Method, apparatus, and system for transmitting a HARQ-ACK codebook in a wireless communication system.

Abstract

To provide a method and apparatus for efficiently transmitting and receiving signals in a wireless communication system.SOLUTION: The present invention relates to a wireless communication system and, more specifically, to a method and an apparatus therefor, the method comprising the steps of: receiving a PDCCH for multi-slot scheduling; determining a PDSCH candidate for each slot on the basis of information in the PDCCH; and transmitting a semi-static HARQ-ACK codebook on the basis of the determined PDSCH candidate of each slot.SELECTED DRAWING: Figure 20

Description

[Technical Field]

[0001] The present invention relates to a wireless communication system, and more particularly to a method, apparatus, and system for transmitting a HARQ-ACK codebook in a wireless communication system. [Background technology]

[0002] 3GPP (registered trademark, same below) LTE(-A) defines uplink / downlink physical channels for transmitting physical layer signals. For example, it defines physical uplink shared channels (PUSCH) for transmitting data on the uplink, physical uplink control channels (PUCCH) for transmitting control signals, and physical random access channels (PRACH). On the downlink, it includes physical downlink shared channels (PDSCH) for transmitting data, as well as physical control format indicator channels (PCFICH), physical downlink control channels (PDCCH), and physical hybrid ARQ indicator channels (PHICH) for transmitting L1 / L2 control signals.

[0003] Of the aforementioned channels, the downlink control channel (PDCCH / EPDCCH) is a channel used by a base station to transmit uplink / downlink scheduling allocation control information, uplink transmit power control information, and other control information to one or more terminals. Because there are limitations on the resources that a base station can use for the PDCCH that it can transmit at one time, it is not possible to assign different resources to each terminal, and control information should be transmitted to any terminal by sharing resources. For example, in 3GPP LTE(-A), four REs (Resource Elements) are bundled to create a REG (Resource Element Group), which creates nine CCEs (Control Channel Elements). One or more CCEs are combined to inform terminals of the resources that can be sent, and many terminals share and use the CCEs. Here, the number of CCEs that are combined is called the CCE combination level, and the resources to which CCEs are allocated according to the possible CCE combination level is called the search space. There are two types of search spaces: a common search space defined for each base station and a terminal-specific or UE-specific search space defined for each terminal. The terminal decodes all possible CCE combinations in the search space and determines whether it matches its own PDCCH based on the user equipment (UE) identifier contained in the PDCCH. Therefore, such terminal operation inevitably involves a long decoding time for the PDCCH and consumes a lot of energy.

[0004] Following the commercialization of 4G communication systems, efforts are being made to develop improved 5G or pre-5G communication systems to meet the increasing demand for wireless data traffic. For this reason, 5G or pre-5G communication systems are referred to as Beyond 4G Network systems or Post LTE systems. To achieve high data transmission rates, 5G communication systems are being considered for implementation in ultra-high frequency (mmWave) bands (e.g., 60 GHz bands). To mitigate path loss in propagation and increase propagation distance in ultra-high frequency bands, beamforming, massive multiplexing-in-output (massive MIMO), full-dimensional multiplexing-in-output (FD-MIMO), array antennas, analog beamforming, and large-scale antenna technologies are being discussed for 5G communication systems. Furthermore, in order to improve the system network, 5G communication systems are undergoing technological development, including advanced small cells, cloud radio access networks (cloud RAN), ultra-dense networks, device-to-device communication (D2D), wireless backhaul, moving networks, cooperative communication, CoMP (Coordinated Multi-Points), and interference cancellation.In addition, 5G systems have seen the development of advanced coding modulation (ACM) methods such as FQAM (Hybrid FSK and QAM Modulation) and SWSC (Sliding Window Superposition Coding), as well as advanced access technologies such as FBMC (Filter Bank Multi Carrier), NOMA (non-orthogonal multiple access), and SCMA (sparse code multiple access).

[0005] Meanwhile, the internet, a human-centered interconnected network where humans generate and consume information, is evolving into the Internet of Things (IoT) network, where distributed components such as objects exchange and process information. Internet of Everything (IoE) technology, which combines IoT technology with big data processing technologies via connections to cloud servers and other systems, is also emerging. To realize IoT, technological elements such as sensing technology, wired and wireless communication and network infrastructure, service interface technology, and security technology are required. Recently, technologies such as sensor networks for connecting objects, machine-to-machine (M2M), and machine-type communication (MTC) are being researched. In an IoT environment, intelligent IT services are provided that collect and analyze data generated from connected objects to create new value in human life. IoT, through the integration and combination of conventional IT technologies and various industries, is being applied to fields such as smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart home appliances, and advanced medical services.

[0006] Therefore, various attempts are being made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, machine-to-machine communication, and MTC are being realized through 5G communication technologies such as beamforming, MIMO, and array antennas. As mentioned above, the application of cloud radio access networks (cloud RAN) as a big data processing technology can also be considered an example of the fusion of 5G technology and IoT technology.

[0007] Generally, mobile communication systems were developed to provide voice services while ensuring user activity. However, mobile communication systems have gradually expanded their service scope to include data services in addition to voice services, and have now developed to the point where they can provide high-speed data services. However, due to resource shortages and users' demand for even faster services, there is a need for more advanced mobile communication systems in service today.

[0008] As mentioned above, future 5G technology will require lower latency data transmission due to the emergence of new applications such as real-time control and the tactile internet, and the required latency for 5G data is expected to drop to 1 ms. 5G aims to provide data latency that is approximately 10 times lower than before. To solve this problem, 5G is expected to propose a communication system that utilizes mini-slots with even shorter TTI periods (e.g., 0.2 ms) in addition to conventional slots (or subframes). [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] The object of the present invention is to provide a method and apparatus for efficiently transmitting and receiving signals in a wireless communication system. Another object of the present invention is to provide a method and apparatus for efficiently transmitting a HARQ-ACK codebook in a wireless communication system. Here, the wireless communication system may include a 3GPP-based wireless communication system, for example, a 3GPP NR-based wireless communication system.

[0010] The object of the present invention is not limited to what is specifically stated herein. [Means for solving the problem]

[0011] In one aspect of the present invention, a terminal used in a wireless communication system includes a communication module and a processor that controls the communication module, wherein the processor receives a PDCCH (physical downlink control channel) having the following information:

[0012] - Index information pointing to an entry in the TDRA (time-domain resource allocation) table for PDSCH (physical downlink shared channel) allocation, and

[0013] - K1 set for PDSCH-to-HARQ (hybrid automatic repeat and request) slot timing {K1 i Timing information indicating a single value within (i=1,2,...); when slot n is indicated by the timing information, for all K1 values ​​in the K1 set, slot n-K1 iThe terminal is provided with a set of K1s at the time of determining the PDSCH candidates, where the K1 set is replaced by the union of the following K set #i, based on the fact that at least one entry in the TDRA table is associated with a plurality of PDCCH-to-PDSCH slot timing K0 values:

[0014] - K set #i:{K1 i +d1,K1 i +d2,...,K1 i +d N},

[0015] Here, d k (k=1,2,...,N) corresponds to the slot index difference between the last slot that can be PDSCH assigned and the kth slot that can be PDSCH assigned, based on the multiple PDCCH-to-PDSCH timing K0 values, across all entries in the TDRA table.

[0016] Another aspect of the present invention is a method used by a terminal in a wireless communication system, comprising the step of receiving a PDCCH (physical downlink control channel) having the following information:

[0017] - Index information pointing to an entry in the TDRA (time-domain resource allocation) table for PDSCH (physical downlink shared channel) allocation, and

[0018] - K1 set for PDSCH-to-HARQ (hybrid automatic repeat and request) slot timing {K1 i}(i = 1, 2,...) Timing information indicating a value within; when slot n is indicated by the timing information, for all K1 values within the K1 set, slot n - K1 i Determining PDSCH candidates for; and transmitting a semi-static HARQ-ACK codebook in slot n based on the determined PDSCH candidates for each slot, based on at least one entry in the TDRA table being associated with a plurality of PDCCH-to-PDSCH slot timing K0 values, a method is provided in which the K1 set is replaced by the union of the following K sets #i at the time of determining the PDSCH candidates:

[0019] - K set #i: {K1 i + d1, K1 i + d2,..., K1 i + d N},

[0020] where d k (k = 1, 2,..., N) corresponds to the slot index difference between the last slot where PDSCH allocation is possible and the k-th slot where PDSCH allocation is possible, based on the plurality of PDCCH-to-PDSCH timing K0 values, across all entries in the TDRA table.

[0021] As yet another aspect of the present invention, a base station used in a wireless communication system, comprising a communication module; and a processor for controlling the communication module, the processor transmitting a PDCCH (physical downlink control channel) having the following information:

[0022] - Index information indicating an entry in a TDRA (time-domain resource allocation) table for PDSCH (physical downlink shared channel) allocation, and

[0023] - K1 set for PDSCH-to-HARQ (hybrid automatic repeat and request) slot timing {K1 i Timing information indicating a single value within (i=1,2,...); when slot n is indicated by the timing information, for all K1 values ​​in the K1 set, slot n-K1 i A base station is provided in which, at the time of determining the PDSCH candidates, the K1 set is replaced by the union of the following K sets #i, based on the PDSCH candidates for each determined slot, and based on the fact that at least one entry in the TDRA table is associated with a plurality of PDCCH-to-PDSCH slot timing K0 values, the K1 set is replaced by the union of the following K sets #i:

[0024] - K set #i:{K1 i +d1,K1 i +d2,...,K1 i +d N},

[0025] Here, d k (k=1,2,...,N) corresponds to the slot index difference between the last slot that can be PDSCH assigned and the kth slot that can be PDSCH assigned, based on the multiple PDCCH-to-PDSCH timing K0 values, across all entries in the TDRA table.

[0026] In yet another aspect of the present invention, a method used by a base station in a wireless communication system, comprising the step of transmitting a PDCCH (physical downlink control channel) having the following information:

[0027] - Index information pointing to an entry in the TDRA (time-domain resource allocation) table for PDSCH (physical downlink shared channel) allocation, and

[0028] - K1 set for PDSCH-to-HARQ (hybrid automatic repeat and request) slot timing {K1 i Timing information indicating a single value within (i=1,2,...); when slot n is indicated by the timing information, for all K1 values ​​in the K1 set, slot n-K1 i A method is provided in which, at the time of determining the PDSCH candidates, the K1 set is replaced by the union of the following K sets #i, based on the fact that at least one entry in the TDRA table is associated with a plurality of PDCCH-to-PDSCH slot timing K0 values:

[0029] - K set #i:{K1 i +d1,K1 i +d2,...,K1 i +d N},

[0030] Here, d k (k=1,2,...,N) corresponds to the slot index difference between the last slot that can be PDSCH assigned and the kth slot that can be PDSCH assigned, based on the multiple PDCCH-to-PDSCH timing K0 values, across all entries in the TDRA table.

[0031] Preferably, the subcarrier spacing (SCS) applied to the slot transmitting the PDCCH and the SCS applied to the slot transmitting the semistatic HARQ-ACK codebook may be the same.

[0032] Preferably, for each of the determined slots, multiple HARQ-ACK opportunities are sequentially assigned to non-overlapping PDSCH candidates, with the last symbol being the earliest PDSCH candidate, and the semistatic HARQ-ACK codebook may be constructed based on these multiple HARQ-ACK opportunities.

[0033] Preferably, when time-domain bundling is applied to the semi-static HARQ-ACK codebook, the multiple HARQ-ACK opportunities may be allocated based on the PDSCH candidate of the last slot where PDSCH allocation is possible for each bundling group, based on each entry in the TDRA table.

[0034] Preferably, the wireless communication system may include a 3GPP (3rd generation partnership project) NR (new radio) based wireless communication system. [Effects of the Invention]

[0035] According to an example of the present invention, a method and apparatus for efficiently transmitting and receiving signals in a wireless communication system can be provided. Furthermore, according to an example of the present invention, a method and apparatus for efficiently transmitting a HARQ-ACK codebook in a wireless communication system can be provided. Here, the wireless communication system may include a 3GPP-based wireless communication system, for example, a 3GPP NR-based wireless communication system.

[0036] The effects obtained from the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those with ordinary skill in the art to which the present invention pertains from the following description. [Brief explanation of the drawing]

[0037] [Figure 1] This figure shows an example of a wireless frame structure used in wireless communication systems. [Figure 2] This figure shows an example of a downlink (DL) / uplink (UL) slot structure in a wireless communication system. [Figure 3] This diagram illustrates the physical channels used in 3GPP systems (e.g., NR) and a general signal transmission method using those physical channels. [Figure 4] This figure shows the SS / PBCH block for initial cell access in a 3GPP NR system. [Figure 5] This diagram shows the procedure for transmitting control information and control channels in a 3GPP NR system. [Figure 6] This diagram shows the CORESET to which PDCCH is transmitted in a 3GPP NR system. [Figure 7] This diagram shows how to configure the PDCCH search space in a 3GPP NR system. [Figure 8] This is a conceptual diagram explaining career integration. [Figure 9] This is a diagram illustrating terminal carrier communication and multi-carrier communication. [Figure 10] This figure shows an example where the cross-carrier scheduling method is applied. [Figure 11] This diagram shows the scheduling of PDSCH (Physical Downlink Shared Channel). [Figure 12] This diagram shows the scheduling for PUSCH (physical uplink shared channel). [Figure 13]This figure shows the scheduling for PUSCH and PUCCH (physical uplink control channel). [Figure 14] This diagram shows the scheduling of PDSCH using multiple slot scheduling. [Figure 15] This diagram shows PUCCH transmission using one slot through multiple slot scheduling. [Figure 16] This diagram shows PUCCH transmission using two or more slots through multiple slot scheduling. [Figure 17] This diagram illustrates an existing Type-1 HARQ-ACK (hybrid automatic repeat request acknowledgement) codebook generation method. [Figure 18] This diagram shows the PDSCH candidates corresponding to HARQ-ACK when a PUCCH is sent in slot n.

[0038] [Figure 19] This figure shows an example of a HARQ-ACK opportunity according to the present invention. [Figure 20] This figure illustrates an example of the HARQ-ACK codebook generation process according to one example of the present invention. [Figure 21] This diagram shows the time domain bundling window. [Figure 22] This figure shows a representative PDSCH using a time-domain bundling window. [Figure 23] This figure shows HARQ-ACK opportunities due to the time-domain bundling window. [Figure 24] This figure illustrates an example of the HARQ-ACK transmission process according to the present invention. [Figure 25] This is a block diagram showing the configuration of a terminal and a base station according to one embodiment of the present invention. [Modes for carrying out the invention]

[0039] The terminology used herein has been selected to be as widely used and general as possible, taking into account the function of the present invention; however, this may vary depending on the intentions, conventions, or emergence of new technologies of the articulate. In some cases, the applicant has arbitrarily selected certain terms, in which case their meaning will be described in the relevant section of the invention description. Therefore, it should be made clear that the terminology used herein should not be merely names of terms, but should be analyzed based on the substantive meaning of the terms and the overall content of this specification.

[0040] Throughout the specification, when one configuration is said to be “connected” to another, this includes not only cases where they are “directly connected,” but also cases where they are “electrically connected” through other intermediate components. Furthermore, when a configuration is said to “include” a particular component, this means, unless otherwise stated, that it includes other components rather than excluding them. In addition, the limitations of “greater than” or “less than” a particular critical point may be appropriately replaced by “greater than” or “less than” depending on the embodiment.

[0041] The following technologies are used in a variety of wireless connectivity systems, including 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 is implemented using radio technology such as UTRA (Universal Terrestrial Radio Access) and CDMA2000. TDMA is implemented using radio technology such as GSM (Global System for Mobile communications) / GPRS (General Packet Radio Service) / EDGE (Enhanced Data Rates for GSM Evolution). OFDMA is implemented using radio technology such as IEEE802.11 (Wi-Fi), IEEE802.16 (WiMAX), IEEE802-20, and E-UTRA (Evolved UTRA). UTRA is part of UMTS (Universal Mobile Telecommunication System). 3GPP LTE (Long term evolution) is part of E-UMTS (Evolved UMTS) which uses E-UTRA, and LTE-A (Advanced) is an advanced version of 3GPP LTE. 3GPP NR is a system designed separately from LTE / LTE-A, and is intended to support eMBB (enhanced Mobile Broadband), URLLC (Ultra-Reliable and Low Latency Communication), and mMTC (massive Machine Type Communication) services, which are requirements of IMT-2020. While this explanation will focus on 3GPP NR for clarity, the technical concept of this invention is not limited to this.

[0042] Unless otherwise specified herein, a base station may include a gNB (next generation node B) as defined in 3GPP NR. Also, unless otherwise specified, a terminal may include a UE (user equipment). To aid understanding the explanation below, each concept will be described in separate embodiments, although these embodiments may be used in combination with each other. In this disclosure, terminal configuration may mean configuration by the base station. Specifically, the base station may transmit channels or signals to the terminal to configure the operation of the terminal or the values ​​of parameters used in the wireless communication system.

[0043] Figure 1 shows an example of a wireless frame structure used in a wireless communication system.

[0044] Referring to Figure 1, a radio frame (or radio frame) used in a 3GPP NR system has a length of 10 ms (ΔfmaxNf / 100) * Tc). A radio frame consists of 10 subframes (SF) of equal size, where Δfmax = 480 * 10³ Hz, Nf = 4096, Tc = 1 / (Δfref * Nf,ref), Δfref = 15 * 10³ Hz, and Nf,ref = 2048. Each of the 10 subframes within a single frame is assigned a number from 0 to 9. Each subframe has a length of 1 ms and consists of one or more slots determined by the subcarrier spacing. More specifically, the subcarrier spacing usable in a 3GPP NR system is 15 * 2 μkHz, where μ is the subcarrier spacing configuration, with values ​​from 0 to 4. In other words, 15kHz, 30kHz, 60kHz, 120kHz, or 240kHz are used as subcarrier intervals. A 1ms subframe consists of 2μm slots, each with a length of 2-μms. The 2μm slots within a subframe are each assigned numbers from 0 to 2μ-1. Similarly, the slots within a radio frame are each assigned numbers from 0 to 10*2μ-1. Time resources are divided by at least one of the following: radio frame number (also called radio frame index), subframe number (also called subframe index), or slot number (or slot index).

[0045] Figure 2 shows an example of a downlink (DL) / uplink (UL) slot structure in a wireless communication system. In particular, Figure 2 shows the resource grid structure of a 3GPP NR system.

