (DCI) from a base station, receives a plurality of data units scheduled by the plurality of DCIs from the base station, and feeds back HARQ-ACK information for the plurality of data units to the base station from the terminal. However, if there is a specific DCI that is missed in the process of receiving the plurality of DCIs, additional information related to the specific DCI is transmitted together with the HARQ-ACK information. The specific operation thereof has been described with reference to FIGS. 16 and 17.

[0581] A second wireless device (200) includes at least one processor (202), at least one memory (204), and may further include at least one transceiver (206) and / or at least one antenna (208). The processor (202) controls the memory (204) and / or the transceiver (206), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (202) may process information in the memory (204) to generate third information / signal, and then transmit a wireless signal including the third information / signal via the transceiver (206). In addition, the processor (202) may receive a wireless signal including fourth information / signal via the transceiver (206), and then store information obtained from signal processing of the fourth information / signal in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, the memory (204) may perform some or all of the processes controlled by the processor (202), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. Here, the processor (202) and the memory (204) may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). The transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals via one or more antennas (208). The transceiver (206) may include a transmitter and / or a receiver. The transceiver (206) may be used interchangeably with an RF unit. In this specification, a wireless device may also mean a communication modem / circuit / chip.

[0582] The processor (202) transmits a plurality of downlink control information (DCI) to the terminal, transmits a plurality of data units scheduled by the plurality of DCIs to the terminal, and the base station receives HARQ-ACK information for the plurality of data units from the terminal. At this time, if there is a specific DCI that is missed in the process of receiving the plurality of DCIs by the terminal, the base station receives additional information related to the specific DCI from the terminal together with the HARQ-ACK information. The specific operation thereof has been described with reference to FIGS. 16 and 17.

[0583] Hereinafter, the hardware elements of the wireless device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and / or one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) can generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, proposals and / or methods disclosed herein, and provide the signals to one or more transceivers (106, 206). One or more processors (102, 202) can receive signals (e.g., baseband signals) from one or more transceivers (106, 206) and obtain PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed herein.

[0584] The one or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. The one or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in the one or more processors (102, 202). The one or more processors (102, 202) may also be implemented by at least one computer-readable medium (CRM) containing instructions based on which at least one processor is executed.

[0585] For example, at least one computer readable medium (CRM) including instructions based on being executed by at least one processor performs the operations of receiving a plurality of downlink control information (DCI) from a base station, receiving a plurality of data units scheduled by the plurality of DCIs from the base station, and feeding back HARQ-ACK information for the plurality of data units to the base station, wherein, if there is a specific DCI that is missed in the process of receiving the plurality of DCIs, additional information related to the specific DCI is transmitted together with the HARQ-ACK information. The specific operations have been described with reference to FIGS. 16 and 17.

[0586] The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software in the form of codes, instructions and / or sets of instructions. The firmware or software configured to perform the descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be included in one or more processors (102, 202) or stored in one or more memories (104, 204) and executed by one or more processors (102, 202). The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software in the form of codes, instructions and / or sets of instructions.

[0587] One or more memories (104, 204) may be coupled to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. The one or more memories (104, 204) may be configured as ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer-readable storage media, and / or combinations thereof. The one or more memories (104, 204) may be located internally and / or externally to the one or more processors (102, 202). Additionally, the one or more memories (104, 204) may be coupled to the one or more processors (102, 202) via various technologies, such as wired or wireless connections.

[0588] One or more transceivers (106, 206) can transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or flowcharts of this document, to one or more other devices. One or more transceivers (106, 206) can receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or flowcharts of this document, from one or more other devices. For example, one or more transceivers (106, 206) can be connected to one or more processors (102, 202) and can transmit and receive wireless signals. For example, one or more processors (102, 202) can control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, or wireless signals from one or more other devices. Additionally, one or more transceivers (106, 206) may be coupled to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals / channels, or the like, as referred to in the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed herein, via one or more antennas (108, 208). In this document, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) can convert received user data, control information, wireless signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc. using one or more processors (102, 202).One or more transceivers (106, 206) may convert user data, control information, wireless signals / channels, etc. processed by one or more processors (102, 202) from baseband signals to RF band signals. For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and / or filter.

[0589] Figure 19 illustrates another example of a wireless device.

[0590] According to FIG. 19, the wireless device may include at least one processor (102, 202), at least one memory (104, 204), at least one transceiver (106, 206), and one or more antennas (108, 208).

