KR20230015198A - Method and apparatus for performing data decoding in wireless communication system - Google Patents

Abstract

The present invention may provide a method for a terminal to perform data decoding based on NTN in a wireless communication system in a wireless communication system. At this time, the method for performing data decoding by the terminal includes identifying an SPS PDSCH set (Q) including a plurality of SPS PDSCHs for one serving cell in one slot, a plurality of SPS PDSCHs in the SPS PDSCH set (Q) It may include checking information on whether HARQ-ACK feedback is set for each and selecting at least one SPS PDSCH to perform decoding from among a plurality of SPS PDSCHs.

Description

Method and apparatus for performing data decoding of a terminal in a wireless communication system

The present invention relates to a method and apparatus for performing data decoding of a terminal in a wireless communication system.

The present invention relates to a method of decoding data when a terminal receives data based on a non-terrestrial network (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 may provide a method and apparatus for decoding data of a terminal in a wireless communication system.

The present invention can provide a method and apparatus for a terminal to decode data in consideration of the NTN environment.

The present invention provides a method for selecting an SPS PDSCH to be decoded by a terminal when a plurality of semi-persistent scheduling (SPS) physical downlink shared channels (PDSCHs) are set in one slot in consideration of the NTN environment. can provide

The present invention may provide a method for determining whether to provide hybrid automatic repeat request (HARQ) feedback for each PDSCH in an NTN environment.

The present invention may provide a method of performing data decoding based on whether each PDSCH has HARQ feedback in an NTN environment.

The present invention can provide a method for a terminal to perform data decoding based on NTN in a wireless communication system. At this time, the method for performing data decoding by the terminal includes the step of identifying an SPS PDSCH set (Q) including a plurality of SPS PDSCHs for one serving cell in one slot, a plurality of SPS PDSCHs in the SPS PDSCH set (Q) It may include checking information on whether HARQ-ACK feedback is set for each and selecting at least one SPS PDSCH to perform decoding from among a plurality of SPS PDSCHs.

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, it is possible to provide a method and apparatus for decoding data of a terminal in a wireless communication system.

According to the present disclosure, it is effective to perform efficient data communication by providing a method and apparatus for decoding data by a terminal in consideration of the NTN environment.

According to the present disclosure, when a plurality of SPS PDSCHs are configured in one slot in consideration of the NTN environment, a method for selecting an SPS PDSCH to be decoded by a UE can be provided.

According to the present disclosure, it is possible to provide a method for determining HARQ feedback for each PDSCH in an NTN environment.

According to the present disclosure, there is an effect of guaranteeing data reliability by providing a method of performing data decoding based on HARQ feedback of each PDSCH in an NTN environment.

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 method of selecting an SPS PDSCH based on whether HARQ-ACK feedback is activated in an NTN environment to which the present disclosure can be applied.
13 is a diagram illustrating a method of selecting an SPS PDSCH based on whether HARQ-ACK feedback is activated in an NTN environment to which the present disclosure can be applied.
14 is a flowchart of a method for selecting an SPS PDSCH based on whether HARQ-ACK feedback is activated in an NTN environment to which the present disclosure can be applied.
15 is a flowchart of a method for selecting an SPS PDSCH based on whether HARQ-ACK feedback is activated in an NTN environment to which the present disclosure can be applied.
16 is a flowchart of a method for selecting an SPS PDSCH based on whether HARQ-ACK feedback is activated in an NTN environment to which the present disclosure can be applied.
17 is a flowchart of a method for selecting an SPS PDSCH based on whether HARQ-ACK feedback is activated in an NTN environment to which the present disclosure can be applied.
18 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,

일 수 있다. 한편, LTE에서 시간 도메인 기본 단위는

일 수 있고,

이고,

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

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

can be,

ego,

can be On the other hand, in LTE, the time domain basic unit is

can be,

ego,

can be The constant for the multiplicative relationship between NR time base units and LTE time base units is

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

또는

일 수 있다.

는 20.327μs이고,

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

는

일 수 있다. 이때,

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

or

can be

is 20.327 μs,

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

Is

can be At this time,

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 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. In particular, in the NTN environment, a scheduling method through downlink semi-persistent scheduling (DL SPS) can be effective, and a method of performing DL SPS transmission in the NTN environment will be described.

For example, when a base station performs downlink (DL) scheduling to a terminal, DL scheduling may be performed based on dynamic scheduling or semi-persistent scheduling (SPS). However, it may not be limited thereto. At this time, when DL dynamic scheduling is performed, the terminal monitors reception of a physical downlink control channel (PDCCH) including downlink control information (DCI) transmitted from the base station, and transmits scheduled DL data based on the received DCI. A physical downlink shared channel (PDSCH) may be received and decoded. That is, dynamic scheduling may be a scheduling method of a base station for UE-side reception of each PDSCH or PDSCH aggregation (PDSCH transmitted on one or more slots).

On the other hand, SPS uses higher layer signaling (e.g. RRC signaling) and DCI signaling for activation and deactivation purposes (i.e., PDCCH signaling for SPS activation (Scheduling activation) or SPS deactivation (Scheduling release)). It may be a scheme in which PDSCH transmission is performed based on scheduling (CS) scheme. For example, CS activation and deactivation may be indicated based on DCI signaling (ie, PDCCH signaling including the DCI). When the CS is activated, the terminal may receive a PDSCH carrying a new data transport block (Transport Block) from the base station at regular intervals based on the CS. That is, the terminal may receive the PDSCH based on at least one of a preset period, the number of HARQ processes, a PUCCH resource (an HARQ feedback purpose for an SPS PDSCH), and MCS table information.

PDCCH validation for the purpose of activation or deactivation of DL SPS (same as UL grant Type 2) can be determined by the terminal to be valid when the conditions shown in Table 5 below are satisfied.

[Table 5]

At this time, as an example, DL SPS configurations set based on higher layer signaling include periodicity information, hybrid automatic repeat request (HARQ) process number information, and HARQ process offset (harq-procID-offset) information, SPS configuration index (sps-configindex) information, PUCCH resource information (for HARQ feedback purposes for SPS PDSCH), HARQ codebook ID (Codebook ID), PDSCH aggregation factor, and MCS table information. there is. In addition, the DL SPS configuration may further include other information related to PDSCH transmission, and may not be limited to the above information.

In this case, as an example, a plurality of DL SPSs may be set in the UE based on the DL SPS configuration. The HARQ process ID used in each DL SPS (or configured DL assignment) may be indicated based on Equation 3 below and the HARQ process offset. Specifically, the HARQ process ID associated with one slot for starting DL transmission for each DL SPS may be determined based on Equation 3 below based on the HARQ process offset. That is, the HARQ process ID associated with one slot for starting DL transmission may be derived using the number of HARQ processes and the HARQ process offset value in consideration of the number and period of consecutive slots per frame based on the current slot. In addition, the current slot (CURRENT_slot) may be determined as shown in Equation 4 below based on the system frame number (SFN) and the number of consecutive slots per frame based on the current slot and the slot number in the current frame.

[Equation 3]

[Equation 4]

Based on the above, the terminal and the base station can derive an HARQ process ID, and based on the derived HARQ process ID, a HARQ operation for DL SPS transmission can be performed.

