Methods, apparatus and systems for transmitting or receiving data channels and control channels

Abstract

This invention relates to methods, apparatus, and systems for transmitting or receiving data channels and control channels. A terminal for a wireless communication system and a wireless communication method using the terminal are disclosed. More specifically, a terminal and a wireless communication method using the terminal are disclosed. The terminal includes a communication module and a processor, wherein the processor: receives a Data Channel Interface (DCI) via a PDCCH indicating PDSCH scheduling information for each of one or more cells; identifies a transmission scheme in each cell based on the DCI format; receives the PDSCH of each of the one or more cells based on the PDCCH scheduling information; generates a HARQ-ACK bit sequence for the one or more cells based on the identified transmission scheme for each cell in response to receiving the PDSCH of each cell; and transmits the generated HARQ-ACK bit sequence.

Description

[0001] This application is a divisional application of patent application No. 201880057581.9 (International Application No. PCT / KR2018 / 008917), filed on March 5, 2020, with an international application date of August 6, 2018, entitled "Method, Apparatus and System for Transmitting or Receiving Data Channels and Control Channels in a Wireless Communication System". Technical Field

[0002] This invention relates to a wireless communication system. More particularly, it relates to wireless communication methods, apparatus, and systems for transmitting and receiving data channels and control channels. Background Technology

[0003] Since the commercialization of fourth-generation (4G) communication systems, efforts have been underway to develop new fifth-generation (5G) communication systems to meet the growing demand for wireless data services. 5G communication systems are referred to as systems beyond 4G networks, post-LTE systems, or new radio (NR) systems. To achieve high data rates, 5G communication systems include systems operating in ultra-high frequency (UHF) bands above 6 GHz (e.g., millimeter wave) and systems operating in bands below 6 GHz to ensure coverage, making implementation in base stations and terminals under consideration.

[0004] The 3GPP (3rd Generation Partnership Project) NR system improves network spectrum efficiency, enabling operators to deliver more data and voice services within a given bandwidth. As a result, in addition to supporting a large volume of voice calls, the 3GPP NR system is designed to meet the demands for high-speed data and multimedia transmission. The advantages of the NR system include support for high throughput, low latency, Frequency Division Duplex (FDD) and Time Division Duplex (TDD) on the same platform, improved end-user experience, and a simple architecture with low operating costs.

[0005] For more efficient data processing, the dynamic TDD of the NR system can vary the number of Orthogonal Frequency Division Multiplexing (OFDM) symbols available for uplink / downlink based on the data traffic direction of cell users. For example, when the downlink traffic volume of a cell is greater than the uplink traffic volume, the base station can allocate multiple downlink OFDM symbols to time slots (or subframes). Information regarding the time slot configuration should be sent to the terminal.

[0006] To mitigate path loss and increase transmission distance in the UHF band, technologies such as beamforming, massive MIMO, full-size MIMO (FD-MIMO), array antennas, analog beamforming, hybrid beamforming combining analog and digital beamforming, and massive MIMO are being discussed in 5G communication systems. Additionally, to improve network performance, technologies such as evolved small cells, advanced small cells, cloud radio access networks (cloud RAN), ultra-dense networks, device-to-device (D2D) communication, vehicle-to-everything (V2X) communication, wireless backhaul, non-terrestrial network (NTN) communication, mobile networks, cooperative communication, cooperative multipoint (CoMP), and interference cancellation are being developed for 5G communication systems. In addition, advanced compilation modulation (ACM) schemes such as hybrid FSK and QAM modulation (FQAM) and sliding window superposition compilation (SWSC), as well as advanced access technologies such as filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA) and sparse code multiple access (SCMA) are being developed in 5G systems.

[0007] Simultaneously, the internet is evolving from a human-centric network of connections where humans create and consume information into a distributed Internet of Things (IoT) network of components that exchange and process information between objects. Among these, the Internet of Everything (IoE) technology, which integrates big data processing technologies with cloud servers and other devices, is emerging. To realize IoT, technological elements such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology are required. Recently, technologies such as sensor networks, machine-to-machine communication (M2M), and machine-type communication (MTC) for connecting objects have been researched. In the IoT environment, intelligent internet technology (IT) services can be provided to collect and analyze data generated from connected objects and create new value in human life. By integrating and combining existing information technology (IT) with various industries, IoT can be applied to smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart appliances, advanced medical services, and other fields.

[0008] Therefore, various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, machine-to-machine (M2M) communication, and machine-type communication (MTC) have been implemented using schemes such as beamforming, MIMO, and array antennas (which are 5G communication technologies). As a big data processing technology, cloud radio access network (cloud RAN) is an example of the convergence of 5G and IoT technologies. Typically, mobile communication systems have been developed to provide voice services while ensuring user activity.

[0009] However, mobile communication systems are expanding not only in voice but also in data services, and they have now evolved to the point where they can provide high-speed data services. However, due to resource shortages and users' demands for high-speed services, more advanced mobile communication systems are needed within the current service offerings. Summary of the Invention

[0010] Technical issues

[0011] The object of this invention is to provide a method and apparatus for efficiently transmitting signals in a wireless communication system (particularly a cellular wireless communication system). Another object of this invention is to provide a method, apparatus, and system for transmitting and receiving downlink control channels.

[0012] The purpose of this invention is to provide a method for generating HARQ-ACK bit sequences when configured to enable block group (CBG) based transmission to a user equipment.

[0013] Furthermore, the object of the present invention is to provide a method for performing effective retransmission when configured to enable CBG-based transmission to a user equipment.

[0014] Furthermore, the object of the present invention is to provide a method for generating a HARQ-ACK bit sequence when a user equipment configured to enable CBG-based transmission fails to receive at least one PDCCH.

[0015] Technical solution

[0016] To address the aforementioned problems, the present invention provides user equipment for a wireless communication system and a wireless communication method.

[0017] First, an exemplary embodiment of the present invention provides a user equipment for a wireless communication system, including a communication module and a processor configured to control the communication module, wherein the processor receives downlink control information (DCI) via a physical downlink control channel (PDCCH) instructing physical downlink shared channel (PDSCH) scheduling information for each of one or more cells, wherein a code block group (CBG) based transmission is configured in at least one of the one or more cells, the DCI format based on the DCI identifies a transmission scheme in each cell, wherein the transmission scheme is a transport block (TB) based transmission or a CBG based transmission, the PDSCH of each of the one or more cells is received based on the PDCCH scheduling information, and in response to receiving the PDSCH of each cell, a hybrid automatic repeat request acknowledgment (HARQ-ACK) bit sequence for one or more cells is generated based on the identified transmission scheme of each cell, wherein within the HARQ-ACK bit sequence, the HARQ-ACK bit sequence for TB-based transmission and the HARQ-ACK bit sequence for CBG-based transmission are generated separately, and the generated HARQ-ACK bit sequence is transmitted.

[0018] Furthermore, an exemplary embodiment of the present invention provides a wireless communication method in a wireless communication system, comprising: receiving downlink control information (DCI) through a physical downlink control channel (PDCCH) that instructs physical downlink shared channel (PDSCH) scheduling information for each of one or more cells, wherein a code block group (CBG) based transmission is configured in at least one of the one or more cells; identifying a transmission scheme in each cell based on the DCI format of the DCI, wherein the transmission scheme is a transport block (TB) based transmission or a CBG based transmission; receiving the PDSCH of each of the one or more cells based on the scheduling information of the PDCCH; generating a hybrid automatic repeat request acknowledgment (HARQ-ACK) bit sequence for one or more cells based on the identified transmission scheme of each cell in response to receiving the PDSCH of each cell, wherein within the HARQ-ACK bit sequence, a HARQ-ACK bit sequence for TB-based transmission and a HARQ-ACK bit sequence for CBG-based transmission are generated separately, and transmitting the generated HARQ-ACK bit sequence.

[0019] One HARQ-ACK bit can be generated per transport block in the HARQ-ACK bit sequence for TB-based transmissions, and N HARQ-ACK bits can be generated per transport block in the HARQ-ACK bit sequence for CBG-based transmissions, where N can be the maximum number of CBGs configured for each transport block of the user equipment.

[0020] When the number M of CBGs transmitted through a specific cell configured for CBG-based transmission in one or more cells is less than N, the HARQ-ACK bits for the specific cell can consist of M HARQ-ACK bits and NM NACK bits for the transmitted CBGs.

[0021] The processor can receive a downlink allocation index (DAI) in DCI format and generate a HARQ-ACK bit sequence with reference to the DAI. The DAI can include a counter-DAI indicating the cumulative number of PDSCHs scheduled to the current cell and a total-DAI indicating the total number of PDSCHs scheduled for the entire cell.

[0022] DAI can be applied separately to HARQ-ACK bit sequences for TB-based transmissions and HARQ-ACK bit sequences for CBG-based transmissions.

[0023] Within the HARQ-ACK bit sequence, the HARQ-ACK bit sequence used for CBG-based transmissions can be appended to the HARQ-ACK bit sequence used for TB-based transmissions.

[0024] Next, another exemplary embodiment of the present invention provides a user equipment for a wireless communication system, including: a communication module; and a processor configured to control the communication module, wherein the processor receives a physical downlink control channel (PDCCH) indicating physical downlink shared channel (PDSCH) scheduling information for each of one or more cells, wherein block group-based (CBG) transmission is configured to be available in at least one of the one or more cells, a downlink allocation index (DAI) is received via the PDCCH, and the PDSCH scheduling information for each of the one or more cells is received. In response to receiving the PDSCH of each cell, the system generates a Hybrid Automatic Repeat Request Acknowledgment (HARQ-ACK) bit sequence for one or more cells with reference to the DAI. The HARQ-ACK bit sequence includes at least one of a HARQ-ACK bit sequence for transport block (TB) based transmissions and a HARQ-ACK bit sequence for CBG based transmissions. The DAI is applied separately to the HARQ-ACK bit sequence for TB-based transmissions and the HARQ-ACK bit sequence for CBG-based transmissions, and the generated HARQ-ACK bit sequence is transmitted.

[0025] Furthermore, another exemplary embodiment of the present invention provides a wireless communication method in a wireless communication system, comprising: receiving a physical downlink control channel (PDCCH) indicating physical downlink shared channel (PDSCH) scheduling information for each of one or more cells, wherein block group-based (CBG) transmissions are configured to be available in at least one of the one or more cells; receiving a downlink allocation index (DAI) via the PDCCH; receiving the PDSCH for each of the one or more cells based on the scheduling information of the PDCCH; in response to receiving the PDSCH for each cell, generating a hybrid automatic repeat request acknowledgment (HARQ-ACK) bit sequence for the one or more cells with reference to the DAI, wherein the HARQ-ACK bit sequence includes at least one of a HARQ-ACK bit sequence for transport block (TB)-based transmissions and a HARQ-ACK bit sequence for CBG-based transmissions, and wherein the DAI is applied separately to the HARQ-ACK bit sequence for TB-based transmissions and the HARQ-ACK bit sequence for CBG-based transmissions, and transmitting the generated HARQ-ACK bit sequence.

[0026] HARQ-ACK bit sequences can be generated based on the identified transmission scheme for each cell, and the transmission scheme for each cell can be based on TB or CBG.

[0027] The processor can receive downlink control information (DCI) via PDCCH, and the transmission scheme of each cell can be identified based on the DCI format.

[0028] One HARQ-ACK bit can be generated per transport block in the HARQ-ACK bit sequence for TB-based transmissions, and N HARQ-ACK bits can be generated per transport block in the HARQ-ACK bit sequence for CBG-based transmissions, where N can be the maximum number of CBGs configured for each transport block of the user equipment.

[0029] When the number M of CBGs transmitted through a specific cell configured for CBG-based transmission in one or more cells is less than N, the HARQ-ACK bits for the specific cell can consist of M HARQ-ACK bits and NM NACK bits used for the transmitted CBGs.

[0030] Within the HARQ-ACK bit sequence, the HARQ-ACK bit sequence used for CBG-based transmissions can be appended to the HARQ-ACK bit sequence used for TB-based transmissions.

[0031] The DAI applied to TB-based transmissions may include a counter-DAI indicating the cumulative number of TB-based PDSCHs scheduled to the current cell and a total-DAI indicating the total number of TB-based PDSCHs scheduled for the entire cell, and the DAI applied to CBG-based transmissions may include a counter-DAI indicating the cumulative number of CBG-based PDSCHs scheduled to the current cell and a total-DAI indicating the total number of CBG-based PDSCHs scheduled for the entire cell.

[0032] When the total -DAI indication of the DAI applied to a TB-based transmission is predetermined and no PDCCH is received for scheduling the TB-based transmission, the HARQ-ACK bit sequence can be configured to exclude the HARQ-ACK bit sequence for the TB-based transmission. Similarly, when the total -DAI indication of the DAI applied to a CBG-based transmission is predetermined and no PDCCH is received for scheduling the CBG-based transmission, the HARQ-ACK bit sequence can be configured to exclude the HARQ-ACK bit sequence for the CBG-based transmission.

[0033] The preset value can be binary "11".

[0034] The HARQ-ACK bit sequence can be sent via the Physical Uplink Shared Channel (PUSCH).

[0035] Beneficial effects

[0036] According to embodiments of the present invention, the overhead of downlink control information referenced by user equipment configured to enable CBG-based transmission in determining the HARQ-ACK bit sequence can be minimized. Therefore, according to embodiments of the present invention, the transmission efficiency of the network between the base station and user equipment can be improved.

[0037] Furthermore, according to embodiments of the present invention, the signaling overhead for retransmission requests can be minimized through effective signaling in the fallback mode.

[0038] The effects that can be obtained in this invention are not limited to those described above, and other effects not mentioned above will be clearly understood by those skilled in the art based on the following description. Attached Figure Description

[0039] Figure 1 The illustration shows an example of a wireless frame structure used in a wireless communication system.

[0040] Figure 2 This diagram illustrates an example of a downlink (DL) / uplink (UL) timeslot structure in a wireless communication system.

[0041] Figure 3This is a schematic diagram illustrating the physical channel used in the 3GPP system and the general signal transmission method using the physical channel.

[0042] Figure 4 The diagram illustrates the SS / PBCH block used for initial cell access in a 3GPP NR system.

[0043] Figure 5 The diagram illustrates the process of transmitting control information and the control channel in a 3GPP NR system.

[0044] Figure 6 This is a schematic diagram of the control resource set (CORESET) in a 3GPP NR system that can transmit the Physical Downlink Control Channel (PDCCH).

[0045] Figure 7 This is a schematic diagram illustrating the allocation of the CCE aggregated search space for the public search space and the UE-specific (or terminal-specific) search space.

[0046] Figure 8 This is a conceptual diagram illustrating carrier aggregation.

[0047] Figure 9 This is a schematic diagram used to describe single-carrier communication and multi-carrier communication.

[0048] Figure 10 This is a schematic diagram illustrating an example of cross-carrier scheduling technology.

[0049] Figure 11 The diagram illustrates the code block group (CBG) configuration and its time-frequency resource mapping according to an embodiment of the present invention.

[0050] Figure 12 The illustration shows the process by which a base station performs TB-based or CBG-based transmission according to an embodiment of the present invention, and a user equipment responds by performing HARQ-ACK transmission.

[0051] Figure 13 The illustration shows an embodiment of the method for receiving HARQ-ACK feedback and backoff indicators.

[0052] Figure 14 The illustration shows another embodiment of the method for receiving HARQ-ACK feedback and backoff indicators.

[0053] Figure 15 The illustration shows an example of a user equipment sending a HARQ-ACK and backoff indicator for CBG according to the above embodiment.

[0054] Figures 16 to 19 The illustration shows an additional embodiment in which the user equipment sends a HARQ-ACK and a backoff indicator for the CBG.

[0055] Figure 20 The illustration shows an example of a downlink allocation index (DAI) value mapped to each component carrier.

[0056] Figure 21 and Figure 22 The illustration shows a DAI signaling method and a HARQ-ACK bit sequence generation method based on the first embodiment of the present invention.

[0057] Figure 23 The figure illustrates a DAI signaling method according to a second embodiment of the present invention.

[0058] Figure 24 The figure illustrates a DAI signaling method according to a third embodiment of the present invention.

[0059] Figure 25 and 26 The illustration is based on an embodiment of generating a HARQ-ACK bit sequence from a DAI signal transmitted according to the third embodiment described above.

[0060] Figure 27 The illustration is based on another embodiment of generating a HARQ-ACK bit sequence using DAI transmitted by a signal according to the third embodiment described above.

[0061] Figure 28 The figure illustrates a DAI signaling method according to a fourth embodiment of the present invention.

[0062] Figure 29 The figure illustrates a DAI signaling method according to a fifth embodiment of the present invention.

[0063] Figure 30 The figure illustrates a DAI signaling method according to a sixth embodiment of the present invention.

[0064] Figure 31 The illustration is based on an embodiment of generating a HARQ-ACK bit sequence from DAI transmitted by a signal according to the sixth embodiment described above.

[0065] Figure 32 The figure illustrates a DAI signaling method according to a seventh embodiment of the present invention.

[0066] Figure 33 The illustration is based on an embodiment of generating a HARQ-ACK bit sequence from DAI transmitted by a signal according to the seventh embodiment described above.

[0067] Figure 34 The figure illustrates a DAI signaling method according to an eighth embodiment of the present invention.

[0068] Figure 35 The figure illustrates a DAI signaling method according to a ninth embodiment of the present invention.

[0069] Figure 36 The illustration is based on an embodiment of generating a HARQ-ACK bit sequence from DAI transmitted by a signal according to the ninth embodiment described above.

[0070] Figure 37 The figure illustrates a DAI signaling method according to a tenth embodiment of the present invention.

[0071] Figure 38 The illustration shows a HARQ-ACK compression method according to an embodiment of the present invention.

[0072] Figure 39 and Figure 40 The illustration shows a method for performing HARQ-ACK spatial binding according to an embodiment of the present invention.

[0073] Figure 41 and Figure 42 A method for performing spatial binding of HARQ-ACK according to an embodiment of the present invention is illustrated in more detail.

[0074] Figure 43 This is a block diagram illustrating the configuration of a terminal and a base station according to an embodiment of the present invention. Detailed Implementation

[0075] The terminology used in this specification employs general terms that are currently used as broadly as possible in consideration of the functionality of this invention, but these terms may be modified according to the intent, practice, and emergence of new technologies of those skilled in the art. Furthermore, in certain cases, there are terms arbitrarily chosen by the applicant, and in such cases, their meaning will be described in the corresponding descriptive section of the invention. Therefore, the purpose of disclosing the terminology used in this specification is to analyze it not only based on its name, but also on the substantive meaning of the terms and content within the specification.

[0076] Throughout the specification and subsequent claims, when describing an element as "connected" to another element, the element may be "directly connected" to the other element or "electrically connected" to the other element via a third element. Furthermore, unless explicitly stated otherwise, the word "comprising" will be understood to imply the inclusion of the stated elements but does not exclude any other elements, unless otherwise stated. Additionally, in some exemplary embodiments, limitations based on specific thresholds such as "greater than or equal to" or "less than or equal to" may be appropriately replaced with "greater than" or "less than," respectively.

[0077] 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-FDMA (SC-FDMA). CDMA can be implemented using wireless technologies such as Universal Terrestrial Radio Access (UTRA) or CDMA 2000. TDMA can be implemented using wireless technologies such as GSM / GPRS / EDGE GSM evolution. OFDMA can be implemented using wireless technologies such as IEEE 802.11 (i.e., Wi-Fi), IEEE 802.16 (i.e., WiMAX), IEEE 802-20, and evolved UTRA (E-UTRA). UTRA is part of the Universal Mobile Telecommunications System (UMTS). 3GPP Long Term Evolution (LTE) is part of Evolved UMTS (E-UMTS) which uses Evolved UMTS Terrestrial Radio Access (E-UTRA), and LTE Advanced (LTE-A) is an evolved version of 3GPP LTE. 3GPP NR is a system designed separately from LTE / LTE-A and is intended to support Enhanced Mobile Broadband (eMBB), Ultra-Reliable and Low-Latency Communications (URLLC), and Massive Machine-Type Communications (mMTC) services, as required by IMT-2020. For clarity, 3GPP NR is primarily described, but the technical concept of this invention is not limited thereto.

[0078] Unless otherwise specified in this specification, a base station may include a next-generation node B (gNB) as defined in 3GPP NR. Furthermore, unless otherwise explained, a terminal may include a user equipment (UE).

[0079] Figure 1 This diagram illustrates an example of a wireless frame structure used in a wireless communication system. (Reference) Figure 1 In 3GPP NR systems, radio frames (or radio frames) can have a duration of 10ms (Δf). max N f / 100)*T c The length of the radio frame is Δf. Additionally, a radio frame consists of 10 subframes (SF) of equal size. Here, Δf max =480*10 3 Hz, N f =4096, T c =1 / (Δf) ref *N f,ref ), Δf ref =15*10 3 Hz, and N f,ref=2048. Numbers from 0 to 9 can be assigned to the 10 subframes within a single radio frame. Each subframe has a length of 1 ms and can include one or more time slots depending on the subcarrier spacing. More specifically, in 3GPP NR systems, the usable subcarrier spacing is 15*2. μ kHz. μ can have values ​​from μ = 0 to 4 as the subcarrier spacing configuration. That is, 15kHz, 30kHz, 60kHz, 120kHz, or 240kHz can be used for the subcarrier spacing. A subframe with a length of 1ms can consist of 2 μ It consists of 2 time slots. In this case, the length of each time slot is 2. -μ ms. From 0 to 2 μ-1 The numbers can be assigned to 2 within a subframe. μ One time slot. Additionally, 0 to 10*2 μ The number -1 can be assigned to a time slot within a subframe. Time resources can be distinguished by at least one of the radio frame number (also known as the radio frame index), the subframe number (also known as the subframe index), and the time slot number (or time slot index).

[0080] Figure 2 This diagram illustrates an example of a downlink (DL) / uplink (UL) timeslot structure in a wireless communication system. Specifically, Figure 2 This illustrates the structure of the resource grid in a 3GPP NR system. Each antenna port has its own resource grid. (Reference) Figure 2 A time slot comprises multiple Orthogonal Frequency Division Multiplexing (OFDM) symbols in the time domain and multiple resource blocks (RBs) in the frequency domain. An OFDM symbol also refers to a symbol duration. Unless otherwise specified, an OFDM symbol may simply be referred to as a symbol. Reference Figure 2 The signal transmitted in each time slot can be composed of N size,μ grid,x *N RB sc Subcarriers and N slot symb A resource grid representation of N OFDM symbols. Here, for the downlink resource grid x = DL, and for the uplink resource grid x = UL. size,μ grid,x This represents the number of resource blocks configured with μ based on the subcarrier spacing (in which case x is either DL or UL), and N slot symb This indicates the number of OFDM symbols in the time slot. N RB sc It is the number of subcarriers that make up an RB and N RB sc=12. Depending on the multiple access scheme, OFDM symbols can be called cyclic prefix OFDM (CP-OFDM) symbols or discrete Fourier transform extended OFDM (DFT-S-OFDM) symbols.

[0081] The number of OFDM symbols included in a time slot can vary depending on the length of the cyclic prefix (CP). For example, with a normal CP, a time slot includes 14 OFDM symbols, but with an extended CP, a time slot may include 12 OFDM symbols. In certain embodiments, the extended CP may be used only with a 60 kHz subcarrier spacing. Figure 2 In this example, for ease of description, one time slot comprises 14 OFDM symbols; however, embodiments of the invention can be applied in a similar manner to time slots with different numbers of OFDM symbols. (See references) Figure 2 Each OFDM symbol includes N in the frequency domain. size,μ grid,x *N RB sc Subcarriers. Subcarriers can be categorized into data subcarriers for data transmission, reference signal subcarriers for transmitting reference signals, and guard bands. The carrier frequency is also called the center frequency (fc).

[0082] RB can be derived from N in the frequency domain RB sc (For example, 12) consecutive subcarriers are used for definition. For reference, a resource comprising one OFDM symbol and one subcarrier can be referred to as a resource element (RE) or tone. Therefore, an RB can include N slot symb *N RB sc Each resource element in the resource grid can be uniquely defined by a pair of indices (k, 1) in a time slot. k can be from 0 to N in the frequency domain. size,μ grid,x *N RB sc -1 is the index number, and 1 can be from 0 to N in the time domain. slot symb -1 index.

[0083] In order for a user equipment (UE) to receive or transmit signals to a base station, the UE's time / frequency synchronization can be synchronized with the base station's time / frequency synchronization. This is because the base station and the UE need to be synchronized so that the UE can determine the time and frequency parameters required to demodulate the DL signal and transmit the UL signal at the correct time.

[0084] Each symbol of a radio frame operating in Time Division Duplex (TDD) or unpaired spectrum can be configured as at least one of a DL symbol, a UL symbol, or a flexible symbol. Radio frames operating as downlink carriers in Frequency Division Duplex (FDD) or paired spectrum can consist of downlink symbols or flexible symbols, while radio frames operating as uplink carriers can consist of uplink symbols or flexible symbols. In downlink symbols, downlink transmission is possible while uplink transmission is not, and in uplink symbols, uplink transmission is possible while downlink transmission is not. The flexible symbol can be determined to be used for downlink or uplink based on the signal.

[0085] Information regarding the type of each symbol (i.e., information indicating any of downlink symbols, uplink symbols, and flexible symbols) can be configured by cell-specific (or public) Radio Resource Control (RRC) signals. Additionally, information regarding the type of each symbol can be configured separately by UE-specific (or dedicated) RRC signals. The base station uses cell-specific RRC signals to indicate i) the period of cell-specific time slot configuration, ii) the number of time slots with only downlink symbols starting from the beginning of the cell-specific time slot configuration period, iii) the number of downlink symbols starting from the first symbol of the next time slot immediately following a time slot with only downlink symbols, iv) the number of time slots with only uplink symbols starting from the end of the cell-specific time slot configuration period, and v) the number of uplink symbols starting from the last symbol of the time slot immediately preceding a time slot with only uplink symbols. Here, symbols not configured as either uplink or downlink symbols are flexible symbols.

[0086] When information related to symbol type is configured with a UE-specific RRC signal, the base station can use a cell-specific RRC signal to transmit flexible symbols, either downlink or uplink symbols. In this case, the UE-specific RRC signal cannot change the downlink or uplink symbol configured by the cell-specific RRC signal to another symbol type. The UE-specific RRC signal can transmit the corresponding N for each time slot. slot symb The number of downlink symbols in each symbol and the corresponding time slot N slot symb The number of uplink symbols in a time slot. In this case, downlink symbols of the time slot can be configured continuously from the first symbol to the i-th symbol. Alternatively, uplink symbols of the time slot can be configured continuously from the j-th symbol to the last symbol (where i < j). Symbols in a time slot that are not configured as either uplink or downlink symbols are flexible symbols.

[0087] The symbol type configured by the above RRC signals can be referred to as a semi-static DL / UL configuration. In the previous semi-static DL / UL configuration configured by RRC signals, flexible symbols can be indicated as downlink symbols, uplink symbols, or flexible symbols through the dynamic slot format information (SFI) sent by the physical downlink control channel (PDCCH). In this case, the downlink or uplink symbol configured by the RRC signals does not change to another symbol type. Table 1 illustrates the dynamic SFIs that the base station can configure for the terminal.

[0088] [Table 1]

[0089]

[0090] In Table 1, D represents the downlink symbol, U represents the uplink symbol, and X represents the flexible symbol. As shown in Table 1, up to two DL / UL handovers can be allowed in a single time slot.

[0091] Figure 3 This is a schematic diagram used to explain the physical channels used in 3GPP systems (e.g., NR) and the general signal transmission methods using those physical channels. When a user equipment (UE) is powered on or enters a new cell, the UE performs an initial cell search (S101). Specifically, the UE can synchronize with the base station during the initial cell search. To do this, the UE can receive the primary synchronization signal (PSS) and secondary synchronization signal (SSS) from the base station, synchronize with the base station, and obtain information such as the cell ID. Afterward, the UE can receive the physical broadcast channel from the base station and obtain intra-cell broadcast information.