[0591] The difference between the example of the wireless device described in FIG. 18 and the example of the wireless device in FIG. 19 is that in FIG. 18, the processor (102, 202) and the memory (104, 204) are separated, whereas in the example of FIG. 19, the memory (104, 204) is included in the processor (102, 202). For example, the processor and the memory may constitute a single chipset.

[0592] Fig. 20 illustrates an example of a signal processing module structure. Here, signal processing may be performed in the processor (102, 202) of Fig. 18.

[0593] Referring to FIG. 20, a transmission device (e.g., a processor, a processor and a memory, or a processor and a transceiver) within a terminal or a base station may include a scrambler (301), a modulator (302), a layer mapper (303), an antenna port mapper (304), a resource block mapper (305), and a signal generator (306).

[0594] A transmitting device can transmit one or more codewords. The coded bits within each codeword are scrambled by a scrambler (301) and transmitted over a physical channel. A codeword may also be referred to as a data string and may be equivalent to a transport block, which is a data block provided by the MAC layer.

[0595] The scrambled bits are modulated into complex-valued modulation symbols by a modulator (302). The modulator (302) can modulate the scrambled bits according to a modulation scheme and arrange them into complex-valued modulation symbols that represent positions on a signal constellation. There is no limitation on the modulation scheme, and m-PSK (m-Phase Shift Keying) or m-QAM (m-Quadrature Amplitude Modulation) can be used to modulate the encoded data. The modulator may be referred to as a modulation mapper.

[0596] The complex modulation symbols may be mapped to one or more transmission layers by a layer mapper (303). The complex modulation symbols on each layer may be mapped by an antenna port mapper (304) for transmission on an antenna port.

[0597] The resource block mapper (305) can map the complex modulation symbol for each antenna port to an appropriate resource element within a virtual resource block (VRB) allocated for transmission. The resource block mapper can map the VRB to a physical resource block (PRB) according to an appropriate mapping scheme. The resource block mapper (305) can assign the complex modulation symbol for each antenna port to an appropriate subcarrier and multiplex it according to the user.

[0598] The signal generator (306) can generate a complex-valued time domain OFDM symbol signal by modulating a complex modulation symbol, for example, an antenna-specific symbol, for each antenna port, with a specific modulation method, for example, an Orthogonal Frequency Division Multiplexing (OFDM) method. The signal generator can perform an Inverse Fast Fourier Transform (IFFT) on the antenna-specific symbol, and a Cyclic Prefix (CP) can be inserted into the time domain symbol on which the IFFT is performed. The OFDM symbol is transmitted to a receiving device through each transmitting antenna through digital-to-analog conversion, frequency uplink conversion, etc. The signal generator can include an IFFT module, a CP inserter, a Digital-to-Analog Converter (DAC), a frequency uplink converter, etc.

[0599] Fig. 21 illustrates another example of the signal processing module structure within a transmission device. Here, signal processing may be performed in a processor of a terminal / base station, such as the processor (102, 202) of Fig. 18.

[0600] Referring to FIG. 21, a transmission device (e.g., a processor, a processor and a memory, or a processor and a transceiver) within a terminal or base station may include a scrambler (401), a modulator (402), a layer mapper (403), a precoder (404), a resource block mapper (405), and a signal generator (406).

[0601] The transmitting device can transmit coded bits within a codeword through a physical channel after scrambling the coded bits within the codeword by a scrambler (401).

[0602] The scrambled bits are modulated into complex modulation symbols by a modulator (402). The modulator can modulate the scrambled bits according to a predetermined modulation scheme and arrange them into complex modulation symbols representing positions on a signal constellation. There is no limitation on the modulation scheme, and pi / 2-BPSK (pi / 2-Binary Phase Shift Keying), m-PSK (m-Phase Shift Keying), or m-QAM (m-Quadrature Amplitude Modulation) can be used to modulate the encoded data.

[0603] The above complex modulation symbol can be mapped to one or more transmission layers by the layer mapper (403).

[0604] The complex modulation symbols on each layer can be precoded by the precoder (404) for transmission on the antenna ports. Here, the precoder may perform precoding after performing transform precoding on the complex modulation symbols. Alternatively, the precoder may perform precoding without performing transform precoding. The precoder (404) may process the complex modulation symbols in a MIMO manner according to multiple transmission antennas to output antenna-specific symbols and distribute the antenna-specific symbols to the corresponding resource block mapper (405). The output z of the precoder (404) can be obtained by multiplying the output y of the layer mapper (403) by the precoding matrix W of NХM. Here, N is the number of antenna ports and M is the number of layers.