In addition, validation for activating or deactivating one or more DL SPS (or UL grant Type 2 scheduling) is determined based on whether the values of the specific DCI fields below are set to predetermined values indicated in Tables 6 to 9 below. can

[Table 6]

[Table 7]

[Table 8]

[Table 9]

Here, for example, in the NTN environment, a long propagation delay may occur as described above. Accordingly, the base station may set HARQ-ACK feedback (enable or disable) for each HARQ process to the terminal through higher layer signaling in consideration of the channel environment having the characteristic of long propagation delay and the QoS of the data packet. there is. That is, in the NTN environment, HARQ-ACK feedback may be set for some of the plurality of HARQ processes, and HARQ-ACK feedback may not be set for other parts. Considering the foregoing, DL SPS transmission in an NTN environment may be performed in consideration of HARQ feedback.

In this case, a case in which one or more SPS PDSCH transmissions are performed in one slot based on the DL SPS configuration may be considered. As a specific example, a case where there are a plurality of PDSCHs transmitted based on remaining symbols except for a PDSCH overlapping an uplink (UL) symbol within one slot may be considered. At this time, the UE may select and perform decoding on some SPS PDSCHs among one or more SPS PDSCHs, and may not perform decoding on the remaining SPS PDSCHs.

More specifically, the UE may perform decoding by preferentially selecting the SPS PDSCH having the lowest SPS configuration index (sps-configindex). That is, an SPS PDSCH having a low SPS configuration index can be selected and decoded.

For example, the terminal may consider the number (j) of the PDSCH selected for decoding within the set (Q) of activated SPS PDSCHs in one slot, and may be initially set to j = 0. (step 0) After that, the UE may preferentially select the SPS PDSCH having the lowest SPS configuration index (sps-configindex) in the set (Q) of SPS PDSCHs for decoding. At this time, the SPS PDSCH having the lowest SPS configuration index (sps-configindex) may be a survivor PDSCH and may be set to j = j + 1 (step 1). That is, the terminal has the lowest SPS configuration Decoding of the SPS PDSCH having an index (sps-configindex) may be performed.

After that, the UE may exclude the surviving PDSCH and other PDSCHs whose resources partially or entirely overlap with the surviving PDSCH in the time domain within the set (Q) of the SPS PDSCH. For example, the surviving PDSCH may be a PDSCH selected for decoding, and a PDSCH that may affect decoding of the surviving PDSCH (ie, a PDSCH in which resources partially or entirely overlap in the time domain) is included in the set (Q) of the SPS PDSCH Can be excluded. (step 2)

After that, the UE performs steps 1 and 2 until all PDSCHs in the SPS PDSCH set (Q) are empty or j is equal to the number of decodable unicast PDSCHs in one slot supported by the UE. can be repeated That is, when a plurality of SPS PDSCHs are configured in one slot, the terminal may select and decode some SPS PDSCHs from among the plurality of SPS PDSCHs, and may exclude some SPS PDSCHs and not decode them.

At this time, for example, when selecting an SPS PDSCH to perform decoding among the plurality of SPS PDSCHs in an NTN environment, the SPS PDSCH selection may be performed in consideration of transmission delay occurring in the NTN system and QoS of data packets.

More specifically, the NTN system needs to perform data transmission considering large transmission delay as well as QoS guarantee for data packet transmission with high reliability. Considering the above points, for example, whether HARQ-ACK feedback may be independently set for each HARQ process in an NTN environment. As a specific example, the PDSCH for which data reliability must be guaranteed may be transmitted in association with an HARQ process in which HARQ-ACK feedback is activated. On the other hand, a PDSCH in which data reliability guarantee is not relatively high and delay may occur may be transmitted in association with an HARQ process in which HARQ-ACK feedback is disabled. Through this, high reliability and low latency operation can be considered. That is, since data transmission may be affected in the NTN environment, HARQ-ACK feedback may be set for each HARQ process without setting HARQ-ACK feedback to be performed for all HARQ processes.

As a specific example, a data packet requiring high transmission/reception data reliability may enable HARQ-ACK feedback. On the other hand, HARQ-ACK feedback may be disabled in consideration of a large transmission delay occurring in an NTN environment for data packets with relatively low data reliability guarantee requirements. At this time, as an example, performance degradation may occur as HARQ-ACK feedback for data transmission is not performed. Here, a blind retransmission method for compensating for performance degradation or a data transmission method such as PDSCH/PUSCH aggregation may be additionally applied, and is not limited to the above-described embodiment.

When a plurality of SPS PDSCHs are set in one slot in consideration of the NTN environment, when a UE selects an SPS PDSCH to perform decoding, whether to activate HARQ-ACK feedback may be considered, which will be described later.

For example, a UE may be configured to receive one or more SPS PDSCHs in one serving cell within one slot. At this time, the UE may select a PDSCH for decoding based on its own data reception capability (UE capability, that is, UE capability regarding the number of PDSCHs that can be decoded in one slot) and the lowest SPS configuration index (sps-ConfigIndex). there is. For example, SPS configuration can be designed to increase the freedom of base station configuration, and based on this, a plurality of PDSCHs can be configured in one slot on the terminal as described above. Here, multiple SPS configurations and corresponding SPS PDSCH transmission/reception can be supported even in the NTN environment, and the terminal needs to perform the above operation in consideration of the NTN environment.

As an example, the method described below may be applicable not only to SPS PDSCH based on one slot but also to PDSCH aggregation transmission that can be transmitted over several slots. As another example, when PDSCH aggregation is configured, the method described below may be applied based on the first (or last) transmission slot, and may not be limited to a specific embodiment.

As an example, FIG. 12 is a diagram illustrating a method of selecting an SPS PDSCH based on whether HARQ-ACK feedback is activated in an NTN environment to which the present disclosure can be applied. A plurality of SPS PDSCHs may be configured in a UE based on one serving cell in one slot. For example, up to 8 SPS PDSCHs may be set, but may not be limited thereto.

In this case, whether to enable/disable (or activate/deactivate) HARQ-ACK feedback may be determined for each HARQ process associated with each SPS PDSCH transmission in the NTN environment as described above. That is, it may be determined whether to perform a HARQ-ACK feedback operation for each HARQ process associated with each SPS PDSCH transmission. For example, when the terminal receives the SPS PDSCH on the HARQ process in which HARC-ACK feedback is enabled, the terminal may transmit HARQ-ACK feedback to the base station. On the other hand, when the UE receives the SPS PDSCH on the HARQ process in which the HARC-ACK feedback is disabled, the UE may not transmit the HARQ-ACK feedback to the base station. That is, in an NTN environment, whether to activate HARQ-ACK feedback can be determined for each PDSCH in consideration of the delay.

Here, the terminal may select an SPS PDSCH to perform decoding with priority among a plurality of SPS PDSCHs in one slot for one serving cell as described above. For example, the UE may consider the number (j) of each PDSCH selected for decoding within the set (Q) of SPS PDSCHs activated in one slot, and may be set to j = 0. (step 0)

After that, the UE may determine the priority based on whether the HARQ-ACK feedback is related to the activated HARQ process within the set (Q) of the SPS PDSCH. Here, when an SPS PDSCH associated with an HARQ process in which at least one HARQ-ACK feedback is activated is configured in one slot, the UE selects an SPS configuration index (sps-ConfigIndex ) may be preferentially decoded by selecting the lowest SPS PDSCH. On the other hand, when the SPS PDSCH associated with the HARQ process in which HARQ-ACK feedback is activated does not exist in one slot, the UE has the lowest SPS configuration index (sps) among the remaining SPS PDSCHs associated with the HARQ process in which HARQ-ACK feedback is inactive -ConfigIndex) can be decoded by preferentially selecting the SPS PDSCH. (step 1)

Then, j=j+1 may be set, and the selected SPS PDSCH may be determined as a survivor PDSCH. At this time, as an example, other SPS PDSCHs that partially or entirely overlap with the surviving SPS PDSCH in resources in the time domain may be excluded from the SPS PDSCH set (Q). (step 2)

After that, the UE repeats steps 1 and 2 until all PDSCHs in the SPS PDSCH set (Q) are empty or j is equal to the number of decodable unicast PDSCHs in one slot supported by the UE. can do. (step 3)

That is, when a plurality of SPS PDSCHs are set in one slot, the terminal may select and decode some SPS PDSCHs from among the plurality of SPS PDSCHs, and may exclude some SPS PDSCHs and not decode them.

