WO2023014169A1 - Method and device for performing retransmission on basis of harq process in wireless communication system - Google Patents

Abstract

The present invention relates to a method for performing HARQ retransmission by a terminal on the basis of NTN in a wireless communication system. The method may comprise the steps of: receiving from a base station an RRC message instructing either HARQ retransmission enable/disable; receiving CG configuration information from the base station; and performing data transmission on a CG resource instructed by means of the CG configuration information in accordance with either HARQ retransmission enable/disable.

Description

Method and apparatus for performing retransmission based on HARQ process in wireless communication system

The present invention relates to a method and apparatus for a terminal to perform retransmission based on a hybrid automatic repeat request (HARQ) process in a wireless communication system.

The present invention relates to a method for operating a configured grant timer (CGT) in a HARQ process based on non-terrestrial networks (NTN).

The International Telecommunication Union (ITU) is developing IMT (International Mobile Telecommunication) frameworks and standards, and recently, discussions for 5G communication are underway through a program called "IMT for 2020 and beyond" .

In order to meet the requirements presented by "IMT for 2020 and beyond", the 3rd Generation Partnership Project (3GPP) NR (New Radio) system considers various scenarios, service requirements, potential system compatibility, etc. It is being discussed in the direction of supporting various numerologies on a resource unit basis.

In addition, in the new communication system, mobile terminals (e.g. vehicle / train / ship type terminal / personal smartphone) using non-terrestrial networks (NTN) as well as terrestrial networks (TN) A discussion on how to support seamless communication service at the service level is underway, and the following describes a method of seamlessly providing service to terminals in a state where the NTN and terrestrial network service ranges overlap.

The present invention relates to a method and apparatus for performing retransmission based on an HARQ process in a wireless communication system.

The present invention relates to a method for operating a configured grant timer (CGT) based on an HARQ process in an NTN environment.

The present invention relates to a method for explicitly indicating whether HARQ retransmission is enabled.

The present invention relates to a method for implicitly indicating whether HARQ retransmission is enabled.

The present invention is a method for performing HARQ retransmission by a terminal based on NTN in a wireless communication system, comprising the steps of receiving an RRC message indicating whether HARQ retransmission is enabled from a base station, receiving CG configuration information from a base station, and HARQ and performing data transmission in a CG resource indicated through CG configuration information in consideration of whether retransmission is enabled. At this time, whether or not to enable HARQ retransmission is determined for each HARQ process, and if the HARQ process of the CG resource is HARQ retransmission enabled, CGT operates after data is transmitted in the CG resource, and a new HARQ process is used until the CGT expires. If data transmission is not performed and the HARQ process of the CG resource is HARQ retransmission disabled, CGT is not operated after data is transmitted in the CG resource, and new data transmission may be performed based on the HARQ process.

The features briefly summarized above with respect to the disclosure are merely exemplary aspects of the detailed description of the disclosure that follows, and do not limit the scope of the disclosure.

According to the present disclosure, a method for performing retransmission based on an HARQ process in a wireless communication system may be provided.

According to the present disclosure, it is possible to provide a method for operating a configured grant timer (CGT) based on an HARQ process in an NTN environment.

The present invention may provide a method for explicitly indicating whether HARQ retransmission is enabled.

The present invention may provide a method for implicitly indicating whether HARQ retransmission is enabled.

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

1 is a diagram for explaining an NR frame structure to which the present disclosure may be applied.

2 is a diagram showing a NR resource structure to which the present disclosure can be applied.

3 is a diagram illustrating an NTN including a transparent satellite to which the present disclosure can be applied.

4 is a diagram illustrating an NTN including a playback satellite without Inter-Satellite Links (ISL) to which the present disclosure can be applied.

5 is a diagram illustrating an NTN including a reproduction satellite in which an ISL to which the present disclosure can be applied is present.

6 is a diagram illustrating a user plane (UP) protocol stack structure in NTN including a transparent satellite to which the present disclosure can be applied.

7 is a diagram illustrating a control plane (CP) protocol stack structure in NTN including a transparent satellite to which the present disclosure can be applied.

8 is a diagram illustrating a timing advance calculation method to which the present disclosure may be applied.

9 is a diagram illustrating an earth fixed cell scenario to which the present disclosure may be applied.

10 is a diagram illustrating an earth moving cell scenario to which the present disclosure can be applied.

11 is a diagram illustrating a method of mapping PCI to satellite beams to which the present disclosure can be applied.

12 is a diagram illustrating a HARQ process configuration to which the present disclosure can be applied.

13 is a diagram illustrating a method of performing CG retransmission based on a CG HARQ process and CGT to which the present disclosure can be applied.

14 is a diagram illustrating a method in which a UE to which the present disclosure can be applied performs new transmission based on a PDCCH scrambled with a C-RNTI.

15 is a diagram illustrating a CGT operation method based on enabling/disabling HARQ retransmission to which the present disclosure may be applied.

16 is a diagram illustrating HARQ retransmission enable/disable based CG configuration and procedures between a terminal and a base station to which the present disclosure can be applied.

17 is a diagram illustrating a method of implicitly indicating whether to enable/disable HARQ retransmission to which the present disclosure can be applied.

18 is a diagram illustrating a method of implicitly indicating HARQ retransmission enable/disable to which the present disclosure may be applied.

19 is a diagram illustrating a new timer to which the present disclosure can be applied.

20 is a flowchart illustrating a method of explicitly indicating whether to enable/disable HARQ retransmission to which the present disclosure can be applied.

21 is a flowchart illustrating a method of implicitly indicating whether to enable/disable HARQ retransmission to which the present disclosure can be applied.

22 is a diagram showing a device configuration to which the present disclosure can be applied.

Hereinafter, with reference to the accompanying drawings, embodiments of the present disclosure will be described in detail so that those skilled in the art can easily implement the present disclosure. However, this disclosure may be embodied in many different forms and is not limited to the embodiments set forth herein.

In describing the embodiments of the present disclosure, if it is determined that a detailed description of a known configuration or function may obscure the gist of the present disclosure, a detailed description thereof will be omitted. And, in the drawings, parts irrelevant to the description of the present disclosure are omitted, and similar reference numerals are assigned to similar parts.

In the present disclosure, when a component is said to be "connected", "coupled" or "connected" to another component, this is not only a direct connection relationship, but also an indirect connection relationship where another component exists in the middle. may also be included. In addition, when a component "includes" or "has" another component, this means that it may further include another component without excluding other components unless otherwise stated. .

In the present disclosure, terms such as first and second are used only for the purpose of distinguishing one element from another, and do not limit the order or importance of elements unless otherwise specified. Accordingly, within the scope of the present disclosure, a first component in one embodiment may be referred to as a second component in another embodiment, and similarly, a second component in one embodiment may be referred to as a first component in another embodiment. can also be called

In the present disclosure, components that are distinguished from each other are intended to clearly explain each characteristic, and do not necessarily mean that the components are separated. That is, a plurality of components may be integrated to form a single hardware or software unit, or a single component may be distributed to form a plurality of hardware or software units. Accordingly, even such integrated or distributed embodiments are included in the scope of the present disclosure, even if not mentioned separately.

In the present disclosure, components described in various embodiments do not necessarily mean essential components, and some may be optional components. Accordingly, an embodiment comprising a subset of elements described in one embodiment is also included in the scope of the present disclosure. In addition, embodiments including other components in addition to the components described in various embodiments are also included in the scope of the present disclosure.

The present disclosure describes a wireless communication network, and operations performed in the wireless communication network are performed in the process of controlling the network and transmitting or receiving signals in a system (for example, a base station) that manages the wireless communication network, or It may be performed in a process of transmitting or receiving a signal from a terminal coupled to a wireless network.

It is obvious that various operations performed for communication with a terminal in a network composed of a plurality of network nodes including a base station may be performed by the base station or other network nodes other than the base station. 'Base Station (BS)' may be replaced by terms such as fixed station, Node B, eNodeB (eNB), ng-eNB, gNodeB (gNB), and access point (AP). . In addition, 'terminal' will be replaced with terms such as User Equipment (UE), Mobile Station (MS), Mobile Subscriber Station (MSS), Subscriber Station (SS), and non-AP STA. can

In the present disclosure, transmitting or receiving a channel means transmitting or receiving information or a signal through a corresponding channel. For example, transmitting a control channel means transmitting control information or a signal through the control channel. Similarly, transmitting a data channel means transmitting data information or a signal through the data channel.

In the following description, the term NR (New Radio) system is used for the purpose of distinguishing a system to which various examples of the present disclosure are applied from an existing system, but the scope of the present disclosure is not limited by these terms. .

The NR system supports various subcarrier spacing (SCS) considering various scenarios, service requirements, and potential system compatibility. In addition, the NR system uses multiple channels to overcome poor channel environments such as high path-loss, phase-noise, and frequency offset occurring on a high carrier frequency. It is possible to support transmission of a physical signal / channel through a beam of. Through this, the NR system can support applications such as eMBB (enhanced mobile broadband), mMTC (massive machine type communications)/uMTC (ultra machine type communications), and URLLC (ultra reliable and low latency communications).

Hereinafter, 5G mobile communication technology may be defined to include not only the NR system, but also the existing Long Term Evolution-Advanced (LTE-A) system and Long Term Evolution (LTE) system. 5G mobile communication may include a technology that operates in consideration of backward compatibility with the previous system as well as the newly defined NR system. Therefore, the following 5G mobile communication may include a technology operating based on the NR system and a technology operating based on the previous system (e.g., LTE-A, LTE), and is not limited to a specific system.

First, the physical resource structure of the NR system to which the present invention is applied will be briefly described.

1 is a diagram for explaining an NR frame structure to which the present disclosure may be applied.

