CN117256114A

CN117256114A - Method, apparatus and system for transmitting HARQ-ACK codebook in wireless communication system

Info

Publication number: CN117256114A
Application number: CN202280032196.5A
Authority: CN
Inventors: 崔庚俊; 卢珉锡; 石根永; 郭真三
Original assignee: Wilus Institute of Standards and Technology Inc
Current assignee: Wilus Institute of Standards and Technology Inc
Priority date: 2021-03-31
Filing date: 2022-03-31
Publication date: 2023-12-19

Abstract

The present invention relates to a wireless communication system, and more particularly, to a method and apparatus thereof, the method comprising the steps of: receiving a PDCCH for multi-slot scheduling; determining PDSCH candidates for each slot based on information in the PDCCH; and transmitting a semi-static HARQ-ACK codebook based on the determined PDSCH candidates for each slot.

Description

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

Technical Field

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

Background

The 3GPP LTE (-a) defines uplink/downlink physical channels to transmit physical layer signals. For example, a Physical Uplink Shared Channel (PUSCH) as a physical channel for transmitting data through an uplink, a Physical Uplink Control Channel (PUCCH) for transmitting a control signal, a Physical Random Access Channel (PRACH), etc., are defined, and there are a Physical Downlink Shared Channel (PDSCH) for transmitting data to a downlink, a Physical Control Format Indicator Channel (PCFICH) for transmitting an L1/L2 control signal, a Physical Downlink Control Channel (PDCCH), a physical hybrid ARQ indicator channel (PHICH), etc.

The downlink control channel (PDCCH/EPDCCH) among the above-mentioned channels is a channel for a base station to transmit uplink/downlink scheduling assignment control information, uplink transmission power control information, and other control information to one or more user equipments. Since the resources available through the PDCCH that can be transmitted at one time by the base station are limited, different resources cannot be allocated to each user equipment, and control information should be transmitted to any user equipment through the shared resources. For example, in 3GPP LTE (-a), 4 Resource Elements (REs) may be grouped to form a Resource Element Group (REG), 9 Control Channel Elements (CCEs) may be generated, resources capable of combining and transmitting one or more CCEs may be notified to user equipment, and multiple user equipment may share and use CCEs. Here, the number of CCEs combined is referred to as a CCE combining level, and the resource to which CCEs are allocated is referred to as a search space according to the possible CCE combining level. The search space may include a common search space defined for each base station and a terminal-specific or UE-specific search space defined for each user equipment. The user equipment performs decoding on the number of cases of all possible CCE combinations in the search space, and can identify whether the user equipment belongs to the PDCCH through a User Equipment (UE) identifier included in the PDCCH. Therefore, such an operation of the user equipment requires a long time to decode the PDCCH and inevitably results in a large amount of energy consumption.

There is an ongoing effort to develop an improved 5G communication system or pre-5G communication system to meet the increasing wireless data service demand after commercialization of the 4G communication system. For this reason, the 5G communication system or pre-5G communication system is referred to as a super 4G network communication system or post-LTE system. It is considered to implement a 5G communication system in an ultra-high frequency (millimeter wave) band (e.g., 60GHz band) to achieve a high data transmission rate. In order to reduce radio propagation path loss and increase transmission distance of radio waves in ultra-high frequency bands, beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive antenna techniques are discussed in the field of 5G communication systems. Further, in order to improve a network of a system, technologies such as an advanced small cell, a cloud radio access network (cloud RAN), a super-dense network, device-to-device communication (D2D), a wireless backhaul, a mobile network, cooperative communication, cooperative multipoint (CoMP), interference cancellation, and the like are developed in the field of 5G communication systems. Furthermore, hybrid FSK and QAM modulation (FQAM) and Sliding Window Superposition Coding (SWSC), which is an Advanced Coding Modulation (ACM) scheme, and Filter Bank Multicarrier (FBMC), non-orthogonal multiple access (NOMA), and Sparse Code Multiple Access (SCMA) access technologies, which are advanced access technologies, are being developed in the field of 5G systems.

Meanwhile, in human-centric connection networks where humans generate and consume information, the internet has evolved into an internet of things (IoT) network that exchanges information between distributed components such as objects. Internet of everything (IoE) technology combining IoT technology with big data processing technology through a connection with a cloud server is also emerging. In order to implement IoT, technical elements such as sensing technology, wired/wireless communication and network infrastructure, service interface technology, and security technology are required, so that technologies such as sensor networks, machine-to-machine (M2M), and machine-type communication (MTC) have been studied in recent years to connect between objects. In an IoT environment, intelligent Internet Technology (IT) services can be provided that collect and analyze data generated from networked objects to create new value in human life. Through the fusion and mixing of existing Information Technology (IT) and various industries, ioT can be applied in fields such as smart homes, smart buildings, smart cities, smart cars or networked cars, smart grids, healthcare, smart appliances and advanced medical services.

Here, various attempts have been made to apply a 5G communication system to IoT networks. For example, technologies such as sensor networks, machine-to-machine (M2M), and Machine Type Communication (MTC) are implemented by 5G communication technologies, i.e., beamforming, MIMO, array antennas, and so on. Applying a cloud radio access network (cloud RAN) as the big data processing technology described above may be an example of a fusion of 5G technology and IoT technology.

In general, mobile communication systems have been developed to provide voice services while protecting user activities. However, the field of mobile communication systems is extended not only to voice services but also to data services, and has been developed so far to provide high-speed data services. However, in the mobile communication system currently being used for providing services, a resource shortage phenomenon occurs and a user needs a higher-speed service. Therefore, a more developed wireless communication system is required.

As described above, with the advent of new applications such as real-time control, haptic internet, and the like, the time delay of data transmission is required to be lower, and the time delay required for 5G data is expected to be reduced to 1ms. The goal of 5G is to provide a reduction in data latency of about 10 times over the prior art. To solve these problems, it is desirable to propose a 5G communication system that uses mini-slots (mini-slots) with shorter TTI intervals (e.g., 0.2 ms) in addition to existing slots (or subframes).

Disclosure of Invention

Technical problem

An object of the present invention is to provide a method and apparatus for efficiently transmitting and receiving signals in a wireless communication system. Furthermore, an object of the present invention is to provide a method and apparatus for efficiently transmitting a HARQ-ACK codebook in a wireless communication system. Here, the wireless communication system can include a 3 GPP-based wireless communication system, for example, a 3GPP NR-based wireless communication system.

The objects of the present invention are not limited to those specifically described herein.

Technical proposal

According to an aspect of the present invention, there is provided a user equipment for use in a wireless communication system, the user equipment comprising a communication module; and a processor controlling the communication module, wherein the processor is configured to receive a Physical Downlink Control Channel (PDCCH) with the following information:

-index information indicating one entry in a Time Domain Resource Allocation (TDRA) table for Physical Downlink Shared Channel (PDSCH) allocation, and

-indicating a K1-set { K1 for PDSCH-to-HARQ (hybrid automatic repeat and request) slot timing _i Timing information of one value of (i=1, 2.); determining a time slot n-K1 for all K1 values in the K1-set when the time slot n is indicated by the timing information _i PDSCH candidates of (a); and transmitting a semi-static HAR in the slot n based on the determined PDSCH candidates for each slotA Q-ACK codebook, and when determining the PDSCH candidate, replacing the K1-set by a union of the subsequent K-sets #i based on at least one entry in the TDRA table associated with a plurality of PDCCH-to-PDSCH slot timing K0 values,

-K-set #i: { K1 _i +d1,K1 _i +d ₂ ,…,K1 _i +d _N },

Wherein d spans all entries in the TDRA table based on the plurality of PDCCH-to-PDSCH timing K0 values _k (k=1, 2,.,. N) corresponds to a slot index difference between a last slot to which a PDSCH can be allocated and a kth slot to which the PDSCH can be allocated.

According to another aspect of the present invention, there is provided a method for use by a user equipment in a wireless communication system, the method comprising receiving a Physical Downlink Control Channel (PDCCH) with the following information:

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

-K-set #i: { K1 _i +d ₁ ,K1 _i +d ₂ ,…,K1 _i +d _N },

According to yet another aspect of the present invention, there is provided a base station for use in a wireless communication system, the base station comprising a communication module; and a processor controlling the communication module, wherein the processor is configured to transmit a Physical Downlink Control Channel (PDCCH) with the following information:

-indicating a K1-set { K1 for PDSCH-to-HARQ (hybrid automatic repeat and request) slot timing _i Timing information of one value of (i=1, 2.); determining a time slot n-K1 for all K1 values in the K1-set when the time slot n is indicated by the timing information _i PDSCH candidates of (a); and receiving a semi-static HARQ-ACK codebook in the slot n based on the determined PDSCH candidate for each slot, and when determining the PDSCH candidate, replacing the K1-set by a union of the subsequent K-sets #i based on at least one entry in the TDRA table associated with a plurality of PDCCH-to-PDSCH slot timing K0 values,

-K-set #i: { K1 _i +d ₁ ,K1 _i +d ₂ ,…,K1 _i +d _N },

According to yet another aspect of the present invention, there is provided a method for use by a base station in a wireless communication system, the method comprising transmitting a Physical Downlink Control Channel (PDCCH) with the following information:

-indicating a K1-set { K1 for PDSCH-to-HARQ (hybrid automatic repeat and request) slot timing _i One of (i=1, 2,.)Timing information of the individual values; determining a time slot n-K1 for all K1 values in the K1-set when the time slot n is indicated by the timing information _i PDSCH candidates of (a); and receiving a semi-static HARQ-ACK codebook in said time slot n based on said determined PDSCH candidate for each time slot, and when said PDSCH candidate is determined, replacing the K1-set by a union of subsequent K-sets #i based on at least one entry in said TDRA table associated with a plurality of PDCCH-to-PDSCH slot timing K0 values,

-K-set #i: { K1 _i +d ₁ ,K1 _i +d ₂ ,…,K1 _i +d _N },

Preferably, a subcarrier spacing (SCS) applied to a slot in which the PDCCH is transmitted is the same as the SCS applied to a slot in which the semi-static HARQ-ACK codebook is transmitted.

Preferably, with respect to the determined PDSCH candidate of each slot, a plurality of HARQ-ACK opportunities are sequentially allocated to non-overlapping PDSCH candidates with reference to the PDSCH candidate having the earliest last symbol, and the semi-static HARQ-ACK codebook is configured based on the plurality of HARQ-ACK opportunities.

Preferably, when a time domain bundling is applied to the semi-static HARQ-ACK codebook, the plurality of HARQ-ACK opportunities are allocated based on the PDSCH candidates of the last slot to which the PDSCH of each bundling group can be allocated, based on each entry in the TDRA table.

Preferably, the wireless communication system comprises a third generation partnership project (3 GPP) New Radio (NR) based wireless communication system.

Advantageous effects

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

The effects obtainable from the present invention are not limited to the above-described effects, and other effects not mentioned will be clearly understood by those skilled in the art from the following description.

Drawings

Fig. 1 illustrates an example of a radio frame structure used in a wireless communication system.

Fig. 2 illustrates an example of a Downlink (DL)/Uplink (UL) slot structure in a wireless communication system.

Fig. 3 is a diagram for explaining physical channels used in a 3GPP system and a typical signal transmission method using the same.

Fig. 4 illustrates SS/PBCH blocks for initial cell access in a 3GPP NR system.

Fig. 5 illustrates a procedure for transmitting control information and control channels in a 3GPP NR system.

Fig. 6 illustrates a control resource set (CORESET) in which a Physical Downlink Control Channel (PDCCH) may be transmitted in a 3GPP NR system.

Fig. 7 illustrates a method for configuring a PDCCH search space in a 3GPP NR system.

Fig. 8 is a conceptual diagram illustrating carrier aggregation.

Fig. 9 is a diagram for explaining signal carrier communication and multicarrier communication.

Fig. 10 is a diagram showing an example in which a cross-carrier scheduling technique is applied.

Fig. 11 illustrates scheduling of a Physical Downlink Shared Channel (PDSCH).

Fig. 12 illustrates scheduling of a Physical Uplink Shared Channel (PUSCH).

Fig. 13 illustrates scheduling of PUSCH and Physical Uplink Control Channel (PUCCH).

Fig. 14 illustrates scheduling of PDSCH according to multi-slot scheduling.

Fig. 15 illustrates PUCCH transmission in one slot according to multi-slot scheduling.

Fig. 16 illustrates PUCCH transmissions in two or more slots according to multi-slot scheduling.

Fig. 17 illustrates a conventional type-1 hybrid automatic repeat request acknowledgement (HARQ-ACK) codebook generation method.

Fig. 18 illustrates PDSCH candidates corresponding to HARQ-ACKs when PUCCH is transmitted in slot n.

Fig. 19 is a diagram illustrating HARQ-ACK opportunities according to an example of the invention.

Fig. 20 illustrates an example HARQ-ACK codebook generation process according to the present invention.

Fig. 21 illustrates a time domain bundling window.

Fig. 22 illustrates a representative PDSCH according to a time domain bundling window.

Fig. 23 illustrates HARQ-ACK occasions according to a time domain bundling window.

Fig. 24 illustrates a HARQ-ACK transmission procedure according to an example of the present invention.

Fig. 25 is a diagram showing a configuration of a UE and a base station according to an embodiment of the present disclosure.

Detailed Description

The terms used in the specification adopt general terms currently widely used as much as possible by considering functions in the present invention, but may be changed according to the intention, habit, and appearance of new technology of those skilled in the art. In addition, in a specific case, there are terms arbitrarily selected by the applicant, and in this case, the meaning thereof will be described in the corresponding description section of the present invention. Therefore, it is intended that the terms used in the specification be construed not only based on the names of the terms but also based on the essential meanings of the terms and contents throughout the specification.

Throughout the specification and claims which follow, when an element is described as being "connected" to another element, the element may be "directly connected" to the other element or "electrically connected" to the other element through a third element. In addition, unless explicitly described to the contrary, the word "comprising" will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. Furthermore, in some exemplary embodiments, limitations such as "greater than or equal to" or "less than or equal to" based on a particular threshold, respectively, may be appropriately replaced with "greater than" or "less than," respectively.

The following techniques may be used in various wireless access systems: such as Code Division Multiple Access (CDMA), frequency Division Multiple Access (FDMA), time Division Multiple Access (TDMA), orthogonal Frequency Division Multiple Access (OFDMA), single carrier-FDMA (SC-FDMA), and the like. CDMA may be implemented by wireless technology such as Universal Terrestrial Radio Access (UTRA) or CDMA 2000. TDMA may be implemented by wireless technologies such as global system for mobile communications (GSM)/General Packet Radio Service (GPRS)/enhanced data rates for GSM evolution (EDGE). OFDMA may be implemented by wireless technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, evolved UTRA (E-UTRA), and the like. UTRA is part of Universal Mobile Telecommunications System (UMTS). The third generation partnership project (3 GPP) Long Term Evolution (LTE) is part of evolved UMTS (E-UMTS) using evolved UMTS terrestrial radio access (E-UTRA), and LTE-advanced (a) is an evolved version of 3GPP LTE. The 3GPP New Radio (NR) is a system designed separately from LTE/LTE-a and is a system for supporting an enhanced mobile broadband (eMBB), ultra-reliable low-delay communication (URLLC), and large-scale machine type communication (mctc) service, which are requirements of IMT-2020. For clarity of description, the 3GPP NR is mainly described, but the technical ideas of the present invention are not limited thereto.

Unless otherwise specified herein, a base station may include a next generation node B (gNB) defined in a 3GPP NR. Further, unless specified otherwise, the terminal may include a User Equipment (UE). Hereinafter, to assist understanding of the description, each content is described individually by an embodiment, but each embodiment may be used in combination. In this specification, the configuration of the UE may indicate the configuration by the base station. In more detail, the base station may configure values of parameters used in operation of the UE or the wireless communication system by transmitting channels or signals to the UE.

Referring to fig. 1, a radio frame used in a 3gpp NR systemThe (or radio frame) may have a duration of 10ms (Δf) _max N _f /100)*T _c ) Is a length of (c). Further, the radio frame includes 10 Subframes (SFs) 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 may be allocated to 10 subframes within one radio frame, respectively. Each subframe is 1ms in length and may include one or more slots according to a subcarrier spacing. More specifically, in 3GPP NR systems, the subcarrier spacing that can be used is 15 x 2 ^μ kHz, and μ can have values of μ=0, 1, 2, 3, 4 as subcarrier spacing configurations. That is, 15kHz, 30kHz, 60kHz, 120kHz, and 240kHz may be used for subcarrier spacing. One subframe of length 1ms may include 2 ^μ And each time slot. In this case, each time slot has a length of 2 ^-μ ms. Can be from 0 to 2 ^μ The numbers of-1 are respectively allocated to 2 in one subframe ^μ And each time slot. In addition, it is possible to add from 0 to 10 x 2 ^μ The numbers of-1 are respectively assigned to time slots within one radio frame. The time resources may be distinguished by at least one of a radio frame number (also referred to as a radio frame index), a subframe number (also referred to as a subframe index), and a slot number (or slot index).

Fig. 2 illustrates an example of a Downlink (DL)/Uplink (UL) slot structure in a wireless communication system. In particular, fig. 2 shows the structure of a resource grid of a 3GPP NR system.

There is one resource grid per antenna port. Referring to fig. 2, a slot includes a plurality of Orthogonal Frequency Division Multiplexing (OFDM) symbols in a time domain and a plurality of Resource Blocks (RBs) in a frequency domain. One OFDM symbol also refers to one symbol interval. OFDM symbols may be abbreviated as symbols unless otherwise specified. One RB includes 12 consecutive subcarriers in the frequency domain. Referring to fig. 2, the signal transmitted from each slot may be composed of N ^size,μ _grid,x *N ^RB _sc Sub-carriers and N ^slot _symb A resource grid of OFDM symbols. Here, when the letterThe number is x=dl when the signal is DL and x=ul when the signal is UL. N (N) ^size,μ _grid,x Represents the number of Resource Blocks (RBs) (x is DL or UL) according to the subcarrier spacing component μ, and N ^slot _symb Representing the number of OFDM symbols in the slot. N (N) ^RB _sc Is the number of subcarriers constituting one RB and N ^RB _sc =12. The OFDM symbol may be referred to as a cyclic shift OFDM (CP-OFDM) symbol or a discrete fourier transform spread OFDM (DFT-s-OFDM) symbol according to a multiple access scheme.

The number of OFDM symbols included in one slot may vary according to the length of a Cyclic Prefix (CP). For example, in the case of a normal CP, one slot includes 14 OFDM symbols, but in the case of an extended CP, one slot may include 12 OFDM symbols. In a particular embodiment, extended CP can only be used at 60kHz subcarrier spacing. In fig. 2, one slot is configured with 14 OFDM symbols as an example for convenience of description, but embodiments of the present disclosure may be applied to slots having different numbers of OFDM symbols in a similar manner. Referring to fig. 2, each OFDM symbol includes N in the frequency domain ^size,μ _grid,x *N ^RB _sc Sub-carriers. The types of subcarriers may be divided into data subcarriers for data transmission, reference signal subcarriers for transmission of reference signals, and guard bands. The carrier frequency is also referred to as the center frequency (fc).