[0046] There is one resource grid per antenna port. Referring to Figure 2, a slot contains multiple OFDM symbols in the time domain and multiple resource blocks (RBs) in the frequency domain. An OFDM symbol also means a single symbol interval. Unless otherwise specified, OFDM symbols are simply referred to as symbols. Hereafter, in this specification, symbols include OFDM symbols, SC-FDMA symbols, DFTs-OFDM symbols, etc. Referring to Figure 2, the signal transmitted from each slot is represented by a resource grid consisting of Nsize, μgrid, x*NRBSC subcarriers and Nslotsymb OFDM symbols. Here, x=DL for a downlink resource grid and x=UL for an uplink resource grid. Nsize, μgrid, and x indicate the number of resource blocks (RBs) with a subcarrier spacing component μ (x is DL or UL), and Nslotsymb indicates the number of OFDM symbols in the slot. NRBSC is the number of subcarriers constituting one RB, where NRBSC=12. OFDM symbols are also known as CP-OFDM (cyclic prefix OFDM) symbols or DFT-S-OFDM (discrete Fourier transform spread OFDM) symbols, depending on the multiple access method.

[0047] The number of OFDM symbols in a single slot can vary depending on the length of the cyclic prefix (CP). For example, a normal CP may contain 14 OFDM symbols in a single slot, while an extended CP may contain 12 OFDM symbols. In specific embodiments, extended CPs are used only with a subcarrier interval of 60 kHz. For the sake of explanation, Figure 2 illustrates a case where a single slot consists of 14 OFDM symbols, but the embodiments of the present invention are applied in the same manner to slots with other numbers of OFDM symbols. Referring to Figure 2, each OFDM symbol contains N size, μgrid, and x*NRBSC subcarriers in the frequency domain. Subcarrier types are divided into data subcarriers for transmitting data, reference signal subcarriers for transmitting reference signals, and guard bands. The carrier frequency is also called the center frequency (fc).

[0048] A single RB is defined by NRBSC (e.g., 12) consecutive subcarriers in the frequency domain. Incidentally, a resource consisting of one OFDM symbol and one subcarrier is called a resource element (RE) or tone. Therefore, a single RB consists of Nslotsymb*NRBSC resource elements. Each resource element in the resource grid is uniquely defined by an index pair (k, l) in a single slot. k is an index given in the frequency domain from 0 to Nsize, μgrid, and x*NRBSC-1, and l is an index given in the time domain from 0 to Nslotsymb-1.

[0049] For a terminal to receive signals from a base station or transmit base station signals, the terminal's time / frequency synchronization must be synchronized with the base station's time / frequency synchronization. If the base station and the terminal are not synchronized, the terminal cannot determine the time and frequency parameters necessary to demodulate DL signals and transmit UL signals at the correct time.

[0050] Each symbol in a radio frame operating in TDD (time division duplex) or unpaired spectrum consists of at least one of the following: a downlink symbol (DL symbol), an uplink symbol (UL symbol), or a flexible symbol. In FDD (frequency division duplex) or paired spectrum, a radio frame operating on a downlink carrier consists of either a downlink symbol or a flexible symbol, while a radio frame operating on an uplink carrier consists of either an uplink symbol or a flexible symbol. Downlink symbols can be used for downlink transmission but not uplink transmission, and uplink symbols can be used for uplink transmission but not downlink transmission. The use of a flexible symbol in the downlink or uplink is determined by the signal.

[0051] Information regarding the type of each symbol, i.e., whether it is a downlink symbol, uplink symbol, or flexible symbol, consists of a cell-specific (or common) RRC signal. Additionally, information regarding the type of each symbol consists of a UE-specific (or dedicated) RRC signal. The base station uses the cell-specific RRC signal to indicate: i) the period of the cell-specific slot configuration; ii) the number of slots containing only downlink symbols from the beginning of the cell-specific slot configuration period; iii) the number of downlink symbols from the first symbol in the slot immediately following the downlink-only slot; iv) the number of slots containing only uplink symbols from the end of the cell-specific slot configuration period; and v) the number of uplink symbols from the last symbol in the slot immediately preceding the uplink-only slot. Here, a symbol that is neither an uplink nor a downlink symbol is a flexible symbol.

[0052] If the information regarding the symbol type consists of the per-terminal RRC signal, the base station signals whether the flexible symbol is a downlink symbol or an uplink symbol via the cell-specific RRC signal. At this time, the per-terminal RRC signal cannot change the downlink symbol or uplink symbol consisting of the cell-specific RRC signal to another symbol type. The per-terminal RRC signal signals, for each slot, the number of downlink symbols among the Nslotsymb symbols of the slot and the number of uplink symbols among the Nslotsymb symbols of the slot. At this time, the downlink symbols of the slot are continuously configured from the first symbol to the i-th symbol of the slot. Also, the uplink symbols of the slot are continuously configured from the j-th symbol to the last symbol of the slot (where i < j). In a slot, a symbol not configured as either an uplink symbol or a downlink symbol is a flexible symbol.

[0053] The type of symbol configured by the RRC signal as described above can be called a semi-static DL / UL configuration. In the semi-static DL / UL configuration configured by the RRC signal previously, the flexible symbol may be indicated as a downlink symbol, an uplink symbol, or a flexible symbol by the dynamic SFI (slot format information) transmitted on the physical downlink control channel (PDCCH). At this time, the downlink symbol or uplink symbol configured by the RRC signal is not changed to another symbol type. Table 1 exemplifies the dynamic SFI that the base station can indicate to the terminal.

[0054]

Table 1

[0055] In Table 1, D represents the downlink symbol, U represents the uplink symbol, and X represents the flexible symbol. As shown in Table 1, a maximum of two DL / UL switching operations may be permitted within a single slot.

[0056] Figure 3 illustrates the physical channels used in 3GPP systems (e.g., NR) and a typical signal transmission method utilizing those physical channels.

[0057] When the terminal is powered on or enters a new cell, the terminal performs the initial cell discovery process (S101). Specifically, the terminal synchronizes with the base station during the initial cell discovery. To do this, the terminal receives a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) from the base station to synchronize with the base station and acquire information such as the cell index. Next, the terminal receives the physical broadcast channel from the base station and acquires broadcast information within the cell.

[0058] S102 A terminal that has completed the initial cell search receives a physical downlink shared channel (PDSCH) via the physical downlink control channel (PDCCH) and the information carried on the PDCCH, thereby obtaining more detailed system information than the system information obtained through the initial cell search.

[0059] When a terminal first connects to a base station, or when there are no radio resources for signal transmission (when the terminal is in RRC_IDLE mode), the terminal can perform a random access process to the base station (steps S103 to S106). First, the terminal transmits a preamble on the physical random access channel (PRACH) (S103), and can receive a response message for the preamble from the base station on the PDCCH and the corresponding PDSCH (S104). If the terminal receives a valid random access response message, the terminal transmits data including its identifier to the base station on the physical uplink shared channel (PUSCH) indicated by the uplink grant transmitted from the base station via the PDCCH (S105). Next, the terminal waits to receive a PDCCH as an instruction from the base station for collision resolution. When the terminal successfully receives a PDCCH with its identifier (S106), the random access process ends.

[0060] After the above procedure, the terminal receives PDCCH / PDSCH S107 and transmits the physical uplink sharing channel (PUSCH) / physical uplink control channel (PUCCH) S108 as a general uplink / downlink signal transmission procedure. In particular, the terminal receives downlink control information (DCI) via PDCCH. DCI includes control information such as resource allocation information for the terminal. Also, the format of DCI may differ depending on its intended use. Uplink control information (UCI) that the terminal transmits to the base station via the uplink includes downlink / uplink ACK / NACK signals, CQI (channel quality indicator), PMI (precoding matrix index), RI (rank indicator), etc. Here, CQI, PMI, and RI are included in CSI (channel state information). In the case of a 3GPP NR system, the terminal transmits the above-mentioned HARQ-ACK and control information such as CSI using PUSCH and / or PUCCH.

[0061] Figure 4 shows the SS / PBCH block for initial cell access in a 3GPP NR system.

[0062] When a terminal is powered on or attempts to access a new cell, it acquires time and frequency synchronization with the cell and performs an initial cell discovery process. During the cell discovery process, the terminal detects the cell's physical cell identity (NcellID). To do this, the terminal receives synchronization signals from the base station, such as the primary synchronization signal (PSS) and secondary synchronization signal (SSS), to synchronize with the base station. At this time, the terminal obtains information such as the cell identifier (identity, ID).

[0063] Refer to Figure 4(a) for a more detailed explanation of the synchronization signal (SS). The synchronization signal is divided into PSS and SSS. PSS is used to obtain time-domain synchronization and / or frequency-domain synchronization, such as OFDM symbol synchronization and slot synchronization. SSS is used to obtain frame synchronization and cell group ID. Referring to Figure 4(a) and Table 1, an SS / PBCH block consists of 20 RBs (=240 subcarriers) consecutively on the frequency axis and 4 OFDM symbols consecutively on the time axis. In this case, within the SS / PBCH block, the PSS is transmitted via the first OFDM symbol and the SSS via the second subcarrier (56-18) for the third OFDM symbol. Here, the lowest subcarrier index of the SS / PBCH block is assigned starting from 0. In the first OFDM symbol on which the PSS is transmitted, the base station does not transmit signals via the remaining subcarriers, i.e., subcarriers 0-55 and 183-239. Furthermore, in the third OFDM symbol on which SSS is transmitted, the base station does not transmit signals via subcarriers 48-55 and 183-19. In the SS / PBCH block, the base station transmits PBCH (physical broadcast channel) via the remaining REs excluding the aforementioned signals.

[0064] [Table 2]

[0065] The SS generates a total of 1008 unique physical layer cell IDs through combinations of three PSSs and SSSs. More specifically, each physical layer cell ID is part of only one physical layer cell identifier group, and each group is grouped into 336 physical layer cell identifier groups, each containing three unique identifiers. Therefore, the physical layer cell ID NcellID = 3N(1)ID + N(2)ID is uniquely defined by an index N(1)ID ranging from 0 to 335 that represents a physical layer cell identifier group, and an index N(2)ID ranging from 0 to 2 that represents a physical layer identifier within the physical layer cell identifier group. The terminal detects the PSS and identifies one of the three unique physical layer identifiers. The terminal also detects the SSS and identifies one of the 336 physical layer cell IDs associated with the physical layer identifier. In this case, the PSS sequence dPSS(n) is as shown in Equation 1 below.

[0066] d PSS (n) = 1 - 2x(m) m=(n+43N (2) ID ) mod 127 0 ≤ n < 127

[0067] Here, x(i+7)=(x(i+4)+x(i)) mod 2,

[0068] [x(6)x(5)x(4)x(3)x(2)x(1)x(0)]=[1110110] is given.

[0069] Furthermore, the SSS sequence dSSS(n) is as follows:

[0070] d SSS (n)=[1-2x0((n+m0) mod 127][1-2x1((n+m1) mod 127] m0 = 15 floor(N (1) ID / 112)+5N (2) ID m1=N (1) ID mod 112 0 ≤ n < 127

[0071] Here, x0(i+7)=(x0(i+4)+x0(i))mod 2 x1(i+7)=(x1(i+1)+x1(i))mod 2,

[0072] [x0(6)x0(5)x0(4)x0(3)x0(2)x0(1) 0(0)]=[0000001] and [x1(6)x1(5)x1(4)x1(3)x1(2)x1(1)x1(0)]=[0000001] are given.

[0073] A 10ms long wireless frame is divided into two 5ms long half-frames. Refer to Figure 4(b) to describe the slot in which an SS / PBCH block is transmitted within each half-frame. The slot in which an SS / PBCH block is transmitted is one of cases A, B, C, D, or E. In case A, the subcarrier interval is 15kHz, and the start of the SS / PBCH block is at the {2, 8} + 14*n symbol. In this case, n=0, 1 for carrier frequencies below 3GHz. Also, n=0, 1, 2, 3 for carrier frequencies above 3GHz and below 6GHz. In case B, the subcarrier interval is 30kHz, and the start of the SS / PBCH block is at the {4, 8, 16, 20} + 28*n symbol. In this case, n=0 for carrier frequencies below 3GHz. Also, n=0, 1 for carrier frequencies above 3GHz and below 6GHz. In Case C, the subcarrier spacing is 30 kHz, and the SS / PBCH block starts at the {2nd, 8th} + 14*nth symbol. In this case, for carrier frequencies below 3 GHz, n=0, 1. Also, for carrier frequencies above 3 GHz and below 6 GHz, n=0, 1, 2, 3. In Case D, the subcarrier spacing is 120 kHz, and the SS / PBCH block starts at the {4th, 8th, 16th, 20th} + 28*nth symbol. In this case, for carrier frequencies above 6 GHz, n=0, 1, 2, 3, 5, 6, 7, 8, 10, 11, 12, 13, 15, 16, 17, 18. In Case E, the subcarrier spacing is 240 kHz, and the SS / PBCH block starts at the {8th, 12th, 16th, 20th, 32nd, 36th, 40th, 44th} + 56*nth symbol. In this case, at carrier frequencies of 6 GHz or higher, n = 0, 1, 2, 3, 5, 6, 7, 8.

[0074] Figure 5 shows the procedure for transmitting control information and control channels in a 3GPP NR system. Referring to Figure 5(a), the base station adds a CRC (cyclic redundancy check) masked (e.g., by XOR operation) with an RNTI (radio network temporary identifier) ​​to the control information (e.g., DCI) S202. The base station scrambles the CRC with an RNTI value determined according to the purpose / target of each piece of control information. A common RNTI used by one or more terminals includes at least one of the following: SI-RNTI (system information RNTI), P-RNTI (paging RNTI), RA-RNTI (random access RNTI), and TPC-RNTI (transmit power control RNTI). Furthermore, the terminal-specific RNTI includes at least one of the following: C-RNTI (cell temporary RNTI), CS-RNTI, or MCS-C-RNTI. Next, after the base station performs channel encoding (e.g., polar coding) in S204, it performs rate-matching in S206 to match the amount of resources used for PDCCH transmission. Next, the base station multiplexes the DCIs (data elements) based on the CCE (control channel element)-based PDCCH structure in S208. The base station also applies additional processes S210 to the multiplexed DCIs (data elements), such as scrambling, modulation (e.g., QPSK), and interleaving, before mapping them to the resources to be transmitted. A CCE is the basic resource unit for PDCCH, and one CCE consists of multiple (e.g., 6) REGs (resource element groups). One REG consists of multiple (e.g., 12) REs. The number of CCEs used for one PDCCH is defined as the aggregation level. The 3GPP NR system uses 1, 2, 4, 8, or 16 integrated levels.Figure 5(b) is a diagram relating to the CCE integration level and PDCCH multiplexing, showing the types of CCE integration levels used for a single PDCCH and the CCEs transmitted in the control domain as a result.

[0075] Figure 6 shows the CORESET to which PDCCH is transmitted in a 3GPP NR system.

[0076] A CORESET is a time-frequency resource on which PDCCH, a control signal for a terminal, is transmitted. Furthermore, the search space, described later, is mapped to a single CORESET. Therefore, instead of monitoring the entire frequency band to receive PDCCH, the terminal monitors the CORESET and the designated time-frequency domain to decode the PDCCH mapped to the CORESET. A base station configures one or more CORESETs for each cell in the terminal. A CORESET consists of up to three consecutive symbols on the time axis. A CORESET also consists of six consecutive PRB units on the frequency axis. In the embodiment shown in Figure 5, CORESET#1 consists of consecutive PRBs, while CORESET#2 and CORESET#3 consist of discontinuous PRBs. A CORESET can be located at any symbol within a slot. For example, in the embodiment shown in Figure 5, CORESET#1 starts at the first symbol of the slot, CORESET#2 starts at the fifth symbol of the slot, and CORESET#9 starts at the ninth symbol of the slot.

[0077] Figure 7 shows how to configure the PDCCH search space in a 3GPP NR system.

[0078] To transmit a PDCCH to a terminal, each CORESET has at least one search space. In embodiments of the present invention, the search space is a collection of all time-frequency resources (hereinafter referred to as PDCCH candidates) from which the terminal's PDCCH is transmitted. The search space includes a common search space that all 3GPP NR terminals should search in common, and a terminal-specific or UE-specific search space that a specific terminal should search. In the common search space, all terminals in a cell belonging to the same base station monitor the PDCCH that they are set to search in common. The terminal-specific search spaces are configured terminal-specific to monitor the PDCCH assigned to each terminal at different locations in the search space depending on the terminal. In the case of terminal-specific search spaces, the search spaces between terminals may partially overlap due to the limited control area to which the PDCCH is assigned. Monitoring a PDCCH includes blind decoding of PDCCH candidates in the search space. If blind decoding is successful, it is expressed as the PDCCH being (successfully) detected / received. If blind decoding fails, it is expressed as the PDCCH not being detected / received, or not being successfully detected / received.

[0079] For the sake of explanation, a PDCCH scrambled with a group common (GC) RNTI already known by one or more terminals, in order to transmit downlink control information to one or more terminals, is referred to as a group common (GC) PDCCH or common PDCCH. Furthermore, a PDCCH scrambled with a terminal-specific RNTI already known by a specific terminal, in order to transmit uplink scheduling information or downlink scheduling information to a specific terminal, is referred to as a terminal-specific PDCCH. The common PDCCH is included in the common search space, and the terminal-specific PDCCH is included in either the common search space or the terminal-specific PDCCH.

[0080] The base station uses PDCCH to inform each terminal or group of terminals of information regarding resource allocation for the transmission channels PCH (paging channel) and DL-SCH (downlink-shared channel) (i.e., DL Grant), or information regarding resource allocation for UL-SCH and HARQ (hybrid automatic repeat request) (i.e., UL Grant). The base station transmits PCH transmission blocks and DL-SCH transmission blocks via PDSCH. The base station transmits data excluding specific control information or specific service data via PDSCH. The terminal also receives data excluding specific control information or specific service data via PDSCH.

[0081] The base station transmits a PDCCH containing information about which terminals (one or more terminals) the PDSCH data will be sent to and how those terminals should receive and decode the PDSCH data. For example, suppose a DCI transmitted in a particular PDCCH is CRC masked with an RNTI named "A", and that DCI indicates that the PDSCH is assigned to a radio resource (e.g., frequency location) named "B", and indicates transmission format information (e.g., transmission block size, modulation scheme, coding information, etc.) named "C". Terminals monitor the PDCCH using their own RNTI information. In this case, if a terminal blind-decodes the PDCCH using the "A" RNTI, that terminal will receive the PDCCH and, through the information of the received PDCCH, receive the PDSCH indicated by "B" and "C".

[0082] Table 3 shows one example of PUCCH used in a wireless communication system.

[0083] [Table 3]

[0084] PUCCH is used to transmit the following Uplink Control Information (UCI):

[0085] - SR (Scheduling Request): This is information used to request uplink UL-SCH resources.

[0086] - HARQ-ACK: A response to a PDCCH and / or an uplink transmission block (TB) on a PDSCH (indicating a DL SPS (semi-persistent scheduling) release). HARQ-ACK indicates whether information transmitted on the PDCCH or PDSCH has been received. HARQ-ACK responses include positive ACK (simply ACK), negative ACK (hereinafter NACK), DTX (Discontinuous Transmission), or NACK / DTX. Here, the term HARQ-ACK is used interchangeably with HARQ-ACK / NACK and ACK / NACK. Generally, ACK is represented by a bit value of 1 and NACK is represented by a bit value of 0.

