Method and apparatus for transmitting and receiving signals in a wireless communication system

Abstract

According to at least one of various embodiments of the present invention, a terminal receives a DCI via a PDCCH, receives at least one TB via a PDSCH in at least one of a plurality of cells configured for the terminal based on the DCI, and transmits HARQ-ACK information for the at least one TB, wherein the DCI supports multi-cell scheduling based on the plurality of cells, and a number of ACK / NACK bits included in the HARQ-ACK information is determined based on at least one of a maximum number of cells that can be co-scheduled by the DCI or a maximum number of TBs that can be received via cells co-scheduled by the DCI.

Description

[Technical field]

[0001] The present invention relates to wireless communication systems, and more particularly to a method and apparatus for transmitting or receiving uplink / downlink radio signals in a wireless communication system. [Background technology]

[0002] Wireless communication systems have been widely deployed to provide various communication services such as voice and data. In general, wireless communication systems are multiple access systems that can support communication with multiple users by sharing available system resources (bandwidth, transmission power, etc.). Examples of multiple access systems include code division multiple access (CDMA) systems, frequency division multiple access (FDMA) systems, time division multiple access (TDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, etc. Summary of the Invention [Problem to be solved by the invention]

[0003] The technical problem to be solved is to provide a method and an apparatus for efficiently performing a process of transmitting and receiving a radio signal.

[0004] The technical problem to be achieved is not limited thereto, and other technical problems not mentioned will be clearly understood by those having ordinary skill in the art to which the present invention pertains from the following description. [Means for solving the problem]

[0005] According to one aspect of the present invention, a method for a terminal receiving a signal in a wireless communication system includes receiving, downlink control information (DCI) through a physical downlink control channel (PDCCH), receiving, based on the DCI, at least one transport block (TB) through a physical downlink shared channel (PDSCH) in at least one of a plurality of cells configured in the UE, and transmitting hybrid automatic repeat request-acknowledgement (HARQ-ACK) information for the at least one TB. The DCI may support multi-cell scheduling based on the plurality of serving cells.The number of acknowledgement / negative-acknowledgement (ACK / NACK) bits included in the HARQ-ACK information may be determined based on at least one of a maximum number of cells that can be co-scheduled by the DCI, or a maximum number of TBs that can be received through cells co-scheduled by the DCI.

[0006] Based on the fact that in at least one of the cells that can be co-scheduled by the DCI, the maximum number of TBs per PDSCH is 2 and spatial bundling is not configured, the number of ACK / NACK bits included in the HARQ-ACK information is determined based on the maximum number of TBs that can be received via the cells that can be co-scheduled by the DCI.

[0007] Based on the maximum number of TBs per PDSCH being 1 or spatial bundling being configured in each of the cells that can be scheduled together by the DCI, the number of ACK / NACK bits included in the HARQ-ACK information is determined based on the maximum number of cells that can be scheduled together by the DCI.

[0008] The maximum number of cells that can be co-scheduled by the DCI is related to the cell combination that includes the most cells among the cell combinations that can be co-scheduled by the DCI.

[0009] Within the HARQ-ACK information, the ACK / NACK bits are aligned based on the serving cell index of the co-scheduled cells.

[0010] The DCI includes information about a downlink assignment index (DAI), which is determined based on a cell having a minimum serving cell index among cells co-scheduled by the DCI.

[0011] The HARQ-ACK information for the multi-cell scheduling is included in a second sub-codebook, and the HARQ-ACK information for the single-cell scheduling is included in a first sub-codebook.

[0012] One HARQ-ACK codebook is constructed based on the concatenation of the first sub-codebook and the second sub-codebook.

[0013] The second sub-codebook is associated with a PDSCH scheduled by a multi-cell scheduling DCI in which two or more cells are actually scheduled, and the first sub-codebook is associated with a PDSCH scheduled by a multi-cell scheduling DCI and a single-cell scheduling DCI in which one cell is actually scheduled.

[0014] According to another aspect of the present invention, there is provided a processor-readable recording medium having a program recorded thereon for carrying out the above-described method.

[0015] According to another aspect, there is provided a terminal for performing the above-mentioned method.

[0016] According to yet another aspect, there is provided an apparatus for controlling a terminal to perform the method described above.

[0017] According to another aspect, a method for transmitting a signal by a base station in a wireless communication system includes transmitting downlink control information (DCI) to a terminal via a physical downlink control channel (PDCCH), transmitting at least one transport block (TB) via a physical downlink shared channel (PDSCH) in at least one of a plurality of cells configured for the terminal based on the DCI, and receiving hybrid automatic repeat request-acknowledgement (HARQ-ACK) information for the at least one TB. The DCI supports multi-cell scheduling based on the plurality of cells. A number of acknowledgement / negative-acknowledgement (ACK / NACK) bits included in the HARQ-ACK information is determined based on at least one of a maximum number of cells that can be co-scheduled by the DCI or a maximum number of TBs that can be transmitted via cells co-scheduled by the DCI.

[0018] According to yet another aspect, there is provided a base station for performing the above-described method. Effect of the Invention

[0019] According to at least one of various embodiments, it is possible to efficiently transmit and receive radio signals in a wireless communication system.

[0020] The effects obtained by the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those having ordinary skill in the art to which the present invention pertains from the following description. [Brief description of the drawings]

[0021] [Figure 1]1 is a diagram illustrating physical channels used in a 3GPP (registered trademark) system, which is an example of a wireless communication system, and a general signal transmission method using these channels. [Diagram 2] FIG. 1 illustrates a structure of a radio frame. [Diagram 3] FIG. 2 illustrates a resource grid of slots. [Figure 4] A diagram showing an example of mapping physical channels within a slot. [Diagram 5] A diagram illustrating a PDCCH / PDSCH reception and ACK / NACK transmission process. [Figure 6] FIG. 1 illustrates a PUSCH (Physical Uplink Shared Channel) transmission process. [Figure 7] FIG. 2 illustrates an example of carrier merging. [Figure 8] FIG. 1 illustrates a wireless communication system that supports unlicensed bands. [Figure 9] FIG. 1 illustrates a method for occupying resources in an unlicensed spectrum. [Figure 10] FIG. 13 is a diagram illustrating an example of determining the number of A / N bits. [Figure 11] A diagram showing an example of cells co-scheduled by DCI. [Figure 12] FIG. 13 is a diagram showing an example of A / N bit alignment. [Figure 13] 1 is a diagram illustrating a method for a terminal to receive a signal according to one embodiment. [Figure 14] 1 is a diagram illustrating a method in which a base station transmits a signal according to one embodiment. [Figure 15] 1 is a diagram illustrating a communication system 1 and wireless devices applicable to the present invention. [Figure 16] 1 is a diagram illustrating a communication system 1 and wireless devices applicable to the present invention. [Figure 17] 1 is a diagram illustrating a communication system 1 and wireless devices applicable to the present invention. [Figure 18] 1 is a diagram illustrating a communication system 1 and wireless devices applicable to the present invention. [Figure 19] FIG. 2 is a diagram illustrating a DRX (Discontinuous Reception) operation applicable to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The following technologies can be used for 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 frequency division multiple access (SC-FDMA), etc. CDMA can be implemented by radio technologies such as Universal Terrestrial Radio Access (UTRA) and CDMA2000. TDMA can be implemented by radio 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 radio technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, Evolved UTRA (E-UTRA), etc. UTRA is part of the Universal Mobile Telecommunications System (UMTS). 3GPP (3rd Generation Partnership Project) LTE (long term evolution) is part of E-UMTS (Evolved UMTS) that uses E-UTRA, and LTE-A is an evolution of 3GPP LTE. 3GPP NR (New Radio or New Radio Access Technology) is an evolution of 3GPP LTE / LTE-A.

[0023] As more communication devices require larger communication capacity, the need for improved mobile broadband (eMBB) communication compared to existing radio access technology (RAT) is emerging. In addition, large-scale MTC (massive machine type communications), which connects multiple devices and objects to provide various services anytime and anywhere, is one of the important issues to be considered in next-generation communications. In addition, URLLC (Ultra-Reliable and Low Latency Communication) considering reliability and latency-sensitive services / UEs is being discussed. Thus, the introduction of next-generation RATs considering eMBB (enhanced mobile broadband communication), large-scale MTC, URLLC (Ultra-Reliable and Low Latency Communication), etc. is being discussed, and for convenience, the relevant technology is referred to as NR (New radio or New RAT) in this specification.

[0024] For clarity of explanation, 3GPP NR will be mainly described, but the technical idea of ​​the present invention is not limited thereto.

[0025] In this specification, the term "setting" may be replaced with the term "configure / configuration", and the two terms may be used interchangeably. Conditional expressions (e.g., "if", "in a case", or "when") may be replaced with expressions such as "based on that" or "in a state / status". The operation or SW / HW configuration of a terminal / base station due to the satisfaction of the relevant condition may be inferred / understood. In addition, in signal transmission / reception between wireless communication devices (e.g., base station, terminal), if the process of the receiving (or transmitting) side can be inferred / understood from the process of the transmitting (or receiving) side, the explanation may be omitted. For example, the signal determination / generation / encoding / transmission of the transmitting side can be understood as the signal monitoring reception / decoding / determination of the receiving side. In addition, an expression that a terminal performs (or does not perform) a specific operation may also be interpreted as the base station operating while expecting / assuming (or expecting / assuming not to perform) the specific operation of the terminal. The expression that the base station performs (or does not perform) a specific operation can also be interpreted as the terminal expecting / assuming (or expecting / assuming not to perform) the execution of a specific operation of the base station. In addition, in the following description, the divisions and indexes of each section, embodiment, example, option, method, solution, etc. are for convenience of explanation and should not be interpreted as meaning that each necessarily constitutes an independent invention or that each necessarily must be implemented individually. In addition, in describing each section, embodiment, example, option, method, solution, etc., unless there is an explicitly conflicting / opposing technology, it is inferred / interpreted that at least some of them may be combined and implemented together, or at least some may be omitted and implemented.

[0026] In a wireless communication system, a terminal receives information from a base station through a downlink (DL), and transmits information from the base station through an uplink (UL). Information transmitted and received between the base station and the terminal includes data and various control information, and various physical channels exist depending on the type / purpose of the information transmitted and received.

[0027] FIG. 1 is a diagram illustrating physical channels used in a 3GPP NR system and a typical signal transmission method using these channels.

[0028] A terminal that has been turned on in a power-off state or that has newly entered a cell performs an initial cell search operation such as establishing synchronization with a base station in step S101. To this end, the terminal receives a synchronization signal block (SSB) from the base station. The SSB includes a primary synchronization signal (PSS), a secondary synchronization signal (SSS) and a physical broadcast channel (PBCH). The terminal establishes synchronization with the base station based on the PSS / SSS and obtains information such as a cell identity (cell ID). The terminal also obtains broadcast information within the cell based on the PBCH. In addition, the terminal can receive a downlink reference signal (DL RS) during the initial cell search stage to check the state of the downlink channel.

[0029] After completing the initial cell search, in step S102, the terminal receives a Physical Downlink Control Channel (PDCCH) and a Physical Downlink Shared Channel (PDSCH) based on information of the Physical Downlink Control Channel to obtain more specific system information.

[0030] Thereafter, the terminal performs a random access procedure such as steps S103 to S106 to complete connection to the base station. To this end, the terminal transmits a preamble through a physical random access channel (PRACH) (S103) and receives a response message to the preamble through a physical downlink control channel and a corresponding physical downlink shared channel (S104). In the case of contention based random access, the terminal performs a contention resolution procedure such as transmitting a further physical random access channel (S105) and receiving a physical downlink control channel and a corresponding physical downlink shared channel (S106).

[0031] After performing this procedure, the terminal then receives a physical downlink control channel / physical downlink shared channel (S107) and transmits a physical uplink shared channel (Physical Uplink Shared Channel, PUSCH) / physical uplink control channel (Physical Uplink Control Channel, PUCCH) as a general uplink / downlink signal transmission procedure (S108). The control information transmitted by the terminal to the base station is collectively referred to as uplink control information (UCI). UCI includes HARQ ACK / NACK (Hybrid Automatic Repeat and reQuest Acknowledgement / Negative-ACK), SR (Scheduling Request), CSI (Channel State Information), etc. CSI includes CQI (Channel Quality Indicator), PMI (Precoding Matrix Indicator), RI (Rank Indication), etc. UCI is generally transmitted via PUCCH, but when control information and traffic data need to be transmitted simultaneously, it is transmitted via PUSCH. In addition, UCI can be transmitted aperiodically via PUSCH upon request / instruction from the network.