[0605] The resource block mapper (405) maps the demodulation modulation symbol for each antenna port to the appropriate resource element within the virtual resource block allocated for transmission.

[0606] The resource block mapper (405) can assign complex modulation symbols to appropriate subcarriers and multiplex them according to the user.

[0607] The signal generator (406) can generate a complex-valued time domain OFDM (Orthogonal Frequency Division Multiplexing) symbol signal by modulating a complex modulation symbol with a specific modulation method, for example, OFDM. The signal generator (406) can perform an Inverse Fast Fourier Transform (IFFT) on an antenna-specific symbol, and a Cyclic Prefix (CP) can be inserted into the time domain symbol on which the IFFT has been performed. The OFDM symbol is transmitted to a receiving device through each transmitting antenna after going through digital-to-analog conversion, frequency upconversion, etc. The signal generator (406) can include an IFFT module, a CP inserter, a Digital-to-Analog Converter (DAC), a frequency uplink converter, etc.

[0608] The signal processing process of the receiving device may be configured in reverse order of the signal processing process of the transmitter. Specifically, the processor of the receiving device performs decoding and demodulation on a wireless signal received externally through the antenna port(s) of the transceiver. The receiving device may include a plurality of multiple receiving antennas, and each signal received through the receiving antenna is restored to a baseband signal and then multiplexed and MIMO demodulated to be restored to a data sequence originally intended to be transmitted by the transmitting device. The receiving device (1820) may include a signal restorer for restoring the received signal to a baseband signal, a multiplexer for combining and multiplexing the received and processed signals, and a channel demodulator for demodulating the multiplexed signal sequence into a corresponding codeword. The signal restorer, the multiplexer, and the channel demodulator may be configured as an integrated module performing their functions or as individual modules. More specifically, the signal restorer may include an analog-to-digital converter (ADC) that converts an analog signal into a digital signal, a CP remover that removes a CP from the digital signal, an FFT module that applies an FFT (fast Fourier transform) to a signal from which the CP has been removed to output a frequency domain symbol, and a resource element demapper / equalizer that restores the frequency domain symbol to an antenna-specific symbol. The antenna-specific symbol is restored to a transmission layer by a multiplexer, and the transmission layer is restored to a codeword that the transmitter intended to transmit by a channel demodulator.

[0609] FIG. 22 illustrates an example of a wireless communication device according to an implementation example of the present disclosure.

[0610] Referring to FIG. 22, a wireless communication device, for example, a terminal, may include at least one of a processor (2310) such as a digital signal processor (DSP) or a microprocessor, a transceiver (2335), a power management module (2305), an antenna (2340), a battery (2355), a display (2315), a keypad (2320), a global positioning system (GPS) chip (2360), a sensor (2365), a memory (2330), a subscriber identification module (SIM) card (2325), a speaker (2345), and a microphone (2350). There may be a plurality of antennas and processors.

[0611] The processor (2310) can implement the functions, procedures, and methods described in this specification. The processor (2310) of FIG. 22 may be the processor (102, 202) of FIG. 18.

[0612] Memory (2330) is connected to the processor (2310) and stores information related to the processor's operation. The memory may be located internally or externally to the processor and may be connected to the processor via various technologies, such as wired or wireless connections. The memory (2330) of FIG. 22 may be the memory (104, 204) of FIG. 18.

[0613] A user may input various types of information, such as a phone number, using various techniques, such as pressing buttons on a keypad (2320) or activating sound using a microphone (2350). The processor (2310) may receive and process the user's information and perform an appropriate function, such as dialing the entered phone number. In some scenarios, data may be retrieved from a SIM card (2325) or memory (2330) to perform the appropriate function. In some scenarios, the processor (2310) may display various types of information and data on a display (2315) for the user's convenience.

[0614] A transceiver (2335) is coupled to a processor (2310) and transmits and / or receives wireless signals, such as radio frequency (RF) signals. The processor may control the transceiver to initiate communication or transmit wireless signals containing various types of information or data, such as voice communication data. The transceiver includes a transmitter and a receiver for transmitting and receiving wireless signals. An antenna (2340) may facilitate the transmission and reception of wireless signals. In some implementations, upon receiving a wireless signal, the transceiver may forward and convert the signal to a baseband frequency for processing by the processor. The processed signal may be processed by various techniques, such as being converted into audible or readable information for output through a speaker (2345). The transceiver of FIG. 22 may be the transceiver (106, 206) of FIG. 18.

