Method for transmitting uplink control information in a wireless communication system, and apparatus using the same

Abstract

To provide a method for efficiently transmitting uplink control information in a wireless communication system and a device using the same.SOLUTION: A base station of a wireless communication system includes a communication module and a processor. When receiving a physical downlink control channel (PDCCH) indicating a change of a downlink (DL) bandwidth part (BWP), the processor is configured to change the DL BWP on the basis of the PDCCH indicating the change of the DL BWP and not include a physical downlink shared channel (PDSCH) scheduled by a PDCCH received before receiving the PDCCH indicating the change of the DL BWP in a PDSCH candidate set, and transmit a semi-static HARQ-ACK codebook including hybrid automatic repeat request (HARQ)-ACK information of the PDSCH corresponding to the PDSCH candidate set to the base station.SELECTED DRAWING: Figure 25

Description

Technical Field

[0001] The present invention relates to a wireless communication system. Specifically, the present invention relates to uplink control information transmission in a wireless communication system and an apparatus using the same.

Background Art

[0002] After the commercialization of the fourth-generation (4G) communication system, efforts have been made to develop a new fifth-generation (5G) communication system to meet the increasing demand for wireless data traffic. The 5G communication system is called a network communication system beyond 4G, a post-LTE system, or a new radio (NR) system. In order to achieve high-speed data transfer rates, the 5G communication system includes systems operated using millimeter wave (mmWave) bands of 6 GHz or higher, and from the perspective of ensuring coverage, also includes communication systems operated using frequency bands of 6 GHz or lower. Therefore, implementation forms in base stations and terminals are being considered.

[0003] The 3rd Generation Partnership Project (3GPP (registered trademark)) NR system enhances the spectral efficiency of the network and enables communication providers to offer more data and voice services through a given bandwidth. Therefore, the 3GPP NR system is designed to meet the demands for high-speed data and media transmission in addition to supporting a large amount of voice. The advantages of the NR system are to achieve higher throughput and lower latency on the same platform, support frequency division duplexing (FDD) and time division duplexing (TDD), and provide a low operating cost with an improved end-user environment and a simple architecture.

[0004] For more efficient data processing, the dynamic TDD of the NR system may use a method to change the number of orthogonal frequency division multiplexing (OFDM) symbols that can be used in the uplink and downlink according to the data traffic direction of cell users. For example, if the downlink traffic of a cell is larger than the uplink traffic, the base station may allocate a plurality of downlink OFDM symbols to a slot (or subframe). Information regarding the slot configuration needs to be transmitted to the terminal.

[0005] In order to reduce the path loss of radio waves and increase the transmission distance of radio waves in the millimeter wave band, in the 5G communication system, beamforming, massive multiple-input / multiple-output (massive MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, hybrid beamforming combining analog beamforming and digital beamforming, and massive antenna technology are being discussed. Furthermore, for the network improvement of the system, in the 5G communication system, evolved small cells, advanced small cells, cloud radio access network (cloud RAN), ultra-high density networks, device-to-device communication (D2D), vehicle-to-vehicle / road-to-vehicle communication (V2X), wireless backhaul, non-terrestrial network communication (NTN), mobile networks, cooperative communication, multi-point cooperation (CoMP), interference cancellation, etc. are being developed. Furthermore, in the 5G system, hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC), which are advanced coding modulation (ACM) schemes, and filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA), which are advanced connection technologies, are under development.

[0006] On one hand, in a human-centric connection network where humans generate and consume information, the Internet has evolved into an Internet of Things (IoT) network that exchanges information among distributed components such as objects. Internet of Everything (IoE) technology, which combines IoT technology with big data processing technology through connection to cloud servers, has also emerged. To realize IoT, technical elements such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology are required. Therefore, in recent years, technologies such as sensor networks, machine-to-machine (M2M), and machine type communication (MTC) have been studied for connecting objects. In an IoT environment, intelligent Internet technology (IT) services that collect and analyze data generated from connected objects can be provided to create new value for people's lives. Through the integration and hybridization of existing information technology (IT) with various industries, IoT can be 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.

[0007] Therefore, various attempts have been made to apply the 5G communication system to the IoT network. For example, technologies such as sensor networks, machine-to-machine (M2M), and machine type communication (MTC) are implemented by techniques such as beamforming, MIMO, and array antennas. The application of cloud RAN as the above-mentioned big data processing technology is an example of the integration of 5G technology and IoT technology. Generally, mobile communication systems have been developed to provide voice services while ensuring user activities.

[0008] However, in mobile communication systems, not only voice but also data services are gradually expanding and have now evolved to provide high-speed data services. However, in currently deployed mobile communication systems, due to resource shortages and users' demand for high-speed services, more advanced mobile communication systems are required.

Summary of the Invention

Problems to be Solved by the Invention

[0009] An object of an embodiment of the present invention is to provide a method and an apparatus for efficiently transmitting signals in a wireless communication system. Another object of an embodiment of the present invention is to provide a method for transmitting uplink control information in a wireless communication system and an apparatus using the same.

Means for Solving the Problems

[0010] A user equipment of a wireless communication system according to an embodiment of the present invention includes a communication module and a processor configured to control the communication module. When the processor receives a physical downlink control channel (PDCCH) indicating a change in a downlink (DL) bandwidth part (BWP), the processor changes the DL BWP based on the PDCCH indicating the change in the DL BWP, and does not include a physical downlink shared channel (PDSCH) scheduled by a PDCCH received before receiving the PDCCH indicating the change in the DL BWP in a PDSCH candidate set, and transmits a semi-static hybrid automatic repeat request (HARQ)-ACK codebook including HARQ-ACK information of a physical downlink shared channel (PDSCH) corresponding to the PDSCH candidate set to a base station of the wireless communication system.

[0011] If the user equipment receives a PDCCH indicating a change in the DL BWP before a predetermined lead time from the start symbol of a physical uplink control channel (PUCCH) transmission including a semi-static HARQ-ACK codebook, the processor may be configured to change the DL BWP and not include in the PDSCH candidate set a PDSCH scheduled by a PDCCH received before receiving the PDCCH indicating the change in the DL BWP.

[0012] The predetermined lead time may be specified by the number of symbols.

[0013] The predetermined lead time may be determined according to the capabilities of the user equipment and the subcarrier spacing.

[0014] If reception of a PDSCH repeated in a plurality of slots is configured, the processor may be configured to determine the PDSCH candidate set based on whether PDSCH reception is available in all of the plurality of slots.

[0015] If the user equipment determines that PDSCH reception is not available in all of the plurality of slots, the user equipment may not include in the PDSCH candidate set the PDSCH repeated in the plurality of slots.

[0016] The processor may be configured to determine the PDSCH candidate set based on whether at least one of the symbols for which PDSCH reception is allocated corresponds to an uplink (UL) symbol.

[0017] If at least one of the symbols for which reception of a first PDSCH is allocated corresponds to a UL symbol, the processor may be configured not to include the first PDSCH in the PDSCH candidate set.

[0018] If at least one of the symbols allocated for receiving the second PDSCH is a symbol used for PRACH transmission, the processor may be configured not to include the second PDSCH in the set of PDSCH candidates.

[0019] If the reception of the PDSCH repeated in multiple slots is configured and the user equipment determines that PDSCH reception is unavailable in all of the multiple slots, the processor may be configured not to include the PDSCH repeated in the multiple slots in the set of PDSCH candidates. If the user equipment determines that PDSCH reception is unavailable in all of the multiple slots, the processor may be configured to determine that the PDSCH reception is unavailable in the corresponding slot if at least one of the symbols allocated for PDSCH reception corresponds to the UL symbol of any one slot.

[0020] The processor may be configured to determine the set of PDSCH candidates based on the time required to process the HARQ-ACK information of the PDSCH.

[0021] If the time required to process the HARQ-ACK information of the third PDSCH is longer than the time from the end of the last symbol of the third PDSCH to the start symbol of the physical uplink control channel (PUCCH) including the semi-static HARQ-ACK codebook, the processor may be configured not to include the third PDSCH in the set of PDSCH candidates.

[0022] The time from the end of the last symbol of the third PDSCH to the start symbol of the PUCCH including the semi-static HARQ-ACK codebook may be determined by the number of symbols.

[0023] A method for operating a user equipment of a wireless communication system according to an embodiment of the present invention includes, when receiving a physical downlink control channel (PDCCH) indicating a change in a downlink (DL) bandwidth part (BWP), changing the DL BWP based on the PDCCH indicating the change in the DL BWP, and not including a physical downlink shared channel (PDSCH) scheduled by a PDCCH received before receiving the PDCCH indicating the change in the DL BWP in a PDSCH candidate set; and transmitting, to a base station of the wireless communication system, a semi-static hybrid automatic repeat request (HARQ)-ACK codebook including HARQ-ACK information of a physical downlink shared channel (PDSCH) corresponding to the PDSCH candidate set.

[0024] The step of not including a PDSCH scheduled by a PDCCH received before receiving the PDCCH indicating the change in the DL BWP in the PDSCH candidate set may include, when the user equipment receives a PDCCH indicating the change in the DL BWP a predetermined lead time before a start symbol of a physical uplink control channel (PUCCH) transmission including the semi-static HARQ-ACK codebook, changing the DL BWP and not including the PDSCH scheduled by the PDCCH received before receiving the PDCCH indicating the change in the DL BWP in the PDSCH candidate set.

[0025] The predetermined lead time may be specified by the number of symbols.

[0026] The predetermined lead time may be determined according to the capabilities of the user equipment and the subcarrier spacing.

[0027] The method may further include determining a PDSCH candidate set based on whether PDSCH reception is available in all of a plurality of slots when reception of the PDSCH repeated in the plurality of slots is configured.

[0028] The method may further include determining a PDSCH candidate set based on whether at least one of the symbols allocated for PDSCH reception corresponds to an uplink (UL) symbol.

[0029] The method may further include determining a PDSCH candidate set based on the time required to process HARQ-ACK information of the PDSCH.

Advantages of the Invention

[0030] One embodiment of the present invention provides a method for efficiently transmitting uplink control information in a wireless communication system and an apparatus using the same.

[0031] The effects that can be obtained from various embodiments of the present disclosure are not limited to the above-described effects, and other effects not described above can be clearly derived and understood by those skilled in the art from the following description.

Brief Description of the Drawings

[0032]

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Embodiments for Carrying Out the Invention

[0033] In this specification, the terms used are general terms that are used as widely as possible considering the functions of the present invention. However, due to the intentions of those skilled in the art, customs, and the emergence of new technologies, the terms may change. Furthermore, in certain cases, there are terms arbitrarily selected by the applicant. In such cases, the meaning thereof will be described in the corresponding explanatory part of the present invention. Therefore, it is intended to clarify that the terms used in this specification should be analyzed based not only on the names of the terms but also on the substantial meanings of the terms and the content throughout this specification.

[0034] Throughout this specification and the following claims, when an element is described as "connected" to another element, that element may be "directly connected" to the other element or "electrically connected" to the other element through a third element. Furthermore, unless explicitly stated to the contrary, the word "comprise" means including the recited elements, but without excluding any other elements unless specifically stated. Additionally, in some exemplary embodiments, limitations such as "more than or equal to" or "less than or equal to" based on certain thresholds can be appropriately replaced with "more than" or "less than", respectively.

[0035] The following techniques can be used in various wireless access systems such as code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier FDMA (SC-FDMA), etc. CDMA can be implemented by wireless technologies such as universal terrestrial radio access (UTRA) or CDMA2000. TDMA can be implemented by wireless technologies such as global system for mobile communications (GSM) / general packet radio service (GPRS) / enhanced data rates for GSM evolution (EDGE). OFDMA can be implemented by wireless technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, evolved UTRA (E-UTRA). UTRA is part of the universal mobile telecommunications system (UMTS). The 3rd Generation Partnership Project (3GPP) long term evolution (LTE) is part of evolved UMTS (E-UMTS) using evolved UTRA terrestrial radio access (E-UTRA), and LTE-advanced (A) is an evolved version of 3GPP LTE. 3GPP new radio (NR) is a system designed separately from LTE / LTE-A, and is a system for supporting extended mobile broadband (eMBB), ultra-reliable and low latency communication (URLLC), and massive machine type communication (mMTC) services which are requirements of IMT-2020. For clarity of explanation, the description will focus on 3GPP NR, but the technical idea of the present invention is not limited thereto.

[0036] Unless otherwise specified in this specification, the base station may include a next-generation node B (gNB) defined in 3GPP NR. Further, unless otherwise specified, the terminal may include a user equipment (UE). Hereinafter, for the sake of understanding the description, each content is described separately by embodiments, but each embodiment may be used in combination with each other. In this specification, the configuration of the UE may indicate the configuration by the base station. More specifically, the base station may configure the value of a parameter used in the operation of the UE or the wireless communication system by transmitting a channel or a signal to the UE.

[0037] FIG. 1 shows an example of a wireless frame structure used in a wireless communication system.

[0038] Referring to FIG. 1, a wireless frame (or radio frame) used in the 3GPP NR system may have a length of 10 ms ((Δf max N f / 100)*T c ). Further, the wireless frame includes 10 subframes (SFs) of the same size. Here, Δf max = 480 * 10 3 Hz, N f = 4096, T c = 1 / (Δf ref * N f,ref ), Δf ref = 15 * 10 3 Hz, and N f,ref = 2048. Numbers from 0 to 9 can be assigned to each of the 10 subframes within one wireless frame. The length of each subframe is 1 ms and may include one or more slots according to the subcarrier spacing. More specifically, in the 3GPP NR system, the subcarrier spacing that can be used is 15 * 2 μ kHz, and μ can have values of μ = 0, 1, 2, 3, 4 as subcarrier spacing configurations. That is, 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz can be used for the subcarrier spacing. One subframe having a length of 1 ms is 2μ In this case, each slot may have a length of 2 -μ ms. 2 μ The slots are 0 to 2 μ-1 In addition, the slots in one subframe can be assigned numbers from 0 to 10*2 μ The time resources may be assigned numbers starting from −1. The time resources may be distinguished by at least one of a wireless frame number (also referred to as a wireless frame index), a subframe number (also referred to as a subframe index), and a slot number (or a slot index).

[0039] FIG. 2 illustrates an example of a downlink (DL) / uplink (UL) slot structure in a wireless communication system. Specifically, FIG. 2 illustrates a resource grid structure for a 3GPP NR system.

[0040] There is one resource grid for each antenna port. Referring to FIG. 2, a slot includes multiple Orthogonal Frequency Division Multiplexing (OFDM) symbols in the time domain and multiple Resource Blocks (RBs) in the frequency domain. OFDM symbol also means one symbol section. Unless otherwise specified, an OFDM symbol may simply be referred to as a symbol. One RB includes 12 consecutive subcarriers in the frequency domain. Referring to FIG. 2, the signal transmitted from each slot is divided into N size,μ grid,x *N RB sc Subcarrier, and N slot symb It can be represented by a resource grid containing OFDM symbols, where x=DL if the signal is a DL signal and x=UL if the signal is a UL signal. N size,μ grid,x represents the number of resource blocks (RBs) according to the subcarrier spacing component μ (x is DL or UL), and N slot symb N represents the number of OFDM symbols in a slot. RB scis the number of subcarriers that make up one RB, and N RB sc = 12. The OFDM symbol can be called a cyclic shift OFDM (CP-OFDM) symbol or a discrete Fourier transform spread OFDM (DFT-s-OFDM) symbol according to the multiple access scheme.

[0041] The number of OFDM symbols included in one slot can vary according to the length of the cyclic prefix (CP). For example, in the case of a normal CP, one slot contains 14 OFDM symbols, while in the case of an extended CP, one slot can contain 12 OFDM symbols. In certain embodiments, the extended CP can only be used with a 60 kHz subcarrier spacing. In FIG. 2, for the sake of convenience of explanation, one slot is constituted by 14 OFDM symbols as an example, but the embodiments of the present disclosure can be similarly applied to slots having different numbers of OFDM symbols. Referring to FIG. 2, each OFDM symbol has N size,μ grid,x *N RB sc subcarriers in the frequency domain. The types of subcarriers can be divided into data subcarriers for data transmission, reference signal subcarriers for reference signal transmission, and guard bands. The carrier frequency is also called the center frequency (fc).

[0042] One RB can be defined by N RB sc (e.g., 12) consecutive subcarriers in the frequency domain. For reference, a resource composed of one OFDM symbol and one subcarrier may be called a resource element (RE) or a tone. Therefore, one RB can be composed of N slot symb *N RB sc resource elements. Each resource element in the resource grid can be uniquely defined by a pair of indexes (k, l) within one slot. k is from 0 to N in the frequency domain size,μgrid,x *N RB sc can be an index assigned - 1, and l can be an index assigned - 1 from 0 to N in the time domain. slot symb can be an index assigned - 1.

[0043] For the UE to receive signals from or transmit signals to the base station, the time / frequency of the UE can be synchronized with the time / frequency of the base station. This is because when the base station and the UE are synchronized, the UE can determine the time and frequency parameters necessary to demodulate DL signals and transmit UL signals at the correct time.

[0044] Each symbol of a radio frame used in time - division duplex (TDD) or asymmetric spectrum can be composed of at least one of a DL symbol, a UL symbol, and a flexible symbol. A radio frame used as a DL carrier in frequency - division duplex (FDD) or symmetric spectrum can be composed of a DL symbol or a flexible symbol, and a radio frame used as a UL carrier can be composed of a UL symbol or a flexible symbol. In a DL symbol, DL transmission is possible but UL transmission is not available. In a UL symbol, UL transmission is possible but DL transmission is not available. A flexible symbol can be determined to be used as DL or UL according to a signal.