일 수 있고,

이고, N=4096일 수 있다. 한편, LTE에서 시간 도메인 기본 단위는

일 수 있고,

이고,

=2048일 수 있다. NR 시간 기본 단위와 LTE 시간 기본 단위 사이의 배수 관계에 대한 상수는 k=

로서 정의될 수 있다.The basic unit of the time domain in NR is

can be,

, and may be N = 4096. On the other hand, in LTE, the time domain basic unit is

can be,

ego,

=2048. The constant for the multiple relationship between the NR time base unit and the LTE time base unit is k=

can be defined as

를 가질 수 있다. 여기서, 하나의 프레임은

시간에 해당하는 10개의 서브프레임으로 구성된다. 서브프레임마다 연속적인 OFDM 심볼의 수는

=

일 수 있다. 또한, 각 프레임은 동일한 크기의 2개의 하프 프레임(half frame)으로 나누어지며, 하프 프레임 1은 서브 프레임 0-4로 구성되고, 하프 프레임 2는 서브 프레임 5-9로 구성될 수 있다.Referring to FIG. 1, the time structure of a frame for downlink/uplink (DL/UL) transmission is

can have Here, one frame

It consists of 10 subframes corresponding to time. The number of consecutive OFDM symbols per subframe is

=

can be In addition, each frame is divided into two half frames of the same size, half frame 1 may be composed of subframes 0-4, and half frame 2 may be composed of subframes 5-9.

는 하향링크(DL)와 상향링크(UL) 간의 타이밍 어드밴스(TA)를 나타낸다. 여기서, 상향링크 전송 프레임 i의 전송 타이밍은 단말에서 하향링크 수신 타이밍을 기반으로 아래의 수학식 1에 기초하여 결정된다.

represents a timing advance (TA) between downlink (DL) and uplink (UL). Here, the transmission timing of the uplink transmission frame i is determined based on Equation 1 below based on the downlink reception timing at the terminal.

[Equation 1]

은 듀플렉스 모드 (duplex mode) 차이 등으로 발생하는 TA 오프셋 (TA offset) 값일 수 있다. FDD (Frequency Division Duplex)에서

은 0 값을 가지지만, TDD (Time Division Duplex)에서는 DL-UL 스위칭 시간에 대한 마진을 고려해서

의 고정된 값으로 정의될 수 있다. 일 예로, 서브 6GHz이하 주파수인 FR1(Frequency Range 1)의 TDD(Time Division Duplex)에서

는 39936

또는 25600

일 수 있다. 39936

는 20.327μs이고, 25600

는 13.030μs이다. 또한, 밀리미터파(mmWave) 주파수인 FR2(Frequency Range 2)에서

는 13792

일 수 있다. 이때, 13792

는 7.020 μs이다.here,

may be a TA offset value generated by a duplex mode difference or the like. In frequency division duplex (FDD)

has a value of 0, but in TDD (Time Division Duplex), considering the margin for DL-UL switching time

can be defined as a fixed value of For example, in Time Division Duplex (TDD) of Frequency Range 1 (FR1), which is a sub-6 GHz frequency

is 39936

or 25600

can be 39936

is 20.327 μs, 25600

is 13.030 μs. In addition, in the mmWave frequency FR2 (Frequency Range 2)

is 13792

can be At this time, 13792

is 7.020 μs.

2 is a diagram showing a NR resource structure to which the present disclosure can be applied.

A resource element (RE) in a resource grid may be indexed according to each subcarrier spacing. Here, one resource grid may be generated for each antenna port and each subcarrier spacing. Uplink and downlink transmission and reception may be performed based on a corresponding resource grid.

는 하나의 RB 당 서브캐리어의 개수를 의미하고, k는 서브캐리어 인덱스를 의미한다.One resource block (RB) in the frequency domain is composed of 12 REs, and an index (nPRB) for one RB may be configured for each 12 REs. An index for an RB may be utilized within a specific frequency band or system bandwidth. An index for RB may be defined as in Equation 2 below. here,

denotes the number of subcarriers per one RB, and k denotes a subcarrier index.

[Equation 2]

Various numerologies can be set to satisfy various services and requirements of the NR system. For example, one subcarrier spacing (SCS) can be supported in an LTE/LTE-A system, but a plurality of SCSs can be supported in an NR system.

A new numerology for NR systems supporting multiple SCS is 3 GHz or less, 3 GHz-6 GHz to solve the problem of not being able to use a wide bandwidth in a carrier or frequency range such as 700 MHz or 2 GHz. , 6GHZ-52.6GHz or 52.6GHz and above.

Table 1 below shows examples of numerologies supported by the NR system.

[Table 1]

Referring to Table 1, the numerology may be defined based on subcarrier spacing (SCS) used in an orthogonal frequency division multiplexing (OFDM) system, cyclic prefix (CP) length, and the number of OFDM symbols per slot. The values may be provided to the UE through higher layer parameters DL-BWP-mu and DL-BWP-cp for downlink and UL-BWP-mu and UL-BWP-cp for uplink. .

In Table 1, when the subcarrier spacing setting index u is 2, the subcarrier spacing Δf is 60 kHz, and a normal CP and an extended CP may be applied. In the case of other numerology indexes, only normal CP can be applied.

A normal slot can be defined as a basic time unit used to transmit basically one piece of data and control information in an NR system. The length of a normal slot can be set to the number of 14 OFDM symbols by default. In addition, unlike a slot, a subframe has an absolute time length corresponding to 1 ms in the NR system and can be used as a reference time for the length of other time intervals. Here, for coexistence or backward compatibility between the LTE system and the NR system, a time interval such as a subframe of LTE may be required in the NR standard.

For example, in LTE, data may be transmitted based on a transmission time interval (TTI), which is a unit time, and the TTI may be set in units of one or more subframes. Here, one subframe may be set to 1 ms and may include 14 OFDM symbols (or 12 OFDM symbols).

Also, non-slots may be defined in NR. A non-slot may mean a slot having a number smaller than that of a normal slot by at least one symbol. For example, in the case of providing a low delay time such as URLLC service, the delay time can be reduced through non-slots having a smaller number of symbols than normal slots. Here, the number of OFDM symbols included in the non-slot may be determined in consideration of a frequency range. For example, in a frequency range of 6 GHz or higher, a non-slot having a length of 1 OFDM symbol may be considered. As a further example, the number of OFDM symbols defining a non-slot may include at least two OFDM symbols. Here, the range of the number of OFDM symbols included in the non-slot may be set as a mini-slot length up to a predetermined length (eg, normal slot length -1). However, as a non-slot standard, the number of OFDM symbols may be limited to 2, 4 or 7 symbols, but is not limited thereto.

In addition, for example, subcarrier spacings corresponding to u equal to 1 and 2 are used in unlicensed bands below 6 GHz, and subcarrier spacings corresponding to u equal to 3 and 4 may be used in unlicensed bands exceeding 6 GHz. For example, when u is 4, it may be used for SSB (Synchronization Signal Block).

[Table 2]

), 프레임 당 슬롯 개수(

), 서브프레임 당 슬롯의 개수(

)를 나타낸다. 표 2에서는 14개의 OFDM 심볼을 갖는 노멀 슬롯을 기준으로 상술한 값들을 나타낸다.Table 2 shows the number of OFDM symbols per slot in the case of a normal CP for each subcarrier spacing setting (u) (

), the number of slots per frame (

), the number of slots per subframe (

). Table 2 shows the above-described values based on a normal slot having 14 OFDM symbols.

[Table 3]

Table 3 shows the number of slots per frame and the number of slots per subframe based on the normal slot where the number of OFDM symbols per slot is 12 when the extended CP is applied (ie, when u is 2 and the subcarrier spacing is 60 kHz). represents the number of

As described above, one subframe may correspond to 1 ms on the time axis. Also, one slot may correspond to 14 symbols on the time axis. For example, one slot may correspond to 7 symbols on the time axis. Accordingly, the number of slots and symbols that can be considered can be set differently within 10 ms corresponding to one radio frame. Table 4 may indicate the number of slots and symbols according to each SCS. In Table 4, SCS of 480 kHz may not be considered, but is not limited to these examples.

[Table 4]

Also, for example, in an existing wireless communication system, communication may be performed based on a terrestrial network composed of terminals located on the ground and base stations located on the ground. The terminal may access the network through wireless. Here, when the terminal moves, the terminal may be provided with the same service continuously through other base stations in the terrestrial network. After accessing the network, the terminal was able to access a specific service server through other wired or Internet networks. In addition, the terminal could be provided with a service for connecting wired or wireless communication with other terminals through the network.

However, in a new wireless communication system, communication of a terminal may be supported through not only a terrestrial network but also a non-terrestrial network (NTN). Here, NTN may refer to a network or part of a network using a mobile body floating in the air or space equipped with a base station or relay equipment. For example, the NTN may support a communication service between terminals based on satellites equipped with communication functions on Low Earth Orbit (LEO) and Geostationary Earth Orbit (GEO). As another example, the NTN may support a communication service between terminals based on an aircraft equipped with a communication function in an unmanned aircraft system (UAS), but is not limited thereto.

In the following, terrestrial networks (TN) are distinguished and described in contrast to non-terrestrial networks (NTN). That is, since only terrestrial networks exist in existing communication systems, they cannot be distinguished. On the other hand, in the following, NTN and TN are distinguished and described as a communication system capable of communication between terminals based on NTN, and a method of supporting communication service between terminals based thereon is described.

For example, a wireless communication service between a terrestrial base station and a wireless terminal or between a mobile base station is described as a mobile service, but is not limited thereto. Also, communication between the mobile terrestrial base stations and one or more space base stations may be a mobile satellite service. In addition, a wireless communication service between mobile terrestrial base stations and space base stations or between mobile terrestrial base stations through at least one space base station may also be a mobile satellite service, but is not limited thereto.