[0087] - CSI: Feedback information for the downlink channel. It is generated by the terminal based on the CSI-RS (Reference Signal) transmitted by the base station. MIMO (multiple input multiple output) related feedback information includes RI and PMI. CSI is divided into CSI Part 1 and CSI Part 2 depending on the information it indicates.

[0088] The 3GPP NR system uses five PUCCH formats to support diverse service scenarios, diverse channel environments, and frame structures.

[0089] PUCCH format 0 is a format for transmitting 1-bit or 2-bit HARQ-ACK information or SR. PUCCH format 0 is transmitted via one or two OFDM symbols on the time axis and one RB on the frequency axis. If PUCCH format 0 is transmitted with two OFDM symbols, the same sequence is transmitted for each symbol with different RBs. Through this, the terminal obtains a frequency diversity gain. More specifically, the terminal determines the cyclic shift value mcs according to the Mbit bit UCI (Mbit=1 or 2), and maps a sequence obtained by cyclic shifting a base sequence of length 12 by the determined value mcs to 12 REs (Res) consisting of one OFDM symbol and one PRB, and transmits it. If the number of cyclic shifts available to the terminal is 12 and Mbit=1, then 1-bit UCI0 and 1 are represented by sequences corresponding to two cyclic shifts with a cyclic shift value difference of 6. Furthermore, if Mbit=2, the 2-bit UCI00, 01, 11, and 10 represent a sequence of four cyclic shifts where the difference in cyclic shift values ​​is 3.

[0090] PUCCH format 1 transmits 1-bit or 2-bit HARQ-ACK information or SR. PUCCH format 1 is transmitted via a continuous sequence of OFDM symbols on the time axis and one PRB on the frequency axis. Here, the number of OFDM symbols occupied by PUCCH format 1 is one of 4 to 14. More specifically, a UCI with Mbit=1 is modulated with BPSK. The terminal modulates a UCI with Mbit=2 with QPSK (quadrature phase shift keying). A signal is obtained by multiplying the modulated complex valued symbol d(0) by a sequence of length 12. The terminal spreads the obtained signal with a time-axis OCC (orthogonal cover code) to the even-numbered OFDM symbols assigned to PUCCH format 1 and transmits it. The maximum number of different terminals multiplexed on the same RB in PUCCH format 1 is determined by the length of the OCC used. For odd-numbered OFDM symbols in PUCCH format 1, the DMRS (demodulation reference signal) is spread across the OCC and mapped to them.

[0091] PUCCH format 2 transmits UCI exceeding 2 bits. PUCCH format 2 is transmitted via one or two OFDM symbols on the time axis and one or more RBs on the frequency axis. If PUCCH format 2 is transmitted via two OFDM symbols, the same sequence is transmitted via the two OFDM symbols with different RBs. Through this, the terminal gains frequency diversity gain. More specifically, an Mbit bit UCI (Mbit > 2) is bit-level scrambled and QPSK modulated and mapped to the RBs of one or two OFDM symbols, where the number of RBs is one between 1 and 16.

[0092] PUCCH format 3 or PUCCH format 4 transmits UCI exceeding 2 bits. PUCCH format 3 or PUCCH format 4 is transmitted via continuous OFDM symbols on the time axis and one PRB on the frequency axis. The number of OFDM symbols occupied by PUCCH format 3 or PUCCH format 4 is one of 4 to 14. Specifically, the terminal modulates an Mbit bit UCI (Mbit>2) with π / 2-BPSK (Binary Phase Shift Keying) or QPSK to generate complex number symbols d(0) to d(Msymb-1). Here, with π / 2-BPSK, Msymb = Mbit, and with QPSK, Msymb = Mbit / 2. The terminal does not apply block-unit spreading to PUCCH format 3. However, the terminal may apply block-unit spreading to one RB (i.e., 12 subcarriers) using a PreDFT-OCC of length -12 so that the PUCCH format 4 has two or four multiplexing capacities. The terminal transmits the spread signal using transmit precoding (or DFT-precoding) and maps it to each RE to transmit the spread signal.

[0093] In this case, the number of RBs occupied by PUCCH format 2, PUCCH format 3, or PUCCH format 4 is determined according to the length of the UCI transmitted by the terminal and the maximum code rate. If the terminal uses PUCCH format 2, it transmits both HARQ-ACK information and CSI information using PUCCH. If the number of RBs required for UCI transmission is greater than the maximum number of RBs available for PUCCH format 2, PUCCH format 3, or PUCCH format 4, the terminal will not transmit some of the UCI information according to the priority of the UCI information, and will transmit only the remaining UCI information.

[0094] PUCCH format 1, PUCCH format 3, or PUCCH format 4 is configured via an RRC signal to instruct frequency hopping within a slot. When frequency hopping is configured, the index of the RB to be frequency-hopped is determined by the RRC signal. If PUCCH format 1, PUCCH format 3, or PUCCH format 4 is transmitted over N OFDM symbols in the time axis, the first hop will have floor(N / 2) OFDM symbols, the second hop will have ceil(N / 2) OFDM symbols.

[0095] PUCCH format 1, PUCCH format 3, or PUCCH format 4 are configured to be repeatedly transmitted to multiple slots. In this case, the number K of slots to which the PUCCH is repeatedly transmitted is determined by the RRC signal. The repeatedly transmitted PUCCH should start from the same OFDM symbol in the same position within each slot and have the same length. If any of the OFDM symbols in a slot to which the terminal is to transmit the PUCCH is indicated as a DL symbol by the RRC signal, the terminal does not transmit the PUCCH from that slot but postpones transmission to the next slot.

[0096] On the other hand, in the 3GPP NR system, terminals transmit and receive using a bandwidth smaller than or equal to the carrier (or cell) bandwidth. For this purpose, terminals are configured with a bandwidth part (BWP) consisting of a contiguous portion of the carrier bandwidth. Terminals operating according to TDD or in the ampered spectrum have up to four DL / UL BWP pairs per carrier (or cell). The terminal also activates one DL / UL BWP pair. Terminals operating according to FDD or in the paired spectrum have up to four DL BWPs configured on the downlink carrier (or cell) and up to four UL BWPs configured on the uplink carrier (or cell). The terminal activates one DL BWP and one UL BWP per carrier (or cell). The terminal does not have to receive or transmit from time-frequency resources other than the activated BWPs. The activated BWPs are called active BWPs.

[0097] The base station refers to the activated BWP among the configured BWPs of a terminal as the DCI. The BWP indicated by the DCI is activated, and the other configured BWPs are deactivated. In a carrier (or cell) operating in TDD mode, the base station includes a BPI (bandwidth part indicator) in the DCI that schedules the PDSCH or PUSCH to indicate which BWP to activate in order to change the terminal's DL / UL BWP pair. The terminal receives the DCI that schedules the PDSCH or PUSCH and identifies the DL / UL BWP pair to activate based on the BPI. In the case of a downlink carrier (or cell) operating in FDD mode, the base station includes a BPI informing the DCI that schedules the PDSCH which BWP to activate in order to change the terminal's DL BWP. In the case of an uplink carrier (or cell) operating in FDD mode, the base station includes a BPI informing the DCI that schedules the PUSCH which BWP to activate in order to change the terminal's UL BWP.

[0098] Figure 8 is a conceptual diagram illustrating career integration.

[0099] Carrier aggregation refers to a method used by wireless communication systems to utilize a wider frequency band by having terminals use multiple frequency blocks, or (logical) cells, consisting of uplink resources (or component carriers) and / or downlink resources (or component carriers), within a single larger logical frequency band. For convenience of explanation, the term "component carrier" will be used consistently below.

[0100] Referring to Figure 8, as an example of a 3GPP NR system, the overall system bandwidth includes up to 16 component carriers, each component carrier having a bandwidth of up to 400 MHz. Each component carrier includes one or more physically consecutive subcarriers. Although Figure 8 shows each component carrier having the same bandwidth, this is merely illustrative, and each component carrier may have different bandwidths. Also, although each component carrier is shown as being adjacent to each other on the frequency axis, the diagram is a logical representation, and each component carrier may be physically adjacent to or far from each other.

[0101] Each component carrier uses a different center frequency. Furthermore, physically adjacent component carriers share a single common center frequency. In the embodiment shown in Figure 8, assuming all component carriers are physically adjacent, center frequency A is used for all component carriers. If we assume that the component carriers are not physically adjacent, then center frequencies A and B are used for each component carrier.

[0102] When the overall system bandwidth is expanded through carrier aggregation, the frequency band used for communication with each terminal is defined on a component carrier basis. Terminal A uses the overall system bandwidth of 100 MHz and communicates using all five component carriers. Terminals B1 to B5 use only a 20 MHz bandwidth and communicate using one component carrier each. Terminals C1 and C2 use only a 40 MHz bandwidth and communicate using two component carriers each. The two component carriers may be logically / physically adjacent or not. In the embodiment shown in Figure 8, terminal C1 uses two non-adjacent component carriers, and terminal C2 uses two adjacent component carriers.

[0103] Figure 9 is a diagram illustrating terminal carrier communication and multiple carrier communication. Specifically, Figure 9(a) shows the subframe structure of a single carrier, and Figure 9(b) shows the subframe structure of a multiple carrier.

[0104] Referring to Figure 9(a), a typical wireless communication system, in FDD mode, transmits or receives data via one DL band and its corresponding UL band. In other specific embodiments, in TDD mode, the wireless communication system divides the wireless frame into uplink time units and downlink time units in the time domain, and transmits or receives data via the uplink / downlink time units. Referring to Figure 9(b), three 20MHz component carriers (CCs) are aggregated in both the UL and DL bands, supporting a 60MHz bandwidth. Each CC is either adjacent or non-adjacent to the others in the frequency domain. For convenience, Figure 9(b) shows a symmetrical case where the bandwidths of the UL CCs and DL CCs are the same, but the bandwidths of each CC may be determined independently. Asymmetric carrier aggregations with different numbers of UL CCs and DL CCs are also possible. A DL / UL CC assigned / configured to a specific terminal via RRC is referred to as the serving DL / UL CC of that terminal.

[0105] A base station communicates with a terminal by activating some or all of the terminal's serving CCs, or by deactivating some of the CCs. The base station may change which CCs are activated / deactivated, or change the number of CCs that are activated / deactivated. Once a base station assigns available CCs to a terminal, either cell-specific or terminal-specific, at least one of the initially assigned CCs does not need to be deactivated unless the CC assignments for the terminal are completely reconfigured or the terminal is handed over. The CC that is not deactivated by the terminal is called the primary CC (PCC) or PCell (primary cell), and the CCs that the base station can freely activate / deactivate are called secondary CCs (SCC) or SCell (secondary cell).

[0106] On the other hand, 3GPP NR uses the concept of a cell to manage radio resources. A cell is defined as a combination of downlink and uplink resources, i.e., a combination of DL CC and UL CC. A cell consists of DL resources alone, or a combination of DL and UL resources. If carrier aggregation is supported, the linkage between the carrier frequency of the DL resource (or DL ​​CC) and the carrier frequency of the UL resource (or UL CC) is indicated by system information. Carrier frequency refers to the center frequency of each cell or CC. A cell corresponding to a PCC is called a PCell, and a cell corresponding to an SCC is called a SCell. In the downlink, the carrier corresponding to a PCell is a DL PCC, and in the uplink, the carrier corresponding to a PCell is a UL PCC. Similarly, in the downlink, the carrier corresponding to a SCell is a DL SCC, and in the uplink, the carrier corresponding to a SCell is a UL SCC. Depending on the terminal capacity, a serving cell consists of one PCell and zero or more SCells. If the RRC_CONNECTED state exists but carrier aggregation is not configured, or if the UE does not support carrier aggregation, there will be only one serving cell consisting solely of PCells.

[0107] As described above, the term "cell" used in carrier aggregation is distinct from the term "cell" which refers to a specific geographical area where communication services are provided by a single base station or antenna group. However, in order to distinguish between a cell referring to a specific geographical area and a cell in carrier aggregation, in this invention, a cell in carrier aggregation is referred to as CC, and a cell referring to a geographical area is referred to as cell.

[0108] Figure 10 shows an example where the cross-carrier scheduling technique is applied. Once cross-carrier scheduling is set up, the control channel transmitted via the first CC uses the carrier indicator field (CIF) to schedule the data channel transmitted via the first or second CC. The CIF is contained within the DCI. In other words, a scheduling cell is set up, and DL grants / UL grants transmitted from the PDCCH area of ​​the scheduling cell schedule the PDSCH / PUSCH of the scheduled cell. That is, the PDCCH area of ​​the scheduling cell is a search area for multiple component carriers. A PCell is essentially a scheduling cell, and a particular SCell is designated as a scheduling cell by a higher hierarchy.

[0109] In the embodiment shown in Figure 10, we assume that three DL CCs are merged. Here, we assume that DL component carrier #0 is DL PCC (or PCell), and DL component carriers #1 and #2 are DL SCC (or SCell). We also assume that DL PCC is configured as a PDCCH monitoring CC. If cross-carrier scheduling is not configured by terminal-specific (or terminal-group-specific, or cell-specific) higher-level signaling, the CIF is disabled, and each DL CC transmits only PDCCHs that schedule its own PDSCH without a CIF, according to the NR PDCCH rule (non-cross-carrier scheduling, self-carrier scheduling). On the other hand, if cross-carrier scheduling is configured by terminal-specific (or terminal-group-specific, or cell-specific) higher-level signaling, the CIF is enabled, and a specific CC (e.g., DL PCC) uses the CIF to transmit not only PDCCHs that schedule the PDSCH of DL CC A, but also PDCCHs that schedule the PDSCH of other CCs (cross-carrier scheduling). In contrast, PDCCH is not transmitted in other DL CCs. Therefore, depending on whether cross-carrier scheduling is configured on the terminal, the terminal either monitors a PDCCH without a CIF and receives a self-carrier scheduled PDSCH, or monitors a PDCCH with a CIF and receives a cross-carrier scheduled PDSCH.

[0110] On the other hand, Figures 9 and 10 illustrate the subframe structure of a 3GPP LTE-A system, and the same or similar configurations are also applicable to a 3GPP NR system. However, in a 3GPP NR system, the subframes in Figures 9 and 10 may be replaced with slots.

[0111] Referring to Figures 11 and 12, the methods by which a terminal receives PDCCH / PDSCH and transmits PUCCH / PUSCH will be explained.

[0112] The terminal can receive the DCI format via PDCCH. The DCI format includes the following:

[0113] - DCI format 0_x (x=0,1,2): DCI format for scheduling push transmissions (hereinafter referred to as DL Grant (DG) DCI format, or DG DCI)

[0114] - DCI format 1_x (x=0,1,2): DCI format for scheduling PDSCH reception (hereinafter referred to as UL Grant (UG) DCI format, or UG DCI)

[0115] When a terminal receives a DCI format (i.e., DG DCI format) that schedules a PDSCH, the terminal can receive the PDSCH scheduled by the DG DCI format. To do this, the terminal can analyze (determine) from the DG DCI format i) the slot in which the PDSCH is scheduled and ii) the starting index / length of the symbol within the slot. The TDRA (time domain resource assignment) field of the DG DCI format can indicate (i) the K0 value, which is the timing information of the slot (e.g., slot offset), and (ii) the SLIV (starting length indicator value) value, which is the index / length of the starting symbol within the slot. Here, the K0 value may be a non-negative integer. SLIV may be a joint-encoded value of the index (S) / length (L) of the starting symbol within the slot. Alternatively, SLIV may be a value that is transmitted separately. For example, in a normal CP, S may have one value from 0, 1, ..., 13, and L may have one value from any natural number satisfying the condition that S + L is less than or equal to 14. In an extended CP, S may have one value from 0, 1, ..., 11, and L may have one value from any natural number satisfying the condition that S + L is less than or equal to 12.

[0116] The terminal can determine the slot on which the PDSCH is received based on the K0 value. Specifically, the terminal can determine the slot on which the PDSCH is received based on (i) the K0 value, (ii) the index of the slot on which the DG DCI was received, (iii) the SCS of the (DL)BWP on which the DG DCI was received (i.e., the SCS applied to the DG DCI), and (iv) the SCS of the (DL)BWP on which the PDSCH is received (i.e., the SCS applied to the PDSCH).

[0117] As an example, let's assume that (i) the BWP from which the DG DCI is received and (ii) the SCS of the BWP from which the PDSCH is received are the same. In this case, let's assume that the DG DCI is received in DL slot n. In this case, the PDSCH corresponding to the DG DCI is received in DL slot n+K0.

[0118] As another example, let's assume that the SCS of the BWP from which the DG DCI is received is 15kHz*2^mu_PDCCH, and the SCS of the BWP from which the PDSCH is received is also 15kHz*2^mu_PDSCH. Let's assume that the DG DCI is received in DL slot n. Here, the index of DL slot n is the index of the BWP from which the DG DCI was received based on its SCS. In this case, the PDSCH corresponding to the DG DCI is received in DL slot floor(n*2^mu_PDSCH / 2^mu_PDCCH)+K0. Here, the index of DL slot floor(n*2^mu_PDSCH / 2^mu_PDCCH)+K0 is the index of the BWP from which the PDSCH is received based on its SCS. mu_PDCCH and mu_PDSCH may have values ​​of 0, 1, 2, or 3, respectively.

[0119] Referring to Figure 11, let's assume that the terminal receives a PDCCH that schedules a PDSCH in DL slot n. Let's also assume that the DCI transmitted in the PDCCH indicates K0=3. Let's also assume that (i) the SCS of the DL BWP where the PDCCH is received (i.e., the SCS applied to the PDCCH; PDCCH SCS) and (ii) the SCS of the DL BWP where the PDSCH is scheduled (i.e., the SCS applied to the PDSCH; PDSCH SCS) are the same. In this case, the terminal can determine that a PDSCH is scheduled in DL slot n+K0, i.e., slot n+3.

[0120] The terminal can determine which symbol PDSCH is assigned to in the slot determined based on the K0 value, using the index (S) and length (L) of the starting symbol. The symbol PDSCH is assigned to is symbol S to symbol S+L-1 in the slot determined based on the K0 value. Here, symbol S to symbol S+L-1 are L consecutive symbols.

[0121] The terminal may have a DL slot aggregation set by the base station. The DL slot aggregation value may be 2, 4, or 8. Once the DL slot aggregation is set, the terminal can receive PDSCH in consecutive slots corresponding to the slot aggregation value, starting from the slot determined based on the K0 value.