That is, when the terminal selects the SPS PDSCH to perform decoding in the NTN environment as described above, the terminal may first determine whether or not there is an SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is enabled. Here, SPS PDSCHs associated with an HARQ process in which HARQ-ACK feedback is activated in the SPS PDSCH set (Q) may be selected prior to SPS PDSCHs associated with an HARQ process in which HARQ-ACK feedback is inactivated. The UE may first select and decode the SPS PDSCH having the lowest SPS configuration index (sps-ConfigIndex) among the SPS PDSCHs associated with the HARQ process in which the HARQ-ACK feedback is activated. On the other hand, if there is no HARQ-ACK feedback associated with an HARQ process in which HARQ-ACK feedback is activated in one slot, the UE may perform decoding by selecting an SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is deactivated. there is. The UE may first select and decode the SPS PDSCH having the lowest SPS configuration index (sps-ConfigIndex) among the SPS PDSCHs associated with the HARQ process in which the HARQ-ACK feedback is disabled.

As a more specific example, referring to FIG. 12 , four SPS PDSCHs 1210, 1220, 1230, and 1240 may be configured. For example, up to 8 SPS PDSCHs may be set, but may not be limited thereto. In this case, whether or not HARQ-ACK feedback may be determined based on an HARQ process associated with each SPS PDSCH configured in one slot in an NTN environment, and may be shown in Table 10 below.

[Table 10]

That is, in FIG. 12, SPS#0 1210 is associated with HP#0 in which HARQ-ACK feedback is disabled, SPS#1 1220 is associated with HP#1 in which HARQ-ACK feedback is activated, and SPS#2 1230 may be associated with HP#2 in which HARQ-ACK feedback is disabled, and SPS#3 1230 may be associated with HP#3 in which HARQ-ACK feedback is disabled. Here, in FIG. 12, SPS#0 (1210) and SPS#1 (1220) overlap in the time domain, and SPS#2 (1230) and SPS#3 (1240) overlap in the time domain. can However, this is only one example and is not limited to the above-described embodiment. Here, when the UE selects the SPS PDSCH to perform decoding from the SPS PDSCH set (Q) based on the above, the UE selects one SPS related to the HARQ process in which the HARQ-ACK feedback is activated based on step 1 It can be determined whether or not it exists in the slot. For example, SPS #1 1220 and SPS #2 1230 may be associated with an HARQ process in which HARQ-ACK feedback is activated. Accordingly, the terminal may prioritize selection of SPS #1 1220 and SPS #2 1230 over SPS #0 1210 and SPS #3 1240 . At this time, the terminal may select SPS#1 1220 having a low SPS configuration index as the SPS PDSCH to perform decoding. Then, j=j+1 may be set, and the selected SPS PDSCH (i.e. SPS#1) may be determined as the surviving PDSCH. Thereafter, the UE may exclude SPS#0 1210, which partially or entirely overlaps with the selected survivor PDSCH in resources in the time domain, from the SPS PDSCH set (Q). After that, the terminal can repeat the above step 1 and step 2. At this time, the terminal determines SPS#2 1230 associated with the HARQ process in which HARQ-ACK feedback is activated as an additional surviving PDSCH, and SPS#3 overlaps in part or in whole with SPS#2 1230 in resources in the time domain. (1240) can be excluded. After that, since the SPS PDSCH set (Q) is empty, the UE finally decodes the SPS PDSCHs corresponding to SPS#1 1220 and SPS#2 1230, and does not decode the remaining SPS PDSCHs. can drop

As an example, FIG. 13 is a diagram illustrating a method of selecting an SPS PDSCH based on whether HARQ-ACK feedback is activated in an NTN environment to which the present disclosure can be applied. A plurality of SPS PDSCHs may be configured in a UE based on one serving cell in one slot. For example, up to 8 SPS PDSCHs may be set, but may not be limited thereto.

In this case, whether to enable/disable (or activate/deactivate) HARQ-ACK feedback may be determined for each HARQ process associated with each SPS PDSCH transmission in the NTN environment as described above. That is, it may be determined whether to perform a HARQ-ACK feedback operation for each HARQ process associated with each SPS PDSCH transmission. For example, when the terminal receives the SPS PDSCH on the HARQ process in which HARC-ACK feedback is enabled, the terminal may transmit HARQ-ACK feedback to the base station. On the other hand, when the UE receives the SPS PDSCH on the HARQ process in which the HARC-ACK feedback is disabled, the UE may not transmit the HARQ-ACK feedback to the base station. That is, in an NTN environment, whether to activate HARQ-ACK feedback can be determined for each PDSCH in consideration of the delay.

Here, the terminal may select an SPS PDSCH to perform decoding with priority among a plurality of SPS PDSCHs in one slot for one serving cell as described above. For example, the UE may consider the number (j) of each PDSCH selected for decoding within the set (Q) of SPS PDSCHs activated in one slot, and may be set to j = 0. (step 0)

After that, the UE may determine the priority based on whether the HARQ-ACK feedback is related to the activated HARQ process within the set (Q) of the SPS PDSCH. Here, when an SPS PDSCH associated with an HARQ process in which at least one HARQ-ACK feedback is activated is configured in one slot, the UE selects an SPS configuration index (sps-ConfigIndex ) may be preferentially decoded by selecting the lowest SPS PDSCH. On the other hand, when the SPS PDSCH with activated HARQ-ACK feedback does not exist in one slot, the UE selects the lowest SPS configuration index (sps-ConfigIndex) among the remaining SPS PDSCHs associated with the HARQ process with deactivated HARQ-ACK feedback. It is possible to decode by preferentially selecting the SPS PDSCH having (step 1)

Then, j=j+1 may be set, and the selected SPS PDSCH may be determined as a survivor PDSCH. In this case, as an example, other SPS PDSCHs that partially or entirely overlap with the surviving SPS PDSCH in resources in the time domain may be excluded from the SPS PDSCH set (Q). However, as an example, if there is an SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is activated among other SPS PDSCHs that partially or entirely overlap with the surviving SPS PDSCH in resources in the time domain, the corresponding SPS PDSCH is an SPS PDSCH set ( Q) may not be excluded. (step 2) For example, in the case of an SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is activated among SPS PDSCHs, it may not be excluded from the SPS PDSCH set (Q) as described above to ensure data reliability.

After that, the UE repeats steps 1 and 2 until all PDSCHs in the SPS PDSCH set (Q) are empty or j is equal to the number of decodable unicast PDSCHs in one slot supported by the UE. can do. (step 3)

That is, when a plurality of SPS PDSCHs are set in one slot, the terminal may select and decode some SPS PDSCHs from among the plurality of SPS PDSCHs, and may exclude some SPS PDSCHs and not decode them.