[0092] After completing the initial cell search, the user equipment receives the physical downlink control channel (PDCCH) and the physical downlink shared channel (PDSCH) based on the information carried in the PDCCH, enabling the user equipment to obtain more specific system information than the system information obtained through the initial cell search (S102).

[0093] When a user equipment (UE) initially accesses a base station or when there are no radio resources available for signal transmission, the UE can perform a random access procedure (S103 to S106) with the base station. First, the UE can send a specific sequence as a preamble via the Physical Random Access Channel (PRACH) (S103), and receive a response message for the preamble from the base station on the PDCCH and the corresponding PDSCH (S104). In the case of a contention-based RACH, a contention resolution procedure can be performed separately.

[0094] Following the above process, the user equipment receives the PDCCH / PDSCH (S107) and transmits the Physical Uplink Shared Channel (PUSCH) / Physical Uplink Control Channel (PUCCH) (108) as part of the general phase / DL signal transmission process. Specifically, the user equipment can receive downlink control information (DCI) via the PDCCH. The DCI may include control information, such as the user equipment's resource allocation information. Furthermore, the format of the DCI can vary depending on its intended use. The control information transmitted by the user equipment to the base station via the uplink includes DL / UL ACK / NACK signals, Channel Quality Indicator (CQI), Precoding Matrix Index (PMI), and Rank Indicator (RI). In this case, CQI, PMI, and RI may be included in the Channel State Information (CSI). In the 3GPP NR system, the user equipment can transmit control information such as the aforementioned HARQ-ACK and CSI via the PUSCH and / or PUCCH.

[0095] Figure 4 The diagram illustrates the SS / PBCH block for initial cell access in a 3GPP NR system. When a user equipment (UE) is powered on and attempts to access a new cell, the UE can obtain time and frequency synchronization with the cell and perform an initial cell search procedure. During the initial cell search, the UE can detect the physical cell identifier (N) of the cell. cell ID To this end, user equipment can receive synchronization signals from the base station (e.g., primary synchronization signal (PSS) and secondary synchronization signal (SSS)) and synchronize with the base station. In this case, the user equipment can obtain information such as cell identifier (ID).

[0096] refer to Figure 4 (a) describes the synchronization signal (SS) in more detail. The synchronization signal can be divided into the PSS and the SSS. The PSS is used to obtain time-domain synchronization and / or frequency-domain synchronization, such as OFDM symbol synchronization and slot synchronization. The SSS is used to obtain frame synchronization and cell group ID. Reference Figure 4(a) and Table 2, the SS / PBCH block consists of 20 consecutive RBs (=240 subcarriers) on the frequency axis and 4 consecutive OFDM symbols on the time axis. Here, in the SS / PBCH block, the PSS in the first OFDM symbol and the SSS in the third OFDM symbol are transmitted via subcarriers 56 to 182. Here, the lowest subcarrier index of the SS / PBCH block is numbered starting from 0. In the first OFDM symbol transmitting the PSS, the base station does not transmit signals via the remaining subcarriers (i.e., subcarriers 0 to 55 and 183 to 239). In the third OFDM symbol transmitting the SSS, the base station does not transmit signals via subcarriers 48 to 55 and 183 to 191. In the SS / PBCH block, in addition to the signals mentioned above, the base station transmits the Physical Broadcast Channel (PBCH) signals via the remaining REs.

[0097] [Table 2]

[0098]

[0099] A Physical Layer Cell ID (PSS) can represent a total of 1008 unique PSS cell IDs through a combination of three PSS and SSS. Specifically, each PSS cell ID is grouped into 336 PSS cell identifier groups, where each group contains three unique identifiers, ensuring that each PSS cell ID is only a part of one PSS cell identifier group. Therefore, the Physical Layer Cell ID N... cell ID =3N (1) ID +N (2) ID The ID can be determined by an index N ranging from 0 to 335, indicating a physical layer cell identifier group. (1) ID and an index N indicating the range of physical layer identifiers in the physical layer cell identifier group from 0 to 2. (2) ID Definition. User equipment (UE) can detect a Physical Layer Sequence Segment (PSS) and identify one of three unique Physical Layer Identifiers (PLIs). Additionally, UE can detect a Single Physical Layer Sequence Segment (SSS) and identify one of 336 Physical Layer Cell IDs associated with the PSS. In this case, the sequence d of the PSS... PSS (n) is as follows.

[0100] d PSS (n) = 1 - 2x(m)

[0101]

[0102] 0≤n<127

[0103] Here, x(i+7) = (x(i+4) + x(i)) mod 2, and

[0104] [x(6) x(5) x(4) x(3) x(2) x(1) x(0)]=[1 1 1 0 1 1 0]

[0105] Additionally, the sequence d of SSS PSS (n) is as follows.

[0106] d SSS (n)=[1-2x0((n+m0)mod 127)][1-2x1((n+m1)mod 127)]

[0107]

[0108] 0≤n<127

[0109] Here, and

[0110] [x0(6) x0(5) x0(4) x0(3) x0(2) x0(1) x0(0)]=[0 0 00 0 0 1]

[0111] [x1(6) x1(5) x1(4) x1(3) x1(2) x1(1) x1(0)]=[0 0 0 0 0 0 1]

[0112] A 10ms wireless frame can be divided into two half-frames, each 5ms long. (Reference) Figure 4(b) describes the time slots for transmitting the SS / PBCH block in each half-frame. The time slot for transmitting the SS / PBCH block can be any of cases A, B, C, D, and E. In case A, the subcarrier spacing is 15 kHz and the start time of the SS / PBCH block is {2,8} + the 14th*n symbol. In this case, at carrier frequencies of 3 GHz or lower, n = 0, 1. Alternatively, at frequencies above 3 GHz and below 6 GHz, n = 0, 1, 2, or 3. In case B, the subcarrier spacing is 30 kHz and the start time of the SS / PBCH block is {4,8,16,20} + the 28th*n symbol. In this case, at carrier frequencies of 3 GHz or lower, n = 0, 1. Alternatively, at frequencies above 3 GHz and below 6 GHz, n = 0 or 1. In case C, the subcarrier spacing is 30 kHz and the start time of the SS / PBCH block is {2,8} + the 14th*n symbol. In this case, at carrier frequencies of 3 GHz or lower, n = 0 or 1. Additionally, at frequencies above 3 GHz and below 6 GHz, n = 0, 1, 2, or 3. In case D, the subcarrier spacing is 120 kHz, and the start time of the SS / PBCH block is {4, 8, 16, 20} + 28*n. In this case, at carrier frequencies of 6 GHz or higher, n = 0, 1, 2, 3, 5, 6, 7, 8, 10, 11, 12, 13, 15, 16, 17, or 18. In case E, the subcarrier spacing is 240 kHz, and the start time of the SS / PBCH block is {8, 12, 16, 20, 32, 36, 40, 44} + the 56th*nth symbol. In this case, at carrier frequencies of 6 GHz or higher, n = 0, 1, 2, 3, 5, 6, 7, or 8.

[0113] Figure 5 The diagram illustrates the transmission process of control information and the control channel in a 3GPP NR system. (Reference) Figure 5(a) The base station may add a Cyclic Redundancy Check (CRC) masked by a Radio Network Temporary Identifier (RNTI) (e.g., XOR operation) to control information (e.g., downlink control information, DCI) (S202). The base station may scramble the CRC using an RNTI value determined according to the purpose / objective of each control information. A common RNTI used by one or more terminals may include at least one of System Information RNTI (SI-RNTI), Paging RNTI (P-RNTI), Random Access RNTI (RA-RNTI), and Transmit Power Control RNTI (TPC-RNTI). Additionally, UE-specific RNTIs may include at least one of Cell Temporary RNTI (C-RNTI) and CS-RNTI. Thereafter, the base station may perform rate matching based on the amount of resources available for PDCCH transmission after performing channel compilation (e.g., polarization compilation) (S204) (S206). Subsequently, the base station may multiplex the DCI based on the PDCCH structure based on Control Channel Elements (CCE) (S208). Furthermore, the base station applies additional processes (such as scrambling, modulation (e.g., QPSK), and interleaving) to the multiplexed DCI (S210) and then maps it to the resources to be transmitted. A CCE is the basic resource unit used for a PDCCH, and a CCE can consist of multiple (e.g., six) Resource Element Groups (REGs). A REG can consist of multiple (e.g., 12) REs. The number of CCEs used for a PDCCH can be defined as the aggregation level. In 3GPP NR systems, aggregation levels of 1, 2, 4, 8, or 16 can be used. Figure 5 (b) is a schematic diagram illustrating CCE aggregation levels and PDCCH multiplexing. In this case, the type of CCE aggregation level used for a PDCCH and the corresponding CCEs transmitted in the control area are described.

[0114] Figure 6 This diagram illustrates a control resource set (CORESET) for transmitting the Physical Downlink Control Channel (PDCCH) in a 3GPP NR system. A CORESET is the time-frequency resource for transmitting the PDCCH (i.e., control signals for user equipment). Furthermore, the search space described below can be mapped to a CORESET. Therefore, user equipment can decode the PDCCH mapped to a CORESET by monitoring the time-frequency region designated as the CORESET, rather than monitoring all frequency bands used for PDCCH reception. The base station can configure one or more CORESETs for each cell for user equipment. A CORESET can be configured with up to three consecutive symbols on the time axis. Additionally, a CORESET can be configured in units of six consecutive PRBs on the frequency axis. Figure 5In this embodiment, CORESET#1 is configured with consecutive PRBs, while CORESET#2 and CORESET#3 are configured with non-consecutive PRBs. A CORESET can be located in any symbol within a time slot. For example, in... Figure 5 In the embodiments, CORESET#1 starts from the first symbol of the time slot, CORESET#2 starts from the fifth symbol of the time slot, and CORESET#9 starts from the ninth symbol of the time slot.

[0115] Figure 7 This is a schematic diagram illustrating a method for setting up a PDCCH search space in a 3GPP NR system. To transmit PDCCHs to user equipment (UEs), each CORESET can have at least one search space. In embodiments of the invention, the search space is a combination of all time-frequency resources through which UEs can transmit their PDCCHs (hereinafter referred to as the PDCCH candidate set). The search space can include a common search space that 3GPP NR UEs must jointly search, and a terminal-specific or UE-specific search space that a particular UE must search. In the common search space, it is able to monitor PDCCHs that are jointly set to be searched by all UEs belonging to the same base station cell. In the common search space, it is set to monitor PDCCHs. Furthermore, in the UE-specific search space, each UE can be set to monitor PDCCHs allocated to each UE in different search space locations according to the UE. Since the control area to which PDCCHs can be allocated is limited, the corresponding UE-specific search space can partially overlap with the search spaces of other UEs. Monitoring PDCCHs includes blindly decoding PDCCH candidates in the search space. A successful blind decoding can be expressed as (successfully) detecting / receiving a PDCCH. Furthermore, blind decoding failure can be expressed as PDCCH not being detected / received or PDCCH not being successfully detected / received.

[0116] For ease of explanation, a PDCCH scrambled with a known Group Common (GC) RNTI for transmitting UL control information to one or more user equipments is called a Group Common (GC) PDCCH or a common PDCCH. Conversely, a PDCCH scrambled with a UE-specific RNTI known to a specific user equipment for transmitting UL scheduling information or DL ​​scheduling information to a specific user equipment is called a UE-specific PDCCH. A common PDCCH can be included in the common search space, and a UE-specific PDCCH can be included in either the common search space or the UE-specific PDCCH.

[0117] The base station can use the PDSCH to signal at least one of the following to each user equipment or user equipment group: information related to the allocation of resources for the paging channel (PCH) and downlink shared channel (DL-SCH) (i.e., DL clearance), or information related to the allocation of resources for the UL-SCH (i.e., UL clearance), and HARQ information. The base station can also use the PDSCH to transmit PCH transport blocks and DL-SCH transport blocks. The base station can use the PDSCH to transmit data other than specific control information or specific service data. Additionally, user equipment can use the PDSCH to receive data excluding specific control information or specific service data.

[0118] A base station can include information in the PDCCH about which user equipment (one or more user equipments) the PDSCH data is sent to and how the corresponding user equipment receives and decodes the PDSCH data, and then transmits the PDCCH. For example, suppose the DCI transmitted via a particular PDCCH is a CRC masked by an RNTI called "A", and the DCI indicates that the PDSCH is allocated to a radio resource called "B" (e.g., frequency location) and indicates transmission format information called "C" (e.g., block size, modulation scheme, compilation information, etc.). User equipment monitors the PDCCH using the RNTI information it possesses. In this case, when a user equipment is present blindly decoding the PDCCH with an RNTI of "A", the corresponding user equipment receives the PDCCH and, through the information in the received PDCCH, receives the PDSCH indicated by "B" and "C".

[0119] Table 3 illustrates an example of the Physical Uplink Control Channel (PUCCH) used in a wireless communication system.

[0120] [Table 3]

[0121] PUCCH format Length in OFDM symbol Number of bits 0 1-2 ≤2 1 4-14 ≤2 2 1-2 ＞2 3 4-14 ＞2 4 4-14 ＞2

[0122] PUCCH can be used to send the following uplink control information (UCI).

[0123] - Scheduling Request (SR): Information used to request UL UL-SCH resources.

[0124] -HARQ-ACK: A response to the PDCCH (indicating DL SPS release) and / or to a DL transport block (TB) on the PDSCH. HARQ-ACK indicates whether information transmitted via the PDCCH or PDSCH has been received. HARQ-ACK responses include positive ACK (ACK for short), negative ACK (NACK for short), discontinuous transmission (DTX), or NACK / DTX. Here, the term HARQ-ACK is used interchangeably with HARQ ACK / NACK and ACK / NACK. Typically, ACK can be represented by a bit value of 1, and NACK can be represented by a bit value of 0.

[0125] - Channel State Information (CSI): This is feedback information about the DL channel. It is generated by the user equipment based on the CSI reference signal (RS) transmitted by the base station. MIMO-related feedback information includes the Rank Indicator (RI) and the Precoding Matrix Indicator (PMI). The CSI can be divided into CSI Part 1 and CSI Part 2 based on the information indicated by the CSI.

[0126] In the 3GPP NR system, five PUCCH formats can be used to support various service scenarios, channel environments, and frame structures.

[0127] PUCCH format 0 is a format that can transmit 1 or 2 bits of HARQ-ACK information or SR. PUCCH format 0 can be transmitted using one or two OFDM symbols on the time axis and one RB on the frequency axis. When transmitting PUCCH format 0 with two OFDM symbols, the same sequence for both symbols can be transmitted through different RBs. Thus, the user equipment can obtain frequency diversity gain. More specifically, the user equipment can, according to M... bit One bit UCI (M bit =1 or 2) Determine the value m of the circular shift. cs And will be achieved by cyclically shifting a basic sequence of length 12 by a predetermined value m. cs The obtained sequence is mapped to an OFDM symbol and 12 REs of a PRB and transmitted. The number of cyclic shifts available at the user equipment is 12 and M... bit When M = 1, 1 bit UCI 0 and UCI 1 can be represented by a sequence of two cyclic shifts corresponding to a difference of 6 in the cyclic shift values. Additionally, when M... bit When =2, then the 2-bit UCI 00, 01, 11, 10 can be represented by a sequence of four cyclic shifts with a difference of 3 from the cyclic shift value.

[0128] PUCCH format 1 can transmit 1 or 2 bits of HARQ-ACK information or SR. PUCCH format 1 can be transmitted using consecutive OFDM symbols on the time axis and one PRB on the frequency axis. Here, the number of OFDM symbols used by PUCCH format 1 can be one of 4 to 14. More specifically, M bit A UCI of 1 can be modulated using BPSK. User equipment can use Quadrature Phase Shift Keying (QPSK) to modulate M... bits =2 UCI. The signal is obtained by multiplying the modulated complex-valued symbol d(0) by a sequence of length 12. The user equipment transmits the obtained signal by expanding the even-numbered OFDM symbols assigned with PUCCH format 1 using time-axis orthogonal cover codes (OCC). PUCCH format 1 determines the maximum number of different user equipments multiplexed in the same RB based on the length of the OCC to be used. In the odd-numbered OFDM symbols of PUCCH format 1, the demodulation reference signal (DMRS) is expanded with OCC and mapped.

[0129] PUCCH format 2 can transmit more than 2 bits of uplink control information (UCI). PUCCH format 2 can be transmitted using one or two OFDM symbols on the time axis and one or more RBs on the frequency axis. When transmitting PUCCH format 2 with two OFDM symbols, the same sequence for two different OFDM symbols can be transmitted through different RBs. In this way, the user equipment can obtain frequency diversity gain. More specifically, M... bit One bit UCI (M bit >2) RBs that are bit-level scrambled, QPSK modulated, and mapped to one or more OFDM symbols. Here, the number of RBs can be any from 1 to 16.

[0130] PUCCH format 3 or PUCCH format 4 can transmit more than 2 bits of UCI. PUCCH format 3 or PUCCH format 4 can be transmitted using consecutive OFDM symbols on the time axis and one PRB on the frequency axis. The number of OFDM symbols occupied by PUCCH format 3 or PUCCH format 4 can be one of 4 to 14. Specifically, the user equipment uses π / 2-binary phase shift keying (BPSK) or QPSK modulation. bit One bit UCI (M bit >2) To generate complex-valued symbols d(0)~d(Msymb-1). Here, when using π / 2-BPSK, M symb =M bit And when using QPSK, M symb =M bit / 2. User equipment (UE) may not apply block spread to PUCCH format 3. However, UE can apply block spread to one RB (i.e., 12 subcarriers) using a 12-length PreDFT-OCC, enabling PUCCH format 4 to have two or four multiplexing capacities. UE performs transmit precoding (or DFT precoding) on ​​the spread signal and maps it to each RE to transmit the spread signal.

[0131] In this scenario, the number of redundancies (RBs) occupied by PUCCH format 2, PUCCH format 3, or PUCCH format 4 can be determined based on the length and maximum bit rate of the UCI sent by the user equipment (UE). When the UE uses PUCCH format 2, it can send HARQ-ACK and CSI information together with the PUCCH. When the number of RBs that the UE can send exceeds the maximum number of RBs that can be used with PUCCH format 2, PUCCH format 3, or PUCCH format 4, the UE can send only the remaining UCI information and omit some UCI information based on the priority of the UCI information.

[0132] PUCCH format 1, PUCCH format 3, or PUCCH format 4 can be configured via the RRC signal to indicate frequency hopping in the time slot. When configuring frequency hopping, the index of the RB to be hopped can be configured using the RRC signal. When PUCCH format 1, PUCCH format 3, or PUCCH format 4 is transmitted over N OFDM symbols on the time axis, the first hop can have floor(N / 2) OFDM symbols, and the second hop can have ceil(N / 2) OFDM symbols.

[0133] PUCCH format 1, PUCCH format 3, or PUCCH format 4 can be configured to be repeatedly transmitted in multiple time slots. In this case, the number K of time slots for repeated PUCCH transmission can be configured via the RRC signal. The PUCCHs to be repeatedly transmitted begin at the same OFDM symbol position in each time slot and have the same length. When any OFDM symbol in the time slot requiring the user equipment to transmit PUCCH is indicated as a DL symbol by the RRC signal, the user equipment may choose not to transmit the PUCCH in the corresponding time slot and delay the transmission of the PUCCH to the next time slot.

[0134] In 3GPP NR systems, user equipment (UEs) can perform transmission / reception using bandwidth less than or equal to the carrier (or cell) bandwidth. For this purpose, UEs can be configured with a bandwidth portion (BWP) consisting of a continuous bandwidth that is part of the carrier bandwidth. UEs operating under TDD or in unpaired spectrum can configure up to four DL / UL BWP pairs on a single carrier (or cell). Additionally, UEs can activate one DL / UL BWP pair. UEs operating under FDD or in paired spectrum can receive up to four DL BWPs on a DL carrier (or cell) and up to four UL BWPs on a UL carrier (or cell). UEs can activate one DLBWP and one UL BWP for each carrier (or cell). UEs may or may not perform reception or transmission in time-frequency resources other than the activated BWPs. The activated BWP can be referred to as the active BWP.

[0135] The base station can use downlink control information (DCI) to indicate to the user equipment (UE) the active BWP among its configured BWPs. The BWP indicated by the DCI is activated, and the other configured BWPs are deactivated. In a carrier (or cell) operating in TDD, the base station may include a bandwidth portion indicator (BPI) indicating the BWP to be activated in the DCI of the scheduling PDSCH or PUSCH to change the UE's DL / UL BWP pair. The UE can receive the DCI of the scheduling PDSCH or PUSCH and can identify the DL / UL BWP pair activated based on the BPI. For a DL carrier (or cell) operating in FDD, the base station may include a BPI indicating the BWP to be activated in the DCI of the scheduling PDSCH to change the UE's DL BWP. For a UL carrier (or cell) operating in FDD, the base station may include a BPI indicating the BWP to be activated in the DCI of the scheduling PUSCH to change the UE's ULBWP.

[0136] Figure 8 This is a conceptual diagram illustrating carrier aggregation. Carrier aggregation is a method in which user equipment uses multiple frequency blocks or cells (in a logical sense) including UL resources (or component carriers) and / or DL ​​resources (or component carriers) as a large logical frequency band so that the wireless communication system can use a wider frequency band. In the following text, for ease of description, the term "component carrier" will be used.

[0137] refer to Figure 8 As an example of a 3GPP NR system, the total system bandwidth includes up to 16 component carriers, and each component carrier can be capable of having a bandwidth of up to 400 MHz. Component carriers can include one or more physically contiguous subcarriers. Although in Figure 8The figure shows each component carrier with the same bandwidth, but this is only an example, and each component carrier can have a different bandwidth. Furthermore, although each component carrier is shown as adjacent to each other on the frequency axis, the figure is shown in a logical concept, and each component carrier can be physically adjacent to each other or can be spaced apart.

[0138] Different center frequencies can be used for each component carrier. Furthermore, a common center frequency can be used for physically adjacent component carriers. Assuming in... Figure 8 In one embodiment, all component carriers are physically adjacent, and center frequency A can be used in all component carriers. Alternatively, assuming the component carriers are not physically adjacent, center frequencies A and B can be used in each component carrier.

[0139] When extending the total system bandwidth through carrier aggregation, the bandwidth used for communication with each user equipment (UE) can be defined on a component carrier basis. UE A can use 100MHz, which is the total system bandwidth, and performs communication using all five component carriers. UEs B1 through B5 can use only 20MHz bandwidth and perform communication using one component carrier. UEs C1 and C2 can use 40MHz bandwidth and each perform communication using two component carriers. The two component carriers can be logically / physically adjacent or not adjacent. Figure 8 In one embodiment, user equipment C1 uses two non-adjacent component carriers, and user equipment C2 uses two adjacent component carriers.

[0140] Figure 9 This is a schematic diagram used to explain single-carrier and multi-carrier communication. Specifically, Figure 9 (a) shows the single-carrier subframe structure and Figure 9 (b) shows the multi-carrier subframe structure.

[0141] refer to Figure 9 (a) In FDD mode, a general wireless communication system can perform data transmission or reception via a DL band and a corresponding UL band. In another specific embodiment, in TDD mode, the wireless communication system can divide a radio frame into UL time units and DL time units in the time domain, and perform data transmission or reception via the UL / DL time units. (See reference...) Figure 9 (b) Three 20MHz component carriers (CCs) can be aggregated into UL and DL respectively, thus supporting a bandwidth of 60MHz. Each CC can be adjacent to or not adjacent to each other in the frequency domain. Figure 9(b) illustrates a case where the bandwidth of the UL CC and DL CC are the same and symmetrical, but the bandwidth of each CC can be determined independently. Additionally, asymmetric carrier aggregation with different numbers of UL CCs and DL CCs is possible. DL / UL CCs assigned / configured to a specific user equipment via RRC can be referred to as the serving UL / DL CCs of that specific user equipment.

[0142] A base station can communicate with a user equipment (UE) by activating some or all of its serving CCs or by deactivating some CCs. The base station can change the CCs to be activated / deactivated, and can also change the number of CCs to be activated / deactivated. If the base station allocates CCs available to the UE as cell-specific or UE-specific, at least one of the allocated CCs is deactivated unless the UE's CC allocation is completely reconfigured or the UE is handover. A CC that is not deactivated by the UE is called the primary CC (PCC) or primary cell (PCell), and CCs that the base station can freely activate / deactivate are called secondary CCs (SCCs) or secondary cells (SCells).

[0143] Meanwhile, 3GPP NR uses the concept of cells to manage radio resources. A cell is defined by a combination of DL resources and UL resources (i.e., a combination of DL CC and UL CC). A cell can be configured with DL resources alone, or a combination of DL and UL resources. If carrier aggregation is supported, the link between the carrier frequencies of the DL resources (or DL ​​CC) and the UL resources (or UL CC) can be indicated via system information. The carrier frequency refers to the center frequency of each cell or CC. The cell corresponding to a PCC is called a PCell, and the cell corresponding to an SCC is called an SCell. The carrier corresponding to a PCell in the downlink is the DL PCC, and the carrier corresponding to a PCell in the uplink is the UL PCC. Similarly, the carrier corresponding to an SCell in the downlink is the DL SCC, and the carrier corresponding to an SCell in the uplink is the UL SCC. Depending on the capabilities of the user equipment, a serving cell can consist of one PCell and zero or more SCells. If the user equipment is in the RRC_CONNECTED state but not configured for carrier aggregation or does not support carrier aggregation, only one serving cell with a PCell configured exists.

[0144] As mentioned above, the term "cell" used in carrier aggregation differs from the term "cell" referring to a specific geographical area where communication services are provided by a single base station or antenna array. To distinguish between cells referring to a specific geographical area and cells in carrier aggregation, in this invention, a cell in carrier aggregation is referred to as a CC, and a cell representing a geographical area is referred to as a cell.

[0145] Figure 10This is a schematic diagram illustrating an example of cross-carrier scheduling technology. When cross-carrier scheduling is configured, the control channel transmitted via the first CC can use the Carrier Indicator Field (CIF) to schedule the data channel transmitted via either the first CC or the second CC. The CIF is included in the DCI. In other words, the scheduling cell is configured, and the DL license / UL license transmitted in the PDCCH area of ​​the scheduling cell schedules the PDSCH / PUSCH of the scheduled cell. That is, there is a search area for multiple component carriers within the PDCCH area of ​​the scheduling cell. The PCell is essentially the scheduling cell, and a specific SCell can be designated as the scheduling cell by the upper layer.

[0146] exist Figure 10 In this embodiment, it is assumed that three DL CCs are aggregated. Here, it is assumed that DL component carrier #0 is a DL PCC (or PCell), and that DL component carrier #1 and DL component carrier #2 are DL SCCs (or SCells). It is also assumed that the DL PCC is set as a PDCCH monitoring CC. If cross-carrier scheduling is not configured via UE-specific (or UE group-specific or cell-specific) higher-layer signaling, CIF is disabled, and according to the NR PDCCH rules, in the absence of CIF in each DL CC, only the PDCCH scheduling its own PDSCH can be transmitted (non-cross-carrier scheduling, self-carrier scheduling). On the other hand, if cross-carrier scheduling is configured via UE-specific (or UE group-specific or cell-specific) higher-layer signaling, CIF is enabled, and the PDCCH scheduling the PDSCH of another CC and the PDCCH scheduling the PDSCH of DL CC A in a specific CC can be transmitted using CIF (cross-carrier scheduling). On the other hand, PDCCH is not transmitted in other DL CCs. Therefore, depending on whether cross-carrier scheduling is configured for the user equipment, the user equipment receives the self-carrier-scheduled PDSCH by monitoring the PDCCH that does not include CIF, or receives the cross-carrier-scheduled PDSCH by monitoring the PDCCH that includes CIF.