[0122] When a terminal receives a DCI format (e.g., DG DCI format) that schedules a PUCCH, the terminal can send the scheduled PUCCH, which may include HARQ-ACK information. The PDSCH-to-HARQ_feedback timing indicator field included in the DG DCI format can indicate a K1 value for information about the slot in which the PUCCH is scheduled, where the K1 value may be a non-negative integer. The K1 value in DCI format 1_0 can indicate one of the values ​​{0, 1, 2, 3, 4, 5, 6, 7} (hereinafter referred to as the K1 set). The K1 values ​​in DCI formats 1_1 and 1_2 can indicate one of the values ​​(i.e., the K1 set) configured / set by the higher layer (e.g., RRC).

[0123] The HARQ-ACK information may consist of two types of HARQ-ACK information indicating whether or not the channel was successfully received. As a first type, when a PDSCH is scheduled by DCI format 1_x, the HARQ-ACK information may be a HARQ-ACK indicating whether or not the PDSCH was successfully received. As a second type, when DCI format 1_x is a DCI that instructs the release of an SPS PDSCH, the HARQ-ACK information may be a HARQ-ACK indicating whether or not the DCI formats 1_0, 1_1, and 1_2 were successfully received.

[0124] A terminal can determine the slot on which a PUCCH containing the first type of HARQ-ACK information is transmitted as follows: The terminal can determine (UL) slot #A that coincides with the last symbol of the PDSCH corresponding to the HARQ-ACK information. If the index of (UL) slot #A is m, then the index of (UL) slot #B on which the terminal transmits a PUCCH containing HARQ-ACK information may be m + K1. Here, the index of the (UL) slot is the value determined by the SCS of the UL BWP on which the PUCCH is transmitted (i.e., the SCS applied to the PUCCH; the SCS of the PUCCH). On the other hand, when a DL slot set is configured on the terminal, the last symbol of the PDSCH represents the last symbol of the PDSCH scheduled in the last slot on which the PDSCH is received.

[0125] Referring to Figure 12, let's assume that the terminal receives a PDCCH that schedules a PDSCH in DL slot n. Let's also assume that the DCI within the PDCCH indicates K0=3 and K1=2. Let's also assume that the SCS of the DL BWP where the PDCCH is received (i.e., the SCS of the PDCCH), the SCS of the DL BWP where the PDSCH is scheduled (i.e., the SCS of the PDSCH), and the SCS of the UL BWP where the PUCCH is transmitted (i.e., the SCS of the PUCCH) are the same. In this case, the terminal can determine that a PDSCH is scheduled in DL slot n+K0, i.e., slot n+3. The terminal can also determine the UL slot that coincides with the last symbol of the PDSCH scheduled in DL slot n+3. Here, the last symbol of the PDSCH in DL slot n+3 coincides with UL slot n+3. Therefore, the terminal can transmit a PUCCH in UL slot n+3+K1, i.e., slot n+5.

[0126] The terminal can determine the slot to transmit a PUCCH containing the second type of HARQ-ACK information as follows: The terminal can determine UL slot #A that coincides with the last symbol of the PDCCH corresponding to the HARQ-ACK information (e.g., the PDCCH transmitting the SPS release DCI). If the index of UL slot #A is m, then the index of UL slot #B to which the terminal transmits the PUCCH containing the HARQ-ACK information may be m+K1. Here, the index of the UL slot is the value determined by the SCS of the UL BWP to which the PUCCH is transmitted (i.e., the SCS of the PUCCH).

[0127] Referring to Figure 13, let's assume that the terminal receives a PDCCH transmitting an SPS PDSCH release DCI in DL slot n. Let's assume that the DCI transmitted in the PDCCH indicates K1=3. Let's also assume that the SCS of the DL BWP where the PDCCH is received and the SCS of the UL BWP where the PUCCH is transmitted are the same. In this case, the terminal can determine the UL slot n that coincides with the last symbol of the PDCCH in DL slot n. In this case, the terminal can determine that a PUCCH transmitting a HARQ-ACK for the SPS PDSCH release DCI is scheduled for UL slot n+K1, i.e., UL slot n+3.

[0128] When a terminal receives a DCI format (i.e., UG DCI format) that schedules a PUSCH, the terminal can send the scheduled PUSCH. To do this, the terminal must parse (determine) from the DCI (i) the slot in which the PUSCH is scheduled and (ii) the starting index and length of the symbol within the slot. The TDRA field of the UG DCI format can indicate (i) a K2 value for information about the scheduled slot, and (ii) a SLIV value for information about the index and length of the starting symbol within the slot. Here, the K2 value may be a non-negative integer. Here, SLIV may be a joint-encoded value of the index (S) and length (L) of the starting symbol within the slot. Alternatively, SLIV may be a value where the index (S) and length (L) of the starting symbol within the slot are sent separately. For example, in a regular CP, S may have one value from 0, 1, ..., 13, and L may have one value from natural numbers satisfying the condition that S + L is less than or equal to 14. In the extended CP, S may have one value from 0, 1, ..., 11, and L may have one value from natural numbers that satisfy the condition S + L is less than or equal to 12.

[0129] The terminal can determine which slot PUSCH is scheduled based on the K2 value. Specifically, based on the K2 value, the index of the slot where UG DCI is received, and the SCS of the DL BWP where UG DCI is received, or the SCS of the UL BWP that sends PUSCH, the terminal can determine which slot PUSCH should be sent to.

[0130] As an example, let's assume that (i) the DL BWP that received the UG DCI and (ii) the SCS of the UL BWP that sent the PUSCH are the same. Let's also assume that the UG DCI was received in DL slot n. In this case, the PUSCH can be sent in UL slot n+K2.

[0131] As another example, let's assume that the SCS of the DL BWP that received the UG DCI is 15kHz*2^mu_PDCCH, and the SCS of the UL BWP that sent the PUSCH is 15kHz*2^mu_PUSCH. Let's also assume that the UG DCI was received in DL slot n. Here, the index of DL slot n is the index of the DL BWP that received the UG DCI (i.e., the SCS of the UG DCI). In this case, the PUSCH may be transmitted in slot floor(n*2^mu_PUSCH / 2^mu_PDCCH)+K2. Here, the slot index floor(n*2^mu_PUSCH / 2^mu_PDCCH)+K2 is the index of the UL BWP that sent the PUSCH in terms of its SCS. Here, mu_PDCCH or mu_PUSCH may have values ​​of 0, 1, 2, or 3.

[0132] Referring to Figure 13, let's assume that the terminal receives a PDCCH that schedules a PUSCH in DL slot n. Let's also assume that the DCI transmitted in the PDCCH indicates K2=3. Let's also assume that the SCS of the DL BWP where the PDCCH is received and the SCS of the UL BWP where the PUSCH is transmitted are the same. In this case, the terminal can determine that a PUSCH is scheduled in UL slot n+K2=n+3.

[0133] The terminal can determine which symbol PUSCH is assigned to in a slot determined based on the K2 value, using the index (S) and length (L) of the starting symbol. The symbol PUSCH is assigned to is symbol S to symbol S+L-1 in the slot determined based on the K2 value. Here, symbol S to symbol S+L-1 are L consecutive symbols.

[0134] The terminal may have an additional UL slot set configured by the base station. The UL slot set value may be 2, 4, or 8. Once the UL slot set is configured, the terminal can transmit PUSCH in consecutive slots corresponding to the slot set value, starting with the slot determined based on the K2 value.

[0135] In Figures 11 to 13, the terminal uses K0, K1, and K2 values ​​to determine which slot receives PDSCH, which slot sends PUCCH, and which slot sends PUSCH. For convenience, the slots obtained by assuming K0, K1, and K2 values ​​are 0 are called the reference point or reference slot.

[0136] In Figure 11, the reference slot to which the K0 value is applied is DL slot n, which received the PDCCH.

[0137] In Figure 12, the reference slot to which the K1 value is applied is the UL slot that overlaps with the last symbol of the PDSCH, i.e., UL slot n+3.

[0138] In Figure 13, the reference slot to which the K1 value is applied is the UL slot that overlaps with the last symbol of the PDCCH, i.e., UL slot n. The reference slot to which the K2 value is applied is also UL slot n.

[0139] For convenience, the following explanation assumes that the SCS of the DL BWP receiving PDSCH / PDCCH and the SCS of the UL BWP transmitting PUSCH / PUCCH are the same. Also, UL slots and DL slots are not distinguished separately but are simply referred to as slots.

[0140] In the above description, the terminal receives one DCI and, based on that DCI, receives a PDSCH or sends a PUSCH in one slot. However, if one DCI provides scheduling information for only one slot, then in order to schedule multiple slots, the same number of DCIs as the number of slots must be sent. This can result in wasted DL resources.

[0141] To solve this, a method may be used in which the terminal receives one DCI from the base station and receives PDSCHs in multiple slots based on the DCI. Here, the PDSCH received in each slot may contain individual DL data (e.g., DL-SCH data). More specifically, the PDSCH received in each slot may contain individual TB (transport block). In addition, the PDSCH received in each slot may have an individual HARQ process number. Furthermore, the PDSCH received in each slot may occupy an individual symbol in each slot.

[0142] Alternatively, a method may be used in which the terminal receives one DCI from the base station and transmits PUSCHs in multiple slots based on the DCI. Here, each PUSCH transmitted in a slot may contain individual UL data (e.g., UL-SCH data). More specifically, each PUSCH transmitted in a slot may contain individual TB. Also, each PUSCH transmitted in a slot may have an individual HARQ process number. Also, each PUSCH transmitted in a slot may occupy an individual symbol in that slot.

[0143] As described above, receiving PDSCH signals or transmitting PUSCH signals on multiple slots based on a single DCI is conveniently referred to as multi-slot scheduling.

[0144] For reference, multi-slot scheduling differs from existing slot sets (a method of repeatedly receiving PDSCH or repeatedly transmitting PUSCH using multiple slots) in the following ways.

[0145] - Existing slot sets are designed to repeatedly receive or transmit PDSCH or PUSCH signals with the same TB across multiple slots in order to expand coverage and improve reliability. However, multi-slot scheduling is designed to receive or transmit PDSCH or PUSCH signals with individual TBs across multiple slots in order to reduce the overhead of PDCCHs.

[0146] - In an existing DL slot set, a PDSCH containing the same TB is received in multiple slots, so the terminal determines whether it was successful to receive the same TB from the PDSCH received in multiple slots. Therefore, the terminal sends a HARQ-ACK to the base station for the single identical TB. However, in multi-slot scheduling, a PDSCH received in multiple slots contains a separate TB, so the terminal must determine whether it was successful to receive each TB. In addition, the terminal must send a HARQ-ACK to the base station for each TB.

[0147] Multi-slot scheduling will be explained using Figures 14 to 16.

[0148] Referring to Figure 14, one DCI can schedule PDSCH reception in multiple slots. In Figure 14, a PDCCH containing one DCI may be received in slot n. The TDRA field of the DCI can indicate the timing information K0 value of the scheduled slots, and the SLIV value which is the index and length of the starting symbol within each slot. More specifically, the first slot on which the PDSCH is transmitted may be determined based on the K0 value. PDSCH reception may be scheduled in M ​​consecutive slots starting from the first slot determined by the K0 value. In Figure 14, K0=3 and M=3. Therefore, PDSCH reception may be scheduled in slots n+3, n+4, and n+5. The terminal may be indicated by the index (S) of the starting symbol and the number of consecutive symbols (L) for PDSCH reception in each slot. (S,L) may be the same or different for each slot. If (S,L) differs for each slot, the index of the starting symbol for PDSCH reception (S) and the number of consecutive symbols (L) may be specified for each slot.

[0149] Table 4 shows an example TDRA table used for multi-slot scheduling. The TDRA table may consist of 12 entries, each entry may be assigned an index from 0 to 11. Here, at least one entry may be configured to schedule a PDSCH in multiple slots. For example, each entry can schedule a PDSCH in up to 4 slots. To this end, each entry may be given up to 4 SLIV and K0 values. Here, the K0 value indicates the difference between the slot where the PDCCH was received and the slot where the PDSCH is received (PDCCH-to-PDSCH slot offset). SLIV indicates the starting index (S) and the number of consecutive symbols (L) of the symbol in which the PDSCH is received in one slot. In Table 4, a PDSCH scheduled in one slot may be represented as (K0, S, L).

[0150] If multi-slot scheduling allows PDSCH to be scheduled in consecutive slots, the K0 value indicating the scheduled slot may be omitted in the TDRA table. For example, referring to Table 5, each entry in the TDRA table may contain only one K0 value. Furthermore, each entry (or at least one entry) in the TDRA table may contain two or more SLIV values ​​(i.e., (S,L)). In this case, PDSCH reception may be scheduled for the symbol corresponding to the first SLIV value (first (S,L)) in the slot determined by the K0 value, and PDSCH reception may be scheduled for the symbol corresponding to the second SLIV value (second (S,L)) in the next slot. Specifically, in the TDRA table, the K0 of each entry is {K0 r ,K0 r +i,...,K0 r +M r It can be determined that K0 r This indicates K0 of the r-th entry, and M r This corresponds to the number of SLIV values ​​included in the r-th entry.

[0151] If multi-slot scheduling allows PDSCH to be scheduled in discontinuous slots, the TDRA table may include (i) a K0 value and (ii) an offset (O) value. Here, the offset value represents the difference (slot index) between the slot indicated by the K0 value and the slot instructed to receive the PDSCH. For example, referring to Table 6, each entry in the TDRA table may include only one K0 value. Each SLIV may further have an offset value (O in Table 6). For reference, the offset value may be omitted in the SLIV for the slot indicated by the K0 value. Therefore, in the TDRA table, the K0 of each entry is {K0 r ,K0 r +O 1,r ,...,K0 r +O M-1,r} can be determined. Here, K0 r This represents K0 of the r-th entry, O i,rrepresents the (slot) offset value for the i-th scheduling of the r-th entry. M corresponds to the number of SLIV values ​​contained in each entry.

[0152] As another example, if multi-slot scheduling allows PDSCH to be scheduled in discontinuous slots, the TDRA table may have the structure shown in Table 7.

[0153] [Table 4]

[0154] [Table 5]

[0155] [Table 6]

[0156] [Table 7]

[0157] For the sake of explanation, this invention describes the case where PDSCH is scheduled in multiple consecutive slots. Therefore, unless otherwise specified, the K0 value is omitted. However, this invention also includes the case where PDSCH is scheduled in multiple discontinuous slots (see Table 7).

[0158] Referring to Figure 15, a HARQ-ACK for a PDSCH scheduled to be received in multiple slots by a single DCI may be transmitted as a PUCCH in one slot. Here, the UL slot that coincides with the end of the last PDSCH among the PDSCHs received in multiple slots can be determined to be the UL slot with a K1 value of 0. In Figure 15, UL slot n+5 is the UL slot with a K1 value of 0 and corresponds to the reference slot. The terminal may be instructed to send one K1 value from the single DCI. In this case, the HARQ-ACK for the multi-slot scheduled PDSCH can be transmitted in the UL slot corresponding to the single K1 value.

[0159] Referring to Figure 16, a HARQ-ACK for a PDSCH scheduled to be received in multiple slots by a single DCI may be transmitted as a PUCCH in two or more slots. The method for doing so is as follows: First, multi-slot scheduled PDSCHs can be grouped together. Here, when grouping PDSCHs, consecutive PDSCHs in chronological order (i.e., sequentially by time) can be grouped together. In Figure 16, a single DCI is scheduled to receive PDSCHs in three slots. Of the three PDSCHs in the aforementioned slots, the first two PDSCHs can be grouped together (group 0), and the last PDSCH can be grouped together in another group (group 1). The specific method for grouping them together is as follows:

[0160] As a first method, terminals can be grouped based on the number of PDSCHs scheduled by a single DCI. Here, if the number of PDSCHs is greater than a certain number, a group can be formed by combining only that number of PDSCHs. For example, if the certain number is 2 and the number of PDSCHs is 4, groups can be formed by combining two PDSCHs at a time. Here, the certain number may be set by the base station.

[0161] As a second method, terminals can be grouped based on a predetermined number of groups set by a single DCI. That is, the terminals may be assigned a predetermined number of groups from the base station. For example, if the predetermined number of groups is 2 and the number of PDSCHs scheduled by one DCI is 6, then the 6 PDSCHs can be divided into 2 groups. In this case, the PDSCHs may be grouped into one group sequentially according to time (order), and each group should have as many PDSCHs as possible that are equal, with a difference of up to one.

[0162] As a third method, grouping information may be set for each TDRA entry. Specifically, each TDRA entry contains information for PDSCH reception in multiple slots. This may include information on which slots' PDSCHs are grouped into one group. That is, along with the SLIV of each slot, an index of the group to which the SLIV belongs may be included. Referring to Table 8, each entry in the TDRA table may include an index (G) of the group to which the SLIV belongs. Here, an SLIV belonging to G=0 corresponds to group 0, and an SLIV belonging to G=1 corresponds to group 1.

[0163] [Table 8]

[0164] A terminal can send a HARQ-ACK for a PDSCH included in a group using a PUCCH in a UL slot. Here, the method for determining the UL slot includes identifying the UL slot that coincides with the end of the last PDSCH included in the group as the UL slot with a K1 value of 0 (i.e., the reference slot). That is, in Figure 16, the reference slot for group 0 is slot n+4, and the reference slot for group 1 is slot n+5.

[0165] A terminal may be instructed by one DCI to have one K1 value. In this case, for each group, the terminal can send a HARQ-ACK of a PDSCH that the DCI has scheduled to receive in multiple slots in the UL slot corresponding to the one K1. For example, in Figure 16, K1=2. The HARQ-ACKs of the two PDSCHs included in group 0 are sent in the PUCCH of slot n+4+2 (= reference slot index of group 0 + K1), and the HARQ-ACK of the one PDSCH included in group 1 is sent in the PUCCH of slot n+7 (= reference slot index of group 1 + K1).

[0166] The terminal may be instructed by the aforementioned DCI to have a K1 value for each group. In this case, for each group, the terminal can send a HARQ-ACK of a PDSCH that the aforementioned DCI has scheduled to receive in multiple slots, using the UL slot corresponding to the K1 of each group. For example, group 0 may be given a K1 value of 1, and group 1 may be given a K1 value of 2. In this case, the HARQ-ACKs of the two PDSCHs included in group 0 are sent via PUCCH in slot n+4+K1 (=reference slot index of group 0 + K1 of group 0), and the HARQ-ACK of the one PDSCH included in group 1 is sent via PUCCH in slot n+7 (=reference slot index of group 1 + K1 of group 1).

[0167] The present invention describes a method for transmitting HARQ-ACKs for PDSCHs when they are scheduled by multi-slot scheduling.

[0168] In an NR wireless communication system, a terminal can transmit a codebook containing HARQ-ACK information to signal whether it has successfully received a DL signal / channel (which requires HARQ-ACK feedback). A HARQ-ACK codebook contains one or more bits indicating whether it has successfully received a DL channel / signal. Here, the DL channel / signal (which requires HARQ-ACK feedback) may include at least one of the following: i) PDSCH, ii) SPS (semi-persistence scheduling) PDSCH, and iii) PDCCH indicating the release of an SPS PDSCH. HARQ-ACK codebook types can be distinguished into semi-static HARQ-ACK codebooks (or Type-1 HARQ-ACK codebooks) and dynamic HARQ-ACK codebooks (or Type-2 HARQ-ACK codebooks). A base station can configure a terminal to use one of these two HARQ-ACK codebook types. Based on the configured HARQ-ACK codebook type, the terminal can generate and transmit a HARQ-ACK codebook for the DL channel / signal.