In the following, a method of performing communication based on a wireless communication system supporting both a mobile service and a mobile satellite service will be described. For example, technologies for NTN have been introduced to be specialized for satellite communication, but NTN can also be introduced in TN's communication system (e.g. 5G system) to operate like TN. Here, the UE can simultaneously support NTN and TN. The wireless communication system may require specific technologies for NTN in addition to long-term evolution (LTE) and new radio (NR) systems, which are radio access technology (RAT), for a terminal that supports both NTN and TN at the same time. , a method for this is described below. As an example, the following may be definitions for each term in relation to NTN and TN.

Non-terrestrial networks (NTN):

A network or part of a network using a mobile vehicle in the air or in space equipped with a base station or relay equipment for communication.

NTN-gateway:

A terrestrial base station or gateway located on the surface of the earth and equipped with sufficient radio access equipment to access satellites. In general, an NTN gateway may be a transport network layer node (TNL).

Feeder link:

Radio link between NTN gateway and satellite

Geostationary Earth orbit (GEO):

A circular orbit 35,786 km above the Earth's equator that coincides with the direction of Earth's rotation. Objects or satellites in the orbit orbit at the same period as the Earth's rotation period. Therefore, when observed from Earth, it appears to exist in a fixed position without movement.

Low Earth Orbit (LEO):

Orbits between 300 km and 1500 km above

Medium Earth Orbit (MEO):

Orbits existing between LEO and GEO

Unmanned Aircraft Systems (UAS):

A system that typically operates at 8 km to 50 km above ground and may include High Altitude Platforms (HAPs). The unmanned aerial vehicle system may include at least one or more of a Tethered UAS (TUA), a Lighter Than Air UAS (LTA), and a Heavier Than Air UAS (HTA) system.

Minimum Elevation angle:

The minimum angle required for a ground terminal to face a satellite or UAS base station in the air

Mobile Services:

Wireless communication service between terrestrial base stations and wireless terminals or between mobile base stations

Mobile Satellite Services:

It may be a wireless communication service between mobile terrestrial base stations and one or more space base stations, or between mobile terrestrial base stations and space base stations, or between mobile terrestrial base stations via one or more space base stations.

Non-Geostationary Satellites:

Satellites in LEO and MEO orbits may be satellites orbiting the Earth with a period of between about 1.5 and 10 hours.

On Board processing:

Digital processing of uplink RF signals mounted on satellites or non-terrestrial equipment

Transparent payload:

It may mean changing the carrier frequency of an uplink RF signal and filtering and amplifying it before transmitting it through downlink.

Regenerative payload:

Transformation and amplification of uplink RF signals before transmission through downlink. Signal transformation may include digital processing such as decoding, demodulation, re-modulation, re-encoding, and filtering.

On board NTN gNB:

It may refer to an on-board satellite in which a base station (gNB) is implemented in a regenerative payload structure.

On ground NTN gNB:

A terrestrial base station implemented with a base station (gNB) in a transparent payload structure

One-way latency:

The time required to reach a wireless terminal from a wireless terminal to a public data network or from a public data network to a wireless terminal in a wireless communication system.

Round Trip Delay (RTD):

It can be the time when any signal travels from the wireless terminal to the NTN-gateway or from the NTN-gateway to the wireless terminal and back again. At this time, the returned signal may be a signal including a different form or message from the above arbitrary signal.

Satellite:

It may be a mobile vehicle in space equipped with a wireless communication transceiver capable of supporting a transparent payload or a regenerative payload, and may be generally located on LEO, MEO, or GEO orbits.

Satellite beam:

The beam produced by the onboard satellite's antenna

Service link:

Radio link between satellite and terminal (UE)

User Connectivity:

Ability to establish and maintain data/voice/video transmission between network and terminal

User Throughput:

Data transmission rate provided to the terminal

3 is a diagram illustrating an NTN including a transparent satellite to which the present disclosure can be applied.

Referring to FIG. 3, a terminal included in the NTN may include a terrestrial network terminal. For example, NTN and TN terminals may include manned or unmanned vehicles such as ships, trains, buses, or airplanes, and may not be limited to a specific form. Referring to FIG. 3 , a transparent satellite payload generated through a network including transparent satellites may be implemented in a manner corresponding to an RF repeater.

More specifically, a network including transparent satellites may perform frequency conversion and amplification of radio signals received in all directions of uplink and downlink, and transmit the radio signals. Accordingly, the satellite may perform a function of relaying the NR-Uu air interface including both the feeder link and the service link, and the NR-Uu air interface will be described later.

As another example, referring to FIG. 3 , a satellite radio interface (SRI) on a feeder link may be included in an NR-Uu interface. That is, the satellite may not be the end of the NR-Uu interface. Here, the NTN gateway can support all functions required to deliver signals defined in the NR-Uu interface. For example, different transparent satellites may be connected to the same base station on the ground. That is, a configuration in which a plurality of transparent satellites are connected to one terrestrial base station may be possible. The base station may be an eNB or a gNB, but may not be limited to a specific form.

4 is a diagram illustrating an NTN including a playback satellite without Inter-Satellite Links (ISL) to which the present disclosure can be applied.

Referring to FIG. 4, NTN may include playback satellites. Here, the reproduction satellite may mean that a base station function is included in the satellite. For example, a reproduction satellite payload generated through a network including reproduction satellites may be implemented by regenerating a signal received from the ground.

More specifically, the playback satellite may receive a signal from the ground based on an NR-Uu air interface on a service link between the terminal and the satellite. As another example, the reproduction satellite may receive a signal from the ground through a satellite radio interface (SRI) on a feeder link between NTN gateways. Here, Satellite Radio Interface (SRI) may be defined in a transport layer between a satellite and an NTN gateway. A transport layer may mean a transport layer among layers defined as OSI 7 layers. That is, a signal from the ground based on a reproduction satellite may be transformed based on digital processes such as decoding, demodulation, re-modulation, re-encoding and filtering, but not limited thereto.

5 is a diagram illustrating an NTN including a reproduction satellite in which an ISL to which the present disclosure can be applied is present.

Referring to FIG. 5, ISL may be defined in the transport layer. As another example, the ISL may be defined as a radio interface or a visible light interface, and is not limited to a specific embodiment. Here, the NTN gateway can support all functions of the transport protocol. In addition, each playback satellite can be a base station, and multiple playback satellites can be connected to the same 5G core network on the ground.

6 is a diagram illustrating a user plane (UP) protocol stack structure in NTN including a transparent satellite to which the present disclosure can be applied. 7 is a diagram illustrating a control plane (CP) protocol stack structure in NTN including a transparent satellite to which the present disclosure can be applied.

The NR Uu interface may be an interface defined by protocols for wireless access between a terminal and a base station in the NR system. In this case, the NR Uu interface may include a user plane defined by protocols for user data transmission including NTN. In addition, the NR Uu interface may include a control plane defined by protocols for transmitting signaling including RRC information including NTN. For example, the Medium Access Control (MAC) layer includes Radio Link Control (RLC), Packet Data Convergence Protocol (PDCP), and Service Data Adaptation Protocol (SDAP). ) and Radio Resource Control (RRC), and the protocol for each layer may be defined based on NR among 3GPP RAN-related standards, but may not be limited thereto.

As an example, FIG. 6 may be a UP protocol stack structure based on a transparent satellite. That is, in the satellite and NTN gateways, only frequency conversion and amplification of the radio signal received transparently can be performed and transmitted. Also, FIG. 7 may be a CP protocol stack structure based on a transparent satellite. That is, in the satellite and NTN gateways, only frequency conversion and amplification of radio signals received transparently can be performed.

Based on the foregoing, it is possible to consider a wireless communication system supporting terminal-to-device communication with NTN and TN. Here, as an example, the roundtrip time (RTT) between the terminal and the base station may be greater in the NTN than in the existing TN. Accordingly, the UE needs to store data to be transmitted through each of uplink and downlink in a buffer for a longer period of time due to an increase in RTT from a UP point of view. That is, the terminal needs to store more data in the buffer. Accordingly, the terminal may require a memory having a larger capacity than before, which will be described later.

8 is a diagram illustrating a timing advance calculation method to which the present disclosure may be applied. As described above, since satellites included in NTN are located in the sky, signal round-trip time (RTT) may be long. For example, in the case of LEO, it exists at an altitude of 300 km to 1200 km, and in the case of GEO, it may be located at 36,000 km or more above the equator. Therefore, in NTN, propagation delay can be very large compared to TN. On the other hand, since NTN is located in the sky, cell coverage may be greater than that of terrestrial networks.

That is, since the NTN may have different RTT and cell coverage compared to the TN, there is a need to newly define a method for obtaining time synchronization for uplink transmission in the NTN. As an example, FIG. 8 may be a method of calculating a TA value generated according to a satellite payload type.

More specifically, FIG. 8(a) may be a method of calculating a TA value when a satellite payload type is a reproduced payload. Also, FIG. 8(b) may be a method of calculating a TA value when a satellite payload type is a transparent payload.

Here, a case in which the terminal knows the satellite ephemeris and the location of the terminal may be considered for initial access and continuous maintenance of a timing advance (TA) value. Here, the satellite ephemeris may mean a distance between each satellite and a receiver and position information of each satellite. As an example, the UE can acquire and apply the TA value by itself. (Option 1 below). As another example, the UE can receive instructions for TA compensation and correction from the network. (Option 2 below)

For example, referring to FIG. 8(a) , when the satellite payload type is a replay payload, the satellite may directly serve as a base station. At this time, the UE may calculate a TA value required for uplink transmission including a physical random access channel (PRACH). The UE may calculate a common TA value (Tcom) and a TA value (TUEx) for each UE. As an example, the common TA value (Tcom) may be a TA value required for all terminals occurring with large cell coverage of NTN and long round trip time (RTT). That is, since the NTN is located in the sky and has a relatively longer distance than the distance between terminals, a common TA value (Tcom) considering a long round-trip time (RTT) in cell coverage may be required. In addition, the TA value (TUEx) for each UE may be a value generated due to different locations of each UE within cell coverage. If the terminal pre-stored or received the ephemeris from the NTN to determine the position of the satellite at a specific time and knows the location of the corresponding terminal through a function such as GNSS, the terminal can locate the satellite at a specific time Since the distance between the terminal and the terminal can be calculated, the TA value can be corrected after acquiring the TA value by itself, and the TA value can be determined through this.

