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

Abstract

A method and apparatus for efficiently performing a process of transmitting and receiving a radio signal are provided. [Solution] The present invention relates to a wireless communication system, and more specifically, to a method and apparatus therefor, including a step of decoding multiple CBGs that constitute a TB, a step of re-receiving the TB after decoding, and a step of transmitting multiple HARQ-ACK bits for the re-reception of the TB, each HARQ-ACK bit indicating a HARQ-ACK response for each CBG of the TB, wherein among the multiple HARQ-ACK bits, the HARQ-ACK bit for a first CBG that was successfully decoded before the re-reception of the TB is mapped to an ACK when the TB is re-received, regardless of whether the first CBG is received or not.

Description

[Technical field]

[0001] The present invention relates to a wireless communication system, and more particularly to a method and apparatus for transmitting and receiving a wireless signal.The wireless communication system includes a wireless communication system based on Carrier Aggregation (CA). [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, and single carrier frequency division multiple access (SC-FDMA) systems. Summary of the Invention [Problem to be solved by the invention]

[0003] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a method and apparatus for efficiently performing a process of transmitting and receiving a radio signal.

[0004] The technical problem to be achieved by the present invention is not limited to the above technical problem, 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] In one aspect of the present invention, a method for a terminal to transmit control information in a wireless communication system includes the steps of receiving information regarding a number M of code block groups defined for one transport block from a base station through an upper layer signal, receiving a first transport block including a plurality of code blocks from the base station through a physical layer channel, and transmitting a HARQ-ACK payload including hybrid ARQ Acknowledgement (HARQ-ACK) information regarding the first transport block to the base station, wherein a code block-based CRC (Cyclic Redundancy Check) is added to each code block, a transport block-based CRC is added to the first transport block, and the HARQ-ACK payload includes a plurality of HARQ-ACK bits corresponding to the M code block groups for the first transport block.

[0006] In another aspect of the present invention, there is provided a terminal for use in a wireless communication system, the terminal including: a Radio Frequency (RF) module; and a processor, the processor being configured to receive, from a base station, information regarding a number M of code block groups defined for one transmission block through an upper layer signal; receive a first transmission block including a plurality of code blocks from the base station through a physical layer channel; and transmit, to the base station, a HARQ-ACK payload including hybrid ARQ Acknowledgement (HARQ-ACK) information regarding the first transmission block, wherein a code block-based Cyclic Redundancy Check (CRC) is added to each code block, a transmission block-based CRC is added to the first transmission block, and the HARQ-ACK payload includes a plurality of HARQ-ACK bits corresponding to the M code block groups for the first transmission block.

[0007] Preferably, the higher layer signal includes a Radio Resource Control (RRC) signal, and the physical layer channel includes a Physical Downlink Shared Channel (PDSCH).

[0008] Preferably, the size of the HARQ-ACK payload is kept the same based on M during the HARQ process for the first transport block.

[0009] Preferably, when the first transmission block is composed of a plurality of code block groups, some of the plurality of code block groups include ceiling(K / M) code blocks, and the remaining of the plurality of code block groups include flooring(K / M) code blocks, where ceiling is a round-up function, flooring is a round-down function, and K is the number of code blocks in the first transmission block.

[0010] Preferably, when a code block group is set for the first transport block, each HARQ-ACK bit in the HARQ-ACK payload indicates each HARQ-ACK information generated on a code block group basis for the first transport block.

[0011] Preferably, when a code block group is not set for the first transport block, the multiple HARQ-ACK bits for the first transport block in the HARQ-ACK payload all have the same value, and each HARQ-ACK bit for the first transport block indicates HARQ-ACK information generated on a transport block group basis for the first transport block.

[0012] Preferably, if the code block group-based CRC check results for the first transport block are all successful, but the transport block-based CRC check results are unsuccessful, then all of the HARQ-ACK bits for the first transport block in the HARQ-ACK payload indicate a NACK (Negative Acknowledgement).

[0013] In yet another aspect of the present invention, there is provided a method for a base station receiving control information in a wireless communication system, the method including the steps of: transmitting information regarding a number M of code block groups defined for one transport block to a terminal through an upper layer signal; transmitting a first transport block including a plurality of code blocks to the terminal through a physical layer channel; and receiving a HARQ-ACK payload from the terminal including hybrid ARQ Acknowledgement (HARQ-ACK) information regarding the first transport block, wherein a code block-based CRC (Cyclic Redundancy Check) is added to each code block, a transport block-based CRC is added to the first transport block, and the HARQ-ACK payload includes a plurality of HARQ-ACK bits corresponding to the M code block groups for the first transport block.

[0014] In yet another aspect of the present invention, there is provided a base station for use in a wireless communication system, the base station including a radio frequency (RF) module and a processor, the processor being configured to transmit information regarding a number M of code block groups defined for one transmission block to a terminal through an upper layer signal, transmit a first transmission block including a plurality of code blocks to the terminal through a physical layer channel, and receive from the terminal a HARQ-ACK payload including hybrid ARQ Acknowledgement (HARQ-ACK) information regarding the first transmission block, wherein a code block-based cyclic redundancy check (CRC) is added to each code block, a transmission block-based CRC is added to the first transmission block, and the HARQ-ACK payload includes a plurality of HARQ-ACK bits corresponding to the M code block groups for the first transmission block. Effect of the Invention

[0015] According to the present invention, it is possible to efficiently transmit and receive radio signals in a radio communication system.

[0016] 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]

[0017] The accompanying drawings, which are included as part of the detailed description to aid in understanding the present invention, provide examples of the present invention and, together with the detailed description, explain the technical concepts of the present invention.

[0018] [Figure 1] 1 is a diagram illustrating physical channels used in a 3GPP LTE(-A) 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 a downlink slot. [Figure 4] A diagram showing the structure of a downlink subframe. [Diagram 5] FIG. 1 is a diagram illustrating an Enhanced Physical Downlink Control CHannel (EPDCCH). [Figure 6] A diagram illustrating the structure of an uplink subframe used in LTE(-A). [Figure 7] FIG. 1 is a diagram illustrating a Single Carrier Frequency Division Multiple Access (SC-FDMA) system and an Orthogonal Frequency Division Multiple Access (OFDMA) system. [Figure 8] FIG. 1 illustrates an example of UL HARQ (Uplink Hybrid Automatic Repeat reQuest) operation. [Figure 9] FIG. 1 is a diagram illustrating a process of processing a transport block (TB). [Figure 10]FIG. 13 is a diagram illustrating a random connection process. [Figure 11] FIG. 13 is a diagram illustrating a random connection process. [Figure 12] FIG. 1 illustrates a Carrier Aggregation (CA) communication system. [Figure 13] FIG. 1 illustrates an example of cross-carrier scheduling. [Figure 14] FIG. 1 illustrates analog beamforming. [Figure 15] FIG. 1 illustrates a self-contained subframe structure. [Figure 16] FIG. 2 illustrates a signal transmission according to the present invention. [Figure 17] FIG. 2 illustrates a signal transmission according to the present invention. [Figure 18] FIG. 2 is a diagram illustrating a base station and a terminal applicable to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The following technologies can be used in various wireless access systems such as code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), and single carrier frequency division multiple access (SC-FDMA). CDMA can be implemented by radio technologies such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA can be implemented by radio technologies such as Global System for Mobile communications (GSM), General Packet Radio Service (GPRS), and 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, and Evolved UTRA (E-UTRA). UTRA is part of the Universal Mobile Telecommunications System (UMTS). 3GPP (3rd Generation Partnership Project) LTE (long term evolution) is a part of E-UMTS (Evolved UMTS) using E-UTRA, and adopts OFDMA in the downlink and SC-FDMA in the uplink. LTE-A (Advanced) is an evolved version of 3GPP LTE. For clarity of explanation, 3GPP LTE / LTE-A has been mainly described, but the technical idea of ​​the present invention is not limited thereto.

[0020] 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 exchanged 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 exchanged.

[0021] FIG. 1 is a diagram illustrating physical channels used in a 3GPP LTE(-A) system and a general signal transmission method using these channels.

[0022] A terminal that has been turned on in a power-off state or that has newly entered a cell performs an initial cell search such as establishing synchronization with a base station in step S101. To this end, the terminal receives a Primary Synchronization Channel (P-SCH) and a Secondary Synchronization Channel (S-SCH) from the base station to establish synchronization with the base station and obtain information such as a cell identity. Then, the terminal receives a Physical Broadcast Channel (PBCH) from the base station to obtain broadcast information within the cell. In addition, the terminal can receive a Downlink Reference Signal (DL RS) in the initial cell search stage to check the state of the downlink channel.

[0023] 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.

[0024] 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 over a physical random access channel (PRACH) (S103) and receives a response message to the preamble over 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).

[0025] 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 of the network.

[0026] Figure 2 illustrates a radio frame structure. Uplink / downlink data packet transmission is made up of subframe units, and one subframe is defined as a certain time period including multiple OFDM symbols. LTE(-A) supports a type 1 radio frame structure for FDD (Frequency Division Duplex) and a type 2 radio frame structure for TDD (Time Division Duplex).

[0027] FIG. 2(a) illustrates a type 1 radio frame structure. A downlink radio frame is composed of 10 subframes, and each subframe is composed of two slots in the time domain. The time it takes to transmit one subframe is called a transmission time interval (TTI). For example, the length of one subframe may be 1 ms, and the length of one slot may be 0.5 ms. One slot includes multiple OFDM symbols in the time domain and multiple resource blocks (RBs) in the frequency domain. In the 3GPP LTE(-A) system, since OFDMA is used in the downlink, an OFDM symbol indicates one symbol interval. An OFDM symbol can also be called an SC-FDMA symbol or symbol interval. A resource block (RB), as a resource allocation unit, can include multiple consecutive subcarriers in one slot.

[0028] The number of OFDM symbols contained in a slot varies depending on the CP (Cyclic Prefix) configuration. There are extended CP and normal CP. For example, when an OFDM symbol is configured with a normal CP, the number of OFDM symbols contained in one slot is seven. When an OFDM symbol is configured with an extended CP, the length of one OFDM symbol is longer, so the number of OFDM symbols contained in one slot is less than in the case of a normal CP. For example, in the case of an extended CP, the number of OFDM symbols contained in one slot is six. When the channel condition is unstable due to high-speed movement of a terminal, etc., an extended CP is used to reduce interference between symbols.

[0029] When normal CP is used, a slot contains 7 OFDM symbols, so a subframe contains 14 OFDM symbols. Up to 3 OFDM symbols from the beginning of a subframe are assigned to the physical downlink control channel (PDCCH) and the other OFDM symbols are assigned to the physical downlink shared channel (PDSCH).

[0030] Figure 2(b) illustrates the structure of a type 2 radio frame. A type 2 radio frame is composed of two half frames. A half frame includes four (5) general subframes and one (0) special subframe. The general subframes are used for uplink or downlink depending on the uplink-downlink configuration (UL-DL configuration). A subframe is composed of two slots.

[0031] Table 1 illustrates an example of a subframe configuration within a radio frame according to the UL-DL configuration.

[0032] [Table 1]

[0033] In the table, D indicates a downlink subframe, U indicates an uplink subframe, and S indicates a special subframe. A special subframe includes a Downlink Pilot Time Slot (DwPTS), a Guard Period (GP), and an Uplink Pilot Time Slot (UpPTS). The DwPTS is used for initial cell search, synchronization, and channel estimation in the terminal. The UpPTS is used for channel estimation in the base station and for establishing uplink transmission synchronization in the terminal. The guard interval is an interval for removing interference that may occur in the uplink due to multipath delay of the downlink signal between the uplink and downlink.

[0034] The radio frame structure is merely an example, and the number of subframes, the number of slots, and the number of symbols in the radio frame can be changed in various ways.

[0035] FIG. 3 is a diagram illustrating a resource grid of a downlink slot.

[0036] Referring to FIG. 3, a downlink slot includes a number of OFDM symbols in the time domain. Here, it is illustrated that one downlink slot includes seven OFDM symbols and one resource block (RB) includes 12 subcarriers in the frequency domain. However, the present invention is not limited thereto. Each element on the resource grid is called a resource element (RE). One RB includes 12×7 RE. The number of RBs included in a downlink slot (NDL) depends on the downlink transmission bandwidth. The structure of an uplink slot is the same as that of a downlink slot.

[0037] FIG. 4 illustrates a downlink subframe structure.

[0038] Referring to FIG. 4, up to three (4) OFDM symbols located at the front of the first slot of a subframe correspond to a control region to which a control channel is assigned. The other OFDM symbols correspond to a data region to which a PDSCH (physical downlink shared chancel) is assigned, and the basic resource unit of the data region is RB. Examples of downlink control channels used in LTE include PCFICH (physical control format indicator channel), PDCCH (physical downlink control channel), PHICH (physical hybrid ARQ indicator channel), etc. PCFICH is transmitted in the first OFDM symbol of a subframe and carries information on the number of OFDM symbols used for transmitting a control channel in the subframe. PHICH is a response to uplink transmission and carries a HARQ ACK / NACK (hybrid automatic repeat request acknowledgment / negative-acknowledgment) signal. Control information transmitted via PDCCH is called DCI (downlink control information). The DCI includes uplink or downlink scheduling information or an uplink transmit power control command for a given terminal group.

[0039] Control information transmitted through the PDCCH is called DCI (Downlink Control Information). DCI formats are defined as formats 0, 3, 3A, and 4 for uplink, and formats 1, 1A, 1B, 1C, 1D, 2, 2A, 2B, and 2C for downlink. The type of information field, the number of information fields, and the number of bits of each information field vary depending on the DCI format. For example, the DCI format selectively includes information such as a hopping flag, RB allocation, MCS (Modulation Coding Scheme), RV (Redundancy Version), NDI (New Data Indicator), TPC (Transmit Power Control), cyclic shift for DMRS (DeModulation Reference Signal), CQI (Channel Quality Information) request, HARQ process number, TPMI (Transmitted Precoding Matrix Indicator), and PMI (Precoding Matrix Indicator) depending on the purpose. Therefore, the size of the control information that is matched to the DCI format varies depending on the DCI format. Note that any DCI format is used for transmitting two or more types of control information. For example, DCI format 0 / 1A is used to carry DCI format 0 or DCI format 1, which are distinguished by a flag field.

[0040] The PDCCH carries the transmission format and resource allocation of the downlink shared channel (DL-SCH), resource allocation information for the uplink shared channel (UL-SCH), paging information for the paging channel (PCH), system information on the DL-SCH, resource allocation information of higher layer control messages such as random access responses transmitted on the PDSCH, transmission power control commands for individual terminals in a given terminal group, activation of Voice over IP (VoIP), etc. Multiple PDCCHs can be transmitted in a control domain. A terminal can monitor multiple PDCCHs. The PDCCH is transmitted on an aggregation of one or multiple consecutive control channel elements (CCEs). A CCE is a logical allocation unit used to provide a coding rate for the PDCCH based on radio channel conditions. A CCE corresponds to multiple resource element groups (REGs). The format of the PDCCH and the number of PDCCH bits are determined by the number of CCEs. The base station determines the PDCCH format according to the DCI transmitted to the terminal, and adds a Cyclic Redundancy Check (CRC) to the control information. The CRC is masked with an identifier (e.g., a Radio Network Temporary Identifier (RNTI)) depending on the owner or purpose of the PDCCH. For example, if the PDCCH is for a specific terminal, the identifier of the terminal (e.g., a Cell-RNTI (C-RNTI)) may be masked with the CRC. If the PDCCH is for a paging message, a paging identifier (e.g., a Paging-RNTI (P-RNTI)) is masked with the CRC. If the PDCCH is for system information (more specifically, a System Information Block (SIB)), a System Information RNTI (SI-RNTI) is masked with the CRC.If the PDCCH is for a random access response, the Random Access-RNTI (RA-RNTI) is masked with a CRC.