[0169] Type-1 (or semi-static) HARQ-ACK codebook

[0170] When a semi-static HARQ-ACK codebook is used, the base station can pre-configure information (e.g., a K1 set) used with the RRC signal to determine the number of bits in the HARQ-ACK codebook and whether each bit in the HARQ-ACK codebook indicates whether or not the DL signal / channel was successfully received. Therefore, the base station does not need to signal the terminal with the information necessary for HARQ-ACK codebook transmission each time it is required.

[0171] Specifically, in existing single-slot scheduling, the method for generating a Type-1 HARQ-ACK codebook is as follows: In single-slot scheduling, DCI schedules a PDSCH in one slot. For convenience, we assume that a Type-1 HARQ-ACK codebook is sent in slot n. Here, slot n may be determined by the value of the PDSCH-to-HARQ_feedback indicator (i.e., K1) in DCI format 1_x(PDCCH).

[0172] 1) Stage 1: Let K1_set be the set of K1 values ​​that can be specified by DCI. In DCI format 1_0, K1_set is {0,1,2,3,4,5,6,7}. In DCI formats 1_1 and 1_2, K1_set may be configured / set by a higher layer (e.g., RRC). The terminal first extracts the largest K1 value in K1_set (hereinafter referred to as K1_max). Then, K1_max is removed from K1_set.

[0173] 2) Two-stage: Let R be the set of PDSCH candidates that can be received in slot n-K1_max. Each PDSCH candidate in set R has a starting symbol and length in the slot according to the TDRA table. If the symbol of a PDSCH candidate in set R overlaps with at least one symbol of a symbol configured as UL in a semi-static UL / DL configuration, the PDSCH candidate is excluded from set R.

[0174] 3) Three steps: The terminal performs steps A and B for the PDSCH candidates included in R.

[0175] - Step A: Assign a new HARQ-ACK opportunity to the PDSCH candidate in set R whose last symbol is the earliest. Then, if there is a PDSCH candidate in set R whose last symbol overlaps with the earliest PDSCH candidate by at least one symbol, assign the same HARQ-ACK opportunity to that PDSCH candidate. PDSCH candidates to which a HARQ-ACK opportunity has been assigned (i.e., (i) the PDSCH candidate whose last symbol is the earliest and (ii) any PDSCH candidate that overlaps with that PDSCH candidate by at least one symbol) are removed from set R.

[0176] - Step B: Repeat Step A until the set R becomes an empty set.

[0177] 4) Repeat steps 1), 2), and 3) until K1_set becomes an empty set.

[0178] Subsequently, the terminal can generate a Type-1 HARQ-ACK codebook based on the assigned HARQ-ACK opportunity. For example, if a PDSCH corresponding to a HARQ-ACK opportunity is received, the HARQ-ACK opportunity may be set to the HARQ-ACK information of the PDSCH. However, if no PDSCHs corresponding to a HARQ-ACK opportunity are received, the HARQ-ACK opportunity may be set to NACK. A single HARQ-ACK opportunity may contain one or more HARQ-ACK bits. For example, if a PDSCH contains one TB (or if spatial bundling is set for the TB in the PDSCH), the HARQ-ACK opportunity may contain one HARQ-ACK bit. Also, if a PDSCH contains two TBs (and spatial bundling is not set), the HARQ-ACK opportunity may contain two HARQ-ACK bits. Furthermore, when CBG (code block group) based PDSCH reception is configured, a HARQ-ACK opportunity may contain HARQ-ACK bits corresponding to the maximum number of CBGs that a single PDSCH may contain.

[0179] Figure 17 illustrates the PDSCH candidate positions and HARQ-ACK opportunities in an existing single-slot scheduling scenario where K1_set={0,1,2,3,4}. Referring to Figure 17, the terminal is in slot n-K1 i This allows us to determine the PDSCH candidates that can be received. K1 i This corresponds to the i-th value after sorting K1_set in descending order. Thus, the terminal can determine the set R of PDSCH candidates in each slot {slot n-4, ..., slot n} and assign a HARQ-ACK opportunity to the PDSCH candidates in set R. For convenience, we assume that one HARQ-ACK opportunity is assigned to each PDSCH candidate in each slot, and that there is one bit per HARQ-ACK opportunity. Thus, a Type-1 HARQ-ACK codebook consists of five HARQ-ACK bits (o0~o4).

[0180] Subsequently, for the sake of explanation, this invention assumes 1 bit per HARQ-ACK opportunity.

[0181] On the other hand, when PDSCH is scheduled by multi-slot scheduling, applying existing methods as they are will not correctly construct the Type-1 HARQ-ACK codebook. For illustrative purposes, let's assume that the terminal has K1_set={1,2} set by the RRC. This allows the terminal to be instructed to use K1=1 or K1=2 by the PDSCH-to-HARQ_feedback indicator in DCI. Given the TDRA table in Table 4, the PDSCH candidates corresponding to the HARQ-ACK to be transmitted via PUCCH in slot n are shown in Figure 18. However, existing Type-1 HARQ-ACK codebook generation methods determine the set R of PDSCH candidates that can be received in slot n-K1_max based only on the K1 value of K1_set. Therefore, only the PDSCH candidates for slots n-2 and n-1 can be used to generate the Type-1 HARQ-ACK codebook (see the dotted box in Figure 18).

[0182] The following proposes a method for generating a Type-1 HARQ-ACK codebook when PDSCH is scheduled by multi-slot scheduling. Refer to Table 4 and Figure 18 in the following explanation. Multi-slot scheduling operation may be configured on a per-cell (or per-component carrier) basis. Cells in the overall configuration of the terminal that are not configured with multi-slot scheduling may operate using the existing single-slot scheduling method.

[0183] Proposal 1: PDSCH candidate base in slot

[0184] Proposal 1 is a method for converting a multi-slot scheduled PDSCH into a PDSCH candidate for each slot, and then generating a Type-1 HARQ-ACK codebook using the PDSCH candidate in each slot. For example, the Type-1 HARQ-ACK codebook generation method according to Proposal 1 is as follows:

[0185] 1) Stage 1: Let K1_set be the set of K1 values ​​that can be instructed to the terminal. In Proposal 1, the terminal can determine the index of the slot where the PDSCH candidate corresponding to the Type-1 HARQ-ACK codebook is located / received, based on K1_set and the TDRA table. Let K_slot be the set of such slot indices.

[0186] Specifically, the method for determining K_slot is as follows: The terminal can select one K1 value from K1_set. Let's call the selected K1 value K1_a. In this case, based on K1_a and the TDRA table, the terminal can determine which slot it must receive the PDSCH. For example, if the TDRA table contains PDSCH assignment information for up to N consecutive slots, the terminal can determine {slot n-K1_a-(N-1), slot n-K1_a-(N-2), ..., slot n-K1_a} as PDSCH assignment information based on K1_a and the TDRA table. Therefore, the K_slot set may include {K1_a+(N-1), K1_a+(N-2), ..., K1_a}. For reference, the TDRA table may also include PDSCH assignment information for discontinuous slots. Here, slot n is the slot to which the Type-1 HARQ-ACK codebook is sent, and N is the number of scheduled slots in the TDRA table from the first scheduled slot to the last scheduled slot. Slots not scheduled by the TDRA table from {slot n - K1_a - (N-1) ~ slot n - K1_a} may be excluded. Finally, K_slot(K1_a) is defined as {K1_a + (N-1), K1_a + (N-2), ..., K1_a}. (Ni) corresponds to the slot index difference between the last slot that can be PDSCH assigned and the i-th slot that can be PDSCH assigned, based on the TDRA table. Here, the slot index difference corresponds to the difference between KO values: for example, (Ni) = (K0 max -KO i ). Here, K0 max This represents the maximum value among K0, KO irepresents the i-th KO value (see Table 4). K_slot(K1_a) corresponds to the union of K_slots determined for each entry: K_slot(K1_a,r)={K1_a+(Nr-1),K1_a+(Nr-2),...,K1_a}. Here, r represents the entry index in the TDRA table, and Nr corresponds to the number of PDSCH / slot assignment information (e.g., KO, SLIV) contained in the r-th entry in the TDRA table. Here, (Nr-i) is (K0 max,r -KO i,r ) may be replaced with. Here, K0 max,r This represents the maximum value among multiple KO values ​​corresponding to the r-th entry in the TDRA table, and KO i This represents the i-th KO value among multiple KO values ​​corresponding to the r-th entry in the TDRA table (see Table 4).

[0187] The same operation can be performed on the remaining K1 values ​​in K1_set to find the indices of slots capable of receiving PDSCH candidates for all K1 values ​​in K1_set, and these indices can be collected and included together in the K_slot set.

[0188] 2) Two-stage: The maximum K1 value (hereinafter referred to as K1_max) is extracted from K_slot. Then, K1_max is removed from K_slot. This corresponds to the existing one-stage process, and K_slot is used instead of K1_set.

[0189] 3) Three stages: Let R be the set of PDSCH candidates that can be received in slot n-K1_max. If the symbol of a PDSCH candidate included in set R overlaps with at least one symbol of a symbol configured as UL in a semi-static UL / DL configuration, the PDSCH candidate is excluded from set R.

[0190] In slot n-K1_max, the PDSCH candidates included in set R can be determined as follows: The terminal can select one K1 value from K1_set. Let's call the selected K1 value K1_a. Based on the K1_a value and the TDRA table, the terminal can determine the PDSCH candidates in a multi-slot configuration. For example, if one entry in the TDRA table contains PDSCH assignment information for M consecutive slots, the terminal can determine {slot n-K1_a-(M-1), slot n-K1_a-(M-2), ..., slot n-K1_a} as PDSCH assignment information based on K1_a and the TDRA table. If one of the slots {n-K1_a-(M-1), slot n-K1_a-(M-2), ..., slot n-K1_a} is slot n-K1_max, then the PDSCH candidates included in slot n-K1_max may be included in set R. The above process may be performed for all entries in the TDRA table and for all K1 values ​​in K1_set.

[0191] 4) 4 steps: The terminal performs steps A and B for the PDSCH candidates in set R.

[0192] - Step A: Assign a new HARQ-ACK opportunity to the PDSCH candidate in set R whose last symbol is the earliest. Then, if there is a PDSCH candidate in set R whose last symbol overlaps with the earliest PDSCH candidate by at least one symbol, assign the same HARQ-ACK opportunity to that PDSCH candidate. PDSCH candidates to which a HARQ-ACK opportunity has been assigned (i.e., (i) the PDSCH candidate whose last symbol is the earliest and (ii) PDSCH candidates that overlap with that PDSCH candidate by at least one symbol) are removed from set R.

[0193] - Step B: Repeat Step A until the set R becomes an empty set.

[0194] 5) 5 steps: Repeat steps 2 / 3 / 4 until K_slot becomes an empty set.

[0195] Proposal 1 will be explained with reference to Figure 19.

[0196] 1) Stage 1: Since 1 and 2 have been set as K1 values ​​(by RRC), K1_set={1,2}. The terminal can determine K_slot through the following process.

[0197] The terminal selects one of the values ​​in K1_set. Let's call this K1_a=2. In the TDRA table, an entry contains PDSCH assignment information for a maximum of N=4 consecutive slots. Based on K1_a=2 and the TDRA table, the terminal can determine that {slot n-K1_a-(N-1)=n-2-(4-1)=n-5, slot n-K1_a-(N-2)=n-2-(4-2)=n-4, slot n-K1_a-(N-3)=n-2-(4-3)=n-3, slot n-K1_a=n-2} are PDSCH assignment information. Therefore, K_slot(K1_a=2) contains {5,4,3,2}. K_slot(K1_a=2) is the union of K_slot(K1_a=2,r).

[0198] - K_slot(K1_a=2, r=0~2):{K1_a+(Nr-1)=2+(2-1)=3,K1_a+(Nr-2)=2+(2-2)=2} or {K1_a+(K0max,r-K01,r)=2+(1-0)=3,K1_a+(K0max,r-K02,r)=2+(1-1)=2}

[0199] - K_slot(K1_a=2, r=3~5):{5,4,3,2}

[0200] - K_slot(K1_a=2, r=6~11):{3,2}

[0201] The terminal selects the remaining value from K1_set. Let's call this K1_a=1. In the TDRA table, an entry contains PDSCH assignment information for a maximum of N=4 consecutive slots. Based on K1_a=1 and the TDRA table, the terminal can determine that {slot n-K1_a-(N-1)=n-1-(4-1)=n-4, slot n-K1_a-(N-2)=n-1-(4-2)=n-3, slot n-K1_a-(N-3)=n-1-(4-3)=n-2, slot n-K1_a=n-1} is PDSCH assignment information. Therefore, K_slot(K1_a=1) contains {4,3,2,1}. K_slot(K1_a=1) corresponds to the union of K_slot(K1_a=1,r).

[0202] - K_slot(K1_a=1, r=0~2):{K1_a+(Nr-1)=1+(2-1)=2,K1_a+(Nr-2)=1+(2-2)=1} or {K1_a+(K0max,r-K01,r)=1+(1-0)=2,K1_a+(K0max,r-K02,r)=1+(1-1)=1}

[0203] - K_slot(K1_a=1, r=3~5):{4,3,2,1}

[0204] - K_slot(K1_a=1, r=6~11):{2,1}

[0205] Therefore, ultimately, K_slot contains {5,4,3,2,1} (i.e., the union of K_slot(K1_a=2) and K_slot(K1_a=1)).

[0206] 2) Two-step process: Select the maximum value K1_max=5 from K_slot. Then, K1_max=5 is removed from K_slot.

[0207] 3) Three - stage: Let the set of PDSCH candidates that can be received at slot n - K1_max = n - 5 be R. If the symbols of the PDSCH candidates included in set R overlap with the symbols configured as UL in the semi - static UL / DL configuration, the said PDSCH candidates are excluded from set R. For the sake of convenience in explanation, in this example, all symbols within a slot are assumed to be DL symbols.

[0208] The PDSCH candidates included in set R at slot n - 5 can be obtained as follows.

[0209] The terminal selects one of the values in K1_set. Let this be K1_a = 2. Entries 3, 4, 5 in the TDRA table contain the PDSCH allocation information for 4 (M) consecutive slots, namely {slot n - K1_a-(M - 1)=n - 5, slot n - K1_a-(M - 2)=n - 4, slot n - K1_a-(M - 3)=n - 3, slot n - K1_a-(M - 4)=n - 2}, and the remaining entries (0, 1, 2, 6, 7, 8, 9, 10, 11) contain the PDSCH allocation information for 2 consecutive slots, namely {slot n - 3, slot n - 2}. Therefore, since entries 3, 4, 5 in the TDRA table contain PDSCH candidates for slot n - K1_max = n - 5, the PDSCH candidates included in slot n - 5 can be included in set R. That is, the set R of PDSCH candidates that can be received at slot n - K1_max = n - 5 includes the following: {(S = 0, L = 14), (S = 0, L = 7), (S = 7, L = 7)}. For reference, (S = 0, L = 14) is the PDSCH candidate for slot n - 5 in entry 3 of the TDRA table, (S = 0, L = 7) is the PDSCH candidate for slot n - 5 in entry 4 of the TDRA table, and (S = 7, L = 7) is the PDSCH candidate for slot n - 5 in entry 5 of the TDRA table.

[0210] Select the remaining one value from K1_set. Let's set this as K1_a = 1. Entries 3, 4, and 5 in the TDRA table contain PDSCH allocation information for 4 (M) consecutive slots, i.e., {slot n - K1_a - (M - 1) = n - 4, slot n - K1_a - (M - 2) = n - 3, slot n - K1_a - (M - 3) = n - 2, slot n - K1_a - (M - 4) = n - 1}, and the remaining entries (0, 1, 2, 6, 7, 8, 9, 10, 11) contain PDSCH allocation information for 2 consecutive slots, i.e., {slot n - 2, slot n - 1}. Therefore, since the slot corresponding to K1_a = 1 does not overlap with slot n - K1_max = n - 5, there is no PDSCH candidate to include in set R.

[0211] Therefore, R = {(S = 0, L = 14), (S = 0, L = 7), (S = 7, L = 7)}.

[0212] 4) Fourth step: The terminal performs step A and step B for the PDSCH candidates in set R.

[0213] - Step A: Among the PDSCH candidates in set R, assign HARQ-ACK opportunity 0 to the PDSCH candidate (S = 0, L = 7) with the earliest last symbol. And assign the same HARQ-ACK opportunity to the PDSCH candidate (S = 0, L = 14) that overlaps with the PDSCH candidate (S = 0, L = 7) by even one symbol in set R. The PDSCH candidates (S = 0, L = 7) and (S = 0, L = 14) to which the HARQ-ACK opportunity is assigned are excluded from set R. Therefore, set R = {(S = 7, L = 7)}.

[0214] - Step B: Repeat step A until set R becomes an empty set. In this example, since set R is not an empty set, repeat step A. By step A, HARQ-ACK opportunity 1 is assigned to the PDSCH candidate (S = 7, L = 7), and set R becomes an empty set. Thus, the fourth step ends.

[0215] 5) Step 5: Repeat steps 2 / 3 / 4 until K_slot becomes an empty set. In this example, K_slot = {4, 3, 2, 1}, and therefore it is not an empty set. Since K_slot is not an empty set, repeat steps 2 / 3 / 4.

[0216] These stages determine the PDSCH candidates and HARQ-ACK opportunities as follows:

[0217] HARQ-ACK opportunity 0: PDSCH candidates for slot n-5 (S=0, L=7), (S=0, L=14)

[0218] HARQ-ACK opportunity 1: PDSCH candidate for slot n-5 (S=7, L=7)

[0219] HARQ-ACK opportunity 2: PDSCH candidates for slot n-4 (S=0, L=7), (S=0, L=14)

[0220] HARQ-ACK opportunity 3: PDSCH candidate for slot n-4 (S=7, L=7)

[0221] HARQ-ACK opportunity 4: PDSCH candidates for slot n-3 (S=0, L=7), (S=0, L=14)

[0222] HARQ-ACK opportunity 5: PDSCH candidate for slot n-3 (S=7, L=7)

[0223] HARQ-ACK opportunity 6: PDSCH candidates for slot n-2 (S=0, L=7), (S=0, L=14)

[0224] HARQ-ACK opportunity 7: PDSCH candidate for slot n-2 (S=7, L=7)

[0225] HARQ-ACK opportunity 8: PDSCH candidates for slot n-1 (S=0, L=7), (S=0, L=14)

[0226] HARQ-ACK opportunity 9: PDSCH candidate for slot n-1 (S=7, L=7)

[0227] Therefore, a Type-1 HARQ-ACK codebook may consist of 10 HARQ-ACK opportunities.