[0615] Although not shown in FIG. 22, various components, such as a camera and a Universal Serial Bus (USB) port, may be additionally included in the terminal. For example, the camera may be connected to the processor (2310).

[0616] Fig. 22 is only one implementation example for a terminal, and the implementation examples are not limited thereto. The terminal does not necessarily have to include all the elements of Fig. 22. For example, some components, such as a keypad (2320), a Global Positioning System (GPS) chip (2360), a sensor (2365), and a SIM card (2325), may not be essential elements, and in this case, may not be included in the terminal.

[0617] Fig. 23 illustrates a communication system (1) applicable to this specification.

[0618] Referring to FIG. 23, a communication system (1) applied to the present specification includes a wireless device, a base station, and a network. Here, the wireless device refers to a device that performs communication using a wireless access technology (e.g., 5G NR (New RAT), LTE (Long Term Evolution)) and may be referred to as a communication / wireless / 5G device. Although not limited thereto, the wireless device may include a robot (100a), a vehicle (100b-1, 100b-2), an XR (eXtended Reality) device (100c), a hand-held device (100d), a home appliance (100e), an IoT (Internet of Things) device (100f), and an AI device / server (400). For example, the vehicle may include a vehicle equipped with a wireless communication function, an autonomous vehicle, a vehicle capable of performing vehicle-to-vehicle communication, etc. Here, the vehicle may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone). XR devices include AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) devices, and can be implemented in the form of HMD (Head-Mounted Device), HUD (Head-Up Display) installed in a vehicle, television, smartphone, computer, wearable device, home appliance, digital signage, vehicle, robot, etc. Mobile devices can include smartphone, smart pad, wearable device (e.g., smart watch, smart glass), computer (e.g., laptop, etc.), etc. Home appliances can include TV, refrigerator, washing machine, etc. IoT devices can include sensors, smart meters, etc. For example, base stations and networks can also be implemented as wireless devices, and a specific wireless device (200a) can act as a base station / network node to other wireless devices.

[0619] Wireless devices (100a to 100f) can be connected to a network (300) via a base station (200). Artificial Intelligence (AI) technology can be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (400) via the network (300). The network (300) can be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, etc. The wireless devices (100a to 100f) can communicate with each other via the base station (200) / network (300), but can also communicate directly (e.g., sidelink communication) without going through the base station / network. For example, vehicles (100b-1, 100b-2) can communicate directly (e.g., V2V (Vehicle to Vehicle) / V2X (Vehicle to Everything) communication). In addition, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (100a to 100f).

[0620] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (100a~100f) / base stations (200), and base stations (200) / base stations (200). Here, wireless communication / connection can be achieved through various wireless access technologies (e.g., 5G NR) such as uplink / downlink communication (150a), sidelink communication (150b) (or D2D communication), and communication between base stations (150c) (e.g., relay, IAB (Integrated Access Backhaul). Through wireless communication / connection (150a, 150b, 150c), wireless devices and base stations / wireless devices, and base stations and base stations can transmit / receive wireless signals to each other. For example, wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, at least some of various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), and resource allocation processes can be performed based on various proposals of the present specification.

[0621] Meanwhile, NR supports multiple numerologies (or subcarrier spacing (SCS)) to support various 5G services. For example, an SCS of 15 kHz supports a wide area in traditional cellular bands; an SCS of 30 kHz / 60 kHz supports dense urban areas, lower latency, and wider carrier bandwidth; and an SCS of 60 kHz or higher supports a bandwidth greater than 24.25 GHz to overcome phase noise.

[0622] The NR frequency band can be defined by two types of frequency ranges (FR1, FR2). The numerical values ​​of the frequency ranges can be changed, and for example, the frequency ranges of the two types (FR1, FR2) can be as shown in Table 14 below. For convenience of explanation, among the frequency ranges used in the NR system, FR1 can mean the "sub 6 GHz range", and FR2 can mean the "above 6 GHz range" and can be called millimeter wave (mmW).

[0623] [Table 14]

[0624]

[0625] As described above, the numerical value of the frequency range of the NR system can be changed. For example, FR1 may include a band from 410 MHz to 7125 MHz, as shown in Table 15 below. For example, FR1 may include a frequency band above 6 GHz (or 5850, 5900, 5925 MHz, etc.). For example, the frequency band above 6 GHz (or 5850, 5900, 5925 MHz, etc.) included within FR1 may include an unlicensed band. The unlicensed band may be used for various purposes, such as for vehicle communications (e.g., autonomous driving).