That is, when the terminal selects the SPS PDSCH to perform decoding in the NTN environment as described above, the terminal may first determine whether or not there is an SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is enabled. Here, SPS PDSCHs associated with an HARQ process in which HARQ-ACK feedback is activated in the SPS PDSCH set (Q) may be selected prior to SPS PDSCHs associated with an HARQ process in which HARQ-ACK feedback is inactivated. The UE may first select and decode the SPS PDSCH having the lowest SPS configuration index (sps-ConfigIndex) among the SPS PDSCHs associated with the HARQ process in which the HARQ-ACK feedback is activated. On the other hand, if there is no HARQ-ACK feedback associated with an HARQ process in which HARQ-ACK feedback is activated in one slot, the UE may perform decoding by selecting an SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is deactivated. there is. Here, the UE may first select and decode the SPS PDSCH having the lowest SPS configuration index (sps-ConfigIndex) among the SPS PDSCHs associated with the HARQ process in which the HARQ-ACK feedback is disabled.

As a more specific example, referring to FIG. 13 , four SPS PDSCHs 1310, 1320, 1330, and 1340 may be configured. For example, up to 8 SPS PDSCHs may be set, but may not be limited thereto. At this time, whether or not HARQ-ACK feedback may be determined based on the HARQ process associated with each SPS PDSCH configured in one slot in the NTN environment, and may be as shown in Table 5 above.

That is, in FIG. 13, SPS#0 1310 is associated with HP#0 in which HARQ-ACK feedback is disabled, SPS#1 1320 is associated with HP#1 in which HARQ-ACK feedback is activated, and SPS#2 1330 may be associated with HP#2 in which HARQ-ACK feedback is disabled, and SPS#3 1330 may be associated with HP#3 in which HARQ-ACK feedback is disabled.

For example, in FIG. 13, SPS#0 (1310) and SPS#1 (1320) overlap in the time domain, and SPS#1 (1320) and SPS#2 (1330) overlap in the time domain. It can be. However, this is only one example and is not limited to the above-described embodiment. Here, when the UE selects the SPS PDSCH to perform decoding from the SPS PDSCH set (Q) based on the above, the UE selects one SPS related to the HARQ process in which the HARQ-ACK feedback is activated based on step 1 It can be determined whether or not it exists in the slot. For example, SPS #1 1320 and SPS #2 1330 may be associated with an HARQ process in which HARQ-ACK feedback is activated. Accordingly, the terminal may prioritize selection of SPS #1 1320 and SPS #2 1330 over SPS #0 1310 and SPS #3 1340 . At this time, the terminal may select SPS #1 1320 having a low SPS configuration index as the SPS PDSCH to perform decoding. Then, j=j+1 may be set, and the selected SPS PDSCH (i.e. SPS#1) may be determined as the surviving PDSCH. Thereafter, the UE may exclude an SPS PDSCH partially or entirely overlapping with the selected survivor PDSCH in time domain resources from the SPS PDSCH set (Q). Here, SPS PDCSHs that partially or entirely overlap with SPS#1 1320 in time domain resources may be SPS#0 1310 and SPS#2 1320. At this time, among the SPS PDCSHs, SPS#0 1310 may be an SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is disabled, and SPS#2 1330 may be an SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is activated. can be Since SPS#0 1310 is an SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is disabled, it can be excluded from the SPS PDSCH set (Q). On the other hand, since SPS#2 1330 is an SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is activated, it may not be excluded from the SPS PDSCH set (Q).

After that, the terminal can repeat the above step 1 and step 2. At this time, since SPS#2 1330 associated with the HARQ process in which HARQ-ACK feedback is activated is not excluded from the SPS PDSCH set (Q), the UE uses SPS#2 1330 in a repetitive operation as HARQ-ACK feedback is inactivated. It may be selected prior to SPS#3 1340 associated with the HARQ process. Accordingly, the UE may determine SPS # 2 1330 associated with the HARQ process in which HARQ-ACK feedback is activated as an additional surviving PDSCH. Thereafter, the UE may exclude the SPS PDSCH that partially or entirely overlaps SPS#2 1330 and resources in the time domain.

Here, as an example, the terminal may be a terminal capable of decoding two PDSCHs, and since SPS#1 (1320) and SPS#2 (1330) are selected, finally SPS#1 (1320) and SPS#2 (1330) Corresponding SPS PDSCHs may be decoded, and the remaining SPS PDSCHs may be dropped without decoding.

As another example, when the UE is capable of decoding three PDSCHs, the UE may repeat steps 1 and 2 above. At this time, SPS#3 1340 may be an SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is disabled, but is not excluded due to time resource overlap, so the UE uses SPS#1 1320 and SPS#2 1330 In addition, SPS#3 1340 can be selected, and is not limited to the above-described embodiment.

As another example, a plurality of SPS PDSCHs may be configured in a UE based on one serving cell in one slot. For example, up to 8 SPS PDSCHs may be set, but may not be limited thereto.

In this case, whether to enable/disable (or activate/deactivate) HARQ-ACK feedback may be determined for each HARQ process associated with each SPS PDSCH transmission in the NTN environment as described above. That is, whether or not to perform the HARQ-ACK feedback operation may be determined based on the HARQ process associated with each HARQ process associated with each SPS PDSCH transmission. For example, when the terminal receives the SPS PDSCH on the HARQ process in which HARC-ACK feedback is enabled, the terminal may transmit HARQ-ACK feedback to the base station. On the other hand, when the UE receives the SPS PDSCH on the HARQ process in which the HARC-ACK feedback is disabled, the UE may not transmit the HARQ-ACK feedback to the base station. That is, in an NTN environment, whether to activate HARQ-ACK feedback can be determined for each PDSCH in consideration of the delay.

Here, the terminal may select an SPS PDSCH to perform decoding with priority among a plurality of SPS PDSCHs in one slot for one serving cell as described above. For example, the UE may consider the number (j) of each PDSCH selected for decoding within the set (Q) of SPS PDSCHs activated in one slot, and may be set to j = 0. (step 0)

After that, the UE may determine the priority based on whether the HARQ-ACK feedback is related to the activated HARQ process within the set (Q) of the SPS PDSCH. Here, when an SPS PDSCH associated with an HARQ process in which at least one HARQ-ACK feedback is activated is configured in one slot, the UE receives the lowest HARQ process ID (or HARQ process index) may be preferentially decoded by selecting the SPS PDSCH associated with the HARQ process. That is, the SPS PDSCH corresponding to the HARQ process having the lowest HARQ process ID may be selected. On the other hand, when the SPS PDSCH with activated HARQ-ACK feedback does not exist in one slot, the UE has the lowest HARQ process ID (or HARQ process index) among the remaining SPS PDSCHs associated with the HARQ process with deactivated HARQ-ACK feedback. It is possible to preferentially decode by selecting the SPS PDSCH associated with the HARQ process having . That is, the SPS PDSCH corresponding to the HARQ process having the lowest HARQ process ID may be selected. (step 1)

Then, j=j+1 may be set, and the selected SPS PDSCH may be determined as a survivor PDSCH. At this time, as an example, other SPS PDSCHs that partially or entirely overlap with the surviving SPS PDSCH in resources in the time domain may be excluded from the SPS PDSCH set (Q). (step 2)