Through the above, the UE can perform uplink timing alignment between UEs received from the base station with full TA compensation.

As another example, the terminal may perform downlink and uplink frame timing alignment at the network side. As shown in FIG. 8( b ), when the satellite payload type is the transparent payload, the satellite performs filtering and amplification of the radio signal and transmits the signal to the NTN gateway. That is, the satellite can operate like an RF repeater. At this time, a case may occur in which the NTN gateway needs to be changed based on the continuous movement of the satellite. In FIG. 8(b), the common TA value Tcom may be determined based on the sum of the distance D01 between the reference point and the satellite and the distance D02 between the satellite and the NTN gateway. In this case, the feeder link may be changed according to the change of the NTN gateway based on the movement of the satellite. That is, the distance between the satellite and the NTN gateway may be changed based on the changed feeder link. Therefore, the generated common TA value may be changed, and there is a need for updating in the corresponding terminal. In addition, when setting an offset between downlink frame timing and uplink frame timing in a network, there is a need to additionally consider a case in which a TA value generated due to feeder link is not corrected by the entire TA compensation method. In addition, when the terminal can calculate only different TA values (TUEx) for each terminal, the terminal needs to check one reference point for each beam or cell, and transmits information about this to other terminals. There is a need. When an offset is set between downlink frame timing and uplink frame timing in a network, the network needs to manage offset information regardless of satellite payload type. Here, as an example, the network may provide a value for TA correction to each terminal, and is not limited to the above-described embodiment.

As another example, a method for instructing TA compensation and correction in the network (option 2) may be considered. In this case, a common TA value may be generated based on common elements of propagation delay shared by all terminals located within the satellite beam or cell coverage. The network may transmit a common TA value to UEs for each beam or cell of each satellite based on a broadcast method. The common TA value may be calculated in the network assuming at least one reference location for each beam or cell of each satellite. In addition, the TA value (TUEx) for each UE may be determined based on a random access procedure defined in the existing communication system (eg, Release 15 or Release 16 of the existing NR system). In this case, for example, when a long TA value and a negative TA value are applied, a new field may be required for the random access message. For example, when a timing change rate is provided to a UE by a network, the UE may support TA value correction based on the timing change rate.

9 is a diagram illustrating an earth fixed cell scenario to which the present disclosure may be applied.

Referring to FIG. 9 , a fixed cell may be a cell in which a signal transmission location from a satellite is fixed. For example, since a satellite moves according to time, a fixed cell can be maintained only when a service coverage is fixed to a specific location by changing an antenna and a beam. In this case, for example, satellite 1 910 in FIG. 9 may maintain a fixed cell while changing an antenna and a beam during T1 to T3. Here, when a specific time (T4) elapses, since satellite 1 can no longer service the corresponding location, satellite 2 920 provides service at the corresponding location, thereby maintaining service continuity. At this time, after time T4, the beam or cell of satellite 2 (920) serving the same position as the position serviced by satellite 1 (910) at the previous time (T1 to T3) is the beam or cell of satellite 1 (910). characteristics can be maintained, and is not limited to the above-described embodiment.

As a more specific example, when services are provided to satellite 1 910 and satellite 2 920, at least one of a physical cell ID (PCI) value and system information may remain the same. That is, as a cell with fixed service coverage, it can be set based on satellites whose antenna and beam angle can be varied among satellites on LEO and MEO orbits, except for GEO.

On the other hand, FIG. 10 is a diagram illustrating an earth moving cell scenario to which the present disclosure can be applied. For example, a cell in which service coverage moves may be an earth moving cell.

For example, referring to FIG. 10 , satellite 1 (1010), satellite 2 (1020), and satellite 3 (1030) may provide services to respective cells having different PCIs. In this case, an antenna and a beam through which the satellite transmits a signal to the ground are fixed, and a form in which service coverage moves as the satellite moves over time may be referred to as an earth moving cell. The terrestrial mobile cell may be set based on satellites having fixed antenna and beam angles among satellites on LEO and MEO orbits, except for GEO. Here, the corresponding satellites may have advantages of low cost and low failure rate compared to satellites capable of adjusting the angle of an antenna and a beam.

11 is a diagram illustrating a method of mapping PCI to satellite beams to which the present disclosure can be applied.

For example, PCI may refer to an index capable of logically distinguishing one cell. That is, beams having the same PCI value may be included in the same cell. For example, referring to FIG. 11(a), PCI may be allocated to several satellite beams. On the other hand, referring to FIG. 11(b), one PCI may be assigned to each satellite beam in one satellite. For example, a satellite beam may be composed of one or more SSB (Synchronization Signal Block, SS/PBCH block) beams. One cell (or PCI) may consist of up to L SSB beams. Here, L may be 4, 8, 64, or 256 according to the size of the frequency band and/or subcarrier band, but is not limited to the above-described embodiment. That is, in L, similar to a terrestrial network (TN), which is an existing communication system (NR system), one or several SSB indexes may be used for each PCI. Through this, SSBs transmitted through different beams can be distinguished, and an SSB index can be mapped with a logically defined antenna port or a physically separated beam.

For example, a terminal capable of accessing NTN may be a terminal supporting a Global Navigation Satellite System (GNSS) function. However, terminals capable of accessing NTN may include terminals that do not support GNSS. As another example, the NTN can also support a terminal that supports a GNSS function but cannot secure location information through GNSS, and is not limited to the above-described embodiment.

As described above, the terminal may perform communication through NTN. For example, a terminal may receive a 5G/B5G NTN-based non-terrestrial network-based service. Through this, the terminal can escape from regional, environmental, spatial and economic constraints on wireless access services (e.g., LTE, NR, WiFi, etc.) based on ground network equipment installation. For example, based on the above, an advanced radio access technology provided on a terrestrial network may be applicable to non-terrestrial network platforms (e.g., satellites and UAVs). Through this, various radio access service products and technologies can be provided together with advanced network technologies.

The NTN platform can be operated as a kind of mirror by installing a function of relaying NR signals in space or at high altitudes or a function of a base station (gNB, eNB). As an example, the NG-RAN based NTN architecture, as already mentioned, can be implemented with "Transparent payload-based NTN" and "Regenerative payload-based NTN" structures, which are as described above.

In addition, as an example, NTN technology can be used for wider coverage and more radio access services as an extended network structure and technology of 5G IAB (Integrate Access and Backhaul) architecture. Integration of NTN and terrestrial networks can ensure service continuity and scalability of 5G systems.

As a specific example, NTN and TN convergence networks can provide significant gains in terms of 5G target performance (e.g., user experience data rate and reliability) in urban and suburban areas. As another example, NTN and TN convergence networks can ensure connectivity not only in very dense areas (e.g., concert halls, sports stadiums, shopping centers, etc.) but also in fast-moving objects such as airplanes, bullet trains, vehicles and ships. there is. As another example, the NTN and TN integrated networks can simultaneously use data transmission services from the NTN network and the TN network through a multi-connection function. At this time, it is possible to obtain both the efficiency and economy of 5G wireless transmission service by selectively utilizing a better network according to the characteristics of traffic and the degree of loading of traffic.

Terminals located on plain land can use wireless data services by simultaneously connecting the NTN network and the TN network. In addition, the terminal can connect to one or more NTN platforms (e.g., two or more LEO/GEO satellites) at the same time to provide wireless data access service for poor environments or regions that are difficult to support in the TN network. Through this, the terminal can be utilized in association with various services. In particular, the integrated NTN network and TN network can improve the reliability of autonomous driving service and perform efficient network operation, and are not limited to the above-described embodiment.

Here, as an example, the V2X technology based on LTE mobile communication or the standard technology based on the IEEE 802.11p standard may have similar limitations on services that can be provided. The LTE V2X standard can be provided to meet the requirements defined on C-ITS (e.g., time delay of about 100ms, reliability of about 90%, and messages of tens to hundreds of bytes in size generated about 10 times per second, etc.). Therefore, a new V2X service may be required that requires low latency, high reliability, high volume data traffic, and improved positioning. At this time, as an example, standardization of 5G radio access technology (e.g., New Radio (NR)) is in progress based on the above. In addition, as an example, standardization of various numerologies, frame structures, and corresponding L2/L3 protocol structures is in progress so that requirements of new services can be more flexibly met than LTE. Based on the above, it is possible to support enhanced V2X services such as autonomous driving or remote driving by introducing sidelink wireless access technology based on 5G mobile communication technology, and for this purpose, the NTN network can be utilized.

As another example, the NTN network may be used to support IoT services for poor environments and areas not covered by terrestrial networks. For example, IoT equipment may frequently need to perform wireless communication with minimal power consumption in a poor channel environment (e.g., mountain, desert, or sea) according to the purpose of use. Cellular-based technologies proposed in the past may be mainly aimed at Mobile Broadband (MBB) services. Therefore, efficiency may be low to provide IoT service in terms of radio resource utilization and power control, and flexible operation may not be supported. Also, for example, in the case of non-cellular based existing IoT technology, there may be limitations in providing various IoT services due to limited mobility support and coverage. Considering the above points, the NTN network can be applied, and service can be improved through this.

In addition, as an example, if 5G mobile communication-based sidelink technology is applied through the NTN network, it is possible to provide users with wider coverage and mobility with a more efficient wireless communication method than current Bluetooth/Wi-Fi-based wearable equipment. . In addition, it can be differentiated from existing communication standards in applications (e.g. wearable multimedia service) that require high data transmission rates and mobility support using wearable devices.