[0045] Information regarding the type of each symbol, i.e., information representing any one of a DL symbol, a UL symbol, and a flexible symbol, may be constituted by a cell-specific or common Radio Resource Control (RRC) signal. Further, the information regarding the type of each symbol may be further constituted by a UE-specific or dedicated RRC signal. The base station notifies, by using the cell-specific RRC signal, i) the period of the cell-specific slot configuration, ii) the number of slots with only DL symbols from the start of the period of the cell-specific slot configuration, iii) the number of DL symbols from the first symbol of the slot immediately following the slot with only DL symbols, iv) the number of slots with only UL symbols from the end of the period of the cell-specific slot configuration, and v) the number of UL symbols from the last symbol of the slot immediately preceding the slot with only UL symbols. Here, a symbol not constituted by either a UL symbol or a DL symbol is a flexible symbol.

[0046] When the information regarding the symbol type is constituted by a UE-specific RRC signal, the base station may signal whether the flexible symbol is a DL symbol or a UL symbol within the cell-specific RRC signal. In this case, the UE-specific RRC signal cannot change a DL symbol or a UL symbol constituted by the cell-specific RRC signal to another symbol type. The UE-specific RRC signal may signal the number of DL symbols between symbols and the number of UL symbols between the corresponding slots. In this case, the DL symbols of a slot may be continuously constituted by the i-th symbol from the first symbol of the slot. Further, the UL symbols of a slot may be continuously constituted by the last symbol from the j-th symbol of the slot (when i < j). In a slot, a symbol not constituted by either a UL symbol or a DL symbol is a flexible symbol. slot symb The number of DL symbols between symbols, and the N of the corresponding slot slot symb The number of UL symbols between symbols may be signaled. In this case, the DL symbols of a slot may be continuously constituted by the i-th symbol from the first symbol of the slot. Further, the UL symbols of a slot may be continuously constituted by the last symbol from the j-th symbol of the slot (when i < j). In a slot, a symbol not constituted by either a UL symbol or a DL symbol is a flexible symbol.

[0047] The type of symbol composed of the above RRC signal is sometimes called a semi-static DL / UL configuration. In the previous semi-static DL / UL configuration composed of RRC signals, flexible symbols may be indicated as DL symbols, UL symbols, or flexible symbols through the dynamic slot format information (SFI) transmitted on the physical downlink control channel (PDCCH). In this case, the DL symbol or UL symbol composed of the RRC signal is not changed to another symbol type. Table 1 is an example of the dynamic SFI that the base station can indicate to the UE.

[0048]

Table 1

[0049] In Table 1, D indicates a DL symbol, U indicates a UL symbol, and X indicates a flexible symbol. As shown in Table 1, a maximum of two DL / UL switches may be possible in one slot.

[0050] Figure 3 is a diagram for explaining the physical channels used in a 3GPP system (e.g., NR) and a typical signal transmission method using the physical channels.

[0051] When the UE's power is turned on or the UE camps on a new cell, the UE performs an initial cell search (S101). Specifically, the UE may synchronize with the BS in the initial cell search. For this purpose, the UE may receive the primary synchronization signal (PSS) and the secondary synchronization signal (SSS) from the base station to synchronize with the base station and obtain information such as the cell ID. Thereafter, the UE can receive the physical broadcast channel from the base station and obtain the broadcast information within the cell.

[0052] When the initial cell search is completed, the UE receives the Physical Downlink Shared Channel (PDSCH) according to the Physical Downlink Control Channel (PDCCH) and the information therein. Therefore, the UE can obtain system information more specific than the system information obtained through the initial cell search (S102). Here, the system information received by the UE is cell-common system information for the normal operation of the UE at the physical layer in Radio Resource Control (RRC). To refer to the remaining system information or to call System Information Block (SIB) 1.

[0053] When the UE first accesses the base station or does not have radio resources for signal transmission (i.e., the UE in the RRC_IDLE mode), the UE may perform a random access procedure at the base station (Operations S103 to S106). First, the UE transmits a preamble through the Physical Random Access Channel (PRACH) (S103) and can receive a response message for the preamble from the base station through the PDCCH and the corresponding PDSCH (S104). When a valid random access response message is received by the UE, the UE transmits data including the UE identifier, etc., to the base station through the Physical Uplink Shared Channel (PUSCH) indicated by the UL grant transmitted from the base station through the PDCCH (S105). Next, the UE waits for the reception of the PDCCH as an instruction from the base station for collision resolution. When the UE normally receives the PDCCH through the UE identifier (S106), the random access process ends. The UE may obtain UE-specific system information for the normal operation of the UE at the physical layer in the RRC layer during the random access process. When the UE obtains the UE-specific system information, the UE enters the RRC connection mode (RRC_CONNECTED mode).

[0054] The RRC layer is used to generate or manage messages for controlling the connection between the UE and the radio access network (RAN). More specifically, the base station and the UE in the RRC layer broadcast the cell system information required by all UEs in the cell, manage mobility and handover, and may perform storage management including UE measurement reports, UE function management, and device management. Generally, since the update period of the signals distributed in the RRC layer is longer than the transmission time interval (TTI) in the physical layer, the RRC signals are not changed and are maintained for a fairly long interval.

[0055] After the above procedure, the UE receives the PDCCH / PDSCH (S107) and transmits the physical uplink shared channel (PUSCH) / physical uplink control channel (PUCCH) as a general UL / DL signal transmission procedure (S108). Specifically, the UE may receive downlink control information (DCI) through the PDCCH. The DCI may include control information such as resource allocation information for the UE. Also, the format of the DCI may vary depending on the purpose of use. The uplink control information (UCI) transmitted by the UE to the base station through the UL includes DL / UL ACK / NACK signals, channel quality indicator (CQI), precoding matrix index (PMI), rank indicator (RI), etc. Here, the CQI, PMI, and RI may be included in the channel state information (CSI). In the 3GPP NR system, the UE may transmit control information such as the above-mentioned HARQ-ACK and CSI through the PUSCH and / or PUCCH.

[0056] Figure 4 shows the SS / PBCH block for initial cell access in the 3GPP NR system.

[0057] When the power is turned on or when the UE wants to access a new cell, the UE may acquire time and frequency synchronization with the cell and perform an initial cell search procedure. During the cell search procedure, the UE determines the physical cell identity N of the cell cell IDcan be detected. For this purpose, the UE can receive synchronization signals, such as the Primary Synchronization Signal (PSS) and the Secondary Synchronization Signal (SSS), from the base station and synchronize with the base station. In this case, the UE can obtain information such as the cell identity (ID).

[0058] Referring to FIG. 4A, the synchronization signal (SS) will be described in more detail. The synchronization signal can be classified into PSS and SSS. The PSS can be used to obtain time-domain synchronization and / or frequency-domain synchronization, such as OFDM symbol synchronization and slot synchronization. The SSS can be used to obtain frame synchronization and cell group ID. Referring to FIG. 4A and Table 2, the SS / PBCH block can be composed of 20 consecutive RBs (= 240 subcarriers) on the frequency axis and 4 consecutive OFDM symbols on the time axis. In this case, in the SS / PBCH block, the PSS is transmitted in the first OFDM symbol, and the SSS is transmitted in the third OFDM symbol through subcarriers from the 56th to the 182nd. Here, the lowest subcarrier index of the SS / PBCH block is numbered from 0. In the first OFDM symbol where the PSS is transmitted, the base station does not transmit signals through the remaining subcarriers, that is, subcarriers from the 0th to the 55th and from the 183rd to the 239th. Further, in the third OFDM symbol where the SSS is transmitted, the base station does not transmit signals through subcarriers from the 48th to the 55th and from the 183rd to the 191st. The base station transmits the Physical Broadcast Channel (PBCH) through the remaining REs except for the above signals in the SS / PBCH block.

[0059]

Table 2

[0060] SS enables grouping a total of 1008 unique physical layer cell IDs into 336 physical layer cell identifier groups, where each group contains three unique identifiers through combinations of three PSSs and SSSs, specifically such that each physical layer cell ID belongs to only one physical layer cell identifier group. Thus, physical layer cell ID N cell ID = 3N (1) ID + N (2) ID is an index N in the range from 0 to 2 indicating the physical layer identifier within the physical layer cell identifier group (2) ID and an index N in the range from 0 to 335 indicating the physical layer cell identifier group (1) ID by which it can be uniquely defined. The UE can detect the PSS and identify one of the three unique physical layer identifiers. Further, the UE can detect the SSS and identify one of the 336 physical layer cell IDs associated with the physical layer identifier. In this case, the sequence d PSS (n) of the PSS is as follows.

[0061]

Number

[0062] Here, x(i + 7) = (x(i + 4)+x(i)) mod 2, and is given as follows. [x(6) x(5) x(4) x(3) x(2) x(1) x(0)] = [1 1 1 0 1 1 0] Furthermore, the sequence d SSS (n) of the SSS is as follows.

[0063]

Number

[0064] Here, x0(i + 7) = (x0(i + 4)+x0(i)) mod 2 x1(i + 7) = (x1(i + 1) + x1(i)) mod 2 and is given as follows: [x0(6) x0(5) x0(4) x0(3) x0(2) x0(1) x0(0)] = [0 0 0 0 0 0 1] [x1(6) x1(5) x1(4) x1(3) x1(2) x1(1) x1(0)] = [0 0 0 0 0 0 1]

[0065] A radio frame with a length of 10 ms can be divided into two half - frames with a length of 5 ms. Referring to Figure 4B, the slots in each half - frame where the SS / PBCH block is transmitted will be described. The slot where the SS / PBCH block is transmitted can be any one of Cases A, B, C, D, and E. In Case A, the sub - carrier spacing is 15 kHz, and the start point of the SS / PBCH block is the ({2,8}+14 * n)th symbol. In this case, at carrier frequencies below 3 GHz, n = 0 or 1. Further, at carrier frequencies above 3 GHz and less than 6 GHz, n may be 0, 1, 2, 3. In Case B, the sub - carrier spacing is 30 kHz, and the start point of the SS / PBCH block is {4,8,16,20}+28 * n. In this case, at carrier frequencies below 3 GHz, n = 0. Further, at carrier frequencies above 3 GHz and less than 6 GHz, n may be 0, 1. In Case C, the sub - carrier spacing is 30 kHz, and the start point of the SS / PBCH block is the ({2,8}+14 * n)th symbol. In this case, at carrier frequencies below 3 GHz, n = 0 or 1. Further, at carrier frequencies above 3 GHz and less than 6 GHz, n may be 0, 1, 2, 3. In Case D, the sub - carrier spacing is 120 kHz, and the start point of the SS / PBCH block is the ({4,8,16,20}+28 *It is the n-th symbol. In this case, at a carrier frequency of 6 GHz or higher, 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 start point of the SS / PBCH block is ({8, 12, 16, 20, 32, 36, 40, 44}+56 * It is the n-th symbol. In this case, at a carrier frequency of 6 GHz or higher, n = 0, 1, 2, 3, 5, 6, 7, 8.

[0066] FIG. 5 is a diagram showing procedures for transmitting control information and control channels in a 3GPP NR system. Referring to FIG. 5A, a base station may add a cyclic redundancy check (CRC) (e.g., an XOR operation) masked with a radio network temporary identifier (RNTI) to control information (e.g., downlink control information (DCI)) (S202). The base station may scramble the CRC with an RNTI value determined according to the purpose / target of each control information. The common RNTI used by one or more UEs may include at least one of a system information RNTI (SI-RNTI), a paging RNTI (P-RNTI), a random access RNTI (RA-RNTI), and a transmit power control RNTI (TPC-RNTI). Further, the UE-specific RNTI may include at least one of a cell temporary RNTI (C-RNTI) and a CS-RNTI. Thereafter, after performing channel coding (e.g., polar coding) (S204), the base station may perform rate matching according to the amount of resources used for PDCCH transmission (S206). Thereafter, the base station may multiplex the DCI based on a control channel element (CCE)-based PDCCH structure (S208). Further, the base station applies additional processes such as scrambling, modulation (e.g., QPSK), and interleaving to the multiplexed DCI (S210), and then may map the DCI to the resources to be transmitted. A CCE is a basic resource unit for a PDCCH, and one CCE may include a plurality (e.g., six) of resource element groups (REGs). One REG may be composed of a plurality (e.g., twelve) of resource elements (REs). The number of CCEs used for one PDCCH may be defined as an aggregation level. In the 3GPP NR system, aggregation levels of 1, 2, 4, 8, or 16 may be used. FIG. 5B is a diagram related to CCE aggregation level and multiplexing of PDCCH, showing the type of CCE aggregation level used for one PDCCH and the CCEs transmitted in the control area accordingly.

[0067] FIG. 6 shows a control resource set (CORESET) in which a physical downlink control channel (PDCCH) can be transmitted in a 3GPP NR system.

[0068] A CORESET is a time - frequency resource where a PDCCH, i.e., a control signal for a UE, is transmitted. Further, a search space described later may be mapped to one CORESET. Therefore, instead of monitoring all frequency bands for PDCCH reception, a UE can monitor a time - frequency region designated as a CORESET and decode the PDCCH mapped to the CORESET. A base station can configure one or more CORESETS for a UE per cell. A CORESET can be composed of a maximum of three consecutive symbols on the time axis. Further, a CORESET can be composed of units of six consecutive physical resource blocks (PRBs) on the frequency axis. In the embodiment of FIG. 5, CORESET#1 is composed of consecutive PRBs, and CORESET#2 and CORESET#3 are composed of non - consecutive PRBs. A CORESET can be placed in any symbol within a slot. For example, in the embodiment of FIG. 5, CORESET#1 starts at the first symbol of a slot, CORESET#2 starts at the fifth symbol of a slot, and CORESET#9 starts at the ninth symbol of a slot.

[0069] FIG. 7 shows a method for setting a PDCCH search space in a 3GPP NR system.

[0070] To transmit PDCCH to a UE, each CORESET may have at least one search space. In embodiments of the present disclosure, a search space is a set of all time-frequency resources (hereinafter, PDCCH candidates) where PDCCH of a UE can be transmitted. The search space may include a common search space that 3GPP NR UEs are generally required to search, and a UE-specific search space that a specific UE is required to search. In the common search space, a UE may monitor PDCCH that is configured such that all UEs within a cell belonging to the same base station commonly search. Further, the UE-specific search space may be configured for each UE such that the UE monitors PDCCH allocated to each UE at different search space positions according to the UE. In the case of the UE-specific search space, due to the limited control area where PDCCH can be allocated, the search spaces among UEs may be allocated with partial overlap. Monitoring of PDCCH includes blind decoding of PDCCH candidates within the search space. If the blind decoding is successful, it may be expressed that the PDCCH is (successfully) detected / received, and if the blind decoding cannot be performed, it may be expressed that the PDCCH was not detected / was not received, or was not successfully detected / received.

[0071] For convenience of explanation, a PDCCH scrambled with a group common (GC) RNTI known to one or more UEs in advance to transmit DL control information to one or more UEs is called a group common (GC) PDCCH or a common PDCCH. Further, a PDCCH scrambled with a specific terminal RNTI known to a specific UE in advance to transmit UL scheduling information or DL scheduling information to the specific UE is called a specific UE PDCCH. The common PDCCH may be included in the common search space, and the UE-specific PDCCH may be included in the common search space or the UE-specific PDCCH.

[0072] The base station may signal each UE or UE group through the PDCCH about the transmission channels or information (i.e., UL grants) regarding resource allocation for the uplink shared channel (UL-SCH) and hybrid automatic repeat request (HARQ), and about the information (i.e., DL grants) regarding resource allocation for the paging channel (PCH) and downlink shared channel (DL-SCH). The base station may transmit the PCH transport block and DL-SCH transport block through the PDSCH. The base station may transmit data excluding specific control information or specific service data through the PDSCH. Further, the UE may receive data excluding specific control information or specific service data through the PDSCH.

[0073] The base station may transmit the PDCCH, which includes information regarding which UE (one or more UEs) the PDSCH data is transmitted to and how the PDSCH data should be received and decoded by the corresponding UE. For example, assume that the DCI transmitted on a specific PDCCH is CRC masked with the RNTI of "A", and the DCI indicates that the PDSCH is allocated to the radio resource (e.g., frequency position) of "B" and indicates the transmission format information (e.g., transport block size, modulation method, coding information, etc.) of "C". The UE monitors the PDCCH using the RNTI information the UE has. In this case, if there is a UE that performs blind decoding of the PDCCH using the RNTI of "A", the UE receives the PDCCH and receives the PDSCH indicated by "B" and "C" through the received PDCCH information.

[0074] Table 3 shows an embodiment of the physical uplink control channel (PUCCH) used in a wireless communication system.

[0075]

Table 3

[0076] The PUCCH can be used to transmit the following UL control information (UCI). - Scheduling Request (SR): Information used to request UL UL-SCH resources. - HARQ-ACK: Response to the PDCCH (indicating DL SPS release) and / or response to the DL transport block (TB) of the PDSCH. The HARQ-ACK indicates whether the information transmitted on the PDCCH or PDSCH has been received. The HARQ-ACK response includes a positive ACK (simply ACK), a negative ACK (hereinafter, NACK), discontinuous transmission (DTX), or NACK / DTX. Here, the term HARQ-ACK is used interchangeably with HARQ-ACK / NACK and ACK / NACK. Generally, ACK can be represented by a bit value of 1, and NACK can be represented by a bit value of 0. - Channel State Information (CSI): Feedback information regarding the DL channel. The UE generates it based on the CSI-reference signal (RS) transmitted by the base station. The feedback information related to multiple-input multiple-output (MIMO) includes a rank indicator (RI) and a precoding matrix indicator (PMI). The CSI can be divided into CSI part 1 and CSI part 2 according to the information indicated by the CSI.

[0077] In the 3GPP NR system, five PUCCH formats can be used to support various service scenarios, various channel environments, and frame structures.