After that, the UE repeats steps 1 and 2 until all PDSCHs in the SPS PDSCH set (Q) are empty or j is equal to the number of decodable unicast PDSCHs in one slot supported by the UE. can do. (step 3)

That is, when a plurality of SPS PDSCHs are set in one slot, the terminal may select and decode some SPS PDSCHs from among the plurality of SPS PDSCHs, and may exclude some SPS PDSCHs and not decode them. That is, when the terminal selects the SPS PDSCH to perform decoding in the NTN environment as described above, the terminal may first determine whether or not there is an SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is enabled. Here, SPS PDSCHs associated with an HARQ process in which HARQ-ACK feedback is activated in the SPS PDSCH set (Q) may be selected prior to SPS PDSCHs associated with an HARQ process in which HARQ-ACK feedback is inactivated. Here, the UE may select and decode the SPS PDSCH associated with the HARQ process having the lowest HARQ process ID (or HARQ process index) among the SPS PDSCHs associated with the HARQ process in which HARQ-ACK feedback is activated. On the other hand, if there is no HARQ-ACK feedback associated with an HARQ process in which HARQ-ACK feedback is activated in one slot, the UE may perform decoding by selecting an SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is deactivated. there is. Here, the UE may select and decode the SPS PDSCH associated with the HARQ process having the lowest HARQ process ID (or HARQ process index) among the SPS PDSCHs associated with the HARQ process in which HARQ-ACK feedback is disabled.

As a more specific example, 4 SPS PDSCHs may be configured based on Table 5 above. For example, up to 8 SPS PDSCHs may be set, but may not be limited thereto. At this time, whether or not HARQ-ACK feedback may be determined for each SPS PDSCH configured in one slot in the NTN environment, and may be as shown in Table 5 above.

SPS#0 is associated with HP#0 with HARQ-ACK feedback disabled, SPS#1 is associated with HP#1 with HARQ-ACK feedback enabled, and SPS#2 is associated with HP#2 with HARQ-ACK feedback disabled. , and SPS#3 may be associated with HP#3 in which HARQ-ACK feedback is disabled. Here, as an example, SPS#0 and SPS#1 may overlap in the time domain, and SPS#2 and SPS#3 may overlap in the time domain. However, this is only one example and is not limited to the above-described embodiment. Here, when the UE selects the SPS PDSCH to perform decoding from the SPS PDSCH set (Q) based on the above, the UE selects one SPS related to the HARQ process in which the HARQ-ACK feedback is activated based on step 1 It can be determined whether or not it exists in the slot. For example, SPS #1 and SPS #2 may be associated with an HARQ process in which HARQ-ACK feedback is activated. Accordingly, the terminal may select SPS #1 and SPS #2 prior to SPS #0 and SPS #3. At this time, the terminal may compare the HARQ process ID (or HARQ process index). For example, the UE may select an SPS associated with an HARQ process having the lowest HARQ process ID. Accordingly, the UE may select SPS #1 1220 associated with the HARQ process having HP#1 as the SPS PDSCH to perform decoding. Then, j=j+1 may be set, and the selected SPS PDSCH (i.e. SPS#1) may be determined as the surviving PDSCH. Thereafter, the UE may exclude SPS#0, which partially or entirely overlaps with the selected survivor PDSCH in resources in the time domain, from the SPS PDSCH set (Q). After that, the terminal can repeat the above step 1 and step 2. At this time, the terminal determines SPS#2 associated with the HARQ process in which HARQ-ACK feedback is activated as an additional surviving PDSCH, and excludes SPS#3 1240, which partially or entirely overlaps with SPS#2 in resources in the time domain. can After that, since the SPS PDSCH set (Q) is empty, the UE can finally decode the SPS PDSCHs corresponding to SPS#1 and SPS#2, and drop the remaining SPS PDSCHs without decoding them.

As another example, a plurality of SPS PDSCHs may be configured in a terminal based on one serving cell in one slot. For example, up to 8 SPS PDSCHs may be set, but may not be limited thereto.

In this case, whether to enable/disable (or activate/deactivate) HARQ-ACK feedback may be determined for each HARQ process associated with each SPS PDSCH transmission in the NTN environment as described above. That is, it may be determined whether to perform a HARQ-ACK feedback operation for each HARQ process associated with each SPS PDSCH transmission. For example, when the terminal receives the SPS PDSCH on the HARQ process in which HARC-ACK feedback is enabled, the terminal may transmit HARQ-ACK feedback to the base station. On the other hand, when the UE receives the SPS PDSCH on the HARQ process in which the HARC-ACK feedback is disabled, the UE may not transmit the HARQ-ACK feedback to the base station. That is, in an NTN environment, whether to activate HARQ-ACK feedback can be determined for each PDSCH in consideration of the delay.

Here, the terminal may select an SPS PDSCH to perform decoding with priority among a plurality of SPS PDSCHs in one slot for one serving cell as described above. For example, the UE may consider the number (j) of each PDSCH selected for decoding within the set (Q) of SPS PDSCHs activated in one slot, and may be set to j = 0. (step 0)

After that, the UE may determine the priority based on whether the HARQ-ACK feedback is related to the activated HARQ process within the set (Q) of the SPS PDSCH. Here, the UE may select and decode the SPS PDSCH associated with the HARQ process having the lowest HARQ process ID (or HARQ process index) among the SPS PDSCHs associated with the HARQ process associated with the HARQ process in which HARQ-ACK feedback is activated. there is. On the other hand, when the SPS PDSCH associated with the HARQ process in which HARQ-ACK feedback is activated does not exist in one slot, the UE receives the lowest HARQ process ID (or HARQ Process index) may be preferentially decoded by selecting the SPS PDSCH associated with the HARQ process. (step 1)

Then, j=j+1 may be set, and the selected SPS PDSCH may be determined as a survivor PDSCH. At this time, as an example, other SPS PDSCHs that partially or entirely overlap with the surviving SPS PDSCH in resources in the time domain may be excluded from the SPS PDSCH set (Q). However, as an example, if there is an SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is activated among other SPS PDSCHs that partially or entirely overlap with the surviving SPS PDSCH in resources in the time domain, the corresponding SPS PDSCH is an SPS PDSCH set ( Q) may not be excluded. (step 2)

For example, in the case of an SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is activated among SPS PDSCHs, as described above, in order to guarantee data reliability, it may not be excluded from the SPS PDSCH set (Q). After that, the UE repeats steps 1 and 2 until all PDSCHs in the SPS PDSCH set (Q) are empty or j is equal to the number of decodable unicast PDSCHs in one slot supported by the UE. can do. (step 3)

That is, when a plurality of SPS PDSCHs are set in one slot, the terminal may select and decode some SPS PDSCHs from among the plurality of SPS PDSCHs, and may exclude some SPS PDSCHs and not decode them. As described above, when the UE selects the SPS PDSCH to perform decoding in the NTN environment, the UE may preferentially determine whether or not there is an SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is enabled. Here, SPS PDSCHs associated with an HARQ process in which HARQ-ACK feedback is activated in the SPS PDSCH set (Q) may be selected prior to SPS PDSCHs associated with an HARQ process in which HARQ-ACK feedback is inactivated. Here, the UE may select and decode the SPS PDSCH associated with the HARQ process having the lowest HARQ process ID (or HARQ process index) among the SPS PDSCHs associated with the HARQ process in which HARQ-ACK feedback is activated.