As another example, it is possible to improve the public safety communication network and expand disaster communication coverage through the NTN network. For example, the high-reliability and low-latency technology of the 5G mobile communication system through the NTN network can provide public services such as disaster response. For example, mobile broadband service can be supported even in deserts or high mountains by using a mobile base station such as a drone supporting 5G mobile communication. That is, when the NTN network is applied to public services, disaster communication coverage can be expanded by covering various regions.

In the following, a method for improving a data transmission rate of a terminal and guaranteeing a successful reception probability of a data packet having a high quality of service (QoS) when using an NTN network based on the above description will be described. For example, in an NTN environment, the number of HARQ processes is limited, and communication may not be performed smoothly due to long propagation delay. Considering the above situation, HARQ feedback and UL retransmission for a UE performing uplink (UL) transmission in an NTN environment may be enabled/disabled. At this time, as an example, enable/disable for HARQ feedback and UL retransmission may be configured for each terminal. As another example, enable/disable for HARQ feedback and UL retransmission may be configured for each HARQ process. As another example, enable/disable for HARQ feedback and UL retransmission may be configured for each logical channel (LCH). That is, granularity for enable/disable for HARQ feedback and UL retransmission may be set differently and is not limited to a specific form.

As a specific example, in an NTN environment, a situation in which all HARQ processes are used due to a long propagation delay in a situation in which the number of HARQ processes is limited may occur, and accordingly, scheduling of the base station may be impossible. That is, stalling may occur. For example, when the round trip time (RTT) is greater than the total number of HARQ processes, the base station may be unable to perform scheduling in a situation in which all HARQ processes are used. Considering the above situation, whether to enable/disable HARQ feedback for downlink may be independently determined for each HARQ process. For example, whether downlink HARQ feedback is enabled/disabled may be semi-statically provided to the UE through RRC signaling. Also, as an example, in uplink, the base station may perform retransmission by performing scheduling for each HARQ process. Here, the base station may determine whether to enable/disable HARQ retransmission in order to prevent the aforementioned stalling phenomenon.

As a specific example, the base station may use a new data indicator (NDI) field of downlink control information (DCI) for retransmission. The base station may indicate whether to retransmit HARQ based on the toggle of the NDI value. However, since enabling/disabling of HARQ retransmission in the NTN environment can be set for each HARQ process, even if the terminal receives DCI in which the NDI value is toggled, whether new transmission is indicated or whether HARQ retransmission is disabled and new transmission is performed may not be clearly perceived. Accordingly, the base station may semi-statically instruct the terminal whether to enable/disable uplink HARQ retransmission through RRC signaling. For example, the terminal may recognize whether HARQ retransmission is enabled/disabled for each HARQ process through RRC signaling. At this time, when the UE is instructed whether to enable/disable HARQ retransmission for each HARQ process through RRC signaling as described above, the timer operation and definition may be clear for each HARQ process, but flexible scheduling may not be performed in the network. . That is, the terminal may use a retransmission method configured for each HARQ process through RRC signaling, and whether to enable/disable HARQ retransmission may be changed only by RRC signaling.

As another example, enabling/disabling HARQ retransmission may be dynamically indicated through DCI. More specifically, the terminal may semi-statically configure the HARQ process through RRC signaling, and may be instructed to enable/disable HARQ retransmission through the received DCI. At this time, as an example, enable/disable of HARQ retransmission may be indicated based on the DCI format.

As another example, the terminal may not be instructed whether to enable/disable HARQ retransmission. Here, when the terminal receives a UL / DL grant / assignment including a toggled NDI value indicating new transmission, the terminal transmits the previous TB (transport block) in the corresponding HARQ process. can be recognized as Here, determination of whether the transmitted TB has been successfully decoded based on the previous HARQ process may not be performed. That is, the terminal can receive a new grant/assignment in which NDI is toggled before HARQ-RTT, and through this, the network can perform flexible scheduling for all HARQ processes. That is, as described above, whether to enable/disable HARQ retransmission may be indicated in different ways, and may not be limited to a specific form.

However, in the following, when the terminal performs uplink transmission to the base station, HARQ retransmission operation is performed based on the case where HARQ retransmission enable/disable is set to semi-static based on RRC signaling. It describes how to do it, but may not be limited thereto.

For example, when the terminal performs uplink transmission to the base station, the terminal may perform uplink transmission based on a configured grant (CG). In this case, the CG may be an uplink resource that is periodically configured in advance in the UE. That is, the UE can perform uplink transmission through a resource already configured based on CG without a UL grant. Accordingly, the terminal can perform uplink transmission in a grant-free manner, thereby reducing delay. Here, uplink transmission performed based on CG may be performed based on either CG type 1 or CG type 2. For example, CG type 1 may be a type in which whether or not to activate a periodically configured uplink resource in advance is indicated based on RRC signaling. That is, L1 signaling may not be required in GC type 1. On the other hand, in CG type 2, uplink resources that are periodically configured in advance are configured through RRC signaling, and activation of the configured uplink resources may be indicated through L1 signaling (eg DCI). Here, as an example, a configured grant timer (CGT) may be set to prevent reuse of the HARQ process for CG Type 1/CG Type 2.

In more detail, FIG. 12 is a diagram showing a HARQ process configuration to which the present disclosure is applicable. Referring to FIG. 12, HARQ processes may be distinguished based on HARQ process IDs. Here, a plurality of HARQ processes may be used in the terminal, and an HARQ process for the GG may be configured among the plurality of HARQ processes. For example, the terminal may derive the HARQ process ID to be used for each CG resource based on Equation 3 or Equation 4 below. The terminal may obtain CG configuration information (e.g. ConfiguredGrantConfig) through RRC signaling, and based on this, an HARQ process ID may be derived through Equation 3 or Equation 4 below.

As a specific example, when the HARQ process offset (harq-ProcID-Offset2) is configured in the CG configuration information, the HARQ process ID is greater than the HARQ process offset (harq-ProcID-Offset2) based on Equation 2 below, the HARQ process offset and It may be set smaller than the sum of the number of HARQ processes. In FIG. 12, the number of HARQ processes of the HARQ entity may be set to 16. However, this is only one example, and the number of HARQ processes may be set differently. At this time, if the HARQ process offset (harq-ProcID-Offset2) is 13 and the number of HARQ processes (nrofHARQ-Processes) to be used in the UL CG is 3, the HARQ process for the UL CG is the HARQ process corresponding to the HARQ process ID #14 1210, the HARQ process 1220 corresponding to the HARQ process ID #15 and the HARQ process 1230 corresponding to the HARQ process ID #16. At this time, as an example, the HARQ process 1220 corresponding to HARQ process ID #15 and the HARQ process 1230 corresponding to HARQ process ID #16 may be HARQ processes in which HARQ retransmission is enabled, which will be described later.

[Equation 3]

HARQ Process ID = [floor(CURRENT_symbol/periodicity)] modulo nrofHARQ?Processes

[Equation 4]

HARQ Process ID = [floor(CURRENT_symbol/periodicity)]modulo nrofHARQ?Processes+ harq-ProcID?Offset2

For example, when a TB to be transmitted to the UE occurs, the UE may perform PUSCH transmission through CG resources. Here, the CGT may operate for HARQ Process num#X of CG resources. At this time, the terminal may ignore the grant for the corresponding HARQ Process#X in the CG in which the CGT is operating.

In more detail, FIG. 13 is a diagram illustrating a method of performing CG retransmission based on a CG HARQ process and CGT to which the present disclosure is applicable. As an example, referring to FIG. 13 , the terminal may be configured with a periodicity and the number of HARQ processes (nrofHARQ-Process) based on CG information (e.g. ConfiguredGrantConfig) received through RRC signaling. For example, CG information received through RRC signaling may be as shown in Table 5 below, but may not be limited thereto.

As an example, in FIG. 13, the terminal may be configured for UL CG in 3 out of 16 HARQ processes in a period of 56 symbols, and CG resources may be configured in every 4 slots of 56 symbols. At this time, the HARQ process ID (or number, HARQ process ID (PID)) used in each slot may be determined sequentially based on Equation 3 or Equation 4.

At this time, as an example, CGT operates in the determined HARQ PID without overlapping with Random access response / MsgA payload / PUSCH duration (PUSCH duration (Temporary C-RNTI)) resources in CG resources. If not, the MAC layer of the UE may perform new transmission through the CG resource to the HARQ entity. On the other hand, when CGT operates in a resource having the same HARQ process ID (HARQ PID#X), the UE may wait for a data retransmission grant for the same HARQ process ID (HARQ PID#X). That is, the CGT may be a time for waiting for a retransmission grant, and may be a time for determining whether data transmitted from the terminal to the base station is successfully decoded. For example, in FIG. 13, the UE may transmit data to the base station through the PUSCH in the first CG resource 1310 for which HARQ PID#0 is determined. After the terminal transmits data to the base station through HARQ PID#0, the terminal may operate CGT for HARQ PID#0 of the first CG resource 1310. Through this, the UE can prevent reuse of CG resources using the same HARQ PID. If the terminal does not receive the retransmission-related grant while the CGT is operating, the terminal may determine that the base station has successfully decoded the data. Thereafter, the UE may transmit a new TB in the CG resource 1320 after HARQ PID#0 is determined.

On the other hand, if the base station fails to receive the PUSCH, the base station may transmit the PDCCH scrambled with CS-RNTI before the CGT expires and set the NDI to a first value (e.g. 1) to the terminal. At this time, the terminal may recognize that retransmission is necessary through the DCI of the PDCCH. That is, the base station may instruct retransmission in relation to HARQ PID#0. Accordingly, when the UE receives the PDCCH of CS-RNTI, NDI=1, and PID#0 before the CGT expires, the UE may perform UL retransmission and restart the CGT. Accordingly, since the CGT is operating in the next CG resource 1320 for HARQ PID#0, the terminal may not be able to perform new TB transmission in the next CG resource 1320.