[0078] PUCCH format 0 is a format that can deliver 1 or 2 bits of HARQ-ACK information or SR. PUCCH format 0 can be transmitted over one or two OFDM symbols on the time axis and one PRB on the frequency axis. If PUCCH format 0 is transmitted in two OFDM symbols, the same sequence on the two symbols can be transmitted over different RBs. In this case, the sequence can be a sequence cyclic shift (CS) from the base sequence used in PUCCH format 0. Through this, the UE can obtain frequency diversity gain. More specifically, the UE can transmit the M bit Bit UCI(M bit = 1 or 2) according to the cyclic shift (CS) value m cs Also, a predetermined CS value m cs A base sequence of length 12 can be transmitted by mapping a cyclic shift sequence based on M bit If M = 1, then one bit UCI 0 and 1 can be mapped to two cyclic shift sequences with a difference of 6 in the cyclic shift value, respectively. bit = 2, then two bits UCI 00, 01, 11, and 10 can be mapped to four cyclic shift sequences with a difference of 3 in the cyclic shift values, respectively.

[0079] PUCCH format 1 may deliver 1 or 2 bits of HARQ-ACK information or SR. PUCCH format 1 may be transmitted over consecutive OFDM symbols on the time axis and one PRB on the frequency axis. Here, the number of OFDM symbols occupied by PUCCH format 1 may be one of 4 to 14. More specifically, M bit The UCI, where M = 1, can be BPSK modulated. The UE can use quadrature phase shift keying (QPSK) to modulate M bitThe UCI with a value of 2 can be modulated. The signal is obtained by multiplying the modulated complex-valued symbol d(0) by a sequence of length 12. In this case, the sequence can be the basic sequence used for PUCCH format 0. To transmit the obtained signal, the UE spreads the even-numbered OFDM symbols to which PUCCH format 1 is allocated through a time-domain orthogonal cover code (OCC). PUCCH format 1 determines the maximum number of different UEs multiplexed in one RB according to the length of the OCC to be used. The demodulation reference signal (DMRS) is spread using the OCC and can be mapped to the odd-numbered OFDM symbols of PUCCH format 1.

[0080] PUCCH format 2 can deliver UCI exceeding 2 bits. PUCCH format 2 can be transmitted through one or two OFDM symbols on the time axis and / or one or more RBs on the frequency axis. When PUCCH format 2 is transmitted in two OFDM symbols, the sequences transmitted in different RBs through the two OFDM symbols can be the same as each other. Here, the sequence can be a plurality of modulated complex-valued symbols d(0),..., d(M symbol- 1). Here, M symbol is M bit / 2. Through this, the UE can obtain a frequency diversity gain. More specifically, the M bit bit UCI (M bit >2) is scrambled at the bit level, QPSK modulated, and mapped to the RBs of one or two OFDM symbols. Here, the number of RBs can be one of 1 to 16.

[0081] PUCCH format 3 or PUCCH format 4 can deliver UCI exceeding 2 bits. PUCCH format 3 or PUCCH format 4 can be transmitted through consecutive 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 can be one of 4 to 14. Specifically, the UE uses π / 2 - Binary Phase Shift Keying (BPSK) or QPSK to generate complex-valued symbols d(0) to d(M symb - 1) to modulate M bit bit UCI (M bit >2). Here, when using π / 2 - BPSK, M symb = M bit , and when using QPSK, M symb = M bit / 2. The UE may not apply block-based spreading to PUCCH format 3. However, the UE can apply block-based spreading to one RB (i.e., 12 subcarriers) using a PreDFT - OCC of length 12 so that PUCCH format 4 can have a multiplexing capacity of 2 or 4. The UE performs transmit precoding (or DFT precoding) on the spread signal and maps it to each RE to transmit the spread signal.

[0082] In this case, the number of RBs occupied by PUCCH format 2, PUCCH format 3, or PUCCH format 4 can be determined according to the length of the UCI transmitted by the UE and the maximum code rate. When the UE uses PUCCH format 2, the UE can transmit HARQ - ACK information and CSI information together through PUCCH. When the number of RBs that the UE can transmit is greater than the maximum number of RBs that PUCCH format 2, or PUCCH format 3, or PUCCH format 4 can use, the UE can transmit only the remaining UCI information without transmitting some UCI information according to the priority of the UCI information.

[0083] PUCCH format 1, PUCCH format 3, or PUCCH format 4 may be configured to indicate frequency hopping within a slot through an RRC signal. When frequency hopping is configured, the index of the RBs to be frequency-hopped may be configured by the RRC signal. When PUCCH format 1, PUCCH format 3, or PUCCH format 4 is transmitted through N OFDM symbols on the time axis, the first hop may have the OFDM symbol at the lower limit (N / 2), and the second hop may have the OFDM symbol at the upper limit (N / 2).

[0084] PUCCH format 1, PUCCH format 3, or PUCCH format 4 may be configured to be repeatedly transmitted in a plurality of slots. In this case, the number of slots K in which the PUCCH is repeatedly transmitted may be configured by the RRC signal. The repeatedly transmitted PUCCH shall start from a fixed OFDM symbol at each slot and have a fixed length. If one OFDM symbol among the OFDM symbols of the slot in which the UE is to transmit the PUCCH is indicated as a DL symbol by the RRC signal, the UE may not transmit the PUCCH in the corresponding slot and delay the transmission of the PUCCH to the next slot to transmit the PUCCH.

[0085] On one hand, in the 3GPP NR system, a UE can perform transmission / reception using a bandwidth that is equal to or less than the bandwidth of a carrier (or cell). For this reason, a UE can receive a bandwidth part (BWP) that is composed of a continuous bandwidth that is a part of the carrier bandwidth. A UE operating according to TDD or operating in an asymmetric spectrum can receive up to four DL / UL BWP pairs on one carrier (or cell). Furthermore, a UE can activate one DL / UL BWP pair. A UE operating according to FDD or operating in a symmetric spectrum can receive up to four DL BWPs on a DL carrier (or cell) and up to four UL BWPs on a UL carrier (or cell). A UE can activate one DL BWP and one UL BWP per carrier (or cell). A UE may not perform reception or transmission in time-frequency resources other than the activated BWP. The activated BWP may be referred to as the active BWP.

[0086] The base station may indicate the activated BWP among the BWPs configured by the UE through downlink control information (DCI). The BWP indicated through DCI is activated, and the other configured BWPs are deactivated. In a carrier (or cell) operating in TDD, the base station may include a bandwidth part indicator (BPI) indicating the BWP to be activated to change the UE's DL / UL BWP pair in the DCI for scheduling the PDSCH or PUSCH. The UE may receive the DCI for scheduling the PDSCH or PUSCH and may identify the activated DL / UL BWP pair based on the BPI. In the case of a DL carrier (or cell) operating in FDD, the base station may include a BPI indicating the BWP to be activated in the DCI for scheduling the PDSCH to change the UE's DL BWP. In the case of a UL carrier (or cell) operating in FDD, the base station may include a BPI indicating the BWP to be activated in the DCI for scheduling the PUSCH to change the UE's UL BWP.

[0087] Figure 8 is a conceptual diagram showing carrier aggregation.

[0088] Carrier aggregation is a method in which a UE uses a plurality of frequency blocks or cells (in a logical sense) composed of UL resources (or component carriers) and / or DL resources (or component carriers) as one large logical frequency band in order for a wireless communication system to use a wider frequency band. One component carrier may also be referred to by terms such as a primary cell (PCell), a secondary cell (SCell), or a primary SCell (PScell). However, hereinafter, for convenience of explanation, the term "component carrier" is used.

[0089] Referring to Figure 8, as an example of a 3GPP NR system, the entire system band may include up to 16 component carriers, and each component carrier may have a bandwidth of up to 400 MHz. A component carrier may include one or more physically contiguous subcarriers. Although Figure 8 shows that each of the component carriers has the same bandwidth, this is merely an example, and each component carrier may have a different bandwidth. Also, although each component carrier is shown to be adjacent to each other on the frequency axis, the drawing is shown as a logical concept, and each component carrier may or may not be physically adjacent to each other.

[0090] Different center frequencies may be used for each component carrier. Also, one common center frequency may be used for physically adjacent component carriers. In the embodiment of Figure 8, assuming that all component carriers are physically adjacent, the center frequency A may be used for all component carriers. Further, assuming that each component carrier is not physically adjacent to each other, the center frequency A and the center frequency B can be used for each of the component carriers.

[0091] When the overall system bandwidth is expanded by carrier aggregation, the frequency bands used for communication with each UE can be defined in terms of component carriers. UE A can use the total system bandwidth of 100 MHz and perform communication using all five component carriers. UE B1 to B5 can only use a bandwidth of 20 MHz and can perform communication using one component carrier. UE C1 and C2 use a 40 MHz bandwidth and can perform communication using two component carriers each. The two component carriers may or may not be logically / physically adjacent. UE C1 represents the case of using two non-adjacent component carriers, and UE C2 represents the case of using two adjacent component carriers.

[0092] FIG. 9 is a diagram for explaining signal carrier communication and multi-carrier communication. Specifically, FIG. 9A shows a single carrier subframe structure, and FIG. 9B shows a multi-carrier subframe structure.

[0093] Referring to FIG. 9A, in the FDD mode, a general wireless communication system can perform data transmission or reception through one DL band and one corresponding UL band. In other specific embodiments, in the TDD mode, the wireless communication system can divide a wireless frame into UL time units and DL time units in the time domain and perform data transmission or reception through the UL / DL time units. Referring to FIG. 9B, three 20 MHz component carriers (CCs) can be aggregated for each of UL and DL so as to support a bandwidth of 60 MHz. Each CC may or may not be adjacent to each other in the frequency domain. FIG. 9B shows a case where the bandwidths of the UL CC and the DL CC are the same and symmetric, but the bandwidth of each CC can be determined independently. Further, asymmetric carrier aggregation with different numbers of UL CCs and DL CCs is possible. The DL / UL CCs allocated / configured to a specific UE through RRC may be referred to as the serving DL / UL CCs of the specific UE.

[0094] The base station can communicate with the UE by activating some or all of the serving CCs of the UE, or by deactivating some CCs. The base station can change the CCs to be activated / deactivated and change the number of CCs to be activated / deactivated. When the base station allocates the CCs available at the UE as cell-specific or UE-specific, at least one of the allocated CCs can be deactivated unless the CC allocation of the UE is completely reconfigured or the UE is handed over. One CC not deactivated by the UE is called the primary CC (PCC) or the primary cell (PCell), and the CCs that the base station can freely activate / deactivate are called the secondary CCs (SCCs) or the secondary cells (SCells).

[0095] On one hand, 3GPP NR uses the concept of cell to manage radio resources. A cell is defined as a combination of DL resources and UL resources, that is, a combination of DL CC and UL CC. A cell can be composed of only DL resources or a combination of DL resources and UL resources. When carrier aggregation is supported, system information may indicate the coordination between the carrier frequency of the DL resources (or DL CC) and the carrier frequency of the UL resources (or UL CC). The carrier frequency refers to the center frequency of each cell or CC. The cell corresponding to the PCC is called the PCell, and the cell corresponding to the SCC is called the SCell. The carrier corresponding to the PCell in DL is the DL PCC, and the carrier corresponding to the PCell in UL is the UL PCC. Similarly, the carrier corresponding to the SCell in DL is the DL SCC, and the carrier corresponding to the SCell in UL is the UL SCC. According to the capabilities of the UE, the serving cell can be composed of one PCell and zero or more SCells. For a UE in the RRC_CONNECTED state that is not configured for carrier aggregation or does not support carrier aggregation, there is only one serving cell composed of only the PCell.

[0096] As described above, the term "cell" used in carrier aggregation is distinguished from the term "cell" that refers to a specific geographical area where communication services are provided by one base station or one antenna group. That is, one component carrier may also be called a scheduling cell, a scheduled cell, a primary cell (PCell), a secondary cell (SCell), or a primary SCell (PScell). However, in order to distinguish between the cell referring to a specific geographical area and the cell of carrier aggregation, in this disclosure, the cell of carrier aggregation is called a CC, and the cell of the geographical area is called a cell.

[0097] FIG. 10 is a diagram showing an example to which a cross-carrier scheduling technique is applied. When cross-carrier scheduling is configured, a control channel transmitted through a first CC may schedule a data channel transmitted through the first CC or the second CC using a carrier indicator field (CIF). The CIF is included in the DCI. In other words, when a scheduling cell is configured, a DL grant / UL grant transmitted in a PDCCH area of the scheduling cell schedules a PDSCH / PUSCH of the scheduled cell. That is, search areas of a plurality of component carriers exist in a PDCCH area of the scheduling cell. The PCell is basically a scheduling cell, and a specific SCell may be designated as a scheduling cell by a higher layer.

[0098] In the embodiment of FIG. 10, it is assumed that three DL CCs are merged. Here, it is assumed that DL component carrier #0 is the DL PCC (or, PCell), and DL component carriers #1 and #2 are DL SCCs (or, SCell). Further, it is assumed that the DL PCC is set as the PDCCH monitoring CC. When cross-carrier scheduling is not configured by UE-specific (or UE-group-specific or cell-specific) upper layer signaling, the CIF becomes invalid, and each DL CC can transmit only the PDCCH to schedule its PDSCH without CIF according to the NR PDCCH rule (non-cross-carrier scheduling, self-carrier scheduling). On the other hand, when cross-carrier scheduling is configured by UE-specific (or UE-group-specific or cell-specific) upper layer signaling, the CIF becomes valid, and a specific CC (for example, the DL PCC) can transmit not only the PDCCH for scheduling the PDSCH of DL CC A using the CIF but also the PDCCH for scheduling the PDSCH of other CCs (cross-carrier scheduling). On the other hand, the PDCCH is not transmitted in other DL CCs. Therefore, the UE monitors the PDCCH without CIF to receive the self-carrier scheduled PDSCH or the PDCCH with CIF to receive the cross-carrier scheduled PDSCH according to whether cross-carrier scheduling is configured for the UE.

[0099] On the other hand, FIGS. 9 and 10 show the subframe structure of the 3GPP LTE-A system, and the same or similar configuration can be applied to the 3GPP NR system. However, in the 3GPP NR system, the subframes in FIGS. 9 and 10 can be replaced with slots.

[0100] FIG. 11 is a block diagram showing the configurations of a UE and a base station according to an embodiment of the present disclosure. In an embodiment of the present disclosure, the UE may be implemented in various types of wireless communication devices or computing devices that are guaranteed to be portable and mobile. The UE may be referred to as a user equipment (UE), a station (STA), a mobile subscriber (MS), etc. Further, in an embodiment of the present invention, the base station controls and manages cells corresponding to service areas (e.g., macro cells, femto cells, pico cells, etc.) and executes functions such as signal transmission, channel assignment, channel monitoring, self-diagnosis, and relaying. The base station may be referred to as a next-generation Node B (gNB) or an access point (AP).

[0101] As shown in the drawings, a UE 100 according to an embodiment of the present disclosure may include a processor 110, a communication module 120, a memory 130, a user interface 140, and a display unit 150.

[0102] First, the processor 110 may execute various instructions or programs within the UE 100 and process data. Further, the processor 110 may control the overall operations including each unit of the UE 100 and control the transmission / reception of data between the units. Here, the processor 110 may be configured to execute operations according to the embodiments described in the present disclosure. For example, the processor 110 may receive slot configuration information, determine a slot configuration based on the slot configuration information, and execute communication according to the determined slot configuration.

[0103] Next, the communication module 120 can be an integrated module that performs wireless communication using a wireless communication network and wireless LAN access using a wireless LAN. For this purpose, the communication module 120 can include, in an internal or external form, a plurality of network interface cards (NICs) such as cellular communication interface cards 121 and 122, and a communication interface card 123 for an unlicensed band. In the drawings, the communication module 120 is shown as an integrated module in one piece. However, different from the drawings, each network interface card can be arranged independently according to the circuit configuration or application.

[0104] The cellular communication interface card 121 can transmit or receive a wireless signal with at least one of the base station 200, an external device, and a server by using a mobile communication network, and provide cellular communication services in a first frequency band based on an instruction from the processor 110. According to one embodiment, the cellular communication interface card 121 can include at least one NIC module that uses a frequency band less than 6 GHz. At least one NIC module of the cellular communication interface card 121 can perform cellular communication independently of at least one of the base station 200, an external device, and a server according to a protocol in a frequency band less than 6 GHz supported by a cellular communication standard or a corresponding NIC module.

[0105] The cellular communication interface card 122 can transmit or receive wireless signals with at least one of the base station 200, an external device, and a server by using a mobile communication network, and can provide cellular communication services in a second frequency band based on instructions from the processor 110. According to one embodiment, the cellular communication interface card 122 may include at least one NIC module that uses a frequency band above 6 GHz. At least one NIC module of the cellular communication interface card 122 can perform cellular communication independently of at least one of the base station 200, an external device, and a server according to a protocol in a frequency band above 6 GHz supported by a cellular communication standard or the corresponding NIC module.

[0106] The non-license communication interface card 123 can transmit or receive wireless signals with at least one of the base station 200, an external device, and a server by using a third frequency band which is an unlicensed band, and provides unlicensed band communication services based on instructions from the processor 110. The non-license band communication interface card 123 may include at least one NIC module that uses an unlicensed band. For example, the unlicensed band may be a 2.4 GHz or 5 GHz band. At least one NIC module of the non-license band communication interface card 123 can perform wireless communication independently or dependently of at least one of the base station 200, an external device, and a server according to an unlicensed band communication standard or protocol of a frequency band supported by the corresponding NIC module.

[0107] The memory 130 stores a control program used in the UE 100 and various data thereof. Such a control program may include a predetermined program necessary to perform wireless communication with at least one of the base station 200, an external device, and a server.

[0108] Next, the user interface 140 includes various input / output means provided in the UE 100. In other words, the user interface 140 can receive user input using various input means, and the processor 110 can control the UE 100 based on the received user input. Further, the user interface 140 can execute an output based on an instruction from the processor 110 using various output means.