On the other hand, if there is no HARQ-ACK feedback associated with an HARQ process in which HARQ-ACK feedback is activated in one slot, the UE may perform decoding by selecting an SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is deactivated. there is. Here, the UE may select and decode the SPS PDSCH associated with the HARQ process having the lowest HARQ process ID (or HARQ process index) among the SPS PDSCHs associated with the HARQ process in which HARQ-ACK feedback is disabled.

As a more specific example, 4 SPS PDSCHs may be configured based on Table 5 above. For example, up to 8 SPS PDSCHs may be set, but may not be limited thereto. At this time, whether or not HARQ-ACK feedback may be determined for each SPS PDSCH configured in one slot in the NTN environment, and may be as shown in Table 5 above.

That is, SPS#0 is associated with HP#0 with HARQ-ACK feedback disabled, SPS#1 is associated with HP#1 with HARQ-ACK feedback enabled, and SPS#2 is associated with HP with HARQ-ACK feedback disabled. It is associated with #2, and SPS#3 can be associated with HP#3 in which HARQ-ACK feedback is disabled.

Here, SPS#0 and SPS#1 may overlap in the time domain, and SPS#1 and SPS#2 may overlap in the time domain. However, this is only one example and is not limited to the above-described embodiment. When the UE selects an SPS PDSCH to perform decoding from the SPS PDSCH set (Q), the UE determines whether SPSs associated with an HARQ process in which HARQ-ACK feedback is activated are present in one slot based on step 1 can do. For example, SPS #1 and SPS #2 may be associated with an HARQ process in which HARQ-ACK feedback is activated. Accordingly, the terminal may select SPS #1 and SPS #2 prior to SPS #0 and SPS #3.

At this time, the terminal may compare the HARQ process ID (or HARQ process index). For example, the UE may select an SPS associated with an HARQ process having the lowest HARQ process ID. Accordingly, the UE may select SPS#1 associated with the HARQ process having HP#1, which is the lowest HARQ process ID, as the SPS PDSCH to perform decoding. Then, j=j+1 may be set, and the selected SPS PDSCH (i.e. SPS#1) may be determined as the surviving PDSCH. Thereafter, the UE may exclude an SPS PDSCH partially or entirely overlapping with the selected survivor PDSCH in time domain resources from the SPS PDSCH set (Q). Here, SPS PDCSHs that partially or entirely overlap with SPS#1 in time domain resources may be SPS#0 and SPS#2. In this case, among the SPS PDCSHs, SPS#0 may be an SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is disabled, and SPS#2 may be an SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is activated. Therefore, since SPS#0 is an SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is disabled, it can be excluded from the SPS PDSCH set (Q). On the other hand, since SPS#2 is an SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is activated, it may not be excluded from the SPS PDSCH set (Q).

After that, the terminal can repeat the above step 1 and step 2. At this time, since SPS#2 associated with the HARQ process in which HARQ-ACK feedback is activated is not excluded from the SPS PDSCH set (Q), the UE uses SPS#2 in repetitive operation as SPS# associated with the HARQ process in which HARQ-ACK feedback is inactivated. You can choose in preference to 3. Accordingly, the UE may determine SPS#2 associated with the HARQ process in which HARQ-ACK feedback is activated as an additional surviving PDSCH. After that, the UE may exclude the SPS PDSCH that partially or entirely overlaps SPS#2 and resources in the time domain.

Here, as an example, the terminal may be a terminal capable of decoding two PDSCHs, and since SPS#1 and SPS#2 are selected, finally decoding the SPS PDSCHs corresponding to SPS#1 and SPS#2 is performed, The remaining SPS PDSCHs may be dropped without decoding.

As another example, when the UE is capable of decoding three PDSCHs, the UE may repeat steps 1 and 2 above. In this case, SPS#3 may be an SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is disabled, but is not excluded due to time resource overlap, so the UE may select SPS#3 in addition to SPS#1 and SPS#2, , It is not limited to the above-described embodiment.

14 is a flowchart of a method for selecting an SPS PDSCH based on whether HARQ-ACK feedback is activated in an NTN environment to which the present disclosure can be applied.

Referring to FIG. 14, a plurality of SPS PDSCHs may be configured for one serving cell in one slot in a terminal. The terminal may check an SPS PDSCH set (Q) including a plurality of SPS PDSCHs for one serving cell in one slot. (S1410) At this time, as an example, in the NTN environment, HARQ- Whether to apply ACK feedback may be determined, and whether to perform SPS PDSCH decoding may be determined based on whether the HARQ-ACK feedback is an SPS PDSCH associated with an activated HARQ process.

More specifically, the UE may check whether or not there is at least one SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is activated in the SPS PDSCH set (Q) (S1420). At this time, HARQ-ACK feedback is activated If there is at least one SPS PDSCH associated with the HARQ process, the UE can check at least one SPS PDSCH associated with the HARQ process in which HARQ-ACK feedback is activated among the SPS PDSCHs in the SPS PDSCH set (Q). ( S1430) In addition, the terminal may set j = 0, and j may be the number of the PDSCH selected for decoding. Thereafter, the UE may select, as the surviving PDSCH, an SPS PDSCH having the lowest SPS configuration index among at least one SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is activated (S1440). That is, the UE provides HARQ-ACK feedback Excluding the SPS PDSCHs associated with the deactivated HARQ process, among the SPS PDSCHs associated with the HARQ process in which HARQ-ACK feedback is activated, the SPS PDSCH having the lowest SPS configuration index may be selected as the surviving PDSCH. Thereafter, the UE may exclude an SPS PDSCH in which some or all of the resources in the time domain overlap with the surviving PDSCH from the SPS PDSCH set (Q) (S1450). As an example, some or all of the selected PDSCH and resources in the time domain In the case of overlapping, since PDSCH reception may be affected, overlapping PDSCHs may be excluded, as described above. Then, j=j+1 may be set. At this time, the terminal may determine whether the SPS PDSCH set (Q) is empty or j is equal to the number of unicast PDSCHs decodable in one slot. (S1490)

As another example, a case where the UE determines that at least one SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is activated in the SPS PDSCH set (Q) does not exist (S1420) may be considered. That is, it may be considered that only at least one SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is disabled exists in the SPS PDSCH set (Q). At this time, the UE may check at least one SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is disabled among the SPS PDSCHs in the SPS PDSCH set (Q) (S1460). Thereafter, the UE may select, as the surviving PDSCH, the SPS PDSCH having the lowest SPS configuration index among at least one SPS PDSCH associated with the HARQ process in which the HARQ-ACK feedback is disabled. (S1470) SPS PDSCHs in which resources in the time domain partially or entirely overlap may be excluded from the SPS PDSCH set (Q). (S1480)

That is, the UE may preferentially select SPS PDSCHs associated with an HARQ process in which HARQ-ACK feedback is activated from the SPS PDSCH set (Q), as described above.

Then, when the SPS PDSCH set (Q) is empty or when j is equal to the number of unicast PDSCHs decodable in one slot, the UE can decode the selected SPS PDSCHs. On the other hand, if the SPS PDSCH set (Q) is not empty or if j is not equal to the number of unicast PDSCHs decodable in one slot, the UE checks the SPS PDSCHs in the SPS PDSCH set (Q) and repeats the above-described operation can do.

15 is a flowchart of a method for selecting an SPS PDSCH based on whether HARQ-ACK feedback is activated in an NTN environment to which the present disclosure can be applied.

Referring to FIG. 15, a plurality of SPS PDSCHs may be configured for one serving cell in one slot in a terminal. The terminal may check the SPS PDSCH set (Q) including a plurality of SPS PDSCHs for one serving cell in one slot. (S1510) At this time, for example, in the NTN environment, whether HARQ-ACK feedback is applied for each PDSCH may be determined, and whether to perform SPS PDSCH decoding may be determined based on whether the HARQ-ACK feedback is an SPS PDSCH associated with an activated HARQ process.

More specifically, the UE may check whether or not there is at least one SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is activated in the SPS PDSCH set (Q) (S1520). At this time, HARQ-ACK feedback is activated If there is at least one SPS PDSCH associated with the HARQ process, the UE can check at least one SPS PDSCH associated with the HARQ process in which HARQ-ACK feedback is activated among the SPS PDSCHs in the SPS PDSCH set (Q). ( S1530) In addition, the terminal may set j = 0, and j may be the number of the PDSCH selected for decoding. Thereafter, the UE may select, as the surviving PDSCH, an SPS PDSCH having the lowest SPS configuration index among at least one SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is activated (S1540). That is, the UE provides HARQ-ACK feedback Excluding the SPS PDSCHs associated with the deactivated HARQ process, among the SPS PDSCHs associated with the HARQ process in which HARQ-ACK feedback is activated, the SPS PDSCH having the lowest SPS configuration index may be selected as the surviving PDSCH. Thereafter, the UE may exclude an SPS PDSCH in which resources in the time domain partially or entirely overlap with the surviving PDSCH, from the SPS PDSCH set (Q). At this time, as an example, the UE may exclude from the SPS PDSCH set (Q) only the SPS PDSCH associated with the HARQ process in which the HARQ-ACK feedback is disabled among the SPS PDSCHs in which resources in the time domain partially or entirely overlap with the surviving PDSCH. . That is, among the SPS PDSCHs in which resources in the time domain partially or entirely overlap with the surviving PDSCH, only the SPS PDSCH associated with the HARQ process in which the HARQ-ACK feedback is activated is not excluded from the SPS PDSCH set (Q), and is selected in the next selection process It can be. Then, j=j+1 may be set. At this time, the terminal may determine whether the SPS PDSCH set (Q) is empty or j is equal to the number of unicast PDSCHs decodable in one slot. (S1590)

As another example, a case where the UE determines that at least one SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is activated does not exist in the SPS PDSCH set (Q) (S1520) may be considered. That is, it may be considered that only at least one SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is disabled exists in the SPS PDSCH set (Q). At this time, the UE may check at least one SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is disabled among the SPS PDSCHs in the SPS PDSCH set (Q) (S1560). Thereafter, the UE may select, as the surviving PDSCH, the SPS PDSCH having the lowest SPS configuration index among at least one SPS PDSCH associated with the HARQ process in which the HARQ-ACK feedback is disabled. (S1570) SPS PDSCHs in which resources in the time domain partially or entirely overlap may be excluded from the SPS PDSCH set (Q) (S1580). SPS PDSCHs can be selected with priority, as described above.

Then, when the SPS PDSCH set (Q) is empty or when j is equal to the number of unicast PDSCHs decodable in one slot, the UE can decode the selected SPS PDSCHs. On the other hand, if the SPS PDSCH set (Q) is not empty or if j is not equal to the number of unicast PDSCHs decodable in one slot, the UE checks the SPS PDSCHs in the SPS PDSCH set (Q) and repeats the above-described operation can do.

16 is a flowchart of a method for selecting an SPS PDSCH based on whether HARQ-ACK feedback is activated in an NTN environment to which the present disclosure can be applied.

Referring to FIG. 16, a plurality of SPS PDSCHs may be configured for one serving cell in one slot in a terminal. The terminal may check the SPS PDSCH set (Q) including a plurality of SPS PDSCHs for one serving cell in one slot. (S1610) At this time, as an example, in the NTN environment, whether or not HARQ-ACK feedback is applied for each PDSCH may be determined, and whether to perform SPS PDSCH decoding may be determined based on whether the HARQ-ACK feedback is an SPS PDSCH associated with an activated HARQ process.

More specifically, the UE may check whether or not there is at least one SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is activated in the SPS PDSCH set (Q) (S1620). At this time, HARQ-ACK feedback is activated If there is at least one SPS PDSCH associated with the HARQ process, the UE can check at least one SPS PDSCH associated with the HARQ process in which HARQ-ACK feedback is activated among the SPS PDSCHs in the SPS PDSCH set (Q). ( S1630) In addition, the terminal may set j = 0, and j may be the number of the PDSCH selected for decoding. Thereafter, the UE may select an SPS PDSCH associated with the HARQ process having the lowest HARQ process ID (or HARQ process index) among at least one SPS PDSCH associated with the HARQ process in which HARQ-ACK feedback is activated as the surviving PDSCH. (S1640) That is, the UE has the lowest HARQ process ID (or HARQ process index) among SPS PDSCHs associated with an HARQ process in which HARQ-ACK feedback is activated, except for SPS PDSCHs associated with an HARQ process in which HARQ-ACK feedback is inactivated. The SPS PDSCH associated with the HARQ process having can be selected as the surviving PDSCH. Thereafter, the UE may exclude an SPS PDSCH in which some or all of resources in the time domain overlap with the surviving PDSCH from the SPS PDSCH set (Q) (S1650). As an example, some or all of the selected PDSCH and resources in the time domain In the case of overlapping, since PDSCH reception may be affected, overlapping PDSCHs may be excluded, as described above. Then, j=j+1 may be set. At this time, the terminal may determine whether the SPS PDSCH set (Q) is empty or j is equal to the number of unicast PDSCHs decodable in one slot. (S1690)

As another example, a case where the UE determines that at least one SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is activated in the SPS PDSCH set (Q) does not exist (S1620) may be considered. That is, it may be considered that only at least one SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is disabled exists in the SPS PDSCH set (Q). At this time, the UE may check at least one SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is disabled among the SPS PDSCHs in the SPS PDSCH set (Q) (S1660). After that, the UE may select the SPS PDSCH associated with the HARQ process having the lowest HARQ process ID (or HARQ process index) among at least one SPS PDSCH associated with the HARQ process in which HARQ-ACK feedback is disabled as the surviving PDSCH. (S1670) After that, the UE may exclude an SPS PDSCH whose resources in the time domain partially or entirely overlap with the surviving PDSCH from the SPS PDSCH set (Q). (S1680) That is, the UE selects from the SPS PDSCH set (Q) SPS PDSCHs associated with an HARQ process in which HARQ-ACK feedback is activated may be selected with priority, as described above.

Then, when the SPS PDSCH set (Q) is empty or when j is equal to the number of unicast PDSCHs decodable in one slot, the UE can decode the selected SPS PDSCHs. On the other hand, if the SPS PDSCH set (Q) is not empty or if j is not equal to the number of unicast PDSCHs decodable in one slot, the UE checks the SPS PDSCHs in the SPS PDSCH set (Q) and repeats the above-described operation can do.

17 is a flowchart of a method for selecting an SPS PDSCH based on whether HARQ-ACK feedback is activated in an NTN environment to which the present disclosure can be applied.

Referring to FIG. 17, a plurality of SPS PDSCHs may be configured for one serving cell in one slot in a terminal. The terminal may check the SPS PDSCH set (Q) including a plurality of SPS PDSCHs for one serving cell in one slot. (S1710) At this time, for example, in the NTN environment, whether HARQ-ACK feedback is applied for each PDSCH may be determined, and whether to perform SPS PDSCH decoding may be determined based on whether the HARQ-ACK feedback is an SPS PDSCH associated with an activated HARQ process.

More specifically, the UE may check whether or not there is at least one SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is activated in the SPS PDSCH set (Q) (S1720). At this time, HARQ-ACK feedback is activated If there is at least one SPS PDSCH associated with the HARQ process, the UE can check at least one SPS PDSCH associated with the HARQ process in which HARQ-ACK feedback is activated among the SPS PDSCHs in the SPS PDSCH set (Q). ( S1730) In addition, the terminal may set j = 0, and j may be the number of the PDSCH selected for decoding. Thereafter, the UE may select an SPS PDSCH associated with the HARQ process having the lowest HARQ process ID (or HARQ process index) among at least one SPS PDSCH associated with the HARQ process in which HARQ-ACK feedback is activated as the surviving PDSCH. (S1740) That is, the UE is associated with an HARQ process in which HARQ-ACK feedback is disabled among SPS PDSCHs associated with an HARQ process in which HARQ-ACK feedback is activated, except for SPS PDSCHs associated with an HARQ process in which HARQ-ACK feedback is deactivated. At least one SPS PDSCH can be selected. Thereafter, the UE may exclude an SPS PDSCH in which resources in the time domain partially or entirely overlap with the surviving PDSCH, from the SPS PDSCH set (Q). At this time, as an example, the UE may exclude from the SPS PDSCH set (Q) only the SPS PDSCH associated with the HARQ process in which the HARQ-ACK feedback is disabled among the SPS PDSCHs in which resources in the time domain partially or entirely overlap with the surviving PDSCH. . That is, among the SPS PDSCHs in which resources in the time domain partially or entirely overlap with the surviving PDSCH, only the SPS PDSCH associated with the HARQ process in which the HARQ-ACK feedback is activated is not excluded from the SPS PDSCH set (Q), and is selected in the next selection process It can be. Then, j=j+1 may be set. At this time, the terminal may determine whether the SPS PDSCH set (Q) is empty or j is equal to the number of unicast PDSCHs decodable in one slot. (S1790)

As another example, a case where the UE determines that at least one SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is activated does not exist in the SPS PDSCH set (Q) (S1720) may be considered. That is, it may be considered that only at least one SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is disabled exists in the SPS PDSCH set (Q). At this time, the UE may check at least one SPS PDSCH associated with an HARQ process in which HARQ-ACK feedback is disabled among the SPS PDSCHs in the SPS PDSCH set (Q) (S1760). Thereafter, the UE may select an SPS PDSCH associated with the HARQ process having the lowest HARQ process ID (or HARQ process index) among at least one SPS PDSCH associated with the HARQ process in which HARQ-ACK feedback is disabled as the surviving PDSCH. (S1770) After that, the UE may exclude an SPS PDSCH whose resources in the time domain partially or entirely overlap with the surviving PDSCH from the SPS PDSCH set (Q). (S1780) That is, the UE selects from the SPS PDSCH set (Q) SPS PDSCHs associated with an HARQ process in which HARQ-ACK feedback is activated may be selected with priority, as described above.

Then, when the SPS PDSCH set (Q) is empty or when j is equal to the number of unicast PDSCHs decodable in one slot, the UE can decode the selected SPS PDSCHs. On the other hand, if the SPS PDSCH set (Q) is not empty or if j is not equal to the number of unicast PDSCHs decodable in one slot, the UE checks the SPS PDSCHs in the SPS PDSCH set (Q) and repeats the above-described operation can do.

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

Referring to FIG. 18 , a first device 1800 and a second device 1850 may communicate with each other. In this case, for example, the first device 1800 may be a base station device, and the second device 1850 may be a terminal device. As another example, both the first device 1800 and the second device 1850 may be terminal devices. That is, the first device 1800 and the second device 1850 may be devices that perform mutual communication based on sidelink communication.

As an example, a case in which the first device 1800 is a base station device and the second device 1850 is a terminal device may be considered. In this case, the base station device 1800 may include a processor 1820, an antenna unit 1812, a transceiver 1814, and a memory 1816. The processor 1820 performs baseband-related signal processing and may include an upper layer processing unit 1830 and a physical layer processing unit 1840. The upper layer processing unit 1830 may process operations of a Medium Access Control (MAC) layer, a Radio Resource Control (RRC) layer, or higher layers. The physical layer processing unit 1840 may process physical (PHY) layer operations (eg, uplink reception signal processing and downlink transmission signal processing). In addition to performing baseband-related signal processing, the processor 1820 may control overall operations of the base station apparatus 1800. The antenna unit 1812 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 1816 may store information processed by the processor 1820, software related to the operation of the base station device 1800, an operating system, an application, and the like, and may include components such as a buffer. The processor 1820 of the base station device 1800 may be configured to implement the operation of the base station in the embodiments described in the present invention.

The terminal device 1850 may include a processor 1870, an antenna unit 1862, a transceiver 1864, and a memory 1866. For example, in the present invention, the terminal device 1850 may communicate with the base station device 1800. As another example, in the present invention, a terminal device 1850 may perform sidelink communication with another terminal device. That is, the terminal device 1850 of the present invention refers to a device capable of communicating with at least one of the base station device 1800 and other terminal devices, and is not limited to communication with a specific device. The processor 1870 performs baseband-related signal processing and may include an upper layer processing unit 1880 and a physical layer processing unit 1890. The upper layer processing unit 1880 may process operations of a MAC layer, an RRC layer, or higher layers. The physical layer processing unit 1890 may process PHY layer operations (eg, downlink received signal processing, uplink transmission signal processing, and sidelink signal processing). In addition to performing baseband-related signal processing, the processor 1870 may also control overall operations of the terminal device 1850. The antenna unit 1862 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 1866 may store information processed by the processor 1870, software related to the operation of the terminal device 1850, an operating system, an application, and the like, and may include components such as a buffer. The terminal device 1850 according to an example of the present invention may be associated with a vehicle. For example, the terminal device 1850 may be integrated into a vehicle, located in a vehicle, or located on a vehicle. Also, the terminal device 1850 according to the present invention may be a vehicle itself. In addition, the terminal device 1850 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 1850 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 performance, 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 1850 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 1850 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 1850 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.

Base Station: 1800 Processor: 1820
Upper layer processing unit: 1830 Physical layer processing unit: 1840
Antenna: 1812 Transceiver: 1814
Memory: 1816 Terminal: 1850
Processor: 1870 Upper layer processing unit: 1880
Physical layer processing unit: 1890 Antenna unit: 1862
Transceiver: 1864 Memory: 1866

Claims (1)

In a method for a terminal to perform data decoding based on a non-terrestrial network (NTN) in a wireless communication system,
Checking an SPS PDSCH set (Q) including a plurality of semi-persistent scheduling (SPS) PDSCHs for one serving cell in one slot;
Checking information on whether HARQ-ACK feedback is set for each of the plurality of SPS PDSCHs in an SPS PDSCH set (Q); and
Selecting at least one SPS PDSCH to perform decoding among the plurality of SPS PDSCHs; including, data decoding method.

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