[Table 5]

As another example, FIG. 14 is a diagram illustrating a method in which a terminal to which the present disclosure is applicable performs new transmission based on a PDCCH scrambled with a C-RNTI. For example, referring to FIG. 14, the terminal may transmit data to the base station in the first CG resource 1410 in which HARQ PID#0 is determined. After transmitting data to the base station through HARQ PID#0, the terminal may operate CGT for HARQ PID#0 of the first CG resource 1410. Through this, the UE can prevent reuse of the same HARQ PID.

For example, before the CGT expires, the MAC entity of the UE may receive the PDCCH scrambled with the C-RNTI. When the UE receives a PDCCH scrambled with C-RNTI based on a dynamic grant (DG), the UE may determine that new transmission has been instructed for the corresponding HARQ PID. That is, the UE may determine that a new transmission is instructed based on the DG without considering whether the previous grant is used in the CG and whether retransmission is scheduled in the CS-RNTI for the corresponding HARQ PID. At this time, the UE may transmit a new TB in the corresponding resource based on the corresponding HARQ PID. Here, if the HARQ PID is related to the CG, it is possible to prevent new transmission in the next CG resource by operating the CGT based on the HARQ PID of the corresponding resource.

As a specific example, in FIG. 14 , the UE may perform TB transmission based on HARQ PID#0 in the first CG resource 1410 and operate CGT. At this time, when the terminal is scrambled with C-RNTI based on DG and receives a PDDCH associated with HARQ PID#0, the terminal performs new TB transmission based on HARQ PID#0, and in HARQ PID#0 of the resource Based on this, CGT can be restarted. Accordingly, CGT for HARQ PID#0 may be in operation in the next CG resource 1420, and thus new data transmission may not be performed.

As described above, whether the CGT of a specific HARQ PID#X has expired may be a timer for checking whether the base station has successfully received the TB transmitted by the terminal. In this case, the CGT may be determined based on a timer value related to retransmission of the UE. For example, after transmitting data to the base station, the terminal receives the retransmission PDCCH while the UL DRX HARQ RTT timer (drx-HARQ-RTT-TimerUL) expires and the UL DRX retransmission timer (drx-RetransmissionTimerUL) is running. It can be recognized that the reception is successful.

Considering the above, CGT may be set to a value including a UL DRX HARQ RTT timer (drx-HARQ-RTT-TimerUL) and a UL DRX retransmission timer (drx-RetransmissionTimerUL). That is, the base station can set CGT values from 1 to 64 as shown in Table 5 in order to variably set CGT (periodicity×configuredGrantTimer) in consideration of RTT.

More specifically, when the terminal performs UL transmission, the terminal may receive a PDCCH indicating retransmission from the base station after the UL DRX HARQ RTT timer (drx-HARQ-RTT-TimerUL) in consideration of RTT. Here, when the UL DRX HARQ RTT timer expires, the UL DRX retransmission timer (drx-RetransmissionTimerUL) starts, and the UE receives a PDCCH indicating retransmission before the UL DRX retransmission timer (drx-RetransmissionTimerUL) expires to perform retransmission. can On the other hand, if the terminal does not receive the PDCCH indicating retransmission until the UL DRX retransmission timer (drx-RetransmissionTimerUL) expires, the terminal may determine that the base station has successfully received data. That is, in consideration of the above-described operation, the CGT may be set to a value including the UL DRX HARQ RTT timer (drx-HARQ-RTT-TimerUL) and the UL DRX retransmission timer (drx-RetransmissionTimerUL), but is not limited thereto. can

As described above, CGT may operate based on the HARQ process. In addition, considering the NTN environment, whether to enable/disable HARQ retransmission for the HARQ process may be semi-statically determined based on RRC signaling. Here, as an example, whether to enable/disable HARQ retransmission may be explicitly indicated through RRC signaling based on CGT. As another example, whether to enable/disable HARQ retransmission may be implicitly indicated based on the CGT, which will be described below.

For example, whether to enable/disable HARQ retransmission may be explicitly indicated through RRC signaling.

For example, in relation to a dynamic grant (DG) instructing uplink transmission to a UE, an HARQ retransmission method may be configured for each HARQ process, and may be determined according to quality of service (QoS) characteristics of a logical channel (LCH). can In this case, the HARQ retransmission method may be determined based on logical channel priority (LCP) in which the LCH is mapped to the HARQ process, but may not be limited thereto.

Here, HARQ retransmission for the CG resource may be performed based on an HARQ process, but may not be limited thereto. For example, when HARQ retransmission of CG resources is performed based on the HARQ process, and whether to enable/disable HARQ retransmission is explicitly indicated based on RRC signaling, even in HARQ retransmission of CG resources, LCP is the same as DG. An LCH may be selected based on a procedure and mapped to a HARQ process or HARQ retransmission method. That is, LCH selection may be performed based on the HARQ PID of the determined CG resource or the HARQ retransmission method of the HARQ PID allocated to the DG, but may not be limited thereto.

Here, when whether to enable/disable HARQ retransmission is explicitly indicated through RRC signaling, a CG configuration may be set in the UE through RRC signaling based on Table 5 above. The UE may derive an HARQ process ID to be used for each PUSCH duration based on the CG configuration information. As another example, the terminal may perform the HARQ process operation based on the HARQ retransmission method according to RRC signaling or the operation of the DRX HARQ RTT timer (drx-HARQ-RTT-TimerUL) and the DRX retransmission timer (drx-RetransmissionTimerUL), It is not limited to the above-described embodiment. As an example, FIG. 15 is a diagram illustrating a method of instructing HARQ retransmission enable/disable based on a CGT to which the present disclosure is applicable.

Referring to FIG. 15, a plurality of UL HARQ processes may be configured in a terminal. In this case, whether to enable/disable HARQ retransmission for each HARQ process configured in the terminal may be indicated through RRC signaling. For example, in FIG. 15, HARQ retransmission is disabled in the CG resource 1510 whose HARQ process ID is PID#0, and HARQ retransmission is enabled in the CG resources 1520 and 1530 with PID#1 and PID#2. there is.

In addition, as an example, based on Table 5 in FIG. 15, in a situation where there are 16 UL HARQ processes, the number of HARQ processes (nrofHARQ-Processes) is determined to be 3, and the HARQ process offset (harq-procID-Offset2) is composed of 13 However, this is only one example and is not limited to the above-described embodiment. For example, in an NTN environment, the number of HARQ processes may be increased to 16 or more in consideration of delay, and may not be limited to a specific embodiment. That is, since the number of HARQ processes may increase in NTN, the situation in which the total number of HARQ processes is 16 is not limited.

Here, referring to FIG. 15, the base station may instruct HARQ retransmission disable for HARQ PID#0 and HARQ retransmission enable for HARQ PID#1 and HARQ PID#2 through an RRC message. At this time, since retransmission is disabled for HARQ PID #0, retransmission may not be performed for HARQ PID #0. That is, the base station may continuously perform scheduling in relation to HARQ PID #0. In addition, the UE may not operate the DRX HARQ RTT timer (drx-HARQ-RTT-TimerUL) because there is no grant retransmitted in HARQ PID#0 in which HARQ retransmission is disabled. Also, the terminal may not operate the CGT. That is, the terminal may perform new TB transmission at any time using CG resources associated with HARQ PID#X without operating CGT after transmitting TB through HARQ PID#X in which HARQ retransmission is disabled. For example, when the UE receives a PDCCH UL grant that is scrambled with C-RNTI based on DG and includes HARQ PID#0 associated with the CG, the UE transmits data and indicates the HARQ PID#0 CG period A new transmission can also be performed.

Here, FIG. 16 is a diagram illustrating a HARQ retransmission enable/disable based CG configuration and procedure between a terminal and a base station applicable to the present disclosure. Referring to FIG. 16 , a terminal 1610 may receive information about enabling/disabling HARQ retransmission for a UL HARQ process through an RRC message (system information, reconfiguration). For example, whether to enable/disable HARQ retransmission may be configured for each HARQ process, as described above. In addition, whether to enable/disable HARQ retransmission may be commonly configured in the network, may be configured UE-specifically, and may not be limited to a specific form. After that, the base station 1620 may provide CG configuration information to the terminal to configure CG resources, which may be as shown in Table 5 above. At this time, the UE may operate CGT in the selected PUSCH duration of the HARQ process in which HARQ retransmission is enabled, and may not operate CGT in the HARQ process in which HARQ retransmission is disabled.

As another example, the base station may not set whether to enable/disable HARQ retransmission for each HARQ process through RRC signaling. That is, the base station may not explicitly indicate whether to enable/disable HARQ retransmission. In this case, the base station may indicate whether to enable/disable HARQ retransmission based on the DRX HARQ RTT timer (drx-HARQ-RTT-TimerUL) and the DRX retransmission timer (drx-RetransmissionTimerUL). That is, the base station may implicitly instruct the terminal whether to enable/disable HARQ retransmission.

As an example, FIG. 17 is a diagram illustrating a method of implicitly indicating whether to enable/disable HARQ retransmission to which the present disclosure is applicable. As an example, the UE may receive DRX HARQ RTT timer (drx-HARQ-RTT-TimerUL) and DRX retransmission timer (drx-RetransmissionTimerUL) values from the base station. Here, the UE may determine whether to enable/disable HARQ retransmission based on the values of the DRX HARQ RTT timer (drx-HARQ-RTT-TimerUL) and the DRX retransmission timer (drx-RetransmissionTimerUL). More specifically, when both the DRX HARQ RTT timer (drx-HARQ-RTT-TimerUL) and the DRX retransmission timer (drx-RetransmissionTimerUL) are set to 0, the UE may consider that HARQ retransmission is disabled. That is, since the DRX HARQ RTT timer (drx-HARQ-RTT-TimerUL) is 0, the UE does not consider RTT, and since the DRX retransmission timer (drx-RetransmissionTimerUL) is also 0, grant reception for retransmission may not be considered. Accordingly, the UE may not expect reception of a UL grant related to retransmission after performing data transmission from the CG resource to the base station. At this time, the terminal may not operate the CGT.