[0228] For example, suppose the DCI received by the terminal indicates (i) entry 4 in the TDRA table and (ii) K1=2. In this case, the terminal receives the first PDSCH (S=0,L=7) in slot n-5, the second PDSCH (S=0,L=7) in slot n-4, the third PDSCH (S=0,L=7) in slot n-3, and the fourth PDSCH (S=0,L=7) in slot n-2. The terminal includes the HARQ-ACK (o1) of the first PDSCH in HARQ-ACK opportunity 0, the HARQ-ACK (o2) of the second PDSCH in HARQ-ACK opportunity 2, the HARQ-ACK (o3) of the third PDSCH in HARQ-ACK opportunity 4, and the HARQ-ACK (o4) of the fourth PDSCH in HARQ-ACK opportunity 6. Therefore, a Type-1 HARQ-ACK codebook may be structured as [o1 N o2 N o3 N o4 NNN], where N represents NACK.

[0229] Let's also assume that the DCI received by the terminal indicates (i) entry 5 in the TDRA table and (ii) K1=1. In this case, the terminal receives the 5th PDSCH (S=7,L=7) in slot n-4, the 6th PDSCH (S=7,L=7) in slot n-3, the 7th PDSCH (S=7,L=7) in slot n-2, and the 8th PDSCH (S=7,L=7) in slot n-1. The terminal includes the HARQ-ACK (o5) of the 5th PDSCH in HARQ-ACK opportunity 3, the HARQ-ACK (o6) of the 6th PDSCH in HARQ-ACK opportunity 5, the HARQ-ACK (o7) of the 7th PDSCH in HARQ-ACK opportunity 7, and the HARQ-ACK (o8) of the 8th PDSCH in HARQ-ACK opportunity 9. Therefore, a Type-1 HARQ-ACK codebook may be structured as [o1 N o2 o5 o3 o6 o4 o7 N o8], where N represents NACK.

[0230] Proposal 1 creates HARQ-ACK opportunities using the PDSCH candidates in each slot. However, one DCI can schedule PDSCH in multiple slots, so creating HARQ-ACK opportunities using the PDSCH candidates in each slot can be inefficient. For example, in FIG. 19, the terminal may schedule up to 8 PDSCHs in any case. This is the case as follows.

[0231] (Entry 4 of the TDRA table and K1 = 2, Entry 5 of the TDRA table and K1 = 2)

[0232] (Entry 4 of the TDRA table and K1 = 2, Entry 5 of the TDRA table and K1 = 1)

[0233] (Entry 4 of the TDRA table and K1 = 1, Entry 5 of the TDRA table and K1 = 2)

[0234] (Entry 4 of the TDRA table and K1 = 1, Entry 5 of the TDRA table and K1 = 1)

[0235] Therefore, the Type-1 HARQ-ACK codebook transmitted by the terminal may include 8 HARQ-ACK opportunities. However, according to Proposal 1, 10 HARQ-ACK opportunities are included. Therefore, 2 HARQ-ACK opportunities are not always used when transmitting HARQ-ACK information.

[0236] FIG. 20 illustrates a method for configuring the HARQ-ACK codebook according to Proposal 1.

[0237] Referring to FIG. 20, the terminal can receive a PDCCH having the following information (S2002): (i) index information indicating an entry in the TDRA table for PDSCH allocation, and (ii) a set K1 of PDSCH-to-HARQ slot timings {K1 iTiming information that indicates a single value within}(i=1,2,...). When slot n is indicated by the aforementioned timing information, the terminal indicates slot n-K1 for all K1 values ​​in the K1 set. i The PDSCH candidates can be determined (S2004). The terminal can then transmit a semistatic HARQ-ACK codebook in slot n based on the PDSCH candidates for each slot determined.

[0238] Here, if multi-slot scheduling is configured (for example, if at least one entry in the TDRA table is associated with multiple PDCCH-to-PDSCH slot timing K0 values), the K1 set may be replaced with the union of the following K sets #i when determining the PDSCH candidate:

[0239] - K set #i:{K1 i +d1,K1 i +d2,...,K1 i +d N},

[0240] Here, dk(k=1,2,...,N) corresponds to the slot index difference between the last slot that can be PDSCH-to-PDSCH assigned and the kth slot that can be PDSCH assigned, based on the multiple PDCCH-to-PDSCH timing K0 values ​​across all entries in the TDRA table.

[0241] Here, the SCS applied to the PDCCH and the SCS applied to the semistatic HARQ-ACK codebook may be the same. Furthermore, for each determined slot PDSCH candidate, multiple HARQ-ACK opportunities may be sequentially assigned to non-overlapping PDSCH candidates based on the earliest PDSCH candidate, with the last symbol being the reference point, and the semistatic HARQ-ACK codebook may be constructed based on these multiple HARQ-ACK opportunities. In addition, when the time-domain bundling described later is applied to the semistatic HARQ-ACK codebook, the multiple HARQ-ACK opportunities may be assigned based on the PDSCH candidate of the last slot to which PDSCH assignment is possible for each bundling group based on each entry in the TDRA table. Furthermore, the radio communication system may include a 3GPP NR-based radio communication system.

[0242] Proposal 2: PDSCH candidate base for all slots

[0243] Proposal 2 is a method for generating a Type-1 HARQ-ACK codebook using PDSCH candidates in all slots. For example, the method for generating a Type-1 HARQ-ACK codebook according to Proposal 2 is as follows:

[0244] 1) Stage 1: A terminal may include a set of schedulable PDSCH candidate pairs in set R. Here, a PDSCH candidate pair is a collection of schedulable PDSCH candidates represented by a single entry in the TDRA table. Thus, a PDSCH candidate pair represents a PDSCH candidate that can be scheduled for reception in multiple slots. If at least one symbol of a PDSCH candidate included in a PDSCH candidate pair included in set R overlaps with a symbol configured with UL in a semi-static UL / DL configuration, the PDSCH candidate is excluded from the PDSCH candidate pair. Once all PDSCH candidates have been excluded from a PDSCH candidate pair, the PDSCH candidate pair is excluded from set R.

[0245] 2) Two steps: The terminal performs steps A and B for the PDSCH candidate pairs in set R.

[0246] - Step A: Select one PDSCH candidate pair from the PDSCH candidate pairs in set R. Assign a new HARQ-ACK opportunity to the selected PDSCH candidate pair. If there is another PDSCH candidate pair in set R that overlaps with the selected PDSCH candidate pair by even one symbol, assign the same HARQ-ACK opportunity to that PDSCH candidate pair. The PDSCH candidate pair to which the HARQ-ACK opportunity has been assigned is removed from set R.

[0247] - Step B: Repeat Step A until the set R becomes an empty set.

[0248] Unlike Proposal 1, in Proposal 2, a HARQ-ACK opportunity corresponds to a PDSCH candidate pair. Each PDSCH candidate pair may contain a different number of PDSCH candidates. Therefore, the number of PDSCH candidates that a single HARQ-ACK opportunity should represent may vary. To address this, the number of PDSCH candidates that a HARQ-ACK opportunity should represent may be determined based on the largest number of PDSCH candidates in the PDSCH candidate pairs corresponding to a single HARQ-ACK opportunity.

[0249] In step A, the terminal must select one PDSCH candidate pair from the set R. To do this, at least the following methods or a combination of the following methods may be considered.

[0250] As a first method, a PDSCH candidate pair can be selected that includes the earliest-starting PDSCH candidate. This allows for preferential allocation of HARQ-ACK opportunities to the PDSCH candidate that occurred earliest in time.

[0251] A second method allows selecting the PDSCH candidate pair that finishes earliest. This allows for preferential allocation of HARQ-ACK opportunities to the PDSCH candidate that finishes earliest in terms of time.

[0252] A third method involves selecting the PDSCH candidate pair with the fewest symbols. This ensures that the selected PDSCH candidate pair overlaps minimally with other PDSCH candidate pairs.

[0253] A fourth method involves selecting the PDSCH candidate pair with the most symbols. This allows the selected PDSCH candidate pair to overlap with the PDSCH candidate pair with the most symbols, thus excluding a large number of PDSCH candidates from the set R.

[0254] A fifth method involves selecting the PDSCH candidate pair with the most slots. As mentioned earlier, the number of PDSCH candidates that a HARQ-ACK opportunity should indicate is determined by the number of PDSCH candidates in the PDSCH candidate pair. Therefore, we can search for overlapping PDSCH candidate pairs with fewer slots, focusing on the PDSCH candidate pair with the most slots.

[0255] A sixth method is to select the PDSCH candidate pair with the lowest index in the TDRA table. This may be set when the base station configures the TDRA table.

[0256] Time domain bundling

[0257] When a terminal generates a Type-1 HARQ-ACK codebook, time-domain bundling may be configured by the base station. Time-domain bundling is a method of bundling the HARQ-ACKs of each PDSCH into a single HARQ-ACK bit (e.g., a binary 'AND' operation), generating the HARQ-ACK as a single HARQ-ACK bit (i.e., if all the HARQ-ACKs are ACKs, one HARQ-ACK bit is an ACK; otherwise, one HARQ-ACK bit is a NACK), and transmitting it. Here, the PDSCHs to which time-domain bundling is applied may be PDSCHs in the same slot or PDSCHs in different slots. Here, the PDSCHs to which time-domain bundling is applied are PDSCHs scheduled in one DCI and adjacent PDSCHs when the PDSCHs are aligned in time. For example, if a single DCI is scheduled to have PDSCH#0 in slot n, PDSCH#1 in slot n+1, PDSCH#2 in slot n+2, and PDSCH#3 in slot n+3, the terminal may bundle the HARQ-ACK of {PDSCH#0 in slot n, PDSCH#1 in slot n+1} with one HARQ-ACK bit, and bundle the HARQ-ACK of {PDSCH#2 in slot n+2, PDSCH#3 in slot n+3} with the other HARQ-ACK bits. Thus, although four HARQ-ACK bits are generated for the four PDSCHs, only two HARQ-ACK bits may be transmitted due to time-domain bundling.

[0258] The terminal may be configured with at least one of the following pieces of information from the base station for time-domain bundling:

[0259] As first information, the base station can set the number of HARQ-ACKs (or PDSCHs) to bundle for time-domain bundling. bundle Let's assume that. N bundleThis can be any one of the following values: 1, 2, 4, or 8. Enter N in the terminal. bundle When this setting is enabled, the device will be N bundle The HARQ-ACKs of each PDSCH are bundled into a single HARQ-ACK bit and transmitted. Let's assume that M PDSCHs are scheduled in one DCI. M is N bundle If it is a multiple of (M mod N) bundle =0), the terminal is N bundle Each PDSCH is combined to generate one bundled HARQ-ACK, and the total M / N bundle It is possible to generate bundled HARQ-ACKs. However, if M is N bundle If it is not a multiple of (M mod N) bundle >0), the terminal can group the PDSCH as follows. For reference, here PDSCH#0, PDSCH#1, ..., PDSCH#(M-1) are arranged in chronological order.

[0260] As the first method, N in chronological order bundle The individual PDSCHs are combined to generate a single bundled HARQ-ACK. Assuming the number of remaining PDSCHs is N... bundle If the number is less than the specified number, the remaining PDSCHs are grouped together to generate a single bundled HARQ-ACK. More specifically, {PDSCH#0,PDSCH#1,…,PDSCH#(N bundle Combine the {PDSCH#(N bundle ),PDSCH#(N bundle +1), ..., PDSCH#(2*N bundle -1)} are combined to generate a single bundled HARQ-ACK. Continue combining in this manner, {PDSCH#(floor(M / N bundle )*N bundle ),PDSCH#(floor(M / N bundle )*N bundle Combine the +1), ..., PDSCH#(M-1)} to generate a single bundled HARQ-ACK. As a result, the total ceil(M / N bundle The bundled HARQ-ACK bits are generated.

[0261] As a second method, the PDSCHs can be grouped into K = ceil(M / N bundle ) groups in chronological order. The number of PDSCHs included in each group may be ceil(M / K) or floor(M / K). M mod K groups can be created by grouping ceil(M / K) PDSCHs in chronological order, and then K-(M mod K) groups can be created by grouping floor(M / K) PDSCHs in chronological order. The HARQ-ACKs within the group can be bundled to generate one bundled HARQ-ACK, and as a result, a total of ceil(M / N bundle ) bundled HARQ-ACK bits are generated.

[0262] As a second piece of information, the base station can set the number of bundled HARQ-ACKs (or the number of PDSCH / banding groups) for time-domain bundling. Let this be N group . Let N group be any one of the values 1, 2, 4, 8. When N group is set for the terminal, the terminal can group M PDSCHs into N group PDSCH groups. For reference, if M is smaller than N group , M PDSCH groups can be created by grouping one PDSCH, and the next N group - M groups do not contain PDSCHs. The HARQ-ACK of a group that does not contain PDSCH may be set to NACK. The HARQ-ACK of a group that does not contain PDSCH does not have to be transmitted to the base station.

[0263] As a first method, K = ceil(M / N group) PDSCHs can be combined to generate one bundled HARQ-ACK. If the number of remaining PDSCHs is less than K, the remaining PDSCHs can be combined to generate one bundled HARQ-ACK. For example, {PDSCH#0,PDSCH#1,…,PDSCH#(K-1)} can be combined to generate one bundled HARQ-ACK, and {PDSCH#(K),PDSCH#(K+1),…,PDSCH#(2*K-1)} can be combined to generate one bundled HARQ-ACK. Continuing this process, {PDSCH#(floor(M / K)*K),PDSCH#(floor(M / K)*K+1),…,PDSCH#(M-1)} can be combined to generate one bundled HARQ-ACK. As a result, a total of N group Bundled HARQ-ACK bits may be generated.

[0264] As a second method, group PDSCH in chronological order N group It is possible to create groups of this size. The number of PDSCH units in each group is given by ceil(M / N). group ) or floor(M / N group There may be ) items. In chronological order, ceil(M / N group ) PDSCHs combined into M mod N group Create individual groups, and then, in chronological order, floor(M / N group ) PDSCHs are grouped together N group -(M mod N group We can create ) groups. The HARQ-ACKs within a group can be bundled to produce one bundled HARQ-ACK, resulting in a total of N group The bundled HARQ-ACK bits are generated.

[0265] As a third piece of information, the base station can set time intervals for time-domain bundling. These time intervals may be set in slot units. These time intervals can be called bundling windows. N slot Let's assume the terminal is N slotPDSCHs contained in each slot can be grouped together into one group. If there is at least one PDSCH in the group, the terminal can bundle the HARQ-ACKs of the PDSCH into one HARQ-ACK. HARQ-ACKs of groups that do not contain PDSCHs may be set to NACK. Also, HARQ-ACKs of groups that do not contain PDSCHs do not need to be transmitted to the base station. The terminal can then... slot The number of slots can be determined as follows:

[0266] As the first method, the terminal is N consecutive from frame slot 0. slot For each individual slot, the PDSCHs contained within that slot can be grouped together. That is, slot i*N slot Slot i*N slot +1, ..., slot(i+1)*N slot The PDSCH elements included in -1 can be grouped together. Here, i is an integer.

[0267] As a second method, the terminal is connected to the frame slot k, and N slot For each individual slot, the PDSCHs contained within that slot can be grouped together. That is, slot i*N slot +k, slot i*N slot +k+1, ..., slot(i+1)*N slot PDSCHs contained in -1+k can be grouped together. For reference, PDSCHs contained in slot 0, slot 1, ..., slot k-1 can be grouped together into one group. Here, i is an integer. Here, k may be a value set by the base station on the terminal, a value determined based on the index of the slot in which the first PDSCH is scheduled, a value determined based on the index of the slot from which the PDCCH scheduling the PDSCH is transmitted, or a value determined based on the index of the slot from which the PUCCH containing the HARQ-ACK of the PDSCH is transmitted. k is an integer and corresponds to the slot offset.

[0268] For example, let X be a value determined based on the index of the slot in which the first PDSCH is scheduled. Then k = X is acceptable. Since the first PDSCH is scheduled in slot 3, N can be found from slot 3. slot =4 slots, i.e., PDSCHs contained in slots 3, 4, 5, and 6 are grouped together into one group, and the next N slot =The PDSCHs contained in four slots, namely slots 7, 8, 9, and 10, can be grouped together into a single group. k is an integer and corresponds to the slot offset.

[0269] For example, let X be a value determined based on the index of the slot from which the PDCCH that schedules the PDSCH is sent. Then k can be k=X. Since the PDCCH is scheduled for slot 1, from slot 1 to N slot =The PDSCHs contained in the four slots, namely slot 1, slot 2, slot 3, and slot 4, are grouped together into one group, and the next N slot =Four slots, namely slots 5, 6, 7, and 8, can be grouped together into one unit.

[0270] For example, if X is the index of the slot to which a PUCCH containing a PDSCH HARQ-ACK is sent, then k = X mod N slot This is acceptable. Since PUCCH is scheduled for slot 10, k=10 mod 4=2. Therefore, from slot 2 to N slot =The PDSCHs contained in the four slots, namely slots 2, 3, 4, and 5, are grouped together into one group, and then the next N slot =Four slots, namely slots 6, 7, 8, and 9, can be grouped together into one unit.

[0271] Refer to Figure 21 and set the terminal to N slotAssume that =3 is set. Here, k = n-5. That is, bundling windows can be set by grouping three slots together, starting from slot n-5. For example, slots n-5, n-4, and n-3 can be included in bundling window #A, and slots n-2, n-1, and n can be included in bundling window #B. Therefore, one bundled HARQ-ACK bit can be generated by bundling window #A with PDSCHs included in bundling window #A, and one bundled HARQ-ACK bit can be generated by bundling window #B with PDSCHs included in bundling window #B.

[0272] The following describes how a terminal generates a Type-1 HARQ-ACK codebook when time-domain bundling is configured. For illustrative purposes, this invention assumes that the terminal generates groups of PDSCHs based on the first, second, or third information. For convenience, the PDSCHs included in each group are denoted as {PDSCH#n, PDSCH#(n+1), ..., PDSCH#(n+k-1)}. The number of PDSCHs included in each group is k.

[0273] In the present invention, a terminal can select one of the PDSCHs included in a group as a representative. In this case, the terminal can generate a Type-1 HARQ-ACK codebook based on the SLIV corresponding to the PDSCH. The method for selecting one of the PDSCHs included in a group as a representative may include at least one of the following:

[0274] As a first method, one can select the PDSCH that is earliest in time (for example, the one in the first slot) from among the PDSCHs included in the group as the representative. For example, if the PDSCHs included in the group are {PDSCH#n, PDSCH#(n+1), ..., PDSCH#(n+k-1)}, then PDSCH#n can be selected as the representative.