[0626] [Table 15]

[0627]

[0628] The claims set forth in this specification may be combined in various ways. For example, the technical features of the method claims of this specification may be combined and implemented as a device, and the technical features of the device claims of this specification may be combined and implemented as a method. Furthermore, the technical features of the method claims and the technical features of the device claims of this specification may be combined and implemented as a device, and the technical features of the method claims and the technical features of the device claims of this specification may be combined and implemented as a method.

Claims

1. In the method, The terminal receives multiple downlink control information (DCI) from the base station, The terminal receives a plurality of data units scheduled by the plurality of DCIs from the base station, and The terminal feeds back HARQ-ACK information for the plurality of data units to the base station, A method characterized in that, when there is a specific DCI that is missed during the reception process of the plurality of DCIs, the terminal transmits additional information related to the specific DCI together with the HARQ-ACK information.

2. A method according to claim 1, wherein each of the plurality of DCIs schedules two or more data units.

3. A method according to claim 1, wherein the plurality of data units are a plurality of transport blocks or a plurality of code block groups (CBGs).

4. A method characterized in that in the first paragraph, the plurality of DCIs and the specific DCI are divided into a plurality of groups, and the additional information is transmitted only for the DCI group including the specific DCI.

5. A method according to claim 1, characterized in that the specific DCI is a DCI in which all HARQ-ACK information for related data units is NACK.

6. A method according to claim 1, characterized in that the additional information is 1-bit information indicating that reception of at least one DCI has been missed during the reception process of the plurality of DCIs.

7. A method according to claim 1, characterized in that the additional information is transmitted only when the specific DCI is a DCI in which the value of the RV (redundancy version) field is 0.

8. A method according to claim 1, wherein the additional information is configured as a bitmap, and the size of the bitmap is equal to the sum of the number of the plurality of DCIs and the number of the specific DCIs.

9. A method according to claim 1, wherein the additional information is configured as a bitmap, and the size of the bitmap is the same as the number of groups when the plurality of DCIs and the specific DCI are divided into a plurality of groups.

10. A method according to claim 1, characterized in that further setting information for setting transmission of the additional information is received from the base station.

11. A method characterized in that, in the 10th paragraph, the additional information is transmitted to the base station only when transmission of the additional information is instructed by the setting information.

12. A method according to claim 1, characterized in that the HARQ-ACK information and the additional information are transmitted in the same uplink control information (UCI).

13. A method according to claim 1, wherein the HARQ-ACK information and the additional information are transmitted in different uplink control information (UCI), and the additional information is transmitted only when the HARQ-ACK information is transmitted.

14. A method characterized in that, in the first paragraph, the additional information is fed back for the DCI only when all NACKs are fed back for all data units scheduled by the DCI.

15. A method according to claim 1, wherein the specific DCI is a DCI that schedules a plurality of transport blocks, an RV (redundancy version) value is independently provided for each of the plurality of transport blocks by the specific DCI, and when the RV value for at least one transport block among the plurality of transport blocks is determined to be 0, the terminal feeds back the additional information for the specific DCI.

16. A method according to claim 1, wherein the specific DCI is a DCI that schedules a plurality of transport blocks, an NDI (new data indicator) value is independently provided for each of the plurality of transport blocks by the specific DCI, and when it is determined that the NDI value for at least one transport block among the plurality of transport blocks is toggled, the terminal feeds back the additional information for the specific DCI.

17. The terminal is, At least one transceiver; At least one memory; and At least one processor operably coupled with said at least one memory and said at least one transceiver, wherein said at least one memory comprises instructions that are executed by said at least one processor to perform operations, The above actions are, Receive multiple downlink control information (DCI) from a base station, Receive a plurality of data units scheduled by the plurality of DCIs from the base station, and Including feeding back HARQ-ACK information for the plurality of data units to the base station, A terminal characterized in that, when there is a specific DCI that is missed during the reception process of the plurality of DCIs, additional information related to the specific DCI is transmitted together with the HARQ-ACK information.

18. A terminal according to claim 17, wherein each of the plurality of DCIs schedules two or more data units.

19. A terminal according to claim 17, wherein the plurality of data units are a plurality of transport blocks or a plurality of code block groups (CBGs).