As a specific example, in FIG. 17, the terminal may configure a CG based on CG configuration information. For example, CG#1 (1710), CG#2 (1720), CG#3 (1730), and CG#4 (1740) mean resources for each set period (Periodicity), and the HARQ PID to be used in each resource is The terminal may determine based on Equation 3 or Equation 4 above. Here, HARQ PID#1 may be derived for CG#1 (1710) and CG#3 (1730), and PID#2 may be derived for CG#2 (1720) and CG#4 (1740). It is only an example and is not limited to the above-described embodiment.

At this time, the terminal can set the number of HARQ processes to be used in the CG (nrofHARQ-processes) and the HARQ process offset (harq-ProcID-Offset2) based on the CG configuration information of Table 5 above. For example, in FIG. 17, the number of HARQ processes to be used in CG is 2, and the HARQ process offset (harq-ProcID-Offset2) may be set to 0. At this time, in the HARQ PID#1 determined by CG#1 1710 and CG#3 1730, both the DRX HARQ RTT timer (drx-HARQ-RTT-TimerUL) and the DRX retransmission timer (drx-RetransmissionTimerUL) are set to 0. can

At this time, the UE may recognize that HARQ retransmission is disabled through the DRX HARQ RTT timer (drx-HARQ-RTT-TimerUL) and the DRX retransmission timer (drx-RetransmissionTimerUL). That is, the terminal may not expect to receive a retransmission grant for the TB transmitted through CG#1 1710 and CG#3 1730. Therefore, the terminal and the base station can perform continuous scheduling using HARQ PID#1. Also, CGT may not operate in CG resources related to HARQ PID#1. For example, CGT does not operate after transmitting TB#A in CG#1 1710, and CGT does not operate in CG#3 1730, so a new TB#C can be transmitted.

On the other hand, if both the DRX HARQ RTT timer (drx-HARQ-RTT-TimerUL) and the DRX retransmission timer (drx-RetransmissionTimerUL) are not set to 0, the UE may consider that HARQ retransmission is enabled. That is, the terminal can expect to receive a retransmission UL grant from the base station after data transmission in the CG resource. At this time, the terminal operates the CGT and may not transmit a new TB in the next CG resource based on the CGT when receiving the retransmission grant having the HARQ PID.

For example, in FIG. 17 , in HARQ PID#2 determined by CG#2 1720 and CG#4 1740, the DRX HARQ RTT timer (drx-HARQ-RTT-TimerUL) and the DRX retransmission timer (drx-RetransmissionTimerUL) are 0 may not be set to . Therefore, it may be implicitly indicated that HARQ retransmission is enabled for HARQ PID#2. That is, the terminal can expect to receive a retransmission grant for the TB transmitted through CG#2 1720 and CG#4 1740. At this time, the terminal and the base station may also operate CGT based on HARQ retransmission enable using HARQ PID#2. As a specific example, the terminal may operate CGT after transmitting TB#B in CG#2 1720. At this time, since the CGT operates in CG#4 1740, transmission of a new TB may not be performed.

As another example, FIG. 18 is a diagram illustrating a method of implicitly indicating HARQ retransmission enable/disable to which the present disclosure is applicable.

For example, both the DRX HARQ RTT timer (drx-HARQ-RTT-TimerUL) and the DRX retransmission timer (drx-RetransmissionTimerUL) are not set to 0, and only the DRX HARQ RTT timer (drx-HARQ-RTT-TimerUL) is set to 0. It can be. Since the DRX HARQ RTT timer (drx-HARQ-RTT-TimerUL) is 0, the UE can immediately start the DRX retransmission timer (drx-RetransmissionTimerUL) after data transmission. At this time, the terminal can expect blind retransmission while the DRX retransmission timer (drx-RetransmissionTimerUL) is operating.

As a specific example, referring to FIG. 18 , the terminal may configure a CG based on CG configuration information. For example, CG#1 (1810), CG#2 (1820), CG#3 (1830), and CG#4 (1840) mean resources for each set period (Periodicity), and the HARQ PID to be used in each resource is The terminal may determine based on Equation 3 or Equation 4 above. Here, HARQ PID#1 may be derived for CG#1 (1810) and CG#3 (1830), and PID#2 may be derived for CG#2 (1820) and CG#4 (1840). It is only an example and is not limited to the above-described embodiment. At this time, the terminal can set the number of HARQ processes to be used in the CG (nrofHARQ-processes) and the HARQ process offset (harq-ProcID-Offset2) based on the CG configuration information of Table 5 above. For example, in FIG. 18, the number of HARQ processes to be used in CG is 2, and the HARQ process offset (harq-ProcID-Offset2) may be set to 0.

At this time, in the HARQ PID#1 determined by CG#1 1810 and CG#3 1830, the DRX HARQ RTT timer (drx-HARQ-RTT-TimerUL) is set to 0 and the DRX retransmission timer (drx-RetransmissionTimerUL) is set to 0. Can be set to a non-zero value. Based on the foregoing, HARQ blind retransmission may be implied for HARQ PID#1.

That is, the UE does not expect to receive a retransmission grant for the TBs transmitted through CG#1 1810 and CG#3 1830, but may be monitoring blind retransmission. As a specific example, the terminal receives the PDCCH scrambled with C-RNTI based on HARQ PID#1 while the DRX retransmission timer (drx-RetransmissionTimerUL) is operating, and performs blind retransmission through HARQ PID#1 based on the NDI value. can be done Therefore, the terminal and the base station can use HARQ PID#1 for continuous scheduling and can use a blind retransmission grant. At this time, as an example, the terminal may operate a CGT timer to prevent the use of the same HARQ PID. As another example, the UE may perform an operation as much as the DRX retransmission timer (drx-RetransmissionTimerUL) for HARQ PID # 1 or operate a new timer by a specific value in consideration of the DRX retransmission timer (drx-RetransmissionTimerUL). can

As an example, FIG. 19 is a diagram illustrating a new timer to which the present disclosure can be applied. In this case, the name of the new timer may not be limited to a specific name, and may be a timer based on the following purpose. In FIG. 19 , after CG#1 1910 transmits TB#A for HARQ PID#1, a DRX retransmission timer (drx-RetransmissionTimerUL) for receiving a blind retransmission grant may operate. Here, the terminal may operate a new timer (NewTimer) that plays the same role as the CGT for HARQ PID#1 in order not to perform new transmission in CG#3 1920 where the same HARQ PID#1 is determined. That is, the terminal may not perform new transmission in the resource of CG#3 1930 for HARQ PID#1 in which the new timer (NewTimer) operates.

At this time, as an example, the terminal may receive the DCI scrambled with the C-RNTI and determine that it is a new transmission regardless of the NDI of the previous grant (Configured Grant or Retransmission Grant (CS-RNTI)) in which the corresponding HARQ process was used. When the terminal receives DCI scrambled with C-RNTI, it can determine whether to perform new transmission or retransmission according to the NDI of the previous grant (Configured Grant or Retransmission Grant (CS-RNTI)) in which the corresponding HARQ process was used. As a specific example, when the UE receives the PDCCH (C-RNTI) for HARQ Process ID#X while the DRX retransmission timer (drx-RetransmissionTimerUL) for the UE or the new timer is running, the UE receives the HARQ Process ID#X It is possible to determine whether to perform new transmission or HARQ blind retransmission by comparing the previously transmitted NDI value with , and is not limited to the above-described embodiment.

20 is a flowchart illustrating a method of explicitly indicating whether to enable/disable HARQ retransmission to which the present disclosure is applicable. Referring to FIG. 20 , a terminal may be a terminal performing communication in an NTN environment. At this time, the terminal may receive information indicating whether to enable/disable HARQ retransmission from the base station through RRC signaling (S2010). In addition, the terminal may receive CG configuration information from the base station, and the received information (S2020) At this time, the CG configuration information may be the information of Table 5 above, and based on the CG configuration information, the CG resources may be configured in the PUSCH duration. At this time, the terminal may check whether HARQ retransmission is enabled or disabled for each HARQ process based on the instructed HARQ retransmission enable/disable information. At this time, when the terminal transmits data in the CG resource based on the HARQ process ID for which HARQ retransmission is enabled (S2030), the terminal operates the CGT timer and operates the corresponding HARQ process ID based on the HARQ process ID until the CGT timer expires. New data transmission of the process may not be performed (S2040). That is, HARQ retransmission for the corresponding HARQ process is enabled, and the terminal may operate the CGT at the time for receiving the retransmission grant. On the other hand, at this time, when the terminal transmits data in the CG resource based on the HARQ process ID in which HARQ retransmission is disabled (S2030), the terminal does not operate the CGT timer, and based on the HARQ process ID, New data transmission can be performed (S2050). That is, the terminal and the base station can freely perform scheduling for the corresponding HARQ process, and through this, communication can be performed considering a large delay in the NTN environment.

21 is a flowchart illustrating a method of implicitly indicating whether to enable/disable HARQ retransmission to which the present disclosure is applicable.

Referring to FIG. 21 , a terminal may be a terminal performing communication in an NTN environment. At this time, the terminal may configure CG resources based on the CG configuration information and transmit data to the base station, as shown in FIG. 20 (S2110). At this time, whether to enable/disable HARQ retransmission is implicitly indicated to the terminal. can For example, the terminal may recognize whether to enable/disable HARQ retransmission based on the values of the HARQ RTT timer and the HARQ retransmission timer. For example, when the HARQ RTT timer is set to a non-zero value (S2120) and the HARQ retransmission timer is also set to a non-zero value (S2130), the UE recognizes that HARQ retransmission is enabled and operates the CGT timer to correspond to the The HARQ process may operate in consideration of the HARQ retransmission operation. (S2140) On the other hand, if the HARQ RTT timer is set to 0 (S2120) and the HARQ retransmission timer is also set to 0 (S2150), the UE disables HARQ retransmission (S2160) Also, for example, when the HARQ RTT timer is set to 0 (S2120), but the HARQ retransmission timer is set to a value other than 0 (S2170), the terminal may operate a new timer or CGT. (S2170) At this time, the terminal may expect HARQ blind retransmission, which may be the same as the above-described FIG. 19.