[0275] As a second method, one can select the PDSCH that is slowest in time (for example, the one in the last slot) from among the PDSCHs included in the group as a representative. For example, if the PDSCHs included in the group are {PDSCH#n,PDSCH#(n+1),...,PDSCH#(n+k-1)}, then PDSCH#(n+k-1) can be selected as the representative.

[0276] A third method allows selecting the PDSCH with the most symbols among those included in the group as the representative. If multiple PDSCHs occupy the same number of symbols, the PDSCH with the earliest or latest time interval can be selected as the representative.

[0277] A fourth method allows selecting the PDSCH with the fewest symbols among those included in the group as the representative. If multiple PDSCHs occupy the same number of symbols, the PDSCH with the earliest or latest time interval can be selected as the representative.

[0278] As a fifth method, in the first, second, third, and fourth methods described above, PDSCHs in which at least one symbol overlaps with a symbol configured with UL by a semi-static UL / DL configuration may be excluded.

[0279] Refer to Figure 22, and the terminal receives the second information N slotAssume that =3 is set. Here, k=n-5. That is, a bundling window may be set by grouping three slots together, starting from slot n-5. For example, slots n-5, n-4, and n-3 may be included in bundling window #A, and slots n-2, n-1, and n may be included in bundling window #B. The terminal can select the PDSCH candidate that is slowest in time from among the PDSCH candidates in the bundling window as the representative PDSCH (representative SLIV). For example, if the K1 value is 2 and the TDRA index (or entry) = 3, four PDSCH candidates may be scheduled in slots n-5, n-4, n-3, and n-2. Of these, the first three PDSCH candidates (the PDSCH candidates scheduled in slots n-5, n-4, and n-3) belong to bundling window #A. Therefore, the PDSCH candidate in slot n-3, which is the latest PDSCH candidate in terms of time among the PDSCH candidates, can be selected as the representative PDSCH (representative SLIV). Then, one PDSCH candidate (i.e., the PDSCH candidate scheduled in slot n-2) belongs to bundling window #B. Therefore, the PDSCH candidate in slot n-2, which is the latest PDSCH candidate in terms of time among the PDSCH candidates, can be selected as the representative PDSCH (representative SLIV). The representative PDSCH (representative SLIV) selected in this way is shown in Figure 22.

[0280] In the following description, the selected PDSCH (and its corresponding SLIV) will be referred to as the representative PDSCH (or representative SLIV). One representative PDSCH (or representative SLIV) is determined for each group. The terminal can generate a Type-1 HARQ-ACK codebook based on the representative SLIV as follows:

[0281] 1) Stage 1: Let K1_set be the set of K1 values ​​that can be instructed to the terminal. Based on K1_set and the TDRA table, the terminal can determine the index of the slot in which the representative PDSCH candidate (representative SLIV candidate) is received. In this case, let K_slot be the set of indices of the slots in which the representative PDSCH candidate (representative SLIV candidate) is received.

[0282] 2) Two-step process: The maximum K1 value (hereinafter referred to as K1_max) is extracted from K_slot. After that, the K1_max value is excluded from K_slot.

[0283] 3) Three stages: Let R be the set of representative PDSCH candidates (or representative SLIV candidates) that can be received in slot n-K1_max. If the symbol of a representative PDSCH candidate (or representative SLIV candidate) included in set R overlaps with at least one symbol of a symbol configured as UL in a semi-static UL / DL configuration, then the representative PDSCH candidate (representative SLIV candidate) is excluded from set R.

[0284] The representative PDSCH candidate (or representative SLIV candidate) included in set R can be determined as follows: One K1 value can be selected from K1_set. Let's call this selected K1 value K1_a. Based on the K1_a value and the TDRA table, the terminal can determine the representative PDSCH candidate (or representative SLIV candidate) for slot n-K1_max.

[0285] 4) Four steps: The terminal performs steps A and B for the representative PDSCH candidate (or representative SLIV candidate) included in set R.

[0286] - Step A: A new HARQ-ACK opportunity is assigned to the representative PDSCH candidate (representative SLIV candidate) in set R whose last symbol is the earliest. Then, if there is a representative PDSCH candidate (representative SLIV candidate) in set R whose last symbol overlaps with the earliest representative PDSCH candidate (representative SLIV candidate) by at least one symbol, that representative PDSCH candidate (representative SLIV candidate) is assigned the same HARQ-ACK opportunity. Representative PDSCH candidates (representative SLIV candidates) to which a HARQ-ACK opportunity has been assigned (i.e., (i) the representative PDSCH candidate (representative SLIV candidate) whose last symbol is the earliest representative PDSCH candidate (representative SLIV candidate) and (ii) the representative PDSCH candidate (representative SLIV candidate) whose last symbol overlaps with that representative PDSCH candidate (representative SLIV candidate) by at least one symbol) are removed from set R.

[0287] - Step B: Repeat Step A until the set R becomes an empty set.

[0288] 5) 5 steps: Repeat steps 2 / 3 / 4 until K_slot becomes an empty set.

[0289] 6) Six stages: A terminal can assign B HARQ-ACK bits to a candidate representative PDSCH (or representative SLIV candidate) to which the same HARQ-ACK opportunity has been assigned. Here, B is the maximum number of PDSCHs included in the group that contains the candidate representative PDSCH (or representative SLIV candidate) to which the same HARQ-ACK opportunity has been assigned.

[0290] Refer to Figure 23 for a more detailed explanation. First, let's assume that the representative PDSCH candidate (representative SLIV candidate) has been determined according to Figure 22.

[0291] 1) Stage 1: The terminal has K1 values ​​set to 1 and 2, so K1_set={1,2}. When the K1 value is 2, the representative PDSCH candidate (or representative SLIV candidate) is located in slot n-3 and slot n-2. Therefore, the K1 values ​​of the said slots are 3 and 2. These two values ​​may be included in K_slot. Also, when the K1 value is 1, the representative PDSCH candidate (or representative SLIV candidate) is located in slot n-3 and slot n-1. Therefore, the K1 values ​​of the said slots are 3 and 1. These two values ​​may be included in K_slot. Therefore, when K1_set={1,2} is set, the union of the two is K_slot={1,2,3}.

[0292] 2) Two-step process: Select the maximum value K1_max=3 from K_slot. Then, the K1_max value is excluded from K_slot.

[0293] 3) Three stages: Let R be the set of representative PDSCH candidates (or representative SLIV candidates) that can be received in slot n-K1_max=n-3. If at least one symbol of a representative PDSCH candidate (or representative SLIV candidate) included in set R overlaps with a symbol configured with UL in a semi-static UL / DL configuration, then the representative PDSCH candidate (or representative SLIV candidate) is excluded from set R. For the sake of explanation, in this example, we assume that all symbols in a slot are downlink symbols.

[0294] In slot n-3, the representative PDSCH candidates (or representative SLIV candidates) included in set R are R={(S=0,L=14),(S=0,L=7),(S=7,L=7)}.

[0295] 4) 4 steps: The terminal performs steps A and B for the representative PDSCH candidate (representative SLIV candidate) included in R.

[0296] - Step A: Assign a HARQ-ACK opportunity of 0 to the representative PDSCH candidate (representative SLIV candidate) (S=0,L=7) in set R whose last symbol is the earliest. Then, assign the same HARQ-ACK opportunity to the representative PDSCH candidate (representative SLIV candidate) (S=0,L=14) in set R that overlaps with the aforementioned representative PDSCH candidate (representative SLIV candidate) (S=0,L=7) by at least one symbol. The representative PDSCH candidates (representative SLIV candidates) (S=0,L=7) and (S=0,L=14) to which the HARQ-ACK opportunity has been assigned are removed from set R. Therefore, set R = {(S=7,L=7)}.

[0297] - Step B: Repeat Step A until set R becomes an empty set. In this example, set R is not an empty set, so repeat Step A. Step A assigns HARQ-ACK opportunity 1 to the representative PDSCH candidate (or representative SLIV candidate) (S=7, L=7), and set R becomes an empty set. This completes the 4th stage.

[0298] 5) 5 steps: Repeat steps 2 / 3 / 4 until K_slot becomes an empty set. In the example, K_slot = {2, 1}, so it is not an empty set. Since K_slot is not an empty set, repeat steps 2 / 3 / 4.

[0299] Based on the above steps, the PDSCH candidates and HARQ-ACK opportunities are determined as follows.

[0300] HARQ-ACK opportunity 0: Representative PDSCH candidates for slot n-3 (S=0, L=7), (S=0, L=14)

[0301] HARQ-ACK opportunity 1: Representative PDSCH candidate for slot n-3 (S=7, L=7)

[0302] HARQ-ACK opportunity 2: Representative PDSCH candidates for slot n-2 (S=0, L=7), (S=0, L=14)

[0303] HARQ-ACK opportunity 3: Representative PDSCH candidate for slot n-2 (S=7, L=7)

[0304] HARQ-ACK opportunity 4: Representative PDSCH candidates for slot n-1 (S=0, L=7), (S=0, L=14)

[0305] HARQ-ACK opportunity 5: Representative PDSCH candidate for slot n-1 (S=7, L=7)

[0306] Therefore, a Type-1 HARQ-ACK codebook may consist of six HARQ-ACK opportunities.

[0307] 6) Six stages: The terminal can determine the number of HARQ-ACK bits per HARQ-ACK opportunity as follows: The representative PDSCH candidates included in HARQ-ACK opportunity 0 are (S=0,L=7) and (S=0,L=14), and the TDRA indices (or entries) to which the representative PDSCH candidates belong within the bundling window are 0, 1, 3, 4, 6, 7, 8, and 9 when K1=2, and 3 and 4 when K1=1. Of these, when K1=2 and the TDRA index is 3, there are the most PDSCH candidates in the bundling window, with 3, so HARQ-ACK opportunity 0 contains 3 HARQ-ACK bits. Similarly, HARQ-ACK opportunity 1 may contain 3 HARQ-ACK bits, HARQ-ACK opportunity 2 may contain 1 HARQ-ACK bit, HARQ-ACK opportunity 3 may contain 1 HARQ-ACK bit, HARQ-ACK opportunity 4 may contain 2 HARQ-ACK bits, and HARQ-ACK opportunity 5 may contain 2 HARQ-ACK bits.

[0308] Therefore, a Type-1 HARQ-ACK codebook may contain a total of 12 HARQ-ACK bits.

[0309] Type-2 (or Dynamic) HARQ-ACK Codebook

[0310] A terminal may be configured with a dynamic HARQ-ACK codebook. When a dynamic HARQ-ACK codebook is used, the base station can signal the information necessary for HARQ-ACK codebook generation via the PDCCH (or DCI). Specifically, the base station can signal the information necessary for HARQ-ACK codebook generation via the DAI (Downlink Assignment Index) field of the PDCCH (or DCI). Specifically, the DAI can indicate i) the number of bits in the HARQ-ACK codebook, and / or ii) information regarding the position of the HARQ-ACK bit corresponding to the DAI within the HARQ-ACK codebook. Here, the HARQ-ACK bit corresponding to the DAI can mean (i) the HARQ-ACK bit for the PDSCH scheduled by the DAI, or (ii) the HARQ-ACK bit for the DAI. The DAI can be distinguished into counter-DAI and total-DAI. The terminal can determine the number of bits in the dynamic HARQ-ACK codebook based on the DAI of PDCCH (or DCI).

[0311] On the other hand, a Type-2 HARQ-ACK codebook may consist of two subcodebooks. The information necessary for constructing each subcodebook (for example, the subcodebook size (e.g., number of bits), the HARQ-ACK bit positions within the subcodebook) may be obtained based on the DAI information within each DCI.

[0312] The first subcodebook contains the HARQ-ACK bits for PDSCHs with TB-based transmission. Here, each PDSCH is scheduled by each DCI; that is, one PDSCH is scheduled by one DCI (hereinafter referred to as single PDSCH scheduling). Furthermore, if a PDSCH with TB-based transmission is configured to contain one TB, one HARQ-ACK bit is generated per PDSCH, and if it is configured to contain two TBs in at least one cell (and spatial bundling is not configured), two HARQ-ACK bits may be generated per PDSCH. Therefore, (if spatial bundling is not configured) P HARQ-ACK bits may be generated per DCI that schedules TB-based transmission, where P is the maximum number of TBs included in the PDSCH. For reference, if the number of TBs scheduled by a DCI is less than P, the HARQ-ACK bits corresponding to the missing TBs (i.e., unscheduled TBs) are set to NACK.

[0313] The second subcodebook includes the HARQ-ACK bit of the PDSCH transmitted via CBG (code block group). The terminal has up to N PDSCHs transmitted via CBG in cell c per TB. CBG,c It may be configured to include CBGs. For all cells where CBG-based transmission is configured, (maximum TB of cell c)*N CBG,c The maximum value is N CBG,max Let's assume that the terminal schedules N CBG-based transmissions per DCI. CBG,max Generates HARQ-ACK bits. For reference, the number of CBGs scheduled in DCI is N. CBG,max If the number is less than the required number of CBGs, the HARQ-ACK bits corresponding to the missing CBGs will be set to NACK.

[0314] The following describes how to generate a Type-2 HARQ-ACK (sub)codebook when multiple PDSCHs are scheduled on a single DCI (i.e., multi-slot scheduling; multi-PDSCH scheduling). For the sake of explanation, in the following description, the second subcodebook is assumed to include both CBG-based HARQ-ACK bits and multi-PDSCH scheduling-based HARQ-ACK bits. However, this is merely an example, and in actual wireless communication environments, depending on the scheduling situation, the second subcodebook may include only multi-PDSCH scheduling-based HARQ-ACK bits. As a first method, when multiple PDSCHs are scheduled on a single DCI, the HARQ-ACK for multi-PDSCH may always be transmitted in the second subcodebook. Here, the second subcodebook may be modified as follows:

[0315] The second subcodebook includes (i) the HARQ-ACK bit of a PDSCH transmitted via CBG-based transmission, and (ii) the HARQ-ACK bit of multiple PDSCHs when multiple PDSCHs are scheduled in a single DCI. The terminal transmits up to N PDSCHs per TB to cell c via CBG-based transmission. CBG,c It may be configured to include CBGs. For all cells where CBG-based transmission is configured, (maximum TB of cell c) * N CBG,c The maximum value is N CBG,max Let's assume that. Also, when multiple PDSCHs are scheduled in one DCI, the maximum value of the number of PDSCHs scheduled by one TDRA index is N. multi-PDSCH,max Let's go with that.

[0316] The terminal instructs CBG-based transmission to send a maximum of (N) per DCI. CBG,max ,N multi-PDSCH,max )HARQ-ACK bits can be generated. The terminal can set max(N) for DCI to instruct multi-PDSCH scheduling. CBG,max ,N multi-PDSCH,max)HARQ-ACK bits can be generated. Assuming the number of CBGs scheduled in DCI is max(N CBG,max ,N multi-PDSCH,max If the number of PDSCHs scheduled by DCI instructing multi-PDSCH scheduling is less than max(N), the HARQ-ACK bits corresponding to the missing (CBG) number are set to NACK. CBG,max ,N multi-PDSCH,max If the number is less than the number of missing (PDSCH) bits, the HARQ-ACK bits corresponding to the missing number will be set to NACK.

[0317] As a second method, when multiple PDSCHs are scheduled on a terminal with a single DCI, the HARQ-ACK for multiple PDSCHs may be selectively transmitted using either a first subcodebook or a second subcodebook, depending on the number of PDSCHs. Here, the first and second subcodebooks may be modified as follows:

[0318] The first subcodebook may include (i) the HARQ-ACK bit for PDSCHs with TB-based transmission, and (ii) the HARQ-ACK bit for PDSCHs when multiple PDSCHs are scheduled in a single DCI (i.e., multi-PDSCH), provided that the number of PDSCHs is X or less. Let's assume that a PDSCH with TB-based transmission is configured to contain P TBs, where P is the maximum number of TBs included in the PDSCH. Therefore, max{P,X} HARQ-ACK bits may be generated for each DCI that schedules TB-based transmission. For reference, if the number of TBs scheduled in a DCI is less than max{P,X}, the HARQ-ACK bits corresponding to the number of missing (PDSCHs) are set to NACK. For reference, a DCI that instructs multi-PDSCH scheduling will schedule X or fewer PDSCHs. If the number of PDSCHs scheduled by a DCI instructing multi-PDSCH scheduling is less than max{P,X}, the HARQ-ACK bits corresponding to the number of missing PDSCHs will be set to NACK.

[0319] The second subcodebook includes (i) the HARQ-ACK bit of the PDSCH transmitted via CBG-based transmission, and (ii) the HARQ-ACK bit of the multiple PDSCHs when multiple PDSCHs are scheduled in DCI and the number of such PDSCHs exceeds X. The terminal receives up to N PDSCHs per TB transmitted via CBG-based transmission to cell c. CBG,c It may be set to include this number of CBGs. For all cells where CBG-based transmission is set, (maximum TB of cell c) * N CBG,c The maximum value is N CBG,max Let's assume that when multiple PDSCHs are scheduled in DCI, the maximum number of PDSCHs scheduled by a single TDRA index is N. multi-PDSCH,max Let's assume that. For reference, N multi-PDSCH,max This value is greater than X.

[0320] The terminal instructs CBG-based transmission to send a maximum of (N) per DCI. CBG,max ,N multi-PDSCH,max ) Generates a HARQ-ACK bit. The terminal directs the DCI to the multi-PDSCH scheduling to max(N CBG,max ,N multi-PDSCH,max ) Generates HARQ-ACK bits. The number of CBGs that DCI schedules is max(N CBG,max ,N multi-PDSCH,max If the number of PDSCHs scheduled by the DCI instructing multi-PDSCH scheduling is less than (N), the HARQ-ACK bits corresponding to the missing (CBG) number are set to NACK. CBG,max ,N multi-PDSCH,max If the number is less than the number of missing (PDSCH) bits, the HARQ-ACK bits corresponding to the missing number will be set to NACK.

[0321] In the above, X may preferably be defined as P. That is, when a multi-PDSCH scheduling DCI schedules fewer than or equal to P PDSCHs, the HARQ-ACK of the multi-PDSCH is included in the first subcodebook, and when a multi-PDSCH scheduling DCI schedules more than P PDSCHs, the HARQ-ACK of the multi-PDSCH is included in the second subcodebook.

[0322] The second method may be modified as follows when the Type-2 HARQ-ACK codebook and time-domain bundling are configured simultaneously. Time-domain bundling is as described above.