[0041] The PDCCH carries a message known as downlink control information (DCI), which includes resource allocation and other control information for a terminal or a group of terminals. Typically, multiple PDCCHs are transmitted in one subframe. Each PDCCH is transmitted using one or more control channel elements (CCEs), each CCE corresponding to nine sets of four resource elements. The four resource elements are referred to as a resource element group (REG). Four QPSK symbols are mapped to one REG. Resource elements assigned to reference signals are not included in the REG, so that the total number of REGs in a given OFDM symbol depends on the presence or absence of cell-specific reference signals. The REG concept (i.e., group-based mapping, each group containing four resource elements) is also used for other downlink control channels (PCFICH and PHICH). That is, the REG is used as the basic resource unit of the control region. Four PDCCH formats are supported as shown in Table 2.

[0042] [Table 2]

[0043] The CCEs are used consecutively numbered, and in order to simplify the decoding process, a PDCCH having a format with n CCEs starts only with CCEs having the same number as a multiple of n. The number of CCEs used for transmission of a given PDCCH is determined by the base station according to the channel conditions. For example, if the PDCCH is for a terminal having a good downlink channel (e.g., close to the base station), one CCE is sufficient. However, for a terminal having a bad channel (e.g., close to the cell boundary), eight CCEs are used to obtain sufficient robustness. Also, the power level of the PDCCH can be adjusted to the channel conditions.

[0044] The approach introduced in LTE is to define the CCE positions in a restricted set where the PDCCH can be located for each terminal. The positions of the CCEs in the restricted set where the terminal can search for its PDCCH are called search space (SS). In LTE, the search space has a different size for each PDCCH format. In addition, UE-specific and common search spaces are defined separately. The UE-specific search space (USS) is set individually for each terminal, and the range of the common search space (CSS) is notified to all terminals. The UE-specific and common search spaces can overlap for a given terminal. When the search space is very small, if some CCE positions are assigned in the search space for a given terminal, there are no remaining CCEs, so the base station cannot find CCE resources to transmit PDCCH to all terminals as much as possible in a given subframe. In this way, in order to minimize the possibility that blocking continues to the next subframe, a terminal-specific hopping sequence is applied to the start position of the UE-specific search space.

[0045] Table 3 shows the size of the common and UE-specific search spaces.

[0046] [Table 3]

[0047] In order to keep the computation load due to the total number of blind decoding (BD) operations under control, the terminal is not required to simultaneously search all defined DCI formats. In general, in a UE-specific search space, the terminal always searches formats 0 and 1A. Formats 0 and 1A have the same size and are distinguished by a flag in a message. The terminal may also be requested to receive additional formats (e.g., 1, 1B, or 2 depending on the PDSCH transmission mode set by the base station). In a common search space, the terminal searches formats 1A and 1C. The terminal may also be configured to search formats 3 or 3A. Formats 3 and 3A have the same size as formats 0 and 1A and are distinguished by scrambling the CRC with a different (common) identifier rather than a terminal-specific identifier. The following describes the PDSCH transmission technique according to the transmission mode and the information content of the DCI format.

[0048] Transmission Mode (TM)

[0049] ● Transmission mode 1: Transmission from a single base station antenna port

[0050] ● Transmission mode 2: Transmission diversity

[0051] ● Transmission mode 3: Open-loop spatial multiplexing

[0052] ● Transmission mode 4: Closed-loop spatial multiplexing

[0053] ● Transmission mode 5: Multi-user MIMO

[0054] ● Transmission mode 6: Closed-loop rank-1 precoding

[0055] ● Transmission mode 7: Transmission through a single antenna port (port 5)

[0056] ● Transmission mode 8: dual-layer transmission (ports 7 and 8) or single-antenna port (port 7 or 8) transmission

[0057] ● Transmission mode 9: Up to eight layer transmission (ports 7 to 14) or single-antenna port transmission (ports 7 or 8)

[0058] DCI Format

[0059] ● Format 0: Resource grant for PUSCH transmission (uplink)

[0060] Format 1: Resource allocation for single codeword PDSCH transmission (transmission modes 1, 2 and 7)

[0061] Format 1A: Compact signalling of resource allocation for single codeword PDSCH (all modes)

[0062] Format 1B: Compact resource allocation for PDSCH (mode 6) with rank-1 closed-loop precoding

[0063] ● Format 1C: Very compact resource allocation for PDSCH (e.g. paging / broadcasting system information)

[0064] ● Format 1D: Compact resource allocation for PDSCH (mode 5) with multi-user MIMO

[0065] Format 2: Resource allocation for PDSCH (mode 4) in closed-loop MIMO operation

[0066] Format 2A: Resource allocation for PDSCH (mode 3) in open-loop MIMO operation

[0067] Format 3 / 3A: Power control command with 2-bit / 1-bit power adjustment value for PUCCH and PUSCH

[0068] 5 is a diagram illustrating an EPDCCH, which is a channel further introduced in LTE-A.

[0069] Referring to FIG. 5, a PDCCH (for convenience, Legacy PDCCH, L-PDCCH) according to existing LTE is allocated to the control region (see FIG. 4) of a subframe. In the figure, the L-PDCCH region means a region to which the L-PDCCH is allocated. In addition, a PDCCH can be further allocated in the data region (e.g., a resource region for PDSCH). The PDCCH allocated to the data region is referred to as an EPDCCH. As shown in the figure, by further securing control channel resources through the EPDCCH, scheduling constraints due to limited control channel resources in the L-PDCCH region can be alleviated. Like the L-PDCCH, the EPDCCH carries DCI. For example, the EPDCCH can carry downlink scheduling information and uplink scheduling information. For example, a terminal receives an EPDCCH and receives data / control information through a PDSCH corresponding to the EPDCCH. Also, a terminal receives an EPDCCH and transmits data / control information through a PUSCH corresponding to the EPDCCH. Depending on the cell type, the EPDCCH / PDSCH can be allocated from the first OFDM symbol of a subframe. Unless otherwise specified, in this specification, PDCCH includes both L-PDCCH and EPDCCH.

[0070] FIG. 6 is a diagram illustrating the structure of an uplink subframe used in LTE(-A).

[0071] Referring to FIG. 6, a subframe 500 is composed of two 0.5 ms slots 501. Assuming a normal cyclic prefix (CP) length, each slot is composed of seven symbols 502, and one symbol corresponds to one SC-FDMA symbol. A resource block (RB) 503 is a resource allocation unit corresponding to 12 subcarriers in the frequency domain and one slot in the time domain. The structure of an uplink subframe of LTE(-A) is largely divided into a data region 504 and a control region 505. The data region refers to communication resources used for data transmission such as voice and packets transmitted to each terminal, and includes a PUSCH (Physical Uplink Shared Channel). The control region refers to communication resources used for transmission of uplink control signals, such as downlink channel quality reports from each terminal, reception ACK / NACK for downlink signals, uplink scheduling requests, etc., and includes a PUCCH (Physical Uplink Control Channel). A Sounding Reference Signal (SRS) is transmitted via the SC-FDMA symbol located at the end of the time axis in one subframe. SRSs of multiple terminals transmitted in the last SC-FDMA of the same subframe can be distinguished by frequency position / sequence. SRS is used to transmit uplink channel conditions to the base station and is transmitted periodically according to the subframe period / offset set by the uplink layer (e.g., RRC layer) or aperiodically at the request of the base station.

[0072] 7 is a diagram illustrating the SC-FDMA method and the OFDMA method. In the 3GPP system, OFDMA is adopted in the downlink, and SC-FDMA is adopted in the uplink.

[0073] 7, a terminal for uplink signal transmission and a base station for downlink signal transmission are the same in that they both include a serial-to-parallel converter 401, a subcarrier mapper 403, an M-point IDFT module 404, and a CP (Cyclic Prefix) adding module 406. However, a terminal for transmitting signals using the SC-FDMA scheme further includes an N-point DFT module 402. The N-point DFT module 402 allows a transmission signal to have a single carrier property by partially canceling the IDFT processing effect of the M-point IDFT module 404.

[0074] Next, a description will be given of HARQ (Hybrid Automatic Repeat reQuest). In a wireless communication system, when there are a number of terminals having data to transmit on uplink / downlink, a base station selects a terminal to transmit data for each transmission time interval (TTI) (e.g., subframe). In a multi-carrier or similarly operated system, a base station selects a terminal to transmit data on uplink / downlink for each TTI, and also selects a frequency band to be used by the terminal for data transmission.

[0075] In terms of uplink, a plurality of terminals transmit reference signals (or pilots) via uplink, and the base station grasps the channel state of the terminals using the reference signals transmitted from the terminals and selects terminals to transmit data via uplink in each unit frequency band for each TTI. The base station notifies the terminals of the result. That is, the base station transmits an uplink assignment message to a terminal scheduled for uplink in a specific TTI to transmit data using a specific frequency band. The uplink assignment message is also called a UL grant. The terminal transmits data to the uplink through the uplink assignment message. The uplink assignment message includes a terminal ID (UE Identity), RB assignment information, a Modulation and Coding Scheme (MCS), a Redundancy Version (RV), a new data indication (NDI), and the like.

[0076] In the case of a synchronous HARQ scheme, the retransmission time is guaranteed by the system (e.g., 4 subframes after the reception of NACK) (synchronous HARQ). Therefore, the UL grant message sent by the base station to the terminal only needs to be sent at the initial transmission. Subsequent retransmissions are performed by an ACK / NACK signal (e.g., a PHICH signal). In the case of an asynchronous HARQ scheme, the retransmission time is not mutually guaranteed, so the base station must issue a retransmission request message to the terminal. In addition, in the case of a non-adaptive HARQ scheme, the frequency resources and MCS for retransmission are the same as those in the previous transmission, and in the case of an adaptive HARQ scheme, the frequency resources and MCS for retransmission may be different from those in the previous transmission. As an example, in the case of an asynchronous adaptive HARQ scheme, the frequency resources and MCS for retransmission are different for each transmission time, so the retransmission request message may include the terminal ID, RB allocation information, HARQ process ID / number, RV, and NDI information.

[0077] FIG. 8 is a diagram illustrating an example of UL HARQ operation in the LTE(-A) system. In the LTE(-A) system, the UL HARQ scheme uses synchronous non-adaptive HARQ. When using 8-channel HARQ, the HARQ process numbers are 0 to 7. One HARQ process operates for each TTI (e.g., subframe). Referring to FIG. 8, the base station 110 transmits an UL grant to the terminal 120 via a PDCCH (S600). The terminal 120 transmits uplink data to the base station 110 using the RB and MCS specified by the UL grant four subframes later (e.g., subframe 4) from the time point when the UL grant is received (e.g., subframe 0) (S602). The base station 110 decodes the uplink data received from the terminal 120 and then generates an ACK / NACK. If decoding of the uplink data fails, the base station 110 transmits a NACK to the terminal 120 (S604). The terminal 120 retransmits the uplink data four subframes after receiving the NACK (S606). The initial transmission and retransmission of the uplink data are handled by the same HARQ processor (e.g., HARQ process 4). The ACK / NACK information is transmitted via the PHICH.

[0078] In the LTE(-A) system, the DL HARQ method uses asynchronous adaptive HARQ. Specifically, the base station 110 transmits a DL grant to the terminal 120 through a PDCCH. The terminal 120 receives downlink data from the base station S110 using the RB and MCS specified by the DL grant at the time of receiving the DL grant (e.g., subframe 0). The terminal 120 decodes the downlink data and then generates an ACK / NACK. If the decoding of the downlink data fails, the terminal 120 transmits a NACK to the base station 110 four subframes later (e.g., subframe 4) from the time of receiving the downlink data. Thereafter, the base station 110 transmits a DL grant to the terminal 120 through a PDCCH at a desired time (e.g., subframe X) to instruct the retransmission of downlink data. The terminal 120 re-receives the downlink data from the base station S110 using the RB and MCS specified by the DL grant at the time of receiving the DL grant (e.g., subframe X).

[0079] A base station / terminal has multiple parallel HARQ processes for DL / UL transmission. The multiple parallel HARQ processes allow DL / UL transmission to be performed continuously while waiting for HARQ feedback for successful or unsuccessful reception of previous DL / UL transmission. Each HARQ process is associated with a HARQ buffer in the medium access control (MAC) layer. Each HARQ process manages state variables related to the number of transmissions of MAC PDUs (Physical Data Blocks) in the buffer, HARQ feedback for MAC PDUs in the buffer, current redundancy version, etc.

[0080] The HARQ process is responsible for reliable transmission of data (e.g., a Transport Block (TB)). During channel coding, a Transport Block is divided into one or more Code Blocks (CB) taking into account the size of the channel encoder. After channel coding, one or more Code Blocks are combined to form a Codeword (CW) corresponding to the Transport Block.

[0081] 9 is a diagram illustrating a process of processing a transmission block (TB). The process shown in FIG. 9 can be applied to data of DL-SCH, PCH and MCH (multicast channel) transmission channels. Uplink TB (or data of uplink transmission channel) can be processed in the same manner.

[0082] Referring to FIG. 9, the transmitter adds a CRC (e.g., 24 bits) (TB CRC) to the TB for error checking. Then, the transmitter divides the TB+CRC into multiple code blocks considering the size of the channel encoder. In LTE(-A), the maximum size of a code block is 6144 bits. Therefore, if the TB size is 6144 bits or less, no code block is constructed, and if the TB size is greater than 6144 bits, the TB is divided into 6144-bit units to construct multiple code blocks. A CRC (e.g., 24 bits) (CB CRC) is added to each code block for error checking. After channel coding and rate matching, each code block is assembled to form a codeword. In LTE(-A), data scheduling and the associated HARQ process are performed in units of TB, and the CB CRC is used to determine early termination of TB decoding.

[0083] The HARQ process is associated with a soft buffer for transmission blocks and a soft buffer for code blocks in the PHY (Physical) layer. A circular buffer for JPEG0007601844000004.jpg412 is created as follows:

[0084] [Formula 1] JPEG0007601844000005.jpg44104

[0085] N IR The size of the soft buffer for transmission blocks is N bits. cb N denotes the size of the soft buffer for the rth code block. cb is calculated as follows, where C is the number of code blocks.

[0086] [Formula 2] JPEG0007601844000006.jpg24170

[0087] N IR is as follows.

[0088] [Formula 3] JPEG0007601844000007.jpg2193

[0089] Here, N soft indicates the total number of bits of the soft channel according to the terminal capability.

[0090] If N soft =35982720, k C =5,

[0091] else if N soft = 3654144, and the terminal can support up to two spatial layers for the DL cell, then k C =2

[0092] else K C =1

[0093] End if.

[0094] K MIMOis 2 if the terminal is configured to receive PDSCH transmissions based on transmission modes 3, 4, 8 or 9, and is 1 otherwise.

[0095] M DL_HARQ is the maximum number of DL HARQ processes.

[0096] 0M limit is 8.

[0097] In FDD and TDD, a terminal is configured to have two or more serving cells, and for each serving cell, at least JPEG0007601844000008.jpgIf the decoding of a code block of a transmission block fails for 1258 transmission blocks, the terminal shall at least Store the received soft channel bits corresponding to the range of JPEG0007601844000009.jpg1376. SB can be calculated using the following formula:

[0098] [Formula 4] JPEG0007601844000010.jpg22126

[0099] JPEG0007601844000011.jpg15132

[0100] M DL_HARQ is the maximum number of DL HARQ processes.

[0101] JPEG0007601844000012.jpg1019 is the number of configured serving cells.

[0102] JPEG0007601844000013.jpg1114 indicates the total number of bits for the soft channel according to the terminal capabilities.

[0103] When determining k, the device uses a low value of k. Prioritize the storage of bits in the soft channel corresponding to w kcorresponds to the received soft channel bits. JPEG0007601844000014.jpg1474 may contain a subset that does not include bits of the received soft channel.

[0104] In LTE, scheduling for UL transmission is possible only when the UE's UL transmission timing is synchronized. The random access procedure is used for various purposes. For example, the random access procedure is performed at the time of initial network access, handover, and data generation. The UE can also obtain UL synchronization through the random access procedure. Once UL synchronization is obtained, the base station allocates resources for UL transmission to the UE. The random access procedure is divided into a contention based procedure and a non-contention based procedure.

[0105] FIG. 10 is a diagram illustrating a collision-based random connection process.

[0106] Referring to FIG. 10, the terminal receives information about random access from the base station through system information. Then, if random access is necessary, the terminal transmits a random access preamble (also referred to as message 1) to the base station (S710). When the base station receives the random access preamble from the terminal, the base station transmits a random access response message (also referred to as message 2) to the terminal (S720). Specifically, downlink scheduling information for the random access response message is CRC masked to a Random Access-RNTI (RA-RNTI) and transmitted on an L1 / L2 control channel (PDCCH). The terminal that has received the downlink scheduling signal masked to the RA-RNTI receives and decodes the random access response message from the PDSCH. Then, the terminal checks whether the random access response message indicates to the terminal whether it contains random access response information indicated to the terminal. Whether the random access response information indicated to the terminal contains can be checked by whether a Random Access preamble ID (RAID) exists for the preamble transmitted by the terminal. The random access response information includes a Timing Advance (TA) indicating timing offset information for synchronization, radio resource allocation information used for uplink, a temporary identifier (e.g., T-CRNTI) for identifying the terminal, etc. When the terminal receives the random access response information, the terminal transmits an uplink message (also called message 3) on an uplink Shared Channel (S730) according to the radio resource allocation information included in the response information. After receiving the uplink message from the terminal in S730, the base station transmits a contention resolution message (also called message 4) to the terminal (S740).

[0107] 11 is a diagram illustrating a non-contention based random access procedure. The non-contention based random access procedure is used in a handover procedure or exists when requested by a command from a base station. The basic procedure is the same as the contention based random access procedure.

[0108] Referring to FIG. 11, a terminal is assigned a random access preamble (i.e., a dedicated random access preamble) for itself by a base station (S810). Dedicated random access preamble indication information (e.g., a preamble index) is included in a handover command message or is received via a PDCCH. The terminal transmits the dedicated random access preamble to the base station (S820). Then, the terminal receives a random access response from the base station (S830) and completes the random access process.

[0109] DCI format 1A is used to start a non-collision based random access process by a PDCCH order. DCI format 1A is also used for compact scheduling for one PDSCH codeword. DCI format 1A is used to transmit the following information:

[0110] Flag for distinguishing DCI format 0 / 1A: 1 bit. A flag value of 0 indicates DCI format 0, and a flag value of 1 indicates DCI format 1A.

[0111] DCI format 1A is used for a random access procedure by a PDCCH command if all fields remaining after the CRC of DCI format 1A is scrambled with the C-RNTI are set as follows:

[0112] - Localized / distributed VRB (Virtual Resource Block) allocation flag: 1 bit. The flag is set to 0.

[0113] -Resource block allocation information: JPEG0007601844000015.jpg 1557 bits, all bits set to 1.

[0114] - Preamble index: 6 bits

[0115] - PRACH mask index: 4 bits

[0116] - All remaining bits for compact scheduling of PDSCH codewords in DCI format 1A are set to 0.

[0117] FIG. 12 illustrates a Carrier Aggregation (CA) communication system.

[0118] Referring to FIG. 12, multiple UL / DL component carriers (CCs) can support wider UL / DL bandwidths. The CCs may or may not be adjacent to each other in the frequency domain. The bandwidth of each CC can be determined independently. Asymmetric carriers having different numbers of UL CCs and DL CCs can also be merged. In addition, control information is set so that it can be transmitted and received only through a specific CC. This specific CC is called a primary CC, and the other CCs are called secondary CCs. As an example, when cross-carrier scheduling (or cross-CC scheduling) is applied, a PDCCH for downlink allocation is transmitted to DL CC#0, and a corresponding PDSCH is transmitted to DL CC#2. The term 'component carrier' can be replaced with other equivalent terms (e.g., carrier, cell, etc.).

[0119] For cross-CC scheduling, a carrier indicator field (CIF) is used. The presence or absence of a CIF in a PDCCH is semi-statically enabled by terminal-specific (or terminal group-specific) higher layer signaling (e.g., RRC signaling). The basics of PDCCH transmission are summarized below.

[0120] □■□CIF disabled: A PDCCH on a DL CC allocates a PDSCH resource on the same DL CC or a PUSCH resource on one linked UL CC.

[0121] ● No CIF

[0122] CIF enabled: PDCCH on DL CC can allocate PDSCH or PUSCH resources on a specific DL / UL CC among multiple merged DL / UL CCs using CIF.

[0123] ● LTE DCI format extended to include CIF

[0124] - CIF (if set) is a fixed x-bit field (e.g., X=3)

[0125] - The position of CIF (if set) is fixed regardless of the DCI format size.

[0126] When a CIF exists, the base station can assign a monitoring DL CC (set) to reduce BD complexity on the terminal side. For PDSCH / PUSCH scheduling, the terminal detects / decodes the PDCCH only on the corresponding DL CC. Also, the base station can transmit the PDCCH only through the monitoring DL CC (set). The monitoring DL CC set is set in a terminal-specific, terminal-group-specific, or cell-specific manner.

[0127] FIG. 13 illustrates scheduling when multiple carriers are merged. This illustrates a case where three DL CCs are merged and DL CCA is set as the PDCCH monitoring DL CC. DL CCs C to C can be called serving CCs, serving carriers, serving cells, etc. When CIF is disabled, each DL CC can transmit only a PDCCH that schedules its own PDSCH without a CIF according to the LTE PDCCH rules (non-cross-CC scheduling). On the other hand, when CIF is enabled by UE-specific (or UE-group-specific or cell-specific) higher layer signaling, a specific CC (e.g., DL CC A) can transmit not only a PDCCH that schedules DL CC A's PDSCH using CIF, but also a PDCCH that schedules another CC's PDSCH (cross-CC scheduling). On the other hand, DL CC B / C does not transmit PDCCH.

[0128] On the other hand, millimeter wave (mmW) signals have a short wavelength, so multiple antennas can be installed in the same area. For example, in the 30 GHz band, the wavelength is 1 cm, so a total of 100 antenna elements can be installed in a two-dimensional array with 0.5 λ (wavelength) intervals on a 5x5 cm panel. Therefore, in mmW systems, multiple antenna elements can be used to increase beamforming (BF) gain to increase coverage or improve throughput.

[0129] In this regard, a TXRU (transceiver) is provided so that the transmission power and phase can be adjusted for each antenna element, and independent beamforming can be performed for each frequency resource. However, providing a TXRU for all 100 antenna elements is not cost-effective. Therefore, a method of mapping multiple antenna elements to one TXRU and adjusting the beam direction with an analog phase shifter is considered. This analog beamforming method has the disadvantage that it is difficult to form frequency-selective beamforming because only one beam direction can be formed in the entire band. As an intermediate form between the digital beamforming and analog beamforming, a hybrid beamforming having B TXRUs, which is less than the Q antenna elements, is considered. In this case, although there are differences depending on the connection method of the B TXRUs and the Q antenna elements, the number of beam directions that can be transmitted simultaneously is limited to B or less.

[0130] Figure 14 is a diagram illustrating analog beamforming. Referring to Figure 14, a transmitter can change the beam direction over time to transmit a signal (transmit beamforming), and a receiver can also change the beam direction over time to receive a signal (receive beamforming). Within a certain time period, (i) the beam directions of the transmit beam and receive beam can change simultaneously over time, (ii) the transmit beam can be fixed and only the receive beam can change over time, or (iii) the receive beam can be fixed and only the transmit beam can change over time.

[0131] Meanwhile, in the next generation RAT (Radio Access Technology), a self-contained subframe is considered to minimize data transmission latency. FIG. 15 illustrates the structure of a self-contained subframe. In FIG. 15, the shaded area indicates the DL control area, and the black area indicates the UL control area. The other areas are used for DL ​​data transmission or UL data transmission. Since DL transmission and UL transmission are performed in sequence within one subframe, it is possible to transmit DL data and receive UL ACK / NACK within the subframe. As a result, it is possible to minimize the delay of final data transmission by shortening the time required for data retransmission when a data transmission error occurs.

[0132] There are at least four possible self-contained subframe types that can be configured:

[0133] -DL control section + DL data section + GP (Guard Period) + UL control section

[0134] -DL control section + DL data section

[0135] -DL control section + GP + UL data section + UL control section

[0136] -DL control section + GP + UL data section

[0137] PDFICH, PHICH, and PDCCH are transmitted in the DL control section, and PDSCH is transmitted in the DL data section. PUCCH is transmitted in the UL control section, and PUSCH is transmitted in the UL data section. GP provides a time gap when the base station and the terminal switch from transmission mode to reception mode or from reception mode to transmission mode. Some OFDM symbols at the time of switching from DL to UL within a subframe are set as GP.

[0138] Working Example

[0139] In the case of the existing LTE system, when the size of DL data (i.e., TBS) exceeds a certain level, the bit stream (i.e., TB) transmitted through the PDSCH is divided into multiple CBs, and channel coding and CRC are applied to each CB (see FIG. 9). If the terminal fails to receive (e.g., decode) any one of the multiple CBs included in one TB, it reports the HARQ-ACK feedback corresponding to the corresponding TB as a NACK to the base station. As a result, the base station retransmits all the CBs corresponding to the corresponding TB. In other words, in the existing LTE(-A), the HARQ operation for DL ​​data is performed based on the scheduling / transmission in units of TB from the base station and the corresponding HARQ-ACK feedback configuration in units of TB from the terminal.

[0140] Meanwhile, a next generation RAT (hereinafter, referred to as new RAT) system basically has a wider system (carrier) BW (bandwidth) than LTE, and therefore the (maximum) TBS is likely to be wider than that of the existing LTE. Therefore, the number of CBs constituting one TB is also greater than that of LTE. Therefore, if HARQ-ACK feedback is performed in units of TBs as in the past in the new RAT system, even if a decoding error (i.e., NACK) occurs only in some CBs, retransmission scheduling is performed in units of TBs, which reduces the efficiency of resource usage. In addition, in the new RAT system, a delay-sensitive data type 2 (e.g., Ultra-Reliable Low Latency Communications, URLLC) having a small time interval (TTI) can be transmitted in a form of puncturing data type 1 through a part (symbol) of resources allocated to the transmission of a delay-insensitive data type 1 (e.g., enhanced Mobile Broadband, eMBB) having a large time interval (TTI). Furthermore, due to the influence of an interference signal having time-selective characteristics, a phenomenon occurs in which decoding errors (i.e., NACKs) are concentrated in only a certain portion of the multiple CBs that make up one TB for data type 1.

[0141] In the present invention, in consideration of the characteristics of the new RAT system, a method of performing (retransmission) scheduling in units of CB or CBG (CG group) and configuring / transmitting HARQ-ACK feedback in units of CB / CBG is proposed. In detail, the present invention proposes a method of configuring CBG, a method of configuring HARQ-ACK (hereinafter, A / N) feedback, a method of operating a receiving soft buffer of a terminal, and a method of handling a specific mismatch situation.

[0142] For convenience, the proposed method of the present invention is divided into various embodiments, which are for convenience of explanation only and may be used in combination with each other.

[0143] First, the abbreviations / terms used in the present invention will be explained.

[0144] -TBS: TB size, the total number of bits that make up a TB

[0145] -CB: Code Blocks

[0146] -CB size: The total number of bits that make up the CB

[0147] CBG: Code Block Group. All CBs (constituting a single TB) are configured as one CBG, or some CBs are configured as one CBG, or each CB is configured as one CBG.

[0148] -A / N: Response to HARQ-ACK, i.e. ACK, NACK, DTX. DTX indicates a missed PDCCH. The A / N bit is set to 1 for ACK and 0 for NACK. It can be used equivalently to HARQ-ACK and ACK / NACK.

[0149] -CBG-based A / N: Since no CRC is added to the CBG, an A / N for the CBG can be generated based on the error check result for the CB in the CBG. For example, if all CBs in the CBG are successfully detected, the terminal sets the A / N response (or A / N bit) for the CBG to ACK, and if any CB in the CBG is not successfully detected, the terminal sets the A / N response (or A / N bit) for the CBG to NACK (logical AND). The A / N payload for (multiple) CBGs of a TB includes multiple A / N (response) bits, and each A / N (response) bit corresponds 1:1 to the CBG of the TB.

[0150] -CBG-based retransmission: TB retransmission can be performed on a CBG basis according to the CBG-based A / N. For example, when the base station retransmits a TB to a terminal, it can perform retransmission only for the CBG for which it has received a NACK from the terminal. In this case, when the TB is retransmitted corresponding to the same HARQ process as the previous transmission of the TB, the CB(s) in the CBG are maintained in the same manner as when the TB was initially transmitted.

[0151] -CBG size: the number of CBs that make up the CBG

[0152] -CBG index: An index that distinguishes CBG. Depending on the context, a CBG index can be used equivalently to a CBG having the corresponding index.

[0153] - Symbol: Unless otherwise specified, this refers to an OFDMA symbol or an SC-FDMA symbol.

[0154] -floor(X): The floor function, which means the largest constant less than or equal to X.

[0155] -ceiling(X): The ceiling function, which means the smallest constant greater than or equal to X.

[0156] -mod(A,B): The remainder when A is divided by B.

[0157] How to configure (X)CB

[0158] 1) Method X-1: The number of bits that make up one CB, Cn, is given, and Cm CBs are constructed based on this.

[0159] The number of bits Cn constituting one CB is predefined to be the same value regardless of the TBS or a different value for each TBS (e.g., proportional to the TBS), or is indicated to the terminal through semi-static signaling (e.g., RRC signaling) or dynamic signaling (e.g., DCI). Thus, when the total number of bits constituting the TB is Ck, Cm=floor(Ck / Cn) or Cm=ceiling(Ck / Cn) CBs are configured. In the former case, only one CB is configured with (Cn+mod(Ck,Cn)) bits, and the other (Cm-1) CBs are each configured with Cn bits. In the latter case, only one CB is configured with mod(Ck,Cn) bits, and the other (Cm-1) CBs are each configured with Cn bits. In the former case, Cn means the minimum number of bits constituting one CB, and in the latter case, Cn means the maximum number of bits constituting one CB.

[0160] Alternatively, a method of allocating the number of bits per CB evenly to all CBs (near-equal) can be applied. For example, in the above case, when Cm=floor(Ck / Cn) CBs are configured, mod(Ck,Cn) CBs are configured with (Cn+1) bits, and the other CBs are configured with Cn bits. Also, when Cm=ceiling(Ck / Cn) CBs are configured, (Cn-mod(Ck,Cn)) CBs are configured with (Cn-1) bits, and the other CBs are configured with Cn bits. In the former case, Cn means the minimum number of bits that make up one CB, and in the latter case, Cn means the maximum number of bits that make up one CB.

[0161] Furthermore, by applying the above method, one or more specific CBs (hereinafter, small CBs) among the total Cm CBs can be configured with a smaller number of bits than the other CBs (hereinafter, regular CBs). Therefore, a method is required for grouping Cm CBs having unequal sizes into M CBGs. Specifically, it can be divided into cases where the total number of CBs Cm is a multiple of the number of CBGs M and cases where it is not, and the following CB grouping methods can be considered for each case. Hereinafter, CBG size means the number of CBs per CBG. Note that when Cm is not a multiple of M, the size differs for each CBG, and the size difference between CBGs is limited to a maximum of one CB.

[0162] A. If Cm is a multiple of M (all CBGs have the same size)

[0163] -Opt 1-1: Small CBs are distributed to all CBGs as much as possible.

[0164] -Opt 1-2: Small CBs are configured to belong to only a small number of CBGs as possible.

[0165] If B.Cm is not a multiple of M (sizes vary by CBG)

[0166] -Opt 2-1: Configure small CBs to belong to the largest possible CBG

[0167] -Opt 2-2: Small CBs are configured to belong to the smallest possible CBG

[0168] -Opt 2-3: Apply Opt 1-1 or Opt 1-2

[0169] As an example, when Cm=7 and CB indexes 1 / 2 / 3 / 4 / 5 / 6 / 7 are each configured with 5 / 5 / 5 / 5 / 5 / 5 / 2 bits, M=3 CBG configurations can be considered. Here, when Opt 2-1 is applied, CB indexes {1,2}, {3,4}, {5,6,7} can be configured with CBG indexes 1 / 2 / 3, respectively, and when Opt 2-2 is applied, CB indexes {1,2,3}, {4,5}, {6,7} can be configured with CBG indexes 1 / 2 / 3, respectively. As another example, when Cm=7 and CB indexes 1 / 2 / 3 / 4 / 5 / 6 / 7 are each configured with 5 / 5 / 5 / 5 / 4 / 4 / 4 bits, M=3 CBG configurations can be considered. Here, when Opt 2-1 is applied, CB indexes {1,2}, {3,4}, {5,6,7} can be configured with CBG indexes 1 / 2 / 3, and when Opt 2-2 is applied, CB indexes {1,2,3}, {4,5}, {6,7} can be configured with CBG indexes 1 / 2 / 3, respectively. On the other hand, when Opt 1-1 is applied, CB indexes {1,2,5}, {3,6}, {4,7} can be configured with CBG indexes 1 / 2 / 3, and when Opt 1-2 is applied, CB indexes {1,2}, {3,4}, {5,6,7} can be configured with CBG indexes 1 / 2 / 3, respectively.

[0170] Furthermore, the number of CBs in the CBG corresponding to the part where the decoding reliability may be low can be minimized to minimize the size of the CBG where the probability of retransmission is high. For example, the decoding reliability may be low when the CB size of the wireless signal is relatively small, the wireless signal is far away in time from the DMRS, the wireless signal is far away from the CSI feedback time, or the wireless signal is mapped to an (OFDMA / SC-FDMA) symbol adjacent to the SRS (or PUCCH or PRACH). For this purpose, the CBG can be configured as follows.

[0171] a) A regular CB is constructed in units of X bits from a low CB index, and a small CB is constructed in units of Y bits from a specific CB index (Y <X)。

[0172] b) (In order from the CBs with a low CB index) Group the regular CBGs in units of M CBs in order from the low CB index, and group the small CBGs in units of K CBs starting from a specific CBG index (K < M). Here, as described above, the size difference between CBGs is limited to at most one CB (for example, M = K + 1). According to a) and b), compared to the CBGs with a low index, the CBGs with a high index have a relatively small CBG size and can have more small CBs even if the CBG sizes are the same.

[0173] c) Map the signals in a frequency - first (or time - first) manner in order from the CBGs with a low CBG index. Here, compared to the CBGs with a high index, the CBGs with a low index can be mapped to resources with relatively high decoding reliability.

[0174] Note that when Cn > Ck, all bits of the TB are configured in the form of being composed of a single CB, and one CB containing Ck bits can be formed.

[0175] 2) Method X - 2: Given the total number of CBs Cm, each CB is configured based on this in units of Cn bits.

[0176] The total number of CBs, Cm, is predefined to be the same value regardless of the TBS or a different value for each TBS (e.g., proportional to the TBS), or is indicated to the terminal through semi-static signaling (e.g., RRC signaling) or dynamic signaling (e.g., DCI). As an example, when the total number of bits constituting the TB is Ck, each CB is configured in units of Cn=floor(Ck / Cm) or Cn=ceiling(Ck / Cm) bits. In the former case, only one CB is configured with (Cn+mod(Ck,Cn)) bits, and the other (Cm-1) CBs are each configured with Cn bits. In the latter case, only one CB is configured with mod(Ck,Cn) bits, and the other (Cm-1) CBs are each configured with Cn bits. In the former case, Cn means the minimum number of bits constituting one CB, and in the latter case, Cn means the maximum number of bits constituting one CB.

[0177] As another method, a method of uniformly allocating the number of bits per CB to all CBs can be applied. For example, in the above case, when CBs are configured in units of Cn=floor(Ck / Cm) bits, mod(Ck,Cm) CBs are configured with (Cn+1) (or ceiling(Ck / Cm)) bits, and the other (Cm-mod(Ck,Cm)) CBs are configured with Cn bits. When CBs are configured in units of Cn=ceiling(Ck / Cm) bits, (Cn-mod(Ck,Cm)) CBs are configured with (Cn-1) (or floor(Ck / Cm)) bits, and the other mod(Ck,Cm) CBs are configured with Cn bits. In the former case, Cn means the minimum number of bits that constitute one CB, and in the latter case, Cn means the maximum number of bits that constitute one CB.

[0178] 3) Method X-3: The minimum number of bits Tm that constitute one CB is given, and the CB is constructed based on this.

[0179] All the CBs that make up one TB can be set so that they are each composed of at least Tm bits. As an example, when assuming that TBS is Ck, the maximum Cm value Cm.max that satisfies the relational expression Ck / Cm ≥ Tm is calculated, and the operation of dividing the corresponding TB into Cm.max CBs can be considered.

[0180] 4) Method X-4: When the number of CBs is at a specific level or higher, perform scheduling for each CB unit and grouping among multiple CBs

[0181] It can be set / defined so that (retransmission) scheduling for each CB or CBG unit is applied to the corresponding TB only when the number K of all the CBs that make up one TB is Ts or more. Also, when the total number K of CBs is Tg or more, it can be set / defined so that a plurality of CBs are grouped to form one CBG (for example, Ts < Tg). Here, the number Cn of bits that make up one CB is predefined or given through specific signaling (for example, RRC signaling, DCI).

[0182] (A) Method for forming a CBG

[0183] 1) Method A-1: The number N of CBs that make up one CBG is given, and based on this, M CBGs are formed

[0184] The number N of CBs constituting one CBG is predefined as the same value regardless of the TBS or a different value for each TBS (e.g., proportional to the TBS), or is indicated to the terminal through semi-static signaling (e.g., RRC signaling) or dynamic signaling (e.g., DCI). As an example, when the total number of CBs constituting a TB is K, M=floor(K / N) or M=ceiling(K / N) CBGs are configured. In the former case, only one CBG is configured with (N+mod(K,N)) CBs, and the other (M-1) CBGs are each configured with N CBs. In the latter case, only one CBG is configured with mod(K,N) CBs, and the other (M-1) CBGs are each configured with N CBs. In the former case, N means the minimum number of CBs constituting one CBG, and in the latter case, N means the maximum number of CBs constituting one CBG. In addition, the terminal can configure and transmit an A / N bit for each CBG.

[0185] Alternatively, a method of uniformly allocating the number of CBs per CBG to all CBGs can be applied. For example, in the above case, when M=floor(K / N) CBGs are configured, mod(K,N) CBGs are configured with (N+1) CBs, and other CBGs are configured with N CBs. When M=ceiling(K / N) CBGs are configured, (N-mod(K,N)) CBGs are configured with (N-1) CBs, and other CBGs are configured with N CBs. In the former case, N means the minimum number of CBs that make up one CBG, and in the latter case, N means the maximum number of CBs that make up one CBG.

[0186] In addition, when N>K, all CBs constituting the TB belong to a single CBG, and one CBG including K CBs can be constructed.

[0187] 2) Method A-2: Given the total number of CBGs, M, construct each CBG in units of N CBs based on this.

[0188] The total number M of CBGs is predefined to be the same value regardless of TBS or a different value for each TBS (e.g., proportional to TBS), or is indicated to the terminal through semi-static signaling (e.g., RRC signaling) or dynamic signaling (e.g., DCI). The terminal can identify / configure CBGs from a plurality of CBs of the TB based on the total number M of CBGs. As an example, when the total number of CBs constituting the TB is K, each CBG is configured in units of N=floor(K / M) or N=ceiling(K / M) CBs. In the former case, only one CBG is configured with (N+mod(K,N)) CBs, and the other (M-1) CBGs are each configured with N CBs. In the latter case, only one CBG is configured with mod(K,N) CBs, and the other (M-1) CBGs are each configured with N CBs. In the former case, N means the minimum number of CBs constituting one CBG, and in the latter case, N means the maximum number of CBs constituting one CBG. In addition, the terminal can configure and transmit an A / N bit for each CBG. For example, the terminal can configure M A / N bits for the TB, and each A / N bit can indicate the A / N result for the corresponding CBG.

[0189] Alternatively, a method of uniformly allocating the number of CBs per CBG to all CBGs can be applied. For example, in the above case, when the CBG configuration is in units of N=floor(K / M)) CBs, the mod(K,M) CBGs are composed of (N+1) (or ceiling(K / M)) CBs, and the other (M-mod(K,M)) CBGs are composed of N (or floor(K / M)) CBs. Also, when the CBG configuration is in units of N=ceiling(K / M) CBs, the (M-mod(K,M)) CBGs are composed of (N-1) (or floor(K / M)) CBs, and the other mod(K,M) CBGs are composed of N (or ceiling(K / M)) CBs. In the former case, N means the minimum number of CBs constituting one CBG, and in the latter case, N means the maximum number of CBs constituting one CBG.

[0190] In addition, when M>K, each CB becomes one CBG, and a total of K CBGs can be configured. In this case, 1) with the entire A / N feedback configured with M bits, (MK) bits that do not actually correspond to a CBG are processed as NACK or DTX, or 2) a method is considered in which the A / N feedback itself is configured with only K bits that correspond to the actual CBG.

[0191] FIG. 16 is a diagram illustrating a signal transmission process according to the present invention.

[0192] Referring to FIG. 16, the terminal may receive information on the number M of code block groups per transmission block from the base station through an upper layer signal (e.g., an RRC signal) (S1602). Then, the terminal may receive an initial data transmission from the base station (through a PDSCH) (S1604). Here, the data includes a transmission block, the transmission block includes a plurality of code blocks, and the plurality of code blocks are divided into one or more code block groups. Here, some of the code block groups include ceiling (K / M) code blocks, and the other code blocks include flooring (K / M) code blocks. K indicates the number of code blocks in the data. Then, the terminal may feed back code block group-based A / N information for the data to the base station (S1606), and the base station may perform data retransmission based on the code block group (S1608). The A / N information is transmitted through a PUCCH or a PUSCH. Here, the A / N information includes a plurality of A / N bits for the data, and each A / N bit may indicate each A / N response generated for the data on a code block group basis. The size of the payload of the A / N information remains the same based on M regardless of the number of code block groups that make up the data.

[0193] 3) Method A-3: Construct a CBG based on a tree (or nested) structure for the number of CBGs M and the size of the CBG N.

[0194] The CBGs are configured to have a tree structure with respect to the total number M of CBGs (e.g., M1, M2, …) and the size N of CBGs (e.g., N1, N2, …). In this case, for one TB (size), a plurality of different CBG configurations based on a plurality of different (M, N) combinations can be set. Considering the CBG configurations in the cases of (M1, N1) and (M2, N2) for different (M, N) combinations, when M1 < M2, N1 > N2 can be set. Also, one CBG in the case of (M1, N1) can be configured to include one or more CBGs in the case of (M2, N2). Conversely, one CBG in the case of (M2, N2) can be configured to belong to only a specific one CBG in the case of (M1, N1). Also, M2 is set to be a multiple of M1 or is set such that M1 is a multiple of M2, and N1 is set to be a multiple of N2. M can be set to 2 m (m = 0, 1, …). Note that one (or more) of the indices for M, N, or the (M, N) combination, or the possible CBG indices based on all (M, N) combinations, is / are indicated to the terminal through semi-static signaling (e.g., RRC signaling) or dynamic signaling (e.g., DCI). The terminal can configure and transmit A / N bits for each CBG configured corresponding to the relevant index. M and N are predefined to be the same one value regardless of the TBS, or are predefined to be different (e.g., proportional to the TBS) values for each TBS.

[0195] As an example, assuming that the total number of CBs constituting the TB is K = 16, and each CB is indexed as k = 0, 1, …, 15, a method of setting the number of CBGs to M = {1, 2, 4, 8, 16} and setting the corresponding size of each CBG to N = K / M = {16, 8, 4, 2, 1} can be considered (nested CBG example 1).

[0196] a) In the case of (M, N) = (1, 16), only one CBG is configured, and the corresponding CBG includes all 16 CBs.

[0197] b) When (M,N)=(2,8), two CBGs are constructed, each containing eight distinct CBs. In this case, one CBG contains two CBGs when (M,N)=(4,4).

[0198] c) When (M,N)=(4,4), four CBGs are constructed, each containing four different CBs. In this case, one CBG contains two CBGs when (M,N)=(8,2).

[0199] d) If (M,N)=(8,2), eight CBGs are constructed, each containing two distinct CBs.

[0200] e) If (M,N)=(16,1), 16 CBGs are constructed, each containing only one distinct CB.

[0201] As described above, with a plurality of different (M,N) combinations and the number / size of CBGs therefor configured / specified in advance, an index of a specific M,N or (M,N) combination, or one (or more) of possible CBGs based on all (M,N) combinations, may be indicated to the terminal. In the above example, there are a total of five possible M, N or (M,N) combinations, and the possible CBG indexes for all (M,N) combinations are set to a total of 31 types (corresponding to the sum of possible M values ​​{1,2,4,8,16}). The terminal may decode scheduled DL data (e.g., TB or CBG) and configure / transmit corresponding A / N feedback assuming a CBG configuration corresponding to the M and / or N index.

[0202] Generalize this method. For the CBG configurations in the cases of (M1, N1) and (M2, N2) which are different combinations of (M, N), when M1 < M2, multiple CBG configurations can be set for one TB (size) only under the condition that N1 ≥ N2. As an example, assuming the total number of CBs constituting the TB is K = 6, with each CB indexed as k = 0, 1, 2, …, 5, a method can be considered where the number of CBGs is set to M = {1, 2, 3, 6}, and the corresponding size of each CBG is set to N = K / M = {6, 3, 2, 1} (nested CBG example 2).

[0203] a) In the case of (M, N) = (1, 6), only one CBG is configured, and the corresponding CBG includes all six CBs.

[0204] b) In the case of (M, N) = (2, 3), two CBGs are configured, and each CBG includes three different CBs. For example, the CB index sets {0, 1, 2} and {3, 4, 5} each form one CBG.

[0205] c) In the case of (M, N) = (3, 2), three CBGs are configured, and each CBG includes two different CBs. For example, the CB index sets {0, 1}, {2, 3}, and {4, 5} each form one CBG.

[0206] d) In the case of (M, N) = (6, 1), six CBGs are configured, and each CBG includes only one different CB.

[0207] As another example, assuming the total number of CBs constituting the TB is K = 9, with each CB indexed as k = 0, 1, …, 8, a method can be considered where the number of CBGs is set to M = {1, 2, 3, 6}, and the corresponding size of each CBG is set to N = {9, (5 or 4), 3, (2 or 1)} (nested CBG example 3).

[0208] a) In the case of (M, N) = (1, 9), only one CBG is configured, and the corresponding CBG includes all nine CBs.

[0209] b) If (M,N)=(2,5, or 4), then a total of two CBGs are constructed, one with five CBs and the other with four CBs. For example, the CB index sets {0,1,2,3,4} and {5,6,7,8} each construct one CBG.

[0210] c) When (M,N)=(3,3), three CBGs are constructed, each containing three distinct CBs. For example, the CB index sets {0,1,2}, {3,4,5}, and {6,7,8} each constitute one CBG.

[0211] d) If (M,N)=(6,2, or 1), a total of 6 CBGs are constructed, of which 3 CBGs contain 2 CBs and the other 3 CBGs contain 1 CB each. For example, the CB index sets {0,1}, {2,3}, {4,5}, {6}, {7}, and {8} each constitute one CBG.

[0212] In the case of nested CBG examples 2 and 3, a total of 12 (=1+2+3+6) CBGs configured (based on four different (M,N) combinations) can be indexed. Based on this, the base station indicates / indicates (through DCI) the CBG to be scheduled for retransmission, and the UE can configure and transmit A / N feedback for the indicated CBG.

[0213] In addition, taking into consideration the DCI overhead for indicating the CBG to be scheduled and / or the UCI overhead for configuring the corresponding A / N feedback, the number L of all CBG indexes configured in a nested form is set to be the same for each TBS, or the bit overhead for indicating the CBG for each TBS is set to be the same (for example, ceiling(log 2 (L) The L value can be set for each TBS so that the L values ​​are the same.

[0214] 4) Method A-4: Multiple CBs belonging to a specific number of symbol sets (and a specific number of RB sets) are configured into one CBG.

[0215] With a time interval (and / or frequency domain) in which a TB is transmitted divided into a plurality of symbol groups (hereinafter, Symbol Groups, SGs) (and / or a plurality of RB groups (hereinafter, RB Groups, RBGs)), a plurality of CBs transmitted through each SG (and / or each RBG) can be configured as one CBG. In this case, information regarding the number of symbols in each SG or the number of symbols constituting a single SG (and / or the number of RBs in each RBG or the number of RBs constituting a single RBG) is indicated to the terminal through semi-static signaling (e.g., RRC signaling) or dynamic signaling (e.g., DCI). When receiving DL data, the terminal can configure and transmit an A / N bit for each CBG.

[0216] Also, the number of symbols constituting one SG or the total number of SGs configured in the time period of TB transmission (and / or the number of RBs constituting one REG or the total number of RBGs configured in the frequency domain of TB transmission) may be configured to have a tree structure as in method A-3. Based on nested CBG examples 1, 2, and 3, for example, the total number of symbols (or RBs) constituting the TB may be assumed to be K=16, 6, or 9, and each symbol (or RB) may be indexed to k=0 to 15, k=0 to 5, or k=0 to 8. In this state, a plurality of SGs (or RBGs) having a nested structure relationship with each other in a form similar to nested CBG examples 1, 2, and 3 may be configured. Also, the size / number of SGs (and / or RBGs) may be predefined to the same value regardless of the TBS, or may be predefined to a different value (for example, proportional to the TBS) for each TB.

[0217] In addition, when one CB is mapped / transmitted across multiple SGs (and / or RBGs), the corresponding CB can be defined as being included in the CBG corresponding to the SG (and / or RBG) with the lowest or highest symbol index (Opt 1), or being included in the CBG corresponding to the SG (and / or RBG) that includes the most coded bits of the corresponding CB (Opt 2).

[0218] Alternatively, when one CB is mapped / transmitted across multiple SGs (and / or RBGs), in terms of CBG configuration / indication for (retransmission) scheduling in the base station, the corresponding CB can be configured to be included in all of the multiple CBGs corresponding to the multiple SGs ( / RBGs). On the other hand, in terms of A / N feedback configuration for each CBG in the terminal, the corresponding CB can be included only in a CBG corresponding to a specific one of the multiple SGs ( / RBGs), and an A / N bit can be configured and transmitted for each CBG. In this case, the terminal can select a specific CBG including the corresponding CB (when configuring A / N feedback) as follows.

[0219] 1) If the decoded result of the corresponding CB is a NACK, if there are CBGs (from a scheduling perspective, among all the multiple CBGs including the corresponding CB) that contain a CB that is a NACK even excluding the corresponding CB, one of them (based on the application of Opt 1 / 2) is selected, and if no such CBG exists, one of them (based on the application of Opt 1 / 2) is selected from all the multiple CBGs (including the corresponding CB) from a scheduling perspective.

[0220] 2) Even if the decoded result of the corresponding CB is ACK, one of all multiple CBGs (including the corresponding CB from the perspective of scheduling) is selected (based on the application of Opt 1 / 2).

[0221] In addition, when multiple CBGs including the same CB are scheduled simultaneously, the corresponding CB can be transmitted only once. For example, the corresponding CB can be transmitted in a form included in only one of the corresponding CBGs (based on the application of Opt 1 / 2).

[0222] This method can be generalized to the case where, in terms of CBG configuration / instruction for base station scheduling, one CB is configured to be included in multiple CBGs in common, and in terms of the terminal configuring A / N feedback for each CBG, the CB is configured to be included in only one of the multiple CBGs in common. As an example, when a total of K CBs are configured with M CBGs, all CBGs can be configured to include the same number of CBs per CBG, N=ceiling(K / M). At this time, some of the M CBGs are configured to include a specific CB in common. For example, in a CBG set smaller than M, any two CBGs include one CB in common, and the total number of CBs included in any two CBGs is (M-mod(K,M)).

[0223] As another method, in order to prevent one CB from being mapped / transmitted across multiple SGs (and / or RBGs) or to make the number of data bits belonging to each CBG as uniform as possible between CBGs, the following method can be considered. Assuming that the scheduled TBS is A bits and the number of SGs or RBGs (generalized CBGs) allocated to the corresponding TBS is M, first, (A / M) or ceiling(A / M) or floor(A / M) data bits are allocated to each CBG. Next, multiple CBs belonging to each CBG can be configured by applying method X-1 / 2 / 3 with the number of data bits allocated to each CBG substituted by the number of bits Ck corresponding to the TBS in method X-1 / 2 / 3. In addition, coded bits for a single CBG can be mapped / transmitted to only one SG or RBG.

[0224] In addition, a method of changing the number of symbols constituting one SG depending on the number of symbols and / or the number of RBs (or TBS) allocated to data transmission is also possible. For example, the larger the number of symbols allocated to data transmission (to make the number of CBGs as uniform as possible), the larger the number of symbols per SG is configured. Also, the larger the number of RBs (or TBS) allocated to data transmission (to make the CBG size as uniform as possible), the smaller the number of symbols per SG is configured. Similarly, a method of changing the number of RBs constituting one RBG depending on the number of RBs and / or the number of symbols (or TBS) allocated to data transmission is also possible. For example, the larger the number of RBs allocated to data transmission (to make the number of CBGs as uniform as possible), the larger the number of RBs per RBG is configured. Also, the larger the number of symbols (or TBS) allocated to data transmission (to make the CBG size as uniform as possible), the smaller the number of RBs per RBG is configured.

[0225] 5) Method A-5: The total number of CBGs M and the size of CBG N are configured for each TBS.

[0226] A (M,N) combination for CBG configuration can be set (differently) for each TBS. During data scheduling, the number of DCI bits for CBG indication and / or the size of the UCI payload for the corresponding A / N feedback configuration is determined based on the maximum value M.max among the M values ​​set for each TBS. As an example, the size of the CBG indication information and / or the A / N payload can be set to M.max, ceiling(M.max / K) or ceiling(log 2 (M.max) bits, where K is a positive constant, e.g., K=2.

[0227] Furthermore, if a set of (M,N) combinations applied to each TBS is called a TBS-CBG table, a method may be considered in which a plurality of TBS-CBG tables are defined / configured in advance and one of the plurality of TBS-CBG tables is indicated to a terminal through semi-static signaling (e.g., RRC signaling) or dynamic signaling (e.g., DCI). In this case, the (M,N) combination corresponding to the same TBS may be configured to be different among the plurality of TBS-CBG tables. Thus, the terminal may refer to the indicated TBS-CBG table, determine the (M,N) combination corresponding to the TBS indicated through the DL / UL scheduling DCI, and transmit / receive DL / UL data and transmit A / N feedback based on the determined (M,N) combination.

[0228] Alternatively, the entire TBS set may be divided into a plurality of TBS ranges, and a different CBG configuration method may be applied to each TBS range. As an example, the number M of CBGs may be configured differently (or the CBG size N may be the same) for TBS range 1, while the number M of CBGs may be configured the same for TBS range 2, or the number M of CBGs may be configured the same for each TBS, in consideration of DCI overhead and / or UCI payload. In this case, TBS range 2 may be configured with a larger TBS than the TBS belonging to TBS range 1, in consideration of DCI overhead and / or UCI payload. As another example, the same CBG configuration (e.g., the number / size of CBGs) may be applied to each TBS range, and the number / size of CBGs may be configured differently between TBS ranges. As an example, the number M of CBGs may be configured the same for each of TBS ranges 1 and 2, or the number M of CBGs may be configured the same for each of TBS ranges 1 and 2, and different M values ​​may be set for TBS ranges 1 and 2. In this case, M of TBS range 2 may be set to a value larger than M of TBS range 1. As another example, for each of TBS ranges 1 and 2, the CBG size N may be configured to be the same for each TBS according to method A-1, and different N values ​​may be set for TBS ranges 1 and 2. In this case, N for TBS range 2 may be set to a value larger than N for TBS range 1.

[0229] 6) Method A-6: Applying interleaving between CBs belonging to the same CBG before data-to-resource mapping

[0230] Considering the influence of interference (e.g., URLLC puncturing operation) having a specific (e.g., time-selective) pattern, inter-CB interleaving may be applied between multiple CBs (coded bits) belonging to the same CBG before data-to-resource (e.g., RE) mapping. As an example, for multiple CBs (coded bits) belonging to one CBG, 1) intra-CB interleaving may be first applied within each CB, and then inter-CB interleaving may be further applied, or 2) (when CBG-based HARQ operation is configured) only inter-CB interleaving may be applied with intra-CB interleaving omitted. Here, data-to-resource mapping includes, for example, RE mapping based on a frequency-first manner.

[0231] In all the above proposed methods, M, N, and K can be set / indicated to the same value for different TBSs, or set / indicated to different values ​​for different TBSs, or some (e.g., N) can be set to the same value and others (e.g., M, K) can be set to different values ​​depending on the TBS. In addition, when considering a method in which one DL data scheduling / transmission is performed across multiple slots, one symbol set (SG) is configured / set based on the slot in the above proposed methods (in this case, the symbol index is applied instead of the slot index).

[0232] (B) HARQ-ACK feedback method

[0233] 1) Method B-1: Construct / transmit the (minimum) range that includes all NACKs on the CBG index as feedback

[0234] In consideration of decoding errors (i.e., NACKs) on consecutive CBG indexes due to time-selective interference when a CBG configuration method (e.g., the number / size of CBGs) is given, the UE may 1) feed back to the base station the CBG index that is the first NACK and the CBG index that is the last NACK (on the CBG index), or 2) feed back the CBG index that is the first NACK and the distance between the first NACK and the last NACK. Here, 1) and 2) may be signaled using a Resource Indication Value (RIV) indication method applied to UL resource allocation type 0 or a combinatorial index method applied to UL resource allocation type 1. In this case, the CBG configuration method may include methods A-1 / 2 / 3 / 4.

[0235] In addition, the terminal can directly select one of a number of CBG configuration methods (e.g., the number / size of CBGs) and, based on the selected CBG configuration, 1) determine the (smallest) CBG range in which NACK is included as described above and feed back the corresponding NACK CBG range and the configuration information of the selected CBG together to the base station, or 2) configure an A / N bit for each CBG individually and feed back the same to the base station (together with the selected CBG configuration information). In this case, the CBG configuration method can include method A-1 / 2 / 3 / 4.

[0236] Furthermore, the above method can also be applied to CBG scheduling from the base station. Specifically, 1) the first and last CBG indexes to be (re)transmitted, or 2) the first CBG index and the total number L of CBGs to be (re)transmitted can be indicated through DL data scheduling DCI. In this case, the terminal can perform (reception) operations under the assumption that 1) a set of CBGs corresponding to indexes between the first and last CBG indexes, or 2) a CBG set corresponding to L consecutive indexes including the first CBG index, has been scheduled.

[0237] 2) Method B-2: In a tree-structured CBG configuration, the (minimum size) CBG that includes all NACKs is fed back.

[0238] Given a plurality of CBG configurations (e.g., (M,N) combinations) based on a tree structure such as method A-3, the terminal operates to select one specific CBG configuration, determine a CBG index including all NACKs based on the selected CBG configuration, and feed back the NACK CBG index and the selected CBG configuration information together to the base station. Here, it is preferable that one CBG having a minimum size while including all NACKs is selected as the NACK CBG. In other words, the terminal first operates to select a specific CBG configuration among the plurality of CBG configurations having a tree structure, which allows a single CBG to have a minimum size and include all NACKs, determine one CBG index including all NACKs based on the selected CBG configuration, and feed back this (together with the selected CBG configuration information) to the base station.

[0239] Similarly, when multiple CBG configurations (based on the size / number of different SGs ( / RBGs)) having a tree structure based on SGs (and / or RBGs) like method A-4 are given, it is also possible for the terminal to select one CBG configuration based on a specific SG ( / RBG), determine a CBG index including all NACKs based on the selected CBG configuration, and feed back the NACK CBG index and the selected CBG configuration (or the corresponding SB ( / RBG) configuration) information together to the base station.

[0240] Furthermore, the above method can also be applied to CBG scheduling from a base station. Specifically, in a state where multiple CBG configurations (e.g., M and / or N (combinations), or the size / number of SGs ( / RBGs)) having a tree structure such as method A-3 or A-4 are given, one CBG index based on one specific CBG configuration can be indicated through DL data scheduling DCI. In this case, the terminal performs (reception) operations under the assumption / regard that a CBG set belonging to the corresponding CBG index has been scheduled through the corresponding DCI.

[0241] 3) Method B-3: Maintaining the same CBG configuration and corresponding A / N configuration during one HARQ process

[0242] In order to prevent unnecessary RLC-level DL data retransmission due to an A / N error of a particular CBG, the CBG configuration (for retransmission (CBG) scheduling (indication) in the base station) and the A / N feedback configuration corresponding to the CBG configuration may be maintained the same while one HARQ process is being performed (i.e., until it is completed). Specifically, the CBG configuration and the corresponding A / N feedback configuration initially applied / indicated for DL ​​data scheduling / transmission having a particular HARQ process ID may be maintained the same until the corresponding HARQ process is completed (e.g., until decoding is successful for all CBs constituting the TB of DL data, or until new DL data scheduling (with NDI toggled) begins with the same HARQ process ID). Here, the initially applied / indicated CBG and A / N configuration information are indicated to the terminal through semi-static signaling (e.g., RRC signaling) or dynamic signaling (e.g., DCI, (initial) DL data scheduling DCI). If the CBG and A / N configuration information initially applied / indicated is indicated through semi-static signaling (e.g., RRC signaling), the CBG and A / N configuration information is semi-statically fixed and remains the same for all HARQ processes until there is new RRC signaling.

[0243] In addition, the terminal configures and feeds back an A / N bit for each CBG, and operates to feed back a NACK to the corresponding CBG until decoding is successful for each CBG (regardless of whether the corresponding CBG is scheduled or not), and from the point at which decoding is successful, operates to feed back an ACK to the corresponding CBG (regardless of whether the corresponding CBG is scheduled or not, and until the end of the corresponding HARQ process).

[0244] Figure 17 is a diagram illustrating signal transmission according to the present invention. Figure 17 assumes that the number of CBGs per TB is set to 3 and that the TB is (re)transmitted for the same HARQ process (i.e., assumes operation before the HARQ process corresponding to the TB is terminated).

[0245] Referring to FIG. 17, the terminal may receive CBG#0, #2 for a TB (e.g., HARQ process #a) from the base station (S1702). Here, the TB in step S1702 is an initial transmission or a retransmission corresponding to the HARQ process #a. Also, it is assumed that CBG#1 has not been successfully decoded before. In this case, the terminal transmits A / N information corresponding to three CBGs to the base station (S1704), sets the A / N information for CBG#1 to NACK, and sets the A / N information for CBG#0, #2 to ACK or NACK depending on the decoding result. Then, the base station retransmits the TB (e.g., HARQ process #a) in CBG units, and the terminal may receive CBG#1, #2 for the corresponding TB (S1706). In this case, the terminal transmits A / N information corresponding to the three CBGs to the base station (S1708), and since CBG#0 has previously been successfully decoded, the A / N information for CBG#0 is set to ACK, and the A / N information for CBG#1 and #2 is set to ACK or NACK depending on the decoding result.

[0246] 4) Method B-4: Set the corresponding A / N transmission time delay differently depending on the number of scheduled CB / CBGs.

