KR20200066167A - Method and apparatus for signal configuration of mobile base station - Google Patents

Abstract

According to the present invention, a timing adjustment method with a non-terrestrial base station (e.g. satellite base station) performed in a terminal may comprise the steps of: receiving a reference time delay value from a satellite base station; receiving a timing advance command from the satellite base station; and calculating an actual time delay value between the terminal and the satellite base station by using the reference time delay value and an index included in the timing advance command, and updating a timing advance value of the terminal with respect to the satellite base station using the calculated actual time delay value. Accordingly, despite the position change of the non-terrestrial base station (e.g. satellite base station), it is possible to stably maintain the connection state between the non-terrestrial base station and the terminal.

Description

Method and apparatus for signal configuration of mobile base station

The present invention relates to a method and apparatus for configuring a signal of a mobile base station, and more particularly, to a timing adjustment method and a beam management method for a mobile base station and an apparatus therefor.

There is a need to develop a mobile satellite communication technology in preparation for communication disruption that can occur in the areas of cellular networks such as mountainous areas, desert areas, island areas, and oceans, and in areas of terrestrial network collapse due to various disasters such as earthquakes, tsunamis, and wars. The satellite communication network is maintained even when the terrestrial network collapses due to disasters and disasters, so the areas where disasters and disasters have occurred are connected to the outside without disconnection, enabling the survival and safety of individuals.

In addition, the need for mobile satellite communication technology is increasing for the construction of a super-connected society that provides mobile communication services even in areas where communication has not been possible in the past, such as mountains and remote areas without communication infrastructure.

In the 3rd generation partnership project (3GPP), a non-terrestrial base station (eg, a base station using a satellite base station or an airborne platform such as an airship) based on 5G new radio (NR) technology is used. Standardization of non-terrestrial networks (NTNs) is in progress. On the other hand, when the non-ground base station is a satellite base station, the distance between the satellite base station and the terminal may be a long distance, and the position of the satellite base station may be continuously changed. Accordingly, there is a need for a method of timing adjustment and beam management between a mobile base station and a terminal, which enables to maintain a connection state between a satellite base station and a terminal.

An object of the present invention for solving the above problems is to provide a timing adjustment and beam management method for a mobile base station.

Another object of the present invention for solving the above problems is to provide a timing adjustment and beam management apparatus for a mobile base station.

An embodiment of the present invention for achieving the above object is a handover method for a satellite base station performed in a terminal, comprising: selecting at least one candidate satellite base station; Performing signal strength measurement on a first candidate satellite base station among the at least one candidate satellite base stations; Selecting the first candidate satellite base station as a target satellite base station if it is determined that the first candidate satellite base station is available as a result of the signal strength measurement; And when it is determined that the first candidate satellite base station is not available as a result of the signal strength measurement, performing signal strength measurement for the second rear satellite base station among at least one candidate satellite base station.

The at least one candidate satellite base stations may be determined as satellite base stations whose elevation for the terminal is greater than or equal to a predetermined threshold.

The elevation angle may be calculated based on ephemeris information of the at least one candidate satellite base station.

The at least one candidate satellite base stations may be determined as satellite base stations whose elevation for the terminal is maintained above a predetermined threshold for a predetermined duration.

The predetermined duration may be set based on the moving speed of the corresponding candidate satellite base station.

The at least one candidate satellite base stations may be determined as satellite base stations that provide the terminal with coverage greater than that of the terminal's current serving satellite base station.

Another embodiment of the present invention for achieving the other object is a timing adjustment method with a satellite base station performed in a terminal, comprising: receiving a reference time delay value from the satellite base station; Receiving a timing advance command from the satellite base station; And an actual time delay value between the terminal and the satellite base station using the reference time delay value and a value included in the timing advance command, and using the calculated actual time delay value, the terminal for the satellite base station. Updating the timing advance value of, the value included in the timing advance command for initial connection or timing advance maintenance, handover, beam switching may have a positive or negative value according to the reference time delay value Can be.

The reference time delay value may be a representative time delay value between the satellite base station and the terminal corresponding to a specific time point, a specific time period, or a specific location of the satellite base station.

The reference time delay value may be received from at least one of PDCCH, RRC signaling, and MAC CE from the satellite base station.

The reference time delay value may be received by being included in the ephemeris of the satellite base station from the satellite base station.

When a new time delay value that replaces the reference time delay value is received in slot n (n is an integer greater than or equal to 0), the terminal receives the new time delay value from the start of slot n+k+1 to the terminal and the satellite. It can be used to calculate the actual time delay value between base stations.

로 정의되며,

는 추가적인(additional) PDSCH(physical downlink shared channel) DM-RS(demodulation reference signal)가 구성될 때 단말의 처리 능력에 대한 PDSCH 수신 시간에 대응하는

심볼들의 시간 길이이며,

는 단말의 처리 능력에 대한 PUSCH(physical uplink shared channel) 준비(preparation) 시간에 대응하는

심볼들의 시간 길이이며,

는 상기 위성 기지국의 셀 내에서의 최대 시간 지연이며,

는 서브 프레임 당 슬롯 수이며,

는 1 msec의 서브 프레임 시간 길이일 수 있다.K is

Is defined as,

Is corresponding to the PDSCH reception time for the processing capability of the terminal when an additional (additional) physical downlink shared channel (PDSCH) demodulation reference signal (DM-RS) is configured

Time length of symbols,

Corresponds to a PUSCH (physical uplink shared channel) preparation time for the processing capability of the terminal

Time length of symbols,

Is the maximum time delay within the cell of the satellite base station,

Is the number of slots per subframe,

May be a subframe time length of 1 msec.

The reference time delay value may be set as a maximum time delay between the satellite base station and the terminal, a minimum time delay between the satellite base station and the terminal, or a time delay between the center of the cell and the satellite base station.

Another embodiment of the present invention for achieving the other object is a method for receiving signals from the first satellite base station and the second satellite base station, which is performed in the terminal, the first BWP of the first satellite base station serving as a base station ( obtaining information about a bandwidth part) and information about a second BWP of the second satellite base station; Providing information about the current location of the terminal to the first satellite base station; Obtaining an estimated time delay value between the terminal and the second satellite base station from the first satellite base station; And estimating a time point when the signal of the second satellite base station arrives at the terminal based on the estimated time delay value, and monitoring the second BWP during an interval within a predetermined time range value from the estimated time point. Including a step, the first satellite base station and the second satellite base station can transmit a signal at the same time.