[0147] at the same time, Figure 9 and 10 The diagram illustrates the subframe structure of a 3GPP LTE-A system, but the same or similar configuration can be applied to a 3GPP NR system. However, in a 3GPP NR system, Figure 9 and Figure 10 Subframes are replaced by time slots.

[0148] Figure 11 The illustration shows a code block group (CBG) configuration and its time-frequency resource mapping according to an embodiment of the present invention. More specifically, Figure 11 (a) The illustration includes an embodiment of a CBG configuration within a transport block (TB), and Figure 11(b) The diagram shows the time-frequency resource mapping of the corresponding CBG configuration.

[0149] Define the maximum supported length of the channel code. For example, the maximum supported length of the turbine code used in 3GPP LTE(-A) is 6144 bits. However, the length of the transport block (TB) transmitted in the PDSCH can be longer than 6144 bits. If the length of the TB is greater than the maximum supported length, the TB can be divided into code blocks (CBs) with a length of up to 6144 bits. Each CB is the unit in which channel compilation is performed. Additionally, several CBs can be bundled together to form a CBG for efficient retransmission. User equipment and base stations need information on how to configure CBGs.

[0150] The number of CBGs and CBs within a TB can be configured according to various embodiments. According to one embodiment, the number of available CBGs can be determined as a fixed value, or it can be configured by RRC configuration information between the base station and the user equipment. In this case, the number of CBs is determined based on the length of the TB, and the CBGs can be set according to the determined number information. According to another embodiment, the number of CBs that can be included in a CBG can be determined as a fixed value, or it can be configured by RRC configuration information between the base station and the user equipment. In this case, when the number of CBs is determined based on the length of the TB, the number of CBGs can be set according to information about the number of CBs in each CBG.

[0151] refer to Figure 11 In embodiment (a), a TB can be divided into 8 CBs. The 8 CBs can be further divided into 4 CBGs. The mapping relationship (or CBG configuration) between CBs and CBGs can be statically set between the base station and the user equipment, or semi-statically set using RRC configuration information. According to another embodiment, the mapping relationship can be established via dynamic signaling. When the user equipment receives a PDCCH sent by the base station, the user equipment can directly or indirectly identify the CB and CBG mapping relationship (or CBG configuration) through explicit and / or implicit information. A CBG may include only one CB, or it may include all CBs that make up a TB. For reference, the techniques proposed in the embodiments of the present invention can be applied regardless of the configuration of CBs and CBGs.

[0152] refer to Figure 11(b) Mapping the CBGs that make up a TB to the time-frequency resources for scheduling the PDSCH. According to an embodiment, each CBG can first be allocated to the frequency axis and then extended to the time axis. When a PDSCH consisting of a TB containing four CBGs is allocated to seven OFDM symbols, CBG0 can be transmitted via the first and second OFDM symbols, CBG1 via the second, third, and fourth OFDM symbols, CBG2 via the fourth, fifth, and sixth OFDM symbols, and CBG3 via the sixth and seventh OFDM symbols. The time-frequency mapping relationship between the CBGs and the PDSCH can be predetermined between the base station and the user equipment. However, Figure 11 The mapping relationship shown in (b) is used to explain the embodiments of the present invention, and the techniques proposed in the embodiments of the present invention can be applied, regardless of the time-frequency mapping relationship of CBG.

[0153] Figure 12 The illustration depicts a transmission process according to an embodiment of the present invention, in which a base station performs TB-based transmission or CBG-based transmission, and a user equipment responds by performing HARQ-ACK transmission. (Reference) Figure 12 The base station can configure a transmission scheme suitable for user equipment (UE) between TB-based and CBG-based transmissions. UE can send HARQ-ACK bits according to the transmission scheme configured by the base station via PUCCH or PUSCH. The base station can configure PDCCH to schedule PDSCHs to be sent to UE. PDCCH can schedule TB-based and / or CBG-based transmissions. For example, one TB or two TBs can be scheduled in the PDCCH. If one TB is scheduled, the UE should respond with a 1-bit HARQ-ACK. If two TBs are scheduled, two bits of HARQ-ACK should be responded with. To eliminate ambiguity between the base station and UE, a preset order can exist between each bit of the 2-bit HARQ-ACK and the two TBs. For reference, when the MIMO transmission rank or layer is low, one TB can be sent in one PDSCH. When the MIMO transmission rank or layer is high, two TBs can be sent in one PDSCH.

[0154] The User Equipment (UE) can send a 1-bit HARQ-ACK for each Data Point (TB) to notify the base station whether the reception of each TB was successful. To generate a HARQ-ACK for a TB, the UE can check for reception errors of the corresponding TB using TB-CRC. If the TB-CRC check for the TB is successful, the UE generates an ACK for the corresponding TB's HARQ-ACK. However, if a TB-CRC error occurs for the TB, the UE generates a NACK for the corresponding TB's HARQ-ACK. The UE sends the TB-based HARQ-ACK generated as described above to the base station. The base station retransmits the TB responding to the NACK from the TB-based HARQ-ACK received from the UE.

[0155] Additionally, the user equipment (UE) can send a 1-bit HARQ-ACK for each CBG to notify the base station whether the reception of each CBG was successful. To generate a HARQ-ACK for a CBG, the UE can decode all CBs included in the CBG and check for reception errors in each CB using CB-CRC. If the UE successfully receives all CBs comprising a CBG (i.e., when all CB-CRC checks are successful), the UE generates an ACK for the corresponding CBG's HARQ-ACK. However, if the UE fails to receive at least one CB comprising a CBG (i.e., at least one CB-CRC error occurs), the UE generates a NACK for the corresponding CBG's HARQ-ACK. The UE sends the CBG-based HARQ-ACK generated as described above to the base station. The base station retransmits the CBGs that responded to the NACK from the CBG-based HARQ-ACK received from the UE. According to an embodiment, the CB configuration of the retransmitted CBG can be the same as the CB configuration of the previously transmitted CBG. The length of the CBG-based HARQ-ACK bits sent by the user equipment to the base station can be determined based on the number of CBGs transmitted via PDSCH or the maximum number of CBGs configured by the RRC signal. Alternatively, the TB-based HARQ-ACK can be transmitted separately from the CBG-based HARQ-ACK, as in the embodiments described above. In this case, the TB-based HARQ-ACK can indicate whether the TB-CRC check was successful.

[0156] According to embodiments of the present invention, CBG-based HARQ-ACK feedback can be used for successful TB transmission. The base station can instruct the user equipment to send a CBG-based HARQ-ACK. In this case, a CBG-based HARQ-ACK retransmission scheme can be used. The CBG-based HARQ-ACK can be sent via PUCCH. Additionally, when UCI is configured to be transmitted via PUSCH, the CBG-based HARQ-ACK can be sent via the corresponding PUSCH. The configuration of HARQ-ACK resources in the PUCCH can be configured via RRC signals. Furthermore, the PDCCH of the PDSCH transmitted based on CBG can be used to indicate the actual transmitted HARQ-ACK resources. The user equipment can send a HARQ-ACK for successful reception of the transmitted CBG via a PUCCH resource indicated by the PDCCH in the PUCCH resources configured with RRC.

[0157] The base station can identify whether a user equipment (UE) has successfully received a CBG (CBG) sent to it through CBG-based HARQ-ACK feedback from the UE. That is, by providing HARQ-ACK feedback for each CBG received from the UE, the base station can identify CBGs that the UE has successfully received and those that the UE failed to receive. The base station can perform CBG retransmission based on the received CBG-based HARQ-ACK. More specifically, the base station can bundle and retransmit only CBGs that respond to HARQ-ACKs indicating failed reception within a TB (Base Transaction). In this case, CBGs that have already responded to successfully received HARQ-ACKs are excluded from the retransmission. The base station can schedule the retransmitted CBGs to a PDSCH (Power Distribution System) and send them to the UE.

[0158] The number of CBGs transmitted via PDSCH can vary during CBG retransmissions used to transmit a TB. Therefore, the UE needs to send a HARQ-ACK to indicate whether the reception of a CBG transmitted in the corresponding PDSCH was successful. However, the UE does not need to send HARQ-ACKs to the base station for CBGs that have already been acknowledged with an ACK but have not yet been retransmitted in the corresponding PDSCH. As mentioned above, the number of HARQ-ACK bits can be reduced based on the number of CBGs transmitted in PDSCH. This not only improves the reliability of HARQ-ACK but also allows unused HARQ-ACK resources to be reused for HARQ-ACKs of CBGs corresponding to other TBs or different TBs of the same UE, thereby reducing uplink control channel overhead. However, despite these advantages, the method of transmitting HARQ-ACK bits based on the number of CBGs transmitted in PDSCH may have disadvantages in the following two situations.

[0159] i) A NACK-to-ACK error may occur at the base station after the user equipment (UE) sends a PUCCH (or a PUSCH including HARQ-ACK) that sends a HARQ-ACK. In this case, the base station can determine that the CBG to be retransmitted was successfully sent and can send it without using the next PDSCH for retransmission. The UE expects to retransmit the CBG that was not received, but because the CBG was not sent via the next PDSCH, a NACK transmission for the corresponding CBG retransmission is required. However, because the CBG has not yet been sent via the next PDSCH for retransmission, the UE cannot send a HARQ-ACK for the corresponding CBG. Therefore, when a NACK-to-ACK error occurs due to the transmission of a PUCCH (or a PUSCH including HARQ-ACK) that sends a HARQ-ACK from the UE, a method is needed to mitigate this error.

[0160] ii) In CBG-based transmissions, the user equipment (UE) can determine whether CBG reception was successful based on the CRC success of the CBs included in the CBG. That is, when the CB-CRC of all CBs included in the CBG is successfully checked, the UE can send an ACK as a HARQ-ACK for the corresponding CBG. Conversely, when a CB-CRC error occurs even in one of the CBs included in the CBG, the UE can send a NACK as a HARQ-ACK for the corresponding CBG. However, the success of TB reception can be determined based on whether the TB-CRC attached to the TB is successfully checked. Therefore, the UE can determine that all CBGs have been successfully received and send an ACK as a HARQ-ACK for the corresponding CBG, but may fail to check the TB-CRC and thus fail to receive the TB. Therefore, a method to improve this situation is needed.

[0161] According to embodiments of the present invention, a backoff indicator can be used as a method to address the aforementioned problems that may arise when using a method that sends HARQ-ACK bits based on the number of CBGs transmitted in the PDSCH. The backoff indicator is an indicator for retransmitting all CBGs of a TB via the PDSCH (hereinafter referred to as the backoff mode). The user equipment can generate the backoff indicator according to the following embodiments and send it along with the HARQ-ACK via the allocated PUCCH resources. The backoff indicator can indicate either of two states. In embodiments of the present invention, the first state will be referred to as a "backoff mode request," and the second state will be referred to as a "non-backoff request." A "backoff mode request" is a state for requesting the retransmission of all CBGs of a TB, while a "non-backoff request" is a state in which retransmission of all CBGs is not required. According to yet another embodiment of the present invention, the backoff indicator can be used as a TB-based HARQ-ACK. Specific embodiments of TB-based HARQ-ACK will be described later.

[0162] According to an embodiment of the present invention, in a user equipment configured to operate based on CBG, only one CBG can be configured for a TB. That is, all CBs included in a TB can be configured as one CBG. In this case, the HARQ-ACK feedback sent by the user equipment can be determined based on the success of the TB-CRC check. That is, if the TB-CRC check is successful, the user equipment can send an ACK as a HARQ-ACK for the corresponding CBG. If the TB-CRC check fails, the user equipment can send a NACK as a HARQ-ACK for the corresponding CBG. In this case, whether to execute the fallback mode can be determined from the ACK / NACK for the CBG without an explicit transmission fallback indicator. More specifically, a user equipment that expects to operate in fallback mode can send a NACK as a HARQ-ACK for the CBG. When a NACK is received from the user equipment as a HARQ-ACK, the base station can determine that the fallback mode is necessary and can retransmit all CBGs of the corresponding TB via PDSCH.

[0163] According to another embodiment of the present invention, in a user equipment configured to operate based on CBGs, N CBGs (where N is a natural number greater than 1) can be configured for a TB. That is, a TB can consist of two or more CBGs. In this case, the method by which the user equipment sends the backoff indicator and HARQ-ACK is as follows.

[0164] First, N CBGs (i.e., all CBGs) for one TB can be transmitted in the PDSCH. In this case, the UE can determine whether the reception of each CBG was successful via CB-CRC and can send HARQ-ACK for the N CBGs via the previously configured or indicated PUCCH resources. When all CB-CRCs included in each CBG are successfully checked, the UE can send ACK as HARQ-ACK for the corresponding CBG. Otherwise, the UE can send NACK as HARQ-ACK for the corresponding CBG. HARQ-ACK for CBGs can be sent via HARQ-ACK in the PUCCH or PUSCH sent by the UE. The base station can bundle CBGs for which the UE has already responded with NACK and retransmit them via PDSCH. In this case, whether to execute fallback mode can be determined from the ACK / NACK for CBGs without an explicit transmission fallback indicator. More specifically, the UE expecting to operate in fallback mode can send NACK as HARQ-ACK for CBGs. When the base station receives a NACK from the user equipment as a HARQ-ACK for all CBGs, it can determine that the backoff mode is necessary and can retransmit all CBGs of the corresponding TB via PDSCH.

[0165] Table 4 shows the HARQ-ACK feedback that can be sent by the user equipment (UE) and its operation when N=2. If the UE's HARQ-ACK is [ACK ACK], the base station can determine that the UE has successfully received the TB. If the UE's HARQ-ACK is [ACK NACK], the base station can determine that the UE has successfully received the first CBG but failed to receive the second CBG. Therefore, the base station can retransmit the second CBG via PDSCH. If the UE's HARQ-ACK is [NACK ACK], the base station can determine that the UE has successfully received the second CBG but failed to receive the first CBG. Therefore, the base station can retransmit the first CBG via PDSCH. If the UE's HARQ-ACK is [NACK NACK], the base station can determine that the UE needs to use fallback mode. Therefore, the base station can bundle the first and second CBGs and retransmit them via PDSCH.

[0166] [Table 4]

[0167] HARQ-ACK Feedback Retransmit CBG [ACK ACK] CBG not retransmitted [ACK NACK] Retransmit CBG2 [NACK ACK] Retransmit CBG1 [NACK NACK] Retransmit CBG1 and CBG (rollback mode)

[0168] Next, for a natural number M less than N, M CBGs (i.e., some CBGs) of one TB can be sent via PDSCH. When sending some CBGs for one TB, the user equipment sends the backoff indicator and HARQ-ACK as follows. In each embodiment, the same or corresponding parts as in the previous embodiments will be omitted from the repeated description.

[0169] According to a first embodiment of the present invention, a user equipment (UE) can transmit M+1 bits of ACK / NACK bits and a 1-bit backoff indicator for each of M CBGs via HARQ-ACK resources. In this case, the 1-bit backoff indicator can be prioritized by the M-bit HARQ-ACK to determine whether to execute the backoff mode. The UE can determine whether the reception of each transmitted CBG was successful via CB-CRC. More specifically, since there is a possibility that up to N CBGs may be transmitted to the UE, PUCCH resources capable of accommodating N HARQ-ACK bits are allocated to the UE. The UE can transmit 1 to N HARQ-ACK bits via the corresponding resources. The UE can transmit (M+1) bits of feedback by binding the 1-bit backoff indicator with the M-bit HARQ-ACK in the HARQ-ACK resources. The base station can obtain the M-bit HARQ-ACK and 1-bit backoff indicator for the transmitted CBG by receiving the (M+1) bits of feedback via the PUCCH or PUCCH resources of the PUSCH transmitted from the UE.

[0170] Figure 13 The illustration shows an embodiment of the method for receiving HARQ-ACK feedback and backoff indicators. (Reference) Figure 13 The base station can determine whether a fallback mode is needed by assigning priority to a 1-bit fallback indicator using an M-bit HARQ-ACK. If a fallback mode is needed, the user equipment (UE) can send a fallback indicator to indicate a "fallback mode request"; otherwise, the UE can send a fallback indicator to indicate a "no fallback request". The base station checks the status indicated by the received fallback indicator. If the fallback indicator indicates a "fallback mode request", the base station can execute the fallback mode by ignoring ACK / NACK / DTX information such as the M-bit HARQ-ACK. That is, the base station can bundle all CBGs corresponding to the TB and retransmit them via PDSCH. If the fallback indicator indicates a "no fallback request", the base station can execute CBG retransmission based on the M-bit HARQ-ACK information. That is, the base station can bundle CBGs responding to NACK and retransmit them via PDSCH.

[0171] According to a second embodiment of the present invention, the user equipment may use the remaining (NM) bits of the N bits secured by the HARQ-ACK resource, excluding the M HARQ-ACK bits, as a backoff indicator. In this case, the (NM) bit backoff indicator can be prioritized by the M-bit HARQ-ACK to determine whether to execute the backoff mode. The user equipment may send N bits combining the ACK / NACK bits for each of the M CBGs and the (NM) bit backoff indicator via the HARQ-ACK resource. That is, the user equipment may send N bits of feedback by binding the (NM) bit backoff indicator together with the M-bit HARQ-ACK in the HARQ-ACK resource. The base station may obtain the M-bit HARQ-ACK and (MN) bit backoff indicator for the transmitted CBG by receiving the N bits of feedback via the PUCCH or PUSCH transmitted from the user equipment. The (MN) bit backoff indicator may indicate either a "backoff mode request" or a "non-backoff request" state. Because a (MN)-bit backoff indicator can consist of multiple bits, its transmission reliability can be higher than that of a 1-bit backoff indicator.

[0172] refer to Figure 13 The following description explains the method for receiving HARQ-ACK feedback and backoff indicators. The base station can determine whether backoff mode is needed by assigning priority to (NM)-bit backoff indicators via M-bit HARQ-ACK. If backoff mode is needed, the user equipment can send an (NM)-bit backoff indicator to indicate a "backoff mode request"; otherwise, the user equipment can send an (NM)-bit backoff indicator to indicate a "no backoff request". The base station checks which state the received backoff indicator indicates. If the backoff indicator indicates a "backoff mode request", the base station can execute backoff mode. If the backoff indicator indicates a "no backoff request", the base station can perform CBG retransmission based on the M-bit HARQ-ACK information. A specific implementation is described, for example, in the first embodiment.

[0173] Table 5 illustrates the backoff indicators and HARQ-ACK feedback that user equipment can send and their operation when N=3 and M=2. In this case, a TB consists of 3 CBGs, and the first and second CBGs, which are some of the CBGs used for a TB, can be sent via PDSCH.

[0174] [Table 5]

[0175]

[0176] Referring to Table 5, the base station can preferably check the back-off indicator using the HARQ-ACK bits. If the back-off indicator indicates "back-off mode request," the base station can always execute back-off mode. That is, the base station can retransmit all CBGs that make up the TB via PDSCH, namely, the first CBG, the second CBG, and the third CBG. If the back-off indicator indicates "non-back-off request," the base station can perform CBG retransmission based on the 2-bit HARQ-ACK information. That is, if the user equipment's HARQ-ACK is [ACK ACK], the base station can determine that the user equipment has successfully received both CBGs. If the user equipment's HARQ-ACK is [ACK NACK], the base station can determine that the user equipment has successfully received the first CBG but failed to receive the second CBG. Therefore, the base station can retransmit the second CBG via PDSCH. If the user equipment's HARQ-ACK is [NACK ACK], the base station can determine that the user equipment has successfully received the second CBG but failed to receive the first CBG. Therefore, the base station can retransmit the first CBG via PDSCH. If the user equipment's HARQ-ACK is [NACK NACK], the base station can determine that the user equipment failed to receive the first CBG and the second CBG. Therefore, the base station can bundle the first CBG and the second CBG and retransmit them via PDSCH.

[0177] According to a third embodiment of the present invention, the user equipment can transmit M+1 bits combining ACK / NACK bits for each of the M CBGs and a 1-bit backoff indicator via PUCCH resources. In this case, the 1-bit backoff indicator can be used to assign priority (or equivalent rank) to the M bits of HARQ-ACK to determine whether to execute the backoff mode. A specific implementation of the user equipment transmitting the 1-bit backoff indicator along with the M bits of HARQ-ACK via HARQ-ACK resources and receiving it by the base station is as described in the first embodiment.

[0178] Figure 14 This illustration shows another embodiment of the method for receiving HARQ-ACK feedback and backoff indicators. (See reference...) Figure 14The base station can determine whether a backoff mode is needed by assigning priority (or equivalent rank) to the M-bit HARQ-ACK using a 1-bit backoff indicator. That is, if all M-bit HARQ-ACKs are NACKs, the base station can determine whether a backoff mode is needed by checking the 1-bit backoff indicator. If a backoff mode is needed, the user equipment can send an M-bit HARQ-ACK to indicate all NACKs and a backoff indicator to indicate a "backoff mode request". In this case, the base station can bundle all CBGs corresponding to the TB and retransmit them via PDSCH. Otherwise, the base station can determine that a backoff mode is not needed. That is, if at least one ACK exists in the M-bit HARQ-ACKs, the base station may not execute a backoff mode regardless of the value indicated by the backoff indicator. In this case, the base station can bundle CBGs responding to NACKs based on the M-bit HARQ-ACK information and retransmit them via PDSCH.

[0179] According to a fourth embodiment of the present invention, the user equipment may use the remaining (NM) bits of the N bits secured by the HARQ-ACK resource, excluding the M HARQ-ACK bits, as a backoff indicator. In this case, the (NM)-bit backoff indicator can be used to assign priority (or equivalent rank) to the M-bit HARQ-ACK to determine whether to execute the backoff mode. The specific implementation of the user equipment sending the (NM)-bit backoff indicator together with the M-bit HARQ-ACK via the HARQ-ACK resource and the base station receiving them is as described above in the second embodiment.

[0180] refer to Figure 14 The following description explains the method for receiving HARQ-ACK feedback and the backoff indicator. The base station can determine whether backoff mode is needed by assigning priority (or equivalent rank) to the M-bit HARQ-ACK using an (NM)-bit backoff indicator. That is, if all M-bit HARQ-ACKs are NACKs, the base station can determine whether backoff mode is needed by checking the (NM)-bit backoff indicator. If backoff mode is needed, the user equipment can send an M-bit HARQ-ACK to indicate all NACKs and send an (NM)-bit backoff indicator to indicate a "backoff mode request". In this case, the base station can bundle all CBGs corresponding to the TB and retransmit them via PDSCH. Otherwise, the base station can determine that backoff mode is not needed. That is, if at least one ACK exists in the M-bit HARQ-ACKs, the base station may not execute backoff mode regardless of the value indicated by the backoff indicator. In this case, the base station can bundle CBGs responding to NACKs based on the information in the M-bit HARQ-ACKs and retransmit them via PDSCH.

[0181] Table 6 shows the backoff indicators and HARQ-ACK feedback that the user equipment can send and their operation when N=3 and M=2. In this case, a TB consists of 3 CBGs, and the first and second CBGs, which are some of the CBGs used for a TB, can be sent via PDSCH.

[0182] [Table 6]

[0183]

[0184] Referring to Table 6, if the 2-bit HARQ-ACK is [NACK NACK] and the backoff indicator indicates "backoff mode request," the base station can execute backoff mode. That is, the base station can retransmit all CBGs that make up the TB via PDSCH, namely, the first CBG, the second CBG, and the third CBG. In all other cases, the base station can determine that backoff mode is not needed. In this case, the base station can execute CBG retransmission based on the 2-bit HARQ-ACK information. That is, if the user equipment's HARQ-ACK is [ACK ACK], the base station can determine that the user equipment has successfully received both CBGs regardless of the value of the backoff indicator. If the user equipment's HARQ-ACK is [ACK NACK], the base station can determine that the user equipment has successfully received the first CBG, but not the second CBG, regardless of the value of the backoff indicator. Therefore, the base station can retransmit the second CBG via PDSCH. If the user equipment's HARQ-ACK is [NACK ACK], the base station can determine that the user equipment has successfully received the second CBG, but failed to receive the first CBG, regardless of the value of the backoff indicator. Therefore, the base station can retransmit the first CBG via PDSCH. If the user equipment's HARQ-ACK is [NACK NACK] and the backoff indicator indicates "non-backoff request," the base station can determine that the user equipment failed to receive the first and second CBGs. Therefore, the base station can bundle the first and second CBGs and retransmit them via PDSCH.

[0185] According to a fifth embodiment of the present invention, TB retransmission can be performed via higher-layer retransmission without an explicit backoff indicator. That is, the backoff mode for recovering erroneous transmissions at the physical layer can be omitted. According to the embodiment, for the base station and user equipment, there may be no explicit backoff indicator resources, and only HARQ-ACK resources for CBGs may exist. In this case, if the CBG to be retransmitted to the user equipment is not included in the PDSCH transmission, the user equipment can send an ACK as a HARQ-ACK for all CBGs of the PDSCH transmission, regardless of the success of the CB-CRC and TB-CRC of the PDSCH transmission. Thus, the user equipment identifies the reception failure of the corresponding TB, but unnecessary retransmissions can be prevented by sending ACKs for all CBGs. The failed TB can be recovered via higher-layer retransmission instead of retransmission via physical layer HARQ-ACK transmission.

[0186] Figure 15 The illustration shows an example of a user equipment sending a HARQ-ACK and fallback indicator for the CBG according to the above embodiment. Figure 15 In one embodiment, the base station can configure three CBGs (i.e., N=3) in a TB, and therefore can allocate PUCCH resources to the user equipment capable of sending a 3-bit HARQ-ACK. In the first PDSCH transmission, the base station sends CBG#1, CBG#2, and CBG#3. The user equipment successfully receives CBG#3 out of the three CBGs, but does not receive CBG#1 and CBG#2. Therefore, the user equipment can send [NACK NACK ACK] as a 3-bit HARQ-ACK for the first PDSCH transmission. In the second PDSCH transmission, the base station can retransmit only CBG#1 and CBG#2, except for CBG#3 which has already received an ACK from the user equipment. The user equipment can send a 3-bit HARQ-ACK in response to the second PDSCH transmission. In this case, the user equipment can use the first two bits of the 3-bit HARQ-ACK to indicate whether the retransmitted CBG#1 and CBG#2 have been received, and use the last bit corresponding to CBG#3 as a backoff indicator.

[0187] Figures 16 to 19 The illustration shows an additional embodiment where the user equipment sends HARQ-ACK feedback and backoff indicators for CBGs. According to an additional embodiment of the invention, the length of the HARQ-ACK payload sent by the user equipment can be configured based on the maximum number of CBGs configured by the RRC signal. Therefore, N CBG-based HARQ-ACK bits can be configured for the user equipment. In the following, in... Figures 16 to 19In this embodiment, the maximum number of CBGs configured by the RRC signal is N, and the number of CBGs included in the TB transmitted by the base station is M. In this case, the M bits in the N-bit HARQ-ACK can be a CBG-based HARQ-ACK indicating whether the reception of each CBG was successful (i.e., an M-bit CBG-based HARQ-ACK). Additionally, when M is less than N, the remaining NM bits in the N-bit HARQ-ACK can be a backoff indicator.

[0188] In embodiments of the present invention, the indication of whether a user equipment has successfully received a HARQ-ACK for each CBG sent via PDSCH is referred to as a CBG-based HARQ-ACK or a CBG-level HARQ-ACK. Additionally, as described above, in embodiments of the present invention, the backoff indicator can also be referred to as a TB-based HARQ-ACK. In embodiments of the present invention, the indication of whether a user equipment has successfully received a HARQ-ACK for each TB sent via PDSCH is referred to as a TB-based HARQ-ACK or a TB-level HARQ-ACK.