[0247] Set the corresponding A / N transmission time delay (i.e., the time interval between A / N feedback transmissions corresponding to DL data reception) to be different according to the number of CBs or CBGs scheduled simultaneously for the same one TB (size). Specifically, the smaller the number of scheduled CBs or CBGs, the smaller the corresponding A / N delay is set. As an example, compared with the case where the entire TB, i.e., all CBs, are scheduled, the A / N delay corresponding to the case where some CBs or CBGs are scheduled is set to be much smaller. Also, assuming the same CBG size, the A / N delay corresponding to the case where a smaller number of CBGs are scheduled is set to be much smaller. Further, when the number of scheduled CBGs is the same, the A / N delay corresponding to the case where the CBG size is configured to be smaller is set to be much smaller.

[0248] 5) Method B-5: Set the CBG configuration (number / size of CBGs) to be different between DL data scheduling and A / N feedback

[0249] Set the configuration of the CBG (e.g., number / size of CBGs) applied to DL data scheduling / transmission and the configuration of the CBG applied to the A / N feedback corresponding to the reception of the corresponding DL data to be different. Here, the CBG configuration is indicated through the DL data scheduling DCI. Specifically, the (M,N) combinations for DL data scheduling and the (M,N) combinations for A / N feedback configuration are set to different values. As an example, the (M1,N1) combination is set for DL data scheduling and the (M2,N2) combination is set for A / N feedback respectively. Thus, when comparing Case 1 where M1>M2 (and N1<N2) and Case 2 where M1<M2 (and N1>N2), in Case 1, the number of bits of the DCI increases, while the data resources for retransmission DL and the number of bits of the A / N feedback decrease, and in Case 2, the number of bits of the DCI decreases, while the data resources for retransmission DL and the number of bits of the A / N feedback increase.

[0250] 6) Method B-6: For multiple scheduled CBGs, set the A / N transmission time delay differently for each CBG

[0251] For multiple CBGs scheduled simultaneously, the A / N transmission time delay is set differently for each CBG (i.e., the A / N is TDM-transmitted for each CBG). Specifically, the A / N delay corresponding to the CBG transmitted through a lower symbol (or slot) index is set to be smaller. As a result, the A / N corresponding to the CBG transmitted through a lower symbol (or slot) index can be fed back at a relatively faster symbol (or slot) timing.

[0252] 7) Method B-7: Configuring A / N feedback corresponding to (re)transmission scheduling per TB (composed of M CBGs)

[0253] The UE may be instructed through semi-static signaling (e.g., RRC signaling) or dynamic signaling (e.g., (initial) DL data scheduling DCI) whether to perform A / N feedback in one of the TB-based A / N bit configuration and the CBG-based A / N bit configuration. In the case of the CBG-based A / N bit configuration, the size of the A / N payload (and the PUCCH format for the corresponding A / N transmission) is set through semi-static signaling (e.g., RRC signaling). In this case, the total number of CBGs constituting the TB is determined according to a given (fixed) A / N payload size (e.g., M bits). For example, the number of CBGs is determined to be M, which is the same as the number of A / N bits. Thus, the number of CBGs constituting the TB is set to be the same for different TBSs, and the number of CBs constituting one CBG is set to be different (e.g., a value proportional to the TBS) depending on the TBS. In addition, when the number of all CBs constituting a TB is equal to or smaller than the size of a given A / N payload, feedback of the entire A / N is configured by allocating an A / N bit to each CB without grouping the CBs. On the other hand, when the number of all CBs N is smaller than the size M (bits) of a given A / N payload, an A / N bit is allocated to each CB, and 1) the remaining (MN) bits not allocated to the A / N for each CB are treated as NACK, or 2) the size of the A / N payload itself can be changed to N (bits), which is the same as the number of all CBs.

[0254] For each TBS, the number of CBs constituting the TB and the CBG configuration based thereon (e.g., the number M of all CBGs constituting the TB, the number N of CBs constituting a single CBG) are determined based on a predetermined rule. Also, the size of the A / N payload and the format of the corresponding PUCCH are set based on the number of CBGs set in the TB. For example, the PUCCH format and candidate PUCCH resource sets used for A / N transmission in CBG units are set independently (differently) for each TBS (thereby the number M of all CBGs). Also, the M value and / or the corresponding PUCCH format are indicated to the terminal through semi-static signaling (e.g., RRC signaling) or dynamic signaling (e.g., (DL data scheduling) DCI). As an example, a specific combination is indicated through DCI with a plurality of combinations (M value, PUCCH format (and candidate PUCCH resource set)) designated in advance, or the M value and the PUCCH format are indicated independently through RRC and / or DCI. In addition, when an M value is specified, a PUCCH format (and a candidate PUCCH resource set) for which the corresponding M value is pre-specified is automatically determined, or when a PUCCH format is specified, an M value pre-specified for the corresponding PUCCH format is automatically determined.

[0255] As another method, the N value and / or the corresponding PUCCH format are indicated to the terminal through quasi-static signaling (e.g., RRC signaling) or dynamic signaling (e.g., (DL data scheduling) DCI). As an example, a specific combination is indicated through DCI with a plurality of N values and a combination of a plurality of (M, PUCCH format (and candidate PUCCH resource sets)) specified in advance, or the N value and the PUCCH format can be indicated independently through RRC signaling and / or DCI. When the N value is indicated, the PUCCH format (and candidate PUCCH resource set) specified for the M value thereby is automatically determined, or when the PUCCH format is indicated, the number of overall CBGs and the number of CBs per CBG are automatically determined based on the size of the A / N payload (e.g., M bits) thereby.

[0256] 8) Method B-8: Configure the A / N feedback corresponding to the (re)transmission of some CBGs (among the M CBGs constituting the TB)

[0257] When performing (re)transmission scheduling for L or less CBGs (L < M) among the overall M CBGs constituting the TB, the following method can be considered.

[0258] For Opt 1), the same A / N payload size (e.g., M bits) as in the case of A / N feedback corresponding to (re)transmission of TB units (such as in Method B-7) is applied. Thus, actually A / N is mapped only to L bits corresponding to (retransmission-scheduled CBGs), and the other (M - L) bits corresponding to (non-scheduled CBGs) are mapped to ACK or NACK according to the success / failure of decoding of the corresponding CBGs (similar to Method B-3), or are treated as NACK. For Opt 2), a different (e.g., smaller) A / N payload size (and PUCCH format) corresponding to (re)transmission of TB units can be applied. In the case of Opt 2, the A / N payload size (and PUCCH format) can be changed according to the number L of scheduled CBGs. As an example, the A / N payload can be composed of only L bits.

[0259] Here, L is quasi-fixed to one value through quasi-static signaling (e.g., RRC signaling), or can be dynamically changed through dynamic signaling (e.g., DL data scheduling DCI). In the former case, corresponding CBG indication signaling is configured so that scheduling can be performed for up to L out of the total M CBGs through CBG unit scheduling DCI. Further, retransmission scheduling (from the base station) is performed only for L or less CBGs out of the total M CBGs constituting the TB (L < M). In this case, when the number of CBGs to be scheduled exceeds L, the base station / terminal can perform TB unit scheduling (DCI transmission) / A / N feedback.

[0260] Note that Opt 1 and 2 can be applied on the assumption that the CBG configuration (e.g., the total number M of CBGs constituting the TB, the number N of CBs constituting a unit CBG) first applied / indicated for TB scheduling / transmission is maintained the same during the HARQ process.

[0261] Furthermore, in the case of Opt 1, the size of the A / N payload is set based on (re)transmission in TB units (e.g., M bits), and in order to configure A / N feedback only for the CBG that is actually scheduled, a number of CBs belonging to all scheduled L CBGs (each consisting of N CBs) are reconfigured into M CBGs (consisting of CBs less than N), and based on this, feedback of the entire A / N is configured by allocating A / N bits in CBG units. In this case, the base station can also perform retransmission scheduling by assuming that the M CBGs corresponding to the A / N feedback are a total CBG set. In addition, in a situation where a CB regrouping process is involved in a terminal corresponding to a DL data receiving end or an A / N transmitting end, if a NACK-to-ACK error occurs, a mismatch (and thus performance degradation) between the terminal and the base station regarding the CBG configuration may occur. Considering this problem, in addition to the A / N information for each of M CBGs, the overall A / N feedback (payload) can be configured to include an indicator (e.g., 1 bit) for indicating NACK feedback (presence or absence) for each TB or a retransmission request for the entire TB (presence or absence). In this way, when a mismatch occurs in the CBG configuration, the terminal can map / transmit the corresponding indicator to a state corresponding to "TB-based NACK" or "TB retransmission request". The base station receiving this can again perform TB scheduling based on the initial CBG configuration before regrouping.

[0262] On the other hand, in the case of a retransmission scheduling DCI for a CBG corresponding to A / N feedback in Opt 2, the corresponding signaling is configured in either 1) a retransmission CBG indication form based on the total number M of CBGs regardless of changes in the size of the A / N payload, or 2) a CBG indication form in a state in which the CBG set (M or less) that the UE has fed back to the NACK is assumed to be the total CBG configuration.

[0263] Furthermore, it is also possible to indicate to the terminal through semi-static signaling (e.g., RRC signaling) or dynamic signaling (e.g., (DL data scheduling) DCI) whether to always apply (fixed) the same A / N payload size (and PUCCH format) regardless of the number of CBGs scheduled like Opt1 for CBG (retransmission) scheduling, or to dynamically change and apply the A / N payload size (and PUCCH format) based on the number of CBGs scheduled like Opt2.

[0264] 9) Method B-9: A / N feedback in CBG units only when some of the M CBGs (constituting the TB) are NACK

[0265] Among the total M CBGs constituting the TB, A / N feedback in CBG units can be configured / transmitted only when the number of CBGs that are NACK is L (L < M) or less (e.g., individually allocating A / N bits for each CBG). When the number of CBGs that are NACK exceeds L, it operates to configure / transmit A / N feedback in TB units. In this case, since A / N feedback in CBG units is configured only for L or fewer NACKs, the retransmission CBG (index) indication through the CBG unit (retransmission) scheduling DCI corresponds to 1) an indication form for L or fewer CBGs among the total M, or 2) a signaling form of CBG indication assuming the set of CBGs (L or fewer) for which the terminal has fed back NACK as the entire CBG configuration. For example, when i = {1,..., L}, for all i values, all combinations of selecting i CBGs out of the total M CBGs are indexed, and the terminal can feedback one of the corresponding indexes to the base station to indicate the set of CBGs that are NACK.

[0266] 10) Method B-10: CBG retransmission scheduling and A / N feedback in a form where the maximum number of CBGs is limited to M

[0267] From the viewpoint of base station scheduling, the entire CBG configuration is configured with Mr CBGs (Mr≦M), among which, the UE can be instructed to perform retransmission for L CBGs (L≦Mr). Here, M has a fixed value during at least one TB transmission or one HARQ process, while Mr (and L) can be changed at each (retransmission) scheduling time.

[0268] In this case, the terminal may behave as follows in terms of A / N feedback:

[0269] Opt 1) Configure A / N feedback based on the maximum possible number of CBGs, M. For example, configure the size of the entire A / N payload to be M bits, and process (ML) bits corresponding to CBGs that are not actually scheduled as NACK or DTX.

[0270] Opt 2) Configure A / N feedback based on the total number of CBGs Mr at the time of scheduling. For example, configure the size of the total A / N payload to Mr bits, and process (Mr-L) bits corresponding to CBGs that are not actually scheduled as NACK or DTX.

[0271] Opt 3) Configure A / N feedback based on the number of scheduled CBGs, L. For example, configure the size of the total A / N payload to be L bits, and map / transmit an A / N bit for each scheduled CBG.

[0272] In the case of Opt 2 / 3, the size of the A / N payload can be changed according to the Mr value or the L value, and thus the PUCCH format (and the candidate PUCCH resource set) used for A / N feedback transmission can also be changed.

[0273] In this case, the total Mr CBG configuration for retransmission scheduling in the base station can be configured for the entire CB set constituting the TB (i.e., the entire CBG set is the same as the entire TB) or can be configured only for a specific part of the entire CB (i.e., the entire CBG set corresponds to a part of the TB). In the former case, the Mr value at a specific scheduling point for one TB transmission or one HARQ process is limited to be set to only a value that is always smaller or equal to the Mr value at the previous scheduling point. In the latter case, the specific part of CBs means 1) a CB set belonging to L CBGs scheduled at the previous scheduling point, or 2) a CB set belonging to a CBG fed back from the terminal in the NACK among the L scheduled CBGs.

[0274] 11) Method B-11: Processing for subsequent CBGs scheduled for retransmission before A / N feedback transmission

[0275] A situation may occur where a retransmission of a CBG (hereinafter, subsequent CBG) for a specific TB (hereinafter, original TB) is scheduled before the transmission of an A / N feedback (hereinafter, first A / N) corresponding to the reception of the same TB. In this case, it may be impossible to transmit an A / N feedback reflecting the reception combining for the subsequent CBG at the time of the first A / N because the end time of the decoding for the subsequent CBG is too late. Here, reception combining refers to the operation of storing the subsequent CBG after emptying (flushing) the buffer in which the previously received signal was stored. In this case, the terminal can 1) transmit A / N feedback based on the decoding result only for the original TB at the first A / N point, and perform reception synthesis for the subsequent CBGs (for A / N feedback at a later point), or 2) transmit A / N feedback based on the decoding result reflecting reception synthesis of the subsequent CBGs at a point a certain delay later than the first A / N point. In the case of 2), the A / N transmission at the first A / N point can be omitted, or only the A / N for the original TB can be transmitted.

[0276] In addition, in the UL data scheduling situation, a (subsequent) CBG retransmission for the same TB can be scheduled at a time before the transmission of a specific (or initial) TB. Here, the transmission time of the original TB (hereinafter, TX timing 1) and the transmission time of the subsequent CBG (hereinafter, TX timing 2) are different from each other, and TX timing 2 can be indicated to be later than TX timing 1. In this case, the UE transmits only other signals (e.g., punctured for RE / RB / symbol to which the corresponding CBG is mapped) among the scheduled original TB signals through TX timing 1, except for the CBG corresponding to the subsequent CBG, and can transmit the subsequent CBG scheduled for retransmission as it is through TX timing 2.

[0277] Similarly, in the case of cross-slot scheduling for DL ​​data, a (subsequent) CBG retransmission for the same TB can be scheduled at a time before the reception of a specific (or initial) TB. Here, the reception time of the original TB (hereinafter, TX timing 1) and the reception time of the subsequent CBG (hereinafter, TX timing 2) can be different from each other, and TX timing 2 can be indicated to be later than TX timing 1. In this case, the UE can receive only other signals except for the CBG corresponding to the subsequent CBG (e.g., punctured for the RE / RB / symbol to which the corresponding CBG is mapped) among the scheduled original TB signals through TX timing 1, and can receive the subsequent CBG scheduled for retransmission as it is through TX timing 2.

[0278] (C) How SoftBuffer operates

[0279] 1) Method C-1: Determine the minimum buffer size per CB based on the total number of CBs belonging to the CBG that is NACKed.

[0280] A method can be considered in which the (minimum) buffer size Bc per TB allocated to one HARQ process or one TB is divided by the total number Cn of CBs belonging to (multiple) CBGs fed back by the terminal in a NACK (to the base station) to determine the minimum buffer size per CB from the terminal reception perspective (e.g., Bc=Bt / Cn). Specifically, it is possible to replace C in Equation 4 with Cn as shown in the following equation. Here, the minimum buffer size per CB means, for example, the minimum number of (soft channel) bits that the terminal should buffer for each CB for TB transmission.

[0281] [Formula 5] JPEG0007601844000016.jpg19117

[0282] In this case, compared to the existing method based on A / N feedback in TB units, there is an advantage that the minimum buffer size per CB increases (e.g., because C>Cn). In addition, Cn applied to one HARQ process or one TB transmission can be determined 1) based only on the first A / N feedback (among which the CBG is NACK) configured in CBG units (i.e., Cn is applied in the same manner until the end of the HARQ process), or 2) based on the A / N feedback (among which the CBG is NACK) at each time point for each A / N transmission time point (i.e., Cn is determined by the NACK CBG at each scheduling / feedback time point).