[0109] Next, the display unit 150 outputs various images on the display screen. The display unit 150 can output various display objects such as content and user interfaces executed by the processor 110 based on control instructions from the processor 110.

[0110] Furthermore, the base station 200 according to an embodiment of the present disclosure may include a processor 210, a communication module 220, and a memory 230.

[0111] First, the processor 210 can execute various instructions or programs and process internal data of the base station 200. Further, the processor 210 can control the overall operation of the units within the base station 200 and control data transmission and reception between the units. Here, the processor 210 can be configured to execute operations according to the embodiments described in the present disclosure. For example, the processor 210 can signal a slot configuration and execute communication according to the signaled slot configuration.

[0112] Next, the communication module 220 can be an integrated module that performs wireless communication using a wireless communication network and wireless LAN access using a wireless LAN. For this purpose, the communication module 120 can include, in an internal or external form, a plurality of network interface cards such as cellular communication interface cards 221 and 222, and a communication interface card 223 for an unlicensed band. In the drawings, the communication module 220 is shown as an integrated module of one piece. However, different from the drawings, each network interface card can be independently arranged according to circuit configuration or application.

[0113] The cellular communication interface card 221 can transmit or receive a wireless signal with at least one of the base station 100, an external device, and a server by using a mobile communication network, and can provide a cellular communication service in a first frequency band based on an instruction from the processor 210. According to one embodiment, the cellular communication interface card 221 can include at least one NIC module that uses a frequency band less than 6 GHz. At least one NIC module of the cellular communication interface card 221 can perform cellular communication independently of at least one of the base station 100, an external device, and a server according to a protocol in a frequency band less than 6 GHz supported by a cellular communication standard or a corresponding NIC module.

[0114] The cellular communication interface card 222 can transmit or receive wireless signals with at least one of the base station 100, the external device, and the server by using a mobile communication network, and can provide 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 may include at least one NIC module that uses a frequency band of 6 GHz or higher. At least one NIC module of the cellular communication interface card 222 can perform cellular communication independently of at least one of the base station 100, the external device, and the server according to a protocol in a frequency band of 6 GHz or higher supported by the cellular communication standard or the corresponding NIC module.

[0115] The non-license band communication interface card 223 transmits or receives wireless signals with at least one of the base station 100, the external device, and the server by using a third frequency band that is a non-license band, and provides non-license band communication services based on instructions from the processor 210. The non-license band communication interface card 223 may include at least one NIC module that uses a non-license band. For example, the non-license band may be a 2.4 GHz or 5 GHz band. At least one NIC module of the non-license band communication interface card 223 can perform wireless communication independently or dependently of at least one of the base station 100, the external device, and the server according to a non-license band communication standard or protocol in the frequency band supported by the corresponding NIC module.

[0116] FIG. 11 is a block diagram showing UE 100 and base station 200 according to an embodiment of the present disclosure. The blocks shown separately are logically divided elements of the device. Therefore, the above-described elements of the device can be mounted on a single chip or multiple chips according to the design of the device. Further, a part of the configuration of UE 100, for example, user interface 140, display unit 150, etc. can be selectively provided in UE 100. Further, the user interface 140, the display unit 150, etc. can be additionally provided in the base station 200 as necessary.

[0117] The downlink allocation index (DAI) indicates information regarding the number of HARQ-ACKs included in the hybrid automatic repeat request (HARQ)-ACK codebook, which indicates whether a plurality of PDSCHs have been successfully received by the user equipment from the base station. The user equipment may receive the DAI through the PDCCH that schedules the PDSCH. Specifically, the DAI can be divided into a counter DAI and a total DAI. The total DAI indicates the number of PDSCHs transmitted through the same HARQ-ACK codebook. The counter DAI indicates which of the PDSCHs is indicated by the same total DAI. The DCI that schedules the PDSCH may include the value of the counter DAI corresponding to the scheduled PDSCH. Also, the DCI that schedules the PDSCH may include the value of the total DAI corresponding to the scheduled PDSCH.

[0118] FIG. 12 shows the values of the downlink allocation index (DAI) mapped to each component carrier according to an embodiment of the present invention.

[0119] In Fig. 12, the PDCCH that schedules each PDSCH includes a counter-DAI and a total-DAI. The counter-DAI indicates the cumulative number of PDSCHs scheduled in the previous monitoring opportunity and the PDSCHs scheduled from the first component carrier CC#1 to the corresponding component carrier in the current monitoring opportunity. A monitoring opportunity refers to the time interval during which DCI is received on the time axis. Further, the total-DAI indicates the total number of PDSCHs scheduled on all component carriers up to the current monitoring opportunity. The user equipment may determine the order in which the PDSCHs scheduled by the corresponding PDCCH are transmitted by decoding the PDCCH. In this case, the user equipment may transmit the HARQ-ACK of the PDSCH according to the order in which the corresponding PDSCHs are transmitted.

[0120] Referring to FIG. 12, the base station can transmit to a user equipment that can use the PDSCH by aggregating the PDSCH through up to eight component carriers, namely, the first component carrier CC#1, the second component carrier CC#2, the fourth component carrier CC#4, the fifth component carrier CC#5, the sixth component carrier CC#6, and the eighth component carrier CC#8. Since the total number of PDSCHs scheduled on the component carriers is 6, the total DAI value is set to 5. Accordingly, the (counter DAI, total DAI) values of the component carriers such as the first component carrier CC#1, the second component carrier CC#2, the fourth component carrier CC#4, the fifth component carrier CC#5, the sixth component carrier CC#6, and the eighth component carrier CC#8 are set to (0, 5), (1, 5), (2, 5), (3, 5), (4, 5), and (5, 5), respectively. If the user equipment cannot receive the PDCCH transmitted through the fourth component carrier CC#3, the user equipment may determine that it cannot receive one PDCCH (and the corresponding one PDSCH) based on the counter DAI value of the PDCCH transmitted through the second component carrier CC#2 and the counter DAI value of the PDCCH transmitted through the fifth component carrier CC#4. Also, if the user equipment cannot decode the PDCCH transmitted through the eighth component carrier CC#7, the user equipment may determine that although one PDSCH is scheduled after the sixth component carrier CC#5, it is not received normally based on the counter DAI value and the total DAI value of the PDCCH transmitted through the sixth component carrier CC#5.

[0121] In the present invention, a DCI including both a counter DAI and a total DAI is called DCI format A. Further, a DCI including a counter DAI and not including a total DAI is called DCI format B. Since the included DAI differs depending on the DCI format, the base station and the user equipment may be confused about the PDSCH for which ACK / NACK is indicated through the HARQ-ACK codebook. Therefore, a method for preventing this may be required. A method for configuring the total DAI and the counter DAI will be described with reference to FIGS. 13 and 14.

[0122] Each of the total DAI and the counter DAI can be indicated by a 2-bit field. However, embodiments of the present invention can be applied even if each of the total DAI and the counter DAI is indicated by a field of a size different from the 2-bit field. Further, embodiments of the present invention are described through embodiments of transmitting HARQ-ACK information on a TB-based PDSCH transmission. In the following description, unless otherwise specified, it is assumed that the PDSCH includes 1 TB. Further, in the embodiments described below, it is assumed that DCI is transmitted through a plurality of component carriers in one monitoring opportunity. A monitoring opportunity is a time interval for receiving DCI on the time axis. If a total DAI value is included in any DCI, the value of the total DAI transmitted in the monitoring opportunity in which the corresponding DCI is transmitted must be the same as the value of the total DAI of the corresponding DCI. Further, the value of the total DAI can be updated to the latest value every monitoring opportunity.

[0123] FIG. 13 shows DAI values indicated by DCI transmitted from a base station to a user equipment according to an embodiment of the present invention.

[0124] In one embodiment of the present invention, the base station can determine the value of the counter DAI and the value of the total DAI regardless of the DCI format. The base station can set the value of the counter DAI to the number of PDSCHs transmitted from the first component carrier to the current component carrier based on the TB corresponding to the same total DAI. Further, the base station can set the value of the total DAI to the number of PDSCHs transmitted based on the TB corresponding to the total DAI. For example, in FIG. 12(a), three DCI format A transmissions and two DCI format B transmissions are scheduled on eight component carriers. The base station sets the values of the counter DAI and the total DAI of DCI format A transmitted through the first component carrier CC#1 to 1 and 5, respectively. Further, the base station sets the value of the counter DAI of DCI format B transmitted through the second component carrier CC#2 to 2. Further, the base station sets the values of the counter DAI and the total DAI of DCI format A transmitted through the fourth component carrier CC#4 to 3 and 5, respectively. Further, the base station sets the value of the counter DAI of DCI format B transmitted through the second component carrier CC#6 to 4. Further, the base station sets the values of the counter DAI and the total DAI of DCI format A transmitted through the seventh component carrier CC#7 to 5, respectively. In this embodiment, if the user equipment cannot receive all DCI format A, the user equipment cannot determine the total DAI even if the user equipment receives all DCI format B. For example, in FIG. 13(a), when the user equipment cannot receive all DCI format A and the user equipment receives all DCI format B, the user equipment can generate a 4-bit HARQ-ACK codebook to transmit the generated HARQ-ACK codebook to the base station through the PDCCH. Since the base station expects to receive a 5-bit HARQ-ACK codebook, the base station is likely to be unable to receive the HARQ-ACK codebook transmitted by the user equipment.

[0125] In other specific embodiments, the base station may set the value of the counter DAI in different ways according to the DCI format. Within one monitoring opportunity, the counter DAI of DCI format A is first indexed, and the counter DAI of DCI format B is indexed. Specifically, the counter DAI of DCI format A indicates the number of DCI format A and DCI format B transmitted up to the previous monitoring opportunity, and the number of DCI format A transmitted in the corresponding component carrier in the current monitoring opportunity. The counter DAI of DCI format B indicates the number of DCI format A and DCI format B transmitted up to the corresponding monitoring opportunity, all DCI format A in the current monitoring opportunity, and the number of DCI format B included up to the corresponding component carrier in the current monitoring opportunity. The total DAI of DCI format A indicates the number of DCI format A and DCI format B transmitted up to the current monitoring opportunity. The base station may indicate the value of the counter DAI of DCI format B from the value obtained by adding 1 to the total DAI of DCI format A in the monitoring opportunity. In this case, the value of the counter DAI of DCI format B is calculated by incrementing by 1 based on the order of the component carriers. That is, the base station may set the value of the counter DAI of DCI format B to the value obtained by adding the total number of DCI format A to the number of DCI format B from the first component carrier to the component carrier transmitting the corresponding DCI format B. Further, the base station calculates the value of the counter DAI of DCI format A from 1 according to the order of the component carriers. That is, the base station can set the value of the counter DAI to the number of DCI format A from the first component carrier to the component carrier transmitting the corresponding DCI format A. In the above description, the total number of DCI format A indicates the number of DCI format A transmitted up to the current monitoring opportunity.

[0126] For example, in Fig. 13(b), three DCI format A transmissions and two DCI format B transmissions are scheduled on eight component carriers. The first component carrier CC#1 is the component carrier at the most advanced position. Since a DCI that schedules five PDSCHs for the current monitoring opportunity is transmitted, the total DAI value is 5. The base station sets the counter DAI value of DCI format A transmitted through the first component carrier CC#1, which is the component carrier corresponding to the lowest frequency band of DCI format A, to 1. The base station sets the counter DAI value of DCI format A transmitted through the fourth component carrier CC#4, which is the component carrier corresponding to the second lowest frequency band of DCI format A, to 2. The base station sets the counter DAI value of DCI format A transmitted through the seventh component carrier CC#7, which is the component carrier corresponding to the third lowest frequency band of DCI format A, to 3. The base station sets the counter DAI value of DCI format B transmitted through the second component carrier CC#2, which is the component carrier corresponding to the lowest frequency band of DCI format B, to 4. Since three DCI format A transmissions are made, the counter DAI value is set to 4. The base station sets the counter DAI value of DCI format B transmitted through the sixth component carrier CC#6, which is the component carrier corresponding to the second lowest frequency band of DCI format B, to 5. In this embodiment, even if the user equipment cannot receive all DCI format A and also cannot receive all DCI format B, when the user equipment receives at least one DCI format A, the user equipment can obtain the total DAI value. Further, even if the user equipment cannot receive all DCI format A, when the user equipment receives the last DCI format B, the user equipment can determine the total DAI value based on the counter DAI of the last DCI format B.In a specific embodiment, the user equipment may determine the counter DAI received in the last component carrier as the total DAI. For example, in FIG. 12(b), if the user equipment cannot receive all DCI format As and receives the last DCI format B, the user equipment may determine 5, which is the value of the counter DAI of the last DCI format B, as the total DAI. Accordingly, the user equipment may generate a 5-bit HARQ-ACK codebook and transmit the generated HARQ-ACK codebook to the base station through the PUCCH. Since the base station expects to receive a 5-bit HARQ-ACK codebook, the base station can receive the HARQ-ACK codebook transmitted by the user equipment.

[0127] FIG. 14 shows the operation of the user equipment generating a HARQ-ACK codebook according to an embodiment of the present invention.

[0128] The user equipment determines whether the DCI format A that schedules the PDSCH for each component carrier is transmitted in one monitoring opportunity. When the user equipment finds the component carrier in which the DCI format A that schedules the PDSCH is transmitted, the user equipment may generate a HARQ-ACK codebook based on the value of the counter DAI and the total DAI of the DCI (S1401). The user equipment may perform this operation for all component carriers used in one monitoring opportunity. In a specific embodiment, the user equipment increases the index value by 1 from the component carrier with the lowest index and determines whether the DCI format A scheduling the PDSCH is transmitted for each component carrier.

[0129] The user equipment determines whether DCI format B for scheduling PDSCH for each component carrier is transmitted in one monitoring opportunity. When the user equipment finds a component carrier for which DCI format B for scheduling PDSCH is transmitted, the user equipment may generate a HARQ-ACK codebook based on the value of the counter DAI of the corresponding DCI (S1403). The user equipment may perform this operation for all component carriers used in one monitoring opportunity. In a specific embodiment, the user equipment may increment the index value by 1 from the component carrier having the lowest index and determine whether DCI format B scheduling PDSCH is transmitted for each component carrier. When the user equipment receives DCI format A in the previous step (S1401), the user equipment may generate a HARQ-ACK codebook using the total DAI value indicated by DCI format A. If the user equipment does not receive DCI format A in the previous step (S1401), the user equipment may generate a HARQ-ACK codebook based on the maximum value of the counter DAI value indicated by DCI format B discovered by the user equipment. The user equipment may perform the operations of the above two steps (S1401 and S1403) for each new monitoring opportunity.

[0130] The user equipment may piggyback the HARQ-ACK codebook on the PUSCH to transmit the HARQ-ACK codebook. For this purpose, the DCI scheduling the PUSCH may indicate the total DAI value. If CBG-based transmission is not configured at the base station in all component carriers, the total DAI may be indicated by a 2-bit field. When CBG reception is configured on at least one component carrier by the base station, the total DAI may be indicated by a 4-bit field. In this case, the first 2 bits may indicate the total DAI value of the TB-based transmission, and the remaining 2 bits may indicate the value of the total DAI value of the CBG-based transmission. When the user equipment receives a PUSCH including the total DAI, the user equipment may generate the HARQ-ACK codebook using the total DAI value of the corresponding PUSCH.

[0131] The user equipment may not transmit the HARQ-ACK codebook through the PUSCH. That is, the user equipment may generate a 0-bit HARQ-ACK codebook. If CBG-based transmission is not configured at the base station in all component carriers, the total DAI value is indicated as a specific value, and the user equipment has not received any DCI scheduling the PDSCH in the monitoring opportunity, the user equipment may not transmit the HARQ-ACK codebook through the PUSCH. Further, if CBG-based transmission is configured at the base station in at least one component carrier, the total DAI value is indicated as a specific value, and the user equipment has not received any DCI scheduling the PDSCH in the monitoring opportunity, the user equipment may not transmit the HARQ-ACK codebook through the PUSCH. In the above embodiment, the specific value of the total DAI may be 4. In this case, the value of the total DAI field may be 11 b and may be.

[0132] Furthermore, when the TB-based transmission is composed of at least one component carrier by the base station, the total DAI value of the first 2 bits is set to a specific value, the user equipment has not received any DCI for scheduling the TB-based PDSCH in the monitoring opportunity, and the user equipment may not transmit the HARQ-ACK sub-codebook of the TB-based transmission through the PUSCH. In this case, the specific value of the first 2 bits may be 4. In this case, the value of the total DAI field may be 11 b It may be. Furthermore, when the CBG-based transmission is composed of at least one component carrier by the base station, the total DAI value of the last 2 bits is set to a specific value, the user equipment has not received any DCI for scheduling the CBG-based PDSCH in the monitoring opportunity, and the user equipment may not transmit the HARQ-ACK sub-codebook of the CBG-based transmission through the PUSCH. In this case, the specific value of the last 2 bits may be 4. In this case, the value of the total DAI field may be 11 b It may be.

[0133] In an NR wireless communication system, a user equipment may transmit HARQ-ACK information using a semi-static HARQ-ACK codebook. When the semi-static HARQ-ACK codebook is used, the base station may use the RRC signal to configure the length of the HARQ-ACK codebook and each bit of the HARQ-ACK codebook to indicate which PDSCH's ACK / NACK. Therefore, whenever HARQ-ACK codebook transmission is required, it is not necessary for the base station to signal the information required for HARQ-ACK codebook transmission. The set of PDSCHs indicated by the ACK / NACK by the semi-static HARQ-ACK codebook is called the set of PDSCH candidates. Hereinafter, with reference to FIGS. 15 to 25, a method for a user equipment to determine a set of PDSCH candidates will be described.