[0189] According to embodiments of the present invention, the (NM) bit back indicator can be configured in various ways. According to one embodiment, the (NM) bit back indicator can be configured as all ACKs or all NACKs. According to another embodiment, the (NM) bit back indicator can be configured by repeating a 1-bit TB-based HARQ-ACK with NM bits. According to yet another embodiment, the (NM) bit back indicator can be configured based on the value of an M-bit CBG-based HARQ-ACK. If M is a divisor of N, the (NM) bit back indicator can be configured by repeating the value of an M-bit CBG-based HARQ-ACK.

[0190] Table 7 illustrates an embodiment of configuring a 4-bit HARQ-ACK feedback when N=4 and M=1 to 4. First, when M=1, a 4-bit HARQ-ACK [b0 b0 b0 b0] can be configured by repeating HARQ-ACK b0 for CBG#0 four times. Next, when M=2, a 4-bit HARQ-ACK [b0 b1 b0b1] can be configured by repeating HARQ-ACK b0 for CBG#0 and HARQ-ACK b1 for CBG#1 twice. Next, when M=3, a 4-bit HARQ-ACK can be configured as [b0 b1 b2 x] using HARQ-ACK b0 for CBG#0, HARQ-ACK b1 for CBG#1, HARQ-ACK b2 for CBG#2, and x determined by the combination of b0, b1, and b2. According to the embodiment, x can be obtained by XORing b0, b1, and b2. According to another embodiment, x can be determined by the value of b0+b1+b2 (mod 2). Table 7 shows an embodiment of configuring N-bit HARQ-ACK feedback, and N-bit HARQ-ACK feedback can be configured by a combination of at least one of the above embodiments.

[0191] [Table 7]

[0192]

[0193] According to another embodiment of the invention, the user equipment can be configured in a transmission mode in which two TBs can be transmitted in one PDSCH. In this case, the user equipment can send HARQ-ACK feedback according to the length of the CBG-based HARQ-ACK payload for the two TBs. If each TB is configured with the maximum number of CBGs and the user equipment receives a PDSCH that schedules only one TB, the user equipment can generate a HARQ-ACK with a CBG-based HARQ-ACK payload length for both TBs by repeating the CBG-based HARQ-ACK for one TB.

[0194] For example, a user equipment (UE) can be configured in a transmission mode in which up to two TBs can be transmitted and one TB can include up to four CBGs. If only one TB is scheduled for the UE, an 8-bit HARQ-ACK [b0 b1 b2 b3b0b1 b2 b3] can be configured by repeating the CBG-based HARQ-ACK [b0 b1 b2 b3b0b1 b2 b3] twice for the four CBGs included in the TB. On the other hand, if two TBs are scheduled for the UE, an 8-bit HARQ-ACK [b0 b1 b2 b3 c0 c1 c2 c3] can be configured by combining the HARQ-ACK [b0 b1 b2 b3 c0 c1 c2 c3] for the four CBGs included in the first TB and the HARQ-ACK [c0c1 c2 c3] for the four CBGs included in the second TB. The UE can then send the configured HARQ-ACK to the base station.

[0195] Furthermore, even in a transmission mode where two TBs can be transmitted in a single PDSCH, the number M of CBGs contained in the TB transmitted by the base station can be less than N. In this case, a method for configuring the remaining NM bits in the N-bit HARQ-ACK, excluding the M bits, is the same as in the embodiment described above.

[0196] Additionally, according to an additional embodiment of the invention, CBG-based HARQ-ACK and backoff indicators (or TB-based HARQ-ACK) resources for CBG can be sent via different PUCCHs. Figures 16 to 19 The illustration shows an embodiment in which user equipment sends CBG-based HARQ-ACK and backoff indicators through different HARQ-ACK resources.

[0197] first, Figure 16 The illustration shows an embodiment of allocating different HARQ-ACK resources to CBG-based HARQ-ACK transmissions and backoff indicators (or TB-based HARQ-ACK transmissions). Reference Figure 16The base station can allocate two HARQ-ACK resources to the user equipment at different times. These two different HARQ-ACK resources can be used for the transmission of CBG-based HARQ-ACK and backoff indicators (or TB-based HARQ-ACK), respectively. According to embodiments of the present invention, the resources used for transmitting backoff indicators (or TB-based HARQ-ACK) can be configured to precede the resources used for transmitting CBG-based HARQ-ACK. For example, time slot n+k1 (i.e., resource A) and time slot n+k2 (i.e., resource B) can be allocated to the user equipment as HARQ-ACK resources for PDSCH received in time slot n (where k1 < k2). Among these resources, resource A in time slot n+k1 can be the resource used for transmitting backoff indicators (or TB-based HARQ-ACK), and resource B in time slot n+k2 can be the resource used for transmitting CBG-based HARQ-ACK. Meanwhile, the length of the CBG-based HARQ-ACK payload transmitted via resource B can be configured based on any one of the number of CBGs sent, the maximum number of CBGs configured by the RRC signal, or the number of CBGs that can be included in the corresponding TB.

[0198] Figure 17 The illustration shows an embodiment of sending CBG-based HARQ-ACK and backoff indicators (or TB-based HARQ-ACK) using different HARQ-ACK resources. According to... Figure 17 In one embodiment, the user equipment (UE) can selectively send only one of the CBG-based HARQ-ACK and the TB-based HARQ-ACK. More specifically, if all CBG-based HARQ-ACKs are ACKs or all NACKs when a UE configured for CBG-based communication sends HARQ-ACKs to the base station, the UE may send only the TB-based HARQ-ACKs and may not send the CBG-based HARQ-ACKs. On the other hand, if the CBG-based HARQ-ACKs include at least one ACK and at least one NACK, the UE may send only the CBG-based HARQ-ACKs and may not send the TB-based HARQ-ACKs.

[0199] User equipment can select one of two different HARQ-ACK resources based on the type of HARQ-ACK to be sent in CBG-based HARQ-ACK and the backoff indicator (i.e., TB-based HARQ-ACK), and send the corresponding HARQ-ACK through the selected resource. For example... Figure 17As shown in (a), when sending a TB-based HARQ-ACK, the user equipment can send the TB-based HARQ-ACK through time slot n+k1. In this case, the user equipment can send a CBG-based HARQ-ACK without using time slot n+k2. According to an embodiment, when a TB-CRC check is successful, the user equipment can send an ACK as a TB-based HARQ-ACK. Simultaneously, when all CB-CRC checks have been successfully performed but a TB-CRC error occurs, the user equipment can send a NACK as a TB-based HARQ-ACK. Furthermore, even when all CBG reception fails (i.e., when all CB-CRCs have failed), the user equipment can still send a NACK as a TB-based HARQ-ACK. Figure 17 As shown in (b), when sending a CBG-based HARQ-ACK, the user equipment can send the CBG-based HARQ-ACK through time slot n+k2. In this case, the user equipment can send a TB-based HARQ-ACK without using time slot n+k1.

[0200] exist Figure 17 In this embodiment, the base station operates as follows: The base station may expect the user equipment (UE) to transmit a TB-based HARQ-ACK via resource A in time slot n+k1. If the UE's TB-based HARQ-ACK is successfully received via resource A and the HARQ-ACK is ACK, the base station determines that the UE has successfully received the TB. If the UE's TB-based HARQ-ACK is successfully received via resource A and the HARQ-ACK is NACK, the base station determines that the UE has failed to receive all CBGs (or all CBs). Therefore, the base station may retransmit all CBGs (or all CBs). When the UE's TB-based HARQ-ACK is successfully received via resource A, the base station may determine that the UE has not used resource B (i.e., time slot n+k2). Therefore, when the UE's TB-based HARQ-ACK is transmitted via resource A, resource B may be used for other purposes. For example, resource B may be used for another user's HARQ-ACK transmission. On the other hand, if the UE's TB-based HARQ-ACK is not successfully received via resource A, the base station may determine that the UE has transmitted a CBG-based HARQ-ACK. Therefore, the base station can receive CBG-based HARQ-ACKs from user equipment via resource B in time slot n+k2. The base station can then perform retransmissions of CBGs that the user equipment failed to receive based on the CBG-based HARQ-ACKs.

[0201] Figure 18The illustration shows another embodiment of sending CBG-based HARQ-ACK and backoff indicators (or TB-based HARQ-ACK) through different HARQ-ACK resources. According to... Figure 18 In one embodiment, the user equipment may send either only a TB-based HARQ-ACK or both a CBG-based HARQ-ACK and a TB-based HARQ-ACK, depending on whether all CBGs have been successfully received.

[0202] like Figure 18 As shown in (a), when the user equipment successfully receives all CBGs and successfully checks the TB-CRC, the user equipment can send an ACK as a TB-based HARQ-ACK through time slot n+k1. In this case, the user equipment can choose not to send a CBG-based HARQ-ACK through time slot n+k2. However, as... Figure 18 As shown in (b), when the user equipment fails to receive at least one CBG or a TB-CRC error occurs, the user equipment can send a NACK as a TB-based HARQ-ACK through time slot n+k1. In this case, the user equipment can send a CBG-based HARQ-ACK through time slot n+k2.

[0203] exist Figure 18 In this embodiment, the base station operates as follows: The base station always expects the user equipment (UE) to perform a TB-based HARQ-ACK transmission via resource A in time slot n+k1. If the TB-based HARQ-ACK received from the UE via resource A is ACK, the base station determines that the UE has successfully received the TB. In this case, the base station can determine that the UE does not use resource B (i.e., time slot n+k2). Therefore, when the UE sends a TB-based HARQ-ACK via resource A, resource B can be used for other purposes. For example, resource B can be used for another user's HARQ-ACK transmission. If the UE successfully receives a TB-based HARQ-ACK via resource A and the HARQ-ACK is NACK (or DTX), the base station determines that the UE has failed to receive at least one CBG. In this case, the base station receives the UE's CBG-based HARQ-ACK via resource B. The base station can perform retransmission of the CBG that the UE failed to receive based on the CBG-based HARQ-ACK.

[0204] According to another embodiment of the present invention, even when the TB-based HARQ-ACK is ACK, the TB-based HARQ-ACK and the CBG-based HARQ-ACK of the user equipment can be sent together. The base station can receive the TB-based HARQ-ACK and the CBG-based HARQ-ACK through resource A and resource B respectively, and determine the success of the user equipment reception by using the received HARQ-ACK. For example, if the TB-based HARQ-ACK is ACK and all CBG-based HARQ ACKs are ACKs, the base station determines that the user equipment has successfully received TB. However, if the TB-based HARQ-ACK is ACK and not all CBG-based HARQ ACKs are ACKs, the base station performs CBG-based retransmission based on the CBG-based HARQ-ACK. As another method, if the TB-based HARQ-ACK is ACK, the base station can determine that the user equipment has successfully received TB, regardless of the value of the CBG-based HARQ-ACK.

[0205] If a CBG-based HARQ-ACK is not successfully received via resource B even though the TB-based HARQ-ACK is NACK, the base station can determine that the user equipment failed to receive all CBGs and can retransmit all CBGs. According to another embodiment, if a CBG-based HARQ-ACK is not successfully received via resource B even though the TB-based HARQ-ACK is NACK, the base station can consider that an ACK-to-NACK error has occurred in the TB-based HARQ-ACK and can determine that the user equipment has successfully received the TB.

[0206] Furthermore, if the TB-based HARQ-ACK is NACK and all CBG-based HARQ-ACKs are ACK, the base station can retransmit all CBGs assuming the user equipment failed to receive them. According to another embodiment, if the TB-based HARQ-ACK is NACK and all CBG-based HARQ-ACKs are ACK, the base station can assume that an ACK-to-NACK error has occurred in the TB-based HARQ-ACK and can determine that the user equipment has successfully received the TB.

[0207] Figure 19The illustration shows an embodiment where a user equipment (UE) receives a PDCCH scheduled for retransmission of the corresponding TB between a TB-based HARQ-ACK transmission and a CBG-based HARQ-ACK transmission. More specifically, when a UE transmits a TB-based HARQ-ACK via resource A in time slot n+k1 and a CBG-based HARQ-ACK via resource B in time slot n+k2, it can receive the PDCCH for the scheduled TB retransmission in time slot n+k3, which precedes time slot n+k2 (i.e., k3 < k2). In this case, the UE can avoid transmitting the CBG-based HARQ-ACK via time slot n+k2. Thus, when the base station transmits the PDCCH for scheduled TB retransmissions before time slot n+k2, which is used for transmitting CBG-based HARQ-ACKs, resource B in time slot n+k2 can be used for other purposes. For example, resource B can be used for another user's HARQ-ACK transmission.

[0208] According to embodiments of the present invention, a base station can indicate information about resource A in time slot n+k1 and resource B in time slot n+k2 to a user equipment in various ways. According to one embodiment, the base station can independently indicate offsets k1 and k2 via a DCI. According to another embodiment, the base station can pre-notify or fix the difference between offsets k1 and k2 to the user equipment and indicate only one of offsets k1 or k2 via the DCI. The user equipment can obtain the values ​​of offsets k1 and k2 by using either offset indicated by the DCI and the previously known (or fixed) offset difference. In this case, the smaller of the obtained offsets can be used as the offset for TB-based HARQ-ACK transmission, and the larger of the offsets can be used as the offset for CBG-based HARQ-ACK transmission.

[0209] If HARQ-ACK multiplexing is configured for the user equipment, the TB-based HARQ-ACK transmitted via resource A in time slot n+k1 in the above embodiments can be multiplexed with TB-based HARQ-ACKs for one or more TBs. Additionally, the CBG-based HARQ-ACK transmitted via resource B in time slot n+k2 in the above embodiments can be multiplexed with CBG-based HARQ-ACKs for one or more TBs. According to the embodiments, a CBG-based HARQ-ACK transmitted via resource B can be generated by multiplexing the CBG-based HARQ-ACK bits for a TB where NACK is transmitted as a TB-based HARQ-ACK. That is, for a TB where ACK is transmitted as a TB-based HARQ-ACK transmitted via resource A, no CBG-based HARQ-ACK transmission is performed via resource B.

[0210] Furthermore, while the above embodiments describe resources based on time slots, the present invention is not limited thereto. That is, in cases such as short PUCCH transmissions, the time slots in the above embodiments can be replaced by OFDM symbols. In this case, OFDM symbol n+k1 and / or ODFM symbol n+k2 can be OFDM symbols that begin with the PUCCH.

[0211] Furthermore, in the above embodiments, it is assumed that k1 < k2. However, according to another embodiment of the present invention, offsets k1 and k2 can be set to the same value (i.e., k = k1 = k2). That is, HARQ-ACK resources of the same duration can be allocated for the transmission of TB-based HARQ-ACK and CBG-based HARQ-ACK. When the user equipment is configured in a transmission mode that can send two TBs in one PDSCH, the user equipment can perform HARQ-ACK transmission by selecting one of resources A and resource B configured in the same time slot n+k. According to an embodiment, if the HARQ-ACKs for two TBs sent through one PDSCH are both ACKs, the user equipment can send [ACK ACK] as a TB-based HARQ-ACK through resource A in time slot n+k. In this case, the user equipment may not use resource B in time slot n+k. If not all HARQ-ACKs for two TBs transmitted via a single PDSCH are ACKs, the UE can transmit a CBG-based HARQ-ACK for a CBG included in both TBs via resource B in slot n+k. In this case, the UE may not need to use resource A in slot n+k.

[0212] According to another embodiment of the present invention, when multiple TB-based HARQ-ACKs are multiplexed, a compressed CBG-based HARQ-ACK can be used to reduce the payload length. That is, the compressed CBG-based HARQ-ACK can be used by reducing the payload length in the original CBG-based HARQ-ACK. The user equipment generates the compressed CBG-based HARQ-ACK from the original CBG-based HARQ-ACK according to predetermined rules and sends the compressed CBG-based HARQ-ACK to the base station.

[0213] The first embodiment for generating compressed CBG-based HARQ-ACK is as follows. The base station can select the desired frequently occurring state from the entire CBG-based HARQ-ACK state for a TB, allowing the user equipment to signal this state. Here, the CBG-based HARQ-ACK state refers to the possible bit combinations of the original CBG-based HARQ-ACK. That is, a 4-bit CBG-based HARQ-ACK can have a total of 16 states, namely, [ACK ACK ACK ACK ACKACK] to [NACK NACK NACK NACK]. The base station can select P states from the original CBG-based HARQ-ACK states as described above. That is, when the total number of TBs transmitted via PDSCH is I, the original CBG-based HARQ-ACK state of the i-th TB can be mapped to the p-th state among the P states. i In this state, the user equipment is represented by the following equation: a total of I TB multiplied by the mapped p. i To obtain U, convert U to a binary value to obtain the compressed CBG-based HARQ-ACK for the entire TB.

[0214]

[0215] The base station receives compressed CBG-based HARQ-ACK from the user equipment and converts the compressed CBG-based HARQ-ACK into P symbol values ​​to obtain the mapped CBG-based HARQ-ACK state information p for each TB. i .

[0216] According to an embodiment, the value of P selected by the base station and information on P types of CBG-based HARQ-ACK states can be configured via an RRC signal sent by the base station to the user equipment. According to another embodiment, the value of P can be determined based on at least one of the capacity of PUCCHs that the user equipment can transmit and the number of TBs (or PDSCHs) that the user equipment needs to transmit. Furthermore, to determine the P types of CBG-based HARQ-ACK states, the entire CBG-based HARQ-ACK state can be pre-arranged according to a preset order. According to an embodiment, the preset order can be determined based on the frequency of occurrence of each state in the entire CBG-based HARQ-ACK state. For example, the CBG-based HARQ-ACK state indicating a reception error of an adjacent CBG can be determined in a higher order than the CBG-based HARQ-ACK state indicating a reception error of a non-adjacent CBG. The P states in the entire CBG-based HARQ-ACK state can be selected based on a preset order.

[0217] Table 8 illustrates an embodiment for determining P types of CBG-based HARQ-ACK states. In the embodiment in Table 8, P states are determined from a total of 16 original CBG-based HARQ-ACK states based on 4 CBG-based HARQ-ACK bits. Here, the information of the P types of CBG-based HARQ-ACK states selected when P is 2, 4, 6, 9, 11, 14, or 16 is illustrated.

[0218] [Table 8]

[0219]

[0220] Each of the selected P states can be indexed as the p-th state based on a preset order. i There are several states. As mentioned above, the original CBG-based HARQ-ACK state of each TB can be mapped to the p-th state among P states. i There are several states. When the number of original CBG-based HARQ-ACK states is N, a mapping from N to P can be performed. According to an embodiment of the present invention, the original CBG-based HARQ-ACK states can be mapped to the p-th state based on the NACK bits of the original states. i A state. That is, even in the p-th state of the mapping. i In a CBG-based HARQ-ACK state, bits that were NACK in the original CBG-based HARQ-ACK state will become NACK. For example, when the second bit is NACK (i.e., 0) in the original CBG-based HARQ-ACK state, the original state can be mapped to one of the states where the second bit is NACK (i.e.,

[0000] ,

[0001] ,

[0010] ,

[0011] ,

[1000] ,

[1001] ,

[1010] , and

[1011] ).

[0221] A second embodiment for generating compressed CBG-based HARQ-ACK is as follows. The maximum number of CBGs configured by the RRC signal is N, and the number of CBGs included in the TB transmitted by the base station is M. In this case, the M bits in the N-bit HARQ-ACK can be a CBG-based HARQ-ACK indicating whether the reception of each CBG was successful (i.e., an M-bit CBG-based HARQ-ACK). The base station can configure the length of the original CBG-based HARQ-ACK payload for one TB based on the maximum number of CBGs configured by the RRC signal. That is, the original CBG-based HARQ-ACK for one TB can consist of N bits. In this case, the original CBG-based HARQ-ACK can consist of [b0, b1, ..., b...]. M-1 ,X0,X1,...,XN-M-1 The original CBG-based HARQ-ACK can be represented by an M-bit CBG-based HARQ-ACK [b0, b1, ..., b]. M-1 ] and the remaining NM bits [X0, X1, ..., X N-M-1 Composed of ] In this case, X m It can be configured with a fixed value (e.g., ACK or NACK), or it can be configured based on an M-bit CBG-based HARQ-ACK value. The specific method is the same as in the embodiments described above.

[0222] To reduce the length of the HARQ-ACK payload, the base station can instruct the user equipment (UE) to use a compressed CBG-based HARQ-ACK. The base station can transmit this instruction via RRC signals or PDCCH. When the UE receives the instruction to use a compressed CBG-based HARQ-ACK, it can reduce the original N-bit CBG-based HARQ-ACK to a compressed L-bit CBG-based HARQ-ACK.

[0223] If L is greater than or equal to M, then the compressed CBG-based HARQ-ACK can be derived from [b0, b1, ..., b M-1 ,Y0,Y1,...,Y L-M-1 It consists of [b0, b1, ..., b] bits. That is, the compressed CBG-based HARQ-ACK can be composed of M bits of CBG-based HARQ-ACK [b0, b1, ..., b]. M-1 ] and the remaining LM bits [Y1,...,Y L-M-1 Therefore, the M-bit CBG-based HARQ-ACK is included as is in the compressed CBG-based HARQ-ACK, and only the remaining bits are reduced from NM to LM. That is, the M-bit CBG-based HARQ-ACK can be retained in the compressed CBG-based HARQ-ACK. In this case, Y m It can be configured with a fixed value (e.g., ACK or NACK), or it can be configured based on an M-bit CBG-based HARQ-ACK value.

[0224] If L is less than M, then the compressed CBG-based HARQ-ACK can be derived from [a0, a1, ..., a M-1 This can be achieved by combining the M bits of the original CBG-based HARQ-ACK (excluding the remaining NM bits) into a CBG-based HARQ-ACK [b0, b1, ..., b]. M-1At least a portion of ] is used to generate a compressed CBG-based HARQ-ACK. According to an embodiment, in the compressed CBG-based HARQ-ACK [a0,a1,...,a...], at least a portion of ] is used to generate a compressed CBG-based HARQ-ACK. M-1 In the context of b k*w ,b k*w+1 ,...,b (k+1)*w-1 When all are 1 (i.e., ACK), a from k=0 to L-2 k It is 1 (i.e., ACK). Furthermore, when b k*w ,b k*w+1 ,...,b M-1 When all are 1 (i.e., ACK), a = L-1 k If the value is 1 (i.e., ACK), then the value is 0 (i.e., NACK). Here, w = floor(M / L).

[0225] For example, we can assume N = 8 and M = 4, and that the remaining NM bits (i.e., 4 bits) are always sent as 0 (i.e., NACK). Additionally, we can assume the original CBG-based HARQ-ACK is [10110000]. When a 4-bit compressed CBG-based HARQ-ACK is generated from the original CBG-based HARQ-ACK, the compressed CBG-based HARQ-ACK becomes

[1011] . That is, even if the payload length is reduced to 4 bits, 4 bits of the CBG-based HARQ-ACK

[1011] can be retained in the compressed CBG-based HARQ-ACK. On the other hand, when a 2-bit compressed CBG-based HARQ-ACK is generated from the original CBG-based HARQ-ACK, the compressed CBG-based HARQ-ACK becomes

[01] . In this case, 4 bits of the CBG-based HARQ-ACK

[1011] are not retained in the compressed CBG-based HARQ-ACK. Compressed CBG-based HARQ-ACK

[01] can be generated by using 2 bits to bind 4 bits of CBG-based HARQ-ACK

[1011] .

[0226] In the following embodiments, transmission is assumed to be on a component carrier basis. In embodiments of the invention, a component carrier can be replaced by the term cell. In embodiments of the invention, for ease of description, transmission using carrier aggregation is described. However, in a TDD system using carrier aggregation, a component carrier can refer to all component carriers in a subframe (or time slot) where HARQ-ACK is multiplexed. A user equipment can receive a PDSCH in one or more component carriers and generate a HARQ-ACK bit sequence in response. The HARQ-ACK bit sequence can be generated by combining the HARQ-ACK bits for each of the one or more component carriers. In embodiments of the invention, the HARQ-ACK bit sequence can be replaced by terms such as HARQ-ACK information bits, HARQ-ACK codebook, HARQ-ACK codeword, HARQ-ACK payload, etc. In the following embodiments, the HARQ-ACK bit sequence used for TB-based transmission (or PDSCH) can be referred to as the TB-based HARQ-ACK bit sequence, and the HARQ-ACK bit sequence used for CBG-based transmission (or PDSCH) can be referred to as the CBG-based HARQ-ACK bit sequence.

[0227] When using carrier aggregation, each component carrier can be configured with different transmission schemes. That is, one TB transmission can be configured in the first component carrier, and two TB transmissions can be configured in the second component carrier. Furthermore, in 3GPP NR systems, in addition to TB-based transmissions as described above, CBG-based transmissions are also supported. Therefore, TB-based transmissions can be configured in the first component carrier, and CBG-based transmissions can be configured in the second component carrier.

[0228] Simultaneously, the user equipment (UE) monitors the PDCCH in specific component carriers according to the scheme configured for the UE in its own carrier scheduling and cross-carrier scheduling, and receives the PDSCH based on the information in the PDCCH. Additionally, the UE transmits HARQ-ACK for the TB transmitted via PDSCH on each component carrier via PUCCH (or PUSCH). However, the UE may fail to decode the PDCCH scheduled for some component carriers configured by the base station (i.e., DTX occurs). In this case, excluding the HARQ-ACK for the corresponding component carrier, the UE can transmit only the HARQ-ACK for the successfully decoded component carrier via PUCCH (or PUSCH). However, when the UE excludes the transmission of HARQ-ACK for some component carriers, errors may occur in the HARQ-ACK feedback interpretation between the base station and the UE. To address this issue, LTE-A Release 13 uses a method that uses the Downlink Allocation Index (DAI) to detect DTX.

[0229] Figure 20 This illustration shows an example of a downlink allocation index (DAI) value mapped to each component carrier. (Reference) Figure 20 The PDCCH that schedules each PDSCH includes a counter-DAI and a total-DAI. The counter-DAI represents the cumulative number of PDSCHs scheduled from the first component carrier (i.e., component carrier #0) to the current component carrier. The total-DAI represents the total number of PDSCHs scheduled across all component carriers. If the counter-DAI field consists of A bits, the value of counter-DAI is between 0 and 2. A Between *n-1 (where n is a natural number). If the number of PDSCHes scheduled from the first component carrier to the current component carrier is C, then the value of the counter -DAI can be set to (C-1) mod 2. A Similarly, if the total-DAI field consists of B bits, then the value of total-DAI is between 0 and 2. B The value is between *m-1 (where m is a natural number). If the total number of PDSCHs scheduled for the entire component carrier is T, then the total -DAI value can be set to (T-1) mod 2. B User equipment can identify the order in which PDSCHs scheduled by the corresponding PDCCHs are sent by decoding the PDCCH. In this case, the user equipment can send the HARQ-ACK of the PDSCHs in the order in which the corresponding PDSCHs are sent.

[0230] refer to Figure 20The base station can transmit PDSCHs via component carriers #0, #1, #3, #4, #5, and #7 to user equipment that can use up to eight component carriers through aggregation. Since the total number of PDSCHs scheduled for component carriers is 6, the total -DAI value is set to 5. Therefore, the (counter-DAI, total -DAI) values ​​for component carriers #0, #1, #3, #4, #5, and #7 are (0, 5), (1, 5), (2, 5), (3, 5), (4, 5), and (5, 5), respectively. When decoding of a PDCCH transmitted on component carrier #3 fails, the user equipment can identify a PDCCH reception (and the corresponding PDSCH reception) failure based on the counter-DAI values ​​of the PDCCH transmitted on component carrier #1 and the PDCCH transmitted on component carrier #4. Additionally, when decoding of a PDCCH transmitted on component carrier #7 fails, the user equipment can identify that a PDSCH scheduled after component carrier #5 was not successfully received based on the counter -DAI value and total -DAI value of the PDCCH transmitted on component carrier #5.

[0231] By using the DAI described above, the user equipment can identify the order of successfully received PDSCHs and the order of unreceived PDSCHs. However, the user equipment cannot identify the number of TBs included in the unreceived PDSCHs, and therefore cannot determine the HARQ-ACK bit sequence. To address this issue, two methods can be used. The first method is to apply spatial bundling to all PDSCHs. In other words, a 2-bit HARQ-ACK for a PDSCH containing two TBs can be bundled to generate a 1-bit HARQ-ACK. This method has no additional UCI overhead, but may degrade transmission performance. The second method does not apply spatial bundling, but instead assumes that all PDSCHs contain two TBs. In other words, in this method, even for a PDSCH containing 1 TB, a 2-bit HARQ-ACK is sent. This method has the disadvantage of generating additional UCI overhead.

[0232] Simultaneously, as mentioned above, both TB-based and CBG-based transmissions are supported in the 3GPP NR system. When a user equipment (UE) is configured to multiplex and transmit HARQ-ACK bits for multiple component carriers, the base station can inform the UE whether CBG-based transmission is possible for each component carrier. However, TB-based transmissions can also be performed on component carriers configured for CBG-based transmissions. Therefore, a UE can expect TB-based transmissions only on a specific component carrier, and can also expect both TB-based and CBG-based transmissions on another specific component carrier. Only after successfully receiving all PDCCHs scheduled for each component carrier can the UE determine the sequence of HARQ-ACK bits to transmit on the uplink.

[0233] To prevent errors in determining and interpreting the HARQ-ACK bit sequence between the base station and the user equipment, the DAI described above can be used according to embodiments of the present invention. Assuming that N HARQ-ACK bits are required in response to CBG-based transmission, the user equipment and the base station can use the following three methods to prevent possible errors in interpreting the HARQ-ACK bit sequence when decoding of the CBG fails.

[0234] According to the first method, when the base station configures CBG-based transmissions to the user equipment in at least one component carrier using carrier aggregation, it can be assumed that CBG-based transmissions are performed on all PDSCHs scheduled to the user equipment. That is, even when the base station performs TB-based transmissions to the user equipment in a specific component carrier, the user equipment can still feed back N-bit HARQ-ACK. Here, N can be the maximum number of CBGs configured for each TB for the user equipment. However, in the case of the first method, there is a drawback of excessive PUCCH overhead. For example, if N=4, increasing the 1-bit HARQ-ACK to 4 bits can result in a maximum overhead of 300%.

[0235] According to the second method, when the base station configures CBG-based transmission to the user equipment in at least one component carrier using carrier aggregation, it can be assumed that TB-based transmission is performed on all PDSCHs scheduled to the user equipment. In this case, the user equipment can be fixed to feed back 1-bit or 2-bit HARQ-ACK in response to the PDSCH. However, in the second method, even if the user equipment is configured for CBG-based transmission from the base station and actually performs CBG-based transmission, the HARQ-ACK feedback information based on CBG-based transmission cannot be used, and therefore the performance gain of CBG-based transmission cannot be obtained.

[0236] According to the third method, when the base station configures whether to perform CBG-based transmissions to the user equipment (UE) for each component carrier during carrier aggregation, it can be assumed that CBG-based transmissions or TB-based transmissions are performed in the PDSCH scheduled for the UE, depending on whether the DCI of the corresponding component carrier and the PDSCH is configured. That is, when the base station configures CBG-based transmissions to the UE in a specific component carrier, even if the base station performs TB-based transmissions to the UE in that specific component carrier, the UE can still feed back an N-bit HARQ-ACK. Here, N can be the maximum number of CBGs configured for each TB for the UE. If the base station does not configure CBG-based transmissions to the UE in a specific component carrier, the UE can be fixed to feed back 1-bit or 2-bit HARQ-ACK by assuming that TB-based transmissions are performed on the PDSCH scheduled for the specific component carrier.

[0237] As described above, when both TB-based and CBG-based transmissions are configured for the user equipment using HARQ-ACK multiplexing, a signaling scheme to prevent misinterpretation of the HARQ-ACK bit sequence between the base station and the user equipment can be provided. According to embodiments of the invention, the user equipment can receive a PDCCH indicating PDSCH scheduling information for each of one or more component carriers. Additionally, the user equipment can receive a DCI via the PDCCH. In this case, CBG-based transmissions can be configured in at least one of the one or more component carriers. Furthermore, at least one TB-based transmission and at least one CBG-based transmission can be configured in one or more component carriers. The user equipment can identify the transmission scheme in each component carrier based on the DCI format. In this case, the transmission scheme is either TB-based or CBG-based. Simultaneously, the user equipment can receive a DAI via the PDCCH. The DAI includes the counter-DAI and total-DAI as described above.

[0238] User equipment (UE) receives the PDSCH of each component carrier in one or more component carriers based on the PDCCH scheduling information, and generates a HARQ-ACK bit sequence in response to receiving the PDSCH of each component carrier. In this case, UE generates the HARQ-ACK bit sequence with reference to DAI. The HARQ-ACK bit sequence includes at least one of a HARQ-ACK bit sequence for TB-based transmission (i.e., TB-based HARQ-ACK bit sequence) and a HARQ-ACK bit sequence for CBG-based transmission (i.e., CBG-based HARQ-ACK bit sequence). According to embodiments of the present invention, DAI can be applied to the TB-based HARQ-ACK bit sequence and the CBG-based HARQ-ACK bit sequence respectively. Furthermore, within the HARQ-ACK bit sequence, the TB-based HARQ-ACK bit sequence may precede the CBG-based HARQ-ACK bit sequence.

[0239] User equipment can generate HARQ-ACK bit sequences for one or more cells based on the identified transmission scheme for each cell. Specifically, it can generate both TB-based and CBG-based HARQ-ACK bit sequences within the HARQ-ACK bit sequence. In this case, one HARQ-ACK bit is generated for each TB in the TB-based HARQ-ACK bit sequence, and N HARQ-ACK bits are generated for each TB in the CBG-based HARQ-ACK bit sequence. That is, the HARQ-ACK bits for CBG-based PDSCH are configured to have N bits equally for each TB, regardless of the actual number of CBGs scheduled and transmitted in the PDSCH.

[0240] According to an embodiment of the invention, N may be the maximum number of CBGs configured for each TB for the user equipment. According to another embodiment, N may be a value configured by the base station for HARQ-ACK multiplexing. According to yet another embodiment, if the number M of CBGs transmitted via a specific component carrier configured for CBG-based transmission in one or more component carriers is less than N, the HARQ-ACK bits for the specific component carrier can be configured by repeating the HARQ-ACK bits for the transmitted CBGs. Furthermore, if the number M of CBGs transmitted via a specific component carrier configured for CBG-based transmission in one or more component carriers is less than N, the HARQ-ACK bits for the specific component carrier may consist of M HARQ-ACK bits for the transmitted CBGs and NM ACK bits. The user equipment transmits the HARQ-ACK bit sequence generated in this manner to the base station.

[0241] When a user equipment receives a PDCCH, it can identify whether a TB-based or CBG-based transmission is applied to the PDSCH scheduled by the PDCCH. The user equipment can identify the transmission scheme in each component carrier (i.e., PDSCH) based on the DCI information received via the PDCCH. For example, transmission scheme information can be signaled by an explicit 1-bit in the DCI, or inferred from a combination of other information included in the DCI. Additionally, the transmission scheme in each component carrier can be identified based on the DCI format. Different DCI formats can be used for different transmission schemes. Different DCI formats may have different amounts of information included in the DCI. That is, different DCI formats can have different DCI payload lengths. Furthermore, CRC can be scrambled with different RNTIs in different DCI formats. Additionally, when a PDCCH for scheduling CBG-based PDSCHs is received, the user equipment can identify which CBGs within the entire CBG are included in the PDSCH using the information specified in the DCI.

[0242] In the following description, specific embodiments of generating a HARQ-ACK bit sequence in response to receiving a PDSCH will be described with reference to each accompanying drawing. In each embodiment, it is assumed that a CBG-based transmission is configured in at least one of one or more component carriers (i.e., a cell). For example, at least one TB-based transmission and at least one CBG-based transmission may be configured in one or more component carriers. Additionally, in the embodiments of each drawing, portions identical or corresponding to those in the preceding drawings will be omitted. In embodiments of the invention, for ease of description, it is assumed that the value of each index or counter is incremented by 1 starting from 0. However, embodiments of the invention are not limited to this, and the index or counter value may be incremented by 1 starting from a predetermined value (e.g., 1).

[0243] Figure 21 and Figure 22The illustration shows a DAI signaling method and a HARQ-ACK bit sequence generation method based on the DAI signaling method according to a first embodiment of the present invention. According to embodiments of the present invention, DAI can be applied to both TB-based and CBG-based HARQ-ACK bit sequences. Therefore, the base station generates independent counter-DAI and total-DAI values ​​for each transmission scheme. The base station transmits the counter-DAI and total-DAI values ​​according to the PDSCH transmission scheme by using the counter-DAI field and total-DAI field of the PDCCH that schedules the PDSCH. The user equipment receives the DCI through the PDCCH sent by the base station, distinguishes the transmission scheme (i.e., TB-based transmission or CBG-based transmission) based on the information in the DCI, and receives the DAI corresponding to that transmission scheme. The user equipment can refer to the received DAI to generate the HARQ-ACK bit sequence for the corresponding transmission scheme. In this case, the user equipment can interpret the counter-DAI and total-DAI received through the PDCCH as the counter-DAI and total-DAI for the transmission scheme of the PDSCH scheduled by the PDCCH. Table 9 illustrates a method for user equipment to interpret the counter-DAI and total-DAI generated according to a first embodiment of the present invention.

[0244] [Table 9]

[0245]

[0246] Referring to Table 9, the Counter-DAI field and Total-DAI field of the PDCCH for scheduling TB-based PDSCH indicate the Counter-DAI and Total-DAI used for TB-based transmissions, respectively. Additionally, the Counter-DAI field and Total-DAI field of the PDCCH for scheduling CBG-based PDSCH indicate the Counter-DAI and Total-DAI used for CBG-based transmissions, respectively.

[0247] First, the counter -DAI for TB-based transmissions can indicate the cumulative number of TB-based PDSCHs scheduled from the first component carrier (i.e., CC#0) to the previous component carrier. In this case, if the value of counter -DAI is C, then the cumulative number of TB-based PDSCHs scheduled to the previous component carrier can be C. Similarly, the counter -DAI for TB-based transmissions can indicate the cumulative number of TB-based PDSCHs scheduled from the first component carrier (i.e., CC#0) to the current component carrier. In this case, if the value of counter -DAI is C, then the cumulative number of TB-based PDSCHs scheduled to the current component carrier can be C+1. Additionally, the total -DAI for TB-based transmissions can indicate the total number of TB-based PDSCHs scheduled for the entire component carrier. If the value of total -DAI is T, then the total number of TB-based PDSCHs scheduled for the entire component carrier can be T+1.

[0248] Next, the counter -DAI used for CBG-based transmissions can indicate the cumulative number of CBG-based PDSCHs scheduled from the first component carrier (i.e., CC#0) to the previous component carrier. In this case, if the value of counter -DAI is C, then the cumulative number of CBG-based PDSCHs scheduled to the previous component carrier can be C. Similarly, the counter -DAI used for CBG-based transmissions can indicate the cumulative number of CBG-based PDSCHs scheduled from the first component carrier (i.e., CC#0) to the current component carrier. In this case, if the value of counter -DAI is C, then the cumulative number of CBG-based PDSCHs scheduled to the current component carrier can be C+1. Additionally, the total -DAI used for CBG-based transmissions can indicate the total number of CBG-based PDSCHs scheduled for the entire component carrier. If the value of total -DAI is T, then the total number of CBG-based PDSCHs scheduled for the entire component carrier can be T+1.

[0249] Figure 21 The diagram illustrates the DAI signaling method according to the first embodiment described above. (See reference...) Figure 21PDSCH can be transmitted to the user equipment via component carriers #0, #1, #3, #4, #5, and #7. Within the component carriers, CBG-based PDSCH is transmitted via component carriers #0, #3, #5, and #7, and TB-based PDSCH is transmitted via component carriers #1 and #4. Since the total number of CBG-based PDSCH scheduled for the entire component carrier is 4, the total-DAI field value for CBG-based transmissions can be set to 3. Additionally, the counter-DAI field value for CBG-based transmissions can be set to an incrementing value starting from 0 based on the cumulative number of CBG-based PDSCH scheduled to the current component carrier. Therefore, the (counter-DAI, total-DAI) fields for the PDCCHs transmitted via component carriers #0, #3, #5, and #7 (CBG-based PDSCH) are (0, 3), (1, 3), (2, 3), and (3, 3), respectively. Similarly, since the total number of TB-based PDSCHs scheduled for the entire component carrier is 2, the value of the total-DAI field for TB-based transmissions can be set to 1. Additionally, the value of the counter-DAI for TB-based transmissions can be set to a value starting from 0, based on the cumulative number of TB-based PDSCHs scheduled to the current component carrier. Therefore, the values ​​of the (counter-DAI, total-DAI) fields for the PDCCHs of component carriers #1 and #4, which transmit TB-based PDSCHs, can be (0, 1) and (1, 1), respectively.

[0250] User equipment (UE) can identify the transmission scheme of a PDSCH by receiving the PDCCH that schedules the PDSCH. For example, UE can identify the transmission scheme of a PDSCH based on the DCI format of the DCI received in the PDCCH. In this case, UE interprets the values ​​of the counter-DAI field and the total-DAI field of the received PDCCH as the counter-DAI and total-DAI for the transmission scheme of the PDSCH scheduled by the PDCCH, respectively. For example, in Figure 21 In the embodiment, when a PDCCH is received that schedules the transmission of PDSCH via component carrier #3, the user equipment can identify that the PDSCH is transmitted via carrier #3 based on CBG, and can interpret the values ​​of the counter-DAI field and the total-DAI field of the PDCCH as the counter-DAI and total-DAI used for CBG-based transmission, respectively. Because the received value of the (counter-DAI, total-DAI) field is (1, 3), the user equipment can identify that a total of 4 CBG-based PDSCHs are allocated to the entire component carrier and that the PDSCH transmitted via component carrier #3 is the second CBG-based PDSCH.

[0251] If the counter-DAI value for CBG-based transmissions does not increase sequentially with the increase of the component carrier index (i.e., not in the order of 0->1->2->3…), the user equipment can determine that the reception of some PDCCHs used to schedule CBG-based transmissions has failed. Furthermore, if the counter-DAI value and the total-DAI value of the last successfully received PDCCH among those scheduled for CBG-based transmissions are not equal, the user equipment can determine that the reception of at least one PDCCH scheduled for CBG-based transmissions after the last PDCCH has failed. In this case, the number of PDCCHs scheduled for CBG-based transmissions that failed to be received after the last successfully received PDCCH can be identified by the difference between the total-DAI value and the counter-DAI value of the last PDCCH. This method of interpreting the counter-DAI value and the total-DAI value can be equally applied to the interpretation of the counter-DAI value and the total-DAI value for TB-based transmissions.

[0252] refer to Figure 21 The user equipment (UE) may fail to decode the PDCCH transmitted via component carriers #3 and #7, which are used to schedule CBG-based transmissions, but may successfully decode the PDCCH transmitted via the remaining component carriers #0 and #5, which are used to schedule CBG-based transmissions. In this case, the UE may receive 0 and 2 as the counter-DAI values ​​for the CBG-based transmissions, respectively. Therefore, the UE can identify that the reception of the PDCCH corresponding to counter-DAI = 1 has failed within the PDCCHs scheduled for CBG-based transmissions. Furthermore, since 3 is received as the total -DAI value for the CBG-based transmissions, but the counter-DAI value of the last successfully received PDCCH in the CBG-based transmissions is 2, the difference between the total -DAI value and the counter-DAI of the last PDCCH is 1. Therefore, the UE can identify that the reception of a PDCCH scheduled for CBG-based transmissions has failed after the last PDCCH.

[0253] Figure 22The illustration illustrates a method for generating a HARQ-ACK bit sequence based on the DAI transmitted using signals according to the first embodiment described above. According to an embodiment of the invention, the user equipment generates a HARQ-ACK bit sequence for the entire component carrier in response to receiving the PDSCH for each component carrier. In this case, the user equipment can generate the HARQ-ACK bit sequence based on the identified transmission scheme for each component carrier. As described above, the HARQ-ACK bit sequence includes a TB-based HARQ-ACK bit sequence and a CBG-based HARQ-ACK bit sequence. Alternatively, the user equipment can generate the HARQ-ACK bit sequence by referring to the DAI of the PDCCH that schedules the PDSCH for each component carrier. In this case, the DAI is applied to both the TB-based HARQ-ACK bit sequence and the CBG-based HARQ-ACK bit sequence.

[0254] More specifically, the user equipment can generate a CBG-based HARQ-ACK bit sequence by combining N bits of HARQ-ACK for each CBG-based transmission in the order of the counter-DAI values ​​of the CBG-based transmission. Each bit in the CBG-based HARQ-ACK bit sequence indicates whether a CBG was successfully received. According to an embodiment of the invention, in the CBG-based HARQ-ACK bit sequence, N HARQ-ACK bits are generated for each TB, where N is the maximum number of CBGs configured for each TB for the user equipment. Alternatively, the user equipment can generate a TB-based HARQ-ACK bit sequence by combining 1 or 2 bits of HARQ-ACK for each TB-based transmission in the order of the counter-DAI values ​​of the TB-based transmission. For reference, the HARQ-ACK for a TB-based transmission can consist of 1 bit per PDSCH when spatial bundling is applied, and can consist of at most 2 bits per PDSCH when spatial bundling is not applied. Figure 22 In the embodiments, it is assumed that for each TB-based transmission, 1 bit of HARQ-ACK is sent as HARQ-ACK.

[0255] According to another embodiment of the present invention, when the user equipment does not receive any PDCCH scheduling CBG-based transmissions, the CBG-based HARQ-ACK bit sequence can be excluded from the HARQ-ACK bit sequence. That is, the HARQ-ACK bit sequence can consist only of the TB-based HARQ-ACK bit sequence. Similarly, when the user equipment does not receive any PDCCH scheduling TB-based transmissions, the TB-based HARQ-ACK bit sequence can be excluded from the HARQ-ACK bit sequence. That is, the HARQ-ACK bit sequence can consist only of the CBG-based HARQ-ACK bit sequence. The user equipment can configure the entire HARQ-ACK bit sequence by combining the CBG-based HARQ-ACK bit sequence and the TB-based HARQ-ACK bit sequence. According to an embodiment of the present invention, the user equipment can configure the entire HARQ-ACK bit sequence by appending the CBG-based HARQ-ACK bit sequence to the TB-based HARQ-ACK bit sequence. (See reference...) Figure 22 The HARQ-ACK bit sequence configured by the user equipment is [x0] (0) ,x1 (0) ,...,x N-1 (0) ,x0 (1) ,x1 (1) ,...,x N-1 (1) ,x0 (2) ,x1 (2) ,...,x N-1 (2) ,x0 (3) ,x1 (3) ,...,x N-1 (3) ,y0 (0) ,y0 (1) Here, x is the HARQ-ACK bit based on CBG, and y is the HARQ-ACK bit based on TB. Additionally, the superscript indicates the counter DAI value of the PDCCH that schedules the PDSCH consisting of the corresponding CBG or TB, and the subscript indicates the ascending order of the corresponding CBG or TB in the PDSCH.

[0256] Meanwhile, according to the first embodiment described above, in order for the user equipment to configure the entire HARQ-ACK bit sequence, the user equipment should receive at least one DAI for TB-based transmissions and at least one DAI for CBG-based transmissions. That is, the user equipment should receive at least one PDCCH scheduling CBG-based transmissions and at least one PDCCH scheduling TB-based transmissions. If the user equipment only receives PDCCHs for one transmission method, it cannot identify scheduling information for the other transmission method. For example, if the user equipment does not successfully receive any PDCCHs scheduling TB-based transmissions, the user equipment does not know whether PDCCHs for TB-based transmissions have been sent, and therefore will not generate a TB-based HARQ-ACK bit sequence. In this case, errors may occur in the interpretation of the HARQ-ACK bit sequence between the base station and the user equipment, thus requiring a method to solve this problem.

[0257] Figure 23 The illustration shows a DAI signaling method according to a second embodiment of the present invention. According to the second embodiment, the base station can transmit the counter-DAI value by scheduling the counter-DAI field of the corresponding PDSCH according to the PDSCH transmission scheme, and can transmit either a total-DAI value for TB-based transmission or a total-DAI value for CBG-based transmission based on the counter-DAI value via the total-DAI field of the PDCCH. That is, according to the second embodiment, the counter-DAI field transmits the counter-DAI value using a signal according to the corresponding PDSCH transmission scheme, but the total-DAI field can selectively transmit either a total-DAI value according to the corresponding transmission scheme or a total-DAI value according to another transmission scheme based on the value of the counter-DAI field. According to the embodiment, when the counter-DAI value is even, the total-DAI field can indicate the total-DAI value according to the corresponding PDSCH transmission scheme, and when the counter-DAI value is odd, the total-DAI field can indicate the total-DAI value according to a transmission scheme other than the corresponding PDSCH transmission scheme.

[0258] User equipment (UE) receives DCI via PDCCH sent by base station and receives DAI in DCI format. UE can generate HARQ-ACK bit sequences by referring to the received DAI. In this case, UE can interpret the counter-DAI received via PDCCH as a counter-DAI for the transmission scheme of PDSCH scheduled by PDCCH. Alternatively, UE can identify whether the total-DAI received via PDCCH is for TB-based transmission or for TB-based transmission based on the value of the counter-DAI. Table 10 illustrates the method by which UE interprets the counter-DAI and total-DAI generated according to the second embodiment of the present invention.

[0259] [Table 10]

[0260]

[0261] Referring to Table 10, the counter-DAI field of the PDCCH for scheduling TB-based PDSCH indicates the counter-DAI for TB-based transmissions, while the counter-DAI field of the PDCCH for scheduling CBG-based PDSCH indicates the counter-DAI for CBG-based transmissions. On the other hand, when the value of the PDCCH counter-DAI field is even, the total-DAI field of the PDCCH for scheduling TB-based PDSCH indicates the total-DAI for TB-based transmissions, and when the value of the PDCCH counter-DAI field is odd, the total-DAI field of the PDCCH for scheduling TB-based PDSCH indicates the total-DAI for CBG-based transmissions. Similarly, when the value of the counter-DAI field of the PDCCH is even, the total-DAI field of the PDCCH for scheduling CBG-based PDSCH indicates the total-DAI used for CBG-based transmissions, and when the value of the counter-DAI field of the PDCCH is odd, the total-DAI field of the PDCCH for scheduling CBG-based PDSCH indicates the total-DAI used for TB-based transmissions. On the other hand, the information indicated by the counter-DAI and total-DAI used for TB-based transmissions and the counter-DAI and total-DAI used for CBG-based transmissions is the same as in the first embodiment described above.

[0262] Figure 23 The diagram illustrates the DAI signaling method according to the second embodiment described above. Figure 23In the embodiment described above, the transmission of CBG-based PDSCH and TB-based PDSCH via each component carrier is the same as in the first embodiment. In this case, the total number of CBG-based PDSCHs scheduled for the entire component carrier is 4, and the total number of CBG-based PDSCHs scheduled for the entire component carrier is 2. According to the second embodiment, in the DAI used for CBG-based transmission, the total-DAI field is set to 3 when the counter-DAI value is even, and the total-DAI field is set to 1 when the counter-DAI value is odd. Therefore, the values ​​of the (counter-DAI, total-DAI) fields of the PDCCHs of component carriers #0, #3, #5, and #7 used to transmit CBG-based PDSCHs are (0, 3), (1, 1), (2, 3), and (3, 1), respectively. Similarly, in the DAI used for TB-based transmission, the total-DAI field is set to 1 when the counter-DAI value is even, and the total-DAI field is set to 3 when the counter-DAI value is odd. Therefore, the values ​​of the (counter-DAI, total-DAI) field used to transmit the TB-based PDSCH component carriers #1 and #4 of the PDCCH can be (0, 1) and (1, 3), respectively.

[0263] User Equipment (UE) can identify the transmission scheme of a PDSCH by receiving the PDCCH that schedules the PDSCH. In this case, the UE interprets the value of the counter-DAI field of the received PDCCH as the counter-DAI for the transmission scheme of the PDSCH scheduled by the PDCCH. On the other hand, when interpreting the value of the total-DAI field of the received PDCCH, if the counter-DAI value is even, the UE interprets it as the total-DAI according to the corresponding PDSCH transmission scheme, and if the counter-DAI value is odd, the UE interprets it as the total-DAI according to a transmission scheme other than the corresponding PDSCH transmission scheme. For example, in Figure 23 In this embodiment, when a PDCCH is received that schedules the transmission of PDSCH via component carrier #3, the user equipment can identify that a CBG-based PDSCH is being transmitted via carrier #3, and interpret the value of the counter-DAI field of the PDCCH as the counter-DAI used for CBG-based transmission. In this case, because the value of the counter-DAI field is odd, the user equipment can interpret the value of the total-DAI field of the PDCCH as the total-DAI used for TB-based transmission. Because the received (counter-DAI, total-DAI) field value is (1, 1), the user equipment can identify that the PDSCH transmitted via component carrier #3 is the second CBG-based PDSCH, and a total of two TB-based PDSCHs are allocated to the entire component carrier.

[0264] The method for determining, based on the counter-DAI and / or total-DAI, that a user equipment (UE) has failed to receive a PDCCH scheduled for a CBG-based or TB-based transmission is similar to the first embodiment described above. However, to obtain the total-DAI for a specific transmission scheme, the UE should refer to the total-DAI field in the PDCCH when the value of the counter-DAI field is even. Therefore, the total-DAI value of the last PDCCH in the first embodiment described above should be replaced with the total-DAI value of the PDCCH in which the value of the counter-DAI field is even. Simultaneously, to obtain the total-DAI for a specific transmission scheme, the UE can refer to the total-DAI field when the value of the counter-DAI field in the PDCCH scheduling another transmission scheme's PDSCH is odd. The UE can determine whether the reception of at least some PDCCHs has failed by referring to the total-DAI obtained thereby for a specific transmission scheme.

[0265] Furthermore, according to the second embodiment described above, even when only a PDCCH for scheduling a PDSCH of one transmission scheme is received, the user equipment can still determine the number of PDSCHs scheduled by another transmission scheme. Therefore, even if all receptions of the PDCCHs for scheduling a specific transmission scheme fail, errors in the interpretation of the HARQ-ACK bit sequence between the base station and the user equipment can be prevented. For example, even if a PDCCH scheduling a TB-based transmission is sent and the user equipment fails to receive the corresponding PDCCH, the user equipment can still identify the number of TB-based PDSCHs scheduled by scheduling the PDCCHs for CBG-based transmissions. However, even when only one PDCCH is successfully received, errors in the interpretation of the HARQ-ACK bit sequence between the base station and the user equipment can still occur.

[0266] Figure 24The diagram illustrates a DAI signaling method according to a third embodiment of the present invention. According to the third embodiment, the base station can generate an independent counter-DAI for each of TB-based and CBG-based transmissions, and generate a common total-DAI used for both transmission schemes. The base station can transmit the counter-DAI value by scheduling the counter-DAI field of the corresponding PDSCH according to the PDSCH transmission scheme, and can transmit the common total-DAI value through the total-DAI field of all PDCCHs. That is, according to the third embodiment, the counter-DAI field signals the counter-DAI value according to the corresponding PDSCH transmission scheme, but the total-DAI field only signals the total-DAI value for either TB-based or CBG-based transmissions. The user equipment can interpret the counter-DAI received through the PDCCH as the counter-DAI for the transmission scheme of the PDSCH scheduled by the PDCCH. Furthermore, the user equipment can interpret the total-DAI received through the PDCCH as the total-DAI commonly applied to all transmission schemes. Table 11 illustrates the method by which a user equipment interprets the counter-DAI and total-DAI generated according to a third embodiment of the present invention.

[0267] [Table 11]

[0268]

[0269] Referring to Table 11, the information indicated by the counter-DAI field of the PDCCH for scheduling TB-based PDSCH and the counter-DAI field of the PDCCH for scheduling CBG-based PDSCH is the same as in the first and second embodiments described above. However, the total-DAI field of the PDCCH for scheduling TB-based PDSCH and the total-DAI field of the PDCCH for scheduling CBG-based PDSCH represent the common total-DAI. The common total-DAI value can be determined according to various embodiments. If at least one TB-based PDSCH and at least one CBG-based PDSCH are scheduled for the entire component carrier, the common total-DAI value can be represented as the total number of PDSCHs for any transmission scheme scheduled for the entire component carrier. According to an embodiment, the common total-DAI value can indicate the total number of CBG-based PDSCHs scheduled for the entire component carrier. According to another embodiment, the common total-DAI value can be determined as a value that minimizes the length of the HARQ-ACK bit sequence. If only PDSCHs for any transmission scheme are scheduled for the entire component carrier, the common total-DAI value can be determined as a predetermined value. According to an embodiment of the present invention, when using 2-bit total -DAI, the predetermined value can be binary "11". Alternatively, when using 3-bit total -DAI, the predetermined value can be "011" or "111".

[0270] Figure 24 The diagram illustrates the DAI signaling method according to the third embodiment described above. Figure 24 In this embodiment, the transmission of CBG-based PDSCH and TB-based PDSCH via each component carrier is the same as in the first embodiment described above. According to this embodiment, when the common total-DAI value represents the total number of CBG-based PDSCHs, both the total-DAI field for CBG-based transmission and the total-DAI field for TB-based transmission are set to 3. Therefore, the values ​​of the (counter-DAI, total-DAI) fields for the PDCCHs of component carriers #0, #3, #5, and #7 used to transmit CBG-based PDSCH are (0, 3), (1, 3), (2, 3), and (3, 3), respectively. Additionally, the values ​​of the (counter-DAI, total-DAI) fields for the PDCCHs of component carriers #1 and #4 used to transmit TB-based PDSCH can be (0, 3) and (1, 3), respectively.

[0271] User Equipment (UE) can identify the PDSCH transmission scheme by receiving the PDCCH that schedules the PDSCH. In this case, the UE interprets the value of the counter-DAI field of the received PDCCH as the counter-DAI used for the transmission scheme of the PDSCH scheduled by the PDCCH. On the other hand, the UE interprets the value of the total-DAI field of the received PDCCH as the total-DAI applied to both CBG-based and TB-based transmissions. For example, in Figure 24 In this embodiment, when a PDCCH is received that schedules a PDSCH to be transmitted via component carrier #3, the user equipment can identify that a CBG-based PDSCH is being transmitted via carrier #3 and interpret the value of the counter-DAI field of the PDCCH as the counter-DAI used for CBG-based transmission. Additionally, the user equipment can interpret the value of the total-DAI field of the PDCCH as the total-DAI applied to both CBG-based and TB-based transmissions. Because the received (counter-DAI, total-DAI) field value is (1, 3), the user equipment can identify that the PDSCH transmitted via component carrier #3 is the second CBG-based PDSCH and allocates a total of four CBG-based and TB-based PDSCHs to the entire component carrier. On the other hand, although the total-DAI field of both CBG-based and TB-based transmissions uses a common total-DAI value, the total number of scheduled CBG-based and TB-based PDSCHs may differ from each other. That is, if the total-DAI field consists of B bits and the common total-DAI value k is signaled, then the total number of scheduled CBG-based PDSCHs can be 2.B *n+k+1, and the total number of TB-based PDSCHs scheduled can be 2. B *m+k+1 (where n and m are non-negative integers). Therefore, if the total -DAI field consists of two bits, the difference between the total number of scheduled CBG-based PDSCHs and the total number of scheduled TB-based PDSCHs can be a multiple of 4.

[0272] The method for determining, based on the counter-DAI and / or total-DAI, that a user equipment (UE) has failed to receive a PDCCH for scheduling a CBG-based or TB-based transmission is similar to the first embodiment described above. However, if the received common-DAI indicates a predetermined value and no PDCCH for scheduling a specific transmission scheme has been received, the UE can determine that the PDSCH for the specific transmission scheme has not been scheduled. When generating a HARQ-ACK bit sequence, the UE may not reuse the HARQ-ACK bit sequence for the specific transmission scheme determined to be unscheduled. For example, if the common-total-DAI indicates a predetermined value and no PDCCH for scheduling a TB-based transmission has been received, the HARQ-ACK bit sequence generated by the UE can be configured by excluding the TB-based HARQ-ACK bit sequence. Similarly, if the common-total-DAI indicates a predetermined value and no PDCCH for scheduling a CBG-based transmission has been received, the HARQ-ACK bit sequence generated by the UE can be configured by excluding the CBG-based HARQ-ACK bit sequence. On the other hand, if the PDCCH for scheduling a specific transmission scheme's PDSCH is not received, but the common total -DAI does not indicate a predetermined value, the user equipment can determine that the PDSCH for the specific transmission scheme has been scheduled, but the user equipment cannot receive the PDSCH. Therefore, when generating the HARQ-ACK bit sequence, the user equipment can reuse the HARQ-ACK bit sequence for the corresponding transmission scheme. According to an embodiment of the present invention, when using 2 bits of total -DAI, the predetermined value can be binary "11". Additionally, when using 3 bits of total -DAI, the predetermined value can be "011" or "111". Furthermore, according to an embodiment of the present invention, the method of not reusing the HARQ-ACK bit sequence for a specific transmission scheme can be applied only when the HARQ-ACK bit sequence is sent via PUSCH. That is, when the common total -DAI indicates a predetermined value and the PDCCH for scheduling a specific transmission scheme's PDSCH is not received, and the HARQ-ACK bit sequence is sent via PUSCH, the user equipment can choose not to reuse the HARQ-ACK bit sequence for the specific transmission scheme.

[0273] Furthermore, according to the third embodiment of the present invention, because a common total DAI is used, mismatches may occur in the total DAI of a specific transmission scheme. Therefore, in the case of a specific transmission scheme, different from the total number of PDSCHs scheduled for that specific transmission scheme, the user equipment can generate a HARQ-ACK bit sequence based on the total number information according to the common total DAI value. For example, if the decoding of PDCCHs transmitted through component carriers #1 and #4, in which TB-based transmissions are scheduled, is successful, the user equipment can receive values ​​0 and 1 as counter-DAIs for TB-based transmissions, respectively. Simultaneously, the user equipment receives value 3 as the total DAI for TB-based transmissions. Because 3 is received as the total DAI value for TB-based transmissions, but the counter-DAI value of the last successfully received PDCCH in the TB-based transmission scheduling is 1, the difference between the total DAI value and the counter-DAI value of the last PDCCH is 2. Therefore, the user equipment can identify that the reception of the two PDCCHs scheduled for TB-based transmissions has failed after the last PDCCH. On the other hand, because the base station knows the actual total number of scheduled TB-based PDSCHs that differs from the common total -DAI value, the base station may ignore the sent NACK due to the mismatch.

[0274] Figure 25 and Figure 26 The illustration is based on an embodiment that generates a HARQ-ACK bit sequence using DAI transmitted by a signal according to the third embodiment described above. Figure 25 The diagram illustrates an embodiment where the common total-DAI value represents the total number of PDSCHs based on CBG, and... Figure 26 The illustration shows an embodiment where the common total-DAI value represents the total number of PDSCHs based on TB. The method for generating the HARQ-ACK bit sequence using the signaled DAI based on the third embodiment of the present invention is similar to the reference... Figure 22 The first embodiment described. However, if the common total-DAI indicates a predetermined value and no PDCCH for scheduling a specific transmission scheme is received, the user equipment may not reuse the HARQ-ACK bit sequence for the specific transmission scheme when generating the HARQ-ACK bit sequence.

[0275] First, refer to Figure 25 The common total-DAI value indicates the total number of CBG-based PDSCHs, and the total-DAI field value is 3. If the total-DAI field consists of 2 bits, it can be interpreted as the total number of CBG-based PDSCHs for the entire component carrier scheduling being 2. 2 *n+3+1=4*(n+1), and the total number of TB-based PDSCHs for the entire component carrier scheduling is 2. 2*m+3+1=4(m+1) (where n and m are non-negative integers). The user equipment can generate CBG-based HARQ-ACK bit sequences and TB-based HARQ-ACK bit sequences respectively, and combine the two HARQ-ACK bit sequences to configure the entire HARQ-ACK bit sequence. According to... Figure 25 In this embodiment, because the total -DAI field value is 3, the TB-based HARQ-ACK bit sequence can include HARQ-ACK[y0] for virtual TB-based PDSCHs (i.e., PDSCH TB-tx#2, #3) in addition to the two TB-based PDSCHs (i.e., PDSCH TB-tx#0, #1). (2) ,y0 (3) Here, virtual PDSCH refers to a PDSCH that does not actually perform transmission. User equipment can configure the entire HARQ-ACK bit sequence by appending a CBG-based HARQ-ACK bit sequence after a TB-based HARQ-ACK bit sequence. (See reference...) Figure 25 The HARQ-ACK bit sequence configured by the user equipment is [x0] (0) ,x1 (0) ,...,x N-1 (0) ,x0 (1) ,x1 (1) ,...,x N-1 (1) ,x0 (2) ,x1 (2) ,...,x N-1 (2) ,x0 (3) ,x1 (3) ,...,x N-1 (3) ,y0 (0) ,y0 (1) ,y0 (2) ,y0 (3) Here, the last two bits of the TB-based HARQ-ACK bit sequence [y0] (2) ,y0 (3) ] is a pseudo-bit containing useless information used to prevent errors in the interpretation of the HARQ-ACK bit sequence between the base station and user equipment.

[0276] Next, refer to Figure 26 The common total-DAI value indicates the total number of PDSCHs based on TB, and the total-DAI field value is 1. If the total-DAI field consists of 2 bits, it can be interpreted as the total number of CBG-based PDSCHs for the entire component carrier scheduling being 2. 2*n+1+1=4*n+2, and the total number of TB-based PDSCHs for the entire component carrier scheduling is 2. 2 *m+1+1=4m+2 (where n and m are non-negative integers). The user equipment can generate CBG-based HARQ-ACK bit sequences and TB-based HARQ-ACK bit sequences respectively, and combine the two HARQ-ACK bit sequences to configure the entire HARQ-ACK bit sequence. According to Figure 26 In this embodiment, since the total -DAI field value is 1, the TB-based HARQ-ACK bit sequence can include a virtual CBG-based PDSCH (i.e., PDSCH CBG-tx#4,#5) HARQ-ACK in addition to the four CBG-based PDSCHs (i.e., PDSCH CBG-tx#0,#1,#2,#3). (4) ,x1 (4) ,...,x N-1 (4) ,x0 (5) ,x1 (5) ,...,x N-1 (5) User equipment can configure the entire HARQ-ACK bit sequence by appending a CBG-based HARQ-ACK bit sequence after a TB-based HARQ-ACK bit sequence. (Reference) Figure 26 The HARQ-ACK bit sequence configured by the user equipment is [x0] (0) ,x1 (0) ,...,x N-1 (0) ,x0 (1) ,x1 (1) ,...,x N-1 (1) ,x0 (2) ,x1 (2) ,...,x N-1 (2) ,x0 (3) ,x1 (3) ,...,x N-1 (3) ,x0 (4) ,x1 (4) ,...,x N-1 (4) ,x0 (5) ,x1 (5) ,...,x N-1 (5) ,y0 (0) ,y0 (1) Here, the last 2N bits of the CBG-based HARQ-ACK bit sequence [x0] (4),x1 (4) ,...,x N-1 (4) ,x0 (5) ,x1 (5) ,...,x N-1 (5) ] is a pseudo-bit containing useless information used to prevent errors in the interpretation of the HARQ-ACK bit sequence between the base station and user equipment.

[0277] Figure 27 The illustration shows another embodiment based on the signal-transmitted DAI generating HARQ-ACK bit sequence according to the third embodiment described above. As described above, according to another embodiment of the invention, the PDSCH can be scheduled only for either CBG-based or TB-based transmissions. In this case, in order to signal-transmit the PDSCH for only any one of the transmission schemes, the total -DAI value can be set to a predetermined value of 3 (i.e., binary "11"). Furthermore, in Figure 27 In the embodiment, it is assumed that TB-based PDSCH is transmitted via component carriers #1 and #4, and CBG-based PDSCH is not scheduled.

[0278] first, Figure 27 (a) illustrates an embodiment where the value of the total-DAI field indicates the total number of TB-based PDSCHs. Since the number of TB-based PDSCHs scheduled for the entire component carrier is 2, the value of the total-DAI field is set to 1. In this case, the total number of CBG-based PDSCHs scheduled for the entire component carrier can be interpreted as 2. Therefore, the user equipment can generate a 2*N bit HARQ-ACK[x0] for two virtual CBG-based PDSCHs. (0) ,x1 (0) ,...,x N-1 (0) ,x0 (1) ,x1 (1) ,...,x N-1 (1) Since user equipment can only detect PDCCH based on TB-based PDSCH, the 2*N bit HARQ-ACK can be set as all NACKs as pseudo bits.

[0279] Next, Figure 27(b) illustrates an embodiment where the value of the total-DAI field indicates a predetermined value representing a PDSCH that is not scheduled for a particular transmission scheme. Here, the predetermined value is 3 (i.e., binary "11"). Because the received total-DAI indicates the predetermined value and no PDCCH for scheduling CBG-based PDSCHs is received, the user equipment can determine that CBG-based PDSCHs are not scheduled. Therefore, in addition to the CBG-based HARQ-ACK bit sequence, the user equipment can generate the entire HAQR-ACK bit sequence, which only includes the TB-based HARQ-ACK bit sequence. In this case, because the value of the total-DAI field is 3, the user equipment can interpret this as the total number of TB-based PDSCHs scheduled for the entire component carrier being 4. However, since the user equipment can actually receive two TB-based PDSCHs, it can generate 2-bit HARQ-ACK[y0] for two virtual TB-based PDSCHs. (2) ,y0 (3) Because user equipment cannot receive PDCCH based on scheduled virtual TB-based PDSCH, the 2-bit HARQ-ACK can be set as a pseudo-bit for all NACKs.

[0280] Meanwhile, in the above embodiments, it is assumed that one HARQ-ACK bit is generated for each TB in the TB-based HARQ-ACK bit sequence, and N HARQ-ACK bits are generated for each TB in the CBG-based HARQ-ACK bit sequence. In the following embodiments, it can be assumed that any one of 1 to N HARQ-ACK bits is generated for each TB in the CBG-based HARQ-ACK bit sequence. For example, the length of the HARQ-ACK bits of the CBG-based PDSCH can be determined based on the number of CBGs actually scheduled and transmitted in the PDSCH. In addition, in the following embodiments, it can be assumed that a TB-based transmission consists of one CBG-based transmission. That is, each embodiment can be described by assuming that a PDSCH consisting of one TB is a PDSCH consisting of one CBG, and a PDSCH consisting of two TBs is a PDSCH consisting of two CBGs. Therefore, separate expressions for TB-based transmissions or CBG-based transmissions can be omitted. For reference, the user equipment can identify whether to apply TB-based transmissions or CBG-based transmissions to the PDSCH scheduled by the PDCCH through the information of the PDCCH.

[0281] Figure 28The illustration shows a DAI signaling method according to a fourth embodiment of the present invention. According to the fourth embodiment, the base station can generate a counter-DAI value and a total-DAI value based on the number of scheduled CBGs, and transmit them through the counter-DAI field and the total-DAI field. That is, the counter-DAI represents the cumulative number of CBGs scheduled from the first component carrier (i.e., component carrier #0) to the previous component carrier. Additionally, the total-DAI represents the total number of CBGs scheduled across the entire component carrier. (See reference...) Figure 28 PDSCH can be transmitted to the user equipment via component carriers #0, #1, #3, #4, #5, and #7. In this case, the number of CBGs transmitted via component carriers #0, #1, #3, #4, #5, and #7 can be 2, 3, 1, 4, 3, and 3, respectively. Since the total number of CBGs scheduled for the entire component carrier is 16, the values ​​of the (counter-DAI, total-DAI) field for each PDSCH on component carriers #0, #1, #3, #4, #5, and #7 can be (0, 16), (2, 16), (5, 16), (6, 16), (10, 16), and (13, 16), respectively.

[0282] When a user equipment receives a PDCCH, it can identify the number of CBGs included in the PDSCH scheduled by the PDCCH using the CBG scheduling information included in the PDCCH. Additionally, the user equipment can identify the total number of CBGs scheduled for the entire component carrier using the total -DAI value, and the transmission order of the CBGs included in the PDSCH scheduled by the corresponding PDCCH using the counter -DAI value. If the PDSCH scheduled by the current PDCCH contains k CBGs and the value of the (counter -DAI, total -DAI) field is (C, T), then the PDSCH scheduled for the entire component carrier includes a total of T CBGs, and the CBGs included in the PDSCH scheduled by the current PDCCH are the (C+1)th to (C+k)th CBGs out of the total T CBGs. For example, when the user equipment successfully receives a PDCCH scheduled to be transmitted via component carrier #3, the user equipment can identify that the PDSCH transmitted via component carrier #3 includes 1 CBG based on the CBG scheduling information included in the PDCCH. Additionally, the user equipment can identify the total number of CBGs in the entire component carrier schedule as 16 by the received values ​​(5, 16) of the (counter-DAI, total-DAI) field, and the CBG included in the PDSCH transmitted via component carrier #3 is the sixth CBG out of the total 16 CBGs.

[0283] User equipment can generate the HARQ-ACK bit sequence as follows. First, the length of the HARQ-ACK bit sequence can be determined based on the total -DAI value. If the total -DAI field consists of B bits and the value of the total -DAI field is T, then the length of the HARQ-ACK bit sequence can be 2. B *n+T. Here, n is a non-negative integer and can be the minimum value allowed to include the HARQ-ACK bits of CBGs included in the PDSCH scheduled by the successfully received PDCCH in the HARQ-ACK bit sequence. The user equipment can determine the position of the HARQ-ACK bits of the CBGs scheduled by the corresponding PDCCH based on the counter-DAI value obtained from the successfully received PDCCH and the number of scheduled CBGs k. That is, when the value of the counter-DAI field is C, the position of the HARQ-ACK bits in the HARQ-ACK bit sequence can be from C+1 to C+k. If the counter-DAI field consists of A bits and the value of the counter-DAI field is C, then the position of the available HARQ-ACK bits starts from the 2nd bit. A *m+C+1 to the 2nd A *m+C+k. Here, m is a non-negative integer. Also, unmapped HARQ-ACK bits in the HARQ-ACK bit sequence can be set to NACK.

[0284] Meanwhile, according to the fourth embodiment described above, when the user equipment successfully receives the PDCCH, the total number of CBGs scheduled for the entire component carrier and the transmission order of the CBGs included in the PDSCH scheduled by the corresponding PDCCH can be identified. However, since various numbers of CBGs can be transmitted through a single PDSCH, when the user equipment identifies the failure to receive multiple CBGs, it cannot identify the number of PDSCHs that were not received.

[0285] Figure 29 The illustration shows a DAI signaling method according to a fifth embodiment of the present invention. According to the fifth embodiment, the base station generates a first counter-DAI (i.e., counter-DAI#1) value and a first total-DAI (i.e., total-DAI#1) value based on the number of scheduled PDSCHs, and generates a second counter-DAI (i.e., counter-DAI#2) value and a second total-DAI (i.e., total-DAI#2) value based on the number of CBGs. The base station can transmit the generated DAI values ​​through the first counter-DAI field, the first total-DAI field, the second counter-DAI field, and the second total-DAI field, respectively.

[0286] First, the first counter -DAI represents the cumulative number of PDSCHs scheduled from the first component carrier (i.e., component carrier #0) to the previous component carrier. In this case, if the value of the first counter -DAI is C, then the cumulative number of PDSCHs scheduled to the previous component carrier can be C (i.e., the cumulative number of PDSCHs scheduled to the current component carrier is C+1). Additionally, the first total -DAI represents the total number of PDSCHs scheduled for the entire component carrier. If the value of the first total -DAI is T, then the total number of PDSCHs scheduled for the entire component carrier can be T+1.

[0287] Next, the second counter-DAI is determined based on the cumulative number of CBGs scheduled from the first component carrier (i.e., component carrier #0) to the previous component carrier. Additionally, the second total-DAI is determined based on the total number of CBGs scheduled for all component carriers. According to an embodiment of the invention, to reduce signaling overhead, the values ​​of the second counter-DAI field and the second total-DAI field can be set by subtracting the values ​​of the first counter-DAI field and the first total-DAI field from the information to be transmitted using the signal, respectively. For example, if the number of CBGs scheduled to the previous component carrier is P, and the first counter-DAI value of the current component carrier is C1, then the second counter-DAI value C2 of the current component carrier can be set to C2 = P - C1. Furthermore, if the total number of CBGs scheduled for the entire component carrier is Q and the first total-DAI value is T1, then the second total-DAI value T2 can be set to T2 = Q - T1.

[0288] exist Figure 29 In this embodiment, the transmission of CBG via each component carrier is the same as in the fourth embodiment described above. In this case, the values ​​of the (first counter-DAI, first total-DAI, second counter-DAI, second total-DAI) field for each PDCCH of component carriers #0, #1, #3, #4, #5, and #7 are (0, 5, 0, 11), (1, 5, 1, 11), (2, 5, 3, 11), (3, 5, 3, 11), (4, 5, 6, 11), and (5, 5, 8, 11).

[0289] When a user equipment receives a PDCCH, it can identify the number of CBGs included in the PDSCH scheduled by the PDCCH using the CBG scheduling information included in the PDCCH. Additionally, the user equipment can identify the total number of PDSCHs scheduled for the entire component carrier using the first total -DAI value, and the transmission order of the PDSCHs scheduled by the corresponding PDCCH using the first counter -DAI value. Furthermore, the user equipment can identify the total number of CBGs scheduled for the entire component carrier using the second total -DAI value, and the transmission order of the CBGs included in the PDSCHs scheduled by the corresponding PDCCH using the second counter -DAI value. If the PDSCH scheduled by the current PDCCH includes k CBGs, and the values ​​of the (first counter -DAI, first total -DAI, second counter -DAI, second total -DAI) field are (C1, T1, C2, T2), then the total number of PDSCHs scheduled for the entire component carrier is T1+1, and the total number of CBGs scheduled for the entire component carrier is T1+T2. In addition, among a total of T1+T2 CBGs, the order of PDSCHs scheduled by the current PDCCH is the C1th, and the CBGs included in the PDSCH are the C1+C2+1th to the C1+C2+kth CBGs.

[0290] If the first counter -DAI value does not increase sequentially with the component carrier index (i.e., not in the order of 0->1->2->3…), the user equipment determines that the reception of some PDCCHs has failed. Furthermore, if the first counter -DAI value and the first total -DAI value of the last successfully received PDCCH are not equal, the user equipment can determine that the reception of at least one PDCCH has failed after the last PDCCH. In this case, the number of PDCCHs that failed to be received after the last successfully received PDCCH can be identified by the difference between the first total -DAI value and the first counter -DAI value of the last PDCCH.

[0291] User equipment (UE) can generate the HARQ-ACK bit sequence as follows: First, the length of the HARQ-ACK bit sequence can be determined based on the sum of the first total-DAI value and the second total-DAI value. The UE can determine the positions of the HARQ-ACK bits for the CBGs scheduled by the corresponding PDCCH based on the first counter-DAI value and the second counter-DAI value obtained from the successfully received PDCCH, and the number of scheduled CBGs, k. That is, when the value of the (first counter-DAI, first total-DAI, second counter-DAI, second total-DAI) field is (C1, T1, C2, T2), the positions of the HARQ-ACK bits in the HARQ-ACK bit sequence can be from C1+C2+1 to C1+C2+k. Simultaneously, bits in the HARQ-ACK bit sequence that are not mapped to HARQ-ACK bits can be set to NACK.

[0292] Meanwhile, according to the fifth embodiment described above, when the user equipment successfully receives the PDCCH, it can identify the total number of CBGs scheduled for the entire component carrier and the transmission order of the CBGs included in the PDSCHs scheduled by the corresponding PDCCH. Furthermore, when the user equipment fails to receive at least one PDSCH, it can identify which PDSCH failed to be received. However, according to this embodiment, there may be a drawback of high DCI overhead.

[0293] Figure 30 The illustration shows a DAI signaling method according to a sixth embodiment of the present invention. According to the sixth embodiment, the base station generates a first counter-DAI (i.e., counter-DAI#1) value and a first total-DAI (i.e., total-DAI#1) value based on the number of scheduled PDSCHs, and generates a second counter-DAI (i.e., counter-DAI#2) value based on the number of CBGs. The base station can transmit the generated DAI values ​​through the first counter-DAI field, the first total-DAI field, and the second counter-DAI field, respectively.

[0294] In the sixth embodiment of the present invention, the definitions of the first counter-DAI and the first total-DAI are the same as those in the above fifth embodiment. However, the second counter-DAI is determined based on the number of CBGs scheduled in the K PDSCHs before the current component carrier. According to an embodiment of the present invention, the K PDSCHs before the current component carrier can be determined cyclically. That is, if a total of k PDSCHs (where k < K) are scheduled from the first component carrier (i.e., component carrier #0) to the previous component carrier, the K PDSCHs can include the k PDSCHs from the first component carrier to the previous component carrier and the K - k PDSCHs in reverse order starting from the last component carrier. According to an embodiment, the value of K can be determined based on the value of the first total-DAI (i.e., the total number of CBGs scheduled for the entire component carrier). For example, when the value of the first total-DAI is 1, 2, or 3 respectively, the value of K can be set to 0, 1, or 2. In addition, when the value of the first total-DAI is greater than 3, the value of K can be set to 3. According to an embodiment of the present invention, in order to reduce signaling overhead, the value of the second counter-DAI field can be set by subtracting K from the number of CBGs scheduled in the K PDSCHs before the current component carrier.

[0295] In Figure 30 the embodiment of, the case of transmitting CBGs through each component carrier is the same as that in the above fourth embodiment. In this case, the value of K can be set to 3, and the values of the (first counter-DAI, first total DAI, second counter-DAI) fields are (0, 5, 7), (1, 5, 5), (2, 5, 5), (3, 5, 3), (4, 5, 5), and (5, 5, 5).

[0296] The method for determining that the user equipment failed to receive some PDCCHs is the same as in the fifth embodiment. Additionally, in the sixth embodiment, since the second counter-DAI is determined based on the number of CBGs scheduled in the K PDSCHs preceding the current component carrier, the user equipment can identify the number of CBGs included in the PDSCHs scheduled by the failed-to-receive PDCCHs based on the second counter-DAI. For example, it can be assumed that the user equipment failed to receive a PDCCH where the first counter-DAI value is 2, and successfully received the remaining PDCCHs. Because the value 2 is not present in the first counter-DAI values ​​of the successfully received PDCCHs, the user equipment can identify the reception failure of the PDCCH where the first counter-DAI value is 2. The number of CBGs included in the PDSCHs scheduled by the PDCCH where the first counter-DAI value is 2 can be identified based on the value obtained by subtracting the number of CBGs included in the PDSCHs scheduled by the PDCCHs where the first counter-DAI value is 0 and 1 from the second counter-DAI value of the PDCCH where the first counter-DAI value is 3. Figure 30 In the embodiment, the second counter-DAI value of the PDCCH with a first counter-DAI value of 3 is 3, and the number of CBGs included in the PDSCH scheduled by the PDCCHs with first counter-DAI values ​​of 0 and 1 are 2 and 3, respectively. Therefore, the number x of CBGs included in the PDSCH scheduled by the PDCCH with a first counter-DAI value of 2 satisfies (2+3+x)-K=3. Here, since K is 3, the user equipment can recognize x as 1.

[0297] Figure 31The illustration illustrates an embodiment of generating a HARQ-ACK bit sequence from the DAI transmitted by signal according to the sixth embodiment described above. As in the embodiments above, the user equipment can identify the number of PDSCHs transmitted via component carriers based on the first counter-DAI value and the first total-DAI value. Additionally, the user equipment can identify the number of CBGs transmitted via each component carrier based on the second counter-DAI value. Therefore, the user equipment can sequentially increment the value of the first counter-DAI field from 0 to the first total-DAI value and generate a HARQ-ACK bit sequence by combining the HARQ-ACK bits used for PDSCHs scheduled by the corresponding PDCCH. However, when the value of K is 2 or greater (e.g., when K = 2 or 3), the user equipment can cyclically increment the value of the first counter-DAI field from i and generate a HARQ-ACK bit sequence by combining the HARQ-ACK bits used for PDSCHs scheduled by the corresponding PDCCH. In this case, to indicate the value of i, a header indicating configuration information for the HARQ-ACK bit sequence can be added at the beginning or end of the HARQ-ACK bit sequence. That is, the HARQ-ACK bit sequence can include a header and a main bit sequence. The header indicates information about which PDSCH of the HARQ-ACK bits the main bit sequence begins with.

[0298] refer to Figure 31 When K is 2 or 3, the candidate for the HARQ-ACK bit sequence that can be sent by the user equipment can be 4. Therefore, the header consists of two bits and indicates which PDSCH the main bit sequence begins with for the HARQ-ACK bits. For example, if the header indicates "00", the main bit sequence begins with the HARQ-ACK bit of the first PDSCH. Similarly, if the header indicates "01", "10", or "11", the main bit sequence begins with the HARQ-ACK bit of the second, third, or fourth PDSCH, respectively.

[0299] Meanwhile, according to the sixth embodiment, when the user equipment successfully receives the PDCCH, it can identify the total number of PDSCHs scheduled for the entire component carrier and the transmission order of the PDSCHs scheduled by the corresponding PDCCH. Additionally, the user equipment can identify information about the number of CBGs using the second counter -DAI value. According to the sixth embodiment, because the second total -DAI field is not sent, the overhead of DCI signaling can be reduced compared to the fifth embodiment. However, because the header should be added to the HARQ-ACK bit sequence sent by the user equipment, the overhead of UCI transmission may increase.

[0300] Figure 32The illustration shows a DAI signaling method according to a seventh embodiment of the present invention. According to the seventh embodiment, the base station separates the transmission type into a first type of transmission and a second type of transmission based on the number of CBGs included in the scheduled PDSCH, and independently generates a first counter-DAI (i.e., counter-DAI#1) and a first total-DAI (i.e., total-DAI#1) value, as well as a second counter-DAI (i.e., counter-DAI#2) and a second total-DAI (i.e., total-DAI#2) value based on the number of PDSCHs for each transmission type. The base station can send DAI values ​​of the same type as the transmission type of the PDSCH scheduled by the PDCCH through the first counter-DAI field, the first total-DAI field, the second counter-DAI field, and the second total-DAI field of the PDCCH. When the user equipment receives the PDCCH, the user equipment can identify the number of CBGs included in the PDSCH scheduled by the PDCCH through the CBG scheduling information included in the PDCCH. Additionally, the user equipment can identify the transmission type of the PDSCH based on the number of CBGs included in the PDSCH. The user equipment interprets the values ​​of the first counter-DAI field, the first total-DAI field, the second counter-DAI field, and the second total-DAI field received via PDCCH as DAI values ​​for the identified transmission type.

[0301] According to an embodiment of the present invention, the first type of transmission is the transmission of a PDSCH consisting of a predetermined number or fewer CBGs, and the second type of transmission is the transmission of a PDSCH consisting of more than a predetermined number of CBGs. According to the embodiment, the predetermined number may be... or Here, N can be the maximum number of CBGs configured per TB in the user equipment. It is the largest natural number less than or equal to x, and It is the smallest natural number greater than or equal to x. In the following examples, it is assumed that the predetermined quantity is... However, according to this embodiment, it can be used Or other values ​​can be used instead.

[0302] Based on the first type of transmission, the DAI value used for the first type of transmission is applied to the PDSCH and CBG, and the definition of the DAI value is the same as those in the fifth embodiment described above. Similarly, based on the second type of transmission, the DAI value used for the second type of transmission is applied to the PDSCH and CBG. However, in the DAI used for the second type of transmission, the first counter-DAI and the first total-DAI can be set in the same manner as in the fifth embodiment described above, but the second counter-DAI and the second total-DAI can be set to have a granularity different from that according to the fifth embodiment. That is, because the minimum number of CBGs included in the PDSCH performing the second type of transmission is... Therefore, signaling overhead is reduced by subtracting the value based on the minimum number when setting the second counter-DAI value and the second total-DAI value for the second type of transmission. More specifically, if the number of CBGs scheduled to the previous component carrier for the second type of transmission is P and the first counter-DAI value of the current component carrier is C1, then the second counter-DAI value C2 of the current component carrier can be set to... Furthermore, if the total number of CBGs based on the second type of transmission scheduled for the entire component carrier is Q and the first total -DAI value is T1, then the second total -DAI value T2 can be set to...

[0303] refer to Figure 32 PDSCH can be transmitted to the user equipment via component carriers #0, #1, #3, #4, #5, and #7. In this case, the number of CBGs transmitted via component carriers #0, #1, #3, #4, #5, and #7 can be 2, 3, 1, 4, 3, and 4, respectively. If N=4, then the PDSCH scheduled in component carriers #0 and #3 is based on the first type of transmission, and the PDSCH scheduled in component carriers #1, #4, #5, and #7 is based on the second type of transmission. Therefore, the values ​​of the (first counter - DAI, first total - DAI, second counter - DAI, second total - DAI) fields for each PDCCH on component carriers #0 and #3, where the PDSCH is scheduled based on the first type of transmission, can be (0, 1, 0, 1) and (1, 1, 1, 1), respectively. Furthermore, the values ​​of the (first counter-DAI, first total-DAI, second counter-DAI, second total-DAI) fields for each PDCCH of component carriers #1, #4, #5, and #7, in which PDSCHs based on the second type of transmission are scheduled, can be (0, 3, 0, 2), (1, 3, 0, 2), (2, 3, 1, 2), and (3, 3, 1, 2), respectively. Table 12 illustrates a method for user equipment to interpret the counter-DAI and total-DAI generated according to the seventh embodiment of the present invention.

[0304] [Table 12]

[0305]

[0306] Referring to Table 12, the user equipment can identify the number of PDSCHs of the corresponding transmission type scheduled to the component carrier and the transmission order of the PDSCHs of the transmission type scheduled by the PDCCH through the values ​​of the first counter-DAI field and the first total-DAI field of the PDCCH. Additionally, the user equipment can identify the number of CBGs included in the PDSCH of the corresponding transmission type scheduled to the component carrier and the transmission order of the CBGs included in the PDSCH of the transmission type scheduled by the PDCCH through the values ​​of the second counter-DAI field and the second total-DAI field of the PDCCH. If the PDSCH scheduled by the current PDCCH contains k CBGs and the transmission type is x (where x = 1 or 2), and the values ​​of the (first counter-DAI, first total-DAI, second counter-DAI, second total-DAI) field are (C1, T1, C2, T2), then the total number of PDSCHs transmitted based on type x scheduled for the entire component carrier is T1+1, and the order of the PDSCHs transmitted based on type x scheduled by the current PDCCH is C1+1. Furthermore, the CBG included in the PDSCH based on type x is from the Mth x *C1+C2+1 to the Mth x *C1+C2+k CBGs. Here, when x=1, M x =1, and when x=2 Meanwhile, the method for determining that the user equipment failed to receive certain PDCCHs is the same as in the above embodiments.

[0307] Figure 33The illustration illustrates an embodiment of generating a HARQ-ACK bit sequence based on the DAI signal transmitted according to the seventh embodiment described above. First, the user equipment (UE) can combine HARQ-ACKs for the PDSCH according to the order of the first counter-DAI values ​​based on a first type of transmission to generate a HARQ-ACK sequence based on the first type. Alternatively, the UE can combine HARQ-ACKs for the PDSCH according to the order of the first counter-DAI values ​​based on a second type of transmission to generate a HARQ-ACK sequence based on the second type. In this case, "NACK" can be used as a HARQ-ACK for a PDSCH in which reception of the PDCCH has failed. According to the embodiment, if no PDCCH scheduled for a first type of transmission is received, the HARQ-ACK bit sequence generated by the UE can be configured to exclude HARQ-ACK bit sequences used for first type-based transmissions. Similarly, if no PDCCH scheduled for a second type of transmission is received, the HARQ-ACK bit sequence generated by the UE can be configured to exclude HARQ-ACK bit sequences used for second type-based transmissions. User equipment can configure the entire HARQ-ACK bit sequence by combining the HARQ-ACK bit sequence for transmission based on the first type and the HARQ-ACK bit sequence for transmission based on the second type in a predetermined order. According to an embodiment, user equipment can configure the entire HARQ-ACK bit sequence by appending the HARQ-ACK bit sequence for transmission based on the first type to the HARQ-ACK bit sequence for transmission based on the second type. (Reference) Figure 33 The HARQ-ACK bit sequence configured for the user equipment is [x0 (0) ,x1 (0) x2 (0) ,x0 (1) ,x1 (1) x2 (1) x3 (1) ,x0 (2) ,x1 (2) x2 (2) ,x0 (3) ,x1 (3) x2 (3) x3 (3) ,y0 (0) ,y1 (0) ,y0 (1) However, the present invention is not limited thereto, and the entire HARQ-ACK bit sequence can be configured by combining bit sequences in the reverse order.

[0308] Meanwhile, according to the seventh embodiment, the transmission type can be separated into a first type of transmission and a second type of transmission based on the number of CBGs included in the PDSCH, and the independent DAI value for each transmission type can be signaled to reduce the overhead of DCI. However, there is a drawback that the user equipment must always receive the PDCCH that schedules different transmission types.

[0309] Figure 34 This is a schematic diagram illustrating the DAI signaling method according to an eighth embodiment of the present invention. The eighth embodiment of the present invention can be implemented by combining at least some components of the second and seventh embodiments described above. That is, the base station separates the transmission type into a first type of transmission and a second type of transmission based on the number of CBGs included in the scheduled PDSCH, and generates a first counter-DAI (i.e., counter-DAI#1) and a first total-DAI (i.e., total-DAI#1) value, as well as a second counter-DAI (i.e., counter-DAI#2) and a second total-DAI (i.e., total-DAI#2) value based on the number of PDSCHs for each transmission type. In this case, when the first counter-DAI value is even, the base station can send the first total-DAI value and the second total-DAI value for the same type of transmission as the PDSCH scheduled by the PDCCH through the first total-DAI field and the second total-DAI field, respectively. However, when the first counter-DAI value is odd, the base station can transmit a first total-DAI value and a second total-DAI value for a type different from the transmission type of the PDSCH scheduled by the PDCCH, respectively, through the first total-DAI field and the second total-DAI field. In this case, the definition of the DAI value is the same as in the seventh embodiment described above.

[0310] exist Figure 34In this embodiment, the transmission of CBG via each component carrier is the same as in the seventh embodiment described above. The PDSCH scheduled on component carriers #0 and #3 is a PDSCH based on the first type of transmission, and the PDSCH scheduled on component carriers #1, #4, #5, and #7 is a PDSCH based on the second type of transmission. Therefore, the values ​​of the (first counter-DAI, first total-DAI, second counter-DAI, second total-DAI) fields for each PDCCH on component carriers #0 and #3, where the PDSCH is scheduled based on the first type of transmission, can be (0, 1, 0, 1) and (1, 3, 1, 2), respectively. Furthermore, the values ​​of the (first counter-DAI, first total-DAI, second counter-DAI, second total-DAI) fields for each PDCCH on component carriers #1, #4, #5, and #7, where the PDSCH is scheduled based on the second type of transmission, can be (0, 3, 0, 2), (1, 1, 0, 1), (2, 3, 1, 2), and (3, 1, 1, 1), respectively. Meanwhile, the method for generating a HARQ-ACK bit sequence based on the DAI transmitted by the signal according to the eighth embodiment is the same as described above. Figure 33 The embodiments are the same.

[0311] Meanwhile, according to the eighth embodiment, the transmission type can be separated into a first type of transmission and a second type of transmission based on the number of CBGs included in the PDSCH, and an independent DAI value can be sent for each transmission type to reduce DCI overhead. Furthermore, even when only a PDCCH for scheduling PDSCH based on one transmission type is received, the user equipment can still determine the number of PDSCHs and CBGs based on the other transmission type. However, the user equipment should always receive multiple PDCCHs indicating the total DAI for different types.

[0312] Figure 35This is a schematic diagram illustrating the DAI signaling method according to a ninth embodiment of the present invention. The ninth embodiment of the present invention can be implemented by combining at least some components of the third and seventh embodiments described above. That is, the base station separates the transmission type into a first type of transmission and a second type of transmission based on the number of CBGs included in the scheduled PDSCH, and generates a first counter-DAI (i.e., counter-DAI#1) value based on the number of PDSCHs and a second counter-DAI (i.e., counter-DAI#2) value based on the number of CBGs for each transmission type. Additionally, the base station generates a common first total-DAI (i.e., total-DAI#1) value and a common second total-DAI (i.e., total-DAI#2) value that are used together for both transmission types. The base station transmits the first counter-DAI value and the second counter-DAI value by scheduling the first counter-DAI field and the second counter-DAI field of the corresponding PDSCH's PDCCH according to the transmission type of the PDSCH. Furthermore, the base station can transmit the common first total-DAI value and the common second total-DAI value through the first total-DAI field and the second total-DAI field of all PDCCHs, regardless of the transmission type.

[0313] According to another embodiment, when scheduling any transmission type of PDSCH for the entire component carrier only, the common first total-DAI value can be determined as a predetermined value. According to an embodiment of the invention, when using 2 bits of total-DAI, the predetermined value can be binary "11". Furthermore, when using 3 bits of total-DAI, the predetermined value can be "011" or "111". Meanwhile, the method for determining the first counter-DAI value and the second counter-DAI value is the same as the method in the seventh embodiment described above.

[0314] exist Figure 35 In this embodiment, the transmission of CBG via each component carrier is the same as in the seventh embodiment described above. Furthermore, it can be assumed that the common first total-DAI value and the common second total-DAI value are determined based on the number of PDSCHs and CBGs based on the second type of transmission, respectively. Therefore, the values ​​of the (first counter-DAI, first total-DAI, second counter-DAI, second total-DAI) field for each PDCCH of component carriers #0 and #3, where PDSCHs based on the first type of transmission are scheduled, can be (0, 3, 0, 2) and (1, 3, 1, 2), respectively. Furthermore, the values ​​of the (first counter-DAI, first total-DAI, second counter-DAI, second total-DAI) field for each PDCCH of component carriers #1, #4, #5, and #7, where PDSCHs based on the second type of transmission are scheduled, can be (0, 3, 0, 2), (1, 3, 0, 2), (2, 3, 1, 2), and (3, 3, 1, 2), respectively.

[0315] Figure 36 The illustration shows an embodiment based on the DAI signal transmitted according to the ninth embodiment described above, generating a HARQ-ACK bit sequence. The HAQR-ACK bit sequence can be used in conjunction with the above... Figure 33 The same method is used to generate the virtual HARQ-ACK [z0, z1, z2] for the virtual CBG included in the two virtual PDSCHs, since (3, 2) is used instead of (1, 1) as the value of the (first total - DAI, second total - DAI) field for the PDSCH based on the first type of transmission.

[0316] Figure 37 The illustration shows a DAI signaling method according to a tenth embodiment of the present invention. When a base station is configured with CBG-based transmission, the number of CBGs configured for each TB in each component carrier or cell can be different from each other. For example, the number of CBGs for each TB in component carrier #0 can be configured to be 2, and the number of CBGs for each TB in component carrier #1 can be configured to be 4. Furthermore, when a user equipment is configured with a transmission mode in which two TBs can be transmitted in one PDSCH, the number of CBGs for each TB can be set equally in both TBs.

[0317] A user equipment (UE) configured in a transmission mode capable of transmitting one TB in one PDSCH should send HARQ-ACK bits to the base station based on the number of CBGs configured. If a UE configured in a transmission mode in which two TBs can be transmitted in one PDSCH is configured not to perform spatial bonding, the UE should send HARQ-ACK bits to the base station based on twice the number of CBGs configured for each TB. Conversely, if a UE configured in a transmission mode in which two TBs can be transmitted in one PDSCH is configured to perform spatial bonding, the UE should send HARQ-ACK bits to the base station based on the number of CBGs configured for each TB. In the following embodiments of the invention, it is assumed that the UE is configured to perform spatial bonding or is configured in a transmission mode capable of transmitting one TB in one PDSCH. Specific embodiments of the HARQ-ACK bonding method including spatial bonding will be described later. However, embodiments of the invention can be extended to UEs configured in a transmission mode where two TBs can be transmitted in one PDSCH and are configured not to perform spatial bonding.

[0318] According to an embodiment of the invention, the DCI of the PDCCH that schedules the PDSCH may include a counter-DAI and a total-DAI. In this case, the counter-DAI represents the cumulative number of CBG groups scheduled from the first component carrier (i.e., component carrier #0) to the previous component carrier, and the total-DAI represents the total number of CBG groups scheduled for the entire component carrier. Here, a CBG group is a predetermined set of S CBGs. According to an embodiment, a TB-based PDSCH in the counter-DAI and total-DAI can be regarded as the same as a CBG-based transmission consisting of S CBGs. That is, it can be assumed that a TB-based PDSCH includes a CBG group. Therefore, even if a TB-based PDSCH is received, the user equipment should feed back an S-bit HARQ-ACK. The S-bit HARQ-ACK can be generated by repeating a 1-bit TB-based HARQ-ACK or by mapping a NACK to the remaining bits. For example, if the total-DAI value is 3, the user equipment can determine that a total of 3*S CBGs have been transmitted over the entire component carrier. Therefore, the user equipment should send a total of 3*S bits of HARQ-ACK. If two TBs are sent in one PDSCH and no space bundling is performed, the user equipment should send a total of 2*3*S bits of HARQ-ACK.

[0319] Table 13 shows the number of CBGs indicated by each DAI value when the total-DAI field and the counter-DAI field consist of two bits. Additionally, Table 14 shows the number of CBGs indicated by each DAI value when the total-DAI field and the counter-DAI field consist of three bits.

[0320] [Table 13]

[0321]

[0322] [Table 14]

[0323]

[0324] In Tables 13 and 14, the subscript c indicates the index of the component carrier (or cell). That is, V DL C-DAI,c It is the counter value of component carrier C - DAI, and V DL T-DAI This is the total-DAI value. According to the signaling methods in Tables 13 and 14, when the total-DAI or counter-DAI value is A, the number of CBGs indicated by the corresponding DAI field is S*(2^B+A). Here, B is the bit width of the counter-DAI or total-DAI. According to an embodiment of the invention, the number S of CBGs included in a CBG group can be expressed in granularity relative to the number of CBGs represented by the counter-DAI or total-DAI.

[0325] According to embodiments of the present invention, the number S of CBGs included in a CBG group can be determined by various methods. According to an embodiment, the value of S can be fixed at S = 2. Preferably, S can be configured with a UE-specific RRC signal. According to another embodiment, S can be determined as the value of the greatest common divisor of the number of CBGs configured in each component carrier. For example, if 2 CBGs are configured in component carrier #0 and 6 CBGs are configured in component carrier #1, it can be set to S = 2. Furthermore, if 4 CBGs are configured in component carrier #0 and 8 CBGs are configured in component carrier #1, it can be set to S = 4.

[0326] According to another embodiment, in a transmission mode where one TB can be transmitted in one component carrier, the value of S can be fixed as S = 2, and in a transmission mode where two TBs can be transmitted in one component carrier, the value of S can be fixed as S = 4. According to yet another embodiment, when all component carriers are configured in a transmission mode where only one TB can be transmitted, S can be determined as the greatest common divisor of the number of CBGs configured in each component carrier. Furthermore, in a transmission mode where two TBs can be transmitted in one component carrier, S can be determined as twice the greatest common divisor of the number of CBGs configured in each component carrier. For example, in a transmission mode where two TBs can be transmitted in one component carrier, if 2 CBGs are configured in component carrier #0 and 6 CBGs are configured in component carrier #1, it can be set to S = 4. Alternatively, if 4 CBGs are configured in component carrier #0 and 8 CBGs are configured in component carrier #1, it can be set to S = 8.

[0327] The bit widths of the Counter-DAI field and the Total-DAI field desired by the user equipment can vary depending on the number S of CBGs included in a CBG group. According to an embodiment, the bit widths of the Counter-DAI field and the Total-DAI field can be set to 2 + ceil(log2(X / S)). In this case, X is the maximum number of CBGs configured for each component carrier of the user equipment. Here, ceil(a) represents the smallest integer greater than or equal to "a". For example, if two component carriers are configured for the user equipment, and the number of CBGs configured in component carrier #0 is 2 and the number of CBGs configured in component carrier #1 is 4, then S = 2. In this case, the bit widths of the Counter-DAI field and the Total-DAI field can be set to 2 + ceil(log2(4 / 2)) = 3 bits. Alternatively, if two component carriers are configured in the user equipment, and the number of CBGs configured in component carrier #0 is 4 and the number of CBGs configured in component carrier #1 is 8, then S = 4. In this case, the bit width of the counter-DAI field and the total-DAI field can be set to 2 + ceil(log2(8 / 4)) = 3 bits respectively.

[0328] refer to Figure 37 The PDSCH can be transmitted to the user equipment via component carriers #0, #1, #3, #4, #5, and #7. In this case, the number of CBGs transmitted via component carriers #0, #1, #3, #4, #5, and #7 can be 2, 4, 6, 8, 2, and 4, respectively. According to an embodiment of the invention, the number S of CBGs included in a CBG group is set to 2, which is the greatest common divisor of the number of CBGs. Therefore, the value of the (counter-DAI, total-DAI) field for each PDSCH of component carriers #0, #1, #3, #4, #5, and #7 can be (0, 13), (1, 13), (3, 13), (6, 13), (10, 13), and (11, 13).

[0329] Figure 38 The illustration shows a HARQ-ACK compression method according to an embodiment of the present invention. If the length of the HARQ-ACK payload that a user equipment configured for CBG-based transmission should send exceeds the maximum transmission capacity of the PUCCH, the HARQ-ACK payload should be compressed to fit the maximum transmission capacity of the PUCCH.

[0330] According to an embodiment of the present invention, a user equipment may send TB-based HARQ-ACKs for some TBs (or PDSCHs) within the entire TB, and send CBG-based HARQ-ACKs for the remaining TBs (or PDSCHs). Reference Figure 38The HARQ-ACK payload of the user equipment can consist of the following three parts. First, the "Header" section informs the method to interpret the following HARQ-ACK payload. More specifically, the "Header" may indicate the index of the TB (or PDSCH) in which the CBG-based HARQ-ACK is sent. Alternatively, the "Header" may indicate the index of the TB (or PDSCH) in which the TB-based HARQ-ACK is sent. Next, the "TB-A / N" field includes the TB-based HARQ-ACK for the TB (or PDSCH) in which the "Header" indicates the sending of the TB-based HARQ-ACK. In this case, the order of the TB-based HARQ-ACK can be set in ascending order of the TB (or PDSCH) counter - DAI value. Next, the "CBG-A / N" field includes the CBG-based HARQ-ACK for the TB (or PDSCH) in which the "Header" indicates the sending of the CBG-based HARQ-ACK. In this case, the order of CBG-based HARQ-ACKs can be set in ascending order of the TB (or PDSCH) counter-DAI value. For reference, if the number of bits in the CBG-based HARQ-ACKs differs for different TBs, a NACK can be appended such that the length of the CBG-based HARQ-ACK payload for each TB is equal to the bit length of the longest CBG-based HARQ-ACK among all CBG-based HARQ-ACKs.

[0331] The header portion can be configured as follows. When sending a HARQ-ACK for a total of X TBs, the user equipment can send a CBG-based HARQ-ACK for c of the X TBs and a TB-based HARQ for the remaining Xc TBs. The method for determining the value of c by the user equipment and the base station will be described later. The header portion represents the information used to select c from the X TBs. The header can consist of a bitmap with a length of X bits. Each bit can indicate whether a TB-based HARQ-ACK or a CBG-based HARQ-ACK is sent for each TB. In another embodiment, the number of cases where c is selected from the X TBs is... here, These are binomial coefficients. Therefore, the number of bits required for the header is... The header can indicate the value. The interpretation of this value is as follows. First, we can assume the value of the "header" is "i". The (i+1)th smallest (or largest) binary sequence can be obtained from a binary sequence of length X where the number of 1s is c and the number of 0s is Xc. In this case, the binary sequence can be interpreted as follows: the index where 1 is located is the index of the TB (or PDSCH) for sending HARQ-ACK based on CBG, and the index where 0 is located is the index of the TB (or PDSCH) for sending HARQ-ACK based on TB. For example, when X = 4 and c = 2, the "header" can indicate a value from 0 to 5. If the value of the "header" is any one of 0 to 5, it can match 0011, 0101, 0110, 1001, 1010, or 1100 respectively. If the value of the "header" is 2, it matches 0110, so CBG-based HARQ-ACK can be sent for the second and third TBs (or PDSCHs), and TB-based HARQ-ACK can be sent for the first and fourth TBs (or PDSCHs).

[0332] According to an embodiment of the present invention, the user equipment and the base station can determine the value of c in the following manner. The base station and the user equipment can know the maximum number of transmitted bits that the PUCCH used for transmitting HARQ-ACK can send. Assume the maximum number of transmitted bits is B. Furthermore, assume the length of the CBG-based HARQ-ACK payload is N. The user equipment and the base station can identify how many TBs (or PDSCHs) are scheduled across the entire component carrier using the total -DAI value. Assume the total number of scheduled TBs (or PDSCHs) is X. In this case, c can be determined as the largest integer satisfying Equation 1 below.

[0333] [Equation 1]

[0334]

[0335] In Equation 1, since the values ​​of X, N, and B are known to both the user equipment and the base station, they can identify the value of c without error. For reference, when the value of c is determined, the length of the HARQ-ACK payload sent by the user equipment is... The base station may always expect a HARQ-ACK payload of the aforementioned length.

[0336] For example, when X = 9, B = 22 and N = 4, c = 2 can be obtained according to Equation 1 above. Therefore, when generating HARQ-ACK, the user equipment can configure N-bit CBG-based HARQ-ACK for 2 out of a total of 9 TBs (or PDSCHs), and can configure 1-bit TB-based HARQ-ACK for the remaining 7 TBs (or PDSCHs). In this case, the base station always expects a 21-bit HARQ-ACK. When the 21-bit HARQ-ACK received by the base station is [001111101100011101010], the interpretation of the HARQ-ACK is as follows. In the HARQ-ACK, because the "header" is Therefore, the value of the "header" is [001111], which is 15. Since the 16th smallest binary sequence in a 15-bit binary sequence is [001000001], CBG-based HARQ-ACKs are sent for the third and ninth TBs (or PDSCHs), and TB-based HARQ-ACKs are sent for the first, second, fourth, fifth, sixth, seventh, and eighth TBs (or PDSCHs). The Xc = 9 - 2 = 7 bits following the "header" is the "TB-A / N" field. The corresponding field value [1011000] indicates TB-based HARQ-ACKs for the first, second, fourth, fifth, sixth, seventh, and eighth TBs (or PDSCHs). The c*N = 2*4 = 8 bits following the "TB-A / N" field is the "CBG-A / N" field. The value of the corresponding field [11101010] indicates the CBG-based HARQ-ACK for the third and ninth TBs (or PDSCHs). That is, the CBG-based HARQ-ACK for the third TB (or PDSCH) is 1110, and the CBG-based HARQ-ACK for the ninth TB (or PDSCH) is 1010.

[0337] Figure 39 and Figure 40 The illustration depicts a method for spatially binding HARQ-ACK according to an embodiment of the present invention. When a user equipment configured with a transmission mode in which two TBs can be transmitted in one PDSCH and configured with CBG-based transmission performs spatial binding, CBG-based HARQ-ACKs should be bound for each TB. Additionally, the user equipment can be configured to spatially bind CBG-based HARQ-ACKs transmitted through different time slots. The method for performing spatial binding according to an embodiment of the present invention is as follows. The method for performing spatial binding is described for reference, but this method can also be used when binding HARQ-ACKs between two different TBs.

[0338] When configuring the same maximum number N of CBGs for each TB, it is assumed that the number of CBGs included in TB#1 is M1, the number of CBGs included in TB#2 is M2, and M1 is greater than or equal to M2. That is, it is assumed that TB#1 contains the same number of CBGs as TB#2 or more. If TB#2 contains more CBGs than TB#1, embodiments of the invention can be applied by changing the indices of TB#1 and TB#2. If the user equipment is configured not to perform bundling, the user equipment should send a total of 2*N bits of HARQ-ACK, N bits for each TB. In this case, if M1 < N, it can be expressed that TB includes M1 CBGs and N-M1 virtual CBGs. Assume that the N-bit HARQ-ACK for TB#1 is [a1, a2, ..., a M1 [b1, b2, ..., bn], and for TB #2, the N-bit HARQ-ACK is [b1, b2, ..., bn]. M2 [x, ..., x]. Here, x is filled with the HARQ-ACK value for the virtual CBG to match the length of the HARQ-ACK payload, and can be mapped to NACK later.

[0339] first, Figure 39 The illustration shows a first embodiment of spatial bundling for HARQ-ACK. More specifically, Figure 39 Figures (a) to (c) illustrate various embodiments of spatial bundling for HARQ-ACK when M1 = N and M2 = 1 to 3. When M1 = N, the index of the CBG to be bundled within the CBGs included in the two TBs can be selected such that the resource elements of the two CBGs overlap as much as possible in the time-frequency domain. This is because the greater the overlap in the time-frequency domain, the higher the expected correlation. More specifically, when M1 = N, the index of the CBG to be bundled within the CBGs included in the two TBs can follow the values ​​in Table 15 based on the values ​​of M1 and M2.

[0340] [Table 15]

[0341] M1＝2 M1＝4 M2＝1 {1} {1} M2＝2 {1，2} {1，4} M2＝3 - {1，2，4} M2＝4 - {1，2，3，4}

[0342] Referring to Table 15, when M1 = 4 and M2 = 2, the value of {1, 4} can be used as the index for executing the bundled CBG. Therefore, referring to... Figure 39(b), the first CBG of TB #2 can be bundled with the first CBG of TB #1, and the first CBG of TB #2 can be bundled with the fourth CBG of TB #1. Additionally, when M1 = 4 and M2 = 3, the values {1, 2, 4} can be obtained as the indices of the CBGs where bundling is performed. Thus, referring to 39(c), the first CBG of TB #2 can be bundled with the first CBG of TB #1, the second CBG of TB #2 can be bundled with the first CBG of TB #1, and the third CBG of TB #2 can be bundled with the fourth CBG of TB #1.

[0343] Table 16 illustrates another method of performing spatial bundling according to the first embodiment above. When M1 = N, the indices of the CBGs where bundling is performed among the CBGs included in the two TBs can follow the values in Table 16 according to the M1 and M2 values.

[0344] [Table 16]

[0345] M1＝2 M1＝4 M2＝1 {1} {1} M2＝2 {1，2} {1，4} M2＝3 - {1，3，4} M2＝4 - {1，2，3，4)

[0346] Referring to Table 16, when M1 = 4 and M2 = 3, the values {1, 3, 4} can be obtained as the indices of the CBGs where bundling is performed. Thus, the first CBG of TB #2 is bound to the first CBG of TB #1, the second CBG of TB #2 is bound to the third CBG of TB #1, and the third CBG of TB #2 can be bound to the fourth CBG of TB #1.

[0347] Next, Figure 40 Illustrates a second embodiment of performing spatial bundling of HARQ-ACK. More specifically, Figure 40 (a) to 40(f) show various embodiments of performing spatial bundling of HARQ-ACK when M1 < N. If M1 < N, some HARQ-ACK bits of TB #2 are preferentially mapped to the HARQ-ACK bits that are not used (or used for virtual CBGs) in TB #1, and bundling of the remaining HARQ-ACK bits of TB #2 and the HARQ-ACK bits of TB #1 can be performed. First, Figure 40 (a) to 40(c) show embodiments where M1 < N and M1 + M2 is less than or equal to N. In this case, the N-bit HARQ-ACK where spatial bundling is performed can consist of the M1-bit HARQ-ACK of TB #1, the M2-bit HARQ-ACK of TB #2, and N - (M1 + M2) bits of NACK. Figure 40Examples (d) to 40(f) illustrate an embodiment where M1 < N and M1 + M2 is greater than N and less than 2*N. In this case, the M1 + M2 - N bits in the HARQ-ACK in which spatial binding is performed can be configured by bundling (i.e., binary AND operation) the M1 + M2 - N bits in the HARQ-ACK of TB#1 and the M1 + M2 - N bits in the HARQ-ACK of TB#2. Furthermore, the 2*N - (M1 + M2) bits in the N-bit HARQ-ACK in which spatial binding is performed can be composed of the remaining N - M2 bits in the HARQ-ACK of TB#1 and the remaining N - M1 bits in the HARQ-ACK of TB#2.

[0348] In a more specific embodiment, [b1,b2,...,b M2 ] can be divided into [b1, b2, ..., b M2-k ] and [b M2-k+1 ,b M2-k+2 ,…,b M2 Here, k satisfies k = N - M1. Additionally, it is possible to find [b1, b2, ..., b] M2-k ] and [a1,a2,…,a M2-k Perform a binary AND operation between [c1, c2, ..., c]. The result is [c1, c2, ..., c]. M2-k The final bundled HARQ-ACK can be constructed by sequentially connecting [c1,c2,…,c…]. M2-k ]、[a M2-k+1 ,a M2-k+1 ,...,a M1 ]、[b M2-k+1 ,b M2-k+2 ,…,b M2 According to an embodiment of the invention, the connection order of HARQ-ACK can be changed. For reference, when the length of the connected HARQ-ACK is less than N bits, x can be appended to the HARQ-ACK to adjust the length to N bits. In this case, x can be mapped to NACK. Finally, when the HARQ-ACK bound thereon is [o1, o2, ..., o...], the connection order can be changed. N When [i] is reached, the HARQ-ACK bits based on the value of index i can be obtained. i As shown in Equation 2.

[0349] [Equation 2]

[0350]

[0351] Here, & represents the binary AND operation. Also, K = N - M1 and α = max{N - (M1 + M2), 0}. In this case, max{s, t} returns the larger number between s and t. Here, x can be mapped to NACK.

[0352] In another embodiment of the invention, when the final HARQ-ACK for binding is [o1,o2,…,o] N When [i] is reached, the HARQ-ACK bits based on the value of index i can be obtained. i As shown in Equation 3.

[0353] [Equation 3]

[0354] If M1+M2≤N,

[0355]

[0356] If N < M1 + M2 < 2 × N,

[0357]

[0358] If M1 + M2 = 2 × N,

[0359] o i ={a i &b i , i = 1, 2, ..., N.

[0360] Here, λ is M1 + M2 - N. Additionally, x can be mapped to NACK.

[0361] Refer to Equations 2 and 3, and Figure 40 The final bundled HARQ-ACK for the two TBs is as follows. (Reference) Figure 40 (a) If the HARQ-ACKs for two TBs are [a1,x,x,x] and [b1,x,x,x], then the final bundled HARQ-ACK is [a1,b1,x,x]. (See reference) Figure 40 (b) If the HARQ-ACKs for the two TBs are [a1,a2,x,x] and [b1,x,x,x], then the final bundled HARQ-ACK is [a1,a2,b1,x]. (See reference) Figure 40 (c) If the HARQ-ACKs for two TBs are [a1,a2,x,x] and [b1,b2,x,x], then the final bundled HARQ-ACK is [a1,a2,b1,b2]. (See reference) Figure 40(d) If the HARQ-ACKs for two TBs are [a1,a2,a3,x] and [b1,x,x,x], then the final bundled HARQ-ACK is [a1,a2,a3,b1]. (See reference) Figure 40 (e) If the HARQ-ACKs for two TBs are [a1,a2,a3,x] and [b1,b2,x,x], then the final bundled HARQ-ACK is [a1&b1,b2,x,x]. Here, & is the binary AND operation. (See reference) Figure 40 (f) If the HARQ-ACKs for two TBs are [a1,a2,a3,x] and [b1,b2,b3,x], then the final bundled HARQ-ACK is [a1&b1,a2&b2,a3,b3]. Furthermore, if the HARQ-ACKs for two TBs are [a1,a2,a3,a4] and [b1,b2,b3,x], then the final bundled HARQ-ACK is [a1&b1,a2&b2,a3&b3,a4].

[0362] Figure 41 and 42 A method for performing HARQ-ACK spatial binding according to an embodiment of the present invention is illustrated in more detail. Figure 41 and 42 In this context, N is the maximum number of CBGs per TB configured by the RRC signal, M1 is the number of CBGs included in TB#1, and M2 is the number of CBGs included in TB#2. Additionally, the HARQ-ACK bit for the i-th CBG in TB#1 is a. i And the HARQ-ACK bit for the i-th CBG of TB#2 is b i In this case, & represents a binary AND operation. Additionally, x can be mapped to NACK.

[0363] According to an embodiment of the present invention, the DCI for a user equipment configured with a transmission mode in which two TBs can be transmitted in one PDSCH and configured with CBG-based transmission can be set as follows. First, it can be assumed that N CBGs are configured for each TB. If the user equipment is configured not to perform spatial bundling, an N-bit CBG Transmission Information (CBGTI) field exists in the user equipment's DCI for each TB to indicate which CBG is transmitted for each TB. Furthermore, a Modulation and Coding Scheme (MCS), Redundancy Version (RV), and New Data Indicator (NDI) are present for each TB. If the CBGTI is all 0 for a TB, it may indicate that the TB was not transmitted. Alternatively, if the CBGTI is all 0 for a TB and the values ​​of the MCS and RV are specific values, it may indicate that the TB was not transmitted. The specific value of the MCS can be 0, and the specific value of the RV can be 1.

[0364] According to another embodiment of the invention, if at least one virtual CBG exists in the two TBs used for bundling, bundling can be performed as follows. First, for the virtual CBG, NACK can be mapped to HARQ-ACK "x". Additionally, Q = min(M1, M2) can be defined. For reference, it is assumed that M1 = 1 when TB#1 is a TB-based transmission, and M2 = 1 when TB#2 is a TB-based transmission. ACK is 1, and NACK is 0. When generating the bundled HARQ-ACK from the HARQ-ACKs for the two TBs, a binary AND operation can be performed on the first to Qth HARQ-ACK bits, and a binary OR operation can be performed on the Q+1 to Nth HARQ-ACK bits. If TB#1 contains 4 CBGs (i.e., M1 = 4) and the number of configured CBGs is 4 (i.e., N = 4), and TB#2 contains 2 CBGs (i.e., M2 = 2) and the number of configured CBGs is 4 (i.e., N = 4), then the HARQ-ACK for TB#1 is [a1, a2, a3, a4], and the HARQ-ACK for TB#2 is [b1, b2, 0, 0]. Additionally, Q = 2. Therefore, a binary AND operation is performed on the first two bits, and a binary OR operation is performed on the following two bits (i.e., as NQ). ​​Thus, the bundled HARQ-ACK is [a1 & b1, a2 & b2, a3|0, a4|0]. Here, & is the binary AND operation, and | is the binary OR operation. For reference, this bundling method can be used in spatial bundling, or it can be used only in bundling within other TBs besides spatial bundling.

[0365] According to another embodiment of the invention, if at least one virtual CBG exists in the two TBs performing the bundling, the bundling can be performed as follows. First, the HARQ-ACK for the virtual CBG is represented by "x", and after bundling, NACK is mapped to "x". When generating the bundled HARQ-ACK from the HARQ-ACKs for the two TBs, a ternary AND operation can be performed on the two HARQ-ACKs. In this case, the truth table of the ternary AND operation is shown in Table 17. After bundling, x can be mapped to NACK. If TB#1 contains 4 CBGs (i.e., M1 = 4) and the number of configured CBGs is 4 (i.e., N = 4), and TB#2 contains 2 CBGs (i.e., M2 = 2) and the number of configured CBGs is 4 (i.e., N = 4), then the HARQ-ACK for TB#1 is [a1, a2, a3, a4], and the HARQ-ACK for TB#2 is [b1, b2, x, x]. Therefore, the HARQ-ACK for performing the binding is [a1\b1, a2\b2, a3\x, a4\x]. The position of the operator \ is shown in Table 17. For reference, this binding method can be used for space binding, or it can be used only for binding in other TBs besides space binding.

[0366] [Table 17]

[0367]

[0368] On the other hand, if the user equipment is configured to perform spatial binding, an N-bit CBGTI field exists in the user equipment's DCI. Furthermore, for each TB, there are MCS, RV, and NDI. The process of determining which CBG the user equipment has received is as follows: The user equipment can identify whether the corresponding TB has been sent by using the values ​​of MCS and RV for each TB. Here, if MCS and RV are specific values, it indicates that the corresponding TB has not yet been sent. For example, the specific value of MCS can be 0, and the specific value of RV can be 1. If there is a transmitted TB, the user equipment can interpret the N-bit CBGTI indicating which CBG of that TB has been sent. That is, if the nth bit of the N-bit CBGTI is 1 (assuming a value of 1 represents transmission), the user equipment can identify that the nth CBG has been sent. When there are two transmitted TBs, the user equipment can identify which CBG was sent in each TB by using the N-bit CBGTI in the same way as the method for performing spatial binding for HARQ-ACK. For example, if the i-th HARQ-ACK bit for spatial binding is calculated by performing a binary AND operation on the k-th CBG of TB#1 and the j-th CBG of TB#2, then when the i-th bit of the N-bit CBGTI of the DCI is 1, it can be indicated that the k-th CBG of TB#1 is sent, and the j-th CBG of TB#2 is sent. As an embodiment of the invention, it is assumed that M1 < N and spatial binding is performed in the same manner as in Equation 4, when the N-bit CBGTI [d1, d2, ..., d...]... N When the i-th bit in the sequence is 1, the following CBG can be identified as being sent.

[0369] [Equation 4]

[0370] If M1+M2≤N,

[0371]

[0372] If N < M1 + M2 < 2 × N,

[0373]

[0374] If M1 + M2 = 2 × N,

[0375] d i =1:{CBG (1) i and CBG (2) i The elements are scheduled, i = 1, 2, ..., N.

[0376] Here, CBG (1) iLet represent the i-th CBG of TB#1, and CBG (2) i M1 represents the i-th CBG in TB#2. M2 and M1 represent the number of CBGs scheduled in TB#1 and TB#2, respectively, which can be identified from the MCS value of each TB in the DCI.

[0377] Figure 43 These are block diagrams illustrating the configurations of a terminal and a base station according to embodiments of the present invention. In embodiments of the present invention, the terminal can be implemented as various types of portable and mobile wireless communication devices or computing devices. The terminal may be referred to as a User Equipment (UE), Station (STA), Mobile Subscriber (MS), etc. Furthermore, in embodiments of the present invention, the base station controls and manages cells corresponding to the service area (e.g., macro cells, femtocells, picocells, etc.) and can perform functions such as transmitting signals, allocating channels, monitoring channels, self-diagnostics, relaying, etc. The base station may be referred to as a Next Generation Node B (gNB) or Access Point (AP).

[0378] As illustrated, a user equipment 100 according to an embodiment of the present invention may include a processor 110, a communication module 120, a memory 130, a user interface unit 140, and a display unit 150.

[0379] First, the processor 110 can execute various commands or programs and process the internal data of the user equipment 100. Furthermore, the processor 110 can control the overall operation of each unit within the user equipment 100, and the data transmission and reception between control units. In this case, the processor 110 can be configured to perform operations according to the embodiments described herein. For example, the processor 110 can receive time slot configuration information, determine a time slot configuration based on the time slot configuration information, and perform communication according to the determined time slot configuration.

[0380] Next, the communication module 120 may be an integrated module that performs wireless communication using a wireless communication network and wireless LAN access using a wireless LAN. For this purpose, the communication module 120 may include multiple network interface cards (NICs), such as cellular communication interface cards 121 and 122 and an unlicensed band communication interface card 123, either internally or externally. Although the communication module 120 is illustrated as an integrated module in the figures, unlike the figures, each network interface card may be arranged independently according to circuit configuration or purpose.

[0381] Cellular communication interface card 121 can transmit and receive wireless signals with at least one of base station 200, external device, and server using a mobile communication network, and can provide cellular communication services via a first frequency band based on commands from processor 110. According to an embodiment, cellular communication interface card 121 may include at least one NIC module using a frequency band below 6 GHz. At least one NIC module of cellular communication interface card 121 can independently perform cellular communication with at least one of base station 200, external device, and server according to a cellular communication standard or protocol for a frequency band below 6 GHz supported by the corresponding NIC module.

[0382] Cellular communication interface card 122 can transmit and receive wireless signals using a mobile communication network and at least one of base station 200, external devices, and servers, and can provide cellular communication services via a second frequency band based on commands from processor 110. According to an embodiment, cellular communication interface card 122 may include at least one NIC module using a frequency band above 6 GHz. At least one NIC module of cellular communication interface card 122 can independently perform cellular communication with at least one of base station 200, external devices, and servers according to a cellular communication standard or protocol in a frequency band above 6 GHz supported by the corresponding NIC module.

[0383] The unlicensed frequency band communication interface card 123 transmits and receives wireless signals through at least one of the base station 200, external devices, and servers by using a third frequency band, which is an unlicensed frequency band, and provides unlicensed frequency band communication services through a second frequency band based on commands from the processor 110. The unlicensed frequency band communication interface card 123 may include at least one NIC module using an unlicensed frequency band. For example, the unlicensed frequency band may be a 2.4 GHz or 5 GHz band. At least one NIC module of the unlicensed frequency band communication interface card 123 can independently perform wireless communication with at least one of the base station 200, external devices, and servers according to the unlicensed frequency band communication standard or protocol supported by the corresponding NIC module.

[0384] Next, the memory 130 stores the control program used in the user equipment 100, as well as various data thereunder. Such a control program may include predetermined programs necessary for the user equipment 100 to perform wireless communication with at least one of the base station 200, external devices, and servers.

[0385] Next, the user interface 140 includes various types of input / output devices provided in the user equipment 100. That is, the user interface 140 can use various input devices to receive user input, and the processor 110 can control the user equipment 100 based on the received user input. In addition, the user interface 140 can use various output devices to execute output based on commands from the processor 110.

[0386] Next, the display unit 150 outputs various images on the display screen. The display unit 150 can output various display objects, such as content executed by the processor 110 or a user interface, based on the control commands of the processor 110.

[0387] In addition, the base station 200 according to an embodiment of the present invention may include a processor 210, a communication module 220 and a memory 230.

[0388] First, the processor 210 can execute various commands or programs and process the internal data of the base station 200. Furthermore, the processor 210 can control the overall operation of each unit including the base station 200 and control data transmission and reception between the units. In this case, the processor 210 can be configured to perform operations according to the embodiments described in the present invention. For example, the processor 210 can transmit time slot configuration information using signals and perform communication according to the time slot configuration transmitted using signals.

[0389] Next, the communication module 220 may be an integrated module that performs wireless communication using a wireless communication network and wireless LAN access using a wireless LAN. For this purpose, the communication module 220 may include multiple network interface cards, such as cellular communication interface cards 221 and 222 and an unlicensed band communication interface card 223, either internally or externally. Although the communication module 220 is illustrated as an integrated module in the figures, unlike the figures, each network interface card may be arranged independently depending on the circuit configuration or purpose.

[0390] Cellular communication interface card 221 can transmit and receive wireless signals with at least one of the user equipment 100, external devices, and servers using a mobile communication network, and can provide cellular communication services via a first frequency band based on commands from processor 210. According to an embodiment, cellular communication interface card 221 may include at least one NIC module using a frequency band below 6 GHz. At least one NIC module of cellular communication interface card 221 can independently perform cellular communication with at least one of the user equipment 100, external devices, and servers according to a cellular communication standard or protocol in a frequency band below 6 GHz supported by the corresponding NIC module.

[0391] Cellular communication interface card 222 can transmit and receive wireless signals using a mobile communication network and at least one of user equipment 100, external devices, and servers, and can provide cellular communication services via a second frequency band based on commands from processor 210. According to an embodiment, cellular communication interface card 222 may include at least one NIC module using a frequency band above 6 GHz. At least one NIC module of cellular communication interface card 222 can independently perform cellular communication with at least one of user equipment 100, external devices, and servers according to a cellular communication standard or protocol in a frequency band above 6 GHz supported by the corresponding NIC module.

[0392] The unlicensed frequency band communication interface card 223 transmits and receives wireless signals with at least one of the user equipment 100, external devices, and servers by using a third frequency band that is an unlicensed frequency band, and provides unlicensed frequency band communication services based on commands from the processor 210. The unlicensed frequency band communication interface card 223 may include at least one NIC module that uses an unlicensed frequency band. For example, the unlicensed frequency band may be a 2.4 GHz or 5 GHz band. At least one NIC module of the unlicensed frequency band communication interface card 223 can independently or dependently perform wireless communication with at least one of the user equipment 100, external devices, and servers according to the unlicensed frequency band communication standard or frequency protocol supported by the corresponding NIC module.

[0393] Figure 43 The user equipment 100 and base station 200 illustrated herein are block diagrams according to an embodiment of the present invention, wherein the separately shown blocks represent logically different elements of the devices. Therefore, depending on the device design, the elements of the aforementioned devices can be mounted on one or more chips. Furthermore, some components of the user equipment 100, such as the user interface 140, display unit 150, etc., can be selectively provided in the user equipment 100. Additionally, the user interface 140, display unit 150, etc., can be separately provided in the base station 200 as needed.

[0394] The foregoing description of the present invention is intended as an example, and those skilled in the art will understand that the invention can be readily modified in other specific forms without altering its technical concept and / or essential characteristics. Therefore, it should be understood that the above embodiments are exemplary in all respects and not restrictive. For example, each component described as a single type can be implemented in a distributed manner, and similarly, components described as distributed can be implemented in a composite manner.

[0395] The scope of this invention is shown by the appended claims rather than the foregoing description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be interpreted as being included within the scope of this invention.

Claims

1. A user equipment configured to operate in a wireless communication system, comprising: Communication module; and A processor configured to control the communication module. The processor is configured as follows: Receive multiple downlink control information (DCI) messages used for scheduling the Physical Downlink Shared Channel (PDSCH). Each DCI corresponds to either a first format including a counter downlink allocation index DAI, or a second format including the counter DAI and the total DAI. Each of the plurality of DCIs schedules PDSCH reception based on transport block TB or PDSCH reception based on code block group CBG on the corresponding cell in the plurality of cells. The CBG-based PDSCH reception and the TB-based PDSCH reception are performed based on the multiple DCIs, and For the multiple cells, a HARQ-ACK codebook is generated, including a first HARQ-ACK bit sequence for the TB-based PDSCH reception and a second HARQ-ACK bit sequence for the CBG-based PDSCH reception. Wherein, at least one of the counters DAI included in each of the plurality of DCIs or the total DAI is respectively applied to each of the first HARQ-ACK bit sequence received by PDSCH based on TB or the second HARQ-ACK bit sequence received by PDSCH based on CBG. Among them, the plurality of cells includes at least one CBG cell configured with CBG-based PDSCH transmission, and In each of at least one CBG cell, the TB-based PDSCH reception or the CBG-based PDSCH reception is performed based on the first or second format of the corresponding DCI among a plurality of DCIs.

2. The user equipment according to claim 1, wherein, The processor is further configured to: Send HARQ-ACK information including the HARQ-ACK codebook. The HARQ-ACK codebook is generated by appending the second HARQ-ACK bit sequence to the first HARQ-ACK bit sequence.

3. The user equipment according to claim 1, in, The plurality of cells further includes at least one TB cell configured with TB-based PDSCH transmission, and Specifically, in the at least one TB cell, only TB-based PDSCH reception is performed.

4. The user equipment according to claim 1, wherein, The processor is further configured to: Receive configuration information for configuring transmission methods in multiple cells. Based on the configuration information, each of the plurality of cells is configured for CBG-based transmission or TB-based PDSCH transmission.

5. The user equipment according to claim 1, in, Each bit of the first HARQ-ACK bit sequence is generated for each transport block.

6. The user equipment according to claim 1, in, The second HARQ-ACK bit sequence used for the CBG-based PDSCH reception includes 'N' HARQ-ACK bits, and Here, 'N' is related to the number of CBGs configured for the user equipment.

7. The user equipment according to claim 1, in, The counter DAI is used to identify the cumulative number of scheduled PDSCHs, and The total DAI is used to identify the total number of PDSCHs that are scheduled.

8. A wireless communication method in a wireless communication system, comprising: Receive multiple downlink control information (DCI) messages used for scheduling the Physical Downlink Shared Channel (PDSCH). in, Each DCI corresponds to either a first format including a counter downlink allocation index DAI, or a second format including the counter DAI and the total DAI. Each of the plurality of DCIs schedules PDSCH reception based on transport block TB or PDSCH reception based on code block group CBG on the corresponding cell in the plurality of cells. The CBG-based PDSCH reception and the TB-based PDSCH reception are performed based on the multiple DCIs, and For the multiple cells, a HARQ-ACK codebook is generated, including a first HARQ-ACK bit sequence for the TB-based PDSCH reception and a second HARQ-ACK bit sequence for the CBG-based PDSCH reception. Wherein, at least one of the counters DAI included in each of the plurality of DCIs or the total DAI is respectively applied to each of the first HARQ-ACK bit sequence received by PDSCH based on TB or the second HARQ-ACK bit sequence received by PDSCH based on CBG. Among them, the plurality of cells includes at least one CBG cell configured with CBG-based PDSCH transmission, and In each of at least one CBG cell, the TB-based PDSCH reception or the CBG-based PDSCH reception is performed based on the first or second format of the corresponding DCI among a plurality of DCIs.

9. The method according to claim 8, wherein, The method further includes: Send HARQ-ACK information including the HARQ-ACK codebook. The HARQ-ACK codebook is generated by appending the second HARQ-ACK bit sequence to the first HARQ-ACK bit sequence.

10. The method according to claim 8, in, The plurality of cells further includes at least one TB cell configured with TB-based PDSCH transmission, and Specifically, in the at least one TB cell, only TB-based PDSCH reception is performed.

11. The method according to claim 8, wherein, The method further includes: Receive configuration information for configuring transmission methods in multiple cells. Based on the configuration information, each of the plurality of cells is configured for CBG-based transmission or TB-based PDSCH transmission.

12. The method according to claim 8, in, Each bit of the first HARQ-ACK bit sequence is generated for each transport block.

13. The method according to claim 8, in, The second HARQ-ACK bit sequence used for the CBG-based PDSCH reception includes 'N' HARQ-ACK bits, and Here, 'N' is related to the number of CBGs configured for the user equipment.

14. The method according to claim 8, in, The counter DAI is used to identify the cumulative number of scheduled PDSCHs, and The total DAI is used to identify the total number of PDSCHs that are scheduled.

Images