[0032] Meanwhile, the voluntary access procedure (RACH procedure) is not limited to the one for initial network access (e.g., S103 to S106) and can be used for various purposes. For example, the voluntary access procedure can be used for any of the RRC connection re-establishment procedure, handover, UE-triggered UL data transmission, transition from RRC_INACTIVE, SCell time alignment, system information request and beam failure recovery, and UL resource request, but is not limited thereto. The UE can obtain UL synchronization and / or UL transmission resources through the voluntary access procedure.

[0033] FIG. 2 illustrates the structure of a radio frame. In NR, uplink and downlink transmissions are composed of frames. A radio frame has a length of 10 ms and is defined as two 5 ms half-frames (HF). A half-frame is defined as five 1 ms subframes (SF). A subframe is divided into one or more slots, and the number of slots in a subframe depends on the subcarrier spacing (SCS). Each slot contains 12 or 14 OFDM(A) symbols depending on the cyclic prefix (CP). If a general CP is used, each slot contains 14 symbols. If an extended CP is used, each slot contains 12 symbols.

[0034] Table 1 illustrates that the number of symbols per slot, the number of slots per frame, and the number of slots per subframe change depending on the SCS when a general CP is used.

[0035] [Table 1]

[0036] *N slot symb :Number of symbols in the slot

[0037] *N frame,u slot : Number of slots in the frame

[0038] *N subframe,u slot : Number of slots in a subframe

[0039] Table 2 illustrates that the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary with the SCS when an extended CP is used.

[0040] [Table 2]

[0041] The frame structure is exemplary only, and the number of subframes, slots, and symbols within a frame can vary.

[0042] In the NR system, OFDM numerology (e.g., SCS) can be set to be different between multiple cells merged into one terminal. Accordingly, the (absolute time) duration of time resources (e.g., SF, slot, or TTI) (for convenience, commonly referred to as TU (Time Unit)) consisting of the same number of symbols can be set to be different between the merged cells. Here, the symbols include OFDM symbols (or CP-OFDM symbols) and SC-FDMA symbols (or Discrete Fourier Transform-spread-OFDM, DFT-s-OFDM symbols).

[0043] FIG. 3 is a diagram illustrating a resource grid of a slot. A slot includes a number of symbols in the time domain. For example, in the case of a general CP, one slot includes 14 symbols, while in the case of an extended CP, one slot includes 12 symbols. A carrier includes a number of subcarriers in the frequency domain. A resource block (RB) is defined as a number of (e.g., 12) consecutive subcarriers in the frequency domain. A BWP is defined as a number of consecutive physical RBs (PRBs) in the frequency domain and can correspond to one numerology (e.g., SCS, CP length, etc.). A carrier includes up to N (e.g., 5) BWPs. Data communication is performed in an activated BWP, and only one BWP is activated for one terminal. In the resource grid, each element is called a resource element (RE), and one complex symbol can be mapped to it.

[0044] Figure 4 is a diagram showing an example of mapping physical channels within a slot. PDCCH is transmitted in the DL control region, and PDSCH is transmitted in the DL data region. PUCCH is transmitted in the UL control region, and PUSCH is transmitted in the UL data region. GP provides a time gap when the base station and the terminal switch from a transmission mode to a reception mode or from a reception mode to a transmission mode. Some symbols at the time of switching from DL to UL within a subframe can be set as GP.

[0045] Each physical channel is described in more detail below.

[0046] The PDCCH carries Downlink Control Information (DCI). For example, the PCCCH (i.e., DCI) carries the transmission format and resource allocation of the DL-SCH (downlink shared channel), resource allocation information for the UL-SCH (uplink shared channel), paging information for the PCH (paging channel), system information on the DL-SCH, resource allocation information for higher layer control messages such as voluntary access responses transmitted on the PDSCH, transmission power control commands, activation / deactivation of configured scheduling (CS), etc. The DCI includes a cyclic redundancy check (CRC), and the CRC is masked / scrambled to various identifiers (e.g., Radio Network Temporary Identifier, RNTI) depending on the owner or use of the PDCCH. For example, if the PDCCH is for a specific terminal, the CRC is masked to a terminal identifier (e.g., cell-RNTI, C-RNTI). If the PDCCH is for paging, the CRC is masked to a P-RNTI (Paging-RNTI). If the PDCCH is for system information (e.g., System Information Block, SIB), the CRC is masked with a System Information RNTI (SI-RNTI). If the PDCCH is for an unsolicited access response, the CRC is masked with a Random Access-RNTI (RA-RNTI).

[0047] The PDCCH is composed of 1, 2, 4, 8, or 16 CCEs (Control Channel Elements) depending on the AL (Aggregation Level). A CCE is a logical allocation unit used to provide a PDCCH with a predetermined code rate according to the radio channel condition. A CCE is composed of 6 REGs (Resource Element Groups). A REG is defined by one OFDM symbol and one (P)RB. The PDCCH is transmitted by a CORESET (Control Resource Set). A CORESET is defined by a set of REGs having a given neurology (e.g., SCS, CP length, etc.). Multiple CORESETs for one UE can be overlapped in the time / frequency domain. A CORESET is set by system information (e.g., Master Information Block, MIB) or UE-specific higher layer (e.g., Radio Resource Control, RRC, layer) signaling. Specifically, the number of RBs and the number of OFDM symbols (maximum 3) constituting a CORESET are set by higher layer signaling.

[0048] For PDCCH reception / detection, the terminal monitors PDCCH candidates. PDCCH candidates indicate the CCEs that the terminal monitors for PDCCH detection. Each PDCCH candidate is defined by 1, 2, 4, 8, or 16 CCEs depending on the AL. Monitoring includes (blind) decoding the PDCCH candidates. The set of PDCCH candidates that the terminal monitors is defined as a PDCCH search space (SS). The search space includes a common search space (CSS) or a UE-specific search space (USS). The terminal can obtain DCI by monitoring PDCCH candidates in one or more search spaces configured by MIB or higher layer signaling. Each CORESET is associated with one or more search spaces, and each search space is associated with one COREST. The search space is defined based on the following parameters:

[0049] - controlResourceSetId: Indicates the CORESET associated with the search space.

[0050] - monitoringSlotPeriodicityAndOffset: indicates the PDCCH monitoring period (in slots) and the PDCCH monitoring period offset (in slots).

[0051] - monitoringSymbolsWithinSlot: indicates the PDCCH monitoring symbols within the slot (e.g. indicates the first symbol of the SORESET).

[0052] - nrofCandidates: indicates the number of PDCCH candidates (one of 0, 1, 2, 3, 4, 5, 6, 8) for AL={1, 2, 4, 8, 16}.

[0053] *An opportunity (e.g., time / frequency resource) for monitoring a PDCCH candidate is defined as a PDCCH (monitoring) opportunity. One or more PDCCH (monitoring) opportunities are configured within a slot.

[0054] Table 3 illustrates the characteristics of each search space type.

[0055] [Table 3]

[0056] Table 4 illustrates an example of a DCI format transmitted via the PDCCH.

[0057] [Table 4]

[0058] DCI format 0_0 is used to schedule a TB-based (or TB-level) PUSCH, and DCI format 0_1 ​​is used to schedule a TB-based (or TB-level) PUSCH or a Code Block Group (CBG)-based (or CBG-level) PUSCH. DCI format 1_0 is used to schedule a TB-based (or TB-level) PDSCH, and DCI format 1_1 is used to schedule a TB-based (or TB-level) PDSCH or a CBG-based (or CBG-level) PDSCH. DCI format 0_0 / 0_1 is called UL grant DCI or UL scheduling information, and DCI format 1_0 / 1_1 is called DL grant DCI or DL ​​scheduling information. DCI format 2_0 is used to deliver dynamic slot format information (e.g., dynamic SFI) to a terminal, and DCI format 2_1 is used to deliver downlink pre-Emption information to a terminal. DCI format 2_0 and / or DCI format 2_1 are transmitted to terminals in a corresponding group via a group common PDCCH, which is a PDCCH transmitted to terminals defined in one group.

[0059] DCI format 0_0 and DCI format 1_0 are called fallback DCI formats, and DCI format 0_1 ​​and DCI format 1_1 are called non-fallback DCI formats. The fallback DCI format maintains the same DCI size / field configuration regardless of the terminal settings. On the other hand, the non-fallback DCI format has a different DCI size / field configuration depending on the terminal settings.

[0060] PDSCH carries downlink data (e.g. DL-SCH transport block, DL-SCH TB) and uses modulation methods such as QPSK (Quadrature Phase Shift Keying), 16QAM (Quadrature Amplitude Modulation), 64QAM, and 256QAM. The TB is encoded to generate a codeword. PDSCH carries up to two codewords. Scrambling and modulation mapping are performed for each codeword, and the modulation symbols generated from each codeword are mapped to one or more layers. Each layer is mapped to resources together with DMRS (Demodulation Reference Signal) to generate an OFDM symbol signal, which is then transmitted by the corresponding antenna port.

[0061] The PUCCH carries Uplink Control Information (UCI), which includes:

[0062] - SR (Scheduling Request): Information used to request UL-SCH resources.

[0063] - HARQ-ACK: A response to a downlink data packet (e.g., a codeword) on the PDSCH. It indicates whether the downlink data packet is successfully received or not. One HARQ-ACK bit is sent as a response to a single codeword, and two HARQ-ACK bits are sent as a response to two codewords. HARQ-ACK responses include positive ACK (simply, ACK), negative ACK (hereinafter, NACK), DTX (Discontinuous Transmission), or NACK / DTX. Here, the term HARQ-ACK is used interchangeably with HARQ ACK / NACK and ACK / NACK.

[0064] CSI (Channel State Information): Feedback information for a downlink channel. Multiple Input Multiple Output (MIMO)-related feedback information includes a Rank Indicator (RI) and a Precoding Matrix Indicator (PMI).

[0065] Table 5 shows an example of a PUCCH format. According to the PUCCH transmission length, it can be divided into Short PUCCH (formats 0 and 2) and Long PUCCH (formats 1, 3 and 4).

[0066] [Table 5]

[0067] PUCCH format 0 carries UCI with a maximum size of 2 bits and is mapped and transmitted based on a sequence. Specifically, the terminal transmits one of a plurality of sequences via a PUCCH with PUCCH format 0 to transmit a specific UCI to the base station. The terminal transmits a PUCCH with PUCCH format 0 within a PUCCH resource for a corresponding SR setting only when transmitting a positive SR.

[0068] PUCCH format 1 carries UCI with a maximum size of 2 bits, and the modulation symbols are spread by an orthogonal cover code (OCC) in the time domain (set differently depending on whether frequency hopping is used or not). DMRS is transmitted in symbols where no modulation symbols are transmitted (i.e., transmitted using TDM (Time Division Multiplexing)).

[0069] PUCCH format 2 carries UCI with a bit size larger than 2 bits, and modulation symbols are transmitted after frequency division multiplexing (FDM) with DMRS. DM-RS is located at symbol indexes #1, #4, #7, and #10 in a 1 / 3 density resource block. A Pseudo Noise (PN) sequence is used for the DM_RS sequence. Frequency hopping can be activated for the 2-symbol PUCCH format 2.

[0070] In PUCCH format 3, terminal multiplexing is not performed within the same physical resource block, and UCI with a bit size larger than 2 bits is carried. That is, the PUCCH resource of PUCCH format 3 does not include an orthogonal cover code. The modulation symbol is transmitted after being subjected to TDM (Time Division Multiplexing) with DMRS.

[0071] PUCCH format 4 supports multiplexing of up to four terminals in the same physical resource block and carries UCI with a bit size larger than 2 bits. That is, the PUCCH resource of PUCCH format 3 includes an orthogonal cover code. Modulation symbols are transmitted after being time division multiplexed (TDM) with DMRS.

[0072] The PUSCH carries uplink data (e.g., UL-SCH transport block, UL-SCH TB) and / or uplink control information (UCI) and is transmitted based on a cyclic prefix-orthogonal frequency division multiplexing (CP-OFDM) waveform or a discrete Fourier transform-spread-orthogonal frequency division multiplexing (DFT-s-OFDM) waveform. When the PUSCH is transmitted based on the DFT-s-OFDM waveform, the terminal applies transform precoding to transmit the PUSCH. As an example, when transform precoding is not possible (e.g., transform precoding is disabled), the terminal transmits the PUSCH based on the CP-OFDM waveform, and when transform precoding is possible (e.g., transform precoding is enabled), the terminal transmits the PUSCH based on the CP-OFDM waveform or the DFT-s-OFDM waveform. PUSCH transmissions may be dynamically scheduled by UL grants in the DCI or semi-statically scheduled (configured grant) based on higher layer (e.g., RRC) signaling (and / or Layer 1 (L1) signaling (e.g., PDCCH)). PUSCH transmissions may be codebook-based or non-codebook-based.