One RB may be composed of N in the frequency domain ^RB _sc (e.g., 12) consecutive sub-carriers. For reference, a resource configured with one OFDM symbol and one subcarrier may be referred to as a Resource Element (RE) or tone. Thus, one RB can be configured with N ^slot _symb *N ^RB _sc And resource elements. Each resource element in the resource grid can be uniquely defined by a pair of indices (k, l) in one slot. k may be from 0 to N in the frequency domain ^size,μ _grid,x *N ^RB _sc -1, and l may be from 0 to N in the time domain ^slot _symb -1 assigned index.

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

Each symbol of a radio frame used in Time Division Duplex (TDD) or unpaired spectrum may be configured with at least one of a DL symbol, an UL symbol, and a flexible symbol. A radio frame used as a DL carrier in Frequency Division Duplex (FDD) or paired spectrum may be configured with DL symbols or flexible symbols, and a radio frame used as an UL carrier may be configured with UL symbols or flexible symbols. In DL symbols, DL transmission is possible, but UL transmission is not possible. In UL symbols, UL transmission is possible, but DL transmission is not possible. The flexible symbols may be determined to be used as DL or UL according to the signal.

Information about the type of each symbol, i.e., information representing any one of DL symbols, UL symbols, and flexible symbols, may be configured with a cell-specific or common Radio Resource Control (RRC) signal. Furthermore, information on the type of each symbol may be additionally configured with a UE-specific or dedicated RRC signal. The base station informs i) a period of a cell-specific slot configuration, ii) a number of slots having only DL symbols from a beginning of the period of the cell-specific slot configuration, iii) a number of DL symbols from a first symbol of a slot immediately after the slot having only DL symbols, iv) a number of slots having only UL symbols from an end of the period of the cell-specific slot configuration, and v) a number of UL symbols from a last symbol of the slot immediately before the slot having only UL symbols, by using a cell-specific RRC signal. Here, the symbol not configured with any one of the UL symbol and the DL symbol is a flexible symbol.

When the information on the symbol type is configured with a UE-specific RRC signal, the base station may signal whether the flexible symbol is a DL symbol or an UL symbol in a cell-specific RRC signal. In this case, the UE-specific RRC signal cannot change the DL symbol or UL symbol configured with the cell-specific RRC signal to another symbol type. UE-specific RRC signaling The number may signal N of the corresponding time slot of each time slot ^slot _symb The number of DL symbols among the symbols and the N of the corresponding slot ^slot _symb The number of UL symbols among the symbols. In this case, DL symbols of the slot may be sequentially configured with first to i-th symbols of the slot. In addition, UL symbols of the slot may be successively configured with j-th to last symbols of the slot (where i<j) A. The invention relates to a method for producing a fibre-reinforced plastic composite In a slot, a symbol that is not configured with any one of UL symbols and DL symbols is a flexible symbol.

The symbol type configured using the above-described RRC signal may be referred to as a semi-static DL/UL configuration. In a semi-static DL/UL configuration that is pre-configured with RRC signals, flexible symbols may be indicated as DL symbols, UL symbols, or flexible symbols through dynamic Slot Format Information (SFI) transmitted on a physical DL control channel. In this case, the DL symbol or UL symbol configured with the RRC signal is not changed to another symbol type. Table 1 illustrates dynamic SFIs that a base station may indicate to a UE.

TABLE 1

In table 1, D represents a DL symbol, U represents an UL symbol, and X represents a flexible symbol. As shown in table 1, at most two DL/UL switches are allowed in 1 slot.

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

If the power of the UE is turned on or the UE camps on a new cell, the UE performs an initial cell search (S101). Specifically, the UE may synchronize with the BS in the initial cell search. To this end, the UE may receive a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS) from the base station to synchronize with the base station and obtain information such as a cell ID. Thereafter, the UE can receive a Physical Broadcast Channel (PBCH) from the base station and obtain broadcast information in the cell.

Upon completion of the initial cell search, the UE receives a Physical Downlink Shared Channel (PDSCH) according to a Physical Downlink Control Channel (PDCCH) and information in the PDCCH, so that the UE can obtain more specific system information than that obtained through the initial cell search (S102).

When the UE initially accesses the base station or does not have radio resources for signal transmission (i.e., the UE is in rrc_idle mode), the UE may perform a random access procedure for the base station (operations S103 to S106). First, the UE can transmit a preamble through a Physical Random Access Channel (PRACH) (S103) and receive a response message for the preamble from the base station through a PDCCH and a corresponding PDSCH (S104). When the UE receives the valid random access response message, the UE transmits data including an identifier of the UE or the like to the base station through a Physical Uplink Shared Channel (PUSCH) indicated by the UL grant transmitted through the PDCCH from the base station (S105). Next, the UE waits for reception of PDCCH as an indication of the base station for collision resolution. If the UE successfully receives the PDCCH through the identifier of the UE (S106), the random access procedure is terminated.

After the above procedure, the UE receives a PDCCH/PDSCH (S107) and transmits a Physical Uplink Shared Channel (PUSCH)/Physical Uplink Control Channel (PUCCH) (S108) as a general UL/DL signal transmission procedure. In particular, the UE may receive Downlink Control Information (DCI) through the PDCCH. The DCI may include control information such as resource allocation information for the UE. In addition, the format of DCI may vary according to the intended use. Uplink Control Information (UCI) transmitted by a UE to a base station through UL includes DL/UL ACK/NACK signals, channel Quality Indicators (CQIs), precoding Matrix Indexes (PMIs), rank Indicators (RI), and the like. Here, CQI, PMI, and RI may be included in Channel State Information (CSI). In the 3GPP NR system, the UE can transmit control information such as the HARQ-ACK and CSI described above through the PUSCH and/or the PUCCH.

Fig. 4A and 4B illustrate SS/PBCH blocks for initial cell access in a 3GPP NR system.

When power is turned on or a new cell is desired to be accessed, the UE may acquire time and frequency synchronization with the cell and perform an initial cell search procedure. The UE may detect cells during a cell search procedurePhysical cell identity N of (2) ^cell _ID . To this end, the UE may receive synchronization signals, e.g., a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS), from the base station and synchronize with the base station. In this case, the UE can obtain information such as a cell Identification (ID).

Referring to fig. 4a, the Synchronization Signal (SS) will be described in more detail. The synchronization signals can be classified into PSS and SSS. The PSS may be used to obtain time domain synchronization and/or frequency domain synchronization, such as OFDM symbol synchronization and slot synchronization. SSS can be used to obtain frame synchronization and cell group ID. Referring to fig. 4a and table 2, the ss/PBCH block can be configured with 20 RBs (=240 subcarriers) in succession on a frequency axis and can be configured with 4 OFDM symbols in succession on a time axis. In this case, in the SS/PBCH block, PSS is transmitted in the first OFDM symbol and SSs is transmitted in the third OFDM symbol through 56 th to 182 th subcarriers. Here, the lowest subcarrier index of the SS/PBCH block is numbered from 0. In the first OFDM symbol in which the PSS is transmitted, the base station transmits no signal through the remaining subcarriers, i.e., the 0 th to 55 th subcarriers and the 183 th to 239 th subcarriers. Further, in the third OFDM symbol in which SSS is transmitted, the base station does not transmit signals through 48 th to 55 th subcarriers and 183 th to 191 th subcarriers. The base station transmits a Physical Broadcast Channel (PBCH) through the remaining REs in the SS/PBCH block except for the above signals.

TABLE 2

The SS allows a total of 1008 unique physical layer cell IDs to be grouped into 336 physical layer cell identifier groups by a combination of three PSS and SSs, each group comprising three unique identifiers, in particular such that each physical layer cell ID will be only part of one physical layer cell identifier group. Thus, physical layer cell ID N ^cell _ID ＝3N ⁽¹⁾ _ID +N ⁽²⁾ _ID Can be defined by an index N ranging from 0 to 335 indicating the physical layer cell identifier group ⁽¹⁾ _ID And indicating physical layerIndex N of physical layer identifiers ranging from 0 to 2 in a cell identifier group ⁽²⁾ _ID Uniquely defined. The UE may detect the PSS and identify one of three unique physical layer identifiers. Further, the UE can detect the SSS and identify one of 336 physical layer cell IDs associated with the physical layer identifier. In this case, sequence d of PSS _PSS (n) is as follows.

d _PSS (n)＝1-2x(m)

0≤n＜127

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

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

furthermore, sequence d of SSS _SSS (n) is as follows.

d _SSS (n)＝[1-2x ₀ ((n+m ₀ )mod 127)I1-2x ₁ ((n+m ₁ )mod 127)]

0≤n＜127

Here the number of the elements is the number,and is also provided with

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

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

A radio frame having a length of 10ms may be divided into two half frames having a length of 5 ms. Referring to fig. 4B, a slot in which an SS/PBCH block is transmitted in each field will be described. The time slot in which the SS/PBCH block is transmitted may be either of cases A, B, C, D and E. In case a, the subcarrier spacing is 15kHz and the starting point in time of the SS/PBCH block is the (2, 8 +14 x n) th symbol. In this case, n=0 or 1 at a carrier frequency of 3GHz or less. Further, at carrier frequencies above 3GHz and below 6GHz, n=0, 1, 2, 3 may be possible. In case B, the subcarrier spacing is 30kHz and the starting time point of the SS/PBCH block is {4,8, 16, 20} +28 x n. In this case, n=0 at a carrier frequency of 3GHz or less. Further, n=0, 1 may be possible at carrier frequencies above 3GHz and below 6 GHz. In case C, the subcarrier spacing is 30kHz and the starting point in time of the SS/PBCH block is the (2, 8 +14 x n) th symbol. In this case, n=0 or 1 at a carrier frequency of 3GHz or less. Further, at carrier frequencies above 3GHz and below 6GHz, n=0, 1, 2, 3 may be possible. In case D, the subcarrier spacing is 120kHz and the starting point in time of the SS/PBCH block is the (4, 8, 16, 20} +28 x n) th symbol. In this case, n=0, 1, 2, 3, 5, 6, 7, 8, 10, 11, 12, 13, 15, 16, 17, 18 at a carrier frequency of 6GHz or higher. In case E, the subcarrier spacing is 240kHz and the starting point in time of the SS/PBCH block is the ({ 8, 12, 16, 20, 32, 36, 40, 44} +56 x n) th symbol. In this case, n=0, 1, 2, 3, 5, 6, 7, 8 at a carrier frequency of 6GHz or higher.

Fig. 5 illustrates a procedure of transmitting control information and a control channel in a 3GPP NR system. Referring to fig. 5A, the base station may add a Cyclic Redundancy Check (CRC) masked (e.g., exclusive or operation) with a Radio Network Temporary Identifier (RNTI) to control information (e.g., downlink Control Information (DCI)) (S202). The base station may scramble the CRC with an RNTI value determined according to the purpose/destination of each control information. The common RNTI used by the one or more UEs can include at least one of a system information RNTI (SI-RNTI), a paging RNTI (P-RNTI), a random access RNTI (RA-RNTI), and a transmit power control RNTI (TPC-RNTI). Further, the UE-specific RNTI may include at least one of a cell temporary RNTI (C-RNTI) and a CS-RNTI. Thereafter, the base station may perform rate matching according to the amount of resources for PDCCH transmission (S206) after performing channel coding (e.g., polarity coding) (S204). Thereafter, the base station may multiplex DCI based on a PDCCH structure based on Control Channel Elements (CCEs) (S208). Further, the base station may apply additional procedures such as scrambling, modulation (e.g., QPSK), interleaving, etc. to the multiplexed DCI (S210), and then map the DCI to the resources to be transmitted. A CCE is a basic resource element for PDCCH, and one CCE may include a plurality of (e.g., six) Resource Element Groups (REGs). One REG may be configured with multiple (e.g., 12) REs. The number of CCEs for one PDCCH may be defined as an aggregation level. In a 3GPP NR system, an aggregation level of 1, 2, 4, 8, or 16 can be used. Fig. 5B is a diagram related to multiplexing of CCE aggregation levels and PDCCHs, and illustrates types of CCE aggregation levels for one PDCCH and CCEs transmitted in a control region according thereto.

CORESET is a time-frequency resource in which a PDCCH (i.e., a control signal for a UE) is transmitted. Furthermore, a search space to be described later may be mapped to one CORESET. Thus, the UE may monitor the time-frequency domain designated as CORESET instead of monitoring all frequency bands for PDCCH reception and decode the PDCCH mapped to CORESET. The base station may configure one or more CORESETs for each cell to the UE. CORESET may be configured with up to three consecutive symbols on the time axis. Further, CORESET may be configured in units of six consecutive PRBs on the frequency axis. In the embodiment of fig. 5, CORESET #1 is configured with contiguous PRBs, while CORESET #2 and CORESET #3 are configured with non-contiguous PRBs. CORESET can be located in any symbol in a slot. For example, in the embodiment of FIG. 5, CORESET#1 starts with the first symbol of the slot, CORESET#2 starts with the fifth symbol of the slot, and CORESET#9 starts with the ninth symbol of the slot.

Fig. 7 illustrates a method for setting a PUCCH search space in a 3GPP NR system.

For transmitting the PDCCH to the UE, each CORESET may have at least one search space. In embodiments of the present disclosure, the search space is a set of all time-frequency resources (hereinafter PDCCH candidates) that can be used to transmit the PDCCH of the UE. The search space may include a common search space that requires UEs of the 3GPP NR to search together and a terminal-specific search space or a UE-specific search space that requires a specific UE to search. In the common search space, UEs may monitor PDCCHs set such that all UEs in a cell belonging to the same base station search in common. Furthermore, a UE-specific search space may be set for each UE such that the UE monitors PDCCHs allocated to each UE at search space positions different according to the UE. In the case of UE-specific search spaces, the search spaces between UEs may be partially overlapped and allocated due to a limited control region in which PDCCHs may be allocated. Monitoring the PDCCH includes blind decoding the PDCCH candidates in the search space. When blind decoding is successful, it may be expressed as (successfully) detecting/receiving a PDCCH, and when blind decoding is failed, it may be expressed as not detecting/not receiving or not successfully detecting/receiving a PDCCH.

For convenience of explanation, a PDCCH scrambled with a Group Common (GC) RNTI previously known to one or more UEs in order to transmit DL control information to the one or more UEs is referred to as a Group Common (GC) PDCCH or a common PDCCH. In addition, a PDCCH scrambled with an RNTI of a specific terminal that the specific UE already knows in order to transmit UL scheduling information or DL scheduling information to the specific UE is referred to as a PDCCH of the specific UE. The common PDCCH may be included in the common search space, and the UE-specific PDCCH may be included in the common search space or the UE-specific PDCCH.

The base station may signal information about resource allocation of a Paging Channel (PCH) and a downlink shared channel (DL-SCH) as transport channels (i.e., DL grant) or information about resource allocation of an uplink shared channel (UL-SCH) and a hybrid automatic repeat request (HARQ) (i.e., UL grant) to each UE or UE group through the PDCCH. The base station may transmit the PCH transport block and the DL-SCH transport block through the PDSCH. The base station may transmit data excluding specific control information or specific service data through the PDSCH. In addition, the UE may receive data excluding specific control information or specific service data through the PDSCH.

The base station may include information on to which UE(s) PDSCH data is transmitted and how the PDSCH data is to be received and decoded by the corresponding UE in the PDCCH, and transmit the PDCCH. For example, assume that DCI transmitted on a specific PDCCH is CRC-masked with RNTI "a" and the DCI indicates that PDSCH is allocated to radio resource "B" (e.g., frequency location) and indicates transport format information "C" (e.g., transport block size, modulation scheme, coding information, etc.). The UE monitors the PDCCH using RNTI information possessed by the UE. In this case, if there is a UE performing blind decoding of the PDCCH using the "a" RNTI, the UE receives the PDCCH and receives PDSCH indicated by "B" and "C" through information of the received PDCCH.

Table 3 shows an embodiment of a Physical Uplink Control Channel (PUCCH) used in a wireless communication system.

TABLE 3

PUCCH format	Length of 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

The PUCCH may be used to transmit the following UL Control Information (UCI).

-a Scheduling Request (SR): information for requesting UL-SCH resources.

-HARQ-ACK: a response to PDCCH (indicating DL SPS release) and/or a response to DL Transport Block (TB) on PDSCH. The HARQ-ACK indicates whether information transmitted on the PDCCH or PDSCH is received. The HARQ-ACK response includes a positive ACK (abbreviated ACK), a negative ACK (hereinafter NACK), discontinuous Transmission (DTX), or NACK/DTX. Here, the term HARQ-ACK is used in combination with HARQ-ACK/NACK and ACK/NACK. Generally, an ACK may be represented by a bit value of 1, while a NACK may be represented by a bit value of 0.

-Channel State Information (CSI): feedback information about DL channels. The UE generates it based on CSI-Reference Signals (RSs) transmitted by the base station. Multiple Input Multiple Output (MIMO) -related feedback information includes a Rank Indicator (RI) and a Precoding Matrix Indicator (PMI). The CSI can be divided into CSI part 1 and CSI part 2 according to information indicated by the CSI.

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

PUCCH format 0 is a format capable of delivering 1-bit or 2-bit HARQ-ACK information or SR. PUCCH format 0 can be transmitted through one or two OFDM symbols on the time axis and one PRB on the frequency axis. When in two OFDM symbolsWhen PUCCH format 0 is transmitted in the number, the same sequence on two symbols may be transmitted through different RBs. At this time, the sequence may be a sequence cyclically shifted from the base sequence used in PUCCH format 0. Through this, the UE can obtain a frequency diversity gain. In more detail, the UE may be based on M _bit Bits UCI (M) _bit =1 or 2) to determine a Cyclic Shift (CS) value m _cs . In addition, the value m can be determined by _cs Is mapped to 12 REs of 1 OFDM symbol and 1 PRB to transmit a base sequence of length 12. When the number of cyclic shifts available to the UE is 12 and M _bit When=1, 1-bit UCI 0 and 1 may be represented by two cyclic shift sequences having cyclic shift values differing by 6, respectively. In addition, when M _bit When=2, 2 bits UCI 00, 01, 11, and 10 can be represented by four cyclic shift sequences having cyclic shift values differing by 3, respectively.