[0323] As a modified second method, when multiple PDSCHs are scheduled for a terminal with a single DCI, the HARQ-ACK for multiple PDSCHs may be selectively transmitted by the first or second subcodebook depending on the number of bundled HARQ-ACK bits by the DCI. The number of bundled HARQ-ACK bits is determined by the number of PDSCHs / bundling groups. Here, the first and second subcodebooks may be modified as follows:

[0324] The first subcodebook includes (i) the HARQ-ACK bits of a PDSCH with TB-based transmission, and (ii) the bundled HARQ-ACK bits if the bundled HARQ-ACK by the DCI is X bits or less when multiple PDSCHs are scheduled by a single DCI. Here, let's assume that a PDSCH with TB-based transmission is configured to contain (maximum) P TBs, where P is the maximum number of TBs included in the PDSCH. Therefore, max{P,X}HARQ-ACK bits may be generated for each DCI that schedules TB-based transmission. For reference, if the number of TBs scheduled by the DCI is less than max{P,X}, the HARQ-ACK bits corresponding to the missing number of (TBs) are set to NACK. max{P,X}bundled HARQ-ACK bits may be generated for each DCI that schedules TB-based transmission. For reference, a DCI that instructs multi-PDSCH scheduling corresponds to bundled HARQ-ACK bits of X bits or less. If the number of bundled HARQ-ACK bits corresponding to DCIs that instruct multi-PDSCH scheduling is less than max{P,X}, then the bundled HARQ-ACK bits corresponding to the missing (PDSCH) will be set to NACK.

[0325] The second subcodebook includes (i) the HARQ-ACK of a PDSCH transmitted via CBG, and (ii) the bundled HARQ-ACK bit when multiple PDSCHs are scheduled by DCI and the bundled HARQ-ACK by DCI exceeds X bits. The terminal receives up to N PDSCHs per TB transmitted via CBG for cell c. CBG,c It may be set to include this number of CBGs. For all cells where CBG-based transmission is set, (maximum TB of cell c) * N CBG,c The maximum value is N CBG,max Let's assume that when multiple PDSCHs are scheduled in DCI, the maximum value of the number of bundled HARQ-ACK bits corresponding to one TDRA index is N. bundled,max Let's assume that. For reference, Nbundled,max This value is greater than X.

[0326] The terminal instructs the CBG-based transmission to send a maximum of (N) DCI per DCI. CBG,max ,N bundled,max )HARQ-ACK bits can be generated. The terminal can set max(N) for DCI to instruct multi-PDSCH scheduling. CBG,max ,N bundled,max ) Generates HARQ-ACK bits. Assuming the number of CBGs scheduled in DCI is max(N CBG,max ,N bundled,max If the number of bundled HARQ-ACK bits corresponding to the missing (CBG) is less than (max(N), the HARQ-ACK bits corresponding to the missing (CBG) will be set to NACK. CBG,max ,N bundled,max If the number is less than the number of bundled HARQ-ACK bits, the corresponding number of bundled HARQ-ACK bits will be set to NACK.

[0327] For example, suppose a terminal always generates one bundled HARQ-ACK bit for a DCI that instructs multi-PDSCH scheduling. This is the case, for example, when the number of PDSCH / bundling groups for time-domain bundling is set to one. In this case, the bundled HARQ-ACK bit may be included in the first subcodebook (e.g., X=1). In other cases (e.g., when the number of PDSCH / bundling groups for time-domain bundling is multiple), the bundled HARQ-ACK bit may be included in the second subcodebook.

[0328] Figure 24 illustrates an example of the HARQ-ACK codebook transmission process according to one example of the present invention.

[0329] Referring to Figure 24, the terminal can receive single-PDSCH scheduling (S2402). The terminal can also receive multi-PDSCH scheduling (S2404). Here, we assume that TB-based HARQ-ACK feedback is applied to both single- and multi-PDSCH scheduling. The terminal can generate and transmit a Type-2 HARQ-ACK codebook containing HARQ-ACK information for single- and multi-PDSCH scheduling (S2406). The Type-2 HARQ-ACK codebook includes a first subcodebook and may further include a second subcodebook.

[0330] Here, the first subcodebook contains TB-based HARQ-ACK information for single-PDSCH scheduling. TB-based HARQ-ACK information for multi-PDSCH scheduling may be included in the first subcodebook or comprised in the second subcodebook, based on the number of bundled HARQ-ACK bits. For example, if the number of PDSCH / bundling groups for multi-PDSCH scheduling is X or less (e.g., X=1), the TB-based HARQ-ACK information for multi-PDSCH scheduling may be included in the first subcodebook. On the other hand, if the number of PDSCH / bundling groups for multi-PDSCH scheduling exceeds X (e.g., X=1), the TB-based HARQ-ACK information for multi-PDSCH scheduling may be comprised in the second subcodebook. The second subcodebook is concatenated after the first subcodebook.

[0331] Figure 25 is a block diagram showing the configuration of a terminal and a base station according to one embodiment of the present invention. In one embodiment of the present invention, the terminal is embodied in various types of wireless communication devices or computing devices that ensure portability and mobility. The terminal is referred to as UE, STA (Station), MS (Mobile Subscriber), etc. In the embodiment of the present invention, the base station controls and manages cells (e.g., macrocells, femtocells, picocells, etc.) in the service area and performs functions such as signal transmission, channel assignment, channel monitoring, self-diagnosis, and relaying. The base station is referred to as gNB (next Generation NodeB) or AP (Access Point), etc.

[0332] As shown in the figure, a terminal 100 according to one embodiment of the present invention includes a processor 110, a communication module 120, a memory 130, a user interface unit 140, and a display unit 150.

[0333] First, the processor 110 executes various instructions or programs to process data inside the terminal 100. The processor 110 also controls the overall operation of the terminal 100, including each unit, and controls the transmission and reception of data between units. Here, the processor 110 is configured to perform the operations described in the embodiment of the present invention. For example, the processor 110 may receive slot configuration information, determine the slot configuration based on that information, and perform communication according to the determined slot configuration.

[0334] Next, the communication module 120 is an integrated module that performs wireless communication using a wireless communication network and wireless LAN access using a wireless LAN. To this end, the communication module 120 incorporates multiple network interface cards (NICs), such as cellular communication interface cards 121 and 122 and an unlicensed band communication interface card 123, either internally or externally. In the drawing, the communication module 120 is shown as an integrated module, but each network interface card may be arranged independently depending on the circuit configuration or application, contrary to the drawing.

[0335] The cellular communication interface card 121 transmits and receives radio signals to and from at least one of the base station 200, an external device, and a server via a mobile communication network, and provides cellular communication services in a first frequency band based on instructions from the processor 110. According to one embodiment, the cellular communication interface card 121 includes at least one NIC module that utilizes a frequency band of less than 6 GHz. The at least one NIC module of the cellular communication interface card 121 independently performs cellular communication with at least one of the base station 200, an external device, and a server, depending on the cellular communication standard or protocol of the sub-6 GHz frequency band supported by the NIC module.

[0336] The cellular communication interface card 122 uses a mobile communication network to send and receive radio signals with at least one of the base station 200, an external device, or a server, and provides cellular communication services in the second frequency band based on instructions from the processor 110. According to one embodiment, the cellular communication interface card 122 includes at least one NIC module that utilizes a frequency band of 6 GHz or higher. At least one NIC module of the cellular communication interface card 122 independently performs cellular communication with at least one of the base station 200, an external device, or a server, according to the cellular communication standard or protocol of the 6 GHz or higher frequency band supported by the NIC module.

[0337] The unlicensed band communication interface card 123 transmits and receives radio signals to and from at least one of the base station 200, an external device, or a server via the third frequency band, which is an unlicensed band, and provides communication services in the unlicensed band based on instructions from the processor 110. The unlicensed band communication interface card 123 includes at least one NIC module that utilizes the unlicensed band. For example, the unlicensed band may be a 2.4 GHz or 52.6 GHz band. At least one NIC module of the unlicensed band communication interface card 123 independently or dependently performs cellular communication with at least one of the base station 200, an external device, or a server, depending on the unlicensed band communication standard or protocol of the frequency band supported by the NIC module.

[0338] Next, the memory 130 stores control programs used by the terminal 100 and various data associated with them. Such control programs include predetermined programs necessary for the terminal 100 to communicate wirelessly with at least one of the following: a base station 200, an external device, or a server.

[0339] Next, the user interface 140 includes various forms of input / output means provided in the terminal 100. In other words, the user interface unit 140 receives user input using various input means, and the processor 110 controls the terminal 100 based on the received user input. The user interface 140 also outputs based on instructions from the processor 110 using various output means.

[0340] Next, the display unit 150 outputs various images to the display screen. The display unit 150 outputs various display objects, such as content generated by the processor 110 or user interfaces based on control instructions from the processor 110.

[0341] Furthermore, the base station 200 according to the embodiment of the present invention includes a processor 210, a communication module 220, and a memory 230.

[0342] First, the processor 210 executes various instructions or programs to process data within the base station 200. The processor 210 also controls the overall operation of the base station 200, including each unit, and controls the transmission and reception of data between units. Here, the processor 210 is configured to perform the operations described in the embodiment of the present invention. For example, the processor 210 may signal slot configuration information and perform communication according to the signaled slot configuration.

[0343] Next, the communication module 220 is an integrated module that performs wireless communication using a wireless communication network and wireless LAN access using a wireless LAN. To this end, the communication module 220 incorporates multiple network interface cards, such as cellular communication interface cards 221 and 222, and an unlicensed band communication interface card 223, either internally or externally. In the drawings, the communication module 220 is shown as an integrated module, but each network interface card may be arranged independently depending on the circuit configuration or application, contrary to the drawings.

[0344] The cellular communication interface card 221 transmits and receives wireless signals to and from at least one of the terminal 100, external devices, and servers described above using a mobile communication network, and provides cellular communication services in the first frequency band based on instructions from the processor 210. According to one embodiment, the cellular communication interface card 221 includes at least one NIC module that utilizes a frequency band of less than 6 GHz. At least one NIC module of the cellular communication interface card 221 independently performs cellular communication with at least one of the terminal 100, external devices, and servers, depending on the cellular communication standard or protocol of the frequency band of less than 6 GHz supported by the NIC module.

[0345] The cellular communication interface card 222 transmits and receives wireless signals to and from at least one of the terminal 100, an external device, and a server using a mobile communication network, and provides cellular communication services in a second frequency band based on instructions from the processor 210. According to one embodiment, the cellular communication interface card 222 includes at least one NIC module that utilizes a frequency band of 6 GHz or higher. At least one NIC module of the cellular communication interface card 222 independently performs cellular communication with at least one of the terminal 100, an external device, and a server, according to the cellular communication standard or protocol of the 6 GHz or higher frequency band supported by the NIC module.

[0346] The unlicensed band communication interface card 223 uses the third frequency band, which is an unlicensed band, to send and receive wireless signals with at least one of the terminal 100, an external device, or a server, and provides communication services in the unlicensed band based on instructions from the processor 210. The unlicensed band communication interface card 223 includes at least one NIC module that utilizes the unlicensed band. For example, the unlicensed band may be the 2.4GHz or 52.6GHz band. At least one NIC module of the unlicensed band communication interface card 223 independently or dependently performs cellular communication with at least one of the terminal 100, an external device, or a server, depending on the unlicensed band communication standard or protocol of the frequency band supported by the NIC module.

[0347] The terminal 100 and base station 200 shown in Figure 25 are block diagrams according to one embodiment of the present invention, and the separately shown blocks logically distinguish the elements of the device. Therefore, the above-mentioned elements of the device are mounted on one or more chips depending on the device design. In addition, some components of the terminal 100, such as the user interface unit 150 and the display unit 150, may be selectively provided in the terminal 100. Furthermore, the user interface 140 and the display unit 150, etc., may be additionally provided in the base station 200 as needed.

[0348] The above description of the present invention is illustrative, and a person with ordinary skill in the art to which the invention pertains will understand that it can be easily modified into other specific forms without altering the technical idea or essential features of the invention. Therefore, the above embodiments should be understood to be illustrative and not limiting in all respects. For example, each component described as a single form may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined manner.

[0349] The scope of the present invention is indicated by the claims described below rather than by the detailed description above, and all modifications or altered forms derived from the meaning and scope of the claims and the concept of equivalents thereto should be interpreted as being included within the scope of the present invention. [Industrial applicability]

[0350] The present invention is applicable to wireless communication systems. Specifically, the present invention can be used in communication methods and devices used in wireless communication systems. [Explanation of Symbols]

[0351] 100 devices 110 processors 120 Communication Modules 130 memory 140 User Interface Section 150 display units 200 base stations 210 processors 220 Communication Module 230 memory

Claims

1. User equipment configured to operate in a wireless communication system, Communication module and, The communication module includes a processor that controls the communication module, and the processor is Receiving a physical downlink control channel (PDCCH) containing information, wherein the information is Index information pointing to one entry in the TDRA (time-domain resource allocation) table for physical downlink shared channel (PDSCH) allocation, where the TDRA table includes entries indicating multiple slot scheduling information. K for PDSCH-to-HARQ (hybrid automatic repeat and request) slot timing 1 Set {K} 1,i Includes timing information that indicates one value within} (where i represents the index of the element), Receiving and K will be updated 1 The set is K 1 Set {K 1,i }+{d k K 1 This involves updating the set, d k (where k represents the index of the element) represents the slot offset between i) the slot to which the last PDSCH can be assigned based on the multi-slot scheduling information, and ii) the slot to which the kth PDSCH can be assigned based on the multi-slot scheduling information, and is updated. Slot n-K 1,i Determine, for all values in the updated K set, a set R that includes the PDSCH candidate sets receivable in 1 slot n-K, where slot n is indicated using the timing information; With respect to the set R, assign the same HARQ-ACK opportunity to both (i) the first element whose last symbol index is the smallest, and (ii) zero or more second elements that temporally overlap with the first element, and then remove the first element and the zero or more second elements from the set R. Based on the allocated HARQ-ACK opportunity, the system is configured to transmit a semi-static HARQ-ACK codebook via the physical uplink control channel (PUCCH) in slot n. User equipment.

2. The subcarrier spacing (SCS) applied to the downlink slot is the same as the SCS allocated to the uplink slot. User device according to claim 1.

3. The aforementioned wireless communication system includes a 3rd generation partnership project (3GPP®) new radio (NR) based wireless communication system. User device according to claim 1.

4. A method performed by user equipment in a wireless communication system, The step of receiving a physical downlink control channel (PDCCH) containing information, wherein the information is Index information pointing to one entry in the TDRA (time-domain resource allocation) table for physical downlink shared channel (PDSCH) allocation, where the TDRA table includes entries indicating multiple slot scheduling information. K for PDSCH-to-HARQ (hybrid automatic repeat and request) slot timing 1 Set {K} 1,i Includes timing information that indicates one value within} (where i represents the index of the element), The receiving step, K will be updated 1 The set is the aforementioned K1 set {K 1,i }+{d k K 1 A step that sets up the set, d k (where k represents the index of the element) represents an update step in which i) the slot to which the last PDSCH can be assigned based on the multi-slot scheduling information and ii) the slot to which the kth PDSCH can be assigned based on the multi-slot scheduling information is updated, Slot nK 1,i The set R containing the PDSCH candidate set that can be received in the updated K 1 A step of determining all values ​​in a set, wherein slot n is indicated using the timing information, and a step of determining With respect to a set R, the steps include: (i) assigning the same HARQ-ACK opportunity to a first element whose last symbol index is the smallest, and (ii) zero or more second elements that temporally overlap with the first element; and then removing the first element and the zero or more second elements from the set R. The steps include: transmitting a semi-static HARQ-ACK codebook in slot n via the physical uplink control channel (PUCCH) based on the assigned HARQ-ACK opportunity; method.

5. The subcarrier spacing (SCS) applied to the downlink slot is the same as the SCS allocated to the uplink slot. The method according to claim 4.

6. The aforementioned wireless communication system includes a 3rd generation partnership project (3GPP®) new radio (NR) based wireless communication system. The method according to claim 4.

7. A base station configured to operate in a wireless communication system, Communication module and, The communication module includes a processor that controls the communication module, and the processor is Transmitting a physical downlink control channel (PDCCH) containing information, wherein the information is Index information pointing to one entry in the TDRA (time-domain resource allocation) table for physical downlink shared channel (PDSCH) allocation, where the TDRA table includes entries indicating multiple slot scheduling information. K for PDSCH-to-HARQ (hybrid automatic repeat and request) slot timing 1 Set {K} 1,i Includes timing information that indicates one value within} (where i represents the index of the element), Sending and K will be updated 1 The set is K 1 Set {K 1,i }+{d k K 1 This involves updating the set, d k (where k represents the index of the element) represents the slot offset between i) the slot to which the last PDSCH can be assigned based on the multi-slot scheduling information, and ii) the slot to which the kth PDSCH can be assigned based on the multi-slot scheduling information, and is updated. Slot nK 1,i The set R containing the PDSCH candidate set that can be received in the updated K 1 The determination of all values ​​in the set, wherein slot n is indicated using the timing information, With respect to the set R, assign the same HARQ-ACK opportunity to both (i) the first element whose last symbol index is the smallest, and (ii) zero or more second elements that temporally overlap with the first element, and then remove the first element and the zero or more second elements from the set R. Based on the allocated HARQ-ACK opportunity, the system is configured to receive a semi-static HARQ-ACK codebook via the physical uplink control channel (PUCCH) in slot n. Base station.

8. The subcarrier spacing (SCS) applied to the downlink slot is the same as the SCS allocated to the uplink slot. The base station according to claim 7.

9. The aforementioned wireless communication system includes a 3rd generation partnership project (3GPP®) new radio (NR) based wireless communication system. The base station according to claim 7.

10. A method performed by a base station in a wireless communication system, A step of transmitting a physical downlink control channel (PDCCH) containing information, wherein the information is Index information pointing to one entry in the TDRA (time-domain resource allocation) table for physical downlink shared channel (PDSCH) allocation, where the TDRA table includes entries indicating multiple slot scheduling information. K for PDSCH-to-HARQ (hybrid automatic repeat and request) slot timing 1 Set {K} 1,i Includes timing information that indicates one value within} (where i represents the index of the element), The steps to send, K will be updated 1 The set is the aforementioned K1 set {K 1,i }+{d k K 1 A step that sets up the set, d k (where k represents the index of the element) represents an update step in which i) the slot to which the last PDSCH can be assigned based on the multi-slot scheduling information and ii) the slot to which the kth PDSCH can be assigned based on the multi-slot scheduling information is updated, Slot nK 1,i The set R containing the PDSCH candidate set that can be transmitted is the updated K 1 A step of determining all values ​​in a set, wherein slot n is indicated using the timing information, and a step of determining With respect to a set R, the steps include: (i) assigning the same HARQ-ACK opportunity to a first element whose last symbol index is the smallest, and (ii) zero or more second elements that temporally overlap with the first element; and then removing the first element and the zero or more second elements from the set R. The process includes the step of receiving a semi-static HARQ-ACK codebook in slot n via a physical uplink control channel (PUCCH) based on the allocated HARQ-ACK opportunity. method.

11. The subcarrier spacing (SCS) applied to the downlink slot is the same as the SCS allocated to the uplink slot. The method according to claim 10.

12. The aforementioned wireless communication system includes a 3rd generation partnership project (3GPP®) new radio (NR) based wireless communication system. The method according to claim 10.

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