[0073] Figure 5 illustrates a process of receiving PDCCH / PDSCH and transmitting ACK / NACK. Referring to Figure 5, a terminal detects a PDCCH in slot #n. Here, the PDCCH includes downlink scheduling information (e.g., DCI format 1_0, 1_1), and the PDCCH indicates DL allocation-to-PDSCH offset (K0) and PDSCH-HARQ-ACK report offset (K1). For example, DCI formats 1_0, 1_1 include the following information:

[0074] - Frequency domain resource assignment: Indicates the RB set assigned to the PDSCH.

[0075] - Time domain resource assignment: Indicates K0 (e.g. slot offset), the starting position of the PDSCH within slot #n+K0 (e.g. OFDM symbol index) and the length of the PDSCH (e.g. number of OFDM symbols).

[0076] - PDSCH-to-HARQ_feedback timing indicator: Indicates K1.

[0077] - HARQ process number (4 bits): Indicates the HARQ process ID (Identity) for data (e.g., PDSCH, TB).

[0078] Thereafter, the terminal receives the PDSCH from slot #(n+K0) according to the scheduling information of slot #n, and then transmits UCI via PUCCH in slot #(n1+K1) when the reception of the PDSCH is completed in slot #n1 (where n+K0≦n1). Here, the UCI includes a HARQ-ACK response to the PDSCH. For convenience, in FIG. 5, it is assumed that the SCS for the PDSCH and the SCS for the PUCCH are the same and that slot #n1=slot #n+K0, but the present invention is not limited thereto. If the SCSs are different, K1 is indicated / interpreted based on the SCS of the PUCCH.

[0079] If the PDSCH is configured to transmit up to 1 TB, the HARQ-ACK response consists of 1 bit. If the PDSCH is configured to transmit up to 2 TB, the HARQ-ACK response consists of 2 bits if spatial bundling is not configured and 1 bit if spatial bundling is configured. If the transmission time of the HARQ-ACK for multiple PDSCHs is specified as slot #(n+K1), the UCI transmitted in slot #(n+K1) includes the HARQ-ACK response for multiple PDSCHs.

[0080] Whether or not the UE performs spatial bundling for the HARQ-ACK response is configured for each cell group (e.g., RRC / higher layer signaling). As an example, spatial bundling is configured separately for each of the HARQ-ACK response transmitted via the PUCCH and / or the HARQ-ACK response transmitted via the PUSCH.

[0081] Spatial bundling is supported when the maximum number of TBs (or codewords) that can be received at one time (or scheduled by one DCI) in a corresponding serving cell is two (or more than two) (for example, when the upper layer parameter maxNrofCodeWordsScheduledByDCI corresponds to 2-TB). Meanwhile, more than four layers are used for 2-TB transmission, and up to four layers are used for 1-TB transmission. As a result, when spatial bundling is configured in a corresponding cell group, spatial bundling is performed on serving cells in the corresponding cell group that can schedule more than four layers. A terminal that wishes to transmit a HARQ-ACK response through spatial bundling on a corresponding serving cell can generate a HARQ-ACK response by performing a bit-wise logical AND operation on A / N bits for multiple TBs.

[0082] For example, assuming that a terminal receives DCI scheduling 2-TB and receives 2-TB via PDSCH based on the DCI, a terminal performing spatial bundling can generate a single A / N bit by logically ANDing the first A / N bit for the first TB and the second A / N bit for the second TB. As a result, if both the first TB and the second TB are ACK, the terminal reports an ACK bit value to the base station, and if both TBs are NACK, the terminal reports a NACK bit value to the base station.

[0083] For example, if only 1-TB is actually scheduled on a serving cell that is configured to receive 2-TB, the terminal can generate a single A / N bit by logically ANDing the A / N bit for the 1-TB with a bit value of 1. As a result, the terminal reports the A / N bit for the 1-TB to the base station as is.

[0084] A base station / terminal has multiple parallel DL HARQ processes for DL ​​transmission. Multiple parallel HARQ processes allow DL transmission to be performed continuously while waiting for HARQ feedback for successful or unsuccessful reception of previous DL transmission. Each HARQ process is associated with a HARQ buffer in the Medium Access Control (MAC) layer. Each DL HARQ process manages state variables related to the number of transmissions of MAC Physical Data Blocks (PDUs) in the buffer, HARQ feedback for MAC PDUs in the buffer, current redundancy version, etc. Each HARQ process is distinguished by a HARQ process ID.

[0085] Meanwhile, the HARQ-ACK codebook is broadly defined into three codebook types, such as Type-1, Type-2, and Type-3, according to the configuration method of the HARQ-ACK bit (payload). In the case of the Type-1 codebook, the HARQ-ACK payload is configured by combining a set of candidate HARQ-ACK timings (K1) and a set of candidate PDSCH occasions (SLIV) (set for each cell) (e.g., a codebook of semi-statically fixed size based on RRC signaling). In the case of the Type-2 codebook, the size of the codebook is dynamically changed according to the number of PDSCHs actually scheduled or the number of corresponding resource allocations (e.g., downlink assignment index (DAI)). In the case of the Type-3 codebook, the HARQ-ACK payload is configured by mapping the HARQ-ACK bit corresponding to each HARQ process number (HPN) according to the maximum number of HARQ processes (set for each cell) (e.g., one-shot A / N reporting). In recent NR standards, an Enhanced Type-3 codebook has been added as one of the Type-3 codebooks. In order to reduce signaling overhead, the Enhanced Type-3 codebook does not report HARQ-ACK bits for all cells / HPNs at once, but reports HARQ-ACK bits for a subset of all cells / HPNs designated by the base station at once. A subset of cells / HPNs associated with the Enhanced Type-3 codebook is configured in the terminal by higher layer signaling, and then one of the subsets configured in the terminal is designated by DCI that triggers the Enhanced Type-3 codebook. The terminal can report HARQ-ACK for cells / HPNs belonging to the designated subset.

[0086] In the case of a Type-1 codebook, specifically, a set of multiple (e.g., N) candidate K1 values ​​is set (for each cell), and for each K1 value, all combinations of SLIVs that can be transmitted (or scheduled to be transmitted) in DL slots previous to the A / N transmission slot of K1 slots are calculated, and an A / N sub-payload corresponding to that DL slot (including determining the position / sequence of the A / N bits corresponding to each SLIV that can be transmitted in that slot) is constructed (this is defined as "SLIV pruning"), and this A / N sub-payload is concatenated for the N K1 values ​​to construct the entire A / N codebook, and at this time, the set of (N) DL slots corresponding to each K1 value is defined as a bundling window corresponding to the A / N transmission slot.

[0087] In the case of the Type-2 HARQ-ACK codebook, a codebook for transmitting HARQ-ACK information to the same PUCCH / PUSCH is defined based on a counter DAI (downlink assignment indicator) (C-DAI) and a total DAI (T-DAI) value indicated in an actually transmitted PDCCH. That is, the codebook is configured based on PDCCH information actually transmitted to the terminal. If the terminal fails to detect a specific PDCCH, it transmits a NACK to the bit corresponding to the PDCCH among bits defined in the codebook. In this case, the terminal can recognize whether or not the PDCCH detection has failed based on the C-DAI and T-DAI values. The C-DAI is a cumulative number of {serving cell index, PDCCH monitoring occasion}-pairs for which PDSCH reception is provided, including the current serving cell and the current PDCCH monitoring occasion. First, for multiple PDSCH receptions for the same {serving cell index, PDCCH monitoring opportunity} pair, the PDSCH that starts receiving first is counted first (assigned a lower C-DAI value). Next, if there are multiple pairs with the same PDCCH monitoring opportunity index among different {serving cell index, PDCCH monitoring opportunity} pairs, the pair with the lower serving cell index is counted first. Next, if there are multiple pairs with the same serving cell index among different {serving cell index, PDCCH monitoring opportunity} pairs, the PDCCH monitoring opportunity with the lower index is counted first.

[0088] In the case of a Type-3 codebook, one of the following modes is set by the BS to the UE: Mode 1, which feeds back NDI corresponding to HARQ-ACK, and Mode 2, which feeds back only HARQ-ACK without NDI. When set to Mode 1, the UE operates to feed back NDI (indicated by DCI) corresponding to HARQ-ACK for PDSCH reception of each HARQ Process Number (HPN). On the other hand, when set to Mode 2, the UE feeds back only HARQ-ACK for PDSCH reception of each HPN.

[0089] 6 illustrates a PUSCH transmission process. Referring to FIG. 6, a UE detects a PDCCH in slot #n. Here, the PDCCH includes uplink scheduling information (e.g., DCI format 0_0, 0_1). DCI format 0_0, 0_1 includes the following information:

[0090] - Frequency domain resource assignment: Indicates the RB set assigned to the PUSCH.

[0091] - Time domain resource assignment: indicates the slot offset K2, the starting position (e.g., symbol index) and length (e.g., number of OFDM symbols) of the PUSCH within the slot. The starting symbol and length are indicated by the Start and Length Indicator Value (SLIV) or are indicated respectively.

[0092] Thereafter, the terminal transmits a PUSCH in slot #(n+K2) according to the scheduling information of slot #n, where the PUSCH includes a UL-SCH TB.

[0093] Carrier aggregation

[0094] NR can merge multiple uplink / downlink carriers (i.e., carrier merging) to support wider uplink / downlink bandwidth. Carrier merging allows signals to be transmitted / received from multiple carriers. When carrier merging is applied, each carrier (see Figure A2) is called a component carrier (CC). CCs may be adjacent or non-adjacent to each other in the frequency domain. The bandwidth of each CC is defined independently. Asymmetric carrier merging, where the number of UL CCs and the number of DL CCs are different, is also possible.

[0095] - PCell (Primary Cell): In the case of a terminal configured for carrier merging, a cell operating on a primary frequency (e.g., Primary Component Carrier (PCC)) on which the terminal performs an initial connection establishment procedure or initiates a connection re-establishment procedure. In the case of DC (Dual Connectivity), a MCG (Master Cell Group) cell operating on a primary frequency on which the terminal performs an initial connection establishment procedure or initiates a connection re-establishment procedure.

[0096] - SCell (Secondary Cell): For a terminal configured with carrier aggregation, this is a cell that provides radio resources in addition to the special cell.

[0097] - PSCell (Primary SCG Cell): In the case of DC, a Secondary Cell Group (SCG) cell to which the UE randomly connects when performing RRC reconfiguration and synchronization processes.

[0098] - Special Cell (SpCell): In case of DC, the special cell points to a PCell of the MCG or a PSCell of the SCG. Otherwise (i.e., non-DC), the special cell points to a PCell.

[0099] - Serving Cell (ServCell): A cell configured for a terminal in the RRC_CONNECTED state. If CA / DA is not configured, there is only one serving cell (i.e., PCell). If CA / DA is configured, the serving cell indicates a cell set including the special cell and all SCells.

[0100] Meanwhile, the control information can be configured to be transmitted and received only by a specific cell. As an example, UCI is transmitted by a special cell (e.g., PCell). When an SCell (hereinafter, PUCCH-SCell) in which PUCCH transmission is permitted is configured, UCI can also be transmitted by the PUCCH-SCell. As another example, the base station allocates a scheduling cell (set) to reduce the complexity of PDCCH BD (blinding decoding) at the terminal side. For PDSCH reception / PUSCH transmission, the terminal performs PDCCH detection / decoding only in the scheduling cell. Also, the base station transmits PDCCH only in the scheduling cell (set). For example, PDCCH for downlink allocation is transmitted by cell #0 (i.e., scheduling cell), and its PDSCH is transmitted by cell #2 (i.e., scheduled cell) (Cross-Carrier Scheduling, CCS). The scheduling cell (set) is configured by a terminal-specific, terminal-group-specific, or cell-specific manner. The scheduling cell includes a special cell (eg, a PCell).

[0101] A carrier indicator field (CIF) is used for CCS (Cross-Carrier Scheduling). The CIF is semi-statically disabled / enabled by terminal-specific (or terminal group-specific) higher layer (e.g., Radio Resource Control, RRC) signaling. The CIF field is an x-bit field (e.g., x=3) in the PDCCH (i.e., DCI) and is used to indicate the (serving) cell index of the scheduled cell.