[0283] In addition, a method of applying Cn of method C-2 to equation 5 (i.e., the total number of CBs belonging to (multiple) CBGs that have been fed back as NACK or require retransmission (or failed to receive ACK feedback) from the base station's perspective) can also be considered.

[0284] 2) Method C-2: Rate matching operation (limited / circular buffer) in the base station for retransmitted CBG signals

[0285] When performing (limited / circular buffer) rate matching based on all CBGs fed back to the NACK (from the UE) or requiring retransmission from the BS's perspective, a mismatch may occur between the NACK CBG from the BS's perspective and the NACK CBG fed back by the UE due to an A / N error. To eliminate such a mismatch, the following operations can be considered.

[0286] 1) The base station always operates to perform retransmission scheduling for all CBGs that have been fed back (from the terminal) in a NACK (or for which ACK feedback has not been received) together / simultaneously (i.e., the base station does not allow retransmission scheduling for only some NACK CBGs) (the terminal operates under this assumption / regard), or

[0287] 2) (Although the base station is allowed to schedule retransmission for only a portion of the entire NACK CBGs) From the base station's perspective, information on all CBGs that have been fed back to the NACK or require retransmission (or for which ACK feedback could not be received) (e.g., the number / index of NACK CBGs) can be indicated to the terminal via DL data scheduling DCI.

[0288] In this case, the (minimum) buffer size Bt per TB allocated to one HARQ process or one TB can be divided by the total number Cn of CBs belonging to (multiple) CBGs that have been fed back as NACK or require retransmission (or have failed to receive ACK feedback) from the base station's perspective to determine the minimum buffer size per CB from the base station's transmission perspective (e.g., Bc=Bt / Cn). Specifically, it is possible to replace C in Equation 2 with Cn as shown in the following equation.

[0289] [Formula 6] JPEG0007601844000017.jpg2253

[0290] Even in this case, compared to the existing method that applies only TB-based retransmission, there is an advantage that the minimum buffer size per CB increases (e.g., because C>Cn). Cn applied to one TB transmission can be 1) determined based on the retransmission time point of the first CBG unit (i.e., Cn is applied the same until the end of the HARQ process), or 2) determined for each CBG unit retransmission time point (i.e., Cn is determined based on the number of CBGs that have been fed back as NACK or require retransmission (or could not be fed back as ACK) based on each time point).

[0291] In addition, when indication information for a CBG index to be (re)transmitted and buffer flush indication information for each CBG are signaled through the data scheduling DCI, signaling of buffer flush indication information may not be necessary for a CBG index without a (re)transmission indication. Here, the buffer flush information includes information on whether to flush and empty a corresponding buffer before storing a received CBG signal in the buffer, or to combine the corresponding CBG signal with an already stored CBG signal without emptying it. When an instruction is given to flush and empty a buffer for a CBG index without a (re)transmission indication (or conversely, an instruction is given to combine the buffer without emptying it), the terminal may operate in a state in which the corresponding CBG index is regarded / assumed to be a CBG for which ACK feedback has been received or for which retransmission is not required from the viewpoint of the base station. Conversely, when an instruction is given to combine the buffer without emptying it (or conversely, an instruction is given to flush and empty the buffer), the terminal does not perform any operation for the corresponding CBG index (corresponding reception buffer).

[0292] 3) Method C-3: Power offset application to A / N feedback PUCCH transmission by CBG-based scheduling

[0293] The power offset added / applied to PUCCH transmission carrying A / N feedback configured in CBG units can be determined to be a value proportional to the value of Opt 1 / 2 / 3 / 4 / 5 / 6 / 7. Thus, the larger the number of CBGs in Opt 1 / 2 / 3 / 4 / 5 / 6 / 7, the larger the corresponding power offset can be added / applied.

[0294] Opt 1) The total number of CBGs to which A / N bits are assigned or for which A / N feedback is targeted (without distinction between A / Ns)

[0295] Opt 2) Number of CBGs scheduled by the base station

[0296] Opt 3) Number of NACK CBGs (at the base station) instructed by the base station in method C-2

[0297] Opt 4) Number of NACK CBGs at the terminal

[0298] Opt 5) Considering the A / N feedback configuration method such as method B-3, the sum of the number of CBGs in Opt 2 and the number of CBGs that were not scheduled but fed back ACK

[0299] Opt 6) The sum of the number of CBGs in Opt 3 and the number of CBGs that were not scheduled but fed back to the ACK

[0300] Opt 7) The number of other CBGs excluding the CBGs that have already fed back the power offset to the ACK at a point before the corresponding timing to be added / applied to the A / N PUCCH transmission through a specific timing

[0301] (D) Mismatch handling method

[0302] 1) Method D-1: Mismatch between A / N information for each CBG fed back by the terminal and CBG scheduled for retransmission by the base station

[0303] A mismatch (due to an A / N error) may occur between the A / N information for each CBG fed back by the terminal and the CBG index scheduled for retransmission by the base station corresponding to the A / N information. For example, the CBG index scheduled by the base station may not include / does not include some of the CBGs fed back by the terminal in the NACK, but may include the CBGs previously fed back in the ACK. In this case, the terminal is configured to perform the following operations.

[0304] Opt 1) For scheduled CBGs that have previously been fed back to NACK, map the decoded A / N result after synthesis, or

[0305] Opt 2) For scheduled CBGs that have previously been fed back to the ACK, either map the ACK again (without synthesis / decoding) (see method B-3),

[0306] Opt 3) Map NACKs to all CBGs, or

[0307] Opt 4) NACK feedback per TB or request retransmission of the entire TB, or

[0308] Opt 5) It is possible to operate to discard the corresponding CBG scheduling DCI.

[0309] In addition, if the scheduled CBG includes all CBGs previously fed back to the NACK, one of Opt 1 / 2 is applied, and if not, one of Opt 3 / 4 / 5 can be applied.

[0310] 2) Method D-2: Discrepancy between CRCs applied to the whole TB and CRCs applied per CB and / or CBG

[0311] The check result (e.g., success / failure) of the received CRC in the terminal may be different between the CRC applied to the entire TB, the CRC applied to the CB unit, and the CRC applied to the CBG unit. Here, if the CRC check result is success (pass), it means that the corresponding data block has been successfully / correctly detected, and if the CRC check result is failure (fail), it means that the corresponding data block has not been successfully / correctly detected.

[0312] As an example, the CRC check results of the CB and / or CBG may all be successful (i.e., the CB CRC-based CRC check is successful), while the CRC check result of the entire TB may be a failure (i.e., the TB CRC-based CRC check is failed). Conversely, the CRC check result of at least one CB and / or CBG may be a failure (i.e., the CB CRC-based CRC check is failed), while the CRC check result of the entire TB may be successful (i.e., the TB CRC-based CRC check is successful). In this case, the terminal may apply any one of Opt 3 / 4 / 5 of method D-1. Opt 3 / 4 / 5 of method D-1 are as follows.

[0313] Opt 3) Map NACKs to all CBGs, or

[0314] Opt 4) NACK feedback per TB or request retransmission of the entire TB, or

[0315] Opt 5) The corresponding CBG scheduling DCI can be discarded.

[0316] As another example, the CRC check results of all CBs belonging to a specific CBG may be successful, but the CRC check result of the entire CBG may be a failure. Conversely, the CRC check result of at least one CB belonging to a specific CBG may be a failure, but the CRC check result of the entire CBG may be successful. In this case, the UE may map the CRC check result to a NACK for the corresponding CBG and feed it back, or may apply any of the methods of Opt 3 / 4 / 5 of method D-1.

[0317] (E)CBG Scheduling DCI Configuration

[0318] 1) Method E-1: Configuration and setting of RV in CBG-based scheduling (DCI)

[0319] In a CBG-based (retransmission) scheduling DCI, the RV field can be configured either 1) as a single field with the same size as the RV field of the TB-based scheduling DCI, and the indicated RV value can be applied uniformly to the entire scheduled CBG (in this case, the types of RV values ​​are configured to be the same as in the case of TB-based scheduling), or 2) as a single RV field for each CBG, and the size of each can be configured to be smaller than the RV field of the TB-based scheduling DCI (however, the types of RV values ​​are configured to be fewer than in the case of TB-based scheduling).

[0320] 2) Method E-2: Scheduling retransmission for some CBGs (among M CBGs constituting the TB)

[0321] Among the total of M CBGs that make up a TB, it operates so that retransmission scheduling can be performed only for up to the maximum L CBGs (L < M). Here, L is indicated to the terminal as one value through quasi-static signaling (for example, RRC signaling). As a result, through the scheduling DCI in units of CBGs from the base station, up to the maximum L CBGs out of the total M CBGs are indicated, and for retransmission scheduling for CBGs exceeding L, TB unit scheduling DCI (or a flag indicating (re)transmission scheduling in units of TBs within the DCI) is applied. Specifically, when i = {1,..., L}, all combinations of selecting i CBGs out of the total M CBGs are indexed, and a CBG set / combination corresponding to one of the corresponding indexes is considered to be indicated to the terminal through the CBG retransmission scheduling DCI.

[0322] 3) Method E-3: Use of the NDI field in CBG unit scheduling (DCI)

[0323] The NDI field can be interpreted differently depending on whether it is a (re)transmission of the entire TB or a retransmission of some CBGs (of all CBGs constituting the TB). As an example, the DCI can operate to recognize the combination of all CBGs constituting the TB being indicated to be transmitted and the NDI bit being toggled as a scheduling for new data transmission. Thus, the case in which only a part of the entire CBG is indicated to be transmitted through the DCI is regarded as a retransmission (not new data), and the NDI field can be used for other specific purposes. As another example, an indicator indicating whether the transmission is for the entire TB or for some CBGs can be directly signaled through the DCI. In this case, the transmission of the entire TB is indicated and the combination of the NDI bit being toggled can be recognized as a scheduling for new data transmission. Thus, the latter case (i.e., an indication of transmission of some CBGs) is regarded as a retransmission, and the NDI field can be used for other specific purposes. In addition, when the NDI field is used for other specific purposes, the NDI field can 1) indicate whether the received CBG signal should be combined with a previously stored signal in the receiving buffer corresponding to the corresponding CBG index and stored, or whether the previously stored signal should be flushed and emptied and only the received CBG signal should be newly stored (i.e., CBG buffer flush indicator, CBGFI), or 2) indicate the CBG (index) to be (re)transmitted (i.e., CBG transmission indicator, CBGTI).

[0324] 4) Method E-4: Use of the Buffer Flush Indicator Field in CBG-Based Scheduling (DCI)

[0325] The buffer flush indicator field can be interpreted differently in the case of data retransmission (without NDI toggling) and the case of new data transmission (with NDI toggling). For example, in the case of data retransmission, the buffer flush indicator can be used to indicate whether to flush and empty the corresponding buffer before storing the received CBG signal in the buffer (for each CBG) as per the original purpose of the buffer flush indicator, or to combine without emptying. In addition, in the case of new data transmission, since a buffer flush operation is basically assumed before storing the received signal, the buffer flush indicator can be used for other specific purposes. When the buffer flush indicator field is used for other specific purposes, it can include bits indicating TBS and / or MCS information of the scheduled data. Conversely, the TBS / MCS field includes TBS / MCS information in the DCI scheduling the transmission of new data, but includes bits constituting a buffer flush indicator in the DCI scheduling the data retransmission.

[0326] 5) Method E-5: Use of the CBGTI (and CBGFI) field in CBG-based scheduling (DCI)

[0327] A buffer flush for a specific CBG (set) can be indicated based on a value indicated through the CBGTI field in the DCI (or a combination of this and the value indicated through the CBGTI field). First, each bit constituting the CBGTI field is used to indicate whether or not to (re)transmit for each CBG index. For example, bit “1” can indicate that the CBG (corresponding to the corresponding bit) is (re)transmitted, and bit “0” can indicate that the corresponding CBG is not (re)transmitted. In addition, the CBGFI field / bit is used to indicate whether or not to flush the buffer for the CBG indicated for (re)transmission through the CBGTI field. For example, bit “1” can indicate that the buffer (for the CBG indicated for (re)transmission) is to be flushed, and bit “0” can indicate that the corresponding buffer is not to be flushed.

[0328] First, when only the CBGTI field is configured / set in the DCI (without configuring a specific CBGFI field) (hereinafter, CBG mode 1), all bits constituting the corresponding CBGTI field can be indicated as "0" (without toggling the NDI). In this case, the terminal can specify / consider that a (re)transmission for all CBGs constituting a given TB is indicated and at the same time a buffer flush operation for all CBGs is indicated. As a result, the terminal operates to flush the previously buffered signal and then buffer the newly received CBG signal. In addition, in CBG mode 1, all bits constituting the CBGTI field can be indicated as "1" (without toggling the NDI). In this case, the terminal can specify / consider that a (re)transmission for all CBGs constituting a given TB is indicated without a buffer flush operation being indicated.

[0329] Next, when both the CBGTI field and the CBGFI field are configured / set in the DCI (hereinafter, CBG mode 2), all bits constituting the CBGTI field can be indicated as “0” (NDI is not toggled). In this case, (the terminal) can specify / consider that (re)transmission is indicated for all CBGs constituting a given TB. Furthermore, in this state, in case 1) when the CBGFI bit is indicated as “0”, (the terminal) can specify / consider that a buffer flush operation is indicated for a specific part of CBGs (hereinafter, CBG sub-group 1), and in case 2) when the CBGFI bit is indicated as “1”, (the terminal) can specify / consider that a buffer flush operation is indicated for another specific part of CBGs (hereinafter, CBG sub-group 2). (Multiple) CBGs belonging to CBG sub-group 1 and CBG sub-group 2 can be configured to be completely exclusive of each other (while the union of the corresponding CBGs is the set of all CBGs) or can be configured to be partially identical. In addition, in CBG mode 2, when all bits constituting the CBGTI field are indicated as "1" (with NDI not being toggled) and the CBGFI bit is indicated as "1" (or "0"), (the terminal) can specify / consider that (re)transmission for all CBGs constituting a given TB is indicated and at the same time buffer flush operation for all CBGs is indicated (or not indicated).

[0330] On the other hand, taking into consideration early termination of TB decoding operations at the terminal, 1) for multiple CBGs, CBs are decoded one by one in turn for each CBG (for example, decoding is performed in the order of CB1 in CBG-1 => CB1 in CBG-2 => ... CB1 in CBG-M => CB2 in CBG-1 => ...), or 2) decoding is performed in order (on the index) for each CBG (for example, decoding is performed in the order of CBs in CBG-1 => CBs in CBG-2 => ...), and when a CBG that is a NACK occurs, a NACK can be fed back for all subsequent CBGs (by omitting the decoding operation).

[0331] In addition, the retransmission scheduling in units of CBG and the configuration operation of A / N feedback for each CBG may not be applied / set for DL / UL data transmitted based on the SPS scheme. Thus, the retransmission scheduling in units of CBG and the configuration operation of A / N feedback for each CBG may be set / applied only for DL / UL data transmission based on general scheduling other than the SPS scheme, and the scheduling in units of TB and the A / N feedback for each TB (i.e., TB level) (e.g., configuring / transmitting 1-bit A / N for one TB) may be applied / set for SPS-based DL / UL data transmission. In addition, the retransmission scheduling in units of CBG and the configuration operation of A / N feedback for each CBG may not be applied / set for DL / UL data scheduled through terminal (group) CSS-based DCI (or a specific DCI format, for example, a TM common DCI format similar to DCI format 0 / 1A in LTE (set / used in common for different TMs)) transmission (and / or Msg3 scheduled from RAR accompanying a random access process and Msg4 transmitted for the purpose of contention resolution). As a result, retransmission scheduling on a CBG basis and configuration of A / N feedback for each CBG can be applied / configured only for DL / UL data transmission scheduled through non-CSS USS-based DCI (or TM-specific DCI format set / used only for a specific TM) transmission. On the other hand, scheduling on a TB basis and A / N feedback for each TB (TB level) can be applied / configured (i.e., TB-level A / N feedback is configured) for DL / UL data (and / or Msg3 / 4) transmission scheduled through CSS-based DCI (or TM-common DCI format) transmission.