20. A terminal characterized in that, in paragraph 17, the plurality of DCIs and the specific DCI are divided into a plurality of groups, and the additional information is transmitted only for the DCI group including the specific DCI.

21. In paragraph 17, the terminal is characterized in that the specific DCI is a DCI in which all HARQ-ACK information for related data units is NACK.

22. A terminal according to claim 17, wherein the additional information is 1-bit information indicating that reception of at least one DCI has been missed during the reception process of the plurality of DCIs.

23. A terminal characterized in that, in paragraph 17, the additional information is transmitted only when the specific DCI is a DCI in which the value of the RV (redundancy version) field is 0.

24. A terminal characterized in that in paragraph 17, the additional information is configured as a bitmap, and the size of the bitmap is equal to the sum of the number of the plurality of DCIs and the number of the specific DCIs.

25. A terminal characterized in that, in paragraph 17, the additional information is configured as a bitmap, and the size of the bitmap is the same as the number of groups when the plurality of DCIs and the specific DCI are divided into a plurality of groups.

26. A terminal characterized in that, in paragraph 17, further receives setting information for setting transmission of the additional information from the base station.

27. A terminal characterized in that, in paragraph 26, the additional information is transmitted to the base station only when transmission of the additional information is instructed by the setting information.

28. A terminal characterized in that, in paragraph 17, the HARQ-ACK information and the additional information are transmitted while being included in the same uplink control information (UCI).

29. A terminal according to claim 17, wherein the HARQ-ACK information and the additional information are transmitted in different uplink control information (UCI), and the additional information is transmitted only when the HARQ-ACK information is transmitted.

30. A terminal characterized in that, in paragraph 17, the additional information is fed back for the DCI only when all NACKs are fed back for all data units scheduled by the DCI.

31. A terminal characterized in that, in paragraph 17, the specific DCI is a DCI that schedules a plurality of transport blocks, an RV (redundancy version) value is independently provided for each of the plurality of transport blocks by the specific DCI, and when the RV value for at least one transport block among the plurality of transport blocks is determined to be 0, the additional information for the specific DCI is fed back.

32. In the 17th paragraph, the specific DCI is a DCI that schedules a plurality of transport blocks, and an NDI (new data indicator) value is independently provided for each of the plurality of transport blocks by the specific DCI, and when it is determined that the NDI value for at least one transport block among the plurality of transport blocks is toggled, the terminal is characterized in that the additional information for the specific DCI is fed back.

33. The device, At least one memory; and At least one processor operably coupled to at least one memory, wherein said at least one memory comprises instructions that are executed by said at least one processor to perform operations, The above actions are, Receive multiple downlink control information (DCI) from a base station, Receive a plurality of data units scheduled by the plurality of DCIs from the base station, and Including feeding back HARQ-ACK information for the plurality of data units to the base station, A device characterized in that, when there is a specific DCI that is missed during the reception process of the plurality of DCIs, additional information related to the specific DCI is transmitted together with the HARQ-ACK information.

34. At least one computer readable medium (CRM) containing instructions based on being executed by at least one processor, An operation of receiving multiple downlink control information (DCI) from a base station, An operation of receiving a plurality of data units scheduled by the plurality of DCIs from the base station, and An operation of feeding back HARQ-ACK information for the above multiple data units to the base station is performed, A CRM characterized in that, when there is a specific DCI that is missed during the reception process of the plurality of DCIs, additional information related to the specific DCI is transmitted together with the HARQ-ACK information.

35. In the method, The base station transmits multiple downlink control information (DCI) to the terminal, The base station transmits to the terminal a plurality of data units scheduled by the plurality of DCIs, and The base station receives HARQ-ACK information for the plurality of data units from the terminal, A method characterized in that, when there is a specific DCI that is missed during the reception process of the plurality of DCIs of the terminal, the base station receives additional information related to the specific DCI from the terminal together with the HARQ-ACK information.

36. The base station, At least one transceiver; At least one memory; and At least one processor operably coupled with said at least one memory and said at least one transceiver, wherein said at least one memory comprises instructions that are executed by said at least one processor to perform operations, The above actions are, Transmit multiple downlink control information (DCI) to the terminal, Transmitting a plurality of data units scheduled by the plurality of DCIs to the terminal, and Including receiving HARQ-ACK information for the plurality of data units from the terminal, A base station characterized in that, when there is a specific DCI that is missed during the reception process of the plurality of DCIs of the terminal, the at least one processor receives additional information related to the specific DCI from the terminal together with the HARQ-ACK information.

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