Terminal and Communication Method

Abstract

Provided is a terminal that communicates with a base station via a satellite or via an aerial vehicle, said terminal comprising: a reception unit that receives, from the base station, a parameter for updating a timing advance value for communication with the base station; and a control unit that changes the method of updating the timing advance value when the parameter is updated.

Description

Technical Field

[0001] The present invention relates to a terminal and a communication method in a wireless communication system.

Background Art

[0002] In NR (New Radio) (also referred to as "5G"), which is a successor system to LTE (Long Term Evolution), technologies that satisfy requirements such as a large-capacity system, high data transmission speed, low latency, simultaneous connection of a large number of terminals, low cost, and power saving are being studied (for example, Non-Patent Document 1).

[0003] Currently, NTN (Non-Terrestrial Network) is also being studied. NTN uses a non-terrestrial network such as a satellite (hereinafter referred to as a satellite) to provide services to areas that cannot be covered mainly in terms of cost by a terrestrial 5G network.

[0004] In NR Release 17, technologies for performing time or frequency synchronization based on satellite orbits are being studied. For example, a terminal shares satellite orbit data from a base station. The terminal can calculate a value indicating timing advance for a service link or perform pre-correction or post-correction of Doppler shift for frequency correction based on the satellite orbit data and the position information obtained by GNSS (Global Navigation Satellite System).

Prior Art Documents

Non-Patent Documents

[0005]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Conventionally, in a non-terrestrial network, when satellite orbit data and the like shared from a base station are updated, the value indicating the timing advance calculated by a terminal changes rapidly, so there is a problem that the correction of time or frequency is inappropriate.

[0007] The present invention has been made in view of the above points, and an object thereof is to realize appropriate correction of time or frequency in a non-terrestrial network.

Means for Solving the Problems

[0008] According to the disclosed technology, there is provided a terminal that relays a satellite or an aircraft and communicates with a base station, the terminal including: a receiving unit that receives from the base station a parameter for updating a value of timing advance in communication with the base station; and a control unit that changes a method for updating the value of the timing advance when the parameter is updated. Divide the validity period of the parameter, and for each of the divided validity periods, A terminal including the above is provided.

Effects of the Invention

[0009] According to the disclosed technology, there is provided a technology that enables appropriate correction of time or frequency in a non-terrestrial network.

Brief Description of the Drawings

[0010]

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Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments described below are merely examples, and the embodiments to which the present invention is applied are not limited to the following embodiments.

[0012] In the operation of the wireless communication system according to the embodiment of the present invention, existing technologies may be used as appropriate. The existing technology is, for example, existing NR or LTE, but is not limited to existing NR or LTE. In addition, the term "LTE" used in this specification shall have a broad meaning including LTE-Advanced and subsequent systems (e.g., NR) unless otherwise specified.

[0013] In addition, in the embodiments of the present invention described below, terms such as SS (Synchronization signal), PSS (Primary SS), SSS (Secondary SS), PBCH (Physical broadcast channel), PRACH (Physical random access channel), PDCCH (Physical Downlink Control Channel), PDSCH (Physical Downlink Shared Channel), PUCCH (Physical Uplink Control Channel), and PUSCH (Physical Uplink Shared Channel) used in existing LTE are used. This is for convenience of description, and signals, functions, etc. similar to these may be called by other names. Also, the above terms in NR correspond to NR-SS, NR-PSS, NR-SSS, NR-PBCH, NR-PRACH, etc. However, even for signals used in NR, the "NR-" is not necessarily specified.

[0014] In addition, in the embodiments of the present invention, the duplex mode may be a TDD (Time Division Duplex) mode, an FDD (Frequency Division Duplex) mode, or other modes (e.g., Flexible Duplex, etc.).

[0015] In addition, in the embodiments of the present invention, the wireless parameters and the like being "configured" may mean that predetermined values are pre-configured, or that the wireless parameters notified from the base station or the terminal are configured.

[0016] FIG. 1 is a first diagram for explaining a non-terrestrial network. A non-terrestrial network (NTN) uses devices existing non-terrestrially such as satellites to provide services to areas that cannot be covered mainly in terms of cost in a terrestrial 5G network. Also, NTN can supply more reliable services. For example, it is assumed to be applied to IoT (Internet of Things), ships, buses, trains, and critical communications. Also, NTN has scalability by efficient multicast or broadcast.

[0017] As an example of NTN, as shown in FIG. 1, the satellite 10A can retransmit the signal transmitted from the terrestrial base station 10B and provide services to an area where no terrestrial base station is arranged, such as a mountainous area.

[0018] Note that the terrestrial 5G network may have the following configuration. The terrestrial 5G network includes one or more base stations 10 and terminals 20. The base station 10 is a communication device that provides one or more cells and performs wireless communication with the terminal 20. The physical resources of the wireless signal are defined in the time domain and the frequency domain. The time domain may be defined by the number of OFDM symbols, and the frequency domain may be defined by the number of subcarriers or the number of resource blocks. The base station 10 transmits the synchronization signal and the system information to the terminal 20. The synchronization signal is, for example, NR-PSS and NR-SSS. The system information is transmitted, for example, by NR-PBCH and is also called notification information.

[0019] The base station 10 transmits control signals or data to the terminal 20 in the DL (Downlink) and receives control signals or data from the terminal 20 in the UL (Uplink). Both the base station 10 and the terminal 20 are capable of performing beamforming for signal transmission and reception. Also, both the base station 10 and the terminal 20 are capable of applying communication by MIMO (Multiple Input Multiple Output) to the DL or UL. Further, both the base station 10 and the terminal 20 may communicate via SCell (Secondary Cell) and PCell (Primary Cell) by CA (Carrier Aggregation).

[0020] The terminal 20 is a communication device equipped with a wireless communication function such as a smartphone, a mobile phone, a tablet, a wearable terminal, a communication module for M2M (Machine-to-Machine), etc. The terminal 20 utilizes various communication services provided by the wireless communication system by receiving control signals or data from the base station 10 in the DL and transmitting control signals or data to the base station 10 in the UL.

[0021] FIG. 2 is a second diagram for explaining the non-terrestrial network. The area for each cell or beam in the NTN is very wide compared to the terrestrial network (TN). FIG. 2 shows an example of the NTN configured by satellite retransmission. The connection between the satellite 10A and the NTN gateway 10B is called a feeder link, and the connection between the satellite 10A and the UE 20 is called a service link.

[0022] As shown in FIG. 2, the difference in delay between the UE 20A on the near side and the UE 20B on the far side is, for example, 10.3 ms in the case of GEO (Geosynchronous orbit) and 3.2 ms in the case of LEO (Low Earth orbit). Also, the beam size in the NTN is, for example, 3500 km in the case of GEO and 1000 km in the case of LEO.