PUCCH format 1 may deliver 1-bit or 2-bit HARQ-ACK information or SRs. PUCCH format 1 may be transmitted through consecutive OFDM symbols on the time axis and one PRB on the frequency axis. Here, the number of OFDM symbols occupied by PUCCH format 1 may be one of 4 to 14. More specifically, can be applied to M _bit UCI of=1 is BPSK modulated. The UE may utilize Quadrature Phase Shift Keying (QPSK) for M _bit UCI of=2. The signal is obtained by multiplying the modulated complex-valued symbol d (0) by a sequence of length 12. In this case, the sequence may be a base sequence for PUCCH format 0. The UE expands the even-numbered OFDM symbols to which PUCCH format 1 is allocated by a time axis Orthogonal Cover Code (OCC) to transmit the obtained signal. PUCCH format 1 determines the maximum number of different UEs multiplexed in one RB according to the length of OCC to be used. Demodulation reference signals (DMRS) may be extended with OCC and mapped to odd-numbered OFDM symbols of PUCCH format 1.

PUCCH format 2 may deliver UCI of more than 2 bits. PUCCH format 2 may be transmitted through one or two OFDM symbols on the time axis and one or more RBs on the frequency axis. When PUCCH format 2 is transmitted in two OFDM symbols, different RBs are transmitted through two OFDM symbolsThe transmitted sequences may be identical to each other. Here, the sequence is formed by a plurality of modulated complex symbols d (0), a.d., d (M _symbol -1). Here, M _symbol May be M _bit /2. Through this, the UE can obtain a frequency diversity gain. More specifically, for M _bit UCI (M) _bit 2) bit-level scrambling, QPSK modulation, and mapping it to RBs of one or two OFDM symbols. Here, the number of RBs may be one of 1 to 16.

PUCCH format 3 or PUCCH format 4 may deliver UCI of more than 2 bits. PUCCH format 3 or PUCCH format 4 may be transmitted through consecutive OFDM symbols on the time axis and one PRB on the frequency axis. The number of OFDM symbols occupied by PUCCH format 3 or PUCCH format 4 may be one of 4 to 14. Specifically, the UE utilizes-Binary Phase Shift Keying (BPSK) or QPSK versus M _bit UCI (M) _bit >2) Modulated to generate complex-valued symbols d (0) to d (M _symb -1). Here, when pi/2-BPSK is used, M _symb ＝M _bit And when QPSK is used, M _symb ＝M _bit /2. The UE may not apply block unit extension to PUCCH format 3. However, the UE may apply block unit spreading to one RB (i.e., 12 subcarriers) using a pre dft-OCC of length 12, so that PUCCH format 4 may have two or four multiplexing capabilities. The UE performs transmit precoding (or DFT precoding) on the spread signal and maps it to each RE to transmit the spread signal.

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

PUCCH format 1, PUCCH format 3, or PUCCH format 4 may be configured by an RRC signal to indicate frequency hopping in a slot. When frequency hopping is configured, an index of RBs to be frequency hopped can be configured with an RRC signal. When PUCCH format 1, PUCCH format 3, or PUCCH format 4 is transmitted through N OFDM symbols of the time axis, the first hop may have floor (N/2) OFDM symbols and the second hop may have ceiling (N/2) OFDM symbols.

PUCCH format 1, PUCCH format 3, or PUCCH format 4 may be configured to be repeatedly transmitted in a plurality of slots. In this case, the number K of slots in which the PUCCH is repeatedly transmitted may be configured by an RRC signal. The repeatedly transmitted PUCCH must start with an OFDM symbol at a constant position in each slot and have a constant length. When one OFDM symbol among OFDM symbols of a slot in which the UE should transmit the PUCCH is indicated as a DL symbol through an RRC signal, the UE may not transmit the PUCCH in the corresponding slot and delay transmission of the PUCCH to the next slot to transmit the PUCCH.

Meanwhile, in the 3GPP NR system, the UE may perform transmission/reception using a bandwidth equal to or less than that of a carrier (or cell). To this end, the UE may receive a bandwidth portion (BWP) configured with a continuous bandwidth of some of the carrier bandwidths. A UE operating according to TDD or in unpaired spectrum can receive up to four DL/UL BWP pairs in one carrier (or cell). In addition, the UE may activate one DL/UL BWP pair. A UE operating according to FDD or operating in a paired spectrum can receive up to four DL BWP on DL carriers (or cells) and up to four UL BWP on UL carriers (or cells). The UE may activate one DL BWP and one UL BWP for each carrier (or cell). The UE may not perform reception or transmission in time-frequency resources other than the activated BWP. The activated BWP may be referred to as an active BWP.

The base station may indicate an activated BWP among BWPs configured by the UE through Downlink Control Information (DCI). BWP indicated by DCI is activated and BWP of other configuration is deactivated. In a carrier (or cell) operating in TDD, a base station may include a Bandwidth Part Indicator (BPI) indicating BWP to be activated to change a DL/UL BWP pair of a UE in DCI for scheduling PDSCH or PUSCH. The UE may receive DCI for scheduling PDSCH or PUSCH and may identify DL/UL BWP pairs activated based on BPI. For DL carriers (or cells) operating in FDD, the base station may include BPI indicating BWP to be activated in DCI for scheduling PDSCH in order to change DL BWP of the UE. For UL carriers (or cells) operating in FDD, the base station may include a BPI indicating BWP to be activated in DCI for scheduling PUSCH in order to change UL BWP of the UE.

Fig. 8 is a conceptual diagram illustrating carrier aggregation.

Carrier aggregation is a method in which a UE uses a plurality of frequency blocks or (in a logical sense) cells configured with UL resources (or component carriers) and/or DL resources (or component carriers) as one large logical band in order for a wireless communication system to use a wider frequency band. One component carrier may also be referred to as a term called primary cell (PCell) or secondary cell (SCell) or primary SCell (PScell). Hereinafter, however, for convenience of description, the term "component carrier" is used.

Referring to fig. 8, as an example of the 3GPP NR system, the entire system band may include at most 16 component carriers, and each component carrier may have a bandwidth of at most 400 MHz. The component carriers may include one or more physically contiguous subcarriers. Although each component carrier is shown in fig. 8 as having the same bandwidth, this is merely an example, and each component carrier may have a different bandwidth. In addition, although each component carrier is shown as being adjacent to each other on the frequency axis, the drawing is logically shown, and each component carrier may be physically adjacent to each other or may be spaced apart.

A different center frequency may be used for each component carrier. In addition, one common center frequency may be used in physically adjacent component carriers. Assuming that all component carriers are physically adjacent in the embodiment of fig. 8, the center frequency a may be used in all component carriers. In addition, the center frequency a and the center frequency B can be used in each component carrier, assuming that the respective component carriers are not physically adjacent to each other.

When it is openWhen the total system band is extended by the overload wave aggregation, a band for communication with each UE can be defined in units of component carriers. UE a may use 100MHz as a total system band and perform communication using all five component carriers. UE B ₁ ～B ₅ Communication can be performed using only a 20MHz bandwidth and using one component carrier. UE C ₁ And C ₂ Communication may be performed using a 40MHz bandwidth and using two component carriers, respectively. The two component carriers may or may not be logically/physically contiguous. UE C ₁ Indicating the use of two non-adjacent component carriers, while UE C ₂ A case where two adjacent component carriers are used is shown.

Fig. 9 is a diagram for explaining signal carrier communication and multicarrier communication. In particular, fig. 9 (a) shows a single carrier subframe structure and fig. 9 (b) shows a multi-carrier subframe structure.

Referring to fig. 9 (a), in the FDD mode, a general wireless communication system may perform data transmission or reception through one DL frequency band and one UL frequency band corresponding thereto. In another particular embodiment, in TDD mode, the wireless communication system may divide a radio frame into UL time units and DL time units in the time domain and perform data transmission or reception through the UL/DL time units. Referring to fig. 9 (b), three 20MHz Component Carriers (CCs) can be aggregated into each of UL and DL so that a bandwidth of 60MHz can be supported. Each CC may or may not be adjacent to each other in the frequency domain. Fig. 9 (b) shows a case where the bandwidth of the UL CC and the bandwidth of the DL CC are the same and symmetrical, but the bandwidth of each CC can be independently determined. Furthermore, asymmetric carrier aggregation with different numbers of UL CCs and DL CCs is possible. DL/UL CCs allocated/configured to a specific UE through RRC may be referred to as serving DL/UL CCs of the specific UE.

The base station may perform communication with the UE by activating some or all of the serving CCs of the UE or disabling some CCs. The base station can change CCs to be activated/deactivated and 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 will not be deactivated unless the CC allocation for the UE is completely reconfigured or the UE is switched. One CC that is not deactivated by the UE is referred to as a primary CC (PCC) or primary cell (PCell), and a CC that the base station can freely activate/deactivate is referred to as a secondary CC (SCC) or secondary cell (SCell).

Meanwhile, 3GPP NR manages radio resources using the concept of a cell. A cell is defined as a combination of DL resources and UL resources, i.e., a combination of DL CCs and UL CCs. A cell may be configured with DL resources alone or may be configured with a combination of DL and UL resources. When carrier aggregation is supported, a link between a carrier frequency of a DL resource (or DL CC) and a carrier frequency of a UL resource (or UL CC) may be indicated by system information. The carrier frequency refers to the center frequency of each cell or CC. The cell corresponding to the PCC is referred to as PCell, and the cell corresponding to the SCC is referred to as SCell. The carrier corresponding to the PCell in DL is DL PCC and the carrier corresponding to the PCell in UL is UL PCC. Similarly, the carrier in DL corresponding to SCell is DL SCC, and the carrier in UL corresponding to SCell is UL SCC. Depending on the UE capabilities, the serving cell may be configured with one PCell and zero or more scells. In the case of a UE in the rrc_connected state but not configured for carrier aggregation or not supporting carrier aggregation, only one serving cell is configured with only PCell.

As described above, the term "cell" used in carrier aggregation is distinguished from the term "cell" which refers to a certain geographical area where communication services are provided through one base station or one antenna group. That is, one component carrier may also be referred to as a scheduling cell, a scheduled cell, a primary cell (PCell), a secondary cell (SCell), or a primary SCell (PScell). However, in order to distinguish between a cell representing a certain geographical area and a carrier aggregated cell, in the present disclosure, the carrier aggregated cell is referred to as a CC, and the cell of the geographical area is referred to as a cell.

Fig. 10 is a diagram showing an example in which a cross-carrier scheduling technique is applied. When the cross-carrier scheduling is set, a control channel transmitted through the first CC may schedule a data channel transmitted through the first CC or the second CC using a Carrier Indicator Field (CIF). CIF is included in DCI. In other words, a scheduling cell is set, and DL grant/UL grant transmitted in the PDCCH region of the scheduling cell schedules PDSCH/PUSCH of the cell to be scheduled. That is, there is a search region for a plurality of component carriers in the PDCCH region of the scheduling cell. The PCell may basically be a scheduling cell, and a specific SCell may be designated as a scheduling cell by an upper layer.

In the embodiment of fig. 10, it is assumed that three DL CCs are combined. Here, it is assumed that DL component carrier #0 is DL PCC (or PCell), and DL component carrier #1 and DL component carrier #2 are DL SCCs (or scells). Further, it is assumed that DL PCC is set as PDCCH monitoring CC. When cross-carrier scheduling is not configured by UE-specific (or UE group-specific or cell-specific) higher layer signaling, CIF is disabled and each DL CC can transmit only PDCCH for scheduling its PDSCH without CIF according to NR PDCCH rules (non-cross-carrier scheduling, self-carrier scheduling). Meanwhile, if cross-carrier scheduling is configured through UE-specific (or UE group-specific or cell-specific) higher layer signaling, CIF is enabled, and a specific CC (e.g., DL PCC) may use CIF to transmit not only PDCCH for scheduling PDSCH of DL CC a but also PDCCH for scheduling PDSCH of another CC (cross-carrier scheduling). On the other hand, the PDCCH is not transmitted in another DL CC. Accordingly, the UE monitors a PDCCH including no CIF to receive a PDSCH from the carrier scheduling according to whether the UE is configured with the cross-carrier scheduling, or monitors a PDCCH including CIF to receive a PDSCH of the cross-carrier scheduling.

On the other hand, fig. 9 and 10 illustrate subframe structures of the 3GPP LTE-a system, and the same or similar configuration may be applied to the 3GPP NR system. However, in the 3GPP NR system, the subframes of fig. 9 and 10 may be replaced with slots.

Referring to fig. 11 and 12, a method of receiving a PDCCH/PDSCH by a user equipment and a method of transmitting a PUCCH/PUSCH by the user equipment will be described.

The user equipment can receive the DCI format through the PDCCH. The DCI format includes the following information.

DCI format 0_x (x=0, 1, 2): DCI format for scheduling PUSCH transmission (hereinafter, DL Grant (DG) DCI format or DG DCI)

DCI format 1_x (x=0, 1, 2): DCI format for scheduling PDSCH reception (hereinafter, UL Grant (UG) DCI format or UG DCI)

When the user equipment receives a DCI format for scheduling PDSCH (i.e., DG DCI format), the user equipment can receive PDSCH scheduled by DG DCI format. To this end, the user equipment can interpret (determine) from the DG DCI format i) the slot in which the PDSCH is scheduled and ii) the starting index/length of the symbols within the slot. The Time Domain Resource Allocation (TDRA) field in the DG DCI format can indicate (i) a K0 value, which is timing information of a slot (e.g., slot offset), and (ii) a Start Length Indicator Value (SLIV), which is an index/length of a start symbol within the slot. Here, the K0 value can be a non-negative integer value. The SLIV can be a value obtained by jointly encoding the index S of the start symbol within the slot and the length L value. Further, the SLIV can be a value in which an index S/length L value of a start symbol within a slot is separately transmitted. For example, in the case of a normal CP, S can have 1 of values 0,1,..13, and L can have a value that satisfies one of natural numbers for the condition that s+l is less than or equal to 14. In the case of the extended CP, S may have 1 of values 0,1, …, 11, and L may have a value satisfying one of natural numbers of the condition that s+l is less than or equal to 12.

The user equipment can determine a slot in which the PDSCH is received based on the K0 value. Specifically, based on (i) the K0 value, (ii) the index of the slot in which the DG DCI is received, (iii) the SCS of the (DL) BWP in which the DG DCI is received (i.e., the SCS applied to the DG DCI) and (iv) the SCS of the (DL) BWP in which the PDSCH is received (i.e., the SCS applied to the PDSCH), the slot in which the PDSCH is received can be determined.

As an example, it is assumed that (i) SCS of BWP in which DG DCI is received and (ii) SCS of BWP in which PDSCH is received are the same. In this case, it is assumed that DG DCI is received in DL slot n. In this case, the PDSCH corresponding to the DG DCI is received in the DL slot n+k0.

As another example, it is assumed that SCS of BWP in which DG DCI is received is 15khz x 2 mu_pdcch and SCS of BWP in which PDSCH is received is 15khz x 2 mu_pdsch. In this case, it is assumed that DG DCI is received in DL slot n. Here, the index of DL slot n is an index of SCS according to BWP in which DG DCI is received. In this case, PDSCH corresponding to DG DCI is received in DL slot floor (n×2 μm_pdsch/2 μm_pdcch) +k0. Here, the index of DL slot floor (n×2 μm_pdsch/2 μm_pdcch) +k0 is an index of SCS according to BWP in which PDSCH is received. mu_pdcch and mu_pdsch can have values of 0, 1, 2, and 3, respectively.

Referring to fig. 11, it is assumed that the user equipment has received a PDCCH scheduling a PDSCH in DL slot n. Further, it is assumed that DCI delivered through PDCCH indicates k0=3. Further, it is assumed that (i) an SCS of a DL BWP in which a PDCCH is received (i.e., an SCS applied to the PDCCH; PDCCH SCS) is identical to (ii) an SCS of a DL BWP in which a PDSCH is scheduled (i.e., an SCS applied to the PDSCH; PDSCH SCS). In this case, the user equipment can determine to schedule PDSCH in DL slot n+k0 (i.e., slot n+3).

The user equipment can determine a symbol to which the PDSCH is allocated using an index S of a starting symbol and a length L value in a slot determined based on the K0 value. The symbols to which the PDSCH is allocated are symbols S to s+l-1 in the slot determined based on the K0 value. Here, the symbols S to s+l-1 are L consecutive symbols.

For the user equipment, DL slot aggregation can be additionally configured from the base station. The DL slot aggregation value can be 2, 4 or 8. If DL slot aggregation is configured, the user equipment can receive PDSCH in consecutive slots corresponding to the slot aggregation value starting from a slot determined based on the K0 value.

When the user equipment receives a DCI format (e.g., DG DCI format) for scheduling PUCCH, the user equipment can transmit the scheduled PUCCH. Here, the PUCCH can include HARQ-ACK information. The PDSCH-to-harq_feedback timing indicator field included in the DG DCI format can indicate a K1 value for information on a slot in which the PUCCH is scheduled. Here, the K1 value can be a non-negative integer value. The K1 value of DCI format 1_0 can indicate one value in {0,1,2,3,4,5,6,7} (hereinafter, referred to as K1-set). The K1 values of DCI formats 1_1 to 1_2 can indicate one value among K1 values (i.e., K1-sets) configured/set by a higher layer (e.g., RRC).

The HARQ-ACK information may be 2 types of HARQ-ACK information regarding whether the reception of the channel is successful. In the first type, when PDSCH is scheduled through the DCI format 1_x, HARQ-ACK information can be HARQ-ACK as to whether reception of PDSCH is successful. In the second type, when the DCI format 1_x is DCI indicating release of the SPS PDSCH, the HARQ-ACK information can be HARQ-ACK as to whether reception of the DCI formats 1_0, 1_1 to 1_2 is successful.

The user equipment can determine a slot in which a first type of PUCCH including HARQ-ACK information is transmitted as follows. The user equipment can determine a (UL) slot #a overlapping with a last symbol of the PDSCH corresponding to the HARQ-ACK information. When the index of (UL) slot #a is m, the index of (UL) slot #b in which the user equipment transmits the PUCCH including HARQ-ACK information can be m+k1. Here, the index of the (UL) slot is a value according to SCS of UL BWP in which the PUCCH is transmitted (i.e., SCS applied to PUCCH; SCS of PUCCH). Meanwhile, when the user equipment is configured with DL slot aggregation, the last symbol of the PDSCH indicates the last symbol of the PDSCH scheduled in the last slot among slots in which the PDSCH is received.

Referring to fig. 12, it is assumed that the user equipment has received a PDCCH scheduling a PDSCH in DL slot n. Further, it is assumed that DCI in PDCCH indicates k0=3 and k1=2. Further, it is assumed that SCS of DL BWP in which PDCCH is received (i.e., SCS of PDCCH), SCS of DL BWP in which PDSCH is scheduled (i.e., SCS of PDSCH), and SCS of UL BWP in which PUCCH is transmitted (i.e., SCS of PUCCH) are the same. In this case, the user equipment can determine to schedule PDSCH in DL slot n+k0, i.e., slot n+3. Further, the user equipment can determine an UL slot overlapping with the last symbol of the PDSCH scheduled in DL slot n+3. Here, the last symbol of PDSCH of DL slot n+3 overlaps with UL slot n+3. Thus, the user equipment can transmit PUCCH in UL slot n+3+k1, i.e., slot n+5.

The user equipment can determine a slot in which a second type of PUCCH including HARQ-ACK information is transmitted as follows. The user equipment can determine UL slot #a overlapping with an end symbol of a PDCCH (e.g., PDCCH delivering SPS release DCI) corresponding to HARQ-ACK information. When the index of UL slot #a is m, the index of UL slot #b in which the user equipment transmits the PUCCH including HARQ-ACK information may be m+k1. Here, the index of the UL slot is a value according to SCS of UL BWP in which the PUCCH is transmitted (i.e., SCS of PUCCH).

Referring to fig. 13, it is assumed that the user equipment has received a PDCCH delivering SPS PDSCH release DCI in DL slot n. Suppose that DCI delivered from PDCCH indicates k1=3. Further, it is assumed that SCS of DL BWP in which PDCCH is received is the same as SCS of UL BWP in which PUCCH is transmitted. In this case, the user equipment can determine UL slot n overlapping with the last symbol of the PDCCH of DL slot n. In this case, the user equipment can determine that PUCCH delivering HARQ-ACK for SPS PDSCH release DCI is scheduled in UL slot n+k1, i.e., UL slot n+3.

When the user equipment receives a DCI format (i.e., UG DCI format) for scheduling PUSCH, the user equipment can transmit the scheduled PUSCH. For this, the user equipment should interpret (determine) from the DCI (i) the slot in which the PUSCH is scheduled and (ii) the starting index and length of the symbols within the slot. The TDRA field of the UG DCI format can indicate (i) a K2 value for information about scheduling a slot, and (ii) a SLIV, which is a value of information about an index and a length of a start symbol within the slot. Here, the K2 value can be a non-negative integer value. Here, the SLIV can be a value obtained by jointly encoding the index S of the start symbol within the slot and the length L value. Further, the SLIV can be a value in which the index S and the length L value of the start symbol within the slot are separately transmitted. For example, in the case of a normal CP, S can have 1 of values 0, 1,..13, and L can have a value that satisfies one of natural numbers for the condition that s+l is less than or equal to 14. In the case of the extended CP, S can have 1 of the values 0, 1, …, 11, and L can have a value that satisfies one of natural numbers of the condition that s+l is less than or equal to 12.

The user equipment can determine a slot in which to schedule PUSCH based on the K2 value. Specifically, the user equipment can determine a slot in which PUSCH should be transmitted based on a K2 value, a slot index in which UG DCI is received, SCS of DL BWP in which UG DCI is received, or SCS of UL BWP in which PUSCH is transmitted.

As an example, it is assumed that (i) DL BWP in which UG DCI is received and (ii) SCS of UL BWP in which PUSCH is transmitted are the same. Further, it is assumed that UG DCI is received in DL slot n. In this case, PUSCH can be transmitted in UL slot n+k2.

As another example, it is assumed that SCS of DL BWP in which UG DCI is received is 15khz x 2 μm_pdcch and SCS of UL BWP in which PUSCH is transmitted is 15khz x 2 μm_pusch. Further, it is assumed that UG DCI is received in DL slot n. Here, the index of the DL slot n is an index according to SCS of DL BWP in which UG DCI is received (i.e., SCS of UG DCI). In this case, PUSCH can be transmitted in slot floor (n×2 μm_pusch/2 μm_pdcch) +k2. Here, the slot index floor (n×2 μm_pusch/2 μm_pdcch) +k2 is an index of SCS according to UL BWP in which PUSCH is transmitted. In the above description, mu_pdcch to mu_pusch can have values of 0, 1, 2, and 3.

Referring to fig. 13, it is assumed that the user equipment has received a PDCCH scheduling PUSCH in DL slot n. Further, it is assumed that DCI delivered through PDCCH indicates k2=3. Further, it is assumed that SCS of DL BWP in which PDCCH is received is the same as SCS of UL BWP in which PUCCH is transmitted. In this case, the user equipment can determine to schedule PUSCH in UL slot n+k2=n+3.

The user equipment can determine a symbol to which the PUSCH is allocated using the index S of the starting symbol in the slot determined based on the K2 value and the length L value. The symbols to which the PUSCH is allocated are symbols S to s+l-1 in the slot determined based on the K2 value. Here, the symbols S to s+l-1 are L consecutive symbols.

For user equipment, UL slot aggregation can be additionally configured from the base station. The UL slot aggregation value can be 2, 4 or 8. If UL slot aggregation is configured, the user equipment can transmit PDSCH in consecutive slots corresponding to the slot aggregation value starting from the slot determined based on the K2 value.

In fig. 11 to 13, the user equipment uses K0 value, K1 value, and K2 value in order to determine a slot in which the PDSCH is received, a slot in which the PUCCH is transmitted, and a slot in which the PUSCH is transmitted. For convenience, a slot obtained by assuming that K0, K1 and K2 are all 0 is referred to as a reference point or a reference slot.

In fig. 11, the reference slot to which the K0 value is applied is a DL slot n in which the PDCCH is received.

In fig. 12, the reference slot to which the K1 value is applied is an UL slot overlapping with the last symbol of the PDSCH, i.e., UL slot n+3.

In fig. 13, the reference slot to which the K1 value is applied is an UL slot overlapping with the last symbol of the PDCCH, i.e., UL slot n. Furthermore, the reference slot to which the K2 value is applied is UL slot n.

For convenience, in the following description, it is assumed that SCS of DL BWP in which PDSCH/PDCCH is received is the same as SCS of UL BWP in which PUSCH/PUCCH is transmitted. Further, UL slots and DL slots are not separately distinguished and are denoted as slots.

In the previous description, the user equipment receives 1 DCI and receives PDSCH or transmits PUSCH in 1 slot based on the DCI. However, when scheduling information for 1 slot is provided (only) through 1 DCI, in order to schedule a plurality of slots, the same number of DCIs as the number of slots should be transmitted. Therefore, waste of DL resources may occur.

To solve this problem, a method can be used in which a user equipment receives 1 DCI from a base station and receives PDSCH in a plurality of slots based on the DCI. Here, the PDSCH received in each slot may include different DL data (e.g., DL-SCH data). More specifically, the PDSCH received in each slot can include a different Transport Block (TB). Further, the PDSCH received in each slot can have a different HARQ process number. In addition, the PDSCH received in each slot can occupy different symbols within each slot.

Further, a method can be used in which the user equipment receives 1 DCI from the base station and transmits PUSCH in a plurality of slots based on the DCI. Here, the PUSCH transmitted in each slot can include different UL data (e.g., UL-SCH data). More specifically, the PUSCH transmitted in each slot can include different TBs. Further, the PUSCH transmitted in each slot can have a different HARQ process number. In addition, the PUSCH transmitted in each slot can occupy different symbols within each slot.

As described above, for convenience, receiving PDSCH or transmitting PUSCH in a plurality of slots based on 1 DCI is referred to as multi-slot scheduling.

For reference, the multi-slot scheduling is different from the existing slot aggregation (a method of repeatedly receiving PDSCH or repeatedly transmitting PUSCH in a plurality of slots) in the following aspects.

Existing slot aggregation is a method of repeatedly receiving or transmitting PDSCH or PUSCH with the same TB in a plurality of slots in order to expand coverage and improve reliability. However, multi-slot scheduling is a method of receiving or transmitting PDSCH or PUSCH with different TBs in a plurality of slots in order to reduce PDCCH overhead.

In existing DL slot aggregation, PDSCH including the same TB is received in a plurality of slots, and thus it is determined whether reception of the same TB is successful from PDSCH received in a plurality of slots. Thus, the user equipment transmits HARQ-ACKs for the same 1 TB to the base station. However, in the multi-slot scheduling, since PDSCH received in a plurality of slots includes different TBs, the user equipment should determine whether reception for each TB is successful. Furthermore, the user equipment should transmit HARQ-ACK to the base station for each TB.

Referring to fig. 14 to 16, multi-slot scheduling will be described.

Referring to fig. 14,1 DCI can schedule PDSCH reception in a plurality of slots. In fig. 14, a PDCCH including 1 DCI can be received in a slot n. The TDRA field of 1 DCI can indicate the timing information K0 value and the SLIV value of a scheduled slot, which is the index and length of a start symbol within each slot. More specifically, the first slot in which the PDSCH is transmitted can be determined by the K0 value. PDSCH reception can be scheduled in M consecutive slots starting from the first slot determined by the K0 value. In fig. 14, k0=3 and m=3. Thus, PDSCH reception can be scheduled in slots n+3, n+4, and n+5. The user equipment can receive an index S of the starting symbol and an indication of the number L of consecutive symbols in the slot for PDSCH reception. The (S, L) may be the same or different for each time slot. If (S, L) is different for each slot, an index S of a starting symbol in each slot and the number (L) of consecutive symbols for reception of PDSCH can be indicated, respectively.

As an example, table 4 shows a TDRA table for multi-slot scheduling. The TDRA table can consist of 12 entries and the entries can be indexed from 0 to 11. Here, at least 1 entry can be configured to schedule PDSCH in a plurality of slots. For example, each entry can schedule PDSCH in up to 4 slots. To this end, each entry can be given up to 4 SLIV values and K0 values. Here, the K0 value represents a difference (PDCCH-to-PDSCH slot offset) between a slot in which the PDCCH is received and a slot in which the PDSCH is received. The SLIV represents a start index S of a symbol in which the PDSCH is received in 1 slot and the number L of consecutive symbols. In table 4, PDSCH scheduled in 1 slot may be denoted as (K0, S, L).

If PDSCH can be scheduled in consecutive slots in multi-slot scheduling, the K0 value indicating the scheduled slot in the TDRA table can be omitted. For example, referring to table 5, each entry in the TDRA table can only include 1K 0 value. Also, each entry (or at least 1 entry) in the TDRA table can include 2 or more SLIV values (i.e., (S, L)). In this case, PDSCH reception can be scheduled in a symbol corresponding to a first SLIV value (first (S, L)) in a slot determined according to the K0 value, and PDSCH reception can be scheduled on a symbol corresponding to a second SLIV value (second (S, L)) in a next slot. Specifically, K0 of each entry in the TDRA table can be determined as { K0 } _r ，K0 _r +i，K0 _r +M _r -1}. Here, K0 _r K0 representing the r-th entry, and M _r Corresponding to the number of SLIV values included in the nth entry.

If PDSCH can be scheduled in discontinuous slots in multi-slot scheduling, the TDRA table can include (i) a K0 value and (ii) an offset (O) value. Here, the offset value represents when the slot indicated by the K0 value indicates PDSCH receptionDifference between slots (slot index). For example, referring to table 6, each entry in the TDRA table can contain only 1K 0 value. And, each SLIV can additionally have an offset value (O in table 6). For reference, for a slot indicated by a K0 value, the offset value can be omitted in SLIV. Thus, K0 of each entry in the TDRA table can be determined as { K0 } _r ，K0 _r +O _1，r ，K0 _r +O _M-1，r }. Here, K0 _r K0 representing the r-th entry, and O _i，r Representing the (slot) offset value of the ith schedule for the nth entry. M corresponds to the number of SLIV values contained in each entry.

As another example, if PDSCH can be scheduled in discontinuous slots in multi-slot scheduling, the TDRA table can have the structure of table 7.

TABLE 4

Index	(K0 ₁ ,S,L)	(K0 ₂ ,S,L)	(K0 ₃ ,S,L)	(K0 ₄ ,S,L)
					0	(0,0,14)	(1,0,14)
1	(0,0,7)	(1,0,7)
					2	(0,7,7)	(1,7,7)
3	(0,0,14)	(1,0,14)	(2,0,14)	(3,0,14)
					4	(0,0,7)	(1,0,7)	(2,0,7)	(3,0,7)
5	(0,7,7)	(1,7,7)	(2,7,7)	(3,7,7)
					6	(0,0,14)	(1,0,7)
7	(0,0,14)	(1,7,7)
					8	(0,0,7)	(1,0,14)
9	(0,0,7)	(1,7,7)
					10	(0,7,7)	(1,0,14)
11	(0,7,7)	(1,0,7)

TABLE 5

Index	K0	(S,L)	(S,L)	(S,L)	(S,L)
						0	0	(0,14)	(0,14)
1	0	(0,7)	(0,7)
						2	0	(7,7)	(7,7)
3	0	(0,14)	(0,14)	(0,14)	(0,14)
						4	0	(0,7)	(0,7)	(0,7)	(0,7)
5	0	(7,7)	(7,7)	(7,7)	(7,7)
						6	0	(0,14)	(0,7)
7	0	(0,14)	(7,7)
						8	0	(0,7)	(0,14)
9	0	(0,7)	(7,7)
						10	0	(7,7)	(0,14)
11	0	(7,7)	(0,7)

TABLE 6

Index	K0	(O,S,L)	(O,S,L)	(O,S,L)	(O,S,L)
						0	0	(0,0,14)	(1,0,14)
1	0	(0,0,7)	(1,0,7)
						2	0	(0,7,7)	(1,7,7)
3	0	(0,0,14)	(1,0,14)	(2,0,14)	(3,0,14)
						4	0	(0,0,7)	(1,0,7)	(2,0,7)	(3,0,7)
5	0	(0,7,7)	(1,7,7)	(2,7,7)	(3,7,7)
						6	0	(0,0,14)	(1,0,7)
7	0	(0,0,14)	(1,7,7)
						8	0	(0,0,7)	(1,0,14)
9	0	(0,0,7)	(1,7,7)
						10	0	(0,7,7)	(1,0,14)
11	0	(0,7,7)	(1,0,7)

TABLE 7

Index	(K0 ₁ ,S,L)	(K0 ₂ ,S,L)	(K0 ₃ ,S,L)	(K0 ₄ ,S,L)
					0	(0,0,14)
1	(0,0,7)
					2	(0,7,7)	(1,7,7)
3	(0,0,14)	(1,0,14)	(3,0,14)	(4,0,14)
					4	(0,0,7)	(2,0,7)	(4,0,7)	(5,0,7)
5	(0,7,7)	(1,7,7)	(2,7,7)	(4,7,7)
					6	(0,0,14)	(1,0,7)
7	(0,0,14)	(2,7,7)
					8	(0,0,7)	(1,0,14)
9	(0,0,7)	(1,7,7)
					10	(0,7,7)	(3,0,14)
11	(0,7,7)	(4,0,7)

For convenience of explanation, the present invention describes a case in which PDSCH is scheduled in a plurality of consecutive slots. Thus, unless otherwise indicated, the K0 value is omitted. However, the present invention also includes a case where PDSCH is scheduled in a plurality of discontinuous slots (see table 7).

Referring to fig. 15, HARQ-ACKs scheduled to be PDSCH to be received in a plurality of slots having 1 DCI can be transmitted on PUCCH in 1 slot. Here, an UL slot overlapping in time with an end point of a last PDSCH among PDSCH received in a plurality of slots can be determined as an UL slot having a K1 value of 0. In fig. 15, UL slot n+5 is a UL slot having a K1 value of 0 and corresponds to a reference slot. The user equipment can receive an indication of a K1 value from 1 DCI. In this case, HARQ-ACKs of PDSCH scheduled in multislot scheduling can be transmitted in UL slots corresponding to 1K 1.

Referring to fig. 16, HARQ-ACKs scheduled to be PDSCH to be received in a plurality of slots having 1 DCI can be transmitted on PUCCH in 2 or more slots. The method of doing so is as follows. First, PDSCH scheduled in multislot scheduling can be grouped. Here, when PDSCH is grouped, consecutive PDSCH in time order (i.e., time order) can be grouped into one group. In fig. 16, 1 DCI schedules a PDSCH to be received in 3 slots. Among the PDSCH in 3 slots, the first 2 PDSCH can be grouped into one Group (Group 0) and the last PDSCH can be grouped into one Group (Group 1). The specific grouping method described above is as follows.

In the first method, the user equipment can group PDSCH based on the number of PDSCH scheduled with 1 DCI. Here, if the number of PDSCH is greater than a certain number, the certain number of PDSCH may be grouped to form a group. For example, if the certain number is 2 and the number of PDSCH is 4, a group of PDSCH can be formed by grouping 2 PDSCH. Here, the certain number may be configured from the base station.

In the second method, the user equipment can group PDSCH with 1 DCI based on a predetermined number of groups. That is, for the user equipment, a predetermined number of groups can be configured from the base station. For example, if the number of predetermined groups is 2 and the number of PDSCH scheduled by 1 DCI is 6, 6 PDSCH may be divided into 2 groups. In this case, the PDSCH can be sequentially grouped into one group over time (time sequence), and the number of PDSCH included in the respective groups can be the same as much as possible, but can differ by as much as 1.

In a third approach, packet information can be configured for each entry in the TDRA. Specifically, each entry in the TDRA includes information for PDSCH reception in multiple slots. This can include information about which slots PDSCH are grouped. That is, together with the SLIVs of each slot, an index of a group including the SLIVs therein can be included. Referring to table 8, an index G of a group including SLIV therein can be included in each entry of the TDRA table. Here, the SLIVs belonging to g=0 correspond to group 0, and the SLIVs belonging to g=1 correspond to group 1.

TABLE 8

Index	(K0 ₁ ,S,L,G)	(K0 ₂ ,S,L,G)	(K0 ₃ ,S,L,G)	(K0 ₄ ,S,L,G)
					0	(0,0,14,0)	(1,0,14,0)
1	(0,0,7,0)	(1,0,7,0)
					2	(0,7,7,0)	(1,7,7,0)
3	(0,0,14,0)	(1,0,14,0)	(2,0,14,1)	(3,0,14,1)
					4	(0,0,7,0)	(1,0,7,0)	(2,0,7,1)	(3,0,7,1)
5	(0,7,7,0)	(1,7,7,0)	(2,7,7,1)	(3,7,7,1)
					6	(0,0,14,0)	(1,0,7,0)
7	(0,0,14,0)	(1,7,7,0)
					8	(0,0,7,0)	(1,0,14,0)
9	(0,0,7,0)	(1,7,7,0)
					10	(0,7,7,0)	(1,0,14,0)
11	(0,7,7,0)	(1,0,7,0)

The user equipment can transmit HARQ-ACKs of PDSCH included in a group on PUCCH of UL slot. Here, the method of determining UL slots includes determining UL slots temporally overlapping with an end point of a last PDSCH included in the group as UL slots (i.e., reference slots) having a K1 value of 0. That is, in fig. 16, the reference slot of group 0 is slot n+4, and the reference slot of group 1 is slot n+5.

The user equipment can receive an indication of 1 Kl value from 1 DCI. In this case, HARQ-ACKs scheduled to PDSCH to be received by 1 DCI in a plurality of slots can be transmitted in UL slots corresponding to 1K 1 for each group. For example, in fig. 16, k1=2. HARQ-ACKs of 2 PDSCHs included in group 0 are transmitted on PUCCH of slot n+4+2 (=reference slot index+k1 of group 0), and HARQ-ACKs of 1 PDSCH included in group 1 are transmitted on PUCCH of slot n+7 (=reference slot index+k1 of group 1).

The user equipment can receive an indication of the Kl value for each group from 1 DCI. In this case, for each group, HARQ-ACKs scheduled to PDSCH to be received in a plurality of slots through 1 DCI can be transmitted in UL slots corresponding to K1 of each group. For example, group 0 can be given a value of k1=1, and group 1 can be given a value of k1=2. In this case, HARQ-ACKs of 2 PDSCHs included in the group 0 are transmitted on PUCCH of the slot n+4+k1 (=reference slot index of group 0+k 1 of group 0), and HARQ-ACKs of 1 PDSCH included in the group 1 are transmitted on PUCCH of the slot n+7 (=reference slot index of group 1+k 1 of group 1).

Hereinafter, the present invention relates to a method of transmitting HARQ-ACK of PDSCH when PDSCH is scheduled using multi-slot scheduling.

In an NR wireless communication system, a user equipment can signal whether reception of a DL signal/channel (requiring HARQ-ACK feedback) is successful by transmitting a codebook including HARQ-ACK information. The HARQ-ACK codebook includes 1 bit or multiple bits indicating whether the reception of the DL channel/signal is successful. Here, the DL channel/signal (requiring HARQ-ACK feedback) may include at least 1 of i) PDSCH, ii) semi-persistent scheduling (SPS) PDSCH, and iii) PDCCH indicating SPS PDSCH release. The HARQ-ACK codebook type may be classified into a semi-static HARQ-ACK codebook (or type-1 HARQ-ACK codebook) and a dynamic HARQ-ACK codebook (or type-2 HARQ-ACK codebook). For a device, the base station can configure 1 out of 2HARQ-ACK codebook types. Based on the configured HARQ-ACK codebook type, the user equipment can generate and transmit a HARQ-ACK codebook for DL channels/signals.

Type-1 (or semi-static) HARQ-ACK codebook

When using a semi-static HARQ-ACK codebook, the base station can use the RRC signal to pre-configure the number of bits of the HARQ-ACK codebook and to determine whether each bit of the HARQ-ACK codebook is related to DL signals/channels that have been successfully received. Thus, the base station does not need to signal the information required for the HARQ-ACK codebook transmission to the user equipment every time the HARQ-ACK codebook transmission is required.

Specifically, the method for generating the type-1 HARQ-ACK codebook in the existing single slot scheduling is as follows. In single slot scheduling, DCI schedules PDSCH of 1 slot. For convenience, it is assumed that the type-1 HARQ-ACK codebook is transmitted in the slot n. Here, the slot n can be determined by a value (i.e., K1) of a PDSCH-to-harq_feedback indicator of the DCI format 1_x (PDCCH).

1) Stage 1: let the set of K1 values that the DCI can indicate be k1_set. In the case of DCI format 1_0, k1_set is {0,1,2,3,4,5,6,7}. In the case of DCI formats 1_1 and 1_2, the k1_set may be configured/set by a higher layer (e.g., RRC). The user equipment first takes out the largest K1 value (hereinafter k1_max) from the k1_set. Thereafter, k1_max is excluded from k1_set.

2) Stage 2: let the set of PDSCH candidates receivable in slot n-k1_max be R. The PDSCH candidates included in set R have a starting symbol and length within a slot according to the TDRA table. PDSCH candidates are excluded from set R if the symbols of the PDSCH candidates included in set R overlap with at least 1 of the symbols configured as UL in the semi-static UL/DL configuration.

3) And 3, the user equipment executes the steps A and B on the PDSCH candidates included in the R.

Step a: of PDSCH candidates in set R, a new HARQ-ACK occasion is allocated to the PDSCH candidate (the last symbol of the PDSCH candidate is the earliest). And, if there is a PDSCH candidate overlapping with at least 1 symbol of the PDSCH candidates in the set R (the last symbol of the PDSCH candidate is the earliest), the same HARQ-ACK occasion is allocated to the PDSCH candidate. PDSCH candidates allocated to HARQ-ACK occasions (i.e., (i) PDSCH candidates whose last symbol is the earliest, and (ii) PDSCH candidates overlapping at least 1 symbol with PDSCH candidates) are excluded from the set R.

Step B-repeat step A until set R becomes an empty set.

4) Stages 1), 2) and 3) are repeated until k1_set becomes an empty set.

Thereafter, the user equipment can generate a type-1 HARQ-ACK codebook based on the allocated HARQ-ACK occasions. For example, when receiving PDSCH corresponding to HARQ-ACK timing, the HARQ-ACK time can be configured as HARQ-ACK information of PDSCH. However, if the PDSCH corresponding to the HARQ-ACK occasion is not received, the HARQ-ACK occasion can be configured as NACK. The 1HARQ-ACK occasion may include 1 or more HARQ-ACK bits. For example, if the PDSCH includes 1 TB (or if spatial bundling is configured for the TBs in the PDSCH), the HARQ-ACK occasion may include 1HARQ-ACK bit. Further, if the PDSCH includes two TBs (and if spatial bundling is not configured), the HARQ-ACK occasion may include 2 HARQ-ACK bits. Further, when Code Block Group (CBG) -based PDSCH reception is configured, the HARQ-ACK occasion may include HARQ-ACK bits corresponding to the maximum number of CBGs that 1 PDSCH can include.

Fig. 17 illustrates PDSCH candidate positions and HARQ-ACK occasions in the case of k1_set= {0,1,2,3,4} in the existing single-slot scheduling. Referring to fig. 17, the user equipment can determine that it can be in slot n-K1 _i PDSCH candidates received in the same. K1 _i Corresponds to the ith value of the k1_set sorted in descending order. Thus, the user equipment is able to determine a set R of PDSCH candidates in each of { slot n-4,... For convenience, it is assumed that 1HARQ-ACK occasion is allocated to PDSCH candidates in each slot, and thatEach HARQ-ACK occasion is 1 bit. Thus, the type-1 HARQ-ACK codebook consists of 5 HARQ-ACK bits (o ₀ To o ₄ ) Composition is prepared.

Hereinafter, in the present invention, for convenience of explanation, 1 bit per HARQ-ACK occasion is assumed.

Meanwhile, when PDSCH is scheduled using multi-slot scheduling, if the existing method is applied as it is, the type-1 HARQ-ACK codebook cannot be properly configured. For illustration, assume that k1_set= {1,2}, is configured by RRC for the user equipment. Thus, the user equipment can receive an indication of k1=1 or k1=2 through the PDSCH-to-harq_feedback indicator within the DCI. If the TDRA table in table 4 is configured, PDSCH candidates corresponding to HARQ-ACKs that should be transmitted on the PUCCH in slot n are shown in fig. 18. However, the existing type-1 HARQ-ACK codebook generation method determines the set R of PDSCH candidates that can be received in the slot n-k1_max based only on the K1 value of the k1_set. Thus, only PDSCH candidates in slots n-2 and n-1 can be used to generate a type-1 HARQ-ACK codebook (see dashed box in fig. 18).

Hereinafter, a method of generating a type-1 HARQ-ACK codebook when PDSCH is scheduled using multi-slot scheduling is presented. For further explanation, refer to table 4 and fig. 18. A multislot scheduling operation can be configured for each cell (or component carrier). Among all cells configured for a user equipment, a cell not configured for multi-slot scheduling can operate according to an existing single-slot scheduling method.

Proposal 1 PDSCH candidates within a slot

Proposal 1 is a method of converting a PDSCH of a multislot schedule into PDSCH candidates for each slot and generating a type-1 HARQ-ACK codebook using the PDSCH candidates in each slot. For example, the type-1 HARQ-ACK codebook generation method according to proposal 1 is as follows.

1) Stage 1: the set of K1 values that can be indicated to the user equipment is called k1_set. In proposal 1, based on the k1_set and the TDRA table, the user equipment can determine an index of a slot in which a PDSCH candidate corresponding to the type-1 HARQ-ACK codebook is located/received. Let this set of slot indices be k_slots.

Specifically, the method of determining the k_slot is as follows. The user equipment is able to select 1K 1 value from the k1_set. Let the selected value of K1 be K1_a. In this case, based on k1_a and the TDRA table, the user equipment can determine in which slot the PDSCH can be received. For example, when the TDRA table includes PDSCH allocation information of up to N consecutive slots, the user equipment can determine { slot N-k1_a- (N-1), slot N-k1_a- (N-2), …, slot N-k1_a } as PDSCH allocation information based on k1_a and the TDRA table. Thus, the set of K_slots can include { K1_a+ (N-1), K1_a+ (N-2), …, K1_a }. For reference, the TDRA table may further include PDSCH allocation information for non-consecutive slots. Here, the slot N is a slot in which the type-1 HARQ-ACK codebook is transmitted, and N is the number of slots from the earliest scheduled slot to the last scheduled slot among the slots scheduled in the TDRA table. Among { time slot N-k1_a- (N-1) to time slot N-k1_a }, a time slot not scheduled by the TDRA table can be excluded. Finally, it is defined as k_time slot (k1_a) = { k1_a+ (N-1), k1_a+ (N-2), …, k1_a }. Based on the TDRA table, (N-i) corresponds to a slot index difference between the last slot to which the PDSCH can be allocated and the ith slot to which the PDSCH can be allocated. Here, the slot index difference corresponds to the difference between KO values: for example, (N-i) = (K0) _max -KO _i ). Here, K0 _max Represents a maximum value among K0, and KO _i Represents the i-th KO value (see Table 4). The k_time slot (k1_a) corresponds to the union of k_time slots determined for each k1_a/entry: kjslot (k1_a, r) = { k1_a+ (Nr-1), k1_a+ (Nr-2), …, k1_a }. Here, r denotes an entry index in the TDRA table, and Nr corresponds to the number of PDSCH/slot allocation information (e.g., KO, SLIV) included in the r-th entry in the TDRA table. Here, (Nr-i) can be defined by (K0) _max,r -KO _i,r ) Instead of. Here, K0 _max，r Represents the maximum value among the plurality of KO values corresponding to the r-th entry in the TDRA table, and KOi represents the i-th KO value among the plurality of KO values corresponding to the r-th entry in the TDRA table (see table 4).

By performing the same operation on the remaining K1 values of the k1_set, the index of the slot can be obtained for all K1 values of the k1_set, wherein PDSCH candidates can be received, and the above index can be collected/summed and included in the k_slot set.

2) Stage 2: the largest K1 value (hereinafter referred to as k1_max) is taken out of the k_time slot. Thereafter, k1_max is excluded from the k_slots, which corresponds to existing phase 1, and k_slots are used instead of the k1_set.

3) Stage 3: let the PDSCH candidate set receivable in slot n-k1_max be R. PDSCH candidates are excluded from set R if the symbols of the PDSCH candidates included in set R overlap with symbols configured as UL in the semi-static UL/DL configuration by at least one symbol.

PDSCH candidates included in the set R in the slot n-k1_max can be obtained as follows. The user equipment is able to select 1K 1 value from the k1_set. Let the selected value of K1 be k1_a. Based on the value of k1_a and the TDRA table, the user equipment can determine PDSCH candidates in multiple slots. For example, if 1 entry in the TDRA table includes PDSCH allocation information for M consecutive slots, based on k1_a and the TDRA table, the user equipment can determine { slot n-k1_a- (M-1), slot n-k1_a- (M-2), …, slot n-k1_a } as PDSCH allocation information. If 1 slot among { n-k1_a- (M-1), slot n-k1_a- (M-2), …, slot n-k1_a } slots is slot n-k1_max, PDSCH candidates included in slot n-k1_max can be included in the set R. The above procedure can be performed for all entries in the TDRA table and can be performed for all K1 values in the k1_set.

4) Stage 4: the user equipment performs steps a and B on PDSCH candidates of set R.

-step a: a new HARQ-ACK opportunity is allocated to the PDSCH candidate whose last symbol is the earliest of the PDSCH candidates in set R. And, if there is a PDSCH candidate overlapping with a PDSCH candidate (the last symbol of the PDSCH candidate is the earliest in the set R) by at least one symbol, the same HARQ-ACK occasion is allocated to the PDSCH candidate. HARQ-ACK opportunities are allocated to PDSCH candidates (i.e., (i) PDSCH candidates with the earliest last symbol and (ii) PDSCH candidates overlapping PDSCH candidates by at least one symbol) are excluded from the set R.

-step B: step a is repeated until set R becomes an empty set.

5) Stage 5: the phase 2/3/4 is repeated until the k_slot becomes an empty set.

Proposal 1 is explained with reference to fig. 19.

1) Stage 1: since 1 and 2 are configured to the K1 value (through RRC), k1_set= {1,2}. The user equipment can determine the k_slot through the following procedure.

The user equipment selects 1 value from the k1_set. Let k1_a=2. Since the entry in the TDRA table includes PDSCH allocation information for up to n=4 consecutive slots, based on k1_a=2 and the TDRA table, the user equipment can determine { slot N-k1_a- (N-1) =n-2- (4-1) =n-5, slot N-k1_a- (N-2) =n-2- (4-2) =n-4, slot N-k1_a- (N-3) =n-2- (4-3) =n-3, slot N-k1_a=n-2 } as PDSCH allocation information. Thus, the k_time slot (k1_a=2) includes {5,4,3,2}. The k_time slot (k1_a=2) corresponds to the union of k_time slots (k1_a=2, r).

-k_time slots (k1_a=2, r=0-2) { k1_a+ (Nr-1) =2+ (2-1) =3, k1_a+ (Nr-2) =2+ (2-2) =2 } or { k1_a+ (k0 max, r-K01, r) =2+ (1-0) =3, k1_a+ (k0 max, r-K02, r) =2+ (1-1) =2 }

-k_time slots (k1_a=2, r=3 to 5): {5,4,3,2}

-k_time slots (k1_a=2, r=6-11): {3,2}

The user equipment selects the remaining 1 value from the k1_set. Let the value be k1_a=1. Since the entry in the TDRA table includes PDSCH allocation information for up to n=4 consecutive slots, based on k1_a=1 and the TDRA table, the user equipment can determine { slot N-k1_a- (N-1) =n-1- (4-1) =n-4, slot N-k1_a- (N-2) =n-1- (4-2) =n-3, slot N-k1_a- (N-3) =n-1- (4-3) =n-2, slot N-k1_a=n-1 } as PDSCH allocation information. Thus, the k_time slot (k1_a=1) includes {4,3,2,1}. The k_time slot (k1_a=1) corresponds to the union of k_time slots (k1_a=1, r).

-k_time slots (k1_a=1, r=0-2) { k1_a+ (Nr-1) =1+ (2-1) =2, k1_a+ (Nr-2) =1+ (2-2) =1 }, or { k1_a+ (k0 max, r-K01, r) =1+ (1-0) =2, k1_a+ (k0 max, r-K02, r) =1+ (1-1) =1 }

-k_time slots (k1_a=1, r=3-5): {4,3,2,1}

-k_time slots (k1_a=1, r=6-11): {2,1}

Thus, finally, the k_slots include {5,4,3,2,1} (i.e., the union of k_slots (k1_a=2) and k_slots (k1_a=1)).

2) Stage 2: k1_max=5 is chosen, which is the maximum value in the k_slot. Thereafter k1_max=5 is excluded from the k_time slot.

3) Stage 3: let the set of PDSCH candidates receivable in slot n-k1_max=n-5 be R. PDSCH candidates are excluded from set R if the symbols of PDSCH candidates included in set R overlap with symbols configured as UL in the semi-static UL/DL configuration. For ease of explanation, in this example, it is assumed that all symbols in a slot are DL symbols.

PDSCH candidates included in set R in slot n-5 can be obtained as follows.

The user equipment selects 1 value from the k1_set. Let the value be k1_a=2. Entries 3, 4 and 5 of the TDRA table include PDSCH allocation information of 4 (M) consecutive slots, i.e., { slot n-k1_a- (M-1) =n-5, slot n-k1_a- (M-2) =n-4, slot n-k1_a- (M-3) =n-3, slot n-k1_a- (M-4) =n-2 }, and the remaining entry (0,1,2,6,7,8,9,10,11) includes PDSCH allocation information of 2 consecutive slots, i.e., { slot n-3, slot n-2 }. Accordingly, since entries 3, 4, and 5 of the TDRA table include PDSCH candidates of the slot n-k1_max=n-5, the PDSCH candidates included in the slot n-5 can be included in the set R. That is, the set R of PDSCH candidates that can be received in slot n-k1_max=n-5 includes the following: { (s=0, l=14), (s=0, l=7), (s=7, l=7) }. For reference, (s=0, l=14) is the PDSCH candidate of slot n-5 in entry 3 of the TDRA table, (s=0, l=7) is the PDSCH candidate of slot n-5 in entry 4 of the TDRA table, and (s=7, l=7) is the PDSCH candidate of slot n-5 in entry 5 of the TDRA table.

The remaining 1 value is selected in the k1_set. Let the value be k1_a=1. Entries 3, 4 and 5 of the TDRA table include PDSCH allocation information of 4 (M) consecutive slots, i.e., { slot n-k1_a- (M-1) =n-4, slot n-k1_a- (M-2) =n-3, slot n-k1_a- (M-3) =n-2, slot n-k1_a- (M-4) =n-1 }, and the remaining entry (0,1,2,6,7,8,9,10,11) includes PDSCH allocation information of 2 consecutive slots, i.e., { slot n-2, slot n-1 }. Therefore, since the slot corresponding to k1_a=1 does not overlap with the slot n-k1_max=n-5, there is no PDSCH candidate to be included in the set R.

Thus, r= { (s=0, l=14), (s=0, l=7), (s=7, l=7) }.

-step a: among the PDSCH candidates in the set R, HARQ-ACK occasion 0 is allocated to the PDSCH candidate (s=0, l=7) whose last symbol is the earliest. In the set R, the same HARQ-ACK timing is allocated to a PDSCH candidate (s=0, l=14) overlapping the PDSCH candidate (s=0, l=7) by at least one symbol. PDSCH candidates (s=0, l=7) and (s=0, l=14) to which HARQ-ACK opportunities are allocated are excluded from the set R. Thus, the set r= { (s=7, l=7) }

-step B: step a is repeated until set R becomes an empty set. In this example, since set R is not an empty set, step a is repeated. According to step a, HARQ-ACK occasion 1 is allocated to PDSCH candidates (s=7, l=7), and set R becomes an empty set. Thus, phase 4 ends.

5) Stage 5: the phase 2/3/4 is repeated until the k_slot becomes an empty set. In this example, k_slot= {4,3,2,1}, and thus is not an empty set. Since the K_time slot is not an empty set, phase 2/3/4 is repeated.

According to the above stage, PDSCH candidates and HARQ-ACK opportunities are determined as follows.

HARQ-ACK occasion 0: PDSCH candidates for slot n-5 (s=0, l=7), (s=0, l=14)

HARQ-ACK occasion 1: PDSCH candidate of slot n-5 (s=7, l=7)

HARQ-ACK occasion 2: PDSCH candidates for slot n-4 (s=0, l=7), (s=0, l=14)

HARQ-ACK occasion 3: PDSCH candidate of slot n-4 (s=7, l=7)

HARQ-ACK occasion 4: PDSCH candidates for slot n-3 (s=0, l=7), (s=0, l=14)

HARQ-ACK occasion 5: PDSCH candidate of slot n-3 (s=7, l=7)

HARQ-ACK occasion 6: PDSCH candidates for slot n-2 (s=0, l=7), (s=0, l=14)

HARQ-ACK occasion 7: PDSCH candidate of slot n-2 (s=7, l=7)

HARQ-ACK occasion 8: PDSCH candidates for slot n-1 (s=0, l=7), (s=0, l=14)

HARQ-ACK occasion 9: PDSCH candidates of slot n-1 (s=7, l=7)

Thus, a type-1 HARQ-ACK codebook can consist of 10 HARQ-ACK occasions.

For example, assume that DCI received by a user equipment indicates (i) entry 4 of the TDRA table and (ii) k1=2. In this case, the user equipment receives the first PDSCH (s=0, l=7) in slot n-5, the second PDSCH (s=0, l=7) in slot n-4, the third PDSCH (s=0, l=7) in slot n-3, and the fourth PDSCH (s=0, l=7) in slot n-2. The user equipment includes HARQ-ACK (o 1) of the first PDSCH in HARQ-ACK occasion 0, HARQ-ACK (o 2) of the second PDSCH in HARQ-ACK occasion 2, HARQ-ACK (o 3) of the third PDSCH in HARQ-ACK occasion 4, and HARQ-ACK (o 4) of the fourth PDSCH in HARQ-ACK occasion 6. Thus, a type-1 HARQ-ACK can consist of [ o 1N o 2N o 3N o N4N ]. Here, N represents NACK.

Further, suppose that DCI additionally received by the user equipment indicates (i) entry 5 of the TDRA table and (ii) k1=1. In this case, the user equipment receives the fifth PDSCH (s=7, l=7) in the slot n-4, receives the sixth PDSCH (s=7, l=7) in the slot n-3, receives the seventh PDSCH (s=7, l=7) in the slot n-2, and receives the eighth PDSCH (s=7, l=7) in the slot n-1. The user equipment includes HARQ-ACK (o 5) of the fifth PDSCH in HARQ-ACK occasion 3, HARQ-ACK (o 6) of the sixth PDSCH in HARQ-ACK occasion 5, HARQ-ACK (o 7) of the seventh PDSCH in HARQ-ACK occasion 7, and HARQ-ACK (o 8) of the eighth PDSCH in HARQ-ACK occasion 9. Thus, the type-1 HARQ-ACK codebook can consist of [ o 1N o o2 o5 o3 o6 o4 o 7N o ]. Here, N represents NACK.

In proposal 1, the PDSCH candidates in each slot are used to create HARQ-ACK opportunities. However, since 1 DCI can schedule PDSCH in multiple slots, it may be inefficient to use PDSCH candidates in each slot to create HARQ-ACK opportunities. For example, in fig. 19, in the user equipment, up to 8 PDSCH can be scheduled in any case. The situation is as follows:

(entry 4 in TDRA table and k1=2, entry 5 in TDRA table and k1=2)

(entry 4 in TDRA table and k1=2, entry 5 in TDRA table and k1=1)

(entry 4 in TDRA table and k1=1, entry 5 in TDRA table and k1=2)

(entry 4 in TDRA table and k1=1, entry 5 in TDRA table and k1=1)

Thus, the type-1 HARQ-ACK codebook transmitted by the user equipment need only include 8 HARQ-ACK occasions. However, according to proposal 1, 10 HARQ-ACK occasions are included. Therefore, 2 HARQ-ACK occasions are not always used for transmitting HARQ-ACK information.

Fig. 20 illustrates a HARQ-ACK codebook construction method according to proposal 1.

Referring to fig. 20, the user equipment can receive a PDCCH having the following information (S2002): (i) Index information indicating 1 entry in the TDRA table for PDSCH allocation, and (ii) timing information indicating one value in the K1-set { K1i } (i=1, 2.) for PDSCH-to-HARQ slot timing. When the slot n is indicated by the timing information, the user equipment can determine PDSCH candidates of the slot n-K1i for all K1 values in the K1-set (S2004). Thereafter, based on the determined PDSCH candidates for each slot, the user equipment can transmit a semi-static HARQ-ACK codebook in slot n.

Here, when configuring multi-slot scheduling (e.g., when at least 1 entry in the TDRA table is associated with multiple PDCCH-to-PDSCH slot timing K0 values), when determining PDSCH candidates, the K1-set can be replaced by the union of the following K-sets #i:

-K-set #i: { K1 _i +d ₁ ,K1 _i +d ₂ ,...,K1 _i +d _N },

Wherein, based on multiple PDCCH-to-PDSCH decisionsTime K0 value, d, across all entries in the TDRA table _k (k=1, 2,.,. N) corresponds to a slot index difference between a last slot to which the PDSCH can be allocated and a kth slot to which the PDSCH can be allocated.

Here, SCS applied to PDCCH and SCS applied to semi-static HARQ-ACK codebook can be the same. Further, for the determined PDSCH candidates of each slot, with reference to the PDSCH candidate having the earliest last symbol, a plurality of HARQ-ACK opportunities are sequentially allocated to non-overlapping PDSCH candidates, and a semi-static HARQ-ACK codebook can be constructed based on the plurality of HARQ-ACK opportunities. Further, when time domain bundling described later is applied to the semi-static HARQ-ACK codebook, a plurality of HARQ-ACK opportunities are allocated based on PDSCH candidates of the last slot to which the PDSCH of each bundling group can be allocated, based on each entry in the TDRA table. In addition, the wireless communication system can include a 3GPP NR-based wireless communication system.

Proposal 2: PDSCH candidates in all slots

Proposal 2 is a method of generating a type-1 HARQ-ACK codebook using PDSCH candidates in all slots. For example, the type-1 HARQ-ACK codebook generation method according to proposal 2 is as follows.

1) Stage 1: the user equipment can include PDSCH candidate pairs that can be scheduled in the set R. Here, the PDSCH candidate pair is a group obtained by grouping PDSCH candidates that can be scheduled according to 1 entry in the TDRA table. Thus, a PDSCH candidate pair represents a PDSCH candidate whose reception can be scheduled in multiple slots. And, if a symbol of a PDSCH candidate included in the PDSCH candidate pair included in the set R overlaps with a symbol configured as UL in the semi-static UL/DL configuration by at least one symbol, the PDSCH candidate is excluded from the PDSCH candidate pair. If all PDSCH candidates are excluded from the PDSCH candidate pair, then the PDSCH candidate pair is excluded from the set R.

2) Stage 2: the user equipment performs steps a and B on PDSCH candidates of set R.

-step a: 1 PDSCH candidate pair is taken out of PDSCH candidate pairs of set R. A new HARQ-ACK opportunity is allocated to the PDSCH candidate pair. And, if there is a PDSCH candidate pair overlapping at least one symbol with the PDSCH candidate in the set R, the same HARQ-ACK occasion is allocated to the corresponding PDSCH candidate pair. HARQ-ACK opportunities are assigned to PDSCH candidate pairs that are excluded from the set R.

-step B: step a is repeated until set R becomes an empty set.

Unlike in proposal 1, in proposal 2, the PDSCH candidate pair corresponds to the HARQ-ACK timing. Also, each PDSCH candidate pair can include a different number of PDSCH candidates. Thus, the number of PDSCH candidates that should be indicated by one HARQ-ACK occasion may be different. For this, the number of PDSCH candidates that should be indicated by 1 HARQ-ACK occasion can be determined based on the maximum number of PDSCH candidates among the PDSCH candidate pairs corresponding to 1 HARQ-ACK occasion.

In step a, the user equipment should select 1 PDSCH candidate pair from the set R. For this purpose, at least the following methods or combinations of the following methods can be considered.

In the first method, a PDSCH candidate pair including the first starting PDSCH candidate can be selected. By doing so, HARQ-ACK opportunities can be preferentially allocated to PDSCH candidates at the earliest point in time.

In the second method, a PDSCH candidate pair can be selected, the end time point of which is earliest. By doing so, HARQ-ACK opportunities can be preferentially allocated to PDSCH candidates that end earliest in time.

In a third method, a PDSCH candidate pair with the least symbol can be selected. By doing so, the selected PDSCH candidate pair can have minimal overlap with other PDSCH candidate pairs.

In the fourth method, the PDSCH candidate pair with the most symbols can be selected. By doing so, the selected PDSCH candidate pair can overlap with the maximum number of PDSCH candidate pairs, and thus a large number of PDSCH candidates can be excluded from the set R.

In the fifth method, the PDSCH candidate pair with the largest number of slots can be selected. As described above, the number of PDSCH candidates that the HARQ-ACK opportunity should represent is determined by the number of PDSCH candidates that the PDSCH candidate pair has. Thus, PDSCH candidate pairs with a smaller number of overlapping slots can be found, focusing on PDSCH candidate pairs with more slots.

In the sixth method, the PDSCH candidate pair with the lowest index of the TDRA table can be selected. This may be configured when the base station configures the TDRA table.

Time domain bundling

When the user equipment generates the type-1 HARQ-ACK codebook, time domain bundling can be configured from the base station for the user equipment. Time domain bundling is a type of bundling HARQ-ACKs of PDSCH into one HARQ-ACK bit (e.g., binary "AND" operation) AND generating (i.e., if all HARQ-ACKs are ACKs, 1HARQ-ACK bit is ACK, otherwise, 1HARQ-ACK bit is NACK) as HARQ-ACKs of 1HARQ-ACK bit, AND transmitting the HARQ-ACK bit. Here, PDSCH to which time domain bundling is applied can be PDSCH of the same slot or PDSCH of different slots. Here, PDSCH to which time domain bundling is applied is PDSCH scheduled with 1 DCI and is adjacent PDSCH when PDSCH is aligned in time. For example, when PDSCH scheduled with 1 DCI is pdsch#0 in slot n, pdsch#1 in slot n+1, pdsch#2 in slot n+2, and pdsch#3 in slot n+3, among 4 PDSCHs, the user equipment can bundle HARQ-ACKs of { pdsch#0 in slot n, pdsch#1 in slot n+1 } into 1HARQ-ACK bit, and bundle pdsch#2 in slot n+2, pdsch#3 in slot n+3 } into one HARQ-ACK bit. Thus, four HARQ-ACK bits are generated for 4 PDSCH, but only 2 HARQ-ACK bits can be transmitted through time domain bundling.

For a user equipment, at least one of the following information can be configured for time domain bundling from a base station.

As the first information, the base station can configure the number of bundled HARQ-ACKs (or the number of PDSCH) for time domain bundling. Let it be N _bundle 。N _bundle Can be 1 of the values 1, 2, 4 or 8. When Nbindle is configured for user equipment, the user equipment will N _bundle The HARQ-ACK of the PDSCH is bundled into 1 HARQ-ACK bit and the HARQ-ACK bit is transmitted. Suppose utilization of1 DCI schedules M PDSCH. If M is N _bundle Is a multiple of (M mod N _bundle =0), then the user equipment can pass through the pair N _bundle PDSCH performs grouping to generate 1 bundled HARQ-ACK, and generates a total of M/N _bundle And bundled HARQ-ACKs. However, if M is not N _bundle Is a multiple of (M mod Nbindle)>0) The user equipment can group PDSCH as follows. For reference, pdsch#0, pdsch#1, …, pdsch# (M-1) are arranged in time order here.

In the first method, N is obtained by chronologically aligning N _bundle PDSCH is packetized to generate one bundled HARQ-ACK. If the number of remaining PDSCH is less than N _bundle Then 1 bundled HARQ-ACK is generated by grouping the remaining PDSCH. More specifically, the PDSCH # is obtained by combining PDSCH #0, PDSCH #1, …, pdsch# (N) _bundle -1) } grouping to generate 1 bundled HARQ-ACKs. By { PDSCH # (N) _bundle )、PDSCH#(N _bundle +1)、…、PDSCH#(2*N _bundle -1) } grouping to generate 1 bundled HARQ-ACKs. The grouping continues as such and by grouping { PDSCH # (floor (M/N) _bundle )*N _bundle )，PDSCH#(floor(M/N _bundle )*N _bundle +1), …, pdsch# (M-1) } to generate 1 bundled HARQ-ACKs. As a result, total ceil (M/N) _bundle ) And bundled HARQ-ACK bits.

In the second method, k=ceil (M/N) can be generated by grouping PDSCH in time order _bundle ) And groups. The number of PDSCH included in each group can be ceil (M/K) PDSCH or floor (M/K) PDSCH. M mod K groups can be generated by grouping ceil (M/K) PDSCHs in time order, and K- (M mod K) groups can be generated by grouping floor (M/K) PDSCHs in subsequent time order. 1 bundled HARQ-ACK can be generated by HARQ-ACKs in the bundling group. As a result, a total of ceil (M/Nbundle) bundled HARQ-ACK bits are generated.

As the second information, the base station can configure the number of bundled HARQ-ACKs (or the number of PDSCH/bundling groups) for time domain bundling. Let this be N _group 。N _group Can be 1 value of 1, 2, 4 or 8. When configuring N for user equipment _group When the user equipment is able to generate N by grouping M PDSCH _group And PDSCH groups. For reference, if M is less than N _group Then M PDSCH groups are generated by grouping 1 PDSCH and the next N _group The M groups do not include PDSCH. The HARQ-ACK of the group excluding the PDSCH may be configured as NACK. The HARQ-ACK of the group excluding the PDSCH may not be transmitted to the base station.

In the first method, one bundled HARQ-ACK can be generated by grouping k=ceil (M/nmgroup) PDSCHs in time sequence. If the number of remaining PDSCHs is less than K, 1 bundled HARQ-ACKs can be generated by grouping the remaining PDSCHs. For example, 1 bundled HARQ-ACK can be generated by grouping { PDSCH#0, PDSCH#1,. }, PDSCH# (K-1), and may generate a bundled HARQ-ACK by grouping { pdsch# (K), pdsch# (k+1), …, pdsch# (2*K-1) }. The grouping continues as such, and 1 bundled HARQ-ACK is generated by grouping { pdsch# (floor (M/K) ×k), pdsch# (floor (M/K) ×k+1), …, pdsch# (M-1) }. As a result, a total of N can be generated _group And bundled HARQ-ACK bits.

In the second method, N can be generated by grouping PDSCH in time order _group A group. The number of PDSCHs included in each group can be ceil (M/Ngroup) or floor (M/N) _group ) PDSCH. By time-sequential alignment of ceil (M/N) _group ) Grouping the PDSCHs to generate M mod N _group Groups, and can be made by sequentially checking floor (M/N) _group ) Grouping the PDSCHs to generate N _group -(M mod N _group ) And groups. The 1 bundled HARQ-ACKs can be generated by bundling the HARQ-ACKs within the group. As a result, a total of N is generated _group And bundled HARQ-ACK bits.

As the third information, the base station can configure a time interval for time domain bonding. The time interval can be configured in units of time slots. The time interval can be referred to as a bundling window. Is configured by taking time slot as a unitIs of time interval N _slot . The user equipment can be arranged to be included in N by pairing _slot PDSCH in a slot is grouped to generate 1 group. If at least 1 PDSCH is included in the group, the user equipment can bundle HARQ-ACKs of the PDSCH into one HARQ-ACK. The HARQ-ACKs of the group excluding the PDSCH can be configured as NACKs. In addition, HARQ-ACKs of groups not including PDSCH can not be transmitted to the base station. The user equipment can determine N as follows _slot Time slots.

In the first method, for each N starting from time slot 0 of the frame _slot The consecutive slots, the user equipment can generate groups by grouping PDSCH included in the slots. That is, the transmission can be performed by dividing the slot i by N _slot Time slot i x N _slot +1, …, time slot (i+1) N _slot PDSCH included in-1 is grouped to generate groups. Here, i is an integer.

In the second method, for each N starting from slot k of the frame _slot The user equipment can generate groups by grouping PDSCH included in the slots in consecutive slots. That is, the transmission can be performed by dividing the slot i by N _slot +k, time slot i.times.N _slot +k+1, …, time slot (i+1) N _slot PDSCH included in-1+k is grouped to generate groups. For reference, 1 group can be generated by grouping PDSCH included in slot 0, slot 1, …, slot k-1. Here, i is an integer. Here, k may be a value configured by the base station for the user equipment, or a value determined based on an index of a slot in which the first PDSCH is scheduled, or a value determined based on an index of a slot in which a PDCCH of the PDSCH is scheduled, or a value determined based on an index of a slot in which a PUCCH of the HARQ-ACK including the PDSCH is transmitted. k is an integer and corresponds to a slot offset.

For example, if X is a value determined based on an index of a slot in which the first PDSCH is scheduled, it may be k=x. Since the first PDSCH is scheduled in slot 3, N _slot PDSCH included in time slot=4 starts from time slot 3, i.e., time slot 3, time slot 4, time slot 5, and time slot 6 can be divided into 1 group, and the next N _slot PD included in time slot=4SCH, i.e., slot 7, slot 8, slot 9 and slot 10 can be divided into 1 group. k is an integer and corresponds to a slot offset.

For example, if X is a value determined based on an index of a slot in which a PDCCH of PDSCH is scheduled to transmit, it may be k=x. Since the first PDSCH is scheduled in slot 1, N _slot PDSCH included in time slot=4 starts from time slot 1, i.e., time slot 1, time slot 2, time slot 3, and time slot 4 can be divided into 1 group, and in the next N _slot PDSCH included in=4 slots, i.e., slot 5, slot 6, slot 7, and slot 8 can be divided into 1 group.

For example, if an index of a slot in which a PUCCH of HARQ-ACK including PDSCH is transmitted is X, it may be k=x mod Nslot. Since PUCCH is scheduled in slot 10, k=10 mod 4=2. Thus N _slot PDSCH included in time slot=4 starts from time slot 2, i.e. time slot 2, time slot 3, time slot 4 and time slot 5 can be divided into 1 group, and in the next N _slot PDSCH included in=4 slots, i.e., slot 6, slot 7, slot 8, and slot 9 can be divided into 1 group.

Referring to fig. 21, assume that N is configured for a user equipment _slot =3. Here, k=n-5. That is, the bundling window can be configured by grouping 3 slots starting from slot n-5. For example, slot n-5, slot n-4, and slot n-3 can be included in bundling window #A, and slot n-2, slot n-1, and slot n can be included in bundling window #B. Accordingly, 1 bundled HARQ-ACK bit can be generated by grouping PDSCH included in bundling window #a, and 1 bundled HARQ-ACK bit can be generated by grouping PDSCH included in bundling window #b.

Hereinafter, a method of generating a type-1 HARQ-ACK codebook by a user equipment when a time domain bundling is configured will be described. For explanation, in the present invention, it is assumed that the user equipment has generated a group in which PDSCH is grouped based on the first information, the second information, and the third information. For convenience, the PDSCH included in each group is denoted by { pdsch#n, pdsch# (n+1) }. The number of PDSCH included in each group is k.

In the present invention, the user equipment can select 1 PDSCH included in the group as a representative. In this case, the user equipment can generate a type-1 HARQ-ACK codebook based on the SLIVs corresponding to the PDSCH. The method of selecting a representation from among PDSCH included in the group can include at least one of the following.

In the first method, the PDSCH (e.g., of the first slot) that is earliest in time among the PDSCHs included in the group can be selected as a representative. For example, if PDSCH included in the group is { pdsch#n, pdsch# (n+1), …, pdsch# (n+k-1) }, pdsch#n can be selected as a representative.

In the second method, PDSCH farthest in time (e.g., last slot) among PDSCH included in the group can be selected as a representative. For example, if PDSCH included in the group is { pdsch#n, pdsch# (n+1), …, pdsch# (n+k-1) }, pdsch# (n+k-1) can be selected as a representative.

In the third method, the PDSCH occupying the most symbol among the PDSCHs included in the group can be selected as a representative. If the number of symbols occupied by the plurality of PDSCH is the same, one of PDSCH which is earliest in time or PDSCH which is farthest in time can be selected as a representative.

In the fourth method, the PDSCH occupying the least symbol among the PDSCHs included in the group can be selected as a representative. If the number of symbols occupied by the plurality of PDSCH is the same, one of PDSCH that is earliest in time or PDSCH that is farthest in time can be selected as a representative.

In the fifth method, among the PDSCH in the first, second, third and fourth methods, a PDSCH overlapping with a symbol configured as UL according to the semi-static UL/DL configuration by at least one symbol may be excluded.

Referring to fig. 22, it is assumed that N is configured for the user equipment according to the second information _slot =3. Here, k=n-5. That is, the bundling window can be configured by grouping 3 slots starting from slot n-5. For example, slot n-5, slot n-4, and slot n-3 can be included in bundling window #A, and slot n-2, slot n-1, and slot n can be included in bundling window #AIn bundling window #b. The user equipment can select a temporally latest PDSCH candidate among PDSCH candidates in the bundling window as a representative PDSCH (representative SLIV). For example, if the K1 value is 2 and the TDRA index (or entry) =3, 4 PDSCH candidates can be scheduled in slot n-5, slot n-4, slot n-3, and slot n-2. Among the PDSCH candidates, the first 3 PDSCH candidates (PDSCH candidates scheduled in slot n-5, slot n-4, and slot n-3) belong to the bundling window #a. Therefore, the PDSCH candidate in the slot n-3 (which is the temporally latest PDSCH candidate among the PDSCH candidates) can be selected as the representative PDSCH (representative SLIV). Also, 1 PDSCH candidate (i.e., PDSCH candidate scheduled in slot n-2) belongs to the bundling window #b. Therefore, the PDSCH candidate in the slot n-2, which is the temporally latest PDSCH candidate among the PDSCH candidates, can be selected as the representative PDSCH (representative SLIV). A representative PDSCH (representative SLIV) selected in this way is shown in fig. 22.

In the following description, the selected PDSCH (corresponding SLIV) is referred to as a representative PDSCH (or representative SLIV). For every 1 group, 1 representative PDSCH (or representative SLIV) is determined. The user equipment can generate a type-1 HARQ-ACK codebook based on the representative SLIV as follows.

1) Stage 1: the set of K1 values that can be indicated to the user equipment is called k1_set. Based on the k1_set and the TDRA table, the user equipment can determine an index of a slot in which a representative PDSCH candidate (representative SLIV candidate) is received. In this case, let the set of indexes of slots in which the representative PDSCH candidate (representative SLIV candidate) is received be k_slots.

2) Stage 2: the largest K1 value (hereinafter referred to as k1_max) is taken out of the k_time slot. Thereafter, the k1_max value is excluded from the k_time slot.

3) Stage 3: let the set of representative PDSCH candidates (or representative SLIV candidates) that can be received in slot n-Kl _ max be R. If the symbol of the representative PDSCH candidate (or representative SLIV candidate) included in the set R overlaps with the symbol configured as UL by at least one symbol in the semi-static UL/DL configuration, the representative PDSCH candidate (representative SLIV candidate) is excluded from the set R.

The representative PDSCH candidates (or representative SLIV candidates) included in the set R can be obtained as follows. A K1 value can be selected from the k1_set. Let the selected value of K1 be K1_a. Based on the k1_a value and the TDRA table, the user equipment can determine a representative PDSCH candidate (or representative SLIV candidate) in the slot n-k1_max.

4) Stage 4: the user equipment performs steps a and B on the representative PDSCH candidates (or representative SLIV candidates) included in the set R.

Step A: among the representative PDSCH candidates (representative SLIV candidates) of the set R, a new HARQ-ACK opportunity is allocated to the representative PDSCH candidate (representative SLIV candidate) whose last symbol is the earliest. And in the set R, if there is at least one symbol overlapping the representative PDSCH candidate (representative SLIV candidate) with the representative PDSCH candidate (representative SLIV candidate) (the last symbol of the representative is the earliest/foremost), the same HARQ-ACK occasion is allocated to the representative PDSCH candidate (representative SLIV candidate). The representative PDSCH candidate (representative SLIV candidate) assigned to the HARQ-ACK occasion (i.e., (i) the last symbol of the representative PDSCH candidate (representative SLIV candidate) is earliest, and (ii) the representative PDSCH candidate (representative SLIV candidate) overlaps that representative PDSCH candidate (representative SLIV candidate) by at least one symbol) is excluded from the set R.

-step B: step a is repeated until set R becomes an empty set.

5) Stage 5: the phase 2/3/4 is repeated until the K slot becomes an empty set.

6) Stage 6: the user equipment can allocate B HARQ-ACK bits to a candidate of the representative PDSCH (or a representative SLIV candidate), to which the same HARQ-ACK occasion is allocated. Here, B is the maximum value of the number of PDSCH included in the group including the candidate of the representative PDSCH (or representative SLIV candidate) allocated to the same HARQ-ACK occasion.

Referring to fig. 23, a more detailed description will be made. First, it is assumed that the user equipment has determined a representative PDSCH candidate (representative SLIV candidate) according to fig. 22.

1) Stage 1: for the user equipment, 1 and 2 are configured to be the K1 value, and thus k1_set= {1,2}. When the K1 value is 2, the representative PDSCH candidate (or representative SLIV candidate) is located in time slot n-3 and time slot n-2. Thus, the K1 value for this slot is 3 and 2. Both values may be included in the k_time slot. Further, when the K1 value is 1, the representative PDSCH candidate (or representative SLIV candidate) is located in time slot n-3 and time slot n-1. Thus, the K1 value of the slot is 3 and 1. Both values may be included in the k_time slot. Thus, when k1_set= {1,2} is configured, k_slot is {1,2,3} as the union of the two.

2) Stage 2: k1_max=3 is chosen, which is the maximum value in the k_slot. Thereafter, k1_max is excluded from k_slo.

3) Stage 3: let the set of representative PDSCH candidates (or representative SLIV candidates) that can be received in slot n-k1_max=n-3 be R. If the symbol of the representative PDSCH candidate (or representative SLIV candidate) included in the set R overlaps with the symbol configured as UL by at least one symbol in the semi-static UL/DL configuration, the representative PDSCH candidate (or representative SLIV candidate) is excluded from the set R. For ease of explanation, in this example, it is assumed that all symbols in a slot are downlink symbols.

The representative PDSCH candidates (or representative SLIV candidates) included in the set R in the slot n-3 are r= { (s=0, l=14), (s=0, l=7), (s=7), l=7) }.

4) Stage 4: the user equipment performs steps a and B on representative PDSCH candidates (representative SLIV candidates) included in the set R.

-step a: among the representative PDSCH candidates of the set R, HARQ-ACK opportunity 0 is allocated to the representative PDSCH candidate (representative SLIV candidate) (s=0, l=7), the last symbol of which is the earliest. In the set R, the same HARQ-ACK timing is allocated to a representative PDSCH candidate (representative SLIV candidate) (s=0, l=14) overlapping with a representative PDSCH candidate (representative SLIV candidate) whose last symbol is the earliest (s=0, l=7) by at least one symbol. Representative PDSCH candidates (representative SLIV candidates) (s=0, l=7) and (s=0, l=14) allocated to HARQ-ACK occasions are excluded from the set R. Thus, the set r= { (s=7, l=7) }.

-step B: step a is repeated until set R becomes an empty set. In this example, since set R is not an empty set, step a is repeated. According to step a, HARQ-ACK occasion 1 is allocated to a representative PDSCH candidate (or representative SLIV candidate) (s=7, l=7), and set R becomes an empty set. Thus, stage 4 ends.

5) Stage 5: the phase 2/3/4 is repeated until the k_slot becomes an empty set. In an example, k_slot= {2,1}, and thus is not an empty set. Since the K_time slot is not an empty set, phase 2/3/4 is repeated.

HARQ-ACK occasion 0: representative PDSCH candidates for slot n-3 (s=0, l=7), (s=0, l=14)

HARQ-ACK occasion 1: representative PDSCH candidate of slot n-3 (s=7, l=7)

HARQ-ACK occasion 2: representative PDSCH candidates for slot n-2 (s=0, l=7), (s=0, l=14)

HARQ-ACK occasion 3: representative PDSCH candidate of slot n-2 (s=7, l=7)

HARQ-ACK occasion 4: representative PDSCH candidates for slot n-1 (s=0, l=7), (s=0, l=14)

HARQ-ACK occasion 5: representative PDSCH candidate of slot n-1 (s=7, l=7)

Thus, a type-1 HARQ-ACK codebook may consist of 6 HARQ-ACK occasions.

6) Stage 6: the user equipment can determine the number of HARQ-ACK bits per HARQ-ACK occasion as follows. The representative PDSCH candidates included in HARQ-ACK occasion 0 are (s=0, l=7), (s=0, l=14), and the TDRA index (or entry) to which the representative PDSCH candidates belong within the bundling window is 0, 1, 3, 4, 6, 7, 8, 9 when k1=2, and 3 and 4 when k1=1. Where when k1=2 and the TDRA index is 3, there are up to 3 PDSCH candidates within the bundling window, and thus HARQ-ACK occasion 0 includes 3 HARQ-ACK bits. In the same way, HARQ-ACK occasion 1 can comprise 3 HARQ-ACK bits, HARQ-ACK occasion 2 can comprise 1HARQ-ACK bit, HARQ-ACK occasion 3 can comprise 1HARQ-ACK bit, HARQ-ACK occasion 4 can comprise 2 HARQ-ACK bits, and HARQ-ACK occasion 5 can comprise 2 HARQ-ACK bits.

Thus, the type-1 HARQ-ACK codebook can include a total of 12 HARQ-ACK bits.

Type-2 (or dynamic) HARQ-ACK codebook

For the user equipment, a dynamic HARQ-ACK codebook can be configured. When using the dynamic HARQ-ACK codebook, the base station can signal information necessary for generating the HARQ-ACK codebook through a PDCCH (or DCI). Specifically, the base station can signal information necessary for HARQ-ACK codebook generation through a Downlink Assignment Index (DAI) field of a PDCCH (or DCI). In particular, the DAI can indicate i) the number of bits of the HARQ-ACK codebook, and/or ii) information about the position of HARQ-ACK bits corresponding to the DAI within the HARQ-ACK codebook. Here, the HARQ-ACK bit corresponding to the DAI can represent (i) the HARQ-ACK bit for the PDSCH scheduled by the DAI, or (ii) the HARQ-ACK bit for the DAI. DAI can be divided into trans-DAI and all-DAI. The user equipment can determine the number of bits of the dynamic HARQ-ACK codebook based on the DAI of the PDCCH (or DCI).

Meanwhile, the type-2 HARQ-ACK codebook can be composed of two sub-codebooks. Information required to construct each sub-codebook (e.g., sub-codebook size (e.g., number of bits), HARQ-ACK bit positions within the sub-codebook) can be obtained based on DAI information within each DCI.

The first sub-codebook includes HARQ-ACK bits of PDSCH according to TB-based transmission. Here, PDSCH is scheduled separately by each DCI. That is, 1 PDSCH is scheduled by 1 DCI (hereinafter, referred to as single PDSCH scheduling). Further, if PDSCH according to TB-based transmission is configured to include 1 TB, each PDSCH can generate 1 HARQ-ACK bit, and if PDSCH according to TB-based transmission is configured to be in at least one cell (cell) (and if spatial bundling is not configured), each PDSCH can generate 2 HARQ-ACK bits. Thus, each DCI scheduling a TB-based transmission can generate P HARQ-ACK bits (if not configured for spatial bundling). Here, P is the maximum number of TBs included in the PDSCH. For reference, if the number of TBs scheduled by DCI is less than P, HARQ-ACK bits corresponding to the number of insufficient TBs (i.e., unscheduled TBs) are configured as NACK.

The second sub-codebook includes HARQ-ACK bits of PDSCH according to Code Block Group (CBG) based transmission. For user equipment, configuration can be made such that PDSCH according to CBG-based transmission in cell c includes N (max) per TB _CBG,c CBGs. Let (maximum number of TBs for cell c) N for all cells for which CBG based transmission is configured _CBG,c Has a maximum value of N _CBG,max . User equipment generates N for each DCI scheduling CBG-based transmission _CBG,max HARQ-ACK bits. For reference, if the number of CBGs scheduled by DCI is less than N _CBG，max The HARQ-ACK bit corresponding to the insufficient number of CBGs is configured as NACK.

Hereinafter, a method of generating a type-2 HARQ-ACK (sub-) codebook when a plurality of PDSCHs are scheduled using 1 DCI (i.e., multi-slot scheduling; multi-PDSCH scheduling) will be described. For convenience of explanation, in the following description, the second sub-codebook is described as including both CBG-based HARQ-ACK bits and HARQ-ACK bits based on multi-PDSCH scheduling. However, this is an example, and in an actual wireless communication environment, the second sub-codebook can include only HARQ-ACK bits based on multi-PDSCH-scheduling depending on scheduling conditions. In the first method, when a plurality of PDSCHs are scheduled using 1 DCI, HARQ-ACKs of the plurality of PDSCHs can always be transmitted in the second sub-codebook. Here, the second sub-codebook may be modified as follows.

The second sub-codebook includes (i) HARQ-ACK bits of PDSCH according to CBG-based transmission and (ii) HARQ-ACK bits of multiple PDSCH when multiple PDSCH are scheduled with 1 DCI. For the user equipment, configuration can be made such that PDSCH according to CBG-based transmission for cell c includes N (max) per TB _CBG,c CBG. Let (maximum number of TBs for cell c) N for all cells for which CBG based transmission is configured _CBG,c Has a maximum value of N _CBG,max . Further, when a plurality of PDSCHs are scheduled using 1 DCI, the maximum value of the number of PDSCHs scheduled by 1 TDRA index is made N _{multi-PDSCH，max} 。

The user equipment can generate max (N) for each DCI indicating CBG-based transmission _CBG，max， N _{multi-PDSCH，max} ) HARQ-ACK bits. The user equipment can generate max (N _CBG，max， N _{multi-PDSCH，max} ) HARQ-ACK bits. If the number of CBGs scheduled by DCI is less than max (N _CBG，max， N _{multi-PDSCH，max} ) The HARQ-ACK bits corresponding to an insufficient number (CBG) are configured as NACKs. If the number of PDSCHs scheduled by DCI indicating multi-PDSCH scheduling is less than max (N _CBG，max ，N _{multi-PDSCH，max} ) The HARQ-ACK bits corresponding to an insufficient number (PDSCH) are configured as NACKs.

In the second method, when multiple PDSCH are scheduled using 1 DCI, the user equipment can selectively transmit HARQ-ACKs of multiple PDSCH through the first sub-codebook or the second sub-codebook according to the number of PDSCH. Here, the first and second sub-codebooks can be modified as follows.

When scheduling PDSCH (i.e., multi-PDSCH) with 1 DCI, if the number of PDSCH is X or less, the first sub-codebook can include (i) HARQ-ACK bits of PDSCH according to TB-based transmission and (ii) HARQ-ACK bits of multiple PDSCH. Here, it is assumed that a PDSCH according to a TB-based transmission is configured to include P number of TBs. Here, P is the maximum number of TBs included in the PDSCH. Thus, each DCI scheduling a TB-based transmission can generate max { P, X } HARQ-ACK bits. For reference, if the number of TBs scheduled by DCI is less than max { P, X }, HARQ-ACK bits corresponding to an insufficient number (PDSCH) are configured as NACK. For reference, DCI indicating multi-PDSCH scheduling schedules PDSCH of X or less. If the number of PDSCHs scheduled by DCI indicating multi-PDSCH scheduling is less than max { P, X }, HARQ-ACK bits corresponding to an insufficient number (PDSCH) are configured as NACKs.

When multiple PDSCH are scheduled using 1 DCI, if the number of PDSCH exceedsOver X, the second sub-codebook includes (i) HARQ-ACK bits of PDSCH according to CBG based transmission, and (ii) HARQ-ACK bits of multiple PDSCH. For the user equipment, configuration can be made such that PDSCH according to CBG-based transmission for cell c includes N (max) per TB _CBG,c CBG. Let (maximum number of TBs for cell c) N for all cells for which CBG based transmission is configured _CBG,c Has a maximum value of N _CBG,max . When a plurality of PDSCHs are scheduled using DCI, the maximum value of the number of PDSCHs scheduled by 1 TDRA index is N _{multi-PDSCH，max} . For reference, N _{multi-PDSCH,max} Is a value greater than X.

The user equipment generates max (N) for each DCI indicating CBG-based transmission _CBG，max， N _{multi-PDSCH，max} ) HARQ-ACK bits. The user equipment generates max (N) of DCI for indicating multiple PDSCH scheduling _CBG，max ，N _{multi-PDSCH，max} ) HARQ-ACK bits. If the number of CBGs scheduled by DCI is less than max (N _CBG，max ，N _{multi-PDSCH，max} ) The HARQ-ACK bits corresponding to an insufficient number (CBG) are configured as NACKs. If the number of PDSCHs scheduled by DCI indicating multi-PDSCH scheduling is less than max (N _CBG，max ，N _{multi-PDSCH，max} ) The HARQ-ACK bits corresponding to an insufficient number (PDSCH) are configured as NACKs.

As previously described, it can be preferably set to x=p. That is, if the multi-PDSCH scheduling DCI schedules PDSCHs less than or equal to P PDSCHs, HARQ-ACKs of the multi-PDSCH are included in the first sub-codebook, and if the multi-PDSCH scheduling DCI schedules more than P PDSCHs, HARQ-ACKs of the multi-PDSCH are included in the second sub-codebook.

When the type-2 HARQ-ACK codebook and the time domain bundling are simultaneously configured, the second method can be modified as follows. Time domain bundling is described above.

In the modified second method, when multiple PDSCHs are scheduled using 1 DCI, the user equipment can selectively transmit HARQ-ACKs of multiple PDSCHs through the first or second sub-codebook according to the number of bundled HARQ-ACK bits in the DCI. The number of bundled HARQ-ACK bits is determined according to the number of PDSCH/bundled groups. Here, the first and second sub-codebooks can be modified as follows.

When scheduling PDSCH with 1 DCI, if bundled HARQ-ACK according to DCI is less than or equal to X bits, the first sub-codebook includes (i) HARQ-ACK bits of PDSCH according to TB-based transmission, and (ii) bundled HARQ-ACK bits. Here, it is assumed that a PDSCH according to a TB-based transmission is configured to include (maximum) P TBs. Here, P is included in the maximum number of TBs in the PDSCH. Thus, each DCI scheduling a TB-based transmission can generate max { P, X } HARQ-ACK bits. For reference, if the number of TBs scheduled by DCI is less than max { P, X }, HARQ-ACK bits corresponding to an insufficient number of (TBs) are configured as NACK. Each DCI scheduling a TB-based transmission can generate max { P, X } bundled HARQ-ACK bits. For reference, DCI indicating multi-PDSCH scheduling corresponds to bundled HARQ-ACK bits of X bits or less. If the number of bundled HARQ-ACK bits corresponding to DCI indicating multi-PDSCH scheduling is less than max { P, X }, bundled HARQ-ACK bits corresponding to an insufficient number (PDSCH) are configured as NACK.

When a plurality of PDSCHs are scheduled using 1 DCI, if the bundled HARQ-ACKs according to the DCI exceeds X, the second sub-codebook includes (i) HARQ-ACK bits of the PDSCH according to the CBG based transmission, and (ii) the bundled HARQ-ACK bits. For the user equipment, configuration can be made such that PDSCH according to CBG-based transmission for cell c includes N (max) per TB _CBG,c CBG. Let (maximum number of TBs for cell c) N for all cells for which CBG based transmission is configured _CBG,c Has a maximum value of N _CBG,max . Yielding a maximum of N among the numbers of bundled HARQ-ACK bits corresponding to 1 TDRA index when multiple PDSCH are scheduled with DCI _{bundled，max} . For reference, N _bundled,max Is a value greater than X.

The user equipment generates max (N) for each DCI indicating CBG-based transmission _CBG，max， N _{bundled，max} ) HARQ-ACK bits. The user equipment generates max (N) of DCI for indicating multiple PDSCH scheduling _CBG，max ，N _{bundled，max} )HARQ-ACKBits. If the number of CBGs scheduled by DCI is less than max (N _CBG，max ，N _{bundled，max} ) The HARQ-ACK bits corresponding to an insufficient number (CBG) are configured as NACKs. If the number of bundled HARQ-ACKs corresponding to DCI indicating multi-PDSCH scheduling is less than max (N _CBG，max ，N _{bundled，max} ) The bundled HARQ-ACK bits corresponding to the insufficient number are configured as NACKs.

For example, it is assumed that the user equipment always generates 1 bundled HARQ-ACK bits for DCI indicating multi-PDSCH scheduling. This corresponds to the case where the number of PDSCH/bundling groups for time domain bundling is configured to be 1, for example. In this case, bundled HARQ-ACK bits can be included in the first sub-codebook (e.g., x=1). In other cases (e.g., when the number of PDSCH/bundling groups for time domain bundling is complex), bundled HARQ-ACK bits can be included in the second sub-codebook.

Fig. 24 illustrates an exemplary HARQ-ACK codebook transmission procedure according to the present invention.

Referring to fig. 24, the user equipment can receive a single PDSCH scheduling (S2402). Further, the user equipment can receive multiple PDSCH scheduling (S2404). Here, it is assumed that TB-based HARQ-ACK feedback is applied to single/multiple PDSCH scheduling, respectively. The user equipment can generate and transmit a type-2 HARQ-ACK codebook including HARQ-ACK information for single/multiple PDSCH scheduling (S2406). The type-2 HARQ-ACK codebook includes a first sub-codebook and can additionally include a second sub-codebook.

Here, the first sub-codebook includes TB-based HARQ-ACK information for single PDSCH scheduling. The TB-based HARQ-ACK information for multi-PDSCH scheduling can be included in the first sub-codebook or composed of the second sub-codebook based on the number of bundled HARQ-ACK bits. For example, if the number of PDSCH/bundling groups for multi-PDSCH scheduling is X or less (e.g., x=1), TB-based HARQ-ACK information for multi-PDSCH scheduling can be included in the first sub-codebook. On the other hand, when the number of PDSCH/bundling groups for multi-PDSCH scheduling exceeds X, the TB-based HARQ-ACK information for multi-PDSCH scheduling can be composed of the second sub-codebook. The second sub-codebook is connected after the first sub-codebook.

Fig. 25 is a diagram showing a configuration of a UE and a base station according to an embodiment of the present disclosure. In embodiments of the present disclosure, a UE may be implemented with various types of wireless communication devices or computing devices that are guaranteed to be portable and mobile. A UE may be referred to as a User Equipment (UE), a Station (STA), a mobile user (MS), etc. Further, in the embodiments of the present disclosure, the base station controls and manages cells (e.g., macro cells, femto cells, pico cells, etc.) corresponding to the service area, and performs functions of signal transmission, channel assignment, channel monitoring, self diagnosis, relay, etc. A base station may be referred to as a next generation node B (gNB) or an Access Point (AP).

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

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

Next, the communication module 120 may be an integrated module that performs wireless communication using a wireless communication network and performs wireless LAN access using a wireless LAN. To this end, the communication module 120 may include a plurality of Network Interface Cards (NICs) in internal or external form, such as cellular communication interface cards 121 and 122 and unlicensed band communication interface card 123. In the drawings, the communication module 120 is shown as a unitary integrated module, but unlike the drawings, each network interface card can be independently arranged according to a circuit configuration or use.

The cellular communication interface card 121 may transmit or receive a radio signal using at least 1 of the base station 200, an external device, and a server by using a mobile communication network, and provide a cellular communication service in a first frequency band based on an instruction from the processor 110. According to an embodiment, cellular communication interface card 121 may include at least 1 NIC module that uses a frequency band less than 6 GHz. At least 1 NIC module of the cellular communication interface card 121 may independently perform cellular communication using at least 1 of the base station 200, the external device, and the server according to cellular communication standards or protocols in a frequency band below 6GHz supported by the corresponding NIC module.

The cellular communication interface card 122 may transmit or receive a radio signal using at least 1 of the base station 200, an external device, and a server by using the mobile communication network, and provide a cellular communication service in the second frequency band based on an instruction from the processor 110. According to an embodiment, cellular communication interface card 122 may include at least 1 NIC module that uses a frequency band greater than 6 GHz. At least 1 NIC module of the cellular communication interface card 122 may independently utilize at least 1 of the base station 200, external devices, and servers for cellular communication according to cellular communication standards or protocols over the 6GHz band or more supported by the corresponding NIC module.

The unlicensed band communication interface card 123 transmits or receives radio signals using at least 1 of the base station 200, the external device, and the server by using a third frequency band that is an unlicensed band, and provides an unlicensed band communication service based on instructions from the processor 110. The unlicensed band communication interface card 123 may include at least 1 NIC module that uses unlicensed bands. For example, the unlicensed frequency band may be a 2.4GHz or 5GHz frequency band. At least 1 NIC module of the unlicensed band communication interface card 123 may independently or in association communicate wirelessly using at least 1 of the base station 200, external devices, and servers according to unlicensed band communication standards or protocols for the bands supported by the responsive NIC module.

The memory 130 stores a control program used in the UE 100 and various data thereof. Such a control program may include a prescribed program required to perform wireless communication using at least 1 of the base station 200, the external device, and the server.

Next, the user interface 140 includes various input/output devices provided in the UE 100. In other words, the user interface 140 may receive user input using various input devices, and the processor 110 may control the UE 100 based on the received user input. Further, the user interface 140 may perform output based on instructions from the processor 110 using various output devices.

Next, the display unit 150 outputs various images on the display screen. The display unit 150 may output various display objects, such as content executed by the processor 110 or a user interface, based on control instructions from the processor 110.

Further, the base station 200 according to the embodiments of the present disclosure may include a processor 210, a communication module 220, and a memory 230.

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

Next, the communication module 220 may be an integrated module that performs wireless communication using a wireless communication network and performs wireless LAN access using a wireless LAN. To this end, the communication module 120 may include a plurality of network interface cards in internal or external form, such as cellular communication interface cards 221 and 222 and unlicensed band communication interface card 223. In the drawings, the communication module 220 is shown as a unitary integrated module, but unlike the drawings, each network interface card can be independently arranged according to a circuit configuration or use.

The cellular communication interface card 221 may transmit or receive a radio signal using at least 1 of the UE100, an external device, and a server by using a mobile communication network, and provide a cellular communication service in a first frequency band based on an instruction from the processor 210. According to an embodiment, cellular communication interface card 221 may include at least 1 NIC module that uses a frequency band less than 6 GHz. At least 1 NIC module of the cellular communication interface card 221 may independently perform cellular communication using at least 1 of the UE100, external devices, and servers according to cellular communication standards or protocols in a frequency band below 6GHz supported by the corresponding NIC module.

The cellular communication interface card 222 may transmit or receive a radio signal using at least 1 of the UE100, an external device, and a server by using a mobile communication network, and provide a cellular communication service in a second frequency band based on an instruction from the processor 210. According to an embodiment, cellular communication interface card 222 may include at least 1 NIC module that uses a frequency band of 6GHz or more. At least 1 NIC module of the cellular communication interface card 222 may independently utilize at least 1 of the base station 100, external devices, and servers for cellular communication according to cellular communication standards or protocols over the 6GHz band or more supported by the corresponding NIC module.

The unlicensed band communication interface card 223 transmits or receives radio signals with at least 1 of the base station 100, external devices, and servers by using a third frequency band, which is an unlicensed band, and provides unlicensed band communication services based on instructions from the processor 210. The unlicensed band communication interface card 123 may include at least 1 NIC module that uses unlicensed bands. For example, the unlicensed frequency band may be a 2.4GHz or 5GHz frequency band. At least 1 NIC module of the unlicensed band communication interface card 123 may independently or in association communicate wirelessly using at least 1 of the UE100, external devices, and servers according to unlicensed band communication standards or protocols for the bands supported by the responsive NIC module.

Fig. 25 is a block diagram illustrating the UE 100 and the base station 200 according to an embodiment of the present disclosure, and separately illustrated blocks are elements of a logical division of a device. Thus, the above-described elements of the device may be mounted in a single chip or multiple chips, depending on the design of the device. Further, a part of the configuration of the UE 100, for example, the user interface 140, the display unit 150, etc., may be selectively provided in the UE 100. Further, if necessary, a user interface 140, a display unit 150, etc. may be additionally provided in the base station 200.

The foregoing description of the present disclosure is for the purpose of illustration, and it will be understood by those skilled in the art to which the present disclosure pertains that modifications of other specific forms may be readily achieved without changing the technical spirit or essential features of the present disclosure. Accordingly, it should be understood that the above-described embodiments are illustrative in all respects and not restrictive. For example, individual elements described as being of a single type may be implemented in a distributed fashion, and similarly elements described as being distributed may be implemented in a combination.

The scope of the present disclosure is indicated by the claims described below rather than the detailed description, and all changes or modifications that come within the meaning and range of equivalency of the claims are to be embraced within their scope.

The present invention can be applied to a wireless communication system. In particular, the present invention can be used in a communication method used in a wireless communication system and an apparatus thereof.

Claims

1. A user equipment for use in a wireless communication system, the user equipment comprising:

a communication module; and

a processor, said processor controlling said communication module,

wherein the processor is configured to:

receiving a Physical Downlink Control Channel (PDCCH) having the following information:

-timing information indicating one value in the K1-set { K1i } (i=1, 2.) for PDSCH-to-HARQ (hybrid automatic repeat and request) slot timing;

determining a time slot n-K1 for all K1 values in the K1-set when the time slot n is indicated by the timing information _i PDSCH candidates of (a); and

transmitting a semi-static HARQ-ACK codebook in the slot n based on the determined PDSCH candidates for each slot, and

when determining the PDSCH candidates, replacing the K1-set by a union of subsequent K-sets #i based on at least one entry in the TDRA table associated with a plurality of PDCCH-to-PDSCH slot timing K0 values,

-K-set #i: { K1 _i +d ₁ ,K1 _i +d ₂ ,…,K1 _i +d _N },

2. The user equipment of claim 1, wherein a subcarrier spacing (SCS) applied to a slot in which the PDCCH is transmitted is the same as the SCS applied to a slot in which the semi-static HARQ-ACK codebook is transmitted.

3. The user equipment of claim 1, wherein, with respect to the determined PDSCH candidates for each slot, a plurality of HARQ-ACK occasions are sequentially allocated to non-overlapping PDSCH candidates with reference to the PDSCH candidate having the earliest last symbol, and the semi-static HARQ-ACK codebook is configured based on the plurality of HARQ-ACK occasions.

4. The user equipment of claim 3, wherein the plurality of HARQ-ACK opportunities are allocated based on the PDSCH candidates of the last slot to which the PDSCH of each bundling group can be allocated based on each entry in the TDRA table when a time domain bundling is applied to the semi-static HARQ-ACK codebook.

5. The user equipment of claim 1, wherein the wireless communication system comprises a third generation partnership project (3 GPP) New Radio (NR) based wireless communication system.

6. A method for use by a user equipment in a wireless communication system, the method comprising:

-timing information indicating a value in the K1 set { K1i } (i=1, 2.) for PDSCH-to-HARQ (hybrid automatic repeat and request) slot timing;

transmitting a semi-static HARQ-ACK codebook in the slot n based on the determined PDSCH candidates for each slot, wherein

When determining the PDSCH candidates, replacing the K1-set by a union of the subsequent K-sets #i based on at least one entry in the TDRA table associated with a plurality of PDCCH-to-PDSCH slot timing K0 values,

-K-set#i：{K1 _i +d ₁ ,K1 _i +d ₂ ,…,K1 _i +d _N },

7. The method of claim 6, wherein a subcarrier spacing (SCS) applied to a slot in which the PDCCH is transmitted is the same as the SCS applied to a slot in which the semi-static HARQ-ACK codebook is transmitted.

8. The method of claim 6, wherein, with respect to the determined PDSCH candidates for each slot, a plurality of HARQ-ACK occasions are sequentially allocated to non-overlapping PDSCH candidates with reference to the PDSCH candidate having the earliest last symbol, and the semi-static HARQ-ACK codebook is configured based on the plurality of HARQ-ACK occasions.

9. The method of claim 8, wherein the plurality of HARQ-ACK opportunities are allocated based on the PDSCH candidates for the last slot to which the PDSCH of each bundling group can be allocated based on each entry in the TDRA table when a time domain bundling is applied to the semi-static HARQ-ACK codebook.

10. The method of claim 6, wherein the wireless communication system comprises a third generation partnership project (3 GPP) New Radio (NR) based wireless communication system.

11. A base station for use in a wireless communication system, the base station comprising:

a communication module; and

a processor, said processor controlling said communication module,

wherein the processor is further configured to:

transmitting a Physical Downlink Control Channel (PDCCH) having the following information:

receiving a semi-static HARQ-ACK codebook in said time slot n based on said determined PDSCH candidate for each time slot, and when said PDSCH candidate is determined, replacing said K1-set by a union of subsequent K-sets # i based on at least one entry in said TDRA table associated with a plurality of PDCCH-to-PDSCH slot timing K0 values,

-K-set #i: { K1 _i +d ₁ ,K1 _i +d ₂ ,…,K1 _i +d _N },

12. The base station of claim 11, wherein a subcarrier spacing (SCS) applied to a slot in which the PDCCH is transmitted is the same as the SCS applied to a slot in which the semi-static HARQ-ACK codebook is transmitted.

13. The base station of claim 11, wherein, with respect to the determined PDSCH candidates for each slot, a plurality of HARQ-ACK opportunities are sequentially allocated to non-overlapping PDSCH candidates with reference to the PDSCH candidate having the earliest last symbol, and the semi-static HARQ-ACK codebook is configured based on the plurality of HARQ-ACK opportunities.

14. The base station of claim 13, wherein the plurality of HARQ-ACK opportunities are allocated based on the PDSCH candidates for the last slot to which the PDSCH of each bundling group can be allocated based on each entry in the TDRA table when a time domain bundling is applied to the semi-static HARQ-ACK codebook.

15. The base station of claim 11, wherein the wireless communication system comprises a third generation partnership project (3 GPP) New Radio (NR) based wireless communication system.

16. A method for use by a base station in a wireless communication system, the method comprising:

based on the determined PDSCH candidates for each slot, a semi-static HARQ-ACK codebook is received in the slot n,

wherein when determining the PDSCH candidates, the K1-set is replaced by a union of subsequent K-sets #i based on at least one entry in the TDRA table associated with a plurality of PDCCH-to-PDSCH slot timing K0 values,

-K-set #i: { K1 _i +d ₁ ,K1 _i +d ₂ ,…,K1 _i +d _N },

17. The method of claim 16, wherein a subcarrier spacing (SCS) applied to a slot in which the PDCCH is transmitted is the same as the SCS applied to a slot in which the semi-static HARQ-ACK codebook is transmitted.

18. The method of claim 16, wherein, with respect to the determined PDSCH candidates for each slot, a plurality of HARQ-ACK occasions are sequentially allocated to non-overlapping PDSCH candidates with reference to the PDSCH candidate having the earliest last symbol, and the semi-static HARQ-ACK codebook is configured based on the plurality of HARQ-ACK occasions.

19. The method of claim 18, wherein the plurality of HARQ-ACK opportunities are allocated based on the PDSCH candidate for the last slot to which the PDSCH of each bundling group can be allocated based on each entry in the TDRA table when a time domain bundling is applied to the semi-static HARQ-ACK codebook.

20. The method of claim 16, wherein the wireless communication system comprises a third generation partnership project (3 GPP) New Radio (NR) based wireless communication system.