[0332] In addition, in a situation where retransmission scheduling in units of CBGs and configuration operation of A / N feedback for each CBG are set, if TB-level A / N feedback is configured for the above reasons (or for other reasons, for example, the terminal bundles A / Ns for each CBG to reduce the A / N payload, or the A / N bundling operation is instructed by the base station), the A / N method changes depending on whether (Case 1) only the A / N for a single TB is transmitted without multiplexing, or (Case 2) multiple A / Ns for multiple TBs are multiplexed and transmitted. For example, in Case 1, after configuring only a 1-bit A / N payload, the A / N is transmitted using a PUCCH format / resource supporting a small payload (e.g., up to 2 bits). On the other hand, in Case 2, when the number of CBGs per TB is set to N, Opt 1) the A / N for the TB can be repeatedly mapped to the corresponding N bits in the same manner, or Opt 2) the A / N for the TB can be mapped to 1 bit corresponding to a specific (e.g., lowest) CBG index. On the other hand, Opt1 and Opt2 are applied regardless of Case 2 in a situation where retransmission scheduling per CBG and configuration operation of A / N feedback per CBG are configured.

[0333] In case 2, the UE may configure a multi-bit A / N payload including an N-bit A / N corresponding to a corresponding TB and transmit the A / N using the multi-bit A / N payload as a PUCCH format / resource supporting a large payload (e.g., 3 bits or more). The multi-bit A / N payload includes A / N information corresponding to multiple TBs. As an example, the multi-bit A / N payload may include multiple N-bit A / Ns corresponding to multiple TBs.

[0334] In addition, when considering a situation where the above-mentioned intentional URLLC puncturing operation is applied in a co-channel inter-cell environment, it is preferable to minimize the interference effect of at least a URLLC signal transmitted in a specific cell on a DMRS signal used for DL / UL data reception in another cell. For this purpose, an operation of transmitting / exchanging position information of symbols used for DMRS transmission in each cell and / or position information of symbols used for URLLC (puncturing) transmission in each cell between cells can be considered.

[0335] The proposed method of the present invention is not limited to the situation of DL data scheduling and transmission, but can be applied in the same / similar manner to the situation of UL data scheduling and transmission (e.g., CB / CBG configuration by TB, UL data transmission timing setting, DCI configuration of CBG scheduling, etc.). In this regard, in the proposed method of the present invention, DL data (scheduling DCI) can be replaced with UL data (scheduling DCI).

[0336] FIG. 18 illustrates a base station and a terminal applicable to an embodiment of the present invention.

[0337] 18, the wireless communication system includes a base station (BS) 110 and a terminal (UE) 120. In the case of a system including a relay, the base station or the terminal can be replaced by the relay.

[0338] The base station 110 includes a processor 112, a memory 114, and a radio frequency (RF) unit 116. The processor 112 may be configured to implement the process and / or method proposed in the present invention. The memory 114 is coupled to the processor 112 and stores various information related to the operation of the processor 112. The RF unit 116 is coupled to the processor 112 and transmits and / or receives wireless signals. The terminal 120 includes a processor 122, a memory 124, and an RF unit 126. The processor 122 may be configured to implement the process and / or method proposed in the present invention. The memory 124 is coupled to the processor 122 and stores various information related to the operation of the processor 122. The RF unit 126 is coupled to the processor 122 and transmits and / or receives wireless signals.

[0339] 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.

[0340] In this document, the embodiment of the present invention has been described mainly with respect to the data transmission and reception relationship between a terminal and a base station. In this document, a specific operation described as being performed by a base station may be performed by its upper node in some cases. That is, it is clear that various operations performed for communication with a terminal in a network consisting of a plurality of network nodes including a base station may be performed by a base station or other network nodes other than a base station. A base station may be replaced with terms such as a fixed station, Node B, eNodeB (eNB), access point, etc. Also, a terminal may be replaced with terms such as a UE (User Equipment), MS (Mobile Station), MSS (Mobile Subscriber Station), etc.

[0341] Embodiments of the present invention may be implemented by various means, such as hardware, firmware, software, or a combination thereof. In a hardware implementation, an embodiment of the present invention may be implemented by one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, etc.

[0342] In the case of a firmware or software implementation, an embodiment of the present invention may be implemented in the form of a module, procedure, function, etc. performing the above-mentioned functions or operations. The software code may be stored in a memory unit and executed by a processor. The memory unit may be located inside or outside the processor and may exchange data with the processor by various means known in the art.

[0343] 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]

[0344] 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 to transmit HARQ-ACK information based on a code block group (CBG), each of which is an individual group of a plurality of code blocks (CBs), comprising: receiving a first transport block (TB) including a plurality of CBGs during a first HARQ process, the plurality of CBGs including a CBG having a first number of CBs and a CBG having a second number of CBs based on a total number of CBs in the first TB being greater than a value set via higher layer signaling; transmitting a first HARQ-ACK response including an ACK for each of at least one first CBG that was correctly decoded in the first TB and a NACK for each of at least one second CBG that was not correctly decoded in the first TB; receiving a second TB including the at least one second CBG as a CBG-based retransmission of the first TB during the first HARQ process; In response to receiving the second TB, transmitting a second HARQ-ACK response including (i) an ACK / NACK for each of the at least one second CBG according to a result of decoding the second TB, and (ii) an ACK for each of the at least one first CBG that was correctly decoded in the first TB; Including, The method, wherein the terminal reports an ACK for the at least one first CBG based on the at least one first CBG being correctly decoded once in the first TB for the first HARQ process.

2. The method of claim 1, wherein an ACK is reported for the at least one first CBG based on the at least one first CBG being correctly decoded once in the first TB, regardless of rescheduling of each of the at least one first CBG.

3. A computer-readable storage medium storing instructions that, when executed by a processor of a terminal, cause the terminal to perform the method of claim 1.

4. An apparatus configured to transmit HARQ-ACK information on a code block group (CBG) basis, each CBG being a separate group of a plurality of code blocks (CBs), At least one processor; at least one computer memory operably connected to the at least one processor; The at least one computer memory, when executed, causes the at least one processor to: receiving a first transport block (TB) including a plurality of CBGs during a first HARQ process, and based on a total number of CBs in the first TB being greater than a value set via higher layer signaling, the plurality of CBGs include a CBG having a first number of CBs and a CBG having a second number of CBs; Transmitting a first HARQ-ACK response including an ACK for each of at least one first CBG that was correctly decoded in the first TB and a NACK for each of at least one second CBG that was not correctly decoded in the first TB; receiving a second TB including the at least one second CBG as a CBG-based retransmission of the first TB during the first HARQ process; storing instructions to perform operations including, in response to receiving the second TB, transmitting a second HARQ-ACK response including (i) an ACK / NACK for each of the at least one second CBG in response to a result of decoding the second TB, and (ii) an ACK for each of the at least one first CBG that was correctly decoded in the first TB; The apparatus, wherein an ACK is reported for the at least one first CBG based on the at least one first CBG being correctly decoded once in the first TB for the first HARQ process.

5. The apparatus of claim 4, wherein an ACK is reported for the at least one first CBG based on the at least one first CBG being correctly decoded once in the first TB, regardless of rescheduling of each of the at least one first CBG.

6. further comprising at least one transceiver; The apparatus of claim 4 , wherein the apparatus is a terminal in a wireless communication system.

7. The apparatus of claim 4 , wherein the apparatus is an ASIC or a digital signal processing device configured to control a terminal in a wireless communication system.

8. A method for receiving HARQ-ACK information on a code block group (CBG) basis, each of which is a separate group of a plurality of code blocks (CBs), by a base station, comprising: transmitting a first transport block (TB) including a plurality of CBGs during a first HARQ process, the plurality of CBGs including a CBG having a first number of CBs and a CBG having a second number of CBs based on a total number of CBs in the first TB being greater than a value set via higher layer signaling; receiving a first HARQ-ACK response including an ACK for each of at least one first CBG of the first TB and a NACK for each of at least one second CBG of the first TB; determining, based on the first HARQ-ACK response, that the at least one first CBG, indicated as an ACK, was correctly transmitted and that the at least one second CBG, indicated as a NACK, was not correctly transmitted; transmitting a second TB including the at least one second CBG as a CBG-based retransmission of the first TB during the first HARQ process; In response to transmitting the second TB, (i) receiving an ACK / NACK for each of the at least one second CBG according to a result of the CBG-based retransmission, and (ii) receiving a second HARQ-ACK response including an ACK for each of the at least one first CBG indicated as an ACK by the first HARQ-ACK response. Including, A method in which an ACK is received by the base station for the at least one first CBG based on the at least one first CBG being successfully transmitted once through the first TB for the first HARQ process.

9. The method of claim 8, wherein an ACK is received by the base station for the at least one first CBG until the end of the first HARQ process based on the at least one first CBG being correctly transmitted once through the first TB.

10. A computer-readable storage medium storing instructions that, when executed by a processor of a base station, cause the base station to perform the method of claim 8.

11. A base station configured to receive HARQ-ACK information on a code block group (CBG) basis, each CBG being a separate group of a plurality of code blocks (CBs), at least one memory configured to store instructions; at least one processor; The at least one processor executes the instructions to: During a first HARQ process, transmit a first transport block (TB) including a plurality of CBGs, and based on a total number of CBs in the first TB being greater than a value set via higher layer signaling, the plurality of CBGs include a CBG having a first number of CBs and a CBG having a second number of CBs; receiving a first HARQ-ACK response including an ACK for each of the at least one first CBG of the first TB and a NACK for each of the at least one second CBG of the first TB; determining, based on the first HARQ-ACK response, that the at least one first CBG, indicated as an ACK, was correctly transmitted and that the at least one second CBG, indicated as a NACK, was not correctly transmitted; transmitting a second TB including the at least one second CBG as a CBG-based retransmission of the first TB during a first HARQ process; In response to transmitting the second TB, the method is configured to perform operations including: (i) receiving an ACK / NACK for each of the at least one second CBG in response to a result of the CBG-based retransmission; and (ii) receiving a second HARQ-ACK response including an ACK for each of the at least one first CBG indicated as an ACK by the first HARQ-ACK response; A base station, wherein an ACK is received by the base station for the at least one first CBG based on the at least one first CBG being correctly transmitted once through the first TB for the first HARQ process.

12. The base station of claim 11, wherein an ACK is received by the base station for the at least one first CBG until the end of the first HARQ process based on the at least one first CBG being correctly transmitted once through the first TB.

13. A method for a terminal to transmit HARQ-ACK information based on a code block group (CBG), each of which is an individual group of a plurality of code blocks (CBs), comprising: receiving a first transport block (TB) including a plurality of CBGs during a first HARQ process, the plurality of CBGs including a CBG having a first number of CBs and a CBG having a second number of CBs based on a total number of CBs in the first TB being greater than a value set via higher layer signaling; transmitting a first HARQ-ACK response including an ACK for each of at least one first CBG that was correctly decoded in the first TB and a NACK for each of at least one second CBG that was not correctly decoded in the first TB; receiving a second TB including the at least one second CBG as a CBG-based retransmission of the first TB during the first HARQ process; In response to receiving the second TB, transmitting a second HARQ-ACK response including (i) an ACK / NACK for each of the at least one second CBG according to a result of decoding the second TB, and (ii) an ACK for each of the at least one first CBG that was correctly decoded in the first TB; Including, The method of claim 1, wherein the terminal reports an ACK for the at least one first CBG until the end of the first HARQ process based on the at least one first CBG being correctly decoded once in the first TB.

14. A computer-readable storage medium storing instructions that, when executed by a processor of a terminal, cause the terminal to perform the method of claim 13.

15. An apparatus configured to transmit HARQ-ACK information on a code block group (CBG) basis, each CBG being a separate group of a plurality of code blocks (CBs), At least one processor; at least one computer memory operably connected to the at least one processor; The at least one computer memory, when executed, causes the at least one processor to: receiving a first transport block (TB) including a plurality of CBGs during a first HARQ process, and based on a total number of CBs in the first TB being greater than a value set via higher layer signaling, the plurality of CBGs include a CBG having a first number of CBs and a CBG having a second number of CBs; Transmitting a first HARQ-ACK response including an ACK for each of at least one first CBG that was correctly decoded in the first TB and a NACK for each of at least one second CBG that was not correctly decoded in the first TB; receiving a second TB including the at least one second CBG as a CBG-based retransmission of the first TB during the first HARQ process; storing instructions to perform operations including, in response to receiving the second TB, transmitting a second HARQ-ACK response including i) an ACK / NACK for each of the at least one second CBG in response to a result of decoding the second TB, and (ii) an ACK for each of the at least one first CBG that was correctly decoded in the first TB; An apparatus, wherein, based on the at least one first CBG being correctly decoded once in the first TB, the apparatus reports an ACK for the at least one first CBG until the end of the first HARQ process.

16. further comprising at least one transceiver; The apparatus of claim 15 , wherein the apparatus is a terminal in a wireless communication system.

17. 16. The apparatus of claim 15, wherein the apparatus is an ASIC or a digital signal processing device configured to control a terminal in a wireless communication system.

18. A method for receiving HARQ-ACK information on a code block group (CBG) basis, each of which is a separate group of a plurality of code blocks (CBs), by a base station, comprising: transmitting a first transport block (TB) including a plurality of CBGs during a first HARQ process, the plurality of CBGs including a CBG having a first number of CBs and a CBG having a second number of CBs based on a total number of CBs in the first TB being greater than a value set via higher layer signaling; receiving a first HARQ-ACK response including an ACK for each of at least one first CBG of the first TB and a NACK for each of at least one second CBG of the first TB; determining, based on the first HARQ-ACK response, that the at least one first CBG, indicated as an ACK, was correctly transmitted and that the at least one second CBG, indicated as a NACK, was not correctly transmitted; transmitting a second TB including the at least one second CBG as a CBG-based retransmission of the first TB during the first HARQ process; In response to transmitting the second TB, (i) receiving an ACK / NACK for each of the at least one second CBG according to a result of the CBG-based retransmission, and (ii) receiving a second HARQ-ACK response including an ACK for each of the at least one first CBG indicated as an ACK by the first HARQ-ACK response. Including, A method in which an ACK is received by the base station for the at least one first CBG until the end of the first HARQ process based on the at least one first CBG being correctly transmitted once through the first TB.

19. A computer-readable storage medium storing instructions that, when executed by a processor of a base station, cause the base station to perform the method of claim 18.

20. A base station configured to receive HARQ-ACK information on a code block group (CBG) basis, each CBG being a separate group of a plurality of code blocks (CBs), at least one memory configured to store instructions; at least one processor; The at least one processor executes the instructions to: During a first HARQ process, transmit a first transport block (TB) including a plurality of CBGs, and based on a total number of CBs in the first TB being greater than a value set via higher layer signaling, the plurality of CBGs include a CBG having a first number of CBs and a CBG having a second number of CBs; receiving a first HARQ-ACK response including an ACK for each of the at least one first CBG of the first TB and a NACK for each of the at least one second CBG of the first TB; determining, based on the first HARQ-ACK response, that the at least one first CBG, indicated as an ACK, was correctly transmitted and that the at least one second CBG, indicated as a NACK, was not correctly transmitted; transmitting a second TB including the at least one second CBG as a CBG-based retransmission of the first TB during a first HARQ process; In response to transmitting the second TB, the method is configured to perform operations including: (i) receiving an ACK / NACK for each of the at least one second CBG in response to a result of the CBG-based retransmission; and (ii) receiving a second HARQ-ACK response including an ACK for each of the at least one first CBG indicated as an ACK by the first HARQ-ACK response; A base station, wherein an ACK is received by the base station for the at least one first CBG until the end of the first HARQ process based on the at least one first CBG being correctly transmitted once through the first TB.

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