The information on the first BWP and the information on the second BWP is received from at least one of PDCCH, MAC CE, and RRC signaling from one of the first satellite base station and the second satellite base station, or the Each of the first satellite base station and the second satellite base station may be received through at least one of PDCCH, MAC CE, and RRC signaling.

Information about the first BWP may be received from the first satellite base station as ephemeris of the first satellite base station, and information about a second BWP from the second satellite base station may be received as ephemeris of the second satellite base station. .

A guard band may be set between the first BWP and the second BWP.

Each of the first BWP and the second BWP may be configured to be periodic, semi-persistently, or semi-periodically.

The obtaining of the estimated time delay value may include receiving a difference value between the reference time delay value of the first satellite base station and the estimated time delay value from the first satellite base station; And calculating the estimated time delay value using the difference between the reference time delay value and the estimated time delay value and the reference time delay value.

The reference time delay value may be a representative time delay value between the first satellite base station and the terminal corresponding to a specific time point, a specific time period, or a specific location of the first satellite base station.

When the timing adjustment method and the beam management method according to the embodiments of the present invention are used, the connection state between the non-ground base station and the terminal can be stably maintained despite the position change of the non-ground base station (eg, a satellite base station).

1 is a view for explaining a ServingCellConfigCommonSIB information element (IE) of a 3GPP NR system.
2 is a view for explaining the ssb-PositionsInBurst parameter in the ServingCellConfigCommon IE of the 3GPP NR system.
3 is a diagram for explaining TCI-Sate and QCL-Info parameters of a 3GPP NR system.
4 is a conceptual diagram for explaining a beam setting according to time of a satellite base station to which embodiments of the present invention are applied.
5 is a conceptual diagram illustrating a situation in which signals are received from multiple satellite base stations to which embodiments of the present invention are applied.
6 is a conceptual diagram illustrating a situation in which a beam setting is changed according to the movement of a satellite base station to which the embodiments of the present invention are applied.
7 is a conceptual diagram illustrating a situation in which handover occurs between satellite base stations to which embodiments of the present invention are applied.
8 is a block diagram illustrating a configuration of an apparatus for performing a timing adjustment method and a beam management method according to embodiments of the present invention.

The present invention can be applied to various changes and can have various embodiments, and specific embodiments will be illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. In describing each drawing, similar reference numerals are used for similar components.

Terms such as first, second, A, and B may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from other components. For example, the first component may be referred to as a second component without departing from the scope of the present invention, and similarly, the second component may be referred to as a first component. The term and/or includes a combination of a plurality of related described items or any one of a plurality of related described items.

When an element is said to be "connected" or "connected" to another component, it is understood that other components may be directly connected to or connected to the other component, but there may be other components in between. It should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that no other component exists in the middle.

The terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, terms such as “include” or “have” are intended to indicate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, one or more other features. It should be understood that the existence or addition possibilities of fields or numbers, steps, operations, components, parts or combinations thereof are not excluded in advance.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person skilled in the art to which the present invention pertains. Terms, such as those defined in a commonly used dictionary, should be interpreted as having meanings consistent with meanings in the context of related technologies, and should not be interpreted as ideal or excessively formal meanings unless explicitly defined in the present application. Does not.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In order to facilitate the overall understanding in describing the present invention, the same reference numerals are used for the same components in the drawings, and duplicate descriptions for the same components are omitted.

Embodiments according to the present invention provide a timing adjustment method and a beam management method suitable for a mobile base station of a non-terrestrial network (NTN) by improving a conventional 3GPP new radio (NR) mobile communication system. In the following, reference is made to the following prior documents defining the operation of the 3GPP NR mobile communication system.

Literature 1: 3GPP TS 38.211 V15.3.0, "3rd Generation Partnership Project; Technical Specification Group Radio Access Network; NR; Physical channels and modulation (Release 15)"

Literature 2: 3GPP TS 38.212 V15.3.0, "3rd Generation Partnership Project; Technical Specification Group Radio Access Network; NR; Multiplexing and channel coding (Release 15)"

Prior Document 3: 3GPP TS 38.213 V15.3.0, "3rd Generation Partnership Project; Technical Specification Group Radio Access Network; NR; Physical layer procedures for data (Release 15)"

Literature 4: 3GPP TS 38.214 V15.3.0, "3rd Generation Partnership Project; Technical Specification Group Radio Access Network; NR; Physical layer procedures for data (Release 15)"

Prior Art 5: 3GPP TS 38.321 V15.3.0, "3rd Generation Partnership Project; Technical Specification Group Radio Access Network; NR; Medium Access Control (MAC) protocol specification (Release 15)"

Literature 6: 3GPP TS 38.331 V15.3.0, "3rd Generation Partnership Project; Technical Specification Group Radio Access Network; NR; Radio Resource Control (RRC) protocol specification (Release 15)"

Literature 7: 3GPP TS 38.133 V15.3.0, "3rd Generation Partnership Project; Technical Specification Group Radio Access Network; NR; Requirements for support of radio resource management (Release 15)"

Hereinafter, for convenience of description,'satellite base station' is used as a term representing a non-terrestrial base station or a mobile base station. However, the methods and apparatuses described below can be applied not only to a satellite base station, but also to a base station using an airborne platform, such as an airship.

Timing adjustment method of NR system

According to Section 4.2 of Prior Document 3, timing adjustment of the 3GPP NR system may be set as follows.

을 제공받을 수 있다. 단말이 서빙 셀에 대해 상위 계층 파라미터 n-TimingAdvanceOffset을 제공받지 못하면, 단말은 선행문헌7의 7.1.2 절에 따라 서빙 셀에 대한 타이밍 어드밴스 오프셋의 디폴트 값

을 결정한다. The UE performs a timing advance offset value for the serving cell by the upper layer parameter n-TimingAdvanceOffset for the serving cell.

Can be provided. If the UE does not receive the upper layer parameter n-TimingAdvanceOffset for the serving cell, the UE defaults to the timing advance offset for the serving cell according to Section 7.1.2 of Prior Art 7

Decide.

값에 기초하여 TAG 내의 모든 서빙 셀들에서의 PUSCH/SRS(sounding reference signal)/PUCCH 전송에 대한 상향링크 전송 타이밍을 조정한다. When two component carriers are configured for the serving cell in the UE, the same timing advance offset value is commonly applied to both carriers. When the terminal receives a timing advance command (timing advance command) or a timing adjustment instruction (timing adjustment indication) for a timing advance group (TAG), the terminal

The uplink transmission timing for PUSCH/SRS (sounding reference signal)/PUCCH transmission in all serving cells in the TAG is adjusted based on the value.

를 나타낸다.

의 부반송파 간격에 대해, TAG에 대한 타이밍 어드밴스 명령은 TAG의 현재 상향링크 타이밍에 대한 상향링크 타이밍의 변화를

의 배수로 나타낸다.The timing adjustment instruction in the prior document 5 is the initial time alignment value used in the TAG.

Indicates.

For the subcarrier spacing of, the timing advance command for the TAG changes the uplink timing for the current uplink timing of the TAG.

It is expressed in multiples of.

는 0, 1, 2, ?, 3846의 인덱스 값으로

를 지시하게 된다. 여기서,

의 부반송파 간격의 경우, TAG에 대한 시간 조정의 양은

이다.

는 선행문헌 1에 정의되어 있으며 단말이 랜덤 액세스 응답을 수신한 후 첫 번째로 수행하는 상향링크 전송의 부반송파 간격과 관련이 있다. In the case of a random access response, in the timing advance command for the TAG (Section 6.2.3 of Prior Document 5),

Is the index value of 0, 1, 2, ?, 3846

Will be instructed. here,

For subcarrier spacing of, the amount of time adjustment for TAG is

to be.

Is defined in the prior document 1 and is related to the subcarrier interval of uplink transmission performed first after the UE receives the random access response.

는 현재

의 값(

)을 새로운

의 값(

)으로 조정하는 것을 지시한다. 이 경우,

는 0, 1, 2, ?, 63의 인덱스 값이며,

의 부반송파 간격에 대해,

가 정의된다. 양 또는 음의 값에 의한

값의 조정은 TAG에 대한 상향링크 전송 타이밍을 대응하는 양만큼 각각 전진 또는 지연시키는 것을 나타낸다. In other cases except for the random access response, in the timing advance command for the TAG (Section 6.1.3.4 of precedent document 5),

Is currently

The value of

New)

The value of

). in this case,

Is an index value of 0, 1, 2, ?, 63,

About the subcarrier spacing of,

Is defined. Positive or negative

Adjustment of the value indicates that the uplink transmission timing for the TAG is advanced or delayed by a corresponding amount, respectively.

로 정의된다. 여기서,

는 추가적인(additional) PDSCH DM-RS가 구성될 때 단말의 처리 능력(UE processing capability 1)에 대한 PDSCH 수신 시간에 대응하는

심볼들의 시간 길이(time duration)이며,

는 단말의 처리 능력(UE processing capability 1)에 대한 PUSCH 준비(preparation) 시간에 대응하는

심볼들의 시간 길이이며,

는 12 비트의 타이밍 어드밴스 명령 필드에 의해 제공될 수 있는 최대 타이밍 어드밴스 값이며,

는 서브 프레임 당 슬롯 수이며,

는 1 msec의 서브 프레임 시간 길이이다.For the timing advance command received in the uplink slot n, the adjustment of the uplink transmission timing is applied from the start of the slot (n+k+1), k is

Is defined as here,

Corresponds to a PDSCH reception time for UE processing capability 1 when an additional PDSCH DM-RS is configured.

The time duration of symbols,

Corresponds to a PUSCH preparation time for UE processing capability 1

Time length of symbols,

Is the maximum timing advance value that can be provided by the 12-bit timing advance command field,

Is the number of slots per subframe,

Is a subframe time length of 1 msec.

과

는 TAG 내의 모든 상향링크 캐리어에 대한 모든 구성된 상향링크 대역폭 부분(BWP(bandwidth part))들 및 그들에 대응하여 구성된 하향링크 BWP들의 부반송파 간격들 중에 최소 부반송파 간격에 대해 결정된다. 슬롯 n 과

은 TAG 내의 모든 상향링크 캐리어에 대한 모든 구성된 상향링크 BWP들의 부반송파 간격 중 최소 부반송파 간격에 의해 결정된다.

는 상위 계층 파라미터 initialuplinkBWP에 의해 제공되는 초기 액티브 상향링크 BWP와 TAG 내의 모든 상향링크 캐리어들에 대한 모든 구성된 상향링크 BWP들의 부반송파 간격들 중 최소 부반송파 간격에 대해 결정된다.

and

Is determined for a minimum subcarrier interval among all configured uplink bandwidth parts (BWPs) for all uplink carriers in the TAG and subcarrier intervals of downlink BWPs configured corresponding to them. Slot n and

Is determined by a minimum subcarrier spacing among subcarrier spacings of all configured uplink BWPs for all uplink carriers in the TAG.

Is determined for the minimum subcarrier spacing among the subcarrier spacings of all configured uplink BWPs for all uplink carriers in the initial active uplink BWP and TAG provided by the upper layer parameter initialuplinkBWP.

Satellite ephemeris

The main parameters of the orbital dynamics of all commercial satellites are publicly available. This information is called ephemeris or ephemeris, and is used by astronomers to describe the position and orbital behavior of stars and other objects.

The ephemeris for each object is expressed in American standard code for information interchange (ASCII) files using the TLE (Two-Line Element) format. The TLE data format encodes a list of orbital elements of an earth's orbital object, such as a satellite, into two 70 column lines. TLE is the de facto standard for this information.

With TLE format data, several models are available that can calculate the position of an object rotating around the Earth as a function of time at earth-centered, earth-fixed (ECEF) Cartesian x, y, and z coordinates. Also, the instantaneous velocity of the object can be obtained at that time. In the ECEF coordinates, the z-axis points to the actual North, and the x-axis and y-axis intersect the latitude and longitude of 0 degrees, respectively. With appropriately selected time information (epoch) for the object, the ephemeris is calculated by the regular intervals, coordinates, x, y, z coordinates, which are composed of easy-to-use tables. The instantaneous position and velocity of the object can be interpolated in the table entry for any time point. If desired, the location of the object can also be converted to latitude, longitude and altitude.

Hereinafter, a handover method of a connected mode terminal using satellite astronomical forces will be described.

If the position of the satellite and the terminal (or earth station) is expressed in ECEF coordinates, an azimuth and elevation that points to the satellite may be determined. This information can be used by the antenna steering mechanism for initial antenna pointing of the new satellite to be used.

Thus, the terminal can generate a list of potential handover candidates at any given time. For example, the list of handover candidates can be generated by searching for the current and next epochs of satellite base stations in the network where the elevation angle from the terminal is above a certain threshold. In addition, the list of handover candidates may include a satellite base station currently in service.

The terminal initiated handover may be triggered when the elevation angle of the serving satellite base station currently serving the terminal changes below a certain threshold. Thereafter, the terminal may select at least one candidate satellite base station from the list of handover candidates. In one embodiment, at least one candidate satellite base station may have a higher elevation angle than the current serving satellite base station. In addition, this elevation must be maintained above the threshold for a predetermined duration to minimize frequent handovers. This duration can be determined by the speed of the candidate satellite base station. In another embodiment, the terminal may select at least one candidate base station having a longer coverage than the current serving satellite base station from the list of handover candidates.

When at least one candidate satellite base station is selected, the terminal may perform signal strength measurement to verify the availability of the selected at least one candidate satellite base station. In this case, the terminal may perform signal strength measurement from a candidate satellite base station having the best elevation angle (or coverage).

If the candidate satellite base station for which signal strength is measured is determined to be available as a result of signal strength measurement, the terminal may finally determine the candidate satellite base station (for handover) as the target satellite base station. As a result of signal strength measurement, if it is determined that the candidate satellite base station for which the signal strength is measured is not available (for example, when the corresponding satellite base station is blocked by terrain or buildings), the signal strength measurement results for other candidate satellite base stations are determined. Based on this, the final target satellite base station can be determined.

On the other hand, if all candidate satellite base stations are not immediately available, the terminal can continue to use the current serving satellite base station while continuing to measure signal strength until an available candidate satellite base station is determined.

Similarly, depending on the positions of available satellite base stations and terminals, beam-to-beam handover in the same satellite base station may be performed based on the beam pattern of the corresponding satellite base station. The terminal may determine a reference direction (boresight) for the satellite base station from the location of the satellite base station indicated by the ECEF coordinates. In consideration of the trajectory of the given satellite base station and the location of the terminal, it may be determined to apply the beam pattern of the candidate beam for serving and handover of the corresponding satellite base station. When the terminal crosses the boundary between the serving beam and the candidate beam, one beam for beam handover may be triggered.

SS/PBCH block configuration of NR system

According to Section 4.1 of Citation 3, the synchronization signal block (SSB (synchronization signal block), hereinafter also referred to as SS/PBCH (synchronization signal/physical broadcast channel) block) of the 3GPP NR system is set as follows.

로부터 하프 프레임내에서의 SS/PBCH 블록 인덱스의 3 MSB 비트를 결정한다. The candidate SS/PBCH blocks in the half frame are indexed in ascending order on the time axis from 0 to L-1. The terminal acquires 2 LSB bits of the corresponding SS/PBCH block index in a half frame when L=4 from a one-to-one mapping with an index of a DM-RS sequence transmitted on a physical broadcast channel (PBCH) of the SS/PBCH block. In the case of L>4, 3 LSB bits of the corresponding SS/PBCH block index in a half frame are determined. When L=64, the UE bit of the PBCH payload as described in Section 4 of Prior Document 2

From 3 MSB bits of the SS/PBCH block index in a half frame are determined.

The UE may be provided for each serving cell by periodicity (periodicity) of half frames for receiving SS/PBCH blocks for the serving cell by the upper layer parameter ssb-periodicityServingCell. If the periodicity of the half frames for reception of SS/PBCH blocks is not configured, the terminal assumes the periodicity of the half frame. The UE assumes that the periodicity is the same for all SS/PBCH blocks in the serving cell.

For SS/PBCH blocks that provide a higher layer parameter MasterInformationBlock (MIB), the terminal may be configured by parameter ssb-PositionsInBurst of SystemInformationBlockType1 (SIB1). ssb-PositionsInBurst is a parameter indicating the indexes of the SS/PBCH block so that the UE does not receive other signals or channels for REs overlapping with REs (resource elements) corresponding to the SS/PBCH block. ssb-PositionsInBurst can also be included in the ServingCellConfigCommon information element for setting cell-specific parameters. The terminal expects the configuration provided by ssb-PositionsInBurst in ServingCellConfigCommon to be the same as the configuration provided by ssb-PositionsInBurst in SystemInformationBlockType1.

1 is a view for explaining a ServingCellConfigCommonSIB information element (IE) of a 3GPP NR system, and FIG. 2 is a view for explaining the ssb-PositionsInBurst parameter in the ServingCellConfigCommon IE of the 3GPP NR system.

In Fig. 1, detailed components of the ServingCellConfigCommonSIB IE described in the prior document 6 are shown. The ssb-PostionsInBurst parameter included in the ServingCellConfigCommonSIB IE of FIG. 1 expresses indexes of SS/PBCH blocks transmitted in a synchronization signal (SS) burst in a hierarchical manner of inOneGroup and groupPresence, each represented by 8 bits. Here, inOneGroup classifies the group and groupPresence classifies the SSB within the group.

In FIG. 2, the ssb-PostionsInBurst parameter of ServingCellConfigCommon IE described in Prior Art 6 may include bitmaps indicating the time domain location of SS/PBCH blocks transmitted in the SS burst. For example, the first (ie, leftmost) bit of each bitmap corresponds to SS/PBCH block index 0, and the second bit of each bitmap corresponds to SS/PBCH block index 1. In the bit map, a value of 0 indicates that the corresponding SS/PBCH block is not transmitted, and a value of 1 indicates that the corresponding SS/PBCH block is transmitted.

Meanwhile, according to Section 5.1.5 of Prior Art 4, the antenna port QCL may be set as follows.

부터 적용된다. The UE uses an activation command used to map up to 8 TCI states to code points in the DCI field'Transmission Configuration Indication' (refer to Section 6.1.3.14 of Prior Document 5). To receive. When the HARQ-ACK corresponding to the PDSCH carrying the activation command is transmitted in slot n, the indicated mapping between the code points of the DCI field'transmission configuration indication' and TCI states is a slot

It applies from.

3 is a diagram for explaining TCI-Sate and QCL-Info parameters of a 3GPP NR system.

Before the UE receives the upper layer configuration of the TCI states and the activation command is received, the UE receives the SS/PBCH block and the'QCL-TypeA' and'QCL-TypeD' whose DM-RS ports of the PDSCH of the serving cell are determined in the initial access. It can be assumed to have a QCL relationship to (if applicable).

Timing Adjustment Method for Satellite Base Station

Hereinafter, a time synchronization setting method for a satellite base station and a time synchronization setting method for a plurality of satellite base stations will be described as a time synchronization setting method for a satellite base station according to an embodiment of the present invention.

(One) Timing adjustment method for one satellite base station

A satellite base station is a mobile base station whose position changes with time, and may be a transparent base station or a re-generative base station. In embodiments of the present invention, the satellite base station may be assumed to be a low earth orbit (LEO), a medium earth orbit (MEO), or a geostationary equatorial orbit (GEO).

4 is a conceptual diagram for explaining a beam setting according to time of a satellite base station to which embodiments of the present invention are applied.

4, a mobile satellite base station 410 is shown. T1 to T4 denote specific time points (or time periods), and D1,1, D1,2, and D2 to D4 denote time delays according to the distance between the satellite base station 410 and the cell. Here, D1,1 is the time delay from the center of the cell to the satellite base station 410, and D1,2 is the minimum time delay from the cell to the satellite base station 410. For example, the time delay between the cell and the satellite base station may be set based on the cell center, or may be set to a minimum time delay or a maximum time delay or a specific time delay defined by the base station. Hereinafter, for convenience, the time delay at the time point T1 will be described as the representative value D1 instead of D1,1 or D1,2 (that is, D2 to D4 are also representative values of the time delay at the time points T2 to T4, respectively). ). D1 to D4 may be different depending on the movement of the satellite base station. Hereinafter, D1 to D4 are referred to as'reference time delay values' at specific time points (or time intervals) corresponding to each or specific locations of the satellite base station.

값을 획득하고,

값은

에서

로 타이밍 어드밴스 명령에 의해서 지속적으로 업데이트될 수 있다. 한편, 단말은 위성 기지국으로부터 현재 시점(또는, 현재 위치)에서의 기준 시간 지연값(Di(i=1~N, 도 4에서 N=4)을 미리 수신할 수 있다. 일 실시예에서, Di(i=1~N) 값은 RRC 파라미터, MAC CE 파라미터, DCI 파라미터 또는 이들의 조합으로 상기 위성 기지국(410)으로부터 단말에 전송될 수 있다. 다른 실시예에서, Di(i=1~N) 값은 위성 기지국의 좌표와 각도를 나타내는 천문력에 포함되어 상기 위성 기지국으로부터 수신될 수 있다.The UE receives a random access response for PRACH transmission during initial access.

Get the value,

The value is

in

It can be continuously updated by the timing advance command. Meanwhile, the terminal may previously receive a reference time delay value (Di(i=1 to N, N=4 in FIG. 4)) at a current time point (or a current position) from a satellite base station. The value of (i=1~N) may be transmitted to the terminal from the satellite base station 410 through an RRC parameter, a MAC CE parameter, a DCI parameter, or a combination thereof.In another embodiment, Di(i=1~N) The value is included in the astronomical force representing the coordinates and angles of the satellite base station and can be received from the satellite base station.

The satellite base station can express the timing advance value based on Di. That is, on the assumption that the terminal already knows Di, the satellite base station can express the timing advance value as the difference between Di and the actual time delay.

에서 타이밍 어드밴스 값

가 Di와 실제 시간 지연과의 차이를 나타낼 수 있다. 이 경우

는 Di에 따라 양 또는 음의 값을 표현할 수 있다. 이는 Di의 정의에 따라 음의 값이 표현될 수도 있기 때문이다. 즉, 위성 기지국과 단말의 거리에 따른 실제 시간 지연이 T_d일 경우

는 (T_d-Di) 또는 (Di-T_d)로 표현될 수 있다. 마찬가지로, 전술된

에서도

가 Di와 실제 시간 지연과의 차이를 나타낼 수 있다.First, the aforementioned

Timing advance value

Can represent the difference between Di and the actual time delay. in this case

Can represent a positive or negative value depending on Di. This is because a negative value may be expressed according to the definition of Di. That is, when the actual time delay according to the distance between the satellite base station and the terminal is T_d

Can be expressed as (T_d-Di) or (Di-T_d). Likewise, the aforementioned

Edo

Can represent the difference between Di and the actual time delay.

또는

를 인식할 수 있다. 이를 방지하기 위해, 위성 기지국은 Di(i=2)에 대한 정보를 단말에게 전송한 슬롯 n 이후의 슬롯 n+k+1부터 Di(i=2)에 따른

또는

를 적용할 수 있다. 슬롯 n+k까지는 단말은 Di(i=1)에 따른

또는

가 적용되는 것으로 인식할 수 있다. 여기서 k는

로 정의되며,

는 상기 위성 기지국의 셀에서의 최대 시간 지연으로 Di+alpha로 표현될 수 있다. 여기서, alpha는 셀과 위성 기지국의 기준 시간 지연값 Di이 어떻게 설정되는지에 따라서 달라질 수 있다. 예를 들어, Di가 셀과의 최대 시간 지연으로 설정될 경우 alpha는 0이 될 수 있다.

를 제외한 나머지 파라미터들 앞서 설명된 3GPP NR 시스템의 타이밍 조절 방법에서 이용되는 파라미터들과 동일하다. On the other hand, even in a situation where Di is updated (for example, a reference time delay value is changed from D1 to D2), the terminal is configured according to previous Di(i=1)

or

Can recognize. To prevent this, the satellite base station according to Di(i=2) from slot n+k+1 after slot n that transmits information on Di(i=2) to the terminal.

or

Can be applied. Up to slot n+k, the terminal is according to Di(i=1)

or

Can be recognized as applied. Where k is

Is defined as,

Can be expressed as Di+alpha as the maximum time delay in the cell of the satellite base station. Here, alpha may vary according to how the reference time delay value Di of the cell and the satellite base station is set. For example, if Di is set as the maximum time delay with the cell, alpha may be 0.

Other parameters except are the same as those used in the timing adjustment method of the 3GPP NR system described above.

(2) Timing adjustment method for multiple satellite base stations

One terminal can receive signals from multiple satellite base stations at the same time. This may be used in a handover procedure in which a terminal located in a cell changes a serving satellite base station. Multiple satellite base stations can use different frequency bands to transmit signals to the same cell at the same time. Alternatively, multiple satellite base stations may use different beams or use different BWPs to transmit signals to the same cell at the same time. As described above, a method of allowing signals to be received by a terminal when a plurality of satellite base stations transmit signals using different frequency bands, different beams, or different BWPs is described.

5 is a conceptual diagram illustrating a situation in which signals are received from multiple satellite base stations to which embodiments of the present invention are applied.

Referring to FIG. 5, one terminal 501 may receive signals from two satellite base stations 510 and 520 at the same time. At this time, in order for the satellite base station 510 and the satellite base station 520 to use different BWPs, information on the BWP configuration of the satellite base station 510 and the satellite base station 520 may have to be transmitted to the terminal 501. have.

In one embodiment, the configuration for the BWP (for example, the satellite base station 510 is BWP1, the satellite base station 520 is BWP2) through which a measurement signal (SS/PBCH block or CSI-RS) for each base station is transmitted. Information may be transmitted to the UE in RRC parameters, MAC CE parameters, DCI parameters, or a combination thereof. In this case, the information on the BWP1 and BWP2 may be received from one of the satellite base station 510 and the satellite base station 520, or may be received independently from each satellite base station. For example, the satellite base station 510 and the satellite base station 520 exchange BWP configuration information through an inter-satellite link (ISL), and one of the satellite base stations transmits the BWP configuration information of the other satellite base station to its BWP. It can be provided to the terminal together with the configuration information. Alternatively, the satellite base station 510 may provide information on the BWP1 to the terminal, and the satellite base station 520 may provide information on the BWP to the terminal.

In another embodiment, the information may be transmitted by being included in astronomical forces representing coordinates and angles of each satellite base station. When two satellite base stations transmit signals in the set BWPs at the same time, since the time delay between the terminal and each satellite base station is different, interference between the BWPs may occur at the terminal receiving end. To prevent this, when configuring BWPs, a guard band may be set between BWPs.

Meanwhile, a serving base station (eg, satellite base station 510) currently providing a service to the terminal 501 may be provided with information about the location of the terminal from the terminal 501. In this case, since the corresponding serving base station (eg, satellite base station 510) knows the location of the terminal and a different satellite base station (eg, satellite base station 520), the other satellite base station (eg, satellite base station 520) The time delay TA2 according to the distance between the terminal 501 and the terminal 501 may be calculated. The serving base station (eg, the satellite base station 510) may transmit information on the BWPs of the satellite base station 510 and the satellite base station 520 and TA2 information to the terminal. In this case, the serving base station (eg, satellite base station 510) configures the information of TA2 as a difference value from the reference time delay value Di (i=4) for the above-described serving base station (eg, satellite base station 510). It can also be transmitted to the terminal. The terminal may calculate the time that the signal of the satellite base station (eg, the satellite base station 520) arrives from TA2 on the assumption that the two satellite base stations 510 and 520 transmit the signal at the same time.

Meanwhile, the BWP for signal measurement described above may be configured in the serving base station 510 and the satellite base station 520 based on the triggering of the terminal. For example, assuming a handover situation, when the serving base station 510 and the satellite base station 520 exist at a specific location (ie, when the satellite base station 520 becomes a candidate base station), the terminal is configured to measure the above-described signals. You can trigger the configuration of the BWP.

Alternatively, the BWP for signal measurement described above may be configured by a satellite base station 510 or 520. For example, the satellite base station 510 or 520 may configure the BWP for the signal measurement periodically, semi-persistently, or semi-periodically.

Since the arrival time of the SS/PBCH block for the BWP1 of the satellite base station 510 and the arrival time of the SS/PBCH block for the BWP2 of the satellite base station 520 are different, the terminal (the estimated satellite base station 520 signal is The BWP2 of the satellite base station 520 may be monitored during the time of arrival ± a predetermined time range value (P_GT)). The satellite base station 520 may also maintain the configuration of the BWP for signal measurement during the period of P_D with a period of P_B. Here, P_D is associated with P_GT, and P_B and P_D may be provided to the terminal by the satellite base station 520 as an RRC parameter.

On the other hand, when the satellite base station 520 transmits the CSI-RS periodically, semi-permanently, or semi-periodically for measurement, the transmitted CSI-RS is not cell-specific, but UE-specific. Or, if the group-specific (group-specific) CSI-RS, the satellite base station 520 may transmit the transmission of the CSI-RS according to the time that the terminal (or group) receives the signal transmitted by the satellite base station 510. have. That is, the satellite base station 520 transmits the CSI-RS at a time earlier or slower than the transmission time of the satellite base station 510, so that the time at which the transmitted CSI-RS is received at the terminal (or group) is the satellite base station 510. ) Can be matched with the time that the signal transmitted from the terminal (or group) is received.

이다. 위성 기지국(520)는 전송 시간을 조정하기 위해 위성 기지국(510)으로부터 해당 정보를 ISL(inter-satellite link)를 통해 획득할 수도 있다. In this case, when the value of TA2 is the same as TA1, the terminal recognizes that the signal of the satellite base station BS2 is the same as the signal of the satellite base station BS1. Here, TA1 is described in "(1) Time Synchronization Setting Method for One Satellite Base Station"

to be. The satellite base station 520 may obtain corresponding information from the satellite base station 510 through an inter-satellite link (ISL) to adjust the transmission time.

The above-described methods are applicable when transmitting signals for data as well as signals for measurement.

Beam management method of satellite base station

6 is a conceptual diagram illustrating a situation in which a beam setting is changed according to the movement of a satellite base station to which the embodiments of the present invention are applied.

Referring to FIG. 6, it is assumed that the satellite base station 610 moves to the terminal 601 existing in the cell C1 while providing the service. The satellite base station 610 moves according to the passage of time (times T1 to T4), and may set beams L1 to L4 at the times T1 to T4. For example, beam L1 may be set at time T1, beam L2 may be set at time T2, beam L3 may be set at time T3, and beam L4 may be set at time T4.

On the other hand, beams L1,1 to L1,3 are narrow beams that can be set in beam L1. In this case, L1 and L1,1 to L1,3 may be respectively expressed as a longbitmap of the ssb-PositionsInBurst parameter described through FIG. 2 or a hierarchical manner.

The beams L1 to L4 that are not the narrow beams L1, 1 to L1, 3 are beams classified by time T1 to T4 according to the movement of the satellite base station to maintain the cell. On the side of the satellite base station 610, the beams L1 to L4 may be the same single beam, and L (number of beams) may be set to 1. That is, the satellite base station 610 and the terminal 601 may not distinguish the beams L1 to L4. However, even when the serving base station is changed (eg, a handover situation), it may be easy to distinguish beams to provide continuous service. To this end, the indexes of the beams L1 to L4 over time (T1 to T4) are mapped to the indexes of the SS/PBCH block, similar to the beam sweeping method of the ground base station (gNB) of the general NR system. It is possible to distinguish the beams L1 to L4 according to the time T1 to T4.

In this case, the SS/PBCH block transmitted by time can be distinguished by using the ssb-PositionInBurst parameter. For example, as shown in FIG. 4, when the beams are divided according to four times (T1 to T4), the shortBitmap of the ssb-PositionInBurst parameter is L1={1,0,0,0} to L4={0, 0,0,1}.

Alternatively, the beam can be distinguished only in two or three cases. As one example, L1={1,0,0,0} and {L2, L3, L4}={0,1,0,0} distinguish between two cases (service start time and remaining time of the cell) can do. As another example, three cases (L1={1,0,0,0}, {L2, L3}={0,1,0,0} and L4={0,0,1,0}) Service start time, cell service last time, and rest time).

Meanwhile, in a handover situation, the serving base station may transmit QCL information of a candidate (neighbor) base station to the terminal by utilizing the information.

7 is a conceptual diagram illustrating a situation in which handover occurs between satellite base stations to which embodiments of the present invention are applied.

For example, as shown in FIG. 7, when the beam L1 for the satellite base station 710 is mapped to the SS/PBCH block index 1, the information about the beam L4 of the satellite base station 720, the satellite base station 710 ) Can be transmitted to the terminal 711 through the TCI with the SS/PBCH block index 4 obtained through the satellite base station 710. At this time, the premise that the same QCL can be applied between different satellite base stations is utilized. It is possible to set the TCI according to the QCL between satellites or between satellite base stations, and the satellite base station 720 to operate to set the QCL relationship between any satellite (or satellite base station, 710) and another satellite (or satellite base station, 720). The TCI of the satellite base station 710 may be applied to the transmission channel of. When four beam patterns are mapped to SSB indexes 1 to 4, it can be assumed that the patterns of beams of the satellite base station 710 and the patterns of beams of the satellite base station 720 are the same (or similar). This is because satellite base stations move to this same route. Therefore, when the terminal 711 needs to know the beam pattern of the satellite base station 720, the beam pattern is already known by the terminal 711 measured by the SSB index 4 of the satellite base station 710. The satellite base station 710 can inform the terminal 711 that the corresponding beam pattern is the SSB index 4 beam pattern without the terminal 711 having to measure the corresponding beam pattern of the base station 720. Such information may be included in the satellite base station 720 and the TCI ID (TCI of the satellite base station 710), such as RadioLinkMonitoringConfig or HandoverCommand message.

In another embodiment, NZP-CSI-RS-ResourceId can be used instead of the index of the SS/PBCH block. That is, instead of measuring the beam pattern using the SS/PBCH block and mapping it to the index of the SS/PBCH block, the NZP-CSI-RS is measured in the same way and the beam pattern is assigned to the NZP-CSI-RS-Resource ID. Can be mapped. This may be used to set the initial value when receiving a signal from the satellite base station 520 or service provided from the satellite base station 520 described with reference to FIG. 5. For this, QCL-Info may include a unique identifier (ID) of a satellite base station as well as a cell and a bwp-Id. For example, a satellite catalog number of the above-described TLE data format may be used as a unique identifier of the satellite base station.

In addition, a reference RS, SS/PBCH block or CSI-RS should be included in the target RS, not the reference RS. When the reference RS is an SS/PBCH block or a CSI-RS, the QCL for this may be transmitted in RRC parameters, MAC CE parameters, DCI parameters, or a combination thereof. When the QCL is represented by the SS/PBCH block index, each of the QCLs may be expressed using a longbitmap of the ssb-PositionsInBurst parameter, or may be expressed in a hierarchical manner. When QCL is expressed in a hierarchical manner, only inOneGroup can be used for QCL. For some beams (e.g. L1 to L4 or inOneGroup), TCI may be set to cell-specific rather than UE-specific and QCL may be assumed.

The UE may classify the beam by the SS/PBCH block index and inform the QCL through Transmission configuration index (TCI). As described with reference to FIGS. 4 and 5, Di, SS/PBCH block, and BWP configuration information have a dependency on the location of a satellite base station, and this information may be included in astronomical power. The QCL information can be equally applied to downlink as well as uplink by utilizing spatial relation info for terminal transmission.

On the other hand, the parameter (Mv_I) indicating whether the satellite base station is a satellite base station that forms a beam that moves on the ground (motion over earth) or the beam is a satellite base station that forms a ground fixed (earth fixed) beam, the RRC Parameters, MAC CE parameters, DCI parameters, or a combination thereof. The parameter may be included in the astronomical force representing the coordinates and angle of the satellite. Through this, the terminal can recognize a procedure to be performed by the terminal.

For example, if the terminal recognizes that the corresponding base station is a satellite base station that forms a beam moving on the ground through the parameter Mv_I (or, if the Mv_I parameter does not exist), if there is no TCI information, the terminal corresponds to the initial connection Instead of using the beam, the most recently measured beam of the SS/PBCH block is replaced. In the case of uplink, the UE can use a beam having a spatial relation to the most recently measured SS/PBCH block.

Meanwhile, if the terminal recognizes that the corresponding base station is a satellite base station forming a fixed beam on the ground through the parameter Mv_I, the terminal may use a beam corresponding to the initial access.

Apparatus according to an embodiment of the invention

8 is a block diagram illustrating a configuration of an apparatus for performing a timing adjustment method and a beam management method according to embodiments of the present invention.

The device illustrated in FIG. 8 may be a communication node (terminal or base station) for performing the method according to an embodiment of the present invention.

Referring to FIG. 8, the communication node 800 may include at least one processor 810, a memory 820, and a transmission/reception device 830 connected to a network to perform communication. In addition, the communication node 800 may further include an input interface device 840, an output interface device 850, a storage device 860, and the like. Each of the components included in the communication node 800 may be connected by a bus 870 to communicate with each other.

The processor 810 may execute a program command stored in at least one of the memory 820 and the storage device 860. The processor 810 may mean a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods according to embodiments of the present invention are performed. Each of the memory 820 and the storage device 860 may be configured as at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory 820 may be configured with at least one of read only memory (ROM) and random access memory (RAM).

The methods according to the present invention can be implemented in the form of program instructions that can be executed through various computer means and can be recorded in computer readable media. Computer-readable media may include program instructions, data files, data structures, or the like alone or in combination. The program instructions recorded on the computer-readable medium may be specially designed and configured for the present invention or may be known and usable by those skilled in computer software.

Examples of computer-readable media include hardware devices specially configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include high-level language codes that can be executed by a computer using an interpreter, etc., as well as machine language codes such as those produced by a compiler. The above-described hardware device may be configured to operate with at least one software module to perform the operation of the present invention, and vice versa.

Although described with reference to the above embodiments, those skilled in the art understand that various modifications and changes can be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. Will be able to.

Claims (20)

As a handover method for a satellite base station performed in the terminal,
Selecting at least one candidate satellite base station;
Performing signal strength measurement on a first candidate satellite base station among the at least one candidate satellite base stations;
Selecting the first candidate satellite base station as a target satellite base station if it is determined that the first candidate satellite base station is available as a result of the signal strength measurement; And
And as a result of the signal strength measurement, if it is determined that the first candidate satellite base station is not available, performing signal strength measurement for a second candidate satellite base station among at least one candidate satellite base station.
Handover method. The method according to claim 1,
The at least one candidate satellite base stations are determined as satellite base stations whose elevation for the terminal is greater than or equal to a predetermined threshold.
Handover method. The method according to claim 2,
The elevation angle is calculated based on ephemeris information of the at least one candidate satellite base station,
Handover method. The method according to claim 1,
The at least one candidate satellite base stations are determined as satellite base stations whose elevation for the terminal is maintained above a predetermined threshold for a predetermined duration,
Handover method. The method according to claim 4,
The predetermined duration is set based on the moving speed of the corresponding candidate satellite base station,
Handover method. The method according to claim 1,
The at least one candidate satellite base stations are determined as satellite base stations that provide the terminal with coverage greater than that of the terminal's current serving satellite base station,
Handover method. As a timing adjustment method with a satellite base station performed in the terminal,
Receiving a reference time delay value from the satellite base station;
Receiving a timing advance command from the satellite base station; And
The reference time delay value and the value included in the timing advance command are used to calculate an actual time delay value between the terminal and the satellite base station, and using the calculated actual time delay value, the terminal of the terminal to the satellite base station is calculated. And updating the timing advance value.
The value included in the timing advance command for initial connection or timing advance maintenance, handover, and beam switching has a positive or negative value according to the reference time delay value,
How to adjust timing. The method according to claim 7,
The reference time delay value is a representative time delay value between the satellite base station and the terminal corresponding to a specific time point, a specific time period, or a specific location of the satellite base station,
How to adjust timing. The method according to claim 7,
The reference time delay value is received from at least one of PDCCH, RRC signaling, and MAC CE from the satellite base station,
How to adjust timing. The method according to claim 7,
The reference time delay value is received by being included in the ephemeris of the satellite base station from the satellite base station,
How to adjust timing. The method according to claim 7,
When a new time delay value that replaces the reference time delay value is received in slot n (n is an integer greater than or equal to 0), the terminal receives the new time delay value from the start of slot n+k+1 to the terminal and the satellite. Used to calculate the actual time delay value between base stations,
How to adjust timing. The method according to claim 11,
K is

Is defined as,

Is corresponding to the PDSCH reception time for the processing capability of the terminal when an additional (additional) physical downlink shared channel (PDSCH) demodulation reference signal (DM-RS) is configured

Time length of symbols,

Corresponds to a PUSCH (physical uplink shared channel) preparation time for the processing capability of the terminal

Time length of symbols,

Is the maximum time delay within the cell of the satellite base station,

Is the number of slots per subframe,

Is a subframe time length of 1 msec,
How to adjust timing. The method according to claim 8,
The reference time delay value is set to a maximum time delay between the satellite base station and the terminal, a minimum time delay between the satellite base station and the terminal, or a time delay between the center of the cell and the satellite base station,
How to adjust timing. As a method for receiving signals from the first satellite base station and the second satellite base station, which is performed in the terminal,
Obtaining information about a first bandwidth part (BWP) of a first satellite base station serving as a serving base station and information about a second BWP of a second satellite base station;
Providing information about the current location of the terminal to the first satellite base station;
Obtaining an estimated time delay value between the terminal and the second satellite base station from the first satellite base station; And
Estimating a time point when the signal of the second satellite base station arrives at the terminal based on the estimated time delay value, and monitoring the second BWP during an interval within a predetermined time range value from the estimated time point. Including,
The first satellite base station and the second satellite base station transmits a signal at the same time,
How to receive signals. The method according to claim 14,
The information on the first BWP and the information on the second BWP is received from at least one of PDCCH, MAC CE, and RRC signaling from one of the first satellite base station and the second satellite base station, or the Is received by at least one of PDCCH, MAC CE, and RRC signaling by each of the first satellite base station and the second satellite base station,
How to receive signals. The method according to claim 14,
Information about the first BWP is received from the first satellite base station as the astronomical power of the first satellite base station, and information about the second BWP from the second satellite base station is received as the astronomical power of the second satellite base station,
How to receive signals. The method according to claim 14,
A guard band is set between the first BWP and the second BWP,
How to receive signals. The method according to claim 14,
Each of the first BWP and the second BWP is composed of periodic, semi-persistently, or semi-periodically,
How to receive signals. The method according to claim 14,
Acquiring the estimated time delay value is
Receiving a difference value between a reference time delay value of the first satellite base station and the estimated time delay value from the first satellite base station; And
Comprising the step of calculating the estimated time delay value using the difference between the reference time delay value and the estimated time delay value and the reference time delay value,
How to receive signals. The method according to claim 19,
The reference time delay value is a representative time delay value between the first satellite base station and the terminal corresponding to a specific time point, a specific time period, or a specific location of the first satellite base station,
How to receive signals.

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