[0023] FIG. 3 is a third diagram for explaining a non-ground-based network. As shown in FIG. 3, NTN is realized by a satellite in space or an aircraft in the air. For example, a GEO satellite may be a satellite located at an altitude of 35,786 km and having a geostationary orbit. For example, a LEO satellite may be a satellite located at an altitude of 500 - 2000 km and orbiting with a period of 88 - 127 minutes. For example, a HAPS (High Altitude Platform Station) may be an aircraft located at an altitude of 8 - 50 km and performing a turning flight.

[0024] As shown in FIG. 3, the GEO satellite, the LEO satellite, and the HAPS aircraft may be connected to the ground station gNB via a gateway. Also, the service area may increase in the order of HAPS, LEO, and GEO.

[0025] For example, with NTN, the coverage of the 5G network can be extended to areas that are not being served or areas that are being served. Also, for example, with NTN, the continuity, availability, and reliability of services in ships, buses, trains, or other critical communications can be improved. Note that being NTN may be notified by transmitting dedicated parameters to the terminal 20, and the dedicated parameters may be parameters related to the determination of TA (Timing Advance) based on information related to, for example, a satellite or an aircraft.

[0026] FIG. 4 is a fourth diagram for explaining a non-terrestrial network. FIG. 4 shows an example of the network architecture of NTN assumed for the case of a transparent payload. As shown in FIG. 4, a CN (Core Network) 10D, a gNB 10C, and a gateway 10B are connected. The gateway 10B is connected to a satellite 10A via a feeder link. The satellite 10A is connected to a terminal 20A or a VSAT (Very Small Aperture Terminal) 20B via a service link. NR Uu is established between the gNB 10C and the terminal 20A or the VSAT 20B.

[0027] Also, as an assumption of the network architecture of NTN, FDD may be adopted, or TDD may be possible. Also, the terrestrial cells may be fixed or mobile. Also, the terminal 20 may have GNSS (Global Navigation Satellite System) capabilities. For example, in FR1, a hand-held device of power class 3 may be assumed. Also, at least in FR2, a VSAT device may be assumed.

[0028] Also, the network architecture of NTN may assume a regenerative payload. For example, the gNB function may be mounted on a satellite or an aircraft. Also, the gNB-DU may be mounted on a satellite or an aircraft, and the gNB-CU may be arranged as a ground station.

[0029] In NTN, it is necessary to consider long propagation delays, the movement of LEO or HAPS, and communication via GEO, LEO, or HAPS. Due to such characteristics of NTN, strengthening the HARQ operation is being considered. For example, the HARQ feedback may be disabled. When the HARQ feedback is disabled, two consecutive DL transport blocks can be transmitted in one HARQ process without waiting for the feedback.

[0030] FIG. 5 is a diagram for explaining the enhancement of timing advance. In the prior art such as NR, the downlink or uplink timing is adjusted only at the reference point (RP). That is, the downlink and uplink timings are adjusted to be aligned at the RP. The RP is flexibly determined according to the network implementation between the terrestrial base station 10C or gateway 10B and the satellite 10A or HAPS. Hereinafter, the terrestrial base station 10C and the gateway 10B are collectively referred to as the base station 10. Also, when the terminal 20A and the VSAT 20B are not distinguished, they are collectively referred to as the terminal 20.

[0031] At the RP in the base station 10, it is necessary to frequently broadcast information via the feeder link for simple network implementation. Also, at the RP in the satellite 10A or HAPS, backward compatibility of the playback payload or ISL / IAL is required.

[0032] The terminal 20A may calculate the value TA of the timing advance Full by the following formula.

[0033] TA Full = TA フィーダリンク + TA サービスリンク

[0034] Here, TA フィーダリンク is the RTD (round trip delay) in the feeder link and is calculated by 2(T0 + T2).

[0035] T2 is a value indicating the timing advance that is compensated by the network and is transparent to the user. T2 may be a constant to simplify the implementation of the base station 10.

[0036] T0 is a value indicating the timing advance common to all users and is broadcast by the SIB. Note that the reference point may be on the service link, and in that case, T0 is a negative value.

[0037] TA サービスリンク is the RTD in the service link and is calculated by 2T1. T1 is the TA specific to the terminal and has different values depending on the location of the terminal.

[0038] FIG. 6 is a flowchart showing an example of the flow of calculating the timing advance. The terminal 20 calculates a value indicating the timing advance between the initial access and the RACH procedure.

[0039] The base station 10 transmits an SSB (Synchronization Signal Block) to the terminal 20 (step S1). The terminal 20 performs time or frequency synchronization in the downlink and detects the MIB (Master Information Block) included in the SSB.

[0040] Next, the base station 10 transmits CORESET (Control-resource set) #0 to the terminal 20. The terminal 20 detects the SIB (System Information Block) included in CORESET #0 and acquires the PRACH resource and the parameters of the common TA.

[0041] Subsequently, the terminal 20 transmits a preamble using the common TA determined from the parameters included in the SIB and the self-estimated terminal-specific TA (step S3). The preamble includes Msg1 or MsgA in the RACH procedure.

[0042] Subsequently, the base station 10 transmits a RAR (Random Access Response) including a TAC (Timing Advance Command) to the terminal 20 (step S4). The RAR including the TAC includes Msg2 or MsgB in the RACH procedure. Based on the TAC, N TA is determined. The terminal 20 uses the common TA determined from the parameters included in the SIB, the self-estimated terminal-specific TA, and the TAC included in the RAR for uplink synchronization.

[0043] In NR NTN, a combination of open-loop and closed-loop TA control in the RRC_CONNECTED state is being considered. However, how to combine open-loop and closed-loop TA control remains an issue to be studied. Note that the names of open-loop TA control or closed-loop TA control in the following description are just examples, and others are also possible.

[0044] Also, in NR NTN, the TA applied to the terminal is considered to be composed of four parts: N TA 、N TA,common 、N TA,UE-specific and N TA,offset , and the TA is given by T TA =(N TA +N TA,common +N TA,UE-specific +N TA,offset )×T C . Also, the update method of N TA is being studied. However, the update methods of N TA,common and N TA,UE-specific remain issues to be studied.

[0045] FIG. 7 is a diagram for explaining a conventional method of calculating timing advance. In the case of open-loop TA control, the terminal 20 estimates the common TA (N TA,common ) and the terminal-specific TA (N TA,UE-specific ) with the help of some assistance information. Hereinafter, the TA updated by open-loop TA control is referred to as the open-loop TA value (the first TA value).