[0102] - CIF disabled: There is no CIF in the PDCCH. The PDCCH on the scheduling cell allocates PDSCH / PUSCH resources on the same cell, i.e. the scheduling cell is the same as the scheduled cell.

[0103] - CIF enabled: CIF exists in PDCCH. The scheduling PDCCH allocates PDSCH / PUSCH resources in one cell among multiple cells using CIF. The scheduling cell is the same as or different from the scheduled cell. PDSCH / PUSCH means PDSCH or PUSCH.

[0104] FIG. 7 is a diagram for explaining carrier merging. In FIG. 7, it is assumed that three cells are merged. When CIF is disabled, in each cell, only the PDCCH that schedules its own PDSCH / PUSCH is transmitted (self-carrier scheduling, SCS). On the other hand, when CIF is enabled by terminal-specific (or terminal-group-specific or cell-specific) higher layer signaling and cell A is set as a scheduling cell, cell A transmits not only the PDCCH that schedules cell A's PDSCH / PUSCH, but also the PDCCH that schedules the PDSCH / PUSCH of other cells (i.e., scheduled cells) (cross-carrier scheduling, CCS). In this case, cell B / C does not transmit the PDCCH that schedules its own cell.

[0105] NR-shared spectrum / unlicensed band (NR-U) operation

[0106] FIG. 8 is a diagram illustrating a wireless communication system supporting an unlicensed band. For convenience, a cell operating in a licensed band (hereinafter, L-band) is defined as an LCell, and a carrier of the LCell is defined as a (DL / UL) LCC (Licensed Component Carrier). A cell operating in an unlicensed band (hereinafter, U-band) is defined as an UCell, and a carrier of the UCell is defined as a (DL / UL) UCC (Unlicensed Component Carrier). A cell's carrier refers to the operating frequency (e.g., center frequency) of the cell. A cell / carrier (e.g., Component Carrier, CC) is collectively referred to as a cell.

[0107] When carrier aggregation (CA) is supported, one terminal can transmit and receive signals to and from a base station through multiple aggregated cells / carriers. When multiple CCs are configured in one terminal, one CC is set as a PCC (Primary CC) and the remaining CCs are set as SCCs (Secondary CCs). Specific control information / channels (e.g., CSS PDCCH, PUCCH) are set to be transmitted and received only through the PCC. Data is transmitted and received through the PCC / SCC. FIG. 8(a) illustrates an example in which a terminal and a base station transmit and receive signals through an LCC and a UCC (non-standalone (NSA) mode). In this case, the LCC is set as a PCC and the UCC is set as an SCC. When multiple LCCs are configured in a terminal, one specific LCC is set as a PCC and the remaining LCCs are set as SCCs. FIG. 8(a) corresponds to LAA in a 3GPP LTE system. Figure 8(b) illustrates an example in which a terminal and a base station transmit and receive signals via one or more UCCs without an LCC (SA (Standalone) mode). In this case, one of the UCCs is configured as a PCC, and the remaining UCCs are configured as SCCs. As a result, the NR UCell supports PUCCH, PUSCH, PRACH transmission, etc. In the unlicensed band of the 3GPP NR system, both the NSA mode and the SA mode are supported.

[0108] Unless otherwise stated, the following definitions apply to terms used in this specification.

[0109] - Channel: A channel is a set of consecutive RBs in a shared spectrum where a channel access process is performed. It refers to a carrier or a part of a carrier.

[0110] - Channel Access Procedure (CAP): A procedure for evaluating channel availability based on sensing to determine whether other communication nodes are using the channel before transmitting a signal. The basic unit for sensing is T slThe sensing slot has a duration of 9 us. The base station or the terminal senses the channel during the sensing slot, and the power detected for at least 4 us within the sensing slot is equal to or greater than the energy detection threshold X Thresh If it is smaller, the sensing slot period T sl is considered to be idle. Otherwise, the sensing slot period T sl =9us is considered busy. CAP is also known as LBT (Listen-Before-Talk).

[0111] - Channel occupancy: refers to the corresponding transmission on a channel by a base station / terminal after performing a channel access procedure.

[0112] - Channel Occupancy Time (COT): This refers to the total time that the base station / terminal and any base station / terminal sharing the channel occupancy can transmit on the channel after the base station / terminal performs the channel connection process. When determining the COT, if the transmission gap is 25us or less, the gap period is also counted in the COT. The COT is shared for transmission between the base station and the corresponding terminal.

[0113] - DL transmission burst: is defined as a set of transmissions from a base station with no gaps of more than 16us. Transmissions from a base station separated by gaps of more than 16us are considered to be individual DL transmission bursts. The base station does not sense channel availability within a DL transmission burst and transmits after the gap.

[0114] - UL transmission burst: is defined as a set of transmissions from a terminal with no gaps longer than 16us. Transmissions from a terminal separated by gaps longer than 16us are considered as individual UL transmission bursts. The terminal does not sense channel availability within a UL transmission burst and transmits after the gap.

[0115] - Detection burst: refers to a DL transmission burst that includes a set of signals and / or channels bounded within a (time) window and associated duty cycle. In an LTE-based system, a detection burst is a base station initiated transmission that includes PSS, SSS, and CRS (cell-specific RS), and also includes non-zero power CSI-RS. In an NR-based system, a detection burst is a base station initiated transmission that includes at least SS / PBCH blocks, and also includes CORESET for PDCCH that schedules PDSCH with SIB1, PDSCH carrying SIB1, and / or non-zero power CSI-RS.

[0116] FIG. 9 illustrates a method of occupying resources in an unlicensed band. According to regional regulations for unlicensed bands, a communication node in an unlicensed band must determine whether other communication nodes are using the channel before transmitting a signal. Specifically, a communication node can first perform carrier sensing (CS) before transmitting a signal to determine whether other communication nodes are transmitting signals. A case where it is determined that other communication nodes are not transmitting signals is defined as a case where a clear channel assessment (CCA) is confirmed. If there is a CCA threshold set by a predetermined or higher layer (e.g., RRC) signaling, a communication node determines the channel state as busy when energy higher than the CCA threshold is detected in the channel, and otherwise determines the channel state as idle. For reference, in the Wi-Fi standard (802.11ac), the CCA threshold is specified as -62 dBm for non-Wi-Fi signals and -82 dBm for Wi-Fi signals. If the channel state is determined to be idle, the communication node can start transmitting signals on the UCell. The above series of processes is called LBT (Listen-Before-Talk) or CAP (Channel Access Procedure). LBT and CAP can be used interchangeably.

[0117] Table 6 illustrates the channel access procedure (CAP) supported in NR-U.

[0118] [Table 6]

[0119] Multi-cell Scheduling DCI

[0120] NR supports broad spectrum in various frequency ranges. The re-farming of frequency bands used in previous generations is expected to increase the availability of advanced spectrum for 5G. In particular, for the low frequency band FR1, available spectrum blocks tend to become more fragmented and dispersed. For FR2 bands and some FR1 bands, the available spectrum becomes wider, necessitating the operation of multiple carriers / cells within the band. It is necessary to improve throughput and coverage by using such dispersed spectrum bands or wider bandwidth spectrum in a more power-efficient and flexible manner.

[0121] When scheduling data across multiple cells, including intra-band and inter-band cells, it is important to increase flexibility and spectrum / power efficiency. In the current 5G NR scheduling method, DCI can only schedule PUSCH / PDSCH for one cell. However, it is expected that the need for simultaneous scheduling of multiple cells will increase in the future due to spectrum expansion / modification, etc. In order to reduce control overhead due to scheduling, it is advantageous to schedule PUSCH / PDSCH for multiple cells using one DCI.

[0122] Thus, in future, in carrier aggregation (CA) situations where multiple cells are configured, in order to reduce the DCI overhead for PDSCH / PUSCH scheduling, Rel-18 will consider a multi-cell scheduling scheme that simultaneously schedules multiple (serving) cells / CCs (and thus PDSCH / PUSCH transmissions) with a single DCI.

[0123] Here, we propose an efficient HARQ-ACK (for convenience, referred to as "A / N") feedback configuration and transmission operation method considering a situation in which multiple PDSCHs on multiple cells are simultaneously scheduled based on the above-mentioned multi-cell DCI. (As explained in FIG. 5 / 6), the meanings of the terms used are summarized as follows. Also, "cell" may refer to a BWP configured / indicated (active) in the cell.

[0124] K0: Slot interval between a DCI (or PDCCH) transmission slot and a PDSCH transmission slot (scheduled from that DCI)

[0125] - SLIV (start symbol and length indicator value) (PDSCH occasion): start symbol and symbol duration (or end symbol) information of PDSCH

[0126] - Mapping type: Information on whether the DMRS symbol position of the PDSCH is determined based on the symbol index within a slot period or based on the symbol index within a PDSCH period

[0127] - Time domain resource assignment (TDRA) table: consists of multiple {K0, SLIV, mapping type} combinations (configured by RRC) (one combination is mapped to each of multiple rows in the table), and a specific row is indicated by the corresponding DCI field

[0128] - K1: Slot interval between a PDSCH transmission slot and a HARQ-ACK transmission slot (for that PDSCH reception)

[0129] Hereinafter, the multi-cell scheduling DCI is also referred to as a multi-cell DCI or simply DCI, and includes at least one of a DL grant DCI for scheduling a PDSCH and a UL grant DCI for scheduling a PUSCH.

[0130] [1] Type-1 HARQ-ACK codebook construction considering multi-cell PDSCH scheduling

[0131] 1) Conventional operation

[0132] In the case of a conventional Type-1 codebook, with a set of multiple (e.g., N) candidate K1 values ​​configured, a combination of all PDSCH occasions (SLIVs) that can be transmitted in the previous DL slots of K1 slots from the A / N transmission slot is calculated for each K1 value (set for each serving cell), and an A / N sub-payload (including determining the position / sequence of the A / N bit corresponding to each SLIV) corresponding to that DL slot is constructed (this is defined as "SLIV pruning"), and this A / N sub-payload is concatenated for the N K1 values ​​to construct the entire A / N codebook (see Section 9.1.2 of 3GPP TS 38.213 V16.2.0). At this time, the set of (N) DL slots corresponding to each K1 value is defined as a bundling window corresponding to the A / N transmission slot.

[0133] 2) Suggested action

[0134] A plurality of SLIV combinations for a plurality of cells (one or more) are mapped / configured in each of a plurality of (multiple-SLIV) rows in the (extended) TDRA table for the multi-cell (PDSCH scheduling), and the TDRA indication field included in the DCI indicates one (multiple-SLIV) row based on the table. For example, the first row of the TDRA table is configured with a first SLIV combination, the second row is configured with a second SLIV combination, ..., the Nth row is configured with an Nth SLIV combination by higher layer signaling. Each SLIV combination includes one or more {K0, SLIV, mapping type}-parameter sets. For example, a specific row of the TDRA table is configured with {K0, SLIV, mapping type}-parameter set #1, {K0, SLIV, mapping type}-parameter set #2, {K0, SLIV, mapping type}-parameter set #3, ..., {K0, SLIV, mapping type}-parameter set #M for scheduling for M cells.

[0135] In the case of a K1 indication field, when only one K1 field is configured in the multi-cell DCI, only one K1 value to be applied based on a specific PDSCH #1 on a specific cell (among the multiple cells scheduled by that DCI) is indicated by that K1 field. In this case, it is determined to transmit HARQ-ACK feedback for all PDSCHs (on the multiple cells scheduled by that DCI), including PDSCH #1, by applying the K1 value indicated by the DCI to PDSCH #1 (i.e., the HARQ-ACK feedback transmission time) determined by the PUCCH (sub-)slot.

[0136] In the case of the above-mentioned PDSCH #1, Alt 1) the PDSCH on the cell with the lowest cell index (or highest cell index) among the multiple cells scheduled (by the same multi-cell DCI) is determined, or Alt 2) the PDSCH with the latest transmission ending symbol time (or transmission starting symbol time) among the multiple PDSCHs on the multiple cells scheduled (by the same multi-cell DCI) is determined.

[0137] In Alt 2, if there are multiple PDSCHs (on multiple scheduled cells) with the latest end symbol instants (or latest start symbol instants), Alt A) the PDSCH transmitted based on the smallest SCS (or the largest SCS) among the multiple PDSCHs is determined, or Alt B) the PDSCH on the cell with the lowest cell index (or the highest cell index) among the multiple PDSCHs is determined.