[0134] The user equipment determines a set of PDSCH candidates based on the information signaled from the base station. In this case, the information signaled from the base station may include K1. K1 indicates the difference between the slot in which the PUCCH is transmitted and the last slot in which the PDSCH is received or scheduled. The fallback DCI may indicate K1 values from 1 to 8. The non-fallback DCI may indicate, as the K1 value, one of up to 8 values configured by the RRC signal. Further, the information signaled from the base station may include K0 and the combination of the start symbol of the PDSCH and the length of the PDSCH. In this case, K0 indicates the difference between the slot in which the PDCCH is received and the slot in which the PDSCH scheduled by the corresponding PDCCH is transmitted. Also, the combination of the start symbol of the PDSCH and the length of the PDSCH may be encoded in the start and length indicator value (SLIV) format. The base station may signal up to 16 K0 values and the combination of the PDSCH start symbol and length. The user equipment may obtain one of the 16 combinations in the DCI that schedules the PDSCH. The user equipment may obtain information regarding the time domain in which the PDSCH is received from the K0 value indicated by the DCI and the PDSCH start symbol and length.

[0135] Furthermore, the information signaled from the base station may include a semi-static DL / UL configuration. The semi-static DL / UL configuration indicates the symbol configuration information of the slots configured through cell-specific RRC signals or UE-specific RRC signals. Specifically, the semi-static DL / UL configuration may indicate whether each symbol included in a slot is a DL symbol, a UL symbol, or a flexible symbol. The user equipment may determine a set of PDSCH candidates based on whether any one of the symbols to which the PDSCH is allocated corresponds to a UL symbol. This is because the PDSCH cannot be received in the symbol corresponding to the UL symbol. In a specific embodiment, when any one of the symbols to which the PDSCH is allocated corresponds to a UL symbol, the user equipment may not include the PDSCH in the set of PDSCH candidates. When none of the symbols to which the PDSCH is allocated corresponds to a UL symbol, the user equipment may include the corresponding PDSCH in the set of PDSCH candidates. This will be described in detail with reference to FIG. 15.

[0136] Furthermore, the information signaled from the base station may include information regarding the configuration of CORESET and search space. The information regarding the set of CORESET and search space may indicate at which position in which slot the PDCCH can be received.

[0137] In addition, the information signaled from the base station may include the PDSCH repetition value. While receiving the PDSCH for each slot, the base station may receive the same PDSCH the number of times indicated by the PDSCH repetition value. In this case, the user equipment may start receiving the PDSCH at the same symbol position within each slot. Further, the user equipment may receive the PDSCH using the same length in each slot. The base station may use the RRC signal to set the PDSCH repetition value to any one of 1, 2, 4, and 8. When the value of PDSCH repetition is greater than 1, it is sometimes called the use of slot aggregation. When the repeated reception of the PDSCH is configured to be repeated in a plurality of slots, the user equipment may determine whether the condition for including the PDSCH in the PDSCH candidate set is satisfied based on whether the PDSCH reception is available in all the slots where the PDSCH is received. Specifically, when the user equipment determines that the PDSCH reception is unavailable in all the slots, it indicates that the PDSCH is repeatedly received. The user equipment may not include the PDSCH in the PDSCH candidate set. In other embodiments, when the PDSCH reception is available in at least one of the slots indicated as the PDSCH reception, the user equipment may include the corresponding PDSCH in the PDSCH candidate set. Embodiments related thereto will be described in detail through the content after FIG. 23.

[0138] FIG. 15 shows the operation of a user equipment determining a PDSCH candidate set according to an embodiment of the present invention.

[0139] The user equipment includes each of the K1 values, as well as the combination of K0 and the PDSCH candidates indicated by the SLIV, in the PDSCH candidate set based on whether the PDSCH candidates indicated by the SLIV are valid for each of the plurality of K1 values and K0 (S1501). For each of the plurality of K1 values and K0, it can be determined whether the PDSCH candidates indicated by the SLIV are valid. If the combination of the corresponding K1 value, K0, and the PDSCH candidates indicated by the SLIV is valid, the user equipment may include the combination of the corresponding K1 value, K0, and the PDSCH candidates indicated by the SLIV in the PDSCH candidate set. For the sake of convenience of explanation, the slot in which the PUCCH is transmitted is called the nth slot. For all of the (n - K1)th slot, (n - K1 - 1)th slot, … and (n - K1 - (N rep - 1))th slots, if any one of the symbols indicated as the symbols in which the PDSCH is allocated by the SLIV corresponds to the UL symbol in the corresponding slot, the user equipment may determine that the PDSCH candidate indicated by the SLIV is not valid for the corresponding K1 value and K0. In this case, N rep indicates the number of slots in which the PDSCH is repeatedly received. As described above, N rep can be configured through the RRC signal. Further, if the PDSCH repetition is not used, it may be N rep = 1. In this case, if any of the symbols indicated by the SLIV as the symbols in which the PDSCH is allocated in the (n - K1)th slot corresponds to the UL symbol, the user equipment may determine that the PDSCH candidate indicated by the SLIV is not valid for the corresponding K1 value and K0. Further, if the search space does not exist in the (n - K1 - (N rep - 1) - K0)th slot, the user equipment may determine that the PDSCH candidate indicated by the SLIV is not valid for the corresponding K1 value and K0. As described above, if the PDSCH repetition is not used, it is N repIt may be equal to 1. Specifically, if all the symbols indicated as the symbols to which PDSCH is allocated by SLIV do not correspond to the UL symbol of any one slot of the (n - K1)-th slot, the (n - K1 - 1)-th slot, … and the (n - K1 - (N rep - 1))-th slot, and if the search space exists in the (n - K1 - (N rep - 1)-K0)-th slot, the user equipment may determine that the PDSCH candidate indicated by SLIV is valid for the corresponding K1 value and K0. If the user equipment determines that the PDSCH candidate indicated by the SLIV value is invalid, the user equipment may not include the combination of the corresponding K1 value, K0, and the PDSCH candidate indicated by SLIV in the PDSCH candidate set. Specifically, a specific method for the user equipment to determine whether the PDSCH candidate is valid will be described with reference to FIGS. 16 to 18.

[0140] FIG. 16 shows a determination as to whether to include, in the PDSCH candidate set, the PDSCH candidate indicated by the SLIV signaled to the user equipment according to an embodiment of the present invention according to K1 and K0.

[0141] In the embodiment of FIG. 16, for all of the (n - K1)-th slot, the (n - K1 - 1)-th slot, … and the (n - K1 - (N rep - 1))-th slot, in the corresponding slot, any one of the symbols indicated by the SLIV to which PDSCH is allocated corresponds to the UL symbol. Therefore, the user equipment determines that the PDSCH candidate indicated by the corresponding K1 value and the SLIV of K0 is invalid. The user equipment does not include the combination of the K1 value, K0, and the PDSCH candidate indicated by SLIV in the PDSCH candidate set.

[0142] Explaining FIG. 15 again.

[0143] The user equipment combines two combinations into one combination (S1503) based on whether the PDSCH candidates of the combination of K1 value, K0, and SLIV included in the PDSCH candidate set and the PDSCH candidates of the combination of other K1 value, K0, and SLIV included in the PDSCH candidate set overlap in at least one symbol of any one slot. The user equipment can determine whether the PDSCH candidates of the combination of K1 value, K0, and SLIV included in the PDSCH candidate set and the PDSCH candidates of the combination of other K1 value, K0, and SLIV included in the PDSCH candidate set overlap in at least one symbol of any one slot. If the PDSCH candidates of the combination of K1 value, K0, and SLIV included in the PDSCH candidate set and the PDSCH candidates of the combination of other K1 value, K0, and SLIV included in the PDSCH candidate set overlap in at least one symbol of any one slot, the user equipment can combine the two combinations into one combination. In a specific embodiment, when the PDSCH candidate set includes N combinations, the user equipment can determine whether the PDSCH candidates of the nth combination overlap with the PDSCH candidates of each of the combinations where m = n + 1,..., N. In this case, the user equipment can sequentially execute the operations related to the overlap determination from n = 0 to n = N - 1.

[0144] The user equipment may determine the position of the HARQ-ACK information of the corresponding PDSCH in the semi-static HARQ-ACK codebook based on the position of the last symbol of the PDSCH included in the PDSCH candidate set. Specifically, the user equipment may determine the position of the bit indicating ACK / NACK of the corresponding PDSCH in the HARQ-ACK codebook according to the position of the last symbol of the PDSCH included in the PDSCH candidate set. Specifically, the position of the HARQ-ACK information of the PDSCH preceding the last symbol may also precede. For example, if the last symbol of the first PDSCH is before the last symbol of the second PDSCH, in the HARQ-ACK codebook, the bit indicating ACK / NACK of the first PDSCH may precede the bit indicating ACK / NACK of the second PDSCH.

[0145] As described above, when any of the symbols to which the PDSCH is allocated corresponds to a UL symbol, the user equipment may not include the PDSCH in the PDSCH candidate set. In this case, the user equipment may further consider at least one of the PRACH and the SS / PBCH. This will be described with reference to FIGS. 17 to 18.

[0146] FIG. 17 shows that the user equipment determines the PDSCH candidate set based on the PRACH set according to an embodiment of the present invention.

[0147] In a 3GPP NR system, a user equipment can perform transmission using random access that uses a Physical Random Access Channel (PRACH) configured by a base station. Specifically, when the PRACH is configured for the user equipment, the user equipment can obtain the remaining minimum system information (RMSI) from the base station. Further, the user equipment can obtain information regarding PRACH transmission parameters from the base station. In this case, the information regarding PRACH transmission parameters may include information regarding at least one of a PRACH preamble, a time resource at which the PRACH is transmitted, and a frequency resource at which the PRACH is transmitted. Further, the user equipment can obtain information regarding the PRACH preamble from the base station. In this case, the information regarding the PRACH preamble may include information regarding at least one of a root sequence of the preamble and a cyclic shift value of the preamble. When semi-static DL / UL is configured for the user equipment, the user equipment can transmit the PRACH only on a UL symbol of a carrier or cell in FR1 (frequency band is 6 GHz or less). Therefore, when a DL symbol or a flexible symbol overlaps with the PRACH, the user equipment may not be able to transmit the PRACH. When semi-static DL / UL is configured for the user equipment, the user equipment can transmit the PRACH on a UL symbol or a flexible symbol of a carrier or cell in FR2 (frequency band is 6 GHz or more). Therefore, when a DL symbol or a flexible symbol overlaps with the PRACH, the user equipment may not be able to transmit the PRACH. Further, when a slot in which PRACH transmission is configured in a carrier or cell in FR2 precedes a slot in which an SS / PBCH block is configured, the user equipment may not transmit the corresponding PRACH. Hereinafter, unless otherwise specified in the description, the symbol used for PRACH transmission means a case where the above conditions are satisfied. When the user equipment determines that PRACH transmission is available on a carrier or cell in FR2, the user equipment can treat a symbol corresponding to the PRACH as a UL symbol.

[0148] If at least one of the symbols allocated for PDSCH is used for RRACH transmission, the user equipment may not include the PDSCH in the PDSCH candidate set. That is, the user equipment may not include the PDSCH that overlaps with the symbol used for PRACH transmission in the PDSCH candidate set. The user equipment may generate a HARQ-ACK codebook except for the bits indicating ACK / NACK of the PDSCH that overlaps with the symbol used for PRACH transmission. If all the symbols allocated for PDSCH are not used for PRACH transmission, the user equipment may include the PDSCH in the PDSCH candidate set.

[0149] In the embodiment of FIG. 17, each symbol corresponding to each PDSCH indicated by SLIV1 and SLIV m overlaps with the flexible symbol. Further, each PDSCH indicated by SLIV1 and SLIV m satisfies the PDSCH candidate set conditions of K0 and K1. The PDSCH indicated by SLIV1 does not overlap with the symbol in which the user equipment can transmit PRACH, but the PDSCH indicated by SLIV m overlaps with the symbol in which the user equipment can transmit PRACH. Therefore, the user equipment includes the PDSCH indicated by SLIV1 in the PDSCH candidate set and does not include the PDSCH indicated by SLIV m in the PDSCH candidate set.

[0150] FIG. 18 shows that a user equipment determines a PDSCH candidate set based on an SS / PBCH block set according to an embodiment of the present invention.

[0151] In the 3GPP NR system, a user equipment can obtain information regarding the reception of the SS / PBCH block of the user equipment from a base station. The base station can configure the user equipment with information for receiving the SS / PBCH block of the user equipment. In this case, the information for SS / PBCH block reception may include the SSB and the SIB1 transmitted in the cell-specific RRC signal. Further, the information for SS / PBCH block reception includes the SSB transmitted in the UE-specific RRC signal. If the user equipment does not receive both the SIB1 with the SSB transmitted and the SSB transmitted from the base station, the user equipment may monitor the SS / PBCH block transmission at a predefined position. If the user equipment receives the SIB1 with the SSB transmitted from the base station but does not receive the SSB transmission, the user equipment may monitor the SS / PBCH block transmission configured by the SSB transmission SIB1. If the user equipment receives the SSB transmission, the user equipment may monitor the SS / PBCH block transmission configured in the SSB transmission. In the following description, the SS / PBCH block transmission may indicate the SS / PBCH block transmission monitored by the user equipment according to the configuration of the base station.

[0152] If the symbol is configured to be used for SS / PBCH transmission to the user equipment, the user equipment may determine that the symbol is a DL symbol. In this case, the symbol used for SS / PBCH block transmission may be configured through a cell-specific RRC signal (e.g., SSB transmission SIB1) or a user equipment-specific RRC signal (e.g., SSB transmission). Even if a PDSCH that overlaps with a UL symbol or a flexible symbol is transmitted within a symbol that overlaps with the symbol used for SS / PBCH block transmission according to a semi-static DL / UL configuration and the PDSCH overlaps with the symbol used for SS / PBCH transmission, the user equipment may include the corresponding PDSCH in the set of PDSCH candidates. Even if a PDSCH that overlaps with a UL symbol or a flexible symbol is transmitted within a symbol that overlaps with the symbol used for SS / PBCH block transmission according to a semi-static DL / UL configuration and the PDSCH overlaps with the symbol used for SS / PBCH transmission, the user equipment may generate a HARQ-ACK codebook by including the bits indicating ACK / NACK of the corresponding PDSCH in the HARQ-ACK codebook. Also, even if a PDSCH that overlaps with the symbol used for PRACH transmission is transmitted within a symbol that overlaps with the symbol used for SS / PBCH block transmission and the PDSCH overlaps with the symbol used for SS / PBCH transmission, the user equipment may include the corresponding PDSCH in the set of PDSCH candidates. That is, even if a PDSCH that overlaps with the symbol used for PRACH transmission is transmitted within a symbol that overlaps with the symbol used for SS / PBCH block transmission and the PDSCH overlaps with the symbol used for SS / PBCH transmission, the user equipment may include the bits indicating ACK / NACK of the corresponding PDSCH in the HARQ-ACK codebook to generate a HARQ-ACK codebook.In the above embodiment, when the PDSCH can be transmitted within a symbol that overlaps with the symbol used for SS / PBCH transmission, all the symbols allocated to the corresponding PDSCH may overlap with the symbol used for SS / PBCH transmission.

[0153] In the embodiment of FIG. 18, all the symbols corresponding to each of the PDSCHs indicated by SLIV1 and SLIV m overlap with the UL symbol. However, all the symbols corresponding to the PDSCH indicated by SLIV m overlap with the symbol used for SS / PBCH transmission. Only some of the symbols corresponding to the PDSCH indicated by SLIV1 overlap with the symbol used for SS / PBCH transmission. Further, each PDSCH indicated by SLIV m satisfies the PDSCH candidate set conditions of K0 and K1. Therefore, the user equipment includes the PDSCH indicated by SLIV m in the PDSCH candidate set and does not include the PDSCH indicated by SLIV1 in the PDSCH candidate set.

[0154] FIGS. 19 to 20 show that, according to an embodiment of the present invention, a user equipment receives a PDSCH and determines a PDSCH candidate set based on the time required to process the HARQ-ACK information of the corresponding PDSCH.

[0155] The user equipment may determine a PDSCH candidate set based on the time required to process the HARQ-ACK information of the PDSCH according to an embodiment of the present invention. The standard of the 3GPP NR system defines the time required for the user equipment to process the HARQ-ACK information of the PDSCH as follows. When the first UL symbol of the PUCCH or PUSCH for transmitting the HARQ-ACK information does not start earlier than symbol L1, the corresponding user equipment needs to transmit valid HARQ-ACK information. Symbol L1 is T after the end of the last symbol of the PDSCH proc,1 =((N1 + d 1,1+d 1,2 )*(2048 + 144)*64*2 ^-μ )*T C is a UL symbol that starts after this. In this case, N1 is μ in Table 4 corresponding to min(μ_DL, μ_UL). μ_DL corresponds to the subcarrier spacing configuration of the DL channel on which the PDSCH is received, and μ_UL corresponds to the subcarrier spacing configuration of the UL channel on which the HARQ-ACK information is transmitted. When the HARQ-ACK information is transmitted through the PUCCH, d 1,1 = 0. When the HARQ-ACK information is transmitted through the PUSCH, d 1,1 = 1. When the user equipment transmits using multiple component carriers (i.e., when carrier aggregation is performed), considering the timing difference between component carriers, the position of the first symbol of the first PUCCH is determined. The mapping type of the PDSCH is type A, and the last symbol of the PDSCH is the i-th symbol in the slot. When i < 7, d 1,2 = 7 - i and d 1,2 = 0. When the mapping type of the PDSCH is type B and the number of PDSCH symbols is 4, d 1,2 = 3. When the mapping type of the PDSCH is type B and the number of PDSCH symbols is 2, d 1,2 = 3 + d. In this case, d is the number of symbols overlapping between the PDCCH that schedules the PDSCH and the corresponding PDSCH. Further, T c is as follows. T C = 1 / (Δf max *N f ), Δf max = 480*103, N f = 4096

[0156]

Table 4

[0157] Unless otherwise specified, in this specification, the fact that the PDSCH processing time condition is not satisfied refers to the case where the first UL symbol of the PUCCH or PUSCH through which the user equipment transmits HARQ-ACK information precedes the L1 symbol. The user equipment may not include a PDSCH that does not satisfy the PDSCH processing time condition in the PDSCH candidate set. That is, the user equipment may generate a HARQ-ACK codebook except for the bits indicating ACK / NACK of a PDSCH that does not satisfy the PDSCH processing time condition.

[0158] In these embodiments, when the user equipment acquires T proc,1 the user equipment may assume that each of d 1,1 and d 1,2 is 0. In other specific embodiments, when the user equipment acquires T proc,1 the user equipment may assume that d 1,1 and d 1,2 have the maximum values that d 1,1 and d 1,2 can respectively have. In other specific embodiments, when the user equipment determines the PDSCH processing time condition, the user equipment may use N1 in Table 4 instead of T proc,1 . In this case, N1 indicates the number of symbols. Unless otherwise specified in this specification, the unit of T proc,1 is ms.

[0159] In the embodiment of FIG. 19, the symbols corresponding to each of the PDSCHs indicated by SLIV1 and SLIV m overlap with the flexible symbols. Also, each PDSCH indicated by SLIV1 and SLIV m satisfies the PDSCH candidate set conditions of K0 and K1. The time (T proc,1) is shorter than the time from the end of the last symbol of the PDSCH to the start of the PUCCH or the start symbol of the PUSCH containing HARQ-ACK information. Therefore, the user equipment includes the PDSCH indicated by SLIV1 in the PDSCH candidate set. SLIV m The time (T proc,1 ) for processing the HARQ-ACK information of the PDSCH indicated by proc,1 is longer than the time from the end of the last symbol of the PDSCH to the start of the PUCCH or the start symbol of the PUSCH containing HARQ-ACK information. Therefore, the user equipment does not include the PDSCH indicated by SLIV m in the PDSCH candidate set.

[0160] In the embodiment of FIG. 20, the user equipment transmits a PUCCH or a PUSCH including HARQ-ACK information in slot n. In this case, four PDSCHs are allocated to the user equipment. The number of symbols from the end of the last symbol of each of the first PDSCH PDSCH candidate #1, the second PDSCH PDSCH candidate #2, and the third PDSCH PDSCH candidate #3 to the start of the start symbol of the PUCCH or PUSCH including HARQ-ACK information is N, that is, the number of symbols derived from T proc,1 is greater than. In this case, N = ceil(T proc,1 / symbol_duration) can be. symbol_duration indicates the length of each symbol. Also, N = N1 can be. N1 can be a value defined in Table 4 above. Further, the number of symbols from the end of the last symbol of each of the fourth PDSCH PDSCH candidate #4 to the start of the start symbol of the PUCCH or PUSCH including HARQ-ACK information is N, that is, the number of symbols derived from T proc,1 is greater than. Therefore, the user equipment includes the first PDSCH PDSCH candidate #1, the second PDSCH PDSCH candidate #2, and the third PDSCH PDSCH candidate #3 in the PDSCH candidate set and does not include the fourth PDSCH PDSCH candidate #4 in the PDSCH candidate set.

[0161] The embodiment described with reference to FIGS. 15 to 16 can be applied to each or some combinations of the embodiments described with reference to FIGS. 17 to 20. This will be described again.

[0162] The user equipment determines a set of PDSCH candidates based on the information signaled from the base station. In this case, the information signaled from the base station may include K1 described above. Further, the information signaled from the base station may include a combination of K0, the start symbol of the PDSCH, and the length of the PDSCH described above. Further, the information signaled from the base station may include the semi-static DL / UL configuration described above. If the symbol is configured to be used for SS / PBCH transmission to the user equipment, the user equipment may determine that the symbol is a DL symbol. In this case, the symbol used for SS / PBCH block transmission may be configured through a cell-specific RRC signal (for example, SSB transmission SIB1) or a UE-specific RRC signal (for example, SSB transmission). Further, the information signaled from the base station may include information regarding the configuration of the CORESET and search space described above. Also, the information signaled from the base station may include the PDSCH repetition value.

[0163] The user equipment determines whether the PDSCH candidate indicated by the SLIV is valid for each of a plurality of K1 values and K0. For the sake of convenience of explanation, the slot in which the PUCCH is transmitted is called the nth slot. If any of the symbols indicated by the SLIV as the symbol in which the PDSCH is allocated in the (n - K1)th slot corresponds to a UL symbol, the user equipment may determine that the PDSCH candidate indicated by the SLIV is not valid for the corresponding K1 value and K0. Further, if the search space does not exist in the (n - K1 - K0)th slot, the user equipment may determine that the PDSCH candidate indicated by the SLIV is not valid for the corresponding K1 value and K0. Further, if the time difference between the last symbol among the symbols corresponding to the PDSCH indicated by the SLIV and the first symbol among the symbols corresponding to the PUCCH or PUSCH in which the HARQ-ACK information is transmitted does not satisfy the PDSCH processing time condition, the user equipment may determine that the PDSCH candidate indicated by the SLIV is not valid for the corresponding K1 value and K0.

[0164] If the user equipment determines that the PDSCH candidate indicated by the SLIV value is invalid, the user equipment may not include the combination of the corresponding K1, K0, and the PDSCH candidate indicated by the SLIV in the PDSCH candidate set. If the user equipment determines that the PDSCH candidate indicated by the SLIV value is valid, the user equipment may include the combination of the corresponding K1 value, K0, and the PDSCH candidate indicated by the SLIV in the PDSCH candidate set.

[0165] The user equipment can determine whether the PDSCH candidates of the combination of K1 value, K0, and SLIV included in the PDSCH candidate set and the PDSCH candidates of the combination of other K1 values, K0, and SLIV included in the PDSCH candidate set overlap in at least one symbol of any one slot. If the PDSCH candidates of the combination of K1 value, K0, and SLIV included in the PDSCH candidate set and the PDSCH candidates of the combination of other K1 values, K0, and SLIV included in the PDSCH candidate set overlap in at least one symbol of any one slot, the user equipment combines the two combinations into one combination.

[0166] The user equipment can determine the position of the HARQ-ACK information of the corresponding PDSCH in the semi-static HARQ-ACK codebook based on the position of the last symbol of the PDSCH included in the PDSCH candidate set. Specifically, the user equipment can determine the position of the bit indicating ACK / NACK of the corresponding PDSCH in the HARQ-ACK codebook according to the position of the last symbol of the PDSCH included in the PDSCH candidate set. Specifically, the position of the HARQ-ACK information of the PDSCH preceding the last symbol may also precede. For example, if the last symbol of the first PDSCH is before the last symbol of the second PDSCH, in the HARQ-ACK codebook, the bit indicating ACK / NACK of the first PDSCH may precede the bit indicating ACK / NACK of the second PDSCH.

[0167] FIG. 21 shows that the user equipment according to an embodiment of the present invention determines a PDSCH candidate set based on a reference PUCCH resource or a reference PUSCH resource.

[0168] As described above, the user equipment may receive the PDSCH and determine whether to include the PDSCH in the PDSCH candidate set based on the time required for HARQ-ACK processing of the PDSCH. A plurality of PUCCH resource sets may be configured for the user equipment. In this case, the user equipment may determine one PUCCH resource set out of the plurality of PUCCH resource sets according to the length of the UCI payload, and transmit the PUCCH using the determined PUCCH resource set. It may be determined according to the value of the PUCCH resource indicator (PRI) field of one PUCCH resource DCI within the PUCCH resource set. The PUCCH resource may be determined by at least the position of the start symbol and the number of symbols. Specifically, the PUCCH resource may be determined by the position of the start symbol, the number of symbols, the start PRB, and the number of PRBs.

[0169] The user equipment may receive the PDSCH and determine whether to include the corresponding PDSCH in the PDSCH candidate set based on the time required for HARQ-ACK processing for the corresponding PDSCH and the reference PUCCH resource or the reference PUSCH resource. The PUCCH resource indicates the resource on which the PUCCH can be transmitted. Further, the PUSCH resource indicates the resource on which the PUSCH can be transmitted. Specifically, the user equipment determines whether to include the corresponding PDSCH in the PDSCH candidate set based on the time difference from the end of the last symbol of the PDSCH received by the user equipment to the start of the first symbol of the reference PUCCH resource or the reference PUSCH resource, and the time required for HARQ-ACK processing of the corresponding PDSCH. In a particular embodiment, if the time difference from the end of the last symbol of the PDSCH received by the user equipment to the start of the first symbol of the PUCCH resource is less than or equal to the time required for HARQ-ACK processing of the corresponding PDSCH, the user equipment may include the corresponding PDSCH in the PDSCH candidate set. For example, if the time difference between the last symbol between the symbols corresponding to the PDSCH indicated by the SLIV and the first symbol between the symbols corresponding to the reference PUCCH or the reference PUSCH on which the HARQ-ACK is transmitted does not satisfy the PDSCH processing time condition, the user equipment may not include the PDSCH candidate indicated by the SLIV in the PDSCH candidate set.

[0170] The reference PUCCH resource can be the PUCCH resource actually used by the user equipment for PUCCH transmission. Specifically, the reference PUCCH resource can be the PUCCH resource indicated by the PRI. Further, the reference PUCCH resource can be the PUCCH resource among the PUCCH resources included in all PUCCH resource sets within one slot, whose starting symbol is the most advanced in time. This is because when the reference PUCCH resource is the PUCCH resource among the PUCCH resources included in all PUCCH resource sets within one slot, whose starting symbol is the most advanced in time, even if the user equipment selects an arbitrary PUCCH resource, the PDSCH processing time condition is satisfied. Further, the reference PUCCH resource can be the PUCCH resource among the PUCCH resources included in all PUCCH resource sets within one slot, whose starting symbol is the latest in time. This is because when the reference PUCCH resource is the PUCCH resource among the PUCCH resources included in all PUCCH resource sets within one slot, whose starting symbol is the most advanced in time, even if the user equipment selects an arbitrary PUCCH resource, the maximum number of PDSCHs can be included in the PDSCH candidate set. In these embodiments, when the length of the semi-static HARQ-ACK codebook is greater than a specific value, the user equipment may exclude the PUCCH resource that transmits UCI with a length less than a specific length from the PUCCH resource set. The length of the HARQ-ACK codebook can indicate the length of the payload of the HARQ-ACK codebook. The specific value can be 2 bits.

[0171] As described above, the HARQ-ACK codebook can be piggybacked on PUSCH transmissions. In this case, the user equipment may determine whether the PDSCH is included in the PDSCH candidate set by using a reference PUSCH resource instead of a reference PUCCH resource. The reference PUSCH resource can be the PUSCH resource indicated by the DCI scheduling the PUSCH. The reference PUSCH resource can be the earliest PUSCH resource among all the PUSCH resources whose starting symbol can be indicated by the DCI scheduling the PUSCH. This is because the PDSCH processing time condition is satisfied even if the user equipment selects any PUSCH resource when the reference PUSCH resource is the PUSCH resource with the earliest starting symbol among all the PUSCH resources that can be indicated by the DCI scheduling the PUSCH. Further, the reference PUSCH resource can be the latest PUSCH resource among all the PUSCH resources whose starting symbol can be indicated by the DCI scheduling the PUSCH. This is because the maximum number of PDSCHs can be included in the PDSCH candidate set even if the user equipment selects any PUSCH resource when the reference PUSCH resource is the PUSCH resource with the latest starting symbol among all the PUSCH resources that can be indicated by the DCI scheduling the PUSCH. In other specific embodiments, even if the HARQ-ACK codebook is piggybacked on PUSCH transmissions, the user equipment may use the reference PUCCH to determine whether the PDSCH is included in the PDSCH candidate set. Specifically, the user equipment may determine whether the PDSCH is included in the PDSCH candidate set by using the resource with the advanced starting symbol among the reference PUCCH resource and the reference PUSCH resource.

[0172] Furthermore, if the time difference between the last symbol of the symbols corresponding to the PDSCH indicated by SLIV and the first symbol of the slot containing the PUCCH or PUSCH on which the HARQ-ACK is transmitted does not meet the PDSCH processing time condition, the user equipment may not include the PDSCH candidate indicated by SLIV in the PDSCH candidate set. In other specific embodiments, if the time difference between the last symbol among the symbols corresponding to the PDSCH indicated by SLIV and the first symbol of the next slot (e.g., the (n + 1)-th slot) of the slot (e.g., the n-th slot) containing the PUCCH or PUSCH on which the HARQ-ACK is transmitted does not meet the PDSCH processing time condition, the user equipment may not include the PDSCH candidate indicated by SLIV in the PDSCH candidate set.

[0173] In the embodiment of FIG. 21, the user equipment calculates N, which is the number of symbols corresponding to the time required to process the HARQ-ACK information for each PDSCH. Specifically, the user equipment calculates N = ceil(T proc,1N can be calculated using ( / symbol_duration). symbol_duration indicates the length of one symbol. Also, N can be N1. In this case, N1 can be the value defined in Table 4 above. The symbol difference from the last symbol of the first PDSCH PDSCH candidate #1 to the first symbol of the slot including the reference PUCCH or the first symbol of the reference PUSCH is greater than N. Furthermore, the symbol difference between the last symbol of the second PDSCH PDSCH candidate #2 and the first symbol of the slot including the reference PUCCH or the first symbol of the reference PUSCH is greater than N. Additionally, the symbol difference between the last symbol of the third PDSCH PDSCH candidate #3 and the first symbol of the slot including the reference PUCCH or the first symbol of the reference PUSCH is less than N. Moreover, the symbol difference between the last symbol of the fourth PDSCH PDSCH candidate #4 and the first symbol of the slot including the reference PUCCH or the first symbol of the reference PUSCH is less than N. Therefore, the user equipment may include the first PDSCH PDSCH candidate #1 and the second PDSCH PDSCH candidate #2 in the PDSCH candidate set, and the user equipment may not include the third PDSCH PDSCH candidate #3 and the fourth PDSCH PDSCH candidate #4 in the PDSCH candidate set.

[0174] In other specific embodiments, when the time difference between the last symbol between the symbols corresponding to the PDSCH indicated by SLIV and the reference symbol of the slot (e.g., the nth slot) including the PUCCH or PUSCH where HARQ-ACK is transmitted is included and does not satisfy the PDSCH processing time condition, the user equipment may not include the PDSCH candidate indicated by SLIV in the PDSCH candidate set. In this case, the reference symbol can be any one of the first, seventh, eighth, or fourteenth symbol in the slot.

[0175] In these embodiments, the above-described embodiments can be applied to operations other than the operation of determining the PDSCH processing time condition.

[0176] FIG. 22 shows that the user equipment determines a PDSCH candidate set by calculating the time required for HARQ-ACK processing of PDSCH in slot units according to an embodiment of the present invention.

[0177] The user equipment may determine PDSCH processing time conditions in slot units. Specifically, when the time difference between the last symbol in the slot including the last symbol between the symbols corresponding to the PDSCH indicated by the SLIV and the first symbol of the slot including the PUCCH or PUSCH in which the HARQ-ACK information is transmitted does not satisfy the PDSCH processing time condition, the user equipment may not include the PDSCH candidate indicated by the SLIV in the PDSCH candidate set. Specifically, when the time difference between the slot in which the PDSCH is received and the slot including the PUCCH or PUSCH in which the HARQ-ACK information is transmitted is smaller than the time required for the user equipment to process the HARQ-ACK information for the PDSCH, the user equipment may not include the corresponding PDSCH in the PDSCH candidate set. Further, when the time difference between the slot in which the PDSCH is received and the slot including the PUCCH or PUSCH in which the HARQ-ACK information is transmitted is equal to or greater than the time required for the user equipment to process the HARQ-ACK information for the PDSCH, the user equipment may include the corresponding PDSCH in the PDSCH candidate set. Assume that the length (period) of one slot is X. The unit of X may be ms. In this case, when the user equipment transmits the PUCCH or PUSCH in which the HARQ-ACK information is transmitted in the nth slot, the user equipment may not include the PDSCH received in the (n - s)th slot or the slot following the (n - s)th slot in the PDSCH candidate set. In this case, s = ceil(T proc,1 / X) may be applicable. Also, s = floor(T proc,1 / X) may be applicable. Also, s = round(T proc,1 / X) may be applicable. round(x) indicates the rounded value of x.

[0178] In the embodiment of FIG. 22, the user equipment calculates s, which is the number of slots corresponding to the time required to process HARQ-ACK information for each PDSCH. Specifically, the user equipment may calculate s using s = ceil(T proc,1 / X). X represents the length (period) of one slot. The values of s corresponding to the first PDSCH PDSCH candidate #1 to the fourth PDSCH PDSCH candidate #4 are all 2. The slot difference from the last symbol of the slot in which the first PDSCH PDSCH candidate #1 is received to the first symbol of the slot in which PUCCH or PUSCH is transmitted is 2. Furthermore, the slot difference between the last symbol of the slot in which the second PDSCH PDSCH candidate #2, the third PDSCH PDSCH candidate #3, and the fourth PDSCH PDSCH candidate #4 are received and the first symbol of the slot in which PUCCH or PUSCH is transmitted is less than 2. Therefore, the user equipment may include the first PDSCH PDSCH candidate #1 in the PDSCH candidate set, and the user equipment may not include the second PDSCH PDSCH candidate #2, the third PDSCH PDSCH candidate #3, and the fourth PDSCH PDSCH candidate #4 in the PDSCH candidate set.

[0179] In these embodiments, the above-described embodiments may be applied to operations other than the operation of determining the PDSCH processing time condition.

[0180] FIG. 23 shows that when calculating the time required for the processing for the user equipment to transmit HARQ-ACK information of the PDSCH in units of slots according to an embodiment of the present invention, the user equipment determines a PDSCH candidate set based on a reference PUCCH resource or a reference PUSCH resource.

[0181] When calculating the time required for the processing for the user equipment according to the above-described embodiment to transmit HARQ-ACK information of PDSCH in slot units, the user equipment may determine a PDSCH candidate set based on a reference PUCCH resource or a reference PUSCH resource. In this case, according to the embodiment described with reference to FIG. 21, the user equipment may determine a reference PUCCH resource or a reference PUSCH resource.

[0182] In the embodiment of FIG. 23, the user equipment calculates s, which is the number of slots corresponding to the time required for the processing for transmitting HARQ-ACK information for each PDSCH. Specifically, the user equipment may calculate s using s = ceil(T proc,1 / X). X represents the length (period) of one slot. The values of s corresponding to the first PDSCH PDSCH candidate #1 to the fourth PDSCH PDSCH candidate #4 are all 2. The slot difference from the last symbol of the slot in which the first PDSCH PDSCH candidate #1 is received to the first symbol in the slot including the reference PUCCH resource or the reference PUSCH resource is 2. Furthermore, the slot difference between the last symbol of the slot in which each of the second PDSCH PDSCH candidate #2, the third PDSCH PDSCH candidate #3, and the fourth PDSCH PDSCH candidate #4 is received and the first symbol of the slot including the reference PUCCH resource or the reference PUSCH resource is less than 2. Therefore, the user equipment may include the first PDSCH PDSCH candidate #1 in the PDSCH candidate set, and the user equipment may not include the second PDSCH PDSCH candidate #2, the third PDSCH PDSCH candidate #3, and the fourth PDSCH PDSCH candidate #4 in the PDSCH candidate set.

[0183] In these embodiments, the above-described embodiments may be applied to operations other than the operation of determining the PDSCH processing time condition.

[0184] When the user equipment is configured by the base station to aggregate slots for receiving the PDSCH, the user equipment may receive at most one PDSCH in each slot. Specifically, when the user equipment is configured by the base station to aggregate slots for receiving the PDSCH, the user equipment can expect that at most one PDSCH reception is scheduled in one slot. In this case, when the repeated reception of the PDSCH is configured to be repeated in a plurality of slots, the user equipment can determine whether to satisfy the condition of including the corresponding PDSCH in the PDSCH candidate set based on whether the PDSCH reception is available in all the slots where the PDSCH is received. Specifically, if the PDSCH reception is unavailable in at least one of all the slots indicated as the PDSCH reception, the user equipment may not include the PDSCH in the PDSCH candidate set. In this case, the PDSCH reception may be the PDSCH reception indicated by the PDSCH mapping type A. The PDSCH mapping type A indicates a PDSCH reception method in which the DMRS of the PDSCH is fixed to the third symbol or the fourth symbol of the slot. When the user equipment is configured by the base station to aggregate slots for receiving the PDSCH, the user equipment can determine the PDSCH candidate set as follows.

[0185] The user equipment may determine the size of the PDSCH candidate set according to floor((K0 max - K0 min + K1 max - K1 min ) / N rep ). In this case, K0 max represents the maximum value among the K0 values configured for the user equipment. Further, K1 max indicates the maximum value among the K1 values configured for the user equipment. Further, K0 min represents the minimum value among the K0 values configured for the user equipment. Further, K1 minrepresents the minimum value among the K1 values configured for the user equipment. In this specification, floor(x) is the largest integer less than or equal to x. In this case, N rep indicates the number of slots in which the PDSCH is repeatedly received. As described above, N rep can be configured through the RRC signal. Further, when PDSCH repetition is not used, N rep = 1.

[0186] The user equipment may determine the PDSCH included in the PDSCH candidate set using the maximum value of the K1 values. Specifically, the user equipment may use the maximum value of K1 and N rep to determine the PDSCH included in the PDSCH candidate set. Specifically, the user equipment may determine whether the PDSCH candidate indicated by the SLIV is valid for the K1 and K0 values in descending order of a plurality of K1 values. In a particular embodiment, the user equipment may generate a semi-static HARQ-ACK codebook using the following operations. For convenience of explanation, the slot in which the PUCCH is transmitted is referred to as the nth slot.

[0187] 1) The user equipment sets the length of the HARQ-ACK codebook to 0 bits.

[0188] 2) The user equipment determines whether the PDSCH candidate indicated by the SLIV is valid for the K1 max value and the K0 value. In this case, K1 max is the maximum value of the set of K1 values. K1 max is excluded from the set of K1 values. The (n - K1 max )th slot, the (n - K1 max - 1)th slot,... and the (n - K1 max - (N repFor all (n-K1)th slots, if any of the symbols indicated by the SLIV to which the PDSCH candidate is allocated in the corresponding slot overlaps with an UL symbol, the user equipment may determine that the corresponding PDSCH candidate is invalid. Specifically, if all symbols indicated by the SLIV to which the PDSCH candidate is allocated overlap with an UL symbol in the (n-K1)th slot, (n-K1-1)th slot, ..., and (n-K1-(N rep In another particular embodiment, if the SLIV does not correspond to a UL symbol in any one of the (n-K1 −1))th slots, the user equipment may determine that the PDSCH candidate indicated by the SLIV is valid. max -(N rep If at least one of the symbols indicated by the SLIV as a symbol to which the PDSCH is allocated in the (n-K1 −1))th slot overlaps with a UL symbol, the PDSCH candidate may be determined to be invalid. max -(N rep If all symbols indicated by the SLIV as symbols to which the PDSCH is allocated in the −1))th slot do not overlap with UL symbols, the PDSCH candidate may be determined to be valid.

[0189] 3) For the PDSCH candidates that the user equipment validates in step 2), the user equipment increases the length of the HARQ-ACK codebook by 1 for HARQ-ACK transmission of the PDSCH.

[0190] 4) For valid PDSCH candidates, the user equipment selects K1 from the set of K1 values. max -N rep The user equipment stops operating if the set of K1 values is an empty set, or repeats the process from 2) to 4).

[0191] The user equipment may use the minimum of the K1 value to determine the PDSCHs included in the PDSCH candidate set. Specifically, the user equipment may use the minimum of K1 and N repUsing this, the PDSCH included in the PDSCH candidate set can be determined. Specifically, the user equipment may determine whether the PDSCH candidates indicated by the SLIV are valid for the K1 and K0 values in ascending order of a plurality of K1 values. In certain embodiments, the user equipment may generate a semi-static HARQ-ACK codebook using the following operations. For the sake of convenience of explanation, the slot in which the PUCCH is transmitted is referred to as the nth slot.

[0192] 1) The user equipment sets the length of the HARQ-ACK codebook to 0 bits.

[0193] 2) The user equipment determines whether the PDSCH candidates indicated by the SLIV are valid for the K1 min value and the K0 value. In this case, K1 min is the minimum value of the set of K1 values. K1 min is excluded from the set of K1 values. For all of the (n - K1 min )th slot, the (n - K1 min -1)th slot, ... and the (n - K1 min -(N rep -1))th slot, if any one of the symbols indicated as the symbol in which the PDSCH is allocated by the SLIV in the corresponding slot corresponds to a UL symbol, the user equipment may determine that the corresponding PDSCH candidate is invalid. Specifically, if none of the symbols indicated by the SLIV as the symbols in which the PDSCH is allocated correspond to the UL symbol in any one of the (n - K1)th slot, the (n - K1 - 1)th slot, ... and the (n - K1 - (N rep -1))th slot, the user equipment may determine that the corresponding PDSCH candidate is valid. In other specific embodiments, if at least one of the symbols indicated by the SLIV as the symbols in which the PDSCH is allocated in the (n - K1 min -(N rep -1))th slot overlaps with the UL symbol, the PDSCH candidate may be determined to be invalid. (n - K1min -(N rep If all the symbols indicated by SLIV as the symbols in which PDSCH is allocated in the (N - 1)-th slot do not overlap with UL symbols, the PDSCH candidate can be determined to be valid.

[0194] 3) For the PDSCH candidates that are valid for the user equipment in step 2), the user equipment increases the length of the HARQ-ACK codebook by 1 for HARQ-ACK transmission of PDSCH.

[0195] 4) In the case of a valid PDSCH candidate, the user equipment excludes values less than K1 from the set of K1 values. The user equipment stops the operation if the set of K1 values is an empty set or when repeating the process from 2) to 4). min -N rep When the user equipment aggregates slots and receives PDSCH (i.e., when receiving repetitions over N time), the user equipment can determine the size of the HARQ-ACK codebook corresponding to the PDSCH based on the position of the first PDSCH reception. This is because when the user equipment is configured by the base station to aggregate slots to receive PDSCH, the user equipment can receive at most one PDSCH in each slot. Specifically, if the first PDSCH is received in any of the slots from the (n - (i * N))-th slot to the (n - ((i + 1) * N - 1))-th slot, the user equipment can determine that the reception of the corresponding PDSCH corresponds to the i-th bit of the HARQ-ACK codebook. In this case, i can be floor(K1 / N)+1. For example, if the first PDSCH among the PDSCHs received up to N time is received in the (n - N)-th slot to the (n - (2 * N))-th slot

[0196] When the user equipment aggregates slots and receives PDSCH (i.e., when receiving repetitions over N time), the user equipment can determine the size of the HARQ-ACK codebook corresponding to the PDSCH based on the position of the first PDSCH reception. This is because when the user equipment is configured by the base station to aggregate slots to receive PDSCH, the user equipment can receive at most one PDSCH in each slot. Specifically, if the first PDSCH is received in any of the slots from the (n - (i * N))-th slot to the (n - ((i + 1) * N - 1))-th slot, the user equipment can determine that the reception of the corresponding PDSCH corresponds to the i-th bit of the HARQ-ACK codebook. In this case, i can be floor(K1 / N)+1. For example, if the first PDSCH among the PDSCHs received up to N time is received in the (n - N)-th slot to the (n - (2 * N))-th slot rep time), the user equipment can determine the size of the HARQ-ACK codebook corresponding to the PDSCH based on the position of the first PDSCH reception. This is because when the user equipment is configured by the base station to aggregate slots to receive PDSCH, the user equipment can receive at most one PDSCH in each slot. Specifically, if the first PDSCH is received in any of the slots from the (n - (i * N))-th slot to the (n - ((i + 1) * N rep ))-th slot, the user equipment can determine that the reception of the corresponding PDSCH corresponds to the i-th bit of the HARQ-ACK codebook. In this case, i can be floor(K1 rep - 1))-th slot, the user equipment can determine that the reception of the corresponding PDSCH corresponds to the i-th bit of the HARQ-ACK codebook. In this case, i can be floor(K1 max / N rep )+1. For example, if the first PDSCH among the PDSCHs received up to N rep time is received in the (n - N)-th slot to the (n - (2 * N))-th slot rep )-th slot, the user equipment can determine that the reception of the corresponding PDSCH corresponds to the i-th bit of the HARQ-ACK codebook. In this case, i can be floor(K1 repIf received in one of the (-1))-th slots, the user equipment may determine that the reception of the corresponding PDSCH corresponds to the first bit of the HARQ-ACK codebook. N rep Of the PDSCHs received by time, the first PDSCH is (n - 2 * N rep )-th slot to (n - (3 * N rep If received in one of the (-1))-th slots, the user equipment may determine that the reception of the corresponding PDSCH corresponds to the second bit of the HARQ-ACK codebook.

[0197] FIG. 24 shows that the method of the user equipment according to an embodiment of the present invention determines a PDSCH candidate set according to whether the PDSCH is scheduled by a PDCCH received after a PDCCH that schedules a PUSCH including a HARQ-ACK codebook.

[0198] When the semi-static HARQ-ACK codebook transmission of the user equipment is configured, the user equipment may piggyback and transmit the semi-static HARQ-ACK codebook on the PUSCH. When the time resources of the PUCCH for transmitting the semi-static HARQ-ACK codebook and the time resources of the PUSCH overlap, the user equipment may piggyback and transmit the semi-static HARQ-ACK codebook on the PUSCH. In this case, the overlap of the time resources of the PUCCH and the PUSCH may mean that the slots where the PUCCH and the PUSCH are located are the same. Further, the overlap of the time resources of the PUCCH and the PUSCH may mean that the symbols where the PUCCH and the PUSCH are located are the same. Further, the overlap of the time resources of the PUCCH and the PUSCH may mean that at least one of the symbols of the PUCCH and at least one of the symbols of the PUSCH are located in the same symbol.

[0199] When the PUSCH contains the HARQ-ACK codebook, the base station does not expect that the PDSCH scheduled by the PDCCH received after the PDCCH that schedules the PUSCH containing the HARQ-ACK codebook is transmitted through the HARQ-ACK codebook included in the PUSCH. Therefore, the user equipment may not include the PDSCH scheduled in the search space located after the PDCCH for scheduling the PDSCH in the PDSCH candidate set. That is, the user equipment may not include the HARQ-ACK information of the PDSCH scheduled in the search space located after the PDCCH that schedules the PUSCH in the HARQ-ACK codebook. There are four monitoring opportunities in the embodiment of FIG. 16. When the user equipment transmits the HARQ-ACK codebook through the PUCCH, the user equipment includes the PDSCH scheduled by the PDCCH received in the four monitoring opportunities within the PDSCH candidate set. In this case, the PUSCH is scheduled by the DCI received in monitoring opportunity 1, which is the second monitoring opportunity. The HARQ-ACK codebook is transmitted through the corresponding PUSCH. Therefore, the user equipment does not include the PDSCH scheduled by the DCI received in monitoring opportunity 2, which is the third monitoring, and monitoring opportunity 3, which is the fourth monitoring opportunity, in the PDSCH candidate set.

[0200] Specifically, the user equipment may operate as follows. The user equipment may transmit a PUSCH by piggybacking UCI containing the HARQ-ACK codebook in the nth slot. In this case, DCI scheduling the PUSCH is received in the search space of the pth slot. p < n, and n - K1 - (N rep-1) When -K0 > p, the user equipment may not include the PDSCH scheduled by the DCI received in the search space after the p-th slot in the PDSCH candidate set. This is because it can be assumed that the HARQ-ACK information regarding the PDSCH scheduled by the DCI received in the search space located after the p-th slot of the PUSCH cannot be transmitted. When the user equipment piggybacks the UCI including the HARQ-ACK codebook on the PUSCH and transmits the PUSCH, the user equipment may configure the size of the HARQ-ACK codebook based on the PDCCH that schedules the PUSCH. Specifically, the user equipment may reduce the size of the HARQ-ACK codebook based on the PDCCH that schedules the corresponding PUSCH.

[0201] FIG. 25 is a diagram showing that after the user equipment according to an embodiment of the present invention receives a PDCCH indicating the transmission of the PUCCH including HARQ-ACK information, the user equipment receives a PDCCH for changing the resource where the transmission of the corresponding PUCCH is indicated.

[0202] In FIG. 25, the user equipment is shown to transmit a PUCCH including HARQ-ACK information regarding two PDSCHs respectively scheduled by two PDCCHs in a first PUCCH resource. The user equipment receives a PDCCH indicating that the user equipment transmits a PUCCH in a second PUCCH resource after a time N3 symbols prior to the start symbol of the first PUCCH resource. As described above, when the PUCCH resource is changed before the user equipment receives a PDSCH and transmits HARQ-ACK information for the corresponding PDSCH, the user equipment may not be able to transmit the PUCCH according to the changed PUCCH resource. N3 may be determined according to the minimum time required for the user equipment to process the HARQ-ACK information of the PDSCH. Specifically, when the time from acquiring the information indicated to be changed by the PUCCH resource to starting the PUCCH transmission is shorter than the time required for the user equipment to process the HARQ-ACK information of the PDSCH (that is, shorter than N3), the user equipment may not be able to transmit the PUCCH according to the changed PUCCH resource. A method for preventing this will be described.

[0203] The user equipment may not expect to receive a PDCCH that changes the PUCCH resource within a predetermined lead time from the start symbol of PUCCH transmission indicated by the base station. Further, the base station may not transmit a PDCCH that changes the PUCCH resource received by the user equipment after a predetermined lead time from the start symbol of PUCCH transmission indicated by the base station. Specifically, even if the user equipment receives a PDCCH that changes the PUCCH resource of the corresponding PUCCH after a predetermined lead time from the start symbol of PUCCH transmission indicated by the base station, the user equipment may not change the PUCCH resource according to the corresponding PDCCH. When the user equipment receives a PDCCH that changes the PUCCH resource after a predetermined lead time from the start symbol of PUCCH transmission, the user equipment may ignore the PDCCH. When the user equipment receives a PDCCH that changes the PUCCH resource of the corresponding PUCCH before a predetermined lead time from the start symbol of PUCCH transmission indicated by the base station, the user equipment may transmit the PUCCH on the PUCCH resource changed according to the corresponding PDCCH. In this case, the time leading by only the predetermined lead time may be determined according to the capabilities of the user equipment and the subcarrier spacing. Further, the time leading the predetermined lead time may be specified as the number of symbols. The number of symbols may be referred to as N3. Specifically, N3 may be determined according to the minimum time required for the user equipment to process the HARQ-ACK information of the PDSCH.

[0204] As described above, the PUCCH resource including HARQ-ACK information can be indicated to the user equipment by the PUCCH resource indicator (PRI) of the PDCCH that schedules the PDSCH corresponding to the HARQ-ACK information included in the PUCCH. Therefore, the user equipment may not expect to receive the PRI of the PDCCH that schedules the PDSCH corresponding to the HARQ-ACK information included in the PUCCH indicating a resource other than the PUCCH resource of the corresponding PUCCH after a predetermined lead time (for example, N3 symbols) from the start symbol of the PUCCH transmission indicated by the base station. For the sake of convenience of explanation, the PRI of the PDCCH that schedules the PDSCH corresponding to the HARQ-ACK information included in the PUCCH indicating a resource other than the PUCCH resource of the corresponding PUCCH is called the PUCCH resource change PRI. Specifically, even if the user equipment receives the PUCCH resource change PRI after a predetermined lead time (for example, N3 symbols) from the start symbol of the PUCCH transmission indicated by the base station, the user equipment may not change the PUCCH resource according to the corresponding PDCCH. When the user equipment receives the PUCCH resource change PRI after a predetermined lead time (for example, N3 symbols) from the start symbol of the PUCCH transmission, the user equipment may ignore the corresponding PDCCH. When the user equipment receives the PUCCH resource change PRI before a predetermined lead time (for example, N3 symbols) from the start symbol of the PUCCH transmission indicated by the base station, the user equipment may transmit the PUCCH in the PUCCH resource changed according to the corresponding PDCCH. Furthermore, the base station may not transmit the PDCCH resource change PRI to be received by the user equipment after a predetermined lead time (for example, N3 symbols) from the start symbol of the PUCCH transmission indicated by the base station.

[0205] When the type of the HARQ-ACK codebook of the user equipment is configured as a dynamic HARQ-ACK codebook (i.e., a type 2 HARQ-ACK codebook), the PUCCH resource can be changed according to the PDCCH that schedules the PDSCH corresponding to the HARQ-ACK information to be transmitted in the same slot as the slot in which the PUCCH is transmitted. Specifically, the user equipment can determine the size of the HARQ-ACK codebook based on the number of PDCCHs that schedule the PDSCH corresponding to the HARQ-ACK information to be transmitted in the same slot as the slot in which the transmission of the PUCCH received by the user equipment is indicated. For example, when the user equipment further receives a PDCCH that schedules the PDSCH corresponding to the HARQ-ACK information to be transmitted in the same slot as the slot in which the transmission of the PUCCH is indicated, the user equipment may need to increase the size of the HARQ-ACK codebook to include the HARQ-ACK of this PDSCH. The user equipment can determine the PUCCH resource set according to the size of the HARQ-ACK codebook (i.e., the number of bits of the HARQ-ACK codebook) transmitted through the PUCCH. In this case, the user equipment can select the PUCCH resource to be used for PUCCH transmission from the PUCCH resource set based on the value of the PRI field of the last PDCCH received last in time among the PDCCHs that schedule the PDSCH. Therefore, when the user equipment receives a PDCCH that schedules the PDSCH corresponding to the HARQ-ACK information to be transmitted in the same slot as the slot in which the transmission of the PUCCH received by the user equipment is indicated, the PUCCH resource may be changed.

[0206] Therefore, the user equipment may not expect that the PDCCH for changing the PUCCH resource set or PUCCH resource is to be transmitted in the same slot as the slot in which the PUCCH is transmitted after a predetermined lead time (e.g., N3 symbols) from the start symbol of the PUCCH transmission indicated by the base station, where the PDCCH for scheduling the PDSCH corresponding to the HARQ-ACK information is transmitted. For the sake of convenience of explanation, the PDCCH for changing the PUCCH resource set is referred to as the HARQ-ACK additional PDCCH as the PDCCH for scheduling the PDSCH corresponding to the HARQ-ACK information to be transmitted in the same slot as the indicated PUCCH transmission. Specifically, even if the user equipment receives the HARQ-ACK additional PDCCH after a predetermined lead time (e.g., N3 symbols) from the start symbol of the PUCCH transmission indicated by the base station, the user equipment may not change the PUCCH resource according to the corresponding PDCCH. When the user equipment receives the HARQ-ACK additional PDCCH after a predetermined lead time (e.g., N3 symbols) from the start symbol of the PUCCH transmission, the user equipment may ignore the corresponding PDCCH. When the user equipment receives the HARQ-ACK additional PDCCH before a predetermined lead time (e.g., N3 symbols) from the start symbol of the PUCCH transmission indicated by the base station, the user equipment may transmit the PUCCH in the PUCCH resource changed according to the corresponding PDCCH. Therefore, even when the user equipment receives the PDCCH for scheduling the PDSCH corresponding to the HARQ-ACK information to be transmitted in the same slot as the slot in which the PUCCH is transmitted after a predetermined lead time (e.g., N3 symbols) from the start symbol of the PUCCH transmission indicated by the base station, the PDCCH may not need to add the bits of the HARQ-ACK codebook. In this case, the user equipment may transmit the HARQ-ACK information of the PDSCH scheduled by the corresponding PDCCH through the corresponding PUCCH.Furthermore, the base station may not transmit the HARQ-ACK additional PDCCH received by the user equipment after a predetermined leading time (for example, N3 symbols) from the start symbol of the PUCCH transmission indicated by the base station.

[0207] The PUCCH resource set and PUCCH resources can be configured differently according to the UL BWP. This is because the UL transmission of the user equipment is executed within the UL BWP. Therefore, the user equipment may not expect to receive a PDCCH indicating a change in the UL BWP after a predetermined lead time (e.g., N3 symbols) from the start symbol of the PUCCH transmission indicated by the base station. Specifically, even if the user equipment receives a PDCCH indicating a change in the UL BWP after a predetermined lead time (e.g., N3 symbols) from the start symbol of the PUCCH transmission indicated by the base station, the user equipment may not change the PUCCH resources according to the corresponding PDCCH. If the user equipment receives a PDCCH indicating a change in the UL BWP after a predetermined lead time (e.g., N3 symbols) from the start symbol of the PUCCH transmission, the user equipment may ignore the corresponding PDCCH. If the user equipment receives a PDCCH indicating a change in the UL BWP before a predetermined lead time (e.g., N3 symbols) from the start symbol of the PUCCH transmission indicated by the base station, the user equipment may change the UL BWP based on the corresponding PDCCH and may transmit the PUCCH in the changed UL BWP. Specifically, if the user equipment receives a PDCCH indicating a change in the UL BWP before a predetermined lead time (e.g., N3 symbols) from the start symbol of the PUCCH transmission indicated by the base station, the user equipment may transmit the PUCCH in the changed PUCCH resources according to the changed UL BWP. Also, even if the user equipment changes the PUCCH resources after a predetermined lead time (e.g., N3 symbols) from the start symbol of the PUCCH transmission indicated by the base station, the PDCCH may not indicate a UL BWP change. Even if the user equipment changes the PUCCH resources after a predetermined lead time (e.g., N3 symbols) from the start symbol of the PUCCH transmission indicated by the base station, the user equipment may expect to receive a PDCCH that does not indicate a change in the UL BWP.In this case, the user equipment may transmit the PUCCH according to the PUCCH resource changed by the corresponding PDCCH. Further, the base station may not transmit a PDCCH indicating a change in the UL BWP received by the user equipment after a predetermined lead time (for example, N3 symbols) from the start symbol of the PUCCH transmission indicated by the base station.

[0208] When the type of the HARQ-ACK codebook of the user equipment is configured as a semi-static HARQ-ACK codebook (i.e., type 1 HARQ-ACK codebook), the PUCCH resource may be changed according to the PDCCH indicating a change in the DL BWP. Specifically, when the user equipment receives a PDCCH indicating a change in the DL BWP, the user equipment may change the DL BWP based on the corresponding PDCCH. When the user equipment changes the DL BWP, the user equipment may not transmit the HARQ-ACK information of the PDSCH scheduled before the DL BWP is changed to the base station. Specifically, when the user equipment receives a DCI for changing the DL BWP from the base station, the user equipment may exclude the PDSCH scheduled by the PDCCH received before the DL BWP change from the PDSCH candidate set. Therefore, when the user equipment changes the DL BWP by receiving a PDCCH indicating a change in the DL BWP from the base station, the size of the semi-static HARQ-ACK codebook may be reduced. As the size of the HARQ-ACK codebook decreases, the number of HARQ-ACK bits decreases, so the PUCCH resource may be changed as described above.

[0209] Therefore, the user equipment may not expect to receive a PDCCH indicating a change in the DL BWP after a predetermined lead time (e.g., N3 symbols) from the start symbol of the PUCCH transmission indicated by the base station. Specifically, even if the user equipment receives a PDCCH indicating a change in the DL BWP after a predetermined lead time (e.g., N3 symbols) from the start symbol of the PUCCH transmission indicated by the base station, the user equipment may not change the PUCCH resource according to the corresponding PDCCH. When the user equipment receives a PDCCH indicating a change in the DL BWP after a predetermined lead time (e.g., N3 symbols) from the start symbol of the PUCCH transmission, the user equipment may ignore the corresponding PDCCH. When the user equipment receives a PDCCH indicating a change in the DL BWP before a predetermined lead time (e.g., N3 symbols) from the start symbol of the PUCCH transmission indicated by the base station, the user equipment may transmit a PUCCH by excluding the HARQ-ACK information of the PDSCH scheduled before the PDCCH indicating the change in the DL BWP from the PUCCH resource changed according to the corresponding PDCCH from the semi-static HARQ-ACK codebook. Further, even if the user equipment changes the PUCCH resource after a predetermined lead time (e.g., N3 symbols) from the start symbol of the PUCCH transmission indicated by the base station, the PDCCH may not indicate a DL BWP change. Even if the user equipment changes the PUCCH resource after a predetermined lead time (e.g., N3 symbols) from the start symbol of the PUCCH transmission indicated by the base station, the user equipment may expect to receive a PDCCH that does not indicate a change in the DL BWP. In this case, the user equipment may transmit a PUCCH by reflecting the PUCCH resource changed by the corresponding PDCCH. Further, the base station may not transmit a PDCCH indicating a change in the DL BWP received by the user equipment after a predetermined lead time (e.g., N3 symbols) from the start symbol of the PUCCH transmission indicated by the base station.In the above embodiments, it has been described as the case where a semi-static HARQ-ACK codebook is configured for a user equipment. However, even when a dynamic HARQ-ACK codebook is configured for the user equipment, the above embodiments can be applied. In the above embodiments, a PDCCH indicating a change in a DL BWP can schedule a PDSCH. In this case, the corresponding PDCCH may indicate that the HARQ-ACK of the corresponding PDSCH is transmitted through a PUCCH first indicated by a base station. However, when these embodiments are applied, there may be a time interval during which the DL BWP of the user equipment cannot be changed. Therefore, these embodiments may not be suitable for application to user equipment or services that require a high-speed change in the DL BWP.

[0210] Therefore, even if the DL BWP is changed after a predetermined lead time (e.g., N3 symbols) from the start symbol of PUCCH transmission indicated by the base station, the user equipment can maintain the same size of the HARQ-ACK codebook as before the DL BWP is changed. In certain embodiments, when the DL BWP is changed after a predetermined lead time (e.g., N3 symbols) from the start symbol of PUCCH transmission, the user equipment may transmit a semi-static HARQ-ACK codebook including HARQ-ACK information of the PDSCH scheduled before the change of the DL BWP. In this case, the user equipment may configure the HARQ-ACK information of the PDSCH scheduled before the DL BWP is changed to NACK. Further, when the DL BWP is changed before a predetermined lead time (e.g., N3 symbols) from the start symbol of PUCCH transmission, the user equipment may not include the HARQ-ACK information of the PDSCH scheduled before the DL BWP change in the semi-static HARQ-ACK codebook. In other certain embodiments, the user equipment may insert padding bits into the semi-static HARQ-ACK codebook as long as the PUCCH resource set remains the same as before the DL BWP is changed. The range of the number of UCI bits corresponding to the PUCCH resource set before the DL BWP change is called from A bits to B bits. Further, the size of the UCI excluding the HARQ-ACK information of the PDSCH scheduled before the DL BWP is changed from the semi-static HARQ-ACK codebook is called C. At this time, when the size of C is smaller than the size of A, the user equipment may add A to C bits to the HARQ-ACK codebook so that the HARQ-ACK codebook satisfies the minimum value of the number of UCI bits corresponding to the PUCCH resource set. When the size of C is greater than or equal to the size of A, the user equipment may transmit the semi-static HARQ-ACK codebook through the PUCCH by excluding the HARQ-ACK information of the PDSCH scheduled before the DL BWP is changed from the semi-static HARQ-ACK codebook.Even if the DL BWP is changed through these embodiments, the user equipment may transmit PUCCH on the same PUCCH resource of the same PUCCH resource set.

[0211] In the above embodiments, the physical data channel may include PDSCH or PUSCH. Further, the physical control channel may include PDCCH or PUCCH. Further, in the embodiments described using PUSCH, PDCCH, PUCCH, and PDCCH, other types of data channels and control channels may be applicable.

[0212] The methods and systems of the present disclosure are described in connection with specific embodiments, and components, some or all of the operations of the present disclosure, may be implemented using a computer system having a general-purpose hardware architecture.

[0213] The foregoing description of the present disclosure has been presented for purposes of illustration and description. It will be apparent to those skilled in the art to which the present disclosure pertains that the present disclosure can be easily modified into other detailed forms without changing the technical principles or essential features of the present disclosure. Accordingly, these embodiments described above are proposed for purposes of illustration only and are not intended to limit the present disclosure. For example, each component described as being of a single type can be implemented in a distributed manner. Similarly, components described as being distributed can be implemented in combination.

[0214] The scope of the present disclosure is presented not by the foregoing description but by the appended claims. It should be understood that all changes or modifications derived from the definitions and scope of the claims and their equivalents are within the scope of the present disclosure.

Description of Reference Numerals

[0215] 100 UE 110 Processor 120 Communication Module 121 Cellular Communication Interface Card 122 Cellular communication interface card 123 Communication interface card for unlicensed band 130 Memory 140 User interface 150 Display unit 200 Base station 210 Processor 220 Communication module 221 Cellular communication interface card 222 Cellular communication interface card 223 Communication interface card for unlicensed band 230 Memory

Claims

1. A user equipment configured to operate in a wireless communication system based on the 3rd Generation Partnership Project New Radio (3GPP NR), comprising: a communication module; a processor configured to control the communication module, the processor being configured to: receive a Physical Downlink Shared Channel (PDSCH) on one of a plurality of Downlink (DL) Bandwidth Parts (BWP) of a cell; determine a size of a semi-static Hybrid Automatic Repeat reQuest - ACKnowledgement (HARQ-ACK) codebook based on the reception of the PDSCH; determine a Physical Uplink Control Channel (PUCCH) resource for the semi-static HARQ-ACK codebook, the PUCCH resource belonging to a PUCCH resource set associated with the size of the semi-static HARQ-ACK codebook; and perform the above; The first physical downlink control channel (PDCCH) is N resources before the PUCCH resource. 3 When the first PDCCH is received within a symbol, the user equipment does not expect the first PDCCH to indicate a DL BWP change, and the size of the semi-static HARQ-ACK codebook is not changed, and N 3 is a positive number, The second PDCCH is received earlier than the symbol before the PUCCH resource, and when the second PDCCH indicates a DL BWP change, the size of the semi-static HARQ-ACK codebook is determined by excluding HARQ-ACK information related to the PDSCH scheduled in one or more slots before the DL BWP change indicated by the second PDCCH in the slot associated with the semi-static HARQ-ACK codebook. 3 When the second PDCCH is received earlier than the symbol before the PUCCH resource and the second PDCCH indicates a DL BWP change, the size of the semi-static HARQ-ACK codebook is determined by excluding HARQ-ACK information related to the PDSCH scheduled in one or more slots before the DL BWP change indicated by the second PDCCH in the slot associated with the semi-static HARQ-ACK codebook. User equipment.

2. The foregoing N 3 The user equipment according to claim 1, wherein the symbol is a symbol before the start symbol of the PUCCH resource.

3. Said N 3 The symbol is determined based on the capabilities of the user equipment and the subcarrier spacing, and the user equipment according to claim 1 or 2.

4. The user equipment according to any one of claims 1 to 3, wherein the semi-static HARQ-ACK codebook is transmitted by using the PUCCH resource.

5. The user equipment according to any one of claims 1 to 4, wherein the PUCCH resource set is selected from a plurality of PUCCH resource sets based on the size of the semi-static HARQ-ACK codebook.

6. A method for use by a user equipment of a wireless communication system, comprising: receiving a Physical Downlink Shared Channel (PDSCH) on one of a plurality of Downlink (DL) Bandwidth Parts (BWP) of a cell; determining a size of a semi-static Hybrid Automatic Repeat reQuest - ACKnowledgement (HARQ-ACK) codebook based on the reception of the PDSCH; determining a Physical Uplink Control Channel (PUCCH) resource for the semi-static HARQ-ACK codebook, the PUCCH resource belonging to a PUCCH resource set associated with the size of the semi-static HARQ-ACK codebook; and including the above steps; When the first physical downlink control channel (PDCCH) is received within N symbols before the PUCCH resource, the user equipment does not expect the first PDCCH to indicate a DL BWP change, and the size of the semi-static HARQ-ACK codebook does not change, where N 3 is a positive number, 3 and The second PDCCH is received earlier than the symbol that is earlier than the PUCCH resource, and when the second PDCCH indicates a DL BWP change, the size of the semi-static HARQ-ACK codebook is within the slot associated with the semi-static HARQ-ACK codebook, excluding HARQ-ACK information related to the PDSCH scheduled in one or more slots before the DL BWP change indicated by the second PDCCH. 3 determined by excluding HARQ-ACK information related to the PDSCH scheduled in one or more slots before the DL BWP change indicated by the second PDCCH. Method.

7. The foregoing N 3 The method according to claim 6, wherein the symbol is a symbol before the start symbol of the PUCCH resource.

8. The foregoing N 3 symbol is determined based on the capabilities of the user equipment and the subcarrier spacing, the method according to claim 6 or 7.

9. The method according to any one of claims 6 to 8, wherein the semi-static HARQ-ACK codebook is transmitted by using the PUCCH resource.

10. The method according to any one of claims 6 to 9, wherein the PUCCH resource set is selected from a plurality of PUCCH resource sets based on the size of the semi-static HARQ-ACK codebook.

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