[0046] For example, in the estimation of the common TA in the terminal 20, the common TA parameter is broadcast by the base station 10. The common TA parameter is assistance information for calculating the common TA.

[0047] In addition, in order to reduce the complexity of the processing in the terminal 20, an expiration period can be defined to reduce the number of times of obtaining new common TA parameters. Further, the terminal 20 uses the satellite orbit parameters broadcast from the base station 10 and the data indicating the position of the terminal 20 based on GNSS for estimating the terminal-specific TA.

[0048] In the case of closed-loop TA control, the terminal 20 updates N based on the TAC field of the MAC-CE. TA This may include errors caused by inaccurate TA estimation. Hereinafter, the TA updated by the closed-loop TA control is referred to as a closed-loop TA value (second TA value).

[0049] FIG. 8 is a diagram for explaining the occurrence of errors in the prior art. When the difference between the actual common TA 901 to be estimated and the estimated common TA 902 becomes large, the common TA or the terminal-specific TA is updated based on new parameters (common TA parameters, satellite orbit data, GNSS correction, etc.). Therefore, as shown in FIG. 8, the common TA or the terminal-specific TA changes abruptly at the time of the update. At this time, if the old N determined or updated based on the old parameters is used as it is, a large error will occur. TA If it is used as it is, a large error will occur.

[0050] (Outline of the present embodiment) Therefore, in the present embodiment, a combination method of open-loop TA control and closed-loop TA control will be described. That is, in the present embodiment, a method for calculating TA for suppressing or reducing a mismatch occurring at the time of updating common TA parameters is shown. Hereinafter, specific examples 1 to 5 of the present embodiment will be described.

[0051] (Example 1) In the method for calculating TA according to this example, the terminal 20 calculates the open-loop TA value and the closed-loop TA value independently and directly combines them.

[0052] FIG. 9 is a diagram for explaining the method for calculating TA according to Embodiment 1. In the following figures, for the sake of explanation, the terminal-specific TA and the fixed value N TA,offset are not considered, but the same method as the common TA is applicable to the terminal-specific TA, and N TA,offset may be applied as described above. The solid line 911 indicates the common TA estimated based on the broadcast common TA parameter before the update. The solid line 912 indicates the common TA estimated based on the broadcast common TA parameter after the update.

[0053] The solid line 913 indicates the TA to be actually used, which is the value to be estimated. The dashed line 914 is the sum of the common TA and N TA before the update. The dashed line 915 is the sum of the common TA and N TA after the update.

[0054] In the method for calculating TA according to this embodiment, the terminal 20 directly adds the open-loop TA value and the closed-loop TA value, that is, N TA N TA,common N TA,UE-specific and N TA,offset as they are. Therefore, it is simple and easy to implement. However, as shown by the dashed line 916, when the common TA parameter is updated, due to the correction based on N TA , the sum of the updated common TA and N TA shown by the dashed line 915 deviates from the TA to be actually used shown by the solid line 913.

[0055] (Embodiment 2) In the method for calculating TA according to this embodiment, when at least one of one or more parameters related to the open-loop TA value, for example, the common TA parameter, satellite orbit data, and GNSS correction of the terminal 20 is updated, the terminal 20 changes the closed-loop TA control method when updating the open-loop TA value (for example, updates N TA ).

[0056] <Option 1> The terminal 20 N TAIt may be changed (initialized) to a preset value. For example, the terminal 20 sets N TA to 0, the N of the RACH procedure TA to its initial value or N TA to a fraction. The fraction of N TA may be, for example, N TA / 2, N TA / 3, N TA / 4, 3N TA / 4, 2N TA / 3, etc.

[0057] FIG. 10 is a diagram for explaining a method of calculating TA according to Option 1 of Example 2. The solid line 921 indicates the sum of the common TA estimated based on the broadcast common TA parameter before update and N TA The solid line 922 indicates the sum of the common TA estimated based on the broadcast common TA parameter after update and N TA .

[0058] The solid line 923 indicates the TA to be actually used, which is the value to be estimated. The dashed line 924 is the sum of the common TA before update and N TA . The dashed line 925 is the sum of the common TA after update and N TA .

[0059] In the method of calculating TA according to Option 1 of this embodiment, when the common TA parameter is updated, the terminal 20 changes the value of N TA and adds the open-loop TA value and the closed-loop TA value, that is, N TA , N TA,common , N TA,UE-specific and N TA,offset .

[0060] As shown by the dashed line 926, when the common TA parameter is updated, the terminal 20 changes the value of N TA and performs correction based on the changed value of N TA . As a result, the sum of the common TA after update and N TA shown by the dashed line 925 has less deviation from the TA to be actually used shown by the solid line 923 than in Example 1.

[0061] <Option 2> When updating parameters related to one or more open loops, the terminal 20 may newly execute the RACH procedure to obtain N TA obtain.

[0062] FIG. 11 is a diagram for explaining a method of calculating TA according to Option 2 of Example 2. As shown in FIG. 11, when parameters related to one or more open loops, that is, common TA parameters, satellite orbit data, etc. are updated in the terminal 20, a new RACH procedure is executed. As a result, the updated common TA does not depend on N calculated before the update TA but newly obtains the TA value, so that the deviation from the actual common TA is less than that in Example 1.

[0063] <Option 3> The terminal 20 may stop (i.e., not execute) the timeAlignmentTimer or consider the timer to have expired. The terminal 20 can re-acquire the TA value by setting the situation as if the timer that was running when the TA value was normal has stopped. As a result, the updated common TA does not depend on N calculated before the update TA but newly obtains the TA value, so that the deviation from the actual common TA is less than that in Example 1.

[0064] (Example 3) In the method of calculating TA according to this embodiment, when at least one of one or more parameters related to the open loop TA value, for example, the common TA parameter, the satellite orbit data, and the GNSS correction of the terminal 20 is updated, the terminal 20 changes the open loop TA value combined with the closed loop TA value.

[0065] <Option 1> The terminal 20 may shorten the validity period of the common TA parameter or the satellite orbit data. Thereby, the TA error generated when the common TA parameter or the satellite orbit data is updated can be reduced.

[0066] FIG. 12 is a diagram for explaining a method for calculating TA according to Option 1 of Embodiment 3. The solid line 931 indicates the sum of the common TA and N estimated based on the broadcast common TA parameter before update. TA The solid line 932 indicates the sum of the common TA and N estimated based on the broadcast common TA parameter after update. TA

[0067] The solid line 933 indicates the TA to be actually used, which is the value to be estimated. The dashed line 934 is the sum of the common TA and N before update. TA The dashed line 935 is the sum of the common TA and N after update. TA

[0068] In the method for calculating TA according to Option 1 of this embodiment, since the validity period of the common TA parameter or satellite orbit data is short at the terminal 20, the update frequency is higher than that in Embodiment 1. Therefore, as shown by the dashed line 936, the magnitude of the deviation of the sum of the common TA and N updated by the correction based on N when the common TA parameter is updated from the TA to be actually used shown by the solid line 933 can be made smaller than that in Embodiment 1. The same applies to the terminal-specific TA. TA The sum of the common TA and N after being updated by the correction based on N when the common TA parameter is updated TA

[0069] Also, the terminal 20 directly adds the open-loop TA value and the closed-loop TA value, that is, N TA N TA,common N TA,UE-specific and N TA,offset . Therefore, the implementation is simple and the impact on the specification is small.

[0070] <Option 2> When parameters related to the open-loop TA value are updated at the terminal 20, the formula or calculation method for updating the open-loop TA may be changed.

[0071] <Option 2-1> ​​​The terminal 20 may gradually update the open-loop TA value. For example, the validity period of one of the parameters is divided into N parts. The lengths of each part may or may not be equal.

[0072] In the nth part, at least one of N TA,common , N TA,UE-specific is updated by a new function f n is defined. That is, at least one of N TA,common,new = f n (N TA,common,old , the updated common TA parameter), N TA,UE-specific,new = f n (N TA,UE-specific,old , the updated common TA parameter) is defined.

[0073] For example, the common TA is updated to an expression that is gradually updated. For example, N TA,common,new = N TA,common,old + (N TA,common,new - N TA,common,old ) * n / N. Here, N is an integer.

[0074] Similarly, the terminal-specific TA is updated to an expression that is gradually updated. For example, N TA,UE-specific,new = N TA,UE-specific,old + (N TA,UE-specific,new - N TA,UE-specific,old ) * n / N. Here, N is an integer.

[0075] Similarly, an expression that sums up the update of the common TA and the update of the terminal-specific TA may be gradually updated.

[0076] FIG. 13 is a diagram for explaining a method of calculating TA according to Option 2-1 of Example 3. FIG. 13 shows a method of calculating the common TA when the validity period of the parameter is divided into N = 3 in the function fn for updating the above-mentioned common TA. The solid line 941 indicates the sum of the common TA estimated based on the broadcast common TA parameter before update and N TA . The solid line 942 indicates the sum of the common TA estimated based on the broadcast common TA parameter after update and N TA .

[0077] The solid line 943 indicates the TA to be actually used and the value to be estimated. The dashed line 944 is the sum of the common TA and N before update. TA The dashed line 945 is the sum of the common TA and N TA after update.

[0078] In the method for calculating the TA according to Option 2-1 of this embodiment, the terminal 20 gradually updates the common TA. Therefore, as shown by the dashed line 946, when the common TA parameter is updated, the sum of the common TA and N TA updated by the correction based on N can be made smaller than that in Embodiment 1 in terms of the deviation from the TA to be actually used shown by the solid line 943. The same applies to the terminal-specific TA. TA

[0079] <Option 2-2> The terminal 20 may use a new approximation function of the open-loop TA value based on the old and new open-loop TA values. For example, the terminal 20 may use a new continuous function that starts from the TA value before update and stops at the end of the valid period.

[0080] FIG. 14 is a diagram for explaining the method for calculating the TA according to Option 2-2 of Embodiment 3. The solid line 961 indicates the sum of the common TA and N estimated based on the broadcast common TA parameter a(t) before update. TA The solid line 962 indicates the sum of the common TA and N estimated using the continuous function g(a(t), b(t)) based on the broadcast common TA parameter a(t) before update and the broadcast common TA parameter b(t) after update. TA

[0081] The solid line 963 indicates the TA to be actually used and the value to be estimated. The dashed line 964 is the sum of the common TA and N before update. TA The dashed line 965 is the sum of the common TA and N after update. TA

[0082] ​​​ In the TA calculation method according to Option 2-2 of this embodiment, the terminal 20 updates the common TA based on a new approximation function. Therefore, when the common TA parameter is updated, the sum of the common TA and N TA after being updated by the correction based on N TA can be maintained close to the TA that should actually be used, as shown by the solid line 943. The same applies to the terminal-specific TA.

[0083] <Option 3> In order to reduce the TA error when updating the open-loop assistance parameters, that is, to offset the influence of the inaccuracy of the open-loop TA value on N TA the terminal 20 may use a new fitting function for the open-loop TA value and the corresponding fitting parameters.

[0084] The terminal 20 may use new common TA parameters to fit a common TA that has small errors at the beginning and end of the validity period and large errors in the middle of the validity period.

[0085] Also, the terminal 20 may use the formula for terminal-specific TA fitting to reduce the fitting error when updating the terminal-specific TA (for example, updating satellite orbit data or GNSS corrections).

[0086] FIG. 15 is a first diagram for explaining the TA calculation method according to Option 3 of Embodiment 3. FIG. 15 shows the original fitting function based on Taylor's formula. The terminal 20 may use the newly defined fitting function y(t)=f(x(t0),t) in the validity period [T1,T2].

[0087] Here, x(t0) is the open-loop TA parameter at the reference time t0, which may include a plurality of parameters. y(t) is the open-loop TA value estimated at the time t within the validity period. T1≦t0,t≦T2.

[0088] The fitting function may be a function obtained based on Taylor's formula by selecting a reference time t0, a fitting order (e.g., 0 / 1 / 2 order), fitting parameters (e.g., x0(t0), first derivative x1(t0), second derivative x2(t0)), etc.

[0089] 0th-order Taylor approximation: y est,0 (t) = x0(t0) 1st-order Taylor approximation: y est,1 (t) = x0(t0) + x1(t0)·(t - t0) 2nd-order Taylor approximation: y est,2 (t) = x0(t0) + x1(t0)·(t - t0) + x2(t0)·(t - t0) 2 / 2

[0090] The solid line 973 indicates the common TA estimated based on the parameters. x(t0) includes the common TA and the first derivative of the common TA. For example, the parameters related to the estimation of the common TA are derived from the actual common TA at time t0.

[0091] In this case, the approximation error is minimized at the reference time t0. That is, y(t0) indicated by point 971 is closest to the actual value. When |t - t0| is large, the approximation is not accurate. As a result, a large error may occur before updating the parameters.

[0092] FIG. 16 is a second diagram for explaining the method for calculating the TA according to Option 3 of Example 3. FIG. 16 shows a new fitting function considering the requirements of the combination of closed-loop and open-loop TA controls.

[0093] The requirements of the combination of closed-loop and open-loop TA controls mean that instead of the fitting error at T1 < t < T2 of y(t) = f(x(t0), t) possibly becoming large, y(T1) and y(T2) approach the actual values.

[0094] The solid line 983 indicates the common TA estimated based on parameters. x(t0) includes the potential parameters required for the estimation. The common TA is derived from the actual common TA at time t0 and the validity period [T1, T2].

[0095] In the method for calculating TA according to Option 3 of this embodiment, the terminal 20 updates the common TA using a new fitting function and the corresponding fitting parameters. Therefore, when the common TA parameter is updated, the common TA updated by the correction based on N TA can be maintained at a value close to the actual common TA. The same applies to the terminal-specific TA.

[0096] <Option 4> The terminal 20 uses at least one of the maximum update step of the common TA as T step,common or the maximum update step of the terminal-specific TA as T step,UE-specific or may use the maximum update step of the open-loop TA as T step,open-loop . Note that similar to the maximum update step of N TA in both non-terrestrial and terrestrial networks, when updating the open-loop TA value, the update gap needs to be smaller than the maximum update step.

[0097] For example, the terminal 20 may use the following formula in updating the common TA.

[0098] N TA,common = N TA,common,old + min((N TA,common,new - N TA,common,old ) * Tc, T step,common )

[0099] Similarly, the terminal 20 may use the following formula in updating the terminal-specific TA.

[0100] N TA,UE-specific = N TA,UE-specific,old + min((N TA,UE-specific,new - N TA,UE-specific,old ) * Tc, Tstep,UE-specific )

[0101] The maximum update step of the open-loop TA value may be predefined in the specification. Alternatively, the base station 10 may determine the maximum update step and notify the terminal 20 via SIB, RRC, MAC-CE, DCI, etc.

[0102] In the TA calculation method according to Option 4 of this embodiment, the terminal 20 updates the TA within the range of the maximum update step of the open-loop TA. Therefore, the deviation of the common TA after being updated by the correction based on N when the common TA parameter is updated can be suppressed to be smaller than the specified value. The same applies to the terminal-specific TA. TA After being updated by the correction based on N when the common TA parameter is updated, the deviation of the common TA can be suppressed to be smaller than the specified value. The same applies to the terminal-specific TA.

[0103] (Embodiment 4) In the TA calculation method according to this embodiment, when at least one of one or more parameters related to the open-loop TA value, such as the common TA parameter, satellite orbit data, and GNSS correction of the terminal 20, is updated, the terminal 20 changes both the closed-loop TA value and the open-loop TA value.

[0104] When updating the parameters, the terminal 20 may combine and use the methods and options of Embodiment 2 and Embodiment 3 described above. For example, the terminal 20 may gradually update the closed-loop TA value and the open-loop TA value.

[0105] In the TA calculation method according to this embodiment, the terminal 20 changes both the closed-loop TA value and the open-loop TA value. Therefore, the deviation of the common TA after being updated by the correction based on N when the common TA parameter is updated can be suppressed to be smaller. The same applies to the terminal-specific TA. TA After being updated by the correction based on N when the common TA parameter is updated, the deviation of the common TA can be suppressed to be smaller. The same applies to the terminal-specific TA.

[0106] (Embodiment 5) In this embodiment, UE Capability is defined regarding the support for RRC configuration based on closed-loop and open-loop TA update methods, related signaling reports, and notifications of UE Capability.

[0107] As UE Capability, information indicating whether the terminal 20 supports an independent or combined combination of closed-loop and open-loop TA values may be defined.

[0108] Also, as UE Capability, information indicating whether at least one of the open-loop TA value and the closed-loop TA value is updated and the update method when the terminal 20 updates one or more open-loop TA-related support parameters (for example, common TA parameter, satellite orbit data update, GNSS correction of the terminal, etc.) may be defined.

[0109] Specifically, the UE Capability is as follows. · UE Capability regarding whether to support a short validity period of open-loop TA parameters (such as common TA parameters, satellite orbit data, etc.) · UE Capability regarding whether to support stepwise update of open-loop TA values · UE Capability regarding whether to support complex fitting functions and parameters of open-loop TA estimation · N TA · UE Capability regarding whether to support resetting N to one predefined value · New N TA · UE Capability regarding whether to support execution of a new RACH procedure to obtain a new N · UE Capability regarding whether the terminal stops the timeAlignmentTimer (that is, does not execute it) or the terminal considers the timeAlignmentTimer expired · UE Capability regarding whether to support the maximum update step of open-loop TA values

[0110] The terminal may report its capabilities to the base station. Based on the reported terminal capabilities, the base station may set at least any one of the options of each of the above-described embodiments.

[0111] (Device Configuration) Next, a functional configuration example of the base station 10 and the terminal 20 that execute the processes and operations described so far will be described. The base station 10 and the terminal 20 include functions for executing the above-described embodiments. However, the base station 10 and the terminal 20 may each be provided with only the functions of any one of the proposals in the embodiments.

[0112] <Base Station 10> FIG. 17 is a diagram showing an example of the functional configuration of the base station 10. As shown in FIG. 17, the base station 10 includes a transmission unit 110, a reception unit 120, a setting unit 130, and a control unit 140. The functional configuration shown in FIG. 17 is merely an example. As long as the operations according to the embodiments of the present invention can be executed, the functional divisions and the names of the functional units may be any. The transmission unit 110 and the reception unit 120 may be referred to as a communication unit.

[0113] The transmission unit 110 includes functions of generating a signal to be transmitted to the terminal 20 side and wirelessly transmitting the signal. The reception unit 120 includes functions of receiving various signals transmitted from the terminal 20 and obtaining information of a higher layer, for example, from the received signals. Also, the transmission unit 110 has functions of transmitting NR-PSS, NR-SSS, NR-PBCH, DL / UL control signals, DL data, etc. to the terminal 20. Further, the transmission unit 110 transmits the setting information and the like described in the embodiments.

[0114] The setting unit 130 stores the preset setting information and various setting information to be transmitted to the terminal 20 in a storage device and reads it out from the storage device as necessary. The control unit 140 performs, for example, control of the entire base station 10 including control related to signal transmission and reception. Note that a functional unit related to signal transmission in the control unit 140 may be included in the transmission unit 110, and a functional unit related to signal reception in the control unit 140 may be included in the reception unit 120. Also, the transmission unit 110 and the reception unit 120 may be referred to as a transmitter and a receiver, respectively.

[0115] <Terminal 20> FIG. 18 is a diagram showing an example of the functional configuration of terminal 20. As shown in FIG. 18, terminal 20 includes a transmission unit 210, a reception unit 220, a setting unit 230, and a control unit 240. The functional configuration shown in FIG. 18 is merely an example. As long as the operations according to the embodiments of the present invention can be executed, the functional division and the names of the functional units can be any. The transmission unit 210 and the reception unit 220 may be called a communication unit.

[0116] The transmission unit 210 creates a transmission signal from the transmission data and transmits the transmission signal wirelessly. The reception unit 220 wirelessly receives various signals and obtains signals of a higher layer from the received physical layer signals. Also, the transmission unit 210 transmits HARQ-ACK, and the reception unit 220 receives the setting information and the like described in the embodiments.

[0117] The setting unit 230 stores various setting information received from the base station 10 by the reception unit 220 in the storage device and reads it out from the storage device as necessary. Also, the setting unit 230 stores preset setting information. The control unit 240 performs overall control of the terminal 20 including control related to signal transmission and reception. Note that a functional unit related to signal transmission in the control unit 240 may be included in the transmission unit 210, and a functional unit related to signal reception in the control unit 240 may be included in the reception unit 220. Also, the transmission unit 210 and the reception unit 220 may be called a transmitter and a receiver, respectively.

[0118] The terminal of the present embodiment may be configured as the terminals shown in the following items. Also, the following communication methods may be implemented.

[0119] <Configuration Regarding the Present Embodiment> (Item 1) A terminal that communicates with a base station via a satellite or an aircraft, a reception unit that receives a parameter for updating the value of timing advance in the communication with the base station from the base station, A control unit that changes a method for updating the value of the timing advance when the parameter is updated. Terminal. (Item 2) The value of the timing advance includes a first TA value updated by estimation based on the parameter received from the base station and a second TA value updated based on the information received from the base station. When the parameter is updated, the control unit changes the method for updating the first TA value. The terminal according to Item 1. (Item 3) The value of the timing advance includes a first TA value updated by estimation based on the parameter received from the base station and a second TA value updated based on the information received from the base station. When the parameter is updated, the control unit changes the method for updating the second TA value. The terminal according to Item 1 or Item 2. (Item 4) A communication method executed by a terminal that communicates with a base station via a satellite or an aircraft, Receiving from the base station a parameter for updating the value of the timing advance in communication with the base station; Changing a method for updating the value of the timing advance when the parameter is updated. Communication method.

[0120] According to any of the above configurations, a technique is provided that enables appropriate correction of time or frequency in a non-terrestrial network. According to Item 2, by updating the first TA value, the error of TA at the time of parameter update can be reduced. According to Item 3, by updating the second TA value, the error of TA at the time of parameter update can be reduced.

[0121] (Hardware Configuration) The block diagrams (Figs. 17 and 18) used in the description of the above embodiments show blocks in terms of functions. These functional blocks (components) are realized by any combination of at least one of hardware and software. Also, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one physically or logically combined device, or two or more physically or logically separated devices may be directly or indirectly (e.g., using wired, wireless, etc.) connected and realized using these multiple devices. The functional block may be realized by combining software with the above one device or the above multiple devices.

[0122] Functions include, but are not limited to, judgment, decision, determination, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, solution, selection, selection determination, establishment, comparison, assumption, expectation, regarded as, notification (broadcasting), notice (notifying), communication (communicating), forwarding, configuration (configuring), reconfiguration (reconfiguring), allocation (allocating, mapping), assignment (assigning), etc. For example, a functional block (component) that functions as transmission is called a transmitting unit or a transmitter. In any case, as described above, the realization method is not particularly limited.

[0123] For example, the base station 10, the terminal 20, etc. in an embodiment of the present disclosure may function as a computer that performs the processing of the wireless communication method of the present disclosure. Fig. 19 is a diagram showing an example of the hardware configuration of the base station 10 and the terminal 20 according to an embodiment of the present disclosure. The above-described base station 10 and terminal 20 may physically be configured as a computer device including a processor 1001, a storage device 1002, an auxiliary storage device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like.

[0124] In the following description, the term "apparatus" can be read as a circuit, device, unit, etc. The hardware configurations of the base station 10 and the terminal 20 may be configured to include one or more of the apparatuses shown in the figure, or may be configured without including some of the apparatuses.

[0125] Each function in the base station 10 and the terminal 20 is realized by causing a processor 1001 to perform operations and control communication by a communication device 1004, or by controlling at least one of reading and writing of data in a storage device 1002 and an auxiliary storage device 1003, by loading a predetermined software (program) onto hardware such as the processor 1001 and the storage device 1002.

[0126] The processor 1001 controls the entire computer by operating, for example, an operating system. The processor 1001 may be composed of a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic device, a register, etc. For example, the above-described control units 140, 240, etc. may be realized by the processor 1001.

[0127] Also, the processor 1001 reads a program (program code), software module, data, etc. from at least one of the auxiliary storage device 1003 and the communication device 1004 into the storage device 1002, and executes various processes according to these. As the program, a program that causes a computer to execute at least a part of the operations described in the above-described embodiments is used. For example, the control unit 140 of the base station 10 shown in FIG. 17 may be stored in the storage device 1002 and realized by a control program that operates on the processor 1001. Also, for example, the control unit 240 of the terminal 20 shown in FIG. 18 may be stored in the storage device 1002 and realized by a control program that operates on the processor 1001. Although it has been described that the above-described various processes are executed by one processor 1001, they may be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented by one or more chips. Note that the program may be transmitted from a network via a telecommunication line.

[0128] The storage device 1002 is a computer-readable recording medium and may be constituted by at least one of, for example, ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), RAM (Random Access Memory), etc. The storage device 1002 may be referred to as a register, cache, main memory (main storage device), etc. The storage device 1002 can store a program (program code), software module, etc. executable for implementing the communication method according to an embodiment of the present disclosure.

[0129] The auxiliary storage device 1003 is a computer-readable recording medium, and may be constituted by, for example, at least one of an optical disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto-optical disk (for example, a compact disk, a digital versatile disk, a Blu-ray (registered trademark) disk), a smart card, a flash memory (for example, a card, a stick, a key drive), a floppy (registered trademark) disk, a magnetic strip, etc. The above-described storage medium may be, for example, a database, a server, or other appropriate medium including at least one of the storage device 1002 and the auxiliary storage device 1003.

[0130] The communication device 1004 is hardware (a transmission / reception device) for performing communication between computers via at least one of a wired network and a wireless network, and is also referred to as, for example, a network device, a network controller, a network card, a communication module, etc. The communication device 1004 may be configured to include, for example, a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. in order to realize at least one of frequency division duplex (FDD:Frequency Division Duplex) and time division duplex (TDD:Time Division Duplex). For example, a transmission / reception antenna, an amplifier unit, a transmission / reception unit, a transmission line interface, etc. may be realized by the communication device 1004. The transmission / reception unit may be physically or logically separated into a transmission unit and a reception unit.

[0131] The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives an external input. The output device 1006 is an output device (for example, a display, a speaker, an LED lamp, etc.) that performs an output to the outside. Note that the input device 1005 and the output device 1006 may have an integrated configuration (for example, a touch panel).

[0132] Also, each device such as the processor 1001 and the storage device 1002 is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus or may be configured using different buses for each device.

[0133] Also, the base station 10 and the terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), and a field programmable gate array (FPGA), and some or all of each functional block may be realized by the hardware. For example, the processor 1001 may be implemented using at least one of these hardware components.

[0134] FIG. 20 shows a configuration example of the vehicle 2001. As shown in FIG. 20, the vehicle 2001 includes a drive unit 2002, a steering unit 2003, an accelerator pedal 2004, a brake pedal 2005, a shift lever 2006, front wheels 2007, rear wheels 2008, an axle 2009, an electronic control unit 2010, various sensors 2021 to 2029, an information service unit 2012, and a communication module 2013. Each aspect / embodiment described in the present disclosure may be applied to a communication device mounted on the vehicle 2001, and for example, may be applied to the communication module 2013.

[0135] The drive unit 2002 is composed of, for example, an engine, a motor, or a hybrid of an engine and a motor. The steering unit 2003 includes at least a steering wheel (also called a handle), and is configured to steer at least one of the front wheels and the rear wheels based on an operation of the steering wheel operated by a user.

[0136] The electronic control unit 2010 is composed of a microprocessor 2031, a memory (ROM, RAM) 2032, and a communication port (IO port) 2033. Signals from various sensors 2021 to 2029 provided in the vehicle 2001 are input to the electronic control unit 2010. The electronic control unit 2010 may also be called an ECU (Electronic Control Unit).

[0137] Signals from the various sensors 2021 to 2029 include a current signal from a current sensor 2021 that senses the current of the motor, a rotational speed signal of the front and rear wheels obtained by a rotational speed sensor 2022, an air pressure signal of the front and rear wheels obtained by an air pressure sensor 2023, a vehicle speed signal obtained by a vehicle speed sensor 2024, an acceleration signal obtained by an acceleration sensor 2025, a depression amount signal of the accelerator pedal obtained by an accelerator pedal sensor 2029, a depression amount signal of the brake pedal obtained by a brake pedal sensor 2026, an operation signal of the shift lever obtained by a shift lever sensor 2027, a detection signal for detecting obstacles, vehicles, pedestrians, etc. obtained by an object detection sensor 2028, and so on.

[0138] The information service unit 2012 is composed of various devices for providing various information such as driving information, traffic information, and entertainment information, such as a car navigation system, an audio system, speakers, a television, and a radio, and one or more ECUs for controlling these devices. The information service unit 2012 uses the information obtained from an external device via a communication module 2013 or the like to provide various multimedia information and multimedia services to the passengers of the vehicle 2001.

[0139] The driving assistance system unit 2030 is composed of various devices for providing functions such as preventing accidents and reducing the driver's driving load, such as millimeter-wave radars, LiDAR (Light Detection and Ranging), cameras, positioning locators (e.g., GNSS, etc.), map information (e.g., high-definition (HD) maps, autonomous vehicle (AV) maps, etc.), gyro systems (e.g., IMU (Inertial Measurement Unit), INS (Inertial Navigation System), etc.), AI (Artificial Intelligence) chips, AI processors, and one or more ECUs for controlling these devices. Also, the driving assistance system unit 2030 transmits and receives various information via the communication module 2013 to realize the driving assistance function or the autonomous driving function.

[0140] The communication module 2013 can communicate with the microprocessor 2031 and the components of the vehicle 2001 via a communication port. For example, the communication module 2013 transmits and receives data with the drive unit 2002, steering unit 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, front wheels 2007, rear wheels 2008, axle 2009, the microprocessor 2031 and memory (ROM, RAM) 2032 in the electronic control unit 2010, and sensors 2021 - 29 provided in the vehicle 2001 via the communication port 2033.

[0141] The communication module 2013 is a communication device that can be controlled by the microprocessor 2031 of the electronic control unit 2010 and can communicate with an external device. For example, it transmits and receives various information via wireless communication with an external device. The communication module 2013 may be either inside or outside the electronic control unit 2010. The external device may be, for example, a base station, a mobile station, etc.

[0142] The communication module 2013 transmits the current signal from the current sensor input to the electronic control unit 2010 to an external device via wireless communication. Further, the communication module 2013 also transmits, via wireless communication to an external device, the rotation speed signals of the front and rear wheels acquired by the rotation speed sensor 2022, the air pressure signals of the front and rear wheels acquired by the air pressure sensor 2023, the vehicle speed signal acquired by the vehicle speed sensor 2024, the acceleration signal acquired by the acceleration sensor 2025, the depression amount signal of the accelerator pedal acquired by the accelerator pedal sensor 2029, the depression amount signal of the brake pedal acquired by the brake pedal sensor 2026, the operation signal of the shift lever acquired by the shift lever sensor 2027, the detection signal for detecting obstacles, vehicles, pedestrians, etc. acquired by the object detection sensor 2028, etc., which are input to the electronic control unit 2010.

[0143] The communication module 2013 receives various information (traffic information, signal information, inter-vehicle information, etc.) transmitted from an external device and displays it to the information service unit 2012 provided in the vehicle 2001. Further, the communication module 2013 stores the various information received from the external device in the memory 2032 that can be used by the microprocessor 2031. Based on the information stored in the memory 2032, the microprocessor 2031 may control the drive unit 2002, the steering unit 2003, the accelerator pedal 2004, the brake pedal 2005, the shift lever 2006, the front wheels 2007, the rear wheels 2008, the axle 2009, the sensors 2021 to 2029, etc. provided in the vehicle 2001.

[0144] (Supplement of the embodiment) The embodiments of the present invention have been described above. However, the disclosed invention is not limited to such embodiments, and those skilled in the art will understand various variations, modifications, alternatives, substitutions, etc. Although specific numerical examples have been used for the purpose of facilitating the understanding of the invention, unless otherwise specified, those numerical values are merely examples and any appropriate values may be used. The classification of the items in the above description is not essential to the present invention, and the matters described in two or more items may be used in combination as needed, or the matters described in one item may be applied to the matters described in another item (as long as there is no contradiction). The boundaries of the functional units or processing units in the functional block diagram do not necessarily correspond to the boundaries of physical components. The operations of a plurality of functional units may be physically performed by one component, or the operation of one functional unit may be physically performed by a plurality of components. Regarding the processing procedures described in the embodiments, the order of processing may be changed as long as there is no contradiction. For the sake of convenience in explaining the processing, the base station 10 and the terminal 20 have been described using functional block diagrams, but such devices may be implemented in hardware, software, or a combination thereof. The software that operates by the processor included in the base station 10 according to the embodiment of the present invention and the software that operates by the processor included in the terminal 20 according to the embodiment of the present invention may each be stored in a random access memory (RAM), flash memory, read-only memory (ROM), EPROM, EEPROM, register, hard disk drive (HDD), removable disk, CD-ROM, database, server, or any other appropriate storage medium.

[0145] In addition, the notification of information is not limited to the aspects / embodiments described in the present disclosure, and other methods may be used. For example, the notification of information may be implemented by physical layer signaling (e.g., DCI (Downlink Control Information), UCI (Uplink Control Information)), upper layer signaling (e.g., RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, notification information (MIB (Master Information Block), SIB (System Information Block)), other signals or combinations thereof. Also, the RRC signaling may be referred to as an RRC message, and may be, for example, an RRC connection setup (RRC Connection Setup) message, an RRC connection reconfiguration (RRC Connection Reconfiguration) message, etc.

[0146] Each aspect / embodiment described in the present disclosure may be applied to at least one of systems using LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), 6th generation mobile communication system (6G), xth generation mobile communication system (xG) (x is, for example, an integer or a decimal), FRA (Future Radio Access), NR (new Radio), New radio access (NX), Future generation radio access (FX), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth (registered trademark), and other appropriate systems, as well as next-generation systems extended, modified, created, and defined based on these. Further, a plurality of systems may be combined (for example, a combination of at least one of LTE and LTE-A and 5G, etc.) and applied.

[0147] The processing procedures, sequences, flowcharts, etc. of each aspect / embodiment described in this specification may be rearranged as long as there is no contradiction. For example, for the methods described in the present disclosure, the elements of various steps are presented using an exemplary order and are not limited to the specific order presented.

[0148] The specific operations assumed to be performed by the base station 10 in this specification may, in some cases, be performed by its upper node. In a network consisting of one or more network nodes having the base station 10, various operations performed for communication with the terminal 20 can clearly be performed by at least one of the base station 10 and other network nodes other than the base station 10 (for example, but not limited to, an MME or an S-GW, etc.). Although the case where there is one other network node other than the base station 10 has been exemplified above, the other network node may be a combination of a plurality of other network nodes (for example, an MME and an S-GW).

[0149] The information or signals, etc. described in this disclosure can be output from an upper layer (or a lower layer) to a lower layer (or an upper layer). They may be input and output via a plurality of network nodes.

[0150] The input and output information, etc. may be stored in a specific location (for example, a memory), or may be managed using a management table. The input and output information, etc. can be overwritten, updated, or appended. The output information, etc. may be deleted. The input information, etc. may be transmitted to other devices.

[0151] The determination in this disclosure may be made by a value represented by 1 bit (0 or 1), may be made by a Boolean value (true or false), or may be made by a numerical comparison (for example, comparison with a predetermined value).

[0152] Software should be broadly construed to mean, whether called software, firmware, middleware, microcode, a hardware description language, or by any other name, instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc.

[0153] Also, software, instructions, information, etc. may be transmitted and received via a transmission medium. For example, when software is transmitted from a website, server, or other remote source using at least one of wired technologies (such as coaxial cables, fiber optic cables, twisted pairs, digital subscriber lines (DSL), etc.) and wireless technologies (such as infrared, microwaves, etc.), at least one of these wired and wireless technologies is included within the definition of the transmission medium.

[0154] The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc., which may be referred to throughout the above description, may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0155] Note that terms described in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol may be a signal (signaling). Also, a signal may be a message. Also, a component carrier (CC) may be referred to as a carrier frequency, a cell, a frequency carrier, etc.

[0156] The terms "system" and "network" used in this disclosure are used interchangeably.

[0157] In addition, the information, parameters, etc. described in this disclosure may be represented using absolute values, relative values from a predetermined value, or using other corresponding information. For example, radio resources may be indicated by an index.

[0158] The names used for the above-described parameters are not limiting in any way. Furthermore, mathematical formulas, etc. using these parameters may be different from those explicitly disclosed in this disclosure. Since various channels (e.g., PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name, the various names assigned to these various channels and information elements are not limiting in any way.

[0159] In this disclosure, terms such as "base station (BS:Base Station)", "radio base station", "base station", "fixed station", "NodeB", "eNodeB (eNB)", "gNodeB (gNB)", "access point", "transmission point", "reception point", "transmission / reception point", "cell", "sector", "cell group", "carrier", "component carrier", etc. may be used interchangeably. A base station may also be referred to by terms such as macrocell, small cell, femtocell, picocell, etc.

[0160] A base station can accommodate one or more (e.g., three) cells. When the base station accommodates multiple cells, the entire coverage area of the base station can be divided into multiple smaller areas, and each smaller area can also provide communication services by a base station subsystem (e.g., a small indoor base station (RRH: Remote Radio Head)). The term "cell" or "sector" refers to a part or the whole of the coverage area of at least one of the base station and the base station subsystem that provides communication services in this coverage.

[0161] In this disclosure, terms such as "mobile station (MS)", "user terminal", "user equipment (UE)", and "terminal" can be used interchangeably.

[0162] A mobile station may also be called by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other appropriate terms.

[0163] At least one of the base station and the mobile station may also be called a transmitting device, a receiving device, a communication device, etc. Note that at least one of the base station and the mobile station may also be a device mounted on a moving body, the moving body itself, etc. The moving body may be a vehicle (e.g., a car, an airplane, etc.), a moving body that moves without a driver (e.g., a drone, an autonomous vehicle, etc.), or a robot (humanoid or non-humanoid). Note that at least one of the base station and the mobile station also includes a device that does not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an IoT (Internet of Things) device such as a sensor.

[0164] In addition, the base station in the present disclosure may be replaced by a user terminal. For example, for a configuration in which communication between the base station and the user terminal is replaced with communication between a plurality of terminals 20 (which may be referred to as, for example, D2D (Device-to-Device), V2X (Vehicle-to-Everything), etc.), each aspect / embodiment of the present disclosure may be applied. In this case, the functions of the above-described base station 10 may be configured to be possessed by the terminal 20. Also, terms such as "uplink" and "downlink" may be replaced with terms corresponding to inter-terminal communication (for example, "side"). