CN113678394A - Method and apparatus for transmitting and receiving HARQ-ACK feedback in a wireless communication system

Info

Abstract

Description

Claims

CN113678394A

Publication number: CN113678394A
Application number: CN202080026871.4A
Authority: CN
Inventors: 卢勋东; 郑义昌; 朴珍贤; 杨熙喆
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2019-04-09
Filing date: 2020-04-08
Publication date: 2021-11-19
Also published as: EP3874670A1; EP3874670A4; KR20200119175A

The present disclosure relates to a communication scheme and system for merging a fifth generation (5G) communication system supporting a higher data rate than a fourth generation (4G) system with internet of things (IoT) technology. The present disclosure is applicable to smart services based on 5G communication technologies and IoT related technologies (e.g., smart homes, smart buildings, smart cities, smart cars or networked cars, healthcare, digital education, retail, and security related services). An operating method of a terminal for receiving data from a plurality of Transmission and Reception Points (TRPs) participating in a non-coherent joint transmission is disclosed. The method includes receiving information on HARQ-ACK codebook configuration, and configuring and transmitting an HARQ-ACK codebook corresponding to a plurality of TRPs based on the received information.

Method and apparatus for transmitting and receiving HARQ-ACK feedback in a wireless communication system

Technical Field

The present disclosure relates generally to wireless communication systems, and more particularly, to a codebook configuration method and apparatus for hybrid automatic repeat request (HARQ-ACK) feedback for a terminal.

Background

In order to meet the increasing demand for wireless data traffic since the deployment of fourth generation (4G) communication systems, efforts have been made to develop improved fifth generation (5G) or quasi-5G communication systems. The 5G or quasi-5G communication system may also be referred to as a "super 4G network" or a "Long Term Evolution (LTE) system".

To achieve higher data rates, 5G communication systems will be implemented in the higher frequency (millimeter wave) band (e.g., 60GHz band). In order to reduce propagation loss of radio waves and increase transmission distance, beamforming, massive Multiple Input Multiple Output (MIMO), full-dimensional MIMO (FD-MIMO), array antenna, analog beamforming, and massive antenna techniques for a 5G communication system are under discussion.

Further, in the 5G communication system, system network improvements are being developed based on advanced small cells, cloud Radio Access Networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, coordinated multipoint (CoMP), receiving end interference cancellation, and the like. In the 5G system, hybrid Frequency Shift Keying (FSK) and Quadrature Amplitude Modulation (QAM) (FQAM) and Sliding Window Superposition Coding (SWSC) have been developed as Advanced Coding Modulation (ACM), and filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA) and Sparse Code Multiple Access (SCMA) have been developed as advanced access technologies.

The internet is now evolving into the internet of things (IoT) in which distributed entities (i.e., things) exchange and process information. Internet of everything (IoE) has also emerged as a combination of IoT technology and big data processing technology through connection with cloud servers. Because IoT implementations require technical elements such as "sensing technology," "wired/wireless communication and network infrastructure," "service interface technology," and "security technology," sensor networks, machine-to-machine (M2M) communication, Machine Type Communication (MTC), and the like have been studied. Such IoT environments may provide intelligent internet technology services that collect and analyze data generated between interconnected things. IoT may be applied in a variety of fields including smart homes, smart buildings, smart cities, smart cars or networked cars, smart grids, healthcare, smart appliances, and advanced medical services through the fusion and integration of existing Information Technology (IT) with various industrial applications.

Consistent with this, various attempts have been made to apply the 5G communication system to the IoT network. For example, techniques such as sensor network, MTC, and M2M communication may be implemented through beamforming, MIMO, and array antennas. The application of cloud RAN as the big data processing technology described above is also an example of the convergence between 5G technology and IoT technology.

A wireless communication system developed as a result of adopting the above-described technology is likely to be capable of providing various types of services, and a method for facilitating the provision of the services will be required.

Disclosure of Invention

Technical problem

Various types of services need to be supported in advanced wireless communication systems.

Solution to the problem

An aspect of the present disclosure is to provide a codebook configuration method and apparatus for HARQ-ACK feedback of a terminal in a wireless communication system.

According to an aspect of the present disclosure, a method performed by a terminal is provided. The method includes receiving information configuring feedback of acknowledgement/negative acknowledgement (ACK/NACK) as separate feedback or joint feedback; generating a first hybrid automatic repeat request acknowledgement (HARQ-ACK) codebook associated with a Physical Downlink Shared Channel (PDSCH) corresponding to a first control resource set (CORESET) having a first index value; generating a second HARQ-ACK codebook associated with a PDSCH corresponding to a second CORESET having a second index value; obtaining HARQ-ACK information bits by concatenating (concatenating) a second HARQ-ACK codebook after the first HARQ-ACK codebook, in case that the joint feedback is configured; and transmitting the HARQ-ACK information bits in a Physical Uplink Control Channel (PUCCH).

According to another aspect of the disclosure, a method performed by a base station is provided. The method includes transmitting information configuring feedback of acknowledgement/negative acknowledgement (ACK/NACK) as separate feedback or joint feedback to a terminal; and receiving hybrid automatic repeat request acknowledgement (HARQ-ACK) information bits from the terminal in a Physical Uplink Control Channel (PUCCH), wherein the HARQ-ACK information bits are obtained by concatenating a second HARQ-ACK codebook after a first HARQ-ACK codebook in case joint feedback is configured, wherein the first HARQ-ACK codebook is associated with a Physical Downlink Shared Channel (PDSCH) corresponding to a first control resource set (CORESET) having a first index value, and wherein the second HARQ-ACK codebook is associated with a PDSCH corresponding to a second CORESET having a second index value.

According to another aspect of the present disclosure, a terminal is provided. The terminal includes a transceiver configured to transmit and receive signals; and a controller configured to: receiving information configuring feedback of acknowledgement/negative acknowledgement (ACK/NACK) as separate feedback or joint feedback; generating a first hybrid automatic repeat request acknowledgement (HARQ-ACK) codebook associated with a Physical Downlink Shared Channel (PDSCH) corresponding to a first control resource set (CORESET) having a first index value; generating a second HARQ-ACK codebook associated with a PDSCH corresponding to a second CORESET having a second index value; under the condition that the joint feedback is configured, acquiring HARQ-ACK information bits by serially connecting a second HARQ-ACK codebook behind a first HARQ-ACK codebook; and transmitting the HARQ-ACK information bits in a Physical Uplink Control Channel (PUCCH).

According to another aspect of the present disclosure, a base station is provided. The base station includes a transceiver configured to transmit and receive signals; and a controller configured to: transmitting information configuring feedback of acknowledgement/negative acknowledgement (ACK/NACK) as separate feedback or joint feedback to a terminal, and receiving hybrid automatic repeat request acknowledgement (HARQ-ACK) information bits from the terminal in a Physical Uplink Control Channel (PUCCH), wherein the HARQ-ACK information bits are obtained by concatenating a second HARQ-ACK codebook after a first HARQ-ACK codebook in case of configuring the joint feedback, wherein the first HARQ-ACK codebook is associated with a Physical Downlink Shared Channel (PDSCH) corresponding to a first control resource set (CORESET) having a first index value, and wherein the second HARQ-ACK codebook is associated with a PDSCH corresponding to a second CORESET having a second index value.

Advantageous effects of the invention

According to embodiments of the present disclosure, various types of services may be efficiently supported in an advanced wireless communication system.

Drawings

The above and other aspects, features and advantages of particular embodiments of the present disclosure will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which:

FIG. 1 shows a time-frequency resource structure of an LTE, LTE-Advanced or NR system;

FIG. 2 illustrates a scalable frame structure according to an embodiment;

fig. 3 shows a scalable frame structure according to an embodiment;

fig. 4 shows a scalable frame structure according to an embodiment;

fig. 5 illustrates a bandwidth divided into two bandwidth parts (BWPs) configured for a terminal in a 5G communication system according to an embodiment;

fig. 6 illustrates a dynamic BWP configuration indication and change method according to an embodiment;

fig. 7 illustrates Physical Downlink Shared Channel (PDSCH) frequency domain resource allocation in accordance with an embodiment;

figure 8 illustrates PDSCH time domain resource allocation according to an embodiment;

FIG. 9 illustrates a time domain resource allocation based on data channel subcarrier spacing and control channel subcarrier spacing in accordance with an embodiment;

figure 10 illustrates PUCCH resource allocation for HARQ-ACK feedback according to an embodiment;

fig. 11 illustrates a coordinated transmission antenna configuration according to an embodiment;

figure 12 shows PDSCH and PUCCH resource allocations for coordinated transmission and a single PUCCH and multiple PUCCHs carrying a HARQ-ACK codebook corresponding to the PDSCH, in accordance with an embodiment;

fig. 13 illustrates a type 1HARQ-ACK codebook structure according to an embodiment, which is different according to whether slot-level bundling (HARQ-ACK slot bundling) is applied;

fig. 14 illustrates a method for configuring a HARQ-ACK codebook to be transmitted over multiple PUCCHs, according to an embodiment;

fig. 15 illustrates a method for configuring a HARQ-ACK codebook based on a condition whether a plurality of PUCCH resources overlap at a symbol level according to an embodiment;

fig. 16 illustrates a PUCCH resource configuration operation of a terminal according to an embodiment;

fig. 17 illustrates the operation of the terminal according to the embodiment:

fig. 18 illustrates a PUCCH resource configuration operation of a terminal according to an embodiment;

fig. 19 illustrates a method for identifying a PUCCH corresponding to a Physical Downlink Control Channel (PDCCH) and a PUCCH resource of each transmission and reception point (each TRP) scheduled by the PDCCH according to an embodiment;

fig. 20 shows a terminal according to an embodiment; and

fig. 21 shows a base station according to an embodiment.

Detailed Description

Various embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

Advantages and features of the present disclosure and methods of accomplishing the same may be understood more readily by reference to the following detailed description of the embodiments and the accompanying drawings. This disclosure may, however, be embodied in many different forms and should not be construed as limited to the particular embodiments set forth herein, but rather these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concept of the disclosure to those skilled in the art

Detailed descriptions of technical specifications well known in the art and directly irrelevant to the present disclosure may be omitted to avoid obscuring the subject matter of the present disclosure. Basically, unnecessary description is omitted in order to make the subject matter of the present disclosure clearer.

Similarly, some elements are enlarged, omitted, or simplified in the drawings, and in fact, may have sizes and/or shapes different from those shown in the drawings. Throughout the drawings, identical or equivalent parts are indicated by identical reference numerals.

Each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, implement the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer program instructions may also be stored in a non-transitory computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the non-transitory computer-readable memory produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

Further, various block diagrams may illustrate modules, segments, or portions of code comprising at least one or more executable instructions for performing the specified logical function(s). The functions of these blocks may be performed in a different order in several modifications. For example, two consecutive blocks may be executed substantially concurrently, or may be executed in reverse order depending on their functions.

According to embodiments of the present disclosure, the term "module" means, but is not limited to, a software or hardware component, such as a Field Programmable Gate Array (FPGA) or an Application Specific Integrated Circuit (ASIC), that performs certain tasks. A module may advantageously be configured to reside on the addressable storage medium and configured to execute on one or more processors. Accordingly, a module may include components, such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functionality of the components and modules may be combined into fewer components and modules or further separated into more components and modules. Further, the components and modules may be implemented such that they run one or more Central Processing Units (CPUs) in the device or secure multimedia card.

The operational principles of the present disclosure are described in detail with reference to the accompanying drawings.

Terms are defined herein in consideration of functions in the present disclosure, and the terms may vary according to the intention, use, and the like of a user or an operator. Therefore, it should be defined in light of the overall disclosure.

In the description, the term "Base Station (BS)" denotes an entity for allocating resources to a terminal and is intended to include at least one of a node B, an evolved node B (enb), a radio access unit, a base station controller, and a network node. The term "terminal" is intended to include User Equipment (UE), Mobile Stations (MS), cellular telephones, smart phones, computers, and multimedia systems with communication capabilities. However, the disclosure is not limited by these terms.

The present disclosure provides a technique for a terminal to receive broadcast information from a base station in a wireless communication system. The present disclosure is applicable to smart services based on 5G communication technologies and IoT related technologies (e.g., smart homes, smart buildings, smart cities, smart cars or networked cars, healthcare, digital education, retail, and security related services).

For ease of explanation, terms used in the following description to indicate broadcast information, network entities, communication coverage (coverage), state transitions (e.g., events), network entities, messages, and components of devices are provided. Accordingly, the present disclosure is not limited by the terms used in the following description, and may be replaced by other terms having equivalent meanings.

In the following description, the terms and definitions given in the third generation partnership project LTE (3GPP LTE) standard are used. However, the present disclosure is not limited by terms and definitions and may be applied to other standard communication systems.

Mobile communication systems have evolved into high-speed, high-quality packet data communication systems such as high-speed packet access (HSPA), LTE (or evolved universal terrestrial radio access (E-UTRA)) and LTE-Advanced (LTE-a) defined in 3GPP, High Rate Packet Data (HRPD), Ultra Mobile Broadband (UMB) defined in third generation partnership project-2 (3GPP2), and Institute of Electrical and Electronics Engineers (IEEE) defined and 802.16E, capable of providing data and multimedia services in addition to early voice-oriented services.

As a representative broadband wireless communication system, the LTE system uses Orthogonal Frequency Division Multiplexing (OFDM) in the downlink and single carrier frequency division multiple access (SC-FDMA) in the uplink. The term "Uplink (UL)" denotes a radio transmission path from a terminal (or UE or MS) to a base station, and the term "Downlink (DL)" denotes a radio transmission path from a base station to a terminal. Such a multiple access scheme is characterized in that time-frequency resources for transmitting user-specific data information and control information are allocated without overlapping each other (i.e., maintaining orthogonality) in order to distinguish the user-specific data information and control information.

As a next generation communication system after LTE, a 5G communication system should satisfy various demands for services by users and service providers. Services supported by 5G systems can be divided into three categories: enhanced mobile broadband (eMBB), large-scale machine type communication (mMTC), and ultra-reliable low-latency communication (URLLC).

The eMBBs are intended to provide exceptionally high data rates compared to the data rates supported by legacy LTE, LTE-A, and LTE-A Pro. For example, for each base station, the eMBB should increase the peak data rate to 20Gbps in the DL and 10Gbps in the UL. Meanwhile, the eMBB should increase the user perceived data rate. In order to meet these requirements, signal transmission/reception techniques including MIMO techniques should be improved. The data rate requirements of a 5G communication system can be met by using a wider frequency bandwidth than 20MHz in the frequency band of 3 to 6GHz or above 6GHz, instead of using the current LTE frequency band of 2 GHz.

mtc is intended to support application services for IoT. In order to effectively provide the mtc-based IoT application service, it is necessary to secure a large amount of access resources for terminals within a cell, improve terminal coverage and battery life, and reduce device manufacturing costs. Given the nature of IoT terminals attached to various sensors and devices to provide communication functions, IoT services should be designed to support a large number of terminals within a cell (e.g., 1000000 terminals per square kilometer). Depending on the nature of the IoT service, the mtc terminal may be located in a coverage hole (such as a basement of a building), which requires greater coverage than other services supported in a 5G communication system. Mtc terminals characterized by low price and difficulty in battery replacement should be designed to have a long battery life.

URLLC is directed to mission critical cellular-based communication services such as telerobotic and mechanical control, industrial automation, unmanned aerial vehicles, remote healthcare, and emergency alert services requiring ultra-low latency and ultra-high reliability. Therefore, URLLC service requires ultra-low latency and ultra-high reliability. For example, URLLC service should satisfy air interface delay below 0.5ms and packet error rate less than or equal to 10^-5The requirements of (1).To support URLLC services, a 5G system should support shorter Transmission Time Intervals (TTIs) than those of other services and allocate wide resources in the frequency band. Therefore, a 5G system should support a short TTI of URLLC (shorter than the TTIs of other services) and allocate extensive resources in the frequency band to guarantee the reliability of the communication link. Although these services may be classified as mtc, URLLC, and eMBB, the present disclosure is not limited by this classification.

The above-described services supported by the 5G system should be provided in a mixed manner within one framework. For resource management and control efficiency, services may be provided and controlled in a systematic manner rather than a service-specific manner.

Although the disclosed embodiments are directed to a particular system, such as LTE, LTE-a, LTE Pro, or NR, those skilled in the art will appreciate that these embodiments may be applied to other communication systems having similar technical background and channel format, with minor modifications, without departing from the spirit and scope of the present disclosure.

Fig. 1 shows a time-frequency resource structure of an LTE, LTE-a or NR system. In particular, fig. 1 shows a basic structure of a time-frequency resource region representing a radio resource region for transmitting data or control channels in an LTE, LTE-a or NR system employing Cyclic Prefix (CP) OFDM (CP-OFDM) or SC-FDMA waveforms.

Referring to fig. 1, the horizontal axis represents time and the vertical axis represents frequency. UL denotes a radio link for transmitting data or control signals from the terminal to the base station, and DL denotes a radio link for transmitting data or control signals from the base station to the terminal.

In LTE, LTE-A and 5G, the smallest transmission unit in the time domain is an OFDM symbol or SC-FDMA symbol, and N_symbThe individual symbols 1-05 form slots 1-15. In LTE and LTE-A, 2 slots (each slot is defined by N _symb7 symbols) form sub-frames 1-40. In 5G, two types of slots (i.e., slots and minislots (or non-slots)) may be supported. In 5G, for a slot, N_symbCan be set to 7 or 14 and for a minislot, N_symbCan be set to 1, 2, 3, 4, 5, 6 and 7One, the first step. In 5G, the length of the slot or mini-slot may vary with subcarrier spacing, unlike in LTE and LTE-a (the slot has a fixed length of 0.5ms, and the subframe has a fixed length of 1.0 ms).

In LTE and LTE-a, radio frames 1-35 are time units consisting of 10 subframes. In LTE and LTE-A, the subcarrier is the minimum transmission unit of 15kHz subcarrier spacing in the frequency domain, and N in total_BWThe (1 to 10) subcarriers constitute a system transmission bandwidth. In contrast, 5G is designed to have a flexible and scalable frame structure, as will be described later.

In the time-frequency domain, the basic resource units are Resource Elements (REs) 1-30 indicated by OFDM or SC-FDMA symbol indexes and subcarrier indexes. Resource Blocks (RBs) (or Physical RBs (PRBs)) 1-20 are represented by N in the time domain_symbOne consecutive OFDM or SC-FDMA symbol 1-05 and N in frequency domain_RBDefined by the number of consecutive subcarriers 1-25. Thus, one RB 1-20 is formed by N_symb x N_RBRE 1-30.

In LTE and LTE-a, data mapping is performed in RB units, and the eNB schedules UEs in RB pair (RB pair) units in a subframe. The number of SC-FDMA or OFDM symbols (N) is determined according to the length of CP added to each symbol to avoid inter-symbol interference (ISI)_symb),. For example, for normal CP, N_symbIs set to 7 and for extended CP, N_symbIs set to 6. In a system with a relatively long radio propagation distance, the extended CP may be preferred over the normal CP to maintain orthogonality between symbols.

For smooth communication between the base station and the terminal, the base station and the terminal should share information for OFDM communication, such as subcarrier spacing (SCS) and CP length.

Since the above-described LTE/LTE-a frame structure is designed in consideration of general voice/data communication, there is a limit to satisfying scalability requirements for 5G supporting various types of services. Therefore, a flexible frame structure needs to be designed for 5G in view of scalability requirements for various types of services.

Fig. 2 to 4 show scalable frame structures according to embodiments. In particular, fig. 2 to 4 show differently scaled frame structures, each having the necessary parameter sets including subcarrier spacing, CP length and slot length.

In its initial deployment, the 5G system may coexist with a legacy LTE/LTE-a system and operate in dual mode, in which the 5G system operates with the legacy LTE/LTE-a system. This may allow the 5G system to provide enhanced services with the assistance of legacy LTE/LTE-a systems to ensure stability. Therefore, the scalable frame structure of the 5G system should contain the LTE/LTE-a frame structure and its necessary parameters.

Fig. 2 shows a scalable frame structure according to an embodiment. Specifically, fig. 2 shows RBs at slots of a 5G frame that are identical in structure and necessary parameters to an LTE/LTE-a frame.

Referring to fig. 2, in a type a frame structure, a PRB consists of 14 symbols (constituting a slot spanning 1 ms) and 12 subcarriers, each having a carrier spacing of 15kHz, and 12 subcarriers spanning 180kHz (═ 12 × 15 kHz).

Fig. 3 shows a scalable frame structure according to an embodiment.

Referring to fig. 3, a PRB in a type B frame structure consists of 14 symbols (constituting a slot spanning 0.5 ms) and 12 subcarriers, each having a subcarrier spacing of 30kHz, the 12 subcarriers spanning 360kHz (═ 12 × 30 kHz). That is, the PRBs of the type B frame structure are twice the size of the PRBs of the type a frame structure in subcarrier spacing and half the size of the PRBs of the type a frame structure in symbol length.

Fig. 4 shows a scalable frame structure according to an embodiment.

Referring to fig. 4, a PRB in a type C frame structure consists of 14 symbols (constituting a slot spanning 0.25 ms) and 12 subcarriers, each having a 60kHz subcarrier spacing, the 12 subcarriers spanning 720kHz (═ 12 × 60 kHz). The type C frame-structured PRBs are four times as large as the type a frame-structured PRBs in subcarrier spacing, and the type C frame-structured PRBs are one-fourth as large as the type a frame-structured PRBs in symbol length.

As shown in fig. 2 to 4 and described above, the frame structure may be generalized to have an integer multiple relationship between the subcarrier spacing, the CP length, and the slot length constituting the necessary parameter set.

Independent of the type of the frame structure, a 1ms fixed length subframe may be defined as a reference time unit. In this case, the subframe consists of one slot in the type a frame structure, two slots in the type B frame structure, and four slots in the type C frame structure. However, the scalable frame structure is not limited to type A, B or C, and the subcarrier spacing may be changed, for example, to 120kHz and 240 kHz.

The above-described type of frame structure can be applied to various scenes. In view of cell size, the type a frame structure may be better than the type B frame structure and the type C frame structure in a relatively large cell because the cell size to be covered increases as the CP length increases. In view of the operating frequency band, the type C frame structure may be superior to the type a frame structure and the type B frame structure at a relatively high frequency because the phase noise recovery performance improves as the subcarrier spacing increases in the high frequency band. Type C frame structures may be preferred over type a and type B frame structures in view of services, because the supportability of ultra low delay, such as URLLC, improves with decreasing subframe length.

Several types of subframe structures may also be multiplexed in one system for system management.

In NR, a maximum of 250 RBs can be configured for a Component Carrier (CC) or a serving cell. In order to overcome excessive power consumption caused by a terminal receiving a signal using the entire serving cell bandwidth as in LTE, a base station may configure at least one BWP to the terminal so that the terminal may change a reception area in a cell.

In NR, the base station may configure an initial BWP as a bandwidth of a control resource set (CORESET) #0 (or common search space (CCS)) for the terminal via a Master Information Block (MIB). The base station may configure an initial BWP (i.e., a first BWP) of the terminal and transmit one or more BWP configuration information items, which may be indicated via Downlink Control Information (DCI), to the terminal via Radio Resource Control (RRC) signaling. The base station may transmit a BWP Identifier (ID) to the terminal via DCI to inform the terminal of a band to be used. The terminal may attempt to receive DCI in a default BWP if DCI is not received in the currently allocated BWP within a predetermined time period.

Fig. 5 illustrates a bandwidth divided into two BWPs configured for a terminal in a 5G communication system according to an embodiment.

Referring to FIG. 5, the UE bandwidth 5-00 is divided into two BWPs, BWP # 15-05 and BWP # 25-10. The base station may configure one or more BWPs for the terminal, each BWP being configured with information as shown in table 1 below.

[ TABLE 1 ]

The contents of table 1 are as follows:

configuration information 1: BWP Bandwidth (number of PRBs constituting BWP)

Configuration information 2: frequency location of BWP (offset from a reference point such as center frequency of CC, synchronization signal grid (raster), etc.)

Configuration information 3: parameter set (numerology) of BWP (subcarrier spacing, CP length, etc.)

-others

In addition to the configuration information in table 1, various BWP-related parameters may be configured for the terminal. The base station may send the configuration information to the terminal via higher layer signaling (e.g., RRC signaling). At least one BWP may be activated among one or more BWPs configured for the terminal. The information indicating whether the configured BWP is activated may be semi-statically transmitted from the base station to the terminal via RRC signaling or dynamically transmitted to the terminal via a Media Access Control (MAC) Control Element (CE) (MAC CE) or DCI.

In a 5G communication system, BWP may be configured for various purposes.

For example, a terminal may be configured with BWP when the bandwidth supported by the terminal is narrower than the system bandwidth. For example, the terminal may be configured with a frequency location of BWP (configuration information 1 in table 1) such that the terminal transmits/receives data at the corresponding frequency location.

As another example, the base station may configure multiple BWPs for the terminal to support different sets of parameters. For example, to support data communication using subcarrier spacings of 15kHz and 30kHz, a terminal may be configured with a subcarrier spacing of 15kHz in one BWP and a subcarrier spacing of 30kHz in another BWP. The BWP may be Frequency Division Multiplexed (FDM), and if data needs to be transmitted/received using a specific subcarrier spacing, the BWP may be a BWP configured with the specific subcarrier spacing.

As another example, the base station may configure the terminals with BWPs of different bandwidths in order to reduce power consumption of the terminals. For example, if a terminal supports a very wide bandwidth (e.g., 100MHz), the terminal may transmit data via the corresponding bandwidth, which may result in very high power consumption. In particular, when the terminal unnecessarily monitors a 100MHz wide band for the DL control channel without traffic, it is very inefficient from the viewpoint of power consumption. To reduce the power consumption of the terminal, the base station may configure the terminal with a relatively narrow bandwidth BWP (e.g., 20MHz BWP). The terminal may monitor the BWP of 20MHz without traffic and, if there is traffic to send or receive, transmit data via the BWP of 100MHz according to instructions from the base station.

Fig. 6 illustrates a dynamic BWP configuration indication and change method according to an embodiment.

Referring to fig. 6, the base station may configure one or more BWPs for the terminal and inform the terminal of the bandwidth, frequency location, and parameter set of each BWP, as described above with reference to table 1. The terminal may be configured with two BWPs in the UE bandwidth, BWP #16-05 and BWP # 26-10. One or more of the configured BWPs may be activated. In fig. 6, as an example, one BWP is activated.

More specifically, in fig. 6, BWP #16-05 is activated in slot # 06-25 in the configured BWP, so that the terminal can monitor the PDCCH in control region # 16-45 configured in BWP #16-05 and transmit/receive data 6-55 in BWP # 16-05. The activated BWP may determine a control region where the terminal monitors the PDCCH, i.e., a PDCCH monitoring bandwidth.

The base station may also transmit an indicator for changing the BWP configuration to the terminal. Here, changing the BWP configuration may be understood as activating a specific BWP (e.g., switching the activated BWP from BWP a to BWP B). The base station may transmit a configuration switching indicator to the terminal in a predetermined time slot, and the terminal may identify BWP to be activated at a predetermined time based on configuration information in the configuration switching indicator. Thereafter, the terminal may perform PDCCH monitoring in the control region determined by the newly activated BWP from a predetermined time.

The base station may transmit a configuration switch indicator for switching the activated BWP from BWP #16-05 to BWP #6-10 in slot # 16-30 to the terminal. Upon receiving the indicator, the terminal may activate BWP #26-10 based on information included in the indicator. BWP handover may require a transition time 6-20 that determines the time for which the handover is activated BWP. In fig. 6, transition time 6-20 occupies the duration remaining after receiving configuration switch indicator 6-15 in one slot. During transition time 6-20, data 6-55 is not transmitted/received, which allows BWP #26-10 to be activated in slot # 26-35 for the terminal to transmit/receive control channel 6-50 and data 6-55 in the corresponding BWP.

The base station may pre-configure one or more BWPs for the terminal via higher layer signaling (e.g., RRC signaling) and activate one of the pre-configured BWPs by sending a configuration switch indicator 6-15 to the terminal indicating the BWP to be activated. E.g. log₂An N-bit indicator may be used to indicate one of N preconfigured BWPs.

Table 2 shows values of a 2-bit indicator indicating BWP configuration information.

[ TABLE 2 ]

The configuration switch indicator 6-15 for switching activated BWP may be transmitted from the base station to the terminal via MAC CE signaling or L1 signaling (e.g., common DCI, group common DCI, and UE-specific DCI).

The point in time at which BWP is activated based on the configuration switch indicator 6-15 may be determined by using a predetermined value, e.g., N (≧ 1) slots after the slot in which the configuration switch indicator is received, or may be configured via higher layer signaling from the base station to the terminal, or indicated by information included in the configuration switch indicator 6-15. Upon receiving the configuration switch indicator 6-15, the terminal may apply the changed configuration at the time point determined by the above-described method.

In addition to the frequency domain candidate resource allocation method based on the BWP indication, NR employs a fine frequency domain resource allocation (FD-RA) method.

Fig. 7 illustrates PDSCH frequency domain resource allocation according to an embodiment. In particular, fig. 7 shows three FD-RA methods (i.e., type 07-00, type 17-05, and dynamic switching 7-10) in NR that can be configured via higher layer signaling.

Referring to fig. 7, when the terminal is configured to use only resource type 0 via higher layer signaling, DCI allocating PDSCH resources to the terminal may include DCI consisting of N, as shown by reference numerals 7-00_RBGBits of the bit composition fig. 7-15. N is a radical of_RBGIndicates the number of RB groups (RBGs) determined based on the BWP Size (indicated by the BWP indicator and the higher layer parameter RBG-Size), as shown in table 3 below, and the RBGs in which the corresponding bits are set to 1 in the bit map are used for data transmission.

[ TABLE 3 ]

When the terminal is configured to use only resource type 1 via higher layer signaling, DCI allocating PDSCH resources to the terminal may include DCI as shown by reference numerals 7-05

FD-RA information represented by one bit. The base station may configure the starting VRB 7-20 and the length 7-25 of the frequency domain resources that are continuously allocated from the starting VRB 7-20 using the FD-RA information.

When the terminal is configured to simultaneously use resource type 0 and resource type 1 (i.e., dynamic handover), DCI allocating PDSCH resources to the terminal may include FD-RA information represented by a bit width of a maximum value of 7-35 between a payload for configuring resource type 0 (i.e., bit map 7-15) and a payload for configuring resource type 1 (i.e., start VRB 7-20 and length 7-25), as shown by reference numerals 7-10. In this case, the Most Significant Bit (MSB)7-30 followed by FD-RA information in DCI is set to 0 to indicate the use of resource type 0 and set to 1 to indicate the use of resource type 1.

Fig. 8 illustrates PDSCH time domain resource allocation according to an embodiment.

Referring to fig. 8, a base station may indicate a time domain position of a PDSCH resource having an OFDM symbol start position 8-00 and a length 8-05 in a slot 8-10By data and control channel subcarrier spacing (μ) configured via higher layer signaling_PDSCH，μ_PDCCH) Scheduling offset (K)₀) And DCI to dynamically indicate.

Fig. 9 illustrates a time domain resource allocation based on data channel subcarrier spacing and control channel subcarrier spacing in accordance with an embodiment.

Referring to fig. 9, when the data channel subcarrier spacing and the control channel subcarrier spacing are equal to each other (i.e., μ;)_PDSCH＝μ_PDCCH) In time, as shown by reference numerals 9-00, the slot numbers of the data information and the control information are identical to each other, which allows the base station and the terminal to recognize that the scheduling offset (scheduling offset) is at a predetermined slot offset K₀And (4) occurs. However, when the data channel subcarrier spacing and the control channel subcarrier spacing are different from each other (i.e., μ;)_PDSCH≠μ_PDCCH) The slot numbers of the data information and the control information are different from each other, which allows the base station and the terminal to recognize that the scheduling offset is at a predetermined slot offset K based on the PDCCH subcarrier spacing₀And (4) occurs.

In NR, as listed in table 4, various DCI formats may be defined for different purposes, thereby improving control channel reception efficiency of a terminal.

[ TABLE 4 ]

The base station may use DCI format 1_0 or DCI format 1_1 for PDSCH scheduling in the cell.

When transmitted with a Cyclic Redundancy Check (CRC) scrambled by a cell radio network temporary identifier (C-RNTI), a configured scheduling RNTI (SC-RNTI), or a modulation and coding scheme cell RNTI (MCS-C-RNTI), DCI format 1_1 includes at least the following information:

identifier of DCI format (1 bit): a 1-bit DCI format indicator always set to 1.

Frequency domain resource allocation (

Bits): indication of frequency domain resource allocation, wherein

Indicating the size of the active DL BWP when DCI format 1_0 is monitored in the UE-specific search space, and the size of the initial DL BWP for any other case.

Time domain resource allocation (4 bits): an indication of a time domain resource allocation.

VRB-to-PRB mapping (1 bit): an indication that the VRP-to-PRB mapping for non-interleaving is set to 0 and the VRP-to-PRB mapping for interleaving is set to 1.

Modulation and coding scheme (5 bits): indication of modulation order and coding rate for PDSCH transmission.

New data indicator (1 bit): an indication of whether the PDSCH is an initial transmission or a retransmission is flipped (toggle).

Redundancy version (2 bits): an indication of a redundancy version for a PDSCH transmission.

HARQ process number (4 bits): indication of HARQ process number for PDSCH transmission.

DL allocation index (2 bits): a Downlink Assignment Index (DAI) indicator.

Transmit Power Control (TPC) command (2 bits) for the scheduled PUCCH: PUCCH power control indicator.

PUCCH resource indicator (3 bits): an indication of one of eight resources configured via higher layer signaling.

PDSCH-to-HARQ feedback timing indicator (3 bits): an indication of one of eight feedback timing offsets configured via higher layer signaling.

When transmitted together with a CRC scrambled by C-RNTI, SC-RNTI or MCS-C-RNTI, DCI format 1_1 includes at least the following information:

identifier of DCI format (1 bit): a 1-bit DCI format indicator that is always set to 1.

Carrier indicator (0 or 3 bits): carries an indication of the CC (or cell) of the PDSCH scheduled by the corresponding DCI.

Bandwidth part indicator (0 or 1 or 2 bits): carries an indication of BWP of PDSCH scheduled by the corresponding DCI.

Frequency domain resource allocation (frequency domain resource allocation determines payload): has the advantages of

Of the frequency domain resource allocation of, wherein

Indicating the size of the active DL BWP.

VRB-to-PRB mapping (0 or 1 bit): an indication that the VRP-to-PRB mapping for non-interleaving is set to 0 and the VRP-to-PRB mapping for interleaving is set to 1. If the frequency domain resource allocation is set to resource type 0, then it is 0 bits.

PRB bundling size indicator (0 or 1 bit): a 0 bit when the higher layer parameter prb-BundlingType is not configured or set to "static" and a 1 bit indication when the higher layer parameter prb-BundlingType is set to "dynamic".

Rate matching indicator (0, 1 or 2 bits): an indication of a rate matching pattern.

Zero Power (ZP) channel state information reference signal (CSI-RS) trigger (0 or 1 or 2 bits): triggering an indicator of aperiodic ZP CSI-RS.

For transport block 1:

For transport block 2:

DL allocation index (0 or 2 or 4 bits): a DAI indicator.

TPC command for scheduled PUCCH (2 bits): PUCCH power control indicator.

Antenna port (4 or 5 or 6 bits): an indication of a demodulation reference signal (DMRS) port and a Code Division Multiplexing (CDM) group with data.

Transmit configuration indication (0 or 3 bits): a TCI indicator.

Sounding Reference Signal (SRS) request (2 or 3 bits): an SRS transmission request indicator.

Code Block Group (CBG) transfer information (0 or 2 or 4 or 6 or 8 bits): an indication of whether or not a group of code blocks is transmitted on the scheduled PDSCH. When the corresponding CBG is not transmitted, it is 0 bit, and when the corresponding CBG is transmitted, it is 1 bit.

CBG flush out information (0 or 1 bit): an indication of whether the previous CBG was contaminated (con), and if retransmitted, a 0 bit indicates that it is likely to be contaminated, and a 1 bit indicates that it is being used (i.e., is combinable).

DMRS sequence initialization (0 or 1 bit): DMRS scrambling ID selection indicator.

In a corresponding cell, a terminal may receive DCI of up to 4 different sizes for each slot. In a corresponding cell, a terminal may receive DCI scrambled by C-RNTI of up to 3 different sizes for each slot.

Figure 10 illustrates PUCCH resource allocation for HARQ-ACK feedback according to an embodiment.

Referring to fig. 10, a PDSCH 10-05 carrying DL data is scheduled by a DCI of a PDCCH 10-00, information on a slot to which HARQ-ACK feedback corresponding to the PDSCH is mapped, and a PUCCH 10-10 to which HARQ-ACK feedback information is mapped. The slot interval between HARQ-ACK feedbacks corresponding to the PDSCH carrying DL data is identified by a PDSCH-to-HARQ feedback timing indicator indicating one of eight feedback timing offsets. A PUCCH resource including a type of PUCCH to which HARQ-ACK feedback information is mapped, a starting symbol position, and the number of mapped symbols is identified by a PUCCH resource indicator indicating one of eight resources configured via higher layer signaling.

The terminal may bundle HARQ-ACK feedback bits, and the bundled HARQ feedback bits to be transmitted to the base station may be referred to as a HARQ-ACK codebook. The base station may configure a type 1HARQ-ACK codebook for the terminal to transmit HARQ-ACK feedback bits corresponding to a PDSCH transmitted at a slot position of a predetermined timing. By using the counter DAI or the total DAI, the base station may configure a type 2HARQ-ACK codebook for the terminal to manage and transmit HARQ-ACK feedback bits corresponding to the actually transmitted PDSCH.

A terminal configured with the type 1HARQ-ACK codebook may determine feedback bits to be transmitted based on a table containing information on slots, starting symbols, and the number or length of symbols to which a PDSCH is mapped, and a K1 candidate value as HARQ-ACK feedback timing information of HARQ corresponding to the PDSCH. The table containing information on the slot, the starting symbol, and the number or length of symbols to which the PDSCH is mapped may be configured via higher layer signaling or set as a default table. The K1 candidate may be set to a default value (e.g., {1, 2, 3, 4, 5, 6, 7, 8}), or configured via higher layer signaling.

The serving cell c (M) may be calculated by the steps of [ pseudo code 1 ] as follows_A,C) Candidate PDSCH receiver opportunity (occase) set in (1).

[ pseudocode 1 start ]

-step 1: initialize j to 0, M_A,CIs initialized to an empty set, anThe HARQ-ACK transmission timing index (k) is initialized to 0.

-step 2: r is set to a row set of a table containing information on a slot to which the PDSCH is mapped, a starting symbol, and the number or length of symbols. If a symbol to which the PDSCH represented by each row of R is mapped is configured as a UL symbol, the corresponding row is deleted from R.

-step 3-1: if a terminal can receive a unicast PDSCH in a slot, and if R is not an empty set, k is added to the set M_A,CIn (1).

-step 3-2: counting the maximum number of PDSCHs that can be mapped to different symbols in R, increasing j by 1 until the end of counting, and adding j to M if the terminal can receive more than one PDSCH in a slot_A,CIn (1).

-step 4: k is incremented by 1 and the process starts again at step 2.

[ pseudocode 1 end ]

For M determined based on [ pseudo-code 1 ] may be determined by the following [ pseudo-code 2 ] steps_A,CHARQ-ACK feedback bits of (1).

[ pseudo-code 2 Start ]

-step 1: the HARQ-ACK receiver opportunity index (m) is initialized to 0 and the HARQ-ACK feedback bit index j is initialized to 0.

-step 2-1: if the terminal receives an indication of CBG-based PDSCH transmission and reception through at most 2 codewords of 1 PDSCH without HARQ-ACK bundling of the codewords or through higher layer signaling, j is increased by 1 to configure HARQ-ACK feedback bits for each codeword.

-step 2-2: each code HARQ-ACK feedback bit is configured by a binary AND (AND) operation if the terminal receives an indication of HARQ-ACK bundling of codewords AND reception of at most 2 codewords in the PDSCH via higher layer signaling.

-step 2-3: if the terminal receives an indication of CBG-based PDSCH transmission and reception of at most 2 codewords in the PDSCH via higher layer signaling, j is increased by 1 to configure HARQ-ACK feedback bits corresponding in number to CBGs.

-step 2-4: if the terminal receives an indication of CBG-based PDSCH transmission and reception of at most 2 codewords in the PDSCH via higher layer signaling, j is increased by 1 to configure HARQ-ACK feedback corresponding in number to CBG per codeword.

-step 2-5: setting HARQ-ACK feedback bits for the codewords if the terminal receives an indication that there is no CBG-based PDSCH transmission and an indication that at most 2 codewords are received in the PDSCH.

-step 3: m is incremented by 1 and the process starts again at step 2-1.

[ pseudocode 2 end ]

When the terminal is configured with the type 2HARQ-ACK codebook, feedback bits to be transmitted are determined based on a K1 candidate value as HARQ-ACK feedback timing information for the PDSCH and a counter DAI or a total DAI for managing HARQ-ACK feedback bits corresponding to the PDSCH. The K1 candidate value as HARQ-ACK feedback timing information for PDSCH forms a set of default values and values specified via higher layer signaling. For example, the default value may be the

set

1, 2, 3, 4, 5, 6, 7, 8.

Assume that DCI format 1_0 of scheduling PDSCH or counter DAI (or C-DAI) of DCI format 1_1 in the serving cell at PDCCH monitoring timing (m) is

And the total DAI (or T-DAI) of DCI format 1_0 or DCI format 1_1 scheduling PDSCH at PDSCH monitoring timing (m) is

The type 2HARQ-ACK codebook may be configured by the following [ pseudo code 3 ] step.

[ pseudo code 3 Start ]

-step 1: initializing serving cell index (c) to 0, PDCCH monitoring timing (m) to 0, j to 0, DAI comparison index V_tempAnd V_temp2Initialized to 0 and set of HARQ-ACK feedback bits (V)_S) Initialized to an empty set.

-step 2: excluding the serving cell from the set of serving cells if the PDCCH monitoring timing (m) precedes the DL BWP handover of the serving cell c, and if the DL BWP handover is not triggered by the DCI format 1_1 of the PDCCH monitoring timing (m).

-step 3-1: when a PDSCH scheduled by a PDCCH exists in a serving cell c at a PDCCH monitoring timing (m), if

Less than or equal to V_tempThen j is increased by 1 and will

Is set as V_temp. If it is not

For an empty set, it will

Is set as V_temp2(ii) a And if

If not, will

Set to Vtemp 2.

-step 3-2: if there is a PDSCH scheduled by the PDCCH at the PDCCH monitoring timing (m) in the serving cell c, and if the terminal receives no indication of HARQ-ACK bundling for the codeword via higher layer signaling and receives an indication of at most 2 codewords received in the PDSCH within at least one DL BWP of at least one serving cell, j is increased by 1 and HARQ-ACK feedback bits for each codeword are configured.

-step 3-3: if there is a PDSCH scheduled by PDCCH at PDCCH monitoring timing (m) in serving cell c AND if the terminal receives HARQ-ACK bundling of codewords via higher layer signaling AND an indication of at most 2 codewords in PDSCH within at least one DL BWP of at least one serving cell, each code HARQ-ACK feedback bit is configured by a binary AND operation.

-step 3-4: if there is a PDSCH scheduled by the PDCCH at the PDCCH monitoring timing (m) in the serving cell c, and the terminal does not receive an indication that at most 2 codewords are received in the PDSCH, HARQ-ACK feedback bits of the codewords are configured.

-step 4: c is incremented by 1 and the process starts again at step 2.

-step 5: m is incremented by 1 and the process starts again at step 2.

-step 6: if V_temp2Less than V_tempJ is increased by 1.

-step 7-1: setting a total number of HARQ-ACK feedback bits to 2 · (4 · j + V) if the terminal does not receive an indication of HARQ-ACK bundling for the codeword via higher layer signaling and receives an indication of reception of at most 2 codewords in the PDSCH within at least one DL BWP of at least one serving cell_temp2)。

-step 7-2: setting a total number of HARQ-ACK feedback bits to 4 · j + V if the terminal receives an indication of HARQ-ACK bundling for a codeword via higher layer signaling and does not receive an indication of receipt of at most 2 codewords in the PDSCH_temp2。

-step 8: the HARQ-ACK feedback bits that are not determined in steps 3-1, 3-2, 3-3, and 3-4 are set to NACK.

[ pseudocode 3 end ]

Based on the above-described DCI structure and HARQ-ACK codebook determination process, the HARQ-ACK codebook introduced in release 15 is directed to a case where a single HARQ-ACK codebook is transmitted in a specific slot to correspond to a PDSCH transmitted at a single transmission timing, which means that it is necessary to additionally specify coordinated transmission for a PDSCH requiring transmission of multiple HARQ-ACK codebooks to correspond to multiple timings. For example, the HARQ-ACK codebook determination method described above for determining the number of bits of the HARQ-ACK codebook corresponding to one PUCCH and HARQ-ACK codebook information should be extended in order to determine the HARQ-ACK codebook for two or more PUCCHs.

According to the embodiment, the method for designing the HARQ-ACK feedback bits can effectively determine the HARQ-ACK codebook for a plurality of PUCCHs, and therefore coordinated transmission efficiency is improved.

The method is applicable to both Frequency Division Duplex (FDD) and Time Division Duplex (TDD) systems.

Here, the phrase "higher layer signaling" indicates a signal transmission method for transmission from a base station to a terminal via a physical layer DL data channel or from a terminal to a base station via a physical layer UL data channel, and may also be referred to as RRC signaling, Packet Data Convergence Protocol (PDCP) signaling, or MAC CE signaling.

In practical applications, the term "coordinated TRP" may be replaced by the terms "coordinated panel", "coordinated beam", etc.

Phrases such as "for non-coherent joint transmission (NC-JT)" and "when NC-JT is applied" are used for convenience of explanation and may be interpreted differently according to circumstances, such as "when a terminal simultaneously receives one or more PDSCHs in BWP", "when a terminal indicates simultaneous reception of PDSCHs based on two or more TCIs in BWP", and "when a PDSCH received by a terminal is associated with one or more DMRS port groups".

A terminal may receive information from a plurality of TRPs having various channel qualities in a coordinated transmission environment, and a TRP having the best channel quality among the plurality of TRPs may be designated as a serving TRP for providing important control information, and the other TRPs are designated as a coordinating TRP.

Example 1:type 1HARQ-ACK codebook payload reduction for NC-JT

The 5G wireless communication system may provide a variety of services including ultra-low latency and high connection density services and high data rate services. In a wireless communication network having a plurality of cells, TRPs or beams, coordinated transmission of the cells, TRPs and/or beams may be used to meet various service requirements in order to increase the signal strength received by a terminal and to effectively control inter-cell, TRP and/or inter-beam interference.

Joint Transmission (JT) is a technique for coordinating transmissions and can use different cells, TRPs, and/or beams to increase the received signal strength at a terminal. Since channel characteristics between the terminal and the cell, TRP and/or beam are different from each other, different precoding, MCS and resource allocation schemes are applied to the link between the terminal and the cell, TRP and/or beam. For NC-JT supporting non-coherent precoding between cells, TRPs and/or beams, DL transmission information should be configured for each cell, TRP and/or beam.

Fig. 11 illustrates a coordinated transmission antenna configuration according to an embodiment. Specifically, fig. 11 shows a case where radio resources are allocated to each TRP according to the JT scheme and conditions.

Referring to fig. 11, cases 11-00 use coherent JT (C-JT) that supports coherent precoding between cells, TRPs, and/or beams. In C-JT, TRP A11-05 and TRP B11-10 transmit the same data (i.e., PDSCH), and multiple TRPs perform joint precoding. In this way, the TRP A11-05 and TRP B11-10 may transmit the same DMRS port (e.g., both TRPs transmit DMRS ports A and B) for use by the terminal 11-15 in receiving the same PDSCH. In this case, the terminals 11-15 may receive DCI for receiving the PDSCH demodulated by DMRS ports a and B.

In cases 11-20, NC-JT is used. In NC-JT, different PDSCHs are transmitted in a cell/TRP and/or beam, and precoding may be applied to each PDSCH. In this way, the TRP A11-25 and TRP B11-30 may transmit different DMRS ports (e.g., DMRS port A at TRP A and DMRS port B at TRP B) that the terminals 11-35 have available for use in receiving different PDSCHs. In this case, the terminals 11-35 may receive two types of DCI for receiving PDSCH a modulated by DMRS port a and PDSCH B modulated by DMRS port B.

Fig. 12 shows PDSCH and PUCCH resource allocation for coordinated transmission and a single PUCCH and multiple PUCCHs carrying a HARQ-ACK codebook corresponding to the PDSCH, according to an embodiment.

Referring to fig. 12, when NC-JT is applied, HARQ-ACK codebooks corresponding to different PDSCHs transmitted in respective cells, TRPs, and/or beams are transmitted to a base station through a single PUCCH or multiple PUCCHs.

When the HARQ-ACK codebook is transmitted through a single PUCCH as denoted by reference numerals 12-00, the terminal may generate a single HARQ-ACK codebook having HARQ-ACK feedback bits corresponding to different PDSCHs 12-05, 12-10, and 12-15 transmitted to a TRP (e.g., a serving TRP for the terminal to use in receiving the single PDSCH) in different cells, TRPs, and/or beams, and transmit the HARQ-ACK codebook through the single PUCCH 12-20.

When the HARQ-ACK codebook is transmitted through a plurality of PUCCHs as denoted by reference numerals 12-25, the terminal may configure HARQ-ACK codebooks corresponding to different PDSCHs 12-30, 12-35, and 12-40 transmitted in different cells, TRPs, and/or beams, and transmit separate (individual) HARQ-ACK codebooks to the TRPs, which have transmitted the corresponding PDSCHs, via the PUCCHs 12-55 and 12-60 mapped on the PUCCH resources, which are indicated by the DCI carried in the PDCCHs 12-45 and 12-50. The terminal may also configure a HARQ-ACK codebook having HARQ-ACK feedback bits corresponding to PDSCHs 12-30, 12-35, and 12-40 transmitted in different cells, TRPs, and/or beams, and transmit the HARQ-ACK codebook to a TRP, which has transmitted the PDSCH, via a plurality of PDCCHs 12-55 and 12-60 mapped onto PUCCH resources (indicated by DCIs 12-45 and 12-50).

When a terminal configures an HARQ-ACK codebook having HARQ-ACK feedback bits corresponding to a PDSCH transmitted in different cells, TRPs, and/or beams, and transmits the HARQ-ACK codebook via a single PUCCH, the increased number of bits constituting the HARQ-ACK codebook may cause a decrease in PUCCH coverage, reducing reception performance of a base station. Specifically, when the terminal receives the indication of the type 1HARQ-ACK codebook configuration, the terminal transmits HARQ-ACK feedback bits to the largest PDSCH in the slot at a predetermined timing, regardless of whether there is an actual PDSCH transmission, and linearly increases the number of HARQ-ACK codebook bits in proportion to the number of TRPs.

The following embodiments are directed to methods of reducing and indicating the number of HARQ-ACK codebook bits when a terminal receives an indication of a type 1HARQ-ACK codebook configuration and applies NC-JT.

Example 1-1:method for only supporting PDSCH mapping type A

In NC-JT, only PDSCH mapping type a is supported for PDSCH transmitted in different cells, TRPs and/or beams, which is informed to the terminal via higher layer configuration. In order to support only PDSCH mapping type a, the number of PDSCHs allowed to be scheduled in a range of non-overlapping symbols (define) per slot is limited to 1. Therefore, when the terminal determines the type 1HARQ-ACK codebook feedback bit width, the maximum number of PDSCHs allowed to be transmitted via each TRP at a slot position for NC-JT may always be calculated as 1. This reduces the HARQ-ACK feedback bit width for the slot of NC-JT.

The HARQ-ACK feedback bits may be determined as described below. For example, the above [ pseudo code 1 ] may be replaced by [ pseudo code 4 ]. The serving cell c (M) may be calculated by the steps of [ pseudo code 4 ] as follows_A,C) A set of candidate PDSCH receivers.

[ pseudo-code 4 Start ]

-step 1: initialize j to 0, M_A,CAn empty set is initialized and the HARQ-ACK transmission timing index (k) is initialized to 0.

-step 2-1: r is set to a row set of a table containing information on a slot to which the PDSCH is mapped, a starting symbol, and the number or length of symbols. If a symbol to which the PDSCH represented by each row of R is mapped is configured as a UL symbol, the corresponding row is deleted from R.

-step 2-2: when NC-JT is applied to a slot corresponding to k and only PDSCH mapping type a is supported according to a higher layer configuration when NC-JT is applied, if each row of R indicates PDSCH mapping type B, the corresponding row is deleted from R.

-step 3-2: if the terminal can receive more than one PDSCH in a slot, the maximum number of PDSCHs that can be mapped to different symbols in R is counted, j is increased by 1 until the corresponding number is reached, and j is added to M_A,CIn (1).

-step 4: k is incremented by 1 and the process starts again at step 2.

[ pseudocode 4 end ]

Table 5 below provides an example of information on a slot, a starting symbol, and the number or length of symbols to which the PDSCH is mapped.

[ TABLE 5 ]

According to table 5, when both PDSCH mapping types a and B are supported, a maximum of 3 PDSCHs may be mapped to one slot, and when only PDSCH mapping type a is supported, a maximum of 1 PDSCH may be mapped to one slot.

Although the method disclosed in embodiment 1-1 is advantageous in reducing the HARQ-ACK feedback bit width in a slot for NC-JT, it may be disadvantageous in reducing the degree of freedom of PDSCH mapping due to the limited symbol position and the number of allocable symbols within the slot (as a result of the limitation on the PDSCH mapping type of NC-JT). The embodiments described below are directed to a method of reducing the type 1HARQ-ACK codebook bit width without compromising the degree of freedom of PDSCH mapping.

Examples 1 to 2:method for supporting HARQ-ACK time slot level bundling

Each TRP may not schedule two or more PDSCHs in one slot and may transmit an indication of a type 1HARQ-ACK codebook configuration for a terminal to generate a type 1HARQ-ACK codebook having a bit width reduced by bundling HARQ-ACK feedback bits corresponding to PDSCHs transmitted in slots for NC-JT. When receiving the indication of the type 1HARQ-ACK codebook configuration, the HARQ-ACK bit width is determined by the maximum number of PDSCHs that can be transmitted within one slot according to a table containing information on slots to which the PDSCHs are mapped, starting symbols, and the number or length of symbols, and the terminal may set a bit representing HARQ-ACK information corresponding to a PDSCH opportunity to NACK. If an indication of a binary OR operation of HARQ-ACK information restricted within a slot is received, the terminal may set the HARQ-ACK information to ACK when a PDSCH is received from a TRP within a corresponding slot, and set the HARQ-ACK information to NACK when the PDSCH is not received. Since the HARQ-ACK bit width is determined by the maximum number of PDSCHs for each TRP according to a table (which contains information on a slot to which the PDSCH is mapped, a starting symbol, and the number or length of symbols) when each TRP schedules only one PDSCH within the slot, it is possible to avoid unnecessary NACK information transmission and reduce the number of bits of the type-1 HARQ-ACK codebook. Although the method described in embodiment 1-2 is advantageous in terms of not impairing the degree of freedom of PDSCH mapping because there is no limitation on the PDSCH mapping type, it is disadvantageous in terms of limiting the number of PDSCHs that can be mapped within one slot to 1 for each TRP as in embodiment 1-1.

The HARQ-ACK feedback bits may be determined as follows. For example, the above [ pseudo code 1 ] may be replaced by [ pseudo code 5 ]. Serving cell c (M) may be calculated using the steps as follows [ pseudo code 5 ]_A,C) A set of candidate PDSCH receivers.

[ pseudo code 5 Start ]

-step 1: initialize j to 0, M_A,CIs initialized to an empty set and the HARQ-ACK transmission timing index (k) is initialized to 0.

-step 3-2: if a terminal can receive more than one PDSCH in a slot, and if the corresponding slot is not for NC-JT, pairs R can be mapped to differentCounting the maximum number of PDSCHs of the symbol, increasing j by 1 until the end of the counting, and adding j to M_A,CIn (1).

-step 3-3: counting a maximum number of PDSCHs in R that can be mapped to different symbols, increasing j by 1 until the end of the count, and adding j to M if a terminal can receive more than one PDSCH within a slot, if the corresponding slot is for NC-JT, and if an indication of a slot-level bundling configuration for the slot for NC-JT is not received via higher layer signaling_A,CIn (1).

-step 3-4: adding j to M if a terminal can receive more than one PDSCH within a slot, if the corresponding slot is for NC-JT, and if an indication of a slot-level bundling configuration for the slot for NC-JT is received via higher layer signaling_A,CAnd j is increased by 1.

-step 4: k is incremented by 1 and the process starts again at step 2.

[ pseudocode 5 end ]

In [ pseudo code 5 ], when slot-level bundling is configured for slots for NC-JT through higher layer signaling, only one j is added to M for slots for NC-JT_A,CThis produces the same result as that obtained by applying a binary OR operation to HARQ-ACK information corresponding to a PDSCH that can be transmitted by one TRP in a corresponding slot.

This embodiment may be extended such that HARQ-ACK slot level bundling may or may not be configured for one TRP (e.g., a serving TRP for a terminal to use when receiving a single PDSCH) and each of the TRPs excluding the serving TRP. For example, when configuring whether to apply HARQ-ACK slot level bundling for all TRPs via higher layer signaling and transmitting an indication of HARQ-ACK slot level bundling for all TRPs, whether to apply HARQ-ACK slot level bundling for a serving TRP may be indicated via separate higher layer signaling.

Fig. 13 illustrates a type 1HARQ-ACK codebook structure according to an embodiment, which is different according to whether HARQ-ACK slot level bundling is applied. In particular, fig. 13 illustrates three exemplary type 1HARQ-ACK codebook structures when the configuration for HARQ-ACK slot level bundling for all TRPs and the configuration for HARQ-ACK slot level bundling for a serving TRP are independently indicated.

Referring to fig. 13, structures # 113-00 show type 1HARQ-ACK codebook structures used when HARQ-ACK slot level bundling for all TRPs is not indicated. In this case, HARQ-ACK feedback bits 13-05 and 13-10 (equal in number to the total PDSCH that individual TRPs may be transmitted within a slot) determined from a table containing information of the slot to which the PDSCH is mapped, the starting symbol and the number or length of symbols are bundled into a type 1HARQ-ACK codebook structure. Although the number of PDSCHs that can be transmitted within one slot per TRP is not limited, this structure has a disadvantage in that the number of HARQ-ACK feedback bits linearly increases with the number of TRPs.

Structure # 213-15 shows a type 1HARQ-ACK codebook structure used when both HARQ-ACK slot level bundling for all TRPs and HARQ-ACK slot level bundling for a serving TRP are indicated. In this case, the number of PDSCHs that each TRP can transmit within a slot is limited to 1, and the HARQ-ACK feedback bits 13-20 and 13-25 are determined based on whether the PDSCH is transmitted in the corresponding slot. Although the number of PDSCHs that can be transmitted within a slot is limited to 1 for all TRPs, the number of HARQ-ACK feedback bits per TRP within the slot is reduced to 1, thereby reducing the total number of HARQ-ACK feedback bits.

Structure # 313-30 shows a type 1HARQ-ACK codebook structure used when HARQ-ACK slot level bundling for all TRPs is indicated and HARQ-ACK slot level bundling for the serving cell is not indicated. In this case, HARQ-ACK feedback bits 13-35 of the serving TRP (equal in number to the PDSCH in which the serving TRP can be transmitted within a slot) and HARQ-ACK feedback bits 13-40 of the coordinating TRP, which are determined according to a table containing information on the slot to which the PDSCH is mapped, the starting symbol, and the number or length of symbols, are bundled into a type 1HARQ-ACK codebook structure. In this case, the number of PDSCHs that the serving TRP can transmit within a slot is not limited, and the number of PDSCHs that the coordinated TRP can transmit is limited to 1. The advantage of this structure is that the number of HARQ-ACK feedback bits coordinating the TRP is reduced without any restriction on the scheduled PDSCH serving the TRP.

Examples 1 to 3:method for limiting number of HARQ-ACK feedback bits per slot

Embodiments 1-3 provide a method for limiting the number of HARQ-ACK feedback bits specified for each slot and limiting the number of PDSCHs that a serving or coordinated TRP may transmit within a slot to 1. An advantage of this approach is that the maximum number of PDSCHs that can be transmitted per TRP in each slot within the HARQ feedback bit width limited by the base station can be indicated. The HARQ-ACK feedback bit width limited by the base station may be determined according to a PUCCH coverage for transmitting the HARQ-ACK codebook.

Assuming that the number of TRPs for transmitting a PDSCH during a slot in a serving cell is N, the maximum number of PDSCHs that can be transmitted within the slot may be determined according to a table containing information on the slot to which the PDSCH is mapped, a starting symbol, and the number or length of symbols. When no indication of a configuration for HARQ-ACK bundling for each slot is received via higher layer signaling and an indication of a configuration for transmission of up to 2 codewords through PDSCH is received, the number of HARQ-ACK feedback bits corresponding to a slot may be calculated by N × maxNrofPDCCHs × 2. The number of HARQ-ACK feedback bits may also be calculated by N × maxNrofPDCCHs when an indication of a configuration for HARQ-ACK bundling for each slot is received via higher layer signaling or no indication of a configuration for transmission of up to 2 codewords through PDSCH is received. This assumes that the maximum number of PDSCHs that can be mapped in one slot per TRP is maxNrofPDCCHs, and the maximum number of PDSCHs that can be transmitted in one slot per TRP can be limited to 1 by limiting the number of HARQ-ACK feedback bits that can be transmitted in a slot to less than maxNrofPDCCHs.

For example, when an indication of a configuration for HARQ-ACK bundling for each slot is received or no indication of a configuration for transmission of up to 2 codewords through the PDSCH is received, if the number N × maxNrofPDCCHs of HARQ-ACK feedback bits that can be transmitted in one slot is greater than a limit value of the number of HARQ-ACK feedback bits designated for each slot, the number of HARQ-ACK feedback bits designated for each slot may be reduced to maxNrofPDCCHs + N-1 by limiting the maximum number of PDSCHs that can be transmitted in the slot per coordinated TRP (excluding TRP) to 1. If the number of HARQ-ACK feedback bits designated for each slot, which have been reduced to maxNrofPDCCHs + N-1, is greater than a limit value for the number of HARQ-ACK feedback bits designated for each slot, the number of HARQ-ACK feedback bits designated for each slot is reduced to N (e.g., N is a positive integer) by limiting the maximum number of PDSCHs that a serving TRP may transmit in the slot to 1.

Table 6 provides an example of information on whether to limit the maximum number of PDSCHs that can be scheduled per TRP according to the number of HARQ-ACK feedback bits, assuming that the limit value of the number of HARQ-ACK feedback bits designated for each slot is K, when an indication of a configuration of HARQ-ACK bundling for each codeword is not received via higher layer signaling and an indication of a configuration of transmission of at most 2 codewords through the PDSCH is received.

[ TABLE 6 ]

Table 7 provides an example of information on whether to limit the maximum number of PDSCHs that can be scheduled per TRP according to the number of HARQ-ACK feedback bits when an indication of a configuration of HARQ-ACK bundling for each codeword is received via higher layer signaling or no indication of a configuration of transmission of at most 2 codewords through the PDSCH is received, assuming that the limit value of the number of HARQ-ACK feedback bits designated for each slot is K.

[ TABLE 7 ]

Considering the number of type 1HARQ-ACK codebook bits and the degree of freedom of PDSCH mapping, the maximum number of PDSCHs that a serving TRP or a coordinated TRP can transmit can be determined not to exceed a limit value of the number of HARQ-ACK feedback bits designated for each slot by using table 6 and table 7.

Example 2:HARQ-ACK codebook combination of multiple PUCCHs for NC-JT

When using NC-JT, a terminal may transmit a HARQ-ACK codebook corresponding to a PDSCH transmitted in a different cell, TRP, and/or beam to a base station via a single PUCCH or multiple PUCCHs. For a terminal transmitting a HARQ-ACK codebook via a plurality of PUCCHs, different PUCCH resources may be indicated in DCI scheduling a PDSCH to be transmitted by a plurality of TRPs.

Fig. 14 illustrates a method for configuring a HARQ-ACK codebook to be transmitted through a plurality of PUCCHs according to an embodiment.

Referring to fig. 14, example # 114-00 shows a case where a terminal individually configures HARQ-ACK codebooks corresponding to PDSCHs 14-05, 14-10 and 14-15 transmitted in different cells, TRPs and/or beams. The terminal may transmit the PUCCHs 14-30 and 14-35 individually to the TRPs, which have transmitted the corresponding PDSCHs, on PUCCH resources indicated by DCI carried in the PDCCHs 14-20 and 14-25. By transmitting the HARQ-ACK codebooks 14-40 and 14-45 to the respective TRPs, the method is advantageous in preventing the number of HARQ-ACK codebook bits from linearly increasing with the number of TRPs.

Example #2 shows the terminal configuring HARQ-ACK codebooks 14-70 (with HARQ-ACK feedback bits corresponding to PDSCHs 14-55, 14-60, and 14-65 transmitted in various cells, TRPs, and/or beams). In this case, the terminal may multiplex the HARQ-ACK codebook corresponding to the TRP into a single HARQ-ACK codebook 14-70 and transmit the PUCCHs 14-85 and 14-90 carrying the HARQ-ACK codebook 14-70 to all the TRPs on the PUCCHs individually indicated by the DCIs carried in the PDCCHs 14-75 and 14-80 to improve HARQ-ACK feedback reliability.

The following embodiments provide a method for configuring a HARQ-ACK codebook for each TRP, a method for configuring concatenation (collocation) of HARQ-ACK codebooks for all TRPs, and a method for transmitting an indication of the configuration to a terminal when the HARQ-ACK codebook is transmitted through a plurality of PUCCHs for NC-JT.

Example 2-1:configuration method based on higher layer signaling

When HARQ-ACK feedback bits corresponding to a PDSCH from a plurality of TRPs are transmitted based on a separate PUCCH resource indication, an HARQ-ACK codebook or an HARQ-ACK codebook for each TRP may be configured by concatenating HARQ-ACK codebooks for all TRPs. The base station may send an indication of the HARQ-ACK codebook configuration to the terminal via higher layer signaling.

When the base station transmits an indication of the HARQ-ACK codebook configuration for each TRP to the terminal via higher layer signaling, the terminal may generate a HARQ-ACK codebook for each of the TRPs and transmit the HARQ-ACK codebook on the PUCCH resource indicated by the DCI transmitted by the TRP. For example, when receiving the indication of the type 1HARQ-ACK codebook configuration, the terminal may determine HARQ-ACK codebook bits based on HARQ-ACK feedback information corresponding to a PDSCH scheduled by DCI indicating the same PUCCH resource. Upon receiving the indication of the type 2HARQ-ACK codebook configuration, the terminal may determine HARQ-ACK codebook bits based on HARQ-ACK feedback information corresponding to a PDSCH scheduled by DCI indicating the same PUCCH resource, based on a total DAI and a counter DAI of DCI scheduling the same PUCCH resource, via the above [ pseudo code 3 ].

When the base station transmits an indication of the configuration of the HARQ-ACK codebook concatenating all TRPs to the terminal via higher layer signaling, the terminal may determine the slot to which the PUCCH carrying the HARQ-ACK feedback bits is mapped based on the PDSCH-to-HARQ _ feedback timing indicator indicating the slot interval between the DCI scheduled PDSCH transmitted by each TRP and the corresponding HARQ-ACK feedback. The terminal may also determine HARQ-ACK codebook bits based on HARQ-ACK feedback information corresponding to a PDSCH scheduled by DCI scheduling a PUCCH mapped to the same slot. For example, when receiving the indication of the type 1HARQ-ACK codebook configuration, the terminal may generate the HARQ-ACK codebook via [ pseudo code 1 ] and [ pseudo code 2 ] described above. If PUCCH resources indicated by DCI scheduling PUCCH in the same slot are different from each other, respective HARQ-ACK codebooks configured based on the PUCCH resources are concatenated to be bundled into HARQ-ACK codebooks of all TRPs. When receiving the indication of the type 2HARQ-ACK codebook, the terminal may determine HARQ-ACK codebook bits based on the counter DAI and the total DAI of the DCI scheduling the PUCCH in the same slot.

Example 2-2:method based on conditions of symbol level overlap

When a terminal is able to transmit a plurality of PUCCHs mapped to at least one identical symbol in a slot, an HARQ-ACK codebook or an HARQ-ACK codebook for each TRP may be configured by bundling the HARQ-ACK codebook for each TRP for all TRPs depending on whether the plurality of PUCCH resources overlap at a symbol level. If a plurality of PUCCH resources overlap at a symbol level, the PUCCH resources allocated in the slot may include at least one identical symbol. When multiple PUCCHs are scheduled in a slot for HARQ-ACK feedback corresponding to a PDSCH from multiple TRPs, if PUCCH resources indicated by DCI from multiple TRPs overlap at the symbol level, a HARQ-ACK codebook corresponding to a PDSCH scheduled by DCI may be bundled together. When a plurality of PUCCHs are scheduled in a slot for HARQ-ACK feedback corresponding to a PDSCH from a plurality of TRPs, if PUCCH resources indicated by DCIs from the plurality of TRPs do not overlap at a symbol level, HARQ-ACK codebooks corresponding to PDSCHs scheduled by DCIs from the respective TRPs are respectively configured to be carried by PUCCHs transmitted on the corresponding PUCCH resources.

Fig. 15 illustrates a method for configuring a HARQ-ACK codebook based on whether a plurality of PUCCH resources overlap at a symbol level according to an embodiment. Specifically, fig. 15 shows a case where the HARQ-ACK codebook for each TRP is configured based on a plurality of PUCCH resources overlapping at a symbol level, and a case where the HARQ-ACK codebook for each TRP is all bundled together based on a plurality of PUCCH resources not overlapping at a symbol level.

Referring to fig. 15, in case # 115-00, feedback corresponding to PDSCHs 15-25 and 15-35 indicated by DCI carried in PDCCHs 15-15 and 15-20 from a plurality of TRPs is bundled into a HARQ-ACK codebook 15-35, which HARQ-ACK codebook 15-35 is carried by a plurality of PUCCHs 15-05 and 15-10 scheduled in a slot. Since PUCCH resources indicated by DCI scheduling PUCCH in the same slot are different from each other, the terminal may configure an HARQ-ACK codebook corresponding to the PUCCH resources and concatenate the HARQ-ACK codebook into an HARQ-ACK codebook 15-35, the HARQ-ACK codebook 15-35 being transmitted to each TRP.

In case # 215-40, the PUCCH resources indicated by DCIs carried in PDCCHs 15-55 and 15-60 from multiple TRPs for scheduling multiple PUCCHs 15-45 and 15-50 in a slot do not overlap at a symbol level. The terminal may generate HARQ-ACK codebooks 15-75 and 15-80 corresponding to PDSCHs 15-65 and 15-70 scheduled by DCIs from a plurality of TRPs and transmit the HARQ-ACK codebooks on PUCCH resources 15-45 and 15-50 indicated by DCIs from the respective TRPs.

When the terminal does not support multiple PUCCHs mapped to at least one identical symbol in a slot, the terminal may bundle information items of the multiple PUCCHs into a single PUCCH. The terminal may also bundle multiple HARQ-ACK codebooks carried by multiple PUCCHs mapped to at least one symbol into a HARQ-ACK codebook. The HARQ-ACK codebook configured by the terminal may be carried by a PUCCH transmitted on a PUCCH resource allocated by the serving TRP.

Examples 2 to 3:method for scheduling multiple PUCCHs by using single PDCCH

In NC-JT, a terminal may receive PDSCH scheduling information of all TRPs from a serving TRP via DCI. A plurality of PUCCH resources may be allocated via DCI transmitted by a serving TRP in order to receive HARQ-ACK feedback corresponding to a PDSCH transmitted from the plurality of TRPs. More specifically, the base station may configure DCI transmitted by a serving TRP to indicate PUCCH resources corresponding to TRPs participating in PDSCH coordinated transmission, and the terminal may generate a HARQ-ACK codebook corresponding to PDSCH from all TRPs and separately transmit HARQ-ACK feedback bits on the PUCCH resource of each TRP. However, as described in embodiment 2-1 or 2-2, the terminal may also be configured to generate a HARQ-ACK codebook for each TRP corresponding to a PDSCH from all TRPs, or to generate a HARQ-ACK codebook bundling the HARQ-ACK codebook for each TRP corresponding to a PDSCH from all TRPs.

Table 8 provides an example of information on PUCCH resources corresponding to TRPs participating in PDSCH coordinated transmission, the PUCCH resources being indicated by DCI transmitted by a serving TRP. In order to configure a single DCI to indicate a plurality of PUCCH resources, a PUCCH resource indicator for each TRP may be defined to indicate a PUCCH resource for each TRP. Although this method is advantageous in improving the degree of freedom of PUCCH resource allocation because PUCCH resources are indicated for each TRP, it also has a disadvantage in that the PUCCH resource indicator bits per TRP increases DCI overhead.

[ TABLE 8 ]

If a plurality of PUCCH resource indicators indicate the same PUCCH resource, the terminal can transmit an HARQ-ACK codebook corresponding to a PDSCH from a TRP corresponding to a resource indicator of the PUSCH on a PUCCH resource commonly indicated by the PUCCH resource indicators indicating the same PUCCH resource.

Table 9 below provides an example of information on PUCCH resources corresponding to TRPs participating in PDSCH coordinated transmission, which are indicated by DCI transmitted by a serving TRP. In order for a single DCI to indicate a plurality of PUCCH resources, the number of PUCCH resources included in a PUCCH resource set may be increased according to the number of coordinated TRPs, and a single code point (code point) of a PUCCH resource indicator is allowed to indicate a plurality of PUCCH resources corresponding to all TRPs. This approach is advantageous in indicating multiple PUCCH resources without compromising the number of PUCCH resource indicator bits in DCI as in the case where a single PUCCH resource is indicated, even if the number of PUCCH resource sets is transmitted to the terminal via higher layer signaling.

[ TABLE 9 ]

Examples 2 to 4:method for scheduling multiple PUCCHs by using multiple PDCCHs

As an example of NC-JT, a terminal may receive PDSCH resource allocation information transmitted by coordinated TRPs from respective coordinated TRPs via PDCCH or DCI. In this case, the coordinated TRP may separately receive HARQ-ACK feedback corresponding to the PDSCH transmitted by the coordinated TRP through a plurality of PUCCHs for non-ideal backhaul between the TRPs. For this, when NC-JT is indicated by a plurality of PDCCHs or DCIs, a PUCCH resource indicator indicating a PUCCH resource for HARQ-ACK feedback in the DCI should be set to a different value. That is, in NC-JT based on a plurality of DCIs, each coordinated TRP may receive HARQ-ACK/NACK feedback through a PUCCH resource of each TRP, and a terminal may not expect PUCCH resource indicators from the coordinated TRPs participating in NC-JT to be set to the same value. The terminal may separately generate HARQ-ACK codebooks corresponding to the PDSCHs from the respective coordinated TRPs and transmit the HARQ-ACK codebooks on separate PUCCH resources. The terminal may not desire to bundle the HARQ-ACK codebook corresponding to the PDSCH transmitted by the coordinated TRP.

For TRP-specific PUCCH resource allocation, the PUCCH resource indication is restricted differently depending on whether the terminal supports multi-panel or multi-beam simultaneous transmission (i.e., depending on UE capabilities). For example, if the terminal supports UL multi-panel/beam transmission or spatial relationship/TCI state configuration, the terminal may receive an indication of the configuration of the PUCCH (carrying different panel/beam/spatial information or TCI state on the same OFDM symbol) to be transmitted to the coordinated TRP. However, if the terminal does not support UL multi-panel/beam transmission or spatial relationship/TCI state configuration, the terminal may not expect to receive an indication of the configuration of the PUCCH to be sent to the coordinated TRP (carrying different panel/beam/spatial information or TCI state on the same OFDM symbol). When a terminal that does not support UL multi-panel/beam transmission or spatial relationship/TCI state configuration receives an indication of configuration of different PUCCH resources for NC-JT at the same OFDM symbol, the terminal can transmit information integrated according to the ACK/NACK feedback bundling method of embodiment 2-2 on a single PUCCH resource, ignoring the above PUCCH transmission operation per TRP. In this case, a single PUCCH resource may be determined according to a predetermined priority order (e.g., a priority order of PDCCH or PDSCH resources associated with different PUCCH resources).

As described above, a detailed method for configuring an HARQ-ACK codebook corresponding to a PDSCH transmitted by a coordinated TRP may be performed.

multi-TRP coordinated transmission may be achieved in both an ideal backhaul environment that takes into account no backhaul delay and a non-ideal backhaul environment that takes into account backhaul delay. In both ideal backhaul and non-ideal backhaul environments, an indication of a configuration of a PUCCH resource set for a TRP may be transmitted via RRC signaling, and a specific PUCCH resource may be allocated via DCI. An indication of a configuration of at least one PDSCH resource allocation and at least one corresponding PUCCH resource allocation per TRP may also be transmitted. In a non-ideal backhaul environment, an indication of a configuration of PUCCH resources of each coordinated TRP overlapping in at least one of a time domain, a frequency domain, and a special domain may be transmitted to a terminal. When PUCCH resources overlap in the time domain, the overlapping PUCCH resources may be at least one OFDM symbol in the same slot, as described below with reference to fig. 16.

Example 3:method for transmitting UL Control Information (UCI) on overlapping resources

Embodiment 3 provides a UCI transmission method of PUCCH resources (at least partially overlapping in an NC-JT scenario) allocated to a terminal.

Embodiment 3 provides a method of selecting at least one of a plurality of PUCCH resources based on various conditions in an NC-JT scenario, and a method of multiplexing UCI in a predetermined priority order based on various resource conditions.

Embodiment 3 also provides a method for adjusting the position of PUCCH resources for UCI transmission.

Embodiment 3 provides a method in which a terminal does not expect overlapping PUSCH resources from a base station.

Embodiment 3 provides a method of transmitting individual HARQ-ACK/NACK payload/feedback or combined HARQ-ACK/NACK payload/feedback.

Example 3-1:method for discarding or multiplexing a plurality of UCIs to be transmitted in priority order of PUCCH resources determined based on predetermined conditions

Fig. 16 illustrates a PUCCH resource configuration operation of a terminal according to an embodiment.

Referring to fig. 16, since two PUCCH resources (PUCCH #1 and PUCCH #2)16-05 and 16-10 for NC-JT overlap at least one OFDM symbol, a terminal may transmit UCI scheduled on one PUCCH resource having a higher priority (e.g., UCI of TRP # 116-35) and discard UCI scheduled on another PUCCH resource having a lower priority (e.g., UCI of RP # 216-40).

To determine to discard a particular UCI, various conditions may be considered. In the embodiments disclosed below, the various UCI include HARQ-ACK.

The terminal may preferably transmit the HARQ-ACK codebook corresponding to the PDSCH 15-25 and 16-30 from a specific TRP on the PUCCH resource indicated by the DCI carried in the PDCCHs 16-15 and 16-30 transmitted by the TRP. The particular TRP with the higher priority may be determined by the base station. The TRP may be implicitly understood as the TRP of the first connection to the base station or the TRP of the serving cell. PUCCH scheduled on PUCCH resources for TRP having lower priority may be discarded.

Alternatively, the terminal may transmit the HARQ-ACK codebook scheduled on the PUCCH resource indicated by the DCI (received in a specific CORESET or/and search space configured by the base station) and discard the HARQ-ACK codebook scheduled on other PUCCH resources.

The terminal may preferably transmit specific UCI content designated by the base station. When the UCI scheduled on PUCCH # 116-05 is a HARQ-ACK codebook and the UCI scheduled on PUCCH # 216-10 is CSI, the terminal may transmit a HARQ-ACK codebook transmission based on PUCCH #1 resource based on priority. However, CSI transmission based on the PUCCH #2 resource may not be performed. The UCI content may be prioritized in the order HARQ-ACK > SR > CSI (CQI, PMI, RI) or SR > HARQ-ACK > CSI (CQI, PMI, RI). The UCI content may also be prioritized in the order of HARQ-ACK and SR > CSI.

Alternatively, if the base station sets the same priority for all types of CSI, the terminal may determine priority for the type of CSI using equation 1 below and preferably transmit the type of CSI in preference to other types of CSI. Pri for determining priority_iCSIThe lower the value of (y, k, c, s), the higher the priority.

[ EQUATION 1 ]

pri_iCSI(y，k，c，s)＝2·N_cells·M_s·y+N_cells·Ms·k+M_s·c+s

In equation 1, y may be set to 0 when the PUSCH carries an aperiodic CSI report, to 1 when the PUSCH carries a semi-persistent CSI report, and to 3 when the PUCCH carries a periodic CSI report. Further, k may be set to 0 when the CSI includes L1-RSRP, and may be set to 1 when the CSI does not include L1-RSRP. In addition, c may be set as an index of a serving cell index, N_cellsMay be set to a value of a higher layer parameter maxNrofServinCells, s may be set to a value of a CSI report (CSI-report) identifier CSI-report configID, and M_sMay be set to a value indicating the number of CSI reporting configurations MaxNrofSCI-ReportConfigurations (e.g., 0 to 47) of the base station.

As shown in the time domain in fig. 16, if resources for CSI reporting overlap at least one OFDM symbol, two CSI reports may collide with each other. In particular, if the value of y is neither 2 nor 3 and differs between the two CSI reports, the terminal may discard the CSI having the larger pri_iCSICSI report of (y, k, c, s). If the y value between two CSI reports is equal, then the one with the larger pri can be discarded_iCSICSI report of (y, k, c, s).

UCI content of larger size or having characteristics of eMBB/URLLC may be prioritized if transmission of the same type of UCI content is indicated. UCI may be prioritized by considering various metrics in a mixed manner.

Alternatively, the terminal may preferentially transmit UCI scheduled on a PUCCH resource longer than a PUCCH resource for another UCI in the time domain. UCI scheduled on PUCCH resources 16-70 occupying 10 OFDM symbols may be prioritized over UCI scheduled on PUCCH resources 16-80 occupying 4 OFDM symbols.

The terminal may preferentially transmit the HARQ-ACK codebook indicated with a specific RNTI among various RNTIs. The RNTIs may include C-RNTI, random access RNTI (RA-RNTI), system information RNTI (SI-RNTI), and paging RNTI (P-RNTI), which may be prioritized in the order of enumeration.

The terminal may preferentially transmit UCI scheduled on a PUCCH resource indicated at the latest PDCCH transmission timing, i.e., UCI scheduled on a PUCCH resource indicated at the oldest PUCCH transmission timing.

If PUCCH resources allocated for the short PUCCH supporting

PUCCH formats

0 and 2 and the long PUCCH supporting PUCCH formats 1, 3, and 4 overlap, the short (or long) PUCCH may be discarded and the long (or short) PUCCH may be transmitted. In this case, the terminal can prioritize the PUCCH resources by applying the above-described prioritization method in a mixed manner.

UCI may be transmitted on PUSCH resources and PUCCH resources. When considering both PUCCH and PUSCH resources, the terminal may preferentially transmit UCI scheduled on the configured granted PUSCH resource or the granted-based PUSCH resource.

Although the description is directed to transmission overlapping at least one OFDM symbol in the time domain, if at least two PUCCH resources are allocated in a slot even though they do not overlap at any symbol in the time domain, a terminal may transmit only UCI scheduled on the PUCCH resources prioritized as described above.

Although prioritization is performed based on the particular metrics above, the present disclosure is not limited by metrics. That is, prioritization may be performed using other metrics as well as any one or combination of the above metrics.

As shown in fig. 16, when two PUCCH resources for NC-JT overlap at least one OFDM symbol, the terminal may discard transmissions scheduled on a PUCCH resource having a lower priority and multiplex UCI of two TRPs associated with NC-JT on a PUCCH resource having a higher priority to transmit them together.

In this case, UCI may be multiplexed on PUCCH resources having higher priority in consideration of various conditions. As described above with reference to fig. 10 to 13, UCI may be multiplexed in the same manner as the HARQ-ACK codebook.

The terminal may multiplex UCI scheduled on two different PUCCH resources on a PUCCH resource for a TRP having a higher priority to transmit them together. In this case, the base station may configure a specific TRP. A specific TRP may be implicitly understood as a TRP of a base station or a TRP of a serving cell connected first. Transmissions scheduled on PUCCH resources for TRPs with lower priorities may be dropped.

The terminal may multiplex UCI on PUCCH resources scheduled by DCI (received in the CORESET or/and search space prioritized by the base station) to transmit them together. UCI scheduled in PUCCH resources having lower priority may be discarded.

The terminal may preferably transmit UCI carrying UCI contents prioritized over other contents on a corresponding PUCCH resource. If the UCI scheduled in PUCCH # 116-05 is a HARQ-ACK codebook and the UCI scheduled in PUCCH # 216-10 is CSI, the terminal can multiplex the HARQ-ACK codebook and CSI on PUCCH # 116-05 allocated for the HARQ-ACK codebook based on priority. The CSI transmission scheduled on PUCCH #2 may be discarded. The UCI content may be prioritized in the order HARQ-ACK > SR > CSI (CQI, PMI, RI) or SR > HARQ-ACK > CSI (CQI, PMI, RI). The UCI content may also be prioritized in the order of HARQ-ACK and SR > CSI.

If the base station determines the priorities of all types of CSI to be the same, the terminal may determine the priorities for the types of CSI through equation (1) as described above and preferably transmit the types of CSI in preference to other types of CSI. Pri for determining priority_iCSIThe lower the value of (y, k, c, s), the higher the priority.

If as shown in the time domain in fig. 16The resources for CSI reporting overlap at least one OFDM symbol, and then two CSI reports may collide with each other. If the y-value between two CSI reports is equal, then there is a larger pri_iCSIThe CSI report of (y, k, c, s) may be discarded or compared to the one with smaller pri_iCSIThe CSI reports of (y, k, c, s) are multiplexed together into a CSI report to be transmitted together.

UCI content of larger size or having characteristics of eMBB/URLLC may be prioritized if transmission of the same type of UCI content is indicated. The priority of UCI may be determined by considering various metrics in a mixed manner.

Alternatively, the terminal may multiplex UCI designated by the base station on a PUCCH resource longer than that for another PUCCH resource in the time domain to transmit them together. UCI scheduled on PUCCH resources 16-70 occupying 10 OFDM symbols may be prioritized over UCI scheduled on PUCCH resources 16-80 occupying 4 OFDM symbols.

The terminal may multiplex UCI designated by the base station on PUCCH resources indicated with the specific RNTI to transmit them together. The RNTIs may include C-RNTI, RA-RNTI, SI-RNTI, and P-RNTI, which may be prioritized in the order of enumeration.

The terminal may multiplex UCI on a PUCCH resource indicated by a PDCCH transmitted at the latest PDCCH transmission timing, i.e., UCI scheduled on a PUCCH resource indicated at the oldest PUCCH transmission timing.

If PUCCH resources allocated for the short PUCCH supporting

PUCCH formats

0 and 2 and/or the long PUCCH supporting PUCCH formats 1, 3, and 4 overlap, the terminal may select one of the PUCCH resources in which to multiplex UCI to transmit them together. In this case, the terminal can prioritize the PUCCH resources by applying the above-described prioritization method in a mixed manner.

UCI may be transmitted on PUSCH resources and PUCCH resources, and when both PUCCH and PUSCH resources are considered, the terminal may preferentially multiplex UCI on the configured granted PUSCH resources or grant-based PUSCH resources to transmit them together. In this case, UCI scheduled on PUCCH resources may be discarded.

Although the above description is directed to when transmissions overlap at least one OFDM symbol in the time domain, if at least two PUCCH resources are allocated in a slot even if they do not overlap at any symbol in the time domain, the terminal may multiplex UCI on PUCCH resources that are prioritized over other resources as described above so as to transmit them together.

Fig. 17 is a flowchart illustrating an operation of a terminal according to an embodiment. Specifically, fig. 17 is a flowchart showing the operation of the terminal according to embodiment 3-1.

Referring to fig. 17, in step 17-10, the terminal receives PUCCH resource-related information and base station beam-related information via an RRC message. The PUCCH resource-related information and the base station beam-related information may include PUCCH resource information, PUCCH resource set configuration information, PUCCH resource and spatial relationship-related information, RS configuration and quasi co-location (QCL) information for beam management, and TCI status information.

In step 17-30, the terminal identifies each of UCI-related information or PUCCH resource-related information indicated by a plurality of PDCCHs received from a plurality of base stations. The UCI-related information may include HARQ-ACK and SR information, and the PUCCH resource-related information may include PUCCH resource indicator information.

In step 17-50, the terminal determines whether PUCCH resources allocated in the same slot overlap at least one OFDM symbol. This determination may be made based on the resource information received in step 17-10.

If it is determined in steps 17-90 that PUCCH resources allocated in the same slot overlap at least one OFDM symbol, the terminal makes a PUCCH determination or UCI-related determination based on the result of the prioritization performed as described above. The UCI-related determination may include a determination of whether to multiplex UCI, a multiplexing order, and a determination of whether to transmit UCI. If it is determined in steps 17-70 that PUCCH resources allocated in the same slot do not overlap at least one OFDM symbol, the terminal separately transmits each of UCI on the scheduled corresponding PUCCH resource.

Example 3-2:resource location adjustment based on certain conditions (priorities)

When two PUCCH resources for NC-JT overlap at least one OFDM symbol, an OFDM symbol position of one of the two PUCCH resources may be adjusted according to a priority order. The priority order may be determined by applying at least one of the conditions described in embodiment 3-1. That is, at least one of TRP, CORESET/search space, UCI content, PUCCH length, RNTI type, PDCCH transmission timing, and configured grant UL/grant-based UL may constitute a condition for determining and setting priority. Embodiment 3-2 is directed to a method of adjusting resource locations to transmit UCI that has been prioritized by a terminal.

Referring again to fig. 16, in the lower part 16-45, it is assumed that NC-JT is allocated two PUCCH resources 16-50 and 16-60, 16-50 for the short PUCCH and 16-60 for the long PUCCH. The PUCCH resources overlap over the two OFDM symbols 16-62 and 16-64. Unlike embodiment 3-1 in which a terminal transmits UCI scheduled on one PUCCH resource having a higher priority and discards UCI scheduled on another PUCCH resource having a lower priority, the terminal may transmit both UCI by adjusting PUCCH resource positions at an OFDM symbol level. The OFDM symbol level adjustment to the PUCCH resource position may be determined in consideration of the starting position of the PUCCH resource and the length of the OFDM symbol. That is, the PUCCH resource may be shifted to the earliest occurring UL transmission resource in the OFDM symbol where the PUCCH resources do not overlap. The OFDM symbol length may be preserved to avoid modification of the PUCCH format. However, in this embodiment, the PUCCH format may also be modified.

PUCCH resources 16-50 may be assumed to be prioritized over PUCCH resources 16-60. In this case, the PUCCH resources 16-60 scheduled on OFDM symbols 16-62 and 16-64 may be moved to a position available for UL transmission in order to transmit the corresponding UCI, since the PUCCH resources 16-60 have a lower priority. If

symbols

6 and 7 are UL resources or resources that can be designated as UL resources, the terminal may move PUCCH resources 16-60 scheduled on

OFDM symbols

4 and 5 onto

OFDM symbols

6 and 7 in order to transmit corresponding UCI thereon. If

symbols

6 and 7 are DL resources or resources that may not be designated as UL resources, the terminal may transmit the corresponding UCI on the other two OFDM symbol resources available for UL transmission within slot # 3. If there are more than two OFDM symbols available for UL transmission, the terminal may transmit the corresponding UCI on the earliest occurring UL resource after

symbols

4 and 5 within slot # 3.

The terminal may adjust a starting position of a PUCCH resource having a lower priority to prevent PUCCH resources for NC-JT from overlapping in the time domain. In this case, it is not necessary to modify the PUCCH format. An indicator value of a PUCCH resource having a lower priority may be adjusted to prevent overlapping of PUCCH resources for NC-JT. That is, a new PUCCH resource that does not overlap with a PUCCH resource having a higher priority at a symbol level may be selected in the PUCCH resource set configured via RRC. In this case, it is not necessary to modify the PUCCH format.

PUCCH resources 16-60 may be assumed to be prioritized over PUCCH resources 16-50. The terminal may move PUCCH resources 16-50 to a position available for UL transmission in order to transmit the corresponding UCI because PUCCH resources 16-50 have a lower priority. Here, the terminal may shift PUCCH resources 16-50 scheduled on OFDM symbols 2 to 5 onto OFDM symbols 6 to 9 to avoid overlapping PUCCH resources 16-60 at OFDM

symbols

4 and 5. If the OFDM symbols 6 to 9 are DL resources or resources that cannot be designated as UL resources, the terminal may transmit the corresponding UCI on symbols 10 to 13 starting from symbol 10, which is the earliest symbol available for UL transmission, maintaining a symbol length of 4 within slot #3 without modifying the PUCCH format.

Alternatively, it may be assumed that NC-JT is allocated two long PUCCH resources, and PUCCH resource 1670 takes precedence over PUCCH resource 1680. In this case, the terminal may move the PUCCH resources 16-80 scheduled on OFDM symbols 2 to 5 to a position available for transmission because PUCCH resources 16-80 have a lower priority. Here, the terminal may transmit the corresponding UCI on PUCCH resources available for UL transmission in the next slot (slot #4) to prevent PUCCH resources having lower priority from overlapping PUCCH resources 16-70 scheduled on symbols 4 to 13 in slot #3 in the time domain. If the terminal determines that UCI scheduled on a PUCCH resource having a lower priority cannot be transmitted in slot #3, the terminal may discard the UCI transmission.

The terminal may modify the PUCCH format of PUCCH resources 16-80 to fix the starting symbol of the PUCCH resources and reduce the size of the PUCCH resources to a symbol length suitable for 2, which reschedules the PUCCH resources on

OFDM symbols

2 and 3 and prevents PUCCH resources having a lower priority from overlapping PUCCH resources having a higher priority.

PUCCH resources 16-80 for the long PUCCH may be assumed to be prioritized over PUCCH resources 16-70 for the long PUCCH. In this case, the terminal may move the scheduled PUCCH resources 16-70 on OFDM symbols 4 to 13 to a position available for transmission because PUCCH resources 16-70 have a lower priority. Here, the terminal may transmit corresponding UCI on PUCCH resources available for UL transmission in the next slot (slot #4) to prevent PUCCH resources having lower priority from overlapping PUCCH resources 16-80 scheduled on symbols 3 to 5 in slot #3 in the time domain. If the terminal determines that UCI scheduled on a PUCCH resource having a lower priority cannot be transmitted in slot #3, the terminal may discard the UCI transmission.

The terminal may modify the PUCCH format of the allocated PUCCH resources as denoted by reference numerals 16-70 in order to fix the starting symbol of the PUCCH resources and reduce the size of the PUCCH resources to a symbol length suitable for 10, which reschedules the PUCCH resources on OFDM symbols 6-13 and prevents PUCCH resources having a lower priority from overlapping PUCCH resources having a higher priority.

It can be assumed that two short PUCCH resources 16-90 and 16-100 are allocated for NC-JT and that PUCCH resource 16-90 takes precedence over PUCCH resource 16-100. In this case, the terminal may move the PUCCH resources 16-100 scheduled on

OFDM symbols

3 and 4 to a position available for UL transmission to transmit the corresponding UCI because the PUCCH resources 16-100 have a lower priority. If

symbols

6 and 7 are UL resources or resources that can be designated as UL resources, the terminal may move PUCCH resources 16-100 scheduled on

OFDM symbols

3 and 4 onto

OFDM symbols

6 and 7 in order to transmit corresponding UCI thereon. If

symbols

6 and 7 within slot # 3.

As described above, the terminal may adjust the starting position of the PUCCH resource having a lower priority to prevent the PUCCH resources for NC-JT from overlapping in the time domain. In this case, it is not necessary to modify the PUCCH format. An indicator value of a PUCCH resource having a lower priority may be adjusted to prevent overlapping of PUCCH resources for NC-JT. That is, a new PUCCH resource that does not overlap with a PUCCH resource having a higher high priority at a symbol level may be selected in the PUCCH resource set configured via RRC. In this case, it is not necessary to modify the PUCCH format.

Alternatively, it may be assumed that PUCCH resources 16-100 take precedence over PUCCH resources 16-90. In this case, the terminal may move the PUCCH resources 16-90 scheduled on

OFDM symbols

4 and 5 to a position available for UL transmission to transmit the corresponding UCI because the PUCCH resources 16-90 have a lower priority. Here, the terminal may move PUCCH resources 16-90 scheduled on

symbols

4 and 5 to

symbols

5 and 6 to prevent PUCCH resources having a lower priority from overlapping PUCCH resources 16-100 scheduled on

symbols

3 and 4 in the time domain. If

symbols

5 and 6 are DL resources or resources that may not be designated as UL resources, the terminal may transmit the corresponding UCI on the other two OFDM symbol resources available for UL transmission within slot #3 while maintaining a symbol length of 2 without any modification to the PUCCH format.

Examples 3 to 3:transmission based on PUCCH resource configuration of base station

The base station may configure two PUCCH resources for NC-JT to the terminal such that the PUCCH resources do not overlap in the time domain. As shown in table 8 and table 9, using the PUCCH resource indicator, the terminal may transmit UCI on a resource identified by a PUCCH resource ID in a PUCCH resource set configured via RRC. In this case, each code point for transmitting an indication from the TRP to the terminal is mapped to a corresponding PUCCH. Here, a large number of resource combinations are generated, and the base station may configure two PUCCH resources for NC-JT (which are separated in the time domain) to the terminal. However, PUCCH resources may also be configured to be separated in the frequency domain and/or in the spatial domain and in the time domain.

Fig. 18 illustrates a PUCCH resource configuration operation of a terminal according to an embodiment.

Referring to fig. 18, a base station may allocate PUCCH resources 18-04 for NC-JT in the form of PUCCH resource groups 18-05 and 18-55(PUCCH resource groups 18-05 and 18-55 are separated in the time domain) from two TRPs (TRP # 118-00 and TRP #218-02) to a terminal. The PUCCH resource groups may include PUCCH resources or PUCCH resource sets. The PUCCH resource groups may correspond to PUCCH resource sets. The PUCCH resource set may be interpreted as a resource in the form of a subgroup of PUCCH resource groups. PUCCH resources may be interpreted as elements of a PUCCH resource group. When allocated in units of subgroups (e.g., subgroups 18-10 and 18-12 and subgroups 18-60 and 18-62), the PUCCH resource groups 18-05 and 18-55 may be completely separated in the time domain. The PUCCH resource groups 18-05 and 18-55 may also be completely separated in the time domain when allocated in units of elements (e.g., element 18-10 and element 18-60). The PUCCH resources may be completely separated in the frequency domain. The above method may be applicable to resource allocation for transmission of individual HARQ-ACK/NACK payloads/feedback. PUCCH resources finally allocated to a terminal may be completely separated in the time domain and may or may not be completely separated in the frequency domain.

The base station may allocate PUCCH resources 18-06 for NC-JT in the form of PUCCH resource groups 18-15 and 18-75 from two TRPs to the terminal. The PUCCH resource groups may include PUCCH resources or PUCCH resource sets. The PUCCH resource groups may correspond to PUCCH resource sets. The PUCCH resource set may be interpreted as a resource in the form of a subgroup of PUCCH resource groups. PUCCH resources may be interpreted as elements of a PUCCH resource group. When allocated in units of subgroups, PUCCH resource groups may not be completely separated and may overlap in the time domain. When allocated in units of elements, PUCCH resource groups may not be completely separated and may overlap in the time domain. However, the base station may schedule the TRP having a coordinated configuration of (PUCCH resource group index of TRP #1, PUCCH resource group index of TRP #2) set to (18-20, 18-80), (18-20, 18-82), (18-22, 18-80), or (18-22, 18-82), so that the terminal individually identifies the resources. PUCCH resources allocated to the terminal may be completely separated in the frequency domain.

The base station may allocate to the terminal two PUCCH resources 18-25 per TRP and PUCCH resources 18-08 for NC-JT in the form of 18-95-PUCCH resource groups. The PUCCH resource groups may include PUCCH resources or PUCCH resource sets. The PUCCH resource groups may correspond to PUCCH resource sets. The PUCCH resource set may be interpreted as a resource in the form of a subgroup of PUCCH resource groups. PUCCH resources may be interpreted as elements of a PUCCH resource group. When allocated in units of subgroups, PUCCH resource groups that completely overlap in the time domain may not be individually identified. When allocated in units of elements, PUCCH resource groups that completely overlap in the time domain may or may not be individually identified. The base station may schedule the TRP having the coordinated configuration of (PUCCH resource element index of TRP #1, PUCCH resource element index of TRP #2) set to (18-30, 18-102) or (18-32, 18-100) so as to be individually identified in the time domain. Allocating resources for transmitting separate HARQ-ACK/NACK payloads/feedback increases scheduling complexity. The above described method may be suitable for allocating resources for a combined HARQ-ACK/NACK payload/feedback transmission. PUCCH resources allocated to a terminal may or may not be completely separated in the frequency domain.

Alternatively, PUCCH resources per TRP may be allocated such that TRPs are individually identified based on PUCCH spatial relationship information. During resource configuration of the base station, PUCCH spatial relationship information is associated with PUCCH resource ID, and if per TRP configuration is identified by the PUCCH spatial relationship information, TRP can be identified regardless of which code point of PUCCH resource indicator in DCI indicates TRP. By transmitting UCI having PUCCH spatial relationship information, PUCCH resources may be coordinated so as not to overlap in the time domain.

The base station may configure non-overlapping PUCCH resources during a PUCCH-Config configuration phase per TRP. PUCCH-Config may be used to configure PUCCH parameters per BWP for each terminal. PUCCH-Config may be used to add PUCCH resource sets and PUCCH resource set IDs; and adding, changing, or deleting PUCCH resources and PUCCH resource IDs, or changing the configuration of PUCCH format 1/2/3/4. Two PUCCH resources separated in the time domain may be configured for NC-JT.

The base station may individually configure PUCCH resource sets per TRP such that PUCCH resources do not overlap. As a result, the terminal can separately identify a PUCCH resource set composed of PUCCH resources for transmitting PUCCH in the time domain, such that resources indicated in each TRP resource set separated in the time domain do not overlap.

Terminals configured to receive NC-JT may not expect PUCCH resources configured according to various embodiments to overlap. The terminal may not expect the base station to configure any indication across the PUCCH resource subgroups or multiple indications for the same subgroup.

Although the above embodiments are directed to transmitting the HARQ-ACK codebook on PUCCH resources, the disclosed methods may also be applied to multiplexing and transmitting the HARQ-ACK codebook on PUCCH resources.

Although the above embodiments are directed to transmitting UCI on PUCCH resources that are HARQ-ACK codebooks, the disclosed methods may also be applied to transmitting UCI on PUCCH resources that include Scheduling Request (SR) or CSI and HARQ-ACK codebooks.

Fig. 19 illustrates a method for identifying a PUCCH corresponding to a PDCCH and a PUCCH resource per TRP scheduled by the PDCCH according to an embodiment.

Referring to fig. 19, during PDCCH scheduling, TRP # 119-00 may be configured with a PDCCH scheduling a PDSCH and a PUCCH corresponding to the PDSCH, as shown by reference numerals 19-20. Considering PUCCH resources, PUCCH resource sets, and PUCCH resource groups (e.g., as described above with reference to fig. 18), PDCCH #1 may include information for scheduling PUCCH # 1. If the PUCCH resource groups are multiplexed in a TDD manner, this may include the case when the PUCCH resource groups partially or entirely overlap.

PDCCH #1 of TRP # 119-00 is determined by CORESET and search space configuration in the frequency domain, and spatial configuration of CORESET for PDCCH can be determined by TCI state reference (reference) to DL RS # X, denoted by reference numerals 19-40. When DL RS # X is CSI-RS, the base station may use the parameter qcl-InfoPeriodicCSI-RS to reference TCI-StateID during NZP-CSI-RS-Rrsource configuration to the terminal via RRC message.

Reference numerals 19 to 40 denote that a TCI state reference operation is performed by referring to (refer) TCI-StateID in NZP-CSI-RS-Rrsource under the assumption that PDCCH and DL RS # x are quasi co-located (QCL) with each other. PDCCH #1 for TRP # 119-00 may be configured differently in the time and frequency domains, e.g., as described above with reference to fig. 18. The PUCCH can also be configured in the spatial domain in association with the DL-RS because the PUCCH spatial relationship information is configured in association with the DS-RS of the base station due to the nature of beamforming. Here, DS-RS X' may be RSs associated with various spatial domains (e.g., beam directions) understood by the base station for PUCCH transmission.

The PDCCH and PUCCH allocation and beamforming transmission may be determined according to the associations 19-45 between DL RS # X referenced in PDCCH #1 and DL RS # X' referenced according to the indication in the PUCCH spatial relationship information, as denoted by reference numerals 19-40. Associations 19-45 may be generated such that the base station associates two configuration values with each other. The method of generating the association may include configuring # X and # X 'to be equal so that DL RS # X and DL RS # X' become the same RS. The method of generating the association may further include setting # X and # X 'such that DL RS # X and DL RS # X' become reference signals of the QCL. That is, both the CORESET TCI state and the PUCCH spatial relationship information are referred to so that the PDCCH receiving direction and the PUCCH transmitting direction coincide.

The association of QCLs may be configured through CSI-RS resource settings and configuration of the base station via RRC messages, and updated via MAC CEs. The association of QCLs may be configured in association with defined QCL types A, B, C or D. As another example, the base station may adjust one of the two setting values according to a predetermined rule even if the two values do not match. If the two setting values do not match, this may be the case where DL RS # X and DL RS # X 'are the same RS, or the case where DL RS # X and DL RS # X' are not QCL with each other. One of the two values may be adjusted in such a manner that the base station and the terminal use one of the CORESET TCI status and the spatial relationship information of PDCCH #1 based on the same determination metric. For example, when the base station transmits an indication of NC-JT to the terminal based on multiple DCIs (e.g., multiple DCI based NCJT activation), the terminal may determine the PUCCH transmission direction based on the CORESET TCI state. The terminal may ignore the value of the PUCCH spatial relationship information. Although the above disclosed embodiments are referenced only for the CORESET TCI state, the spatial relationship information of the PUCCH may also be referenced.