[0138] 3) Proposal 1-1

[0139] When PDSCH scheduling based on the multi-cell DCI is configured, the SLIV pruning process is performed for each cell for Type-1 A / N codebook configuration, and for a cell that is a target of multi-cell DCI scheduling, only the SLIV related to that cell (out of multiple SLIVs) that is mapped / set to each multi-SLIV column in the extended TDRA table is extracted and included in the SLIV set applied to the SLIV pruning process for that cell.

[0140] 4) Proposal 1-2

[0141] When PDSCH scheduling based on the multi-cell DCI is configured, in determining the bundling window for each cell for the Type-1 A / N codebook configuration, for a cell that is the target of multi-cell DCI scheduling, if the difference (counted based on PUCCH (sub-) slots) between the reception time of the PDSCH (SLIV) on that cell and the reception time of the PDSCH #1 (SLIV) is d slots for each of the (candidate) K1 values ​​(and the (candidate) multi-SLIV) that are set indicatively by the multi-cell DCI, the bundling window corresponding to that cell is determined based on a set of {K1+d} values ​​obtained by adding this difference to K1.

[0142] Specifically, for a cell that is a target of the above-mentioned multi-cell DCI scheduling, for each of the (candidate) K1 values ​​(and the (candidate) multi-SLIV) set indicatively by the DCI, if the difference (counted based on the PUCCH (sub-) slot) between the last PUCCH (sub-) slot overlapping with the PDSCH (SLIV) reception time point (e.g., the slot on the cell where the PDSCH is transmitted or its PDSCH transmission symbol) on the cell and the last PUCCH (sub-) slot overlapping with the PDSCH #1 (SLIV) reception time point (e.g., the slot on the cell where PDSCH #1 is transmitted or its PDSCH #1 transmission symbol) is d slots, a bundling window corresponding to the cell is determined based on a set of {K1+d} values ​​obtained by adding this difference to K1.

[0143] [2] Type-2 HARQ-ACK codebook construction considering multi-cell PDSCH scheduling

[0144] 1) Suggested action

[0145] In a situation where PDSCH scheduling based on the multi-cell DCI is configured, in the case of a Type-2 codebook, a C / T (counter / total)-DAI value is determined and signaled independently for each of the conventional single-cell (PDSCH scheduling) DCI (type) and the multi-cell (PDSCH scheduling) DCI (type) (i.e., the procedure / sum of the scheduled DCI / PDSCH for each DCI type is determined / signaled independently) (in other words, the single-cell DCI determines and signals a DAI value only for the single-cell DCI, and the multi-cell DCI determines and signals a DAI value only for the multi-cell DCI).

[0146] Another method is a structure in which the C / T-DAI value is determined and signaled independently for each of the cases where only one PDSCH (on a cell) is scheduled by single-cell DCI or multi-cell DCI (single-cell case) and where multiple PDSCHs (on cells) are scheduled by multi-cell DCI (multiple-cell case) (i.e., the procedure / sum of the scheduled DCI / PDSCHs for each case is determined / signaled independently) (in other words, the DCI corresponding to the single-cell case determines and signals a DAI value only for the single-cell case, and the DCI corresponding to the multi-cell case determines and signals a DAI value only for the multiple-cell case).

[0147] In the case of the single-cell case mentioned above, Alt 1) includes only the case where the single-cell DCI or the multi-cell DCI indicates the transmission of one PDSCH (on a cell), or Alt 2) includes the case where the (single-cell DCI or) the multi-cell DCI indicates the transmission of (one or) multiple PDSCHs (on cells), of which the terminal actually receives only one PDSCH (on a cell). (In the latter Alt 2 case, the multiple-cell case mentioned above corresponds to the case where the multi-cell DCI indicates the transmission of multiple PDSCHs (on cells), of which the terminal actually receives two or more PDSCHs (on cells).)

[0148] 2) Proposal 2-1

[0149] (For reference, prior to the description of this proposal, the description of the Type-2 HARQ-ACK codebook described in relation to FIG. 5 can be referred to for understanding C(counter)-DAI (C-DAI for single-cell scheduling) defined in the conventional standard.)

[0150] A. When multiple (multiple-cell) DCIs including the multi-cell DCI are transmitted / received at the same time (e.g., PDCCH monitoring opportunity or slot), the C(counter)-DAI value corresponding to the multi-cell DCI (signaled by the DCI) is determined based on the lowest (or highest) cell index among the multiple cells scheduled by the multi-cell DCI.

[0151] For example, when two multi-cell DCIs are transmitted / received at the same time point (e.g., a PDCCH monitoring opportunity or a slot), when comparing the lowest (or highest) cell index among the cells scheduled by each DCI, the counter (DAI) value corresponding to the DCI that schedules a lower cell index is determined / signaled to a lower value. For example, when multiple DCIs received at the same time point include at least one multi-cell DCI, and the first DCI of at least one multi-cell DCI schedules {Cell A, Cell B, and Cell C}, and it is assumed that Cell A has a lower cell index than Cell B and Cell C. The second DCI received at the same time point as the first DCI may be a multi-cell DCI or a single-cell DCI. It is assumed that the cell with the lowest cell index among one or more cells scheduled by the second DCI is Cell D. If the cell index of Cell A < the cell index of Cell D, the C-DAI value of the first DCI is counted earlier (e.g., for the multi-cell scheduling of Cell A, Cell B, and Cell C), and then the C-DAI value of the second DCI is counted. If the cell index of Cell A > the cell index of Cell D, the C-DAI value of the second DCI is counted earlier, and then the C-DAI value of the first DCI is counted.

[0152] If the lowest (or highest) cell index scheduled by each DCI is the same, among the PDSCHs transmitted on the cell having that cell index, the counter (DAI) value corresponding to the DCI that schedules the PDSCH having an earlier transmission start (or earlier transmission end) symbol time point is determined / signaled to a lower value.

[0153] B. As another method, when multiple (multiple-cell) DCIs including the multi-cell DCI are transmitted / received at the same time (e.g., PDCCH monitoring opportunity or slot), the C-DAI value corresponding to the multi-cell DCI (signaled by that DCI) is determined based on the PDSCH with the earliest transmission starting symbol time (or transmission ending symbol time) among multiple PDSCHs on multiple cells scheduled by that multi-cell DCI.

[0154] For example, when two multi-cell DCIs are transmitted / received at the same time, when comparing the PDSCHs having the earliest start symbol time (or end symbol time) (among multiple PDSCHs on multiple cells) scheduled by each DCI, the counter (DAI) value corresponding to the DCI that schedules the PDSCH with the earlier start (or end) symbol time is determined / signaled to a lower value.

[0155] If the start (or end) symbol time of the PDSCH having the earliest start (or end) symbol time scheduled in each DCI is the same, the counter (DAI) value corresponding to the DCI that schedules the PDSCH transmitted on the cell with the lowest cell index among the PDSCHs is determined / signaled to a lower value.

[0156] C. As another method, when multiple (multiple-cell) DCIs including the multi-cell DCI are transmitted / received at the same time (e.g., PDCCH monitoring opportunity or slot), the C-DAI value corresponding to the multi-cell DCI (signaled by that DCI) is determined based on the PDSCH with the latest transmission starting symbol time (or transmission ending symbol time) among multiple PDSCHs on multiple cells scheduled by that multi-cell DCI.

[0157] For example, when two multi-cell DCIs are transmitted / received at the same time, when comparing the PDSCHs (among multiple PDSCHs on multiple cells) scheduled by each DCI with the latest start symbol time (or end symbol time), the counter (DAI) value corresponding to the DCI that schedules the PDSCH with the earlier start (or end) symbol time is determined / signaled to a lower value.

[0158] If the start (or end) symbol time of the PDSCH having the latest start (or end) symbol time scheduled in each DCI is the same, the counter (DAI) value corresponding to the DCI that schedules the PDSCH transmitted on the cell with the lower cell index among the PDSCHs is determined / signaled to a lower value.

[0159] 3) Proposal 2-2

[0160] As an example, in the multi-cell case, the number of A / N bits per each DAI value is determined taking into consideration at least one of the maximum number of cells (within the same PUCCH group) that can be scheduled together by one (multi-cell) DCI, the number of TBs (or codewords) supported per PDSCH (e.g., 1 or 2), and whether or not spatial bundling for A / N is configured.

[0161] For the multi-cell case (and / or multi-cell DCI), the number of A / N bits corresponding to one DAI (for convenience, referred to as the "DAI A / N size for multi-cell case") is determined based on the maximum number of cells that can be scheduled simultaneously by a single multi-cell DCI when spatial (domain) A / N bundling between (two) TBs transmitted via the same PDSCH is configured (or when it is configured that only a single TB transmission is possible for all of the target cells for multi-cell DCI scheduling), and when spatial bundling is not configured, it is determined based on the maximum number of TBs that can be scheduled simultaneously by a single multi-cell DCI (taking into account all cell combinations that can be scheduled simultaneously and the maximum number of TBs (transmittable) configured for each cell).

[0162] For example, referring to FIG. 10, for all cells that can be scheduled by the multi-cell DCI, if the number of TBs (or CWs) per PDSCH is set to 1 (A05), or if a cell with 2 TBs per PDSCH is included but spatial A / N bundling between TBs is configured for the cell (A10), the DAI A / N size is determined based on the maximum number of cells that can be scheduled by one multi-cell DCI. For example, referring to FIG. 11, assuming that M co-scheduled cell combinations are configured in the UE and the multi-cell DCI performs multi-cell scheduling by any one of the M co-scheduled cell combinations, the maximum number of cells that can be scheduled by one multi-cell DCI is Max {1st value, 2nd value, 3rd value,...., M-th value}. As an example, assuming that Max{1st value, 2nd value, 3rd value,...., M-th value}=X, the DAI A / N size is X-bit. For example, if X-bits are allocated for each counter DAI value and a HARQ-ACK codebook (e.g., type-2 HARQ-ACK codebook) is configured for all C1 counter DAI values, the HARQ-ACK codebook includes C1*X A / N bits. This means that if the number of TBs (or CWs) per PDSCH is set to 1 for all cells that can be scheduled by multi-cell DCI (A05, Yes), or if a cell with 2 TBs per PDSCH is included but spatial A / N bundling between TBs is configured for that cell (A10, Yes), one A / N bit is allocated for each scheduled cell for 1 DCI.

[0163] If the number of TBs per PDSCH is 2 among the cells that can be scheduled by the multi-cell DCI and at least one cell is included in which spatial A / N bundling between TBs is not configured (A10, No), the DAI A / N size is determined based on the maximum number of TBs that can be scheduled by one multi-cell DCI. For example, assuming that the maximum number of TBs that can be scheduled by one multi-cell DCI is Y, if a HARQ-ACK codebook (e.g., a type-2 HARQ-ACK codebook) is configured for all C1 counter DAI values, the HARQ-ACK codebook includes C1*Y A / N bits. For example, in Fig. 11, assuming that 2-TB is configured for Cell #1 and Cell #3, 1-TB is configured for other cells, and spatial bundling is not configured for (at least one of) Cell #1 and Cell #3, the number of TBs that can be scheduled by Cell combination 1 is 2+2+1=5, the number of TBs that can be scheduled by Cell combination 2 is 2, the number of TBs that can be scheduled by Cell combination 3 is 1+2+1=4, and the number of TBs that can be scheduled by Cell combination M is 1+1+1+1=4. In this way, the DAI A / N size is determined based on the cell combination with the largest number of schedulable TBs among M cell combinations configured in the terminal.

[0164] 4) Proposal 2-3

[0165] When independent DAI counting is performed for the above-mentioned single-cell case (and / or single-cell DCI; for convenience, the single-cell case and single-cell DCI are collectively referred to as the single-cell case) and the multiple-cell case (or multiple-cell DCI; for convenience, the multiple-cell case and multiple-cell DCI are collectively referred to as the multiple-cell case), the terminal may configure separate sub-codebooks for each of the single-cell case and the multiple-cell case, and operates to configure the entire codebook by concatenating sub-codebook #1 corresponding to the single-cell case with sub-codebook #2 corresponding to the multiple-cell case (or, conversely, configure the entire codebook by appending sub-codebook #1 to sub-codebook #2). (i) As an example, sub-codebook #1 includes an A / N-bit for a single-cell DCI and an A / N-bit for a multi-cell DCI that schedules a PDSCH for only one cell, and sub-codebook #2 includes an A / N-bit for a multi-cell DCI that schedules a PDSCH for at least two cells. (ii) As another example, sub-codebook #1 includes an A / N-bit for a single-cell DCI, and sub-codebook #2 includes an A / N-bit for a multi-cell DCI that schedules a PDSCH for only one cell, and an A / N-bit for a multi-cell DCI that schedules a PDSCH for at least two cells.

[0166] Meanwhile, (in a CA situation), CB group (CBG)-based PDSCH transmission (DCI for scheduling this) is configured in a specific cell (such PDSCH scheduling is referred to as a CBG-PDSCH case), and the number of A / N bits corresponding to the PDSCH / DCI (for convenience, referred to as the "DAI A / N size for CBG-PDSCH case") is determined to be the maximum number of CBGs that can be configured / transmitted on a single PDSCH configured in the cell, and / or an operation of simultaneously scheduling multiple TDMed PDSCHs (on that cell) based on a single DCI is configured in a specific cell (such PDSCH scheduling is referred to as a multi-PDSCH case), and the number of A / N bits corresponding to the DCI (for convenience, referred to as the "DAI A / N size for multi-PDSCH case") is determined to be the maximum number of CBGs that can be configured / transmitted on a single PDSCH configured in the cell. The CBG-PDSCH case and / or the multi-PDSCH case and the multi-cell case are both set, and the DAI counting and sub-codebook configuration are performed in the following manner.

[0167] - Opt 1: Independent DAI counting may be performed for the multi-cell case and the CBG-PDSCH case (or the multi-PDSCH case) to construct a separate sub-codebook for each case. In this case, the entire codebook may be constructed by appending sub-codebook #2 corresponding to the CBG-PDCH case (or the multi-PDSCH case) to sub-codebook #1 corresponding to the multi-cell case (or, conversely, appending sub-codebook #1 to sub-codebook #2).

[0168] - Opt 2: A common DAI counting is performed for the multiple-cell case and the CBG-PDCH case (or the multiple-PDSCH case) (in other words, the DCI corresponding to the multiple-cell case determines / signals a DAI value taking into consideration not only the multiple-cell case but also the CBG-PDCH case (or the multiple-PDSCH case), and the DCI corresponding to the CBG-PDCH case (or the multiple-PDSCH case) determines / signals a DAI value taking into consideration not only the CBG-PDCH case (or the multiple-PDSCH case) but also the multiple-cell case). One integrated sub-codebook can be configured for the two cases, and in this case, the number of A / N bits corresponding to one DAI is determined to be the maximum value among the DAI A / N size for the multiple-cell case and the DAI A / N size for the CBG-PDSCH case (or the DAI A / N size for the multiple-PDSCH case).

[0169] On the other hand, in a situation where a Type-2 codebook is configured in a specific (PUCCH) cell group, if multi-cell DCI based PDSCH scheduling is configured in multiple cells belonging to the cell group, in order to reduce the complexity of the A / N codebook configuration from the perspective of the terminal, a restriction is imposed such that CBG-based PDSCH transmission is not configured in any cell in the cell group, and in a situation where the Type-1 codebook is configured in a specific number of cells, if multi-cell DCI based PDSCH scheduling is configured in specific number of cells, in order to reduce the complexity of the A / N codebook configuration from the perspective of the terminal, a restriction is imposed such that CBG-based PDSCH transmission is not configured in any cell of the multiple cells.

[0170] 5) Proposal 2-4

[0171] For the multi-cell case (or multi-cell DCI), the procedure of A / N bit mapping within the A / N payload corresponding to one DAI is determined in the following manner.

[0172] - Opt 1: A / N bits corresponding to TBs scheduled in DCI (or TBs actually received by the UE) are mapped sequentially in the order of TB index first - cell index second. The procedure means ascending or descending order. For example, the UE first maps A / N bits to all scheduled TBs of the cell with the lowest cell index in TB index order (e.g., ascending order of TB index), and when mapping of A / N bits to all TB indexes of the cell is completed, the UE first maps A / N bits to scheduled TBs of the cell with the second lowest cell index in TB index order.

[0173] If spatial bundling is configured (or if only a single TB transmission is possible for all cells subject to multi-cell DCI scheduling), the A / N bits corresponding to the PDSCHs scheduled in the DCI (or among them, the PDSCHs actually received by the terminal) are mapped sequentially according to the cell index order.

[0174] For example, in FIG. 12, assume that Cell A with cell index 1, Cell B with cell index 3, and Cell C with cell index 5 are scheduled together by DCI, and that a maximum of 2-TB is set for each of Cell A and Cell B, and a maximum of 1-TB is set for Cell C, and spatial bundling is set only for Cell B. Also assume that the number of TBs actually scheduled by DCI is 1-TB, 2-TB, and 1-TB for Cell A, Cell B, and Cell C, respectively. (Also assume that the DAI A / N size for the multi-cell case described in Proposal 2-2 is 5-bit for convenience of explanation.) FIG. 12(a) is an example of Opt 1. Referring to FIG. 12(a), the A / N bit for TB1 of Cell A, which has the lowest cell index, is mapped first. Since TB2 of Cell A was not scheduled, the A / N bit for TB of Cell B is mapped next. Since spatial bundling is configured in Cell B, the A / N bit for TB1 and the A / N bit for TB2 are bundled (for example, AND operation) into one A / N bit. Next, the A / N bit for TB1 of Cell C is mapped.

[0175] - Opt 2: A / N bits corresponding to PDSCHs (cells) scheduled in DCI (or among them, PDSCHs (cells) actually received by the UE) are mapped sequentially according to the cell index order by the maximum TB number set for each cell. The order means ascending or descending order.

[0176] If spatial bundling is configured (or configured such that only a single TB transmission is possible for all cells subject to multi-cell DCI scheduling), the A / N bits corresponding to the PDSCHs scheduled in the DCI (or among them, the PDSCHs actually received by the terminal) are mapped sequentially according to the cell index order.

[0177] FIG. 12(b) is an example of Opt 2. Referring to FIG. 12(b), the A / N bit for TB1 of Cell A, which has the lowest cell index, is mapped first. Since the maximum TB number set for Cell A is 2, the A / N bit for TB2 of Cell A can be mapped even if TB2 is not actually scheduled. The A / N bit for TB2 is set to NACK / DTX. Next, the A / N bit for the TB of Cell B is mapped. Although the maximum TB number set for Cell B is 2, the A / N bit for TB1 and the A / N bit for TB2 are bundled (e.g., AND operation) into one A / N bit because spatial bundling is set for Cell B. Next, the A / N bit for TB1 of Cell C is mapped.

[0178] - Opt 3: (When the number of A / N bits corresponding to one DAI is determined based on the number of cells in the entire candidate cell set that can be scheduled by the multi-cell DCI) Regardless of the PDSCH (cell) that is actually scheduled (received), the A / N bits corresponding to the cells belonging to the entire candidate cell set (for the maximum TB number set for each cell) are mapped sequentially according to the cell index order. The procedure means ascending or descending order. For example, even if only a combination of some cells belonging to the candidate cell set is scheduled by DCI, the A / N bits for all the cells belonging to the candidate cell set are mapped according to the cell index order.

[0179] If spatial bundling is configured (or configured such that only a single TB transmission is possible for all cells subject to multi-cell DCI scheduling), the A / N bits corresponding to the scheduled / received PDSCH for cells belonging to the entire candidate cell set are mapped sequentially according to the cell index order, regardless of the actually scheduled (received) PDSCH (cell).

[0180] 13 is a diagram illustrating an example of signal reception by a terminal based on at least a portion of the above-described embodiment. The above content can be referred to for understanding FIG. 13 without any special explanation.

[0181] Referring to FIG. 13, a UE may receive downlink control information (DCI) through a physical downlink control channel (PDCCH) (1305).

[0182] The UE may receive, based on the DCI, at least one transport block (TB) through a physical downlink shared channel (PDSCH) in at least one of a plurality of cells configured in the UE (1310).

[0183] The UE may transmit hybrid automatic repeat request-acknowledgement (HARQ-ACK) information for the at least one TB (1315).

[0184] The first DCI may support multi-cell scheduling based on the plurality of serving cells.

[0185] The number of acknowledgement / negative-acknowledgement (ACK / NACK) bits included in the HARQ-ACK information may be determined based on at least one of a maximum number of cells that can be co-scheduled by the DCI, or a maximum number of TBs that can be received through cells co-scheduled by the DCI.

[0186] Based on the fact that in at least one of the cells that can be co-scheduled by the DCI, the maximum number of TBs per PDSCH is 2 and spatial bundling is not configured, the number of ACK / NACK bits included in the HARQ-ACK information is determined based on the maximum number of TBs that can be received via the cells that can be co-scheduled by the DCI.

[0187] Based on the maximum number of TBs per PDSCH being 1 or spatial bundling being configured in each of the cells that can be scheduled together by the DCI, the number of ACK / NACK bits included in the HARQ-ACK information is determined based on the maximum number of cells that can be scheduled together by the DCI.

[0188] The maximum number of cells that can be co-scheduled by the DCI is related to the cell combination that includes the most cells among the cell combinations that can be co-scheduled by the DCI.

[0189] Within the HARQ-ACK information, the ACK / NACK bits are aligned based on the serving cell index of the co-scheduled cells.

[0190] The DCI includes information about a downlink assignment index (DAI), which is determined based on a cell having a minimum serving cell index among cells co-scheduled by the DCI.

[0191] The HARQ-ACK information for the multi-cell scheduling is included in a second sub-codebook, and the HARQ-ACK information for the single-cell scheduling is included in a first sub-codebook.

[0192] A HARQ-ACK codebook is constructed based on the concatenation of the first sub-codebook and the second sub-codebook, for example, the second sub-codebook is appended to the end of the first sub-codebook.

[0193] The second sub-codebook is associated with a PDSCH scheduled by a multi-cell scheduling DCI in which two or more cells are actually scheduled, and the first sub-codebook is associated with a PDSCH scheduled by a multi-cell scheduling DCI and a single-cell scheduling DCI in which one cell is actually scheduled.

[0194] 14 is an example of a signal transmission by a base station based on at least a part of the above-described embodiment. The above content can be referred to for understanding FIG. 14 without special description.

[0195] Referring to FIG. 14, the base station transmits downlink control information (DCI) to the terminal via a physical downlink control channel (PDCCH) (1405).

[0196] The base station transmits at least one transport block (TB) via a physical downlink shared channel (PDSCH) in at least one of a plurality of cells configured for the terminal based on the DCI (1410).

[0197] The base station receives (1415) hybrid automatic repeat request-acknowledgement (HARQ-ACK) information for the at least one TB.

[0198] The DCI supports multi-cell scheduling based on the multiple cells.

[0199] The number of ACK / NACK (acknowledgement / negative-acknowledgement) bits included in the HARQ-ACK information is determined based on at least one of the maximum number of cells that can be co-scheduled by the DCI or the maximum number of TBs that can be transmitted via cells co-scheduled by the DCI.

[0200] Based on the fact that in at least one of the cells that can be co-scheduled by the DCI, the maximum number of TBs per PDSCH is 2 and spatial bundling is not configured, the number of ACK / NACK bits included in the HARQ-ACK information is determined based on the maximum number of TBs that can be transmitted via cells that are co-scheduled by the DCI.

[0201] Based on the maximum number of TBs per PDSCH being 1 or spatial bundling being configured in each of the cells that can be scheduled together by the DCI, the number of ACK / NACK bits included in the HARQ-ACK information is determined based on the maximum number of cells that can be scheduled together by the DCI.

[0202] The maximum number of cells that can be co-scheduled by the DCI is related to the cell combination that includes the most cells among the cell combinations that can be co-scheduled by the DCI.

[0203] Within the HARQ-ACK information, the ACK / NACK bits are aligned based on the serving cell index of the co-scheduled cells.

[0204] The DCI includes information about a downlink assignment index (DAI), which is determined based on a cell having a minimum serving cell index among cells co-scheduled by the DCI.

[0205] The HARQ-ACK information for the multi-cell scheduling is included in a second sub-codebook, and the HARQ-ACK information for the single-cell scheduling is included in a first sub-codebook.

[0206] One HARQ-ACK codebook is constructed based on the concatenation of the first sub-codebook and the second sub-codebook, for example, the second sub-codebook is appended to the end of the first sub-codebook.

[0207] The second sub-codebook is associated with a PDSCH scheduled by a multi-cell scheduling DCI in which two or more cells are actually scheduled, and the first sub-codebook is associated with a PDSCH scheduled by a multi-cell scheduling DCI and a single-cell scheduling DCI in which one cell is actually scheduled.

[0208] FIG. 15 illustrates a communication system 1 to which the present invention can be applied.

[0209] Referring to FIG. 15, the communication system 1 includes wireless devices, base stations, and networks. Here, the wireless devices refer to devices that communicate using wireless connection technology (e.g., 5G NR, LTE), and are also referred to as communication / wireless / 5G devices. The wireless devices include, but are not limited to, a robot 100a, vehicles 100b-1, 100b-2, an XR (eXtended Reality) device 100c, a handheld device (Hand-held Device) 100d, a home appliance 100e, an IoT (Internet of Thing) device 100f, and an AI server / device 400. For example, the vehicles include vehicles equipped with wireless communication functions, autonomous vehicles, vehicles capable of inter-vehicle communication, and the like. Here, the vehicles include UAVs (Unmanned Aerial Vehicles) (e.g., drones). XR devices include Augmented Reality (AR) / Virtual Reality (VR) / Mixed Reality (MR) devices, and are embodied in the form of Head-Mounted Devices (HMDs), Head-Up Displays (HUDs) mounted on vehicles, TVs, smartphones, computers, wearable devices, home appliances, digital billboards, vehicles, robots, etc. Portable devices include smartphones, smart pads, wearable devices (e.g., smart watches, smart glasses), computers (e.g., notebook computers, etc.), etc. Home appliances include TVs, refrigerators, washing machines, etc. IoT devices include sensors, smart meters, etc. For example, base stations and networks may also be embodied as wireless devices, and a specific wireless device 200a may operate as a base station / network node for other wireless devices.

[0210] The wireless devices 100a to 100f are connected to a network 300 via a base station 200. AI (Artificial Intelligence) technology is applied to the wireless devices 100a to 100f, and the wireless devices 100a to 100f are connected to an AI server 400 via the network 300. The network 300 is configured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g., NR) network. The wireless devices 100a to 100f can communicate with each other via the base station 200 / network 300, but can also communicate directly without going through the base station / network (e.g., sidelink communication). For example, the vehicles 100b-1 and 100b-2 can communicate directly (e.g., V2V (Vehicle to Vehicle) / V2X (Vehicle to everything) communication). Also, an IoT device (e.g., a sensor) can directly communicate with another IoT device (e.g., a sensor) or another wireless device 100a to 100f.

[0211] Wireless communication / connections 150a, 150b, and 150c are performed between the wireless devices 100a to 100f / base stations 200 and the base stations 200. Here, the wireless communication / connections are performed by various wireless connection technologies such as uplink / downlink communication 150a and sidelink communication 150b (or D2D communication) and communication between base stations 150c (e.g., relay, IAB (Integrated Access Backhaul) (e.g., 5G NR). Through the wireless communication / connections 150a, 150b, and 150c, the wireless devices and base stations, and the base stations and base stations can transmit / receive wireless signals to each other. For example, the wireless communication / connections 150a, 150b, and 150c can transmit / receive signals via various physical channels. To this end, based on various proposals of the present invention, any one of various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel coding / decoding, modulation / demodulation, resource mapping / demapping, etc.), and resource allocation processes is performed.

[0212] FIG. 16 illustrates a wireless device to which the present invention can be applied.

[0213] 16, a first wireless device 100 and a second wireless device 200 transmit and receive wireless signals according to various wireless access technologies (e.g., LTE, NR), where {first wireless device 100, second wireless device 200} corresponds to {wireless device 100x, base station 200} and / or {wireless device 100x, wireless device 100x} in FIG.

[0214] The first wireless device 100 includes one or more processors 102 and one or more memories 104, and further includes one or more transceivers 106 and / or one or more antennas 108. The processor 102 is configured to control the memory 104 and / or the transceiver 106 to implement the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein. For example, the processor 102 processes information in the memory 104 to generate a first information / signal, and then transmits a wireless signal including the first information / signal via the transceiver 106. The processor 102 also receives a wireless signal including a second information / signal via the transceiver 106, and then stores information obtained from signal processing of the second information / signal in the memory 104. The memory 104 is coupled to the processor 102 and stores various information related to the operation of the processor 102. For example, the memory 104 stores software code including instructions for performing some or all of the processes controlled by the processor 102 or for performing the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein. Here, the processor 102 and memory 104 are part of a communication modem / circuit / chip designed to implement a wireless communication technology (e.g., LTE, NR). The transceiver 106 is coupled to the processor 102 and transmits and / or receives wireless signals via one or more antennas 108. The transceiver 106 includes a transmitter and / or a receiver. The transceiver 106 may also be referred to as an RF (radio frequency) unit. In this specification, a wireless device may also refer to a communication modem / circuit / chip.

[0215] The second wireless device 200 includes one or more processors 202 and one or more memories 204, and further includes one or more transceivers 206 and / or one or more antennas 208. The processor 202 is configured to control the memory 204 and / or the transceiver 206 to implement the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein. For example, the processor 202 processes information in the memory 204 to generate a third information / signal, and then transmits a wireless signal including the third information / signal via the transceiver 206. The processor 202 also receives a wireless signal including a fourth information / signal via the transceiver 206, and then stores information obtained from the signal processing of the fourth information / signal in the memory 204. The memory 204 is coupled to the processor 202 and stores various information related to the operation of the processor 202. For example, the memory 204 stores software code including instructions for performing some or all of the processes controlled by the processor 202 or for performing the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein. Here, the processor 202 and memory 204 are part of a communication modem / circuit / chip designed to implement a wireless communication technology (e.g., LTE, NR). The transceiver 206 is coupled to the processor 202 and transmits and / or receives wireless signals via one or more antennas 208. The transceiver 206 includes a transmitter and / or a receiver. The transceiver 206 may also be referred to as an RF unit. In this specification, a wireless device may also refer to a communication modem / circuit / chip.

[0216] The hardware elements of the wireless device 100, 200 are described in more detail below. One or more protocol layers may be implemented by, but are not limited to, one or more processors 102, 202. For example, the one or more processors 102, 202 may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). The one or more processors 102, 202 may generate one or more Protocol Data Units (PDUs) and / or one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, suggestions, methods and / or flowcharts disclosed herein. The one or more processors 102, 202 may generate messages, control information, data or information according to the descriptions, functions, procedures, suggestions, methods and / or flowcharts disclosed herein. The one or more processors 102, 202 may generate and provide signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, suggestions and / or methods disclosed herein to the one or more transceivers 106, 206. The one or more processors 102, 202 may receive signals (e.g., baseband signals) from the one or more transceivers 106, 206 and derive the PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, suggestions, methods and / or flowcharts disclosed herein.

[0217] The one or more processors 102, 202 may also be referred to as controllers, microcontrollers, microprocessors, or microcomputers. The one or more processors 102, 202 may be implemented using hardware, firmware, software, or a combination thereof. As an example, the one or more processors 102, 202 may include one or more application specific integrated circuits (ASICs), one or more digital signal processors (DSPs), one or more digital signal processing devices (DSPDs), one or more programmable logic devices (PLDs), or one or more field programmable gate arrays (FPGAs). The descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, and the like. The firmware or software configured to perform the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein may be included in the one or more processors 102, 202, or may be stored in one or more memories 104, 204 and run by the one or more processors 102, 202. The descriptions, functions, procedures, suggestions, methods and / or flow charts disclosed in this specification may be embodied using firmware or software in the form of code, instructions and / or sets of instructions.

[0218] The one or more memories 104, 204 may be coupled to the one or more processors 102, 202 and may store various forms of data, signals, messages, information, programs, code, instructions, and / or commands. The one or more memories 104, 204 may be comprised of ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer readable storage media, and / or combinations thereof. The one or more memories 104, 204 may be located internal and / or external to the one or more processors 102, 202. Additionally, the one or more memories 104, 204 may be coupled to the one or more processors 102, 202 via various techniques, such as wired or wireless connections.

[0219] One or more transceivers 106, 206 may transmit user data, control information, wireless signals / channels, etc., as described in the methods and / or flow charts, etc., herein to one or more other devices. One or more transceivers 106, 206 may receive user data, control information, wireless signals / channels, etc., as described in the descriptions, functions, procedures, suggestions, methods and / or flow charts, etc., disclosed herein from one or more other devices. For example, one or more transceivers 106, 206 may be coupled to one or more processors 102, 202 and may transmit and receive wireless signals. For example, one or more processors 102, 202 may control one or more transceivers 106, 206 to transmit user data, control information, or wireless signals to one or more other devices. Also, one or more processors 102, 202 may control one or more transceivers 106, 206 to receive user data, control information, or wireless signals from one or more other devices. Furthermore, the one or more transceivers 106, 206 are coupled to one or more antennas 108, 208, and the one or more transceivers 106, 206 are configured to transmit and receive user data, control information, radio signals / channels, etc., as referred to in the descriptions, functions, procedures, suggestions, methods and / or flow charts disclosed herein, via the one or more antennas 108, 208. In this specification, the one or more antennas are multiple physical antennas or multiple logical antennas (e.g., antenna ports). The one or more transceivers 106, 206 convert the received user data, control information, radio signals / channels, etc., from RF band signals to baseband signals for processing using the one or more processors 102, 202. The one or more transceivers 106, 206 convert the user data, control information, radio signals / channels, etc., processed using the one or more processors 102, 202, from baseband signals to RF band signals. For this purpose, the one or more transceivers 106, 206 include (analog) oscillators and / or filters.

[0220] 17 shows another example of a wireless device to which the present invention is applied. The wireless device may be embodied in various forms depending on the use case / service (see FIG. 15).

[0221] Referring to Fig. 17, the wireless devices 100 and 200 correspond to the wireless devices 100 and 200 of Fig. 16 and are composed of various elements, components, units / parts and / or modules. For example, the wireless devices 100 and 200 include a communication unit 110, a control unit 120, a memory unit 130 and an additional element 140. The communication unit includes a communication circuit 112 and a transceiver 114. For example, the communication circuit 112 includes one or more processors 102 and 202 and / or one or more memories 104 and 204 in Fig. 16. For example, the transceiver 114 includes one or more transceivers 106 and 206 and / or one or more antennas 108 and 208 in Fig. 16. The control unit 120 is electrically connected to the communication unit 110, the memory unit 130 and the additional element 140 and controls the overall operation of the wireless device. For example, the control unit 120 controls electrical / mechanical operations of the wireless device based on the programs / codes / commands / information stored in the memory unit 130. In addition, the control unit 120 transmits information stored in the memory unit 130 to the outside (e.g., another communication device) via the communication unit 110 through a wireless / wired interface, or stores information received from the outside (e.g., another communication device) via the communication unit 110 through a wireless / wired interface in the memory unit 130.

[0222] The additional element 140 may be configured in various ways depending on the type of wireless device. For example, the additional element 140 may include any one of a power unit / battery, an input / output unit (I / O unit), a driving unit, and a computer unit. The wireless device may be embodied in the form of, but not limited to, a robot (FIG. 15, 100a), a vehicle (FIG. 15, 100b-1, 100b-2), an XR device (FIG. 15, 100c), a mobile device (FIG. 15, 100d), a home appliance (FIG. 15, 100e), an IoT device (FIG. 15, 100f), a digital broadcasting terminal, a hologram device, a public safety device, an MTC device, a medical device, a Fintech device (or a financial device), a security device, a climate / environment device, an AI server / device (FIG. 15, 400), a base station (FIG. 15, 200), and a network node. The wireless device may be mobile or fixed depending on the use case / service.

[0223] In FIG. 17, the various elements, components, units / sections and / or modules within the wireless devices 100, 200 are all coupled to each other by wired interfaces or at least some are wirelessly coupled to each other by a communication unit 110. For example, in the wireless devices 100 and 200, the control unit 120 and the communication unit 110 are connected by wire, and the control unit 120 and a first unit (e.g., 130, 140) are connected wirelessly via the communication unit 110. In addition, each element, component, unit / part and / or module in the wireless devices 100 and 200 further includes one or more elements. For example, the control unit 120 is composed of a set of one or more processors. For example, the control unit 120 is composed of a set of a communication control processor, an application processor, an ECU (Electronic control Unit), a graphics processor, a memory control processor, etc. As another example, the memory unit 130 is composed of a Random Access Memory (RAM), a Dynamic RAM (DRAM), a Read Only Memory (ROM), a flash memory, a volatile memory, a non-volatile memory and / or a combination thereof.

[0224] 18 is a diagram illustrating a vehicle or an autonomous vehicle to which the present invention is applied. The vehicle or the autonomous vehicle may be realized as a mobile robot, a car, a train, an aerial vehicle (AV), a ship, or the like.

[0225] 18, a vehicle or autonomous vehicle 100 includes an antenna unit 108, a communication unit 110, a control unit 120, a drive unit 140a, a power supply unit 140b, a sensor unit 140c, and an autonomous driving unit 140d. The antenna unit 108 is configured as a part of the communication unit 110. Blocks 110 / 130 / 140a to 140d correspond to blocks 110 / 130 / 140 in FIG. 17, respectively.

[0226] The communication unit 110 transmits and receives signals (e.g., data, control signals, etc.) to and from external devices such as other vehicles, base stations (e.g., base stations, road side units, etc.), and servers. The control unit 120 controls elements of the vehicle or autonomous vehicle 100 to perform various operations. The control unit 120 includes an ECU (Electronic Control Unit). The driving unit 140a causes the vehicle or autonomous vehicle 100 to run on the ground. The driving unit 140a includes an engine, a motor, a power train, wheels, brakes, a steering device, etc. The power supply unit 140b supplies power to the vehicle or autonomous vehicle 100 and includes wired / wireless charging circuits, a battery, etc. The sensor unit 140c can obtain vehicle status, surrounding environment information, user information, etc. The sensor unit 140c includes an IMU (inertial measurement unit) sensor, a collision sensor, a wheel sensor, a speed sensor, a tilt sensor, a weight sensor, a heading sensor, a position module, a vehicle forward / reverse sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, an illuminance sensor, a pedal position sensor, etc. The autonomous driving unit 140d embodies a technology for maintaining a lane while driving, a technology for automatically adjusting speed such as an adaptive cruise control, a technology for automatically driving according to a predetermined route, a technology for automatically setting a route when a destination is set, and the like.

[0227] For example, the communication unit 110 receives map data, traffic information data, etc. from an external server. The autonomous driving unit 140d generates an autonomous driving route and a drive plan based on the obtained data. The control unit 120 controls the driving unit 140a (e.g., speed / direction adjustment) so that the vehicle or autonomous driving vehicle 100 moves along the autonomous driving route according to the drive plan. The communication unit 110 non-periodically obtains the latest traffic information data from an external server during autonomous driving, and also obtains surrounding traffic information data from surrounding vehicles. In addition, the sensor unit 140c obtains vehicle status and surrounding environment information during autonomous driving. The autonomous driving unit 140d updates the autonomous driving route and the drive plan based on the newly obtained data / information. The communication unit 110 transmits information regarding the vehicle position, the autonomous driving route, the drive plan, etc. to the external server. The external server can predict traffic information data in advance using AI technology, etc. based on information collected from the vehicle or autonomous driving vehicle, and provide the predicted traffic information data to the vehicle or autonomous driving vehicle.

[0228] FIG. 19 is a diagram for explaining a DRX (Discontinuous Reception) operation of a terminal according to one embodiment of the present invention.

[0229] A terminal can perform DRX operation while executing the procedures and / or methods described / proposed above. A terminal configured for DRX can reduce power consumption by discontinuously receiving DL signals. DRX is performed in RRC (Radio Resource Control)_IDLE state, RRC_INACTIVE state, and RRC_CONNECTED state. DRX in the RRC_IDLE state and RRC_INACTIVE state is used to discontinuously receive paging signals. DRX performed in the RRC_CONNECTED state will be described below (RRC_CONNECTED DRX).

[0230] Referring to FIG. 19, the DRX cycle consists of On Duration and Opportunity for DRX. The DRX cycle defines a time interval in which On Duration is repeated periodically. On Duration indicates a time period in which the terminal monitors to receive the PDCCH. When DRX is configured, the terminal performs PDCCH monitoring during On Duration. If there is a successfully detected PDCCH during PDCCH monitoring, the terminal operates an inactivity timer and maintains an awake state. On the other hand, if there is no successfully detected PDCCH during PDCCH monitoring, the terminal enters a sleep state after the On Duration ends. Thus, when DRX is configured, PDCCH monitoring / reception is performed discontinuously in the time domain when performing the above-described / proposed procedure and / or method. For example, when DRX is configured, in this specification, PDCCH reception opportunities (e.g., slots having a PDCCH search space) are set discontinuously according to the DRX configuration. On the other hand, when DRX is not configured, PDCCH monitoring / reception is performed continuously in the time domain when performing the above / proposed procedures and / or methods. For example, in this specification, PDCCH reception opportunities (e.g., slots having PDCCH search space) are configured continuously when DRX is not configured. On the other hand, PDCCH monitoring may be restricted in the time period configured in the measurement gap regardless of whether DRX is configured or not.

[0231] Table 7 shows the process of the terminal related to DRX (RRC_CONNECTED state). Referring to Table 7, DRX configuration information is received via higher layer (e.g., RRC) signaling, and DRX ON / OFF is controlled by a DRX command of the MAC layer. If DRX is configured, the terminal can perform PDCCH monitoring discontinuously when performing the procedures and / or methods described / proposed in the present invention.

[0232] [Table 7]

[0233] Here, MAC-CellGroupConfig includes configuration information required to set MAC (Medium Access Control) parameters for a cell group. MAC-CellGroupConfig may include configuration information related to DRX. For example, MAC-CellGroupConfig includes the following information in the definition of DRX:

[0234] - Value of drx-OnDurationTimer: defines the length of the start period of the DRX cycle

[0235] - Value of drx-InactivityTimer: defines the length of the time interval in which the terminal is in an awake state after a PDCCH opportunity in which a PDCCH indicating early UL or DL ​​data is detected.

[0236] - Value of drx-HARQ-RTT-TimerDL: defines the length of the maximum time interval after a DL initial transmission is received until a DL retransmission is received.

[0237] - Value of drx-HARQ-RTT-TimerDL: Defines the maximum time interval between when a grant for a UL initial transmission is received and when a grant for a UL retransmission is received.

[0238] - drx-LongCycleStartOffset: defines the length and start time of a DRX cycle

[0239] - drx-ShortCycle(optional): defines the time length of a short DRX cycle

[0240] Here, if any one of the drx-OnDurationTimer, drx-InactivityTimer, drx-HARQ-RTT-TimerDL, and drx-HARQ-RTT-TimerDL is operating, the terminal maintains an active state and performs PDCCH monitoring at every PDCCH opportunity.

[0241] The above-described embodiments are combinations of the components and features of the present invention in a predetermined form. Each component or feature should be considered as optional unless otherwise expressly stated. Each component or feature may be implemented in a form not combined with other components or features. Also, some components and / or features may be combined to form an embodiment of the present invention. The order of each operation described in the embodiments of the present invention may be changed. Some configurations or features of any embodiment may be included in other embodiments, or may be replaced with corresponding configurations or features of other embodiments. It is obvious that claims that are not explicitly cited in the claims may be combined to form an embodiment, or may be included as a new claim by amendment after filing.

[0242] It is obvious to those skilled in the art that the present invention can be embodied in other specific forms without departing from the characteristics of the present invention. Therefore, the above detailed description should not be interpreted as limiting in all respects, but should be considered as illustrative. The scope of the present invention should be determined by reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present invention are included in the scope of the present invention. [Industrial Applicability]

[0243] The present invention can be used in a terminal, a base station or other equipment of a wireless mobile communication system.

Claims

1. A method for a terminal (UE) receiving a signal in a wireless communication system, comprising: Receive DCI (downlink control information) via PDCCH (physical downlink control channel); receiving at least one transport block (TB) via a physical downlink shared channel (PDSCH) in at least one of a plurality of cells configured for the terminal based on the DCI; and transmitting hybrid automatic repeat request-acknowledgement (HARQ-ACK) information for the at least one TB; The DCI supports multi-cell scheduling based on the plurality of cells; The number of ACK / NACK (acknowledgement / negative-acknowledgement) bits included in the HARQ-ACK information is determined based on at least one of a maximum number of cells that can be co-scheduled by the DCI or a maximum number of TBs that can be received via cells co-scheduled by the DCI.

2. Based on the fact that the maximum number of TBs per PDSCH is 2 and spatial bundling is not configured in at least one cell among the cells that can be scheduled together by the DCI, The method of claim 1, wherein the number of ACK / NACK bits included in the HARQ-ACK information is determined based on a maximum number of TBs that can be received via cells that are co-scheduled by the DCI.

3. In each of the cells that can be scheduled together by the DCI, the maximum number of TBs per PDSCH is 1 or spatial bundling is configured, The method of claim 1, wherein the number of ACK / NACK bits included in the HARQ-ACK information is determined based on a maximum number of cells that can be co-scheduled by the DCI.

4. The method of claim 1 , wherein the maximum number of cells that can be co-scheduled by the DCI is related to a cell combination that includes the most cells among cell combinations that can be co-scheduled by the DCI.

5. The method of claim 1 , wherein within the HARQ-ACK information, the ACK / NACK bits are aligned based on serving cell indexes of co-scheduled cells.

6. The DCI includes information regarding a downlink assignment index (DAI), The method of claim 1 , wherein the DAI is determined based on a cell having a smallest serving cell index among cells co-scheduled by the DCI.

7. HARQ-ACK information for single-cell scheduling is included in the first sub-codebook; The method of claim 1 , wherein the HARQ-ACK information regarding the multi-cell scheduling is included in a second sub-codebook.

8. The method of claim 7, wherein one HARQ-ACK codebook is constructed based on a concatenation of the first sub-codebook and the second sub-codebook.

9. The first sub-codebook is associated with a PDSCH scheduled by a multi-cell scheduling DCI and a single-cell scheduling DCI in which one cell is actually scheduled; The method of claim 7, wherein the second sub-codebook is associated with a PDSCH scheduled by a multi-cell scheduling DCI in which two or more cells are actually scheduled.

10. A computer-readable recording medium having a program recorded thereon for carrying out the method according to claim 1.

11. A device for wireless communication, comprising: A memory for storing instruction words; and A processor that operates by executing the instruction code, The operation of the processor includes: Receive downlink control information (DCI) via a physical downlink control channel (PDCCH); receiving at least one transport block (TB) via a physical downlink shared channel (PDSCH) in at least one of a plurality of cells configured for the device based on the DCI; and transmitting hybrid automatic repeat request-acknowledgement (HARQ-ACK) information for the at least one TB; The DCI supports multi-cell scheduling based on the plurality of cells; The number of ACK / NACK (acknowledgement / negative-acknowledgement) bits included in the HARQ-ACK information is determined based on at least one of a maximum number of cells that can be co-scheduled by the DCI or a maximum number of TBs that can be received via cells co-scheduled by the DCI.

12. a transceiver for transmitting or receiving wireless signals under the control of said processor; The device of claim 11, wherein the device is a terminal (UE) in a wireless communication system.

13. The device according to claim 11, wherein the device is an application specific integrated circuit (ASIC) or a digital signal processing device for controlling a terminal (UE).

14. 1. A method for a base station to transmit a signal in a wireless communication system, comprising: Transmit DCI (downlink control information) to the terminal via PDCCH (physical downlink control channel); Transmitting at least one transport block (TB) via a physical downlink shared channel (PDSCH) in at least one of a plurality of cells configured for the terminal based on the DCI; and receiving hybrid automatic repeat request-acknowledgement (HARQ-ACK) information for the at least one TB; The DCI supports multi-cell scheduling based on the plurality of cells; The number of ACK / NACK (acknowledgement / negative-acknowledgement) bits included in the HARQ-ACK information is determined based on at least one of a maximum number of cells that can be co-scheduled by the DCI or a maximum number of TBs that can be transmitted via cells co-scheduled by the DCI.

15. A base station for transmitting a signal in a wireless communication system, comprising: A transceiver, and A processor controls the transceiver to transmit downlink control information (DCI) to a terminal via a physical downlink control channel (PDCCH), transmit at least one transport block (TB) via a physical downlink shared channel (PDSCH) in at least one of a plurality of cells configured in the terminal based on the DCI, and receive hybrid automatic repeat request-acknowledgement (HARQ-ACK) information for the at least one TB; The DCI supports multi-cell scheduling based on the plurality of cells; A base station, wherein the number of ACK / NACK (acknowledgement / negative-acknowledgement) bits included in the HARQ-ACK information is determined based on at least one of the maximum number of cells that can be co-scheduled by the DCI or the maximum number of TBs that can be transmitted via cells co-scheduled by the DCI.

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