22 is a diagram showing a device configuration to which the present disclosure can be applied.

Referring to FIG. 22 , the first device 2200 and the second device 2250 may perform mutual communication. In this case, for example, the first device 2200 may be a base station device, and the second device 2250 may be a terminal device. As another example, both the first device 2200 and the second device 2250 may be terminal devices. That is, the first device 2200 and the second device 2250 may be devices that perform mutual communication based on sidelink communication.

As an example, a case where the first device 2200 is a base station device and the second device 2250 is a terminal device may be considered. In this case, the base station device 2200 may include a processor 2220, an antenna unit 2212, a transceiver 2214, and a memory 2216. The processor 2220 performs baseband-related signal processing and may include an upper layer processing unit 2230 and a physical layer processing unit 2240. The upper layer processing unit 2230 may process operations of a medium access control (MAC) layer, a radio resource control (RRC) layer, or higher layers. The physical layer processing unit 2240 may process physical (PHY) layer operations (eg, uplink received signal processing and downlink transmission signal processing). The processor 2220 may control overall operations of the base station apparatus 2200 in addition to performing baseband-related signal processing. The antenna unit 2212 may include one or more physical antennas, and may support multiple input multiple output (MIMO) transmission and reception when including a plurality of antennas. In addition, beamforming may be supported. The memory 2216 may store information processed by the processor 2220, software related to the operation of the base station device 2200, an operating system, an application, and the like, and may include components such as a buffer. The processor 2220 of the base station apparatus 2200 may be configured to implement the operation of the base station in the embodiments described in the present invention.

The terminal device 2250 may include a processor 2270, an antenna unit 2262, a transceiver 2264, and a memory 2266. For example, in the present invention, the terminal device 2250 may communicate with the base station device 2200. As another example, in the present invention, the terminal device 2250 may perform sidelink communication with another terminal device. That is, the terminal device 2250 of the present invention refers to a device capable of communicating with at least one of the base station device 2200 and other terminal devices, and is not limited to communication with a specific device. The processor 2270 performs baseband-related signal processing and may include an upper layer processing unit 2280 and a physical layer processing unit 2290. The upper layer processing unit 2280 may process operations of a MAC layer, an RRC layer, or higher layers. The physical layer processing unit 2290 may process PHY layer operations (eg, downlink reception signal processing, uplink transmission signal processing, and sidelink signal processing). In addition to performing baseband-related signal processing, the processor 2270 may also control overall operations of the terminal device 2250 . The antenna unit 2262 may include one or more physical antennas, and may support MIMO transmission and reception when including a plurality of antennas. In addition, beamforming may be supported. The memory 2266 may store information processed by the processor 2270, software related to the operation of the terminal device 2250, an operating system, an application, and the like, and may include components such as a buffer. The terminal device 2250 according to an example of the present invention may be associated with a vehicle. For example, the terminal device 2250 may be integrated into a vehicle, located in a vehicle, or located on a vehicle. Also, the terminal device 2250 according to the present invention may be a vehicle itself. In addition, the terminal device 2250 according to the present invention may be at least one of a wearable terminal, an AV/VR terminal, an IoT terminal, a robot terminal, and a public safety terminal. The terminal device 2250 to which the present invention can be applied can be any of various types in which interactive services using sidelinks are supported for services such as Internet access, service execution, navigation, real-time information, autonomous driving, and safety and risk diagnosis. Communication devices may also be included. In addition, any type of communication device that performs a relay operation as an AR/VR device capable of sidelink operation or a sensor may be included.

Here, vehicles to which the present invention is applied may include autonomous vehicles, semi-autonomous vehicles, and non-autonomous vehicles. Meanwhile, the terminal device 2250 according to an example of the present invention is described as being associated with a vehicle, but one or more of the UEs may not be associated with a vehicle. This is an example and should not be construed to limit the application of the present invention according to the described example. In addition, the terminal device 2250 according to an example of the present invention may also include various types of communication devices capable of performing cooperation supporting an interactive service using sidelink. That is, it may be used not only when the terminal device 2250 directly supports an interactive service using a sidelink, but also as a cooperative device for supporting an interactive service using a sidelink.

In addition, various embodiments of the present disclosure may be implemented by hardware, firmware, software, or a combination thereof. For hardware implementation, one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), It may be implemented by a processor (general processor), controller, microcontroller, microprocessor, or the like.

The scope of the present disclosure is software or machine-executable instructions (eg, operating systems, applications, firmware, programs, etc.) that cause operations in accordance with the methods of various embodiments to be executed on a device or computer, and such software or It includes a non-transitory computer-readable medium in which instructions and the like are stored and executable on a device or computer.

Various embodiments of the present disclosure are intended to explain representative aspects of the present disclosure, rather than listing all possible combinations, and matters described in various embodiments may be applied independently or in combination of two or more.

The above can be applied to various systems.

Claims (12)

In a method for a terminal to perform hybrid automatic repeat request (HARQ) retransmission based on a non-terrestrial network (NTN) in a wireless communication system, Receiving a radio resource control (RRC) message indicating whether to enable or disable HARQ retransmission from a base station; Receiving configured grant (CG) configuration information configured from the base station; and Performing data transmission in the CG resource indicated through the CG configuration information in consideration of whether the HARQ retransmission is enabled or disabled; Including, When the HARQ process of the CG resource is HARQ retransmission enabled, a configured grant timer (CGT) is operated after the data is transmitted in the CG resource, and a new new one is based on the HARQ process until the CGT expires. no data transfer is performed; If the HARQ process of the CG resource is HARQ retransmission disabled, the CGT is not operated after the data is transmitted in the CG resource, and new data transmission is performed based on the HARQ process. How to perform HARQ retransmission. According to claim 1, Whether to enable or disable the HARQ retransmission is determined for each HARQ process. According to claim 1, If the HARQ process of the CG resource is the HARQ retransmission disabled, when receiving a physical downlink control channel (PDCCH) uplink grant associated with the CG resource after the data is transmitted in the CG resource Performing the new data transmission through the CG resource based on the uplink grant, HARQ retransmission method. According to claim 1, Wherein whether the HARQ retransmission is enabled or disabled is UE-specifically set. In a terminal performing hybrid automatic repeat request (HARQ) retransmission based on non-terrestrial networks (NTN) in a wireless communication system, transceiver; a processor connected to the transceiver; the processor, Receiving a radio resource control (RRC) message indicating whether to enable or disable HARQ retransmission from a base station through the transceiver, Receiving configured grant (CG) configuration information configured from the base station through the transceiver, and Performing data transmission in the CG resource indicated through the CG configuration information in consideration of whether the HARQ retransmission is enabled or disabled, When the HARQ process of the CG resource is HARQ retransmission enabled, a configured grant timer (CGT) is operated after the data is transmitted in the CG resource, and a new new one is based on the HARQ process until the CGT expires. no data transfer is performed; If the HARQ process of the CG resource is HARQ retransmission disabled, the CGT is not operated after the data is transmitted in the CG resource, and new data transmission is performed based on the HARQ process, performing HARQ retransmission Terminal. According to claim 5, Whether to enable or disable the HARQ retransmission is determined for each HARQ process. According to claim 5, If the HARQ process of the CG resource is the HARQ retransmission disabled, when receiving a physical downlink control channel (PDCCH) uplink grant associated with the CG resource after the data is transmitted in the CG resource A terminal performing HARQ retransmission, which performs the new data transmission through the CG resource based on the uplink grant. According to claim 5, Whether the HARQ retransmission is enabled or disabled is set to be UE-specific, a terminal that performs HARQ retransmission. In a method for a terminal to perform hybrid automatic repeat request (HARQ) retransmission based on a non-terrestrial network (NTN) in a wireless communication system, Receiving a radio resource control (RRC) message indicating whether to enable or disable HARQ retransmission from a base station; Receiving configured grant (CG) configuration information configured from the base station; and Performing data transmission in the CG resource indicated through the CG configuration information in consideration of whether the HARQ retransmission is enabled or disabled; Including, When the HARQ process of the CG resource is HARQ retransmission enabled, a configured grant timer (CGT) is operated after the data is transmitted in the CG resource, and the HARQ after the data is transmitted based on the CG resource. When a dynamic grant associated with a process is received from the base station, new data transmission is performed in a resource indicated by the dynamic grant based on the HARQ process. According to claim 9, If the new data transmission is performed based on the HARQ process in the resource indicated by the dynamic grant, the CGT restarts after the new data is transmitted. In a terminal performing hybrid automatic repeat request (HARQ) retransmission based on non-terrestrial networks (NTN) in a wireless communication system, transceiver; a processor connected to the transceiver; the processor, Receiving a radio resource control (RRC) message indicating whether to enable or disable HARQ retransmission from a base station through the transceiver, Receiving configured grant (CG) configuration information configured from the base station through the transceiver, and Performing data transmission in the CG resource indicated through the CG configuration information in consideration of whether the HARQ retransmission is enabled or disabled, When the HARQ process of the CG resource is HARQ retransmission enabled, a configured grant timer (CGT) is operated after the data is transmitted in the CG resource, and the HARQ after the data is transmitted based on the CG resource. Upon receiving a dynamic grant associated with a process from the base station, the UE performs new data transmission in a resource indicated by the dynamic grant based on the HARQ process. According to claim 11, When the new data transmission is performed based on the HARQ process in the resource indicated by the dynamic grant, the CGT restarts after the new data is transmitted.

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