The operations described in association with TRP # 119-00 can be applied to TRP # 219-50. PDCCH #2 and PUCCH #2 are correlated in the same manner as described above as denoted by reference numerals 19-60, and have correlations 19-85 denoted by reference numerals 19-80 in the same manner as described above with reference to CORESET TCI state and spatial relationship information correlated therewith. Here, also DL RS # Y and DL RS # Y' are referred to in the same manner as described above as denoted by reference numerals 19 to 80.

The base station can configure DL RS # X and DL RS # Y to be distinguished from each other by referring to the CORESET TCI state of TRP # 119-00 and the CORESET TCI state of TRP # 219-50. The base station transmits QCL configuration including information on reception beams carrying distinguished DL RSs (e.g., CSI RS, tracking RS (trs), and DM-RS) to the terminal. For example, if the DL RS is a CSI-RS, this may be indicated by TCI-StateID in NZP-CSI-RS-Resource using parameter qcl-InfoPeriodicCSI-RS during RRC configuration procedure. The receive beam information may be implicitly included or identified per TRP. If the configuration is received from the base station, the terminal can form a beam for transmitting UCI including HARQ-ACK to the TRP #1 and TRP #2 regardless of whether PUCCH resources, PUCCH resource sets, and PUCCH resource groups are partially/fully overlapped in time and frequency domains or multiplexed in TDM.

According to an embodiment, a method for configuring a HARQ-ACK codebook according to a time domain interval between PUCCH resources per TRP for NC-JT is provided.

Table 10 provides a method of configuring a type 1HARQ-ACK codebook or a type 2HARQ-ACK codebook according to a time interval between PUCCH resources per TRP.

[ TABLE 10 ]

In table 10, at least two different PUCCH resources for transmission to at least two different TRPs participating in multi-DCI based NC-JT are mapped to slots or OFDM symbols determined based on PUCCH resource indicator and PDSCH-to-HARQ feedback timing indicator field values included in the respective DCIs. Here, at least two different PUCCH resources for transmission to at least two different TRPs may be allocated to 1) different slots, 2) different OFDM symbols of the same slot, or 3) OFDM symbols including at least one OFDM symbol in which PUCCH resources overlap, or may be scheduled in the above-described 1) to 3). When different PUCCH resources are allocated to or scheduled in different OFDM symbols of the same slot or different slots, two different PUCCH resources are not allocated to or scheduled in the same OFDM symbol.

When different PUCCH resources for transmission to different TRPs are allocated to different slots or scheduled in different slots, both type 1HARQ-ACK codebook and type 2HARQ-ACK codebook may be supported according to the above method.

When different PUCCH resources for transmission to different TRPs are allocated to or scheduled in different OFDM symbols in the same slot, the base station and the terminal may define a sub-slot consisting of X (X <14) OFDM symbols. X may be preset to one value (e.g., 7) or one of a plurality of values (e.g., 2, 4, and 7) via a more layer configuration. In this case, considering the number of OFDM symbols (14 OFDM symbols) constituting a slot, X of the last sub-slot in the slot may be set to a value less than a preset value.

When PUCCH resources allocated to or scheduled in different OFDM symbols in the same slot are allocated to or scheduled in different sub-slots, at least one of a type 1HARQ-ACK codebook and a type 2HARQ-ACK codebook may be supported according to one of the following methods.

When sub-slot-based HARQ-ACK feedback is configured between a base station and a terminal, a unit counted in association with a counter DAI or a total DAI may be changed from a slot to a sub-slot to configure a type 2HARQ-ACK codebook.

As another example, the method may be modified for counting the maximum number of PDSCHs allocable within a slot between the base station and the terminal to configure a type 1HARQ-ACK codebook. For example, when sub-slot-based HARQ-ACK feedback is configured between the base station and the terminal, the "maximum number of PDSCHs allocable within a slot" may be changed to "maximum number of PDSCHs allocable (or allocated) within a corresponding sub-slot among PDSCHs allocable within a slot" to configure a type 1HARQ-ACK codebook. As another example, when sub-slot-based HARQ-ACK feedback is configured between a base station and a terminal, the "maximum number of PDSCH allocable within a slot" may be changed to "a maximum number of PDSCH schedulable by DCI transmitted in a specific PDCCH group among PDSCH allocable within a slot (or a maximum value, a minimum value, or an average value of the maximum number of schedulable PDSCH in case that the maximum numbers of DCI schedulable PDSCH transmitted in PDCCH groups are different from each other)" to configure a type 1HARQ-ACK codebook. In this embodiment, a CORESET may be understood as a set of one or more CORESETs per TRP, i.e., a set of CORESETs having the same activated TCI state.

When different PUCCH resources for transmission to different TRPs are allocated to or scheduled in an OFDM symbol including at least one OFDM symbol in which PUCCH resources overlap, the base station and the terminal may select one of PUCCH resources overlapping each other or a new PUCCH resource. The PUCCH resource selection may be performed by selecting a PUCCH resource indicated by DCI detected at the latest PDCCH monitoring opportunity among DCIs indicating PUCCH resources overlapping each other, or selecting a PUCCH resource using the highest transmission power or energy based on PUCCH power control.

After selecting PUCCH resources between the base station and the terminal, the terminal may generate and multiplex PDSCH HARQ-ACK feedback per TRP. Each TRP PDSCH HARQ-ACK feedback may be independently generated and serially concatenated or multiplexed according to one of the HARQ-ACK multiplexing methods described above.

Thereafter, the base station and the terminal may support at least one of a type 1HARQ-ACK codebook and a type 2HARQ-ACK codebook according to one of the following methods.

The terminal may count the counter DAI or total DAI of each CORESET group in order to configure the type 2HARQ-ACK codebook.

Alternatively, a method for counting the maximum number of PDSCHs allocable within a slot between a base station and a terminal may be modified so that the terminal configures a type 1HARQ-ACK codebook. For example, when HARQ feedback based on UCI multiplexing (or based on joint a/N feedback) is configured (or indicated) between the base station and the terminal, the terminal may change "the maximum number of PDSCHs allocable within a slot" to "the maximum number of PDSCHs schedulable by DCI transmitted in a specific PDCCH group among PDSCHs allocable within a slot (or the maximum value, the minimum value or the average value among them in the case where the maximum numbers of PDSCHs schedulable by DCI transmitted in a PDCCH group are different from each other)" in order to configure the type 1HARQ-ACK codebook. A CORESET may be understood as a set of one or more CORESETs per TRP, i.e. a set of CORESETs having the same activated TCI state.

Fig. 20 shows a terminal according to an embodiment.

Referring to fig. 20, the terminal includes a receiver 20-00, a transmitter 20-10, and a processor 20-05. The receiver 20-00 and the transmitter 20-10 may be collectively referred to as a transceiver. The receiver 20-00, the transmitter 20-10 and the processor 20-05 are operable to perform the above-described communication method. The configuration of the terminal is not limited to the components shown, but may be configured with more components (e.g., memory) or fewer components. The receiver 20-00, the transmitter 20-10 and the processor 20-05 may be integrated into a chip.

The receiver 20-00 and the transmitter 20-10 (or transceivers) may communicate signals with a base station. The signals may include control information and data. The transceiver may include a Radio Frequency (RF) transmitter for performing up-conversion and frequency amplification on a transmission signal, and an RF receiver for performing low-noise amplification and down-conversion on a reception signal. Further, the components of the transceiver are not limited to the RF transmitter and the RF receiver.

The transceiver may receive a signal through the radio channel and continue to transmit the signal to the processor 20-05 and transmit a signal output from the processor 20-05 through the radio channel.

The memory may store programs and data for operation of the terminal. The memory may also store control information or data acquired by the terminal. The memory may include one or a combination of storage media such as Read Only Memory (ROM), Random Access Memory (RAM), a hard disk, and compact disc read only memory (CD-ROM).

The processor 20-05 may control the overall operation of the terminal according to one of the disclosed embodiments. The processors 20-05 may be implemented as a controller or one or more processors.

Fig. 21 shows a base station according to an embodiment.

Referring to fig. 21, the base station includes a receiver 21-00, a transmitter 21-10, and a processor 21-05. The receiver 21-00 and the transmitter 21-10 may be collectively referred to as a transceiver. The receiver 21-00, the transmitter 21-10 and the processor 21-05 are operable to perform the above-described communication method. The configuration of the base station is not limited to the components shown, but may include more components (e.g., memory) or fewer components. The receiver 21-00, the transmitter 21-10 and the processor 21-05 may be integrated into a chip.

The receiver 21-00 and the transmitter 21-10 (or transceivers) may communicate signals with the terminals. The signals may include control information and data. The transceiver may include an RF transmitter for performing up-conversion and frequency amplification on a transmission signal, and an RF receiver for performing low-noise amplification and down-conversion on a reception signal. The components of the transceiver are not limited to RF transmitters and RF receivers.

The transceiver may receive signals over the radio channel and continue to transmit signals to the processor 21-05 and transmit signals output from the processor 21-05 over the radio channel.

The memory may store programs and data for operation of the base station. The memory may also store control information or data acquired by the base station. The memory may include one or a combination of storage media such as ROM, RAM, hard disk, and CD-ROM.

The processors 21-05 may control the overall operation of the base station in accordance with one of the disclosed embodiments. The processors 21-05 may be implemented as a controller or as one or more processors.

As described above, the provided methods and apparatuses are advantageous in facilitating signal transmission and reception by efficiently configuring a HARQ-ACK codebook between a terminal and a base station.

While the embodiments disclosed in the specification and drawings have been described using specific terms, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense, in order to facilitate an understanding of the present disclosure. The embodiments may be combined in whole or in part, if desired. For example, the disclosed

embodiments

1, 2 and 3 may be combined with each other, in part or in whole, to form embodiments for operation of the base station and the terminal. Further, it is apparent that part or all of the embodiments may be combined with part or all of another embodiment.

While the invention has been shown and described with reference to a particular embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and any equivalents thereof.

Size of bandwidth part

Configuration

Configuration 2

1. A method performed by a terminal in a wireless communication system, the method comprising:

receiving information configuring feedback of acknowledgement/negative acknowledgement (ACK/NACK) as separate feedback or joint feedback;

generating a first hybrid automatic repeat request acknowledgement (HARQ-ACK) codebook associated with a Physical Downlink Shared Channel (PDSCH) corresponding to a first control resource set (CORESET) having a first index value;

generating a second HARQ-ACK codebook associated with a PDSCH corresponding to a second CORESET having a second index value;

under the condition that the joint feedback is configured, acquiring HARQ-ACK information bits by serially connecting a second HARQ-ACK codebook behind a first HARQ-ACK codebook; and

transmitting the HARQ-ACK information bits in a Physical Uplink Control Channel (PUCCH).

2. The method of claim 1, wherein the HARQ-ACK information bits are transmitted in a PUCCH to a first Transmission and Reception Point (TRP) associated with a first CORESET or a second TRP associated with a second CORESET.

3. The method of claim 1, further comprising:

transmitting a first HARQ-ACK codebook based on Downlink Control Information (DCI) associated with a first CORESET if the individual feedback is configured; and

transmitting a second HARQ-ACK codebook based on the DCI associated with a second CORESET where the individual feedback is configured.

4. The method of claim 1, wherein a Physical Downlink Control Channel (PDCCH) monitoring opportunity of the first CORESET is indexed before a PDCCH monitoring opportunity of the second CORESET, and

wherein a serving cell of a HARQ-ACK codebook is counted twice, wherein a first time corresponds to the first CORESET and a second time corresponds to the second CORESET.

5. A method performed by a base station in a wireless communication system, the method comprising:

transmitting information configuring feedback of acknowledgement/negative acknowledgement (ACK/NACK) as separate feedback or joint feedback to a terminal; and

receiving hybrid automatic repeat request acknowledgement (HARQ-ACK) information bits from a terminal in a Physical Uplink Control Channel (PUCCH),

wherein, under the condition that the joint feedback is configured, HARQ-ACK information bits are obtained by connecting a second HARQ-ACK codebook in series after a first HARQ-ACK codebook,

wherein the first HARQ-ACK codebook is associated with a Physical Downlink Shared Channel (PDSCH) corresponding to a first control resource set (CORESET) having a first index value, and

wherein the second HARQ-ACK codebook is associated with a PDSCH corresponding to a second CORESET having a second index value.

6. The method of claim 5, wherein the base station is a first Transmission and Reception Point (TRP) of a terminal and the HARQ-ACK information bits are transmitted from the terminal to either a first TRP associated with a first CORESET or a second TRP associated with a second CORESET,

wherein the method further comprises: receiving a first HARQ-ACK codebook based on Downlink Control Information (DCI) associated with a first CORESET in a case where the individual feedback is configured, and

wherein the second HARQ-ACK codebook is transmitted from the terminal to the second TRP based on the DCI associated with the second CORESET in a case where the individual feedback is configured.

7. The method of claim 5, wherein a Physical Downlink Control Channel (PDCCH) monitoring opportunity of the first CORESET is indexed before a PDCCH monitoring opportunity of the second CORESET, and

8. A terminal in a wireless communication system, the terminal comprising:

a transceiver configured to transmit and receive signals; and

a controller configured to:

receiving information configuring feedback of acknowledgement/negative acknowledgement (ACK/NACK) as separate feedback or joint feedback,

generating a first hybrid automatic repeat request acknowledgement (HARQ-ACK) codebook associated with a Physical Downlink Shared Channel (PDSCH) corresponding to a first control resource set (CORESET) having a first index value,

generating a second HARQ-ACK codebook associated with a PDSCH corresponding to a second CORESET having a second index value,

obtaining HARQ-ACK information bits by concatenating a second HARQ-ACK codebook after the first HARQ-ACK codebook, with the joint feedback configured, an

9. The terminal of claim 8, wherein the HARQ-ACK information bits are transmitted in a PUCCH to a first Transmission and Reception Point (TRP) associated with a first CORESET or a second TRP associated with a second CORESET.

10. The terminal of claim 8, wherein the controller is further configured to:

a first HARQ-ACK codebook transmitted based on Downlink Control Information (DCI) associated with a first CORESET where the individual feedback is configured; and is

11. The terminal of claim 8, wherein a Physical Downlink Control Channel (PDCCH) monitoring opportunity of the first CORESET is indexed prior to a PDCCH monitoring opportunity of the second CORESET, and

12. A base station in a wireless communication system, the base station comprising:

a transceiver configured to transmit and receive signals; and

a controller configured to:

transmitting information configuring feedback of acknowledgement/negative acknowledgement (ACK/NACK) as separate feedback or joint feedback to the terminal, an

13. The base station of claim 12, wherein the base station is a first point of Transmission and Reception (TRP) of the terminal and the HARQ-ACK information bit is transmitted from the terminal to either a first TRP associated with a first CORESET or a second TRP associated with a second CORESET.

14. The base station of claim 12, wherein the controller is further configured to receive a first HARQ-ACK codebook based on Downlink Control Information (DCI) associated with a first CORESET if the individual feedback is configured, and

15. The base station of claim 12, wherein a Physical Downlink Control Channel (PDCCH) monitoring opportunity of the first CORESET is indexed prior to a PDCCH monitoring opportunity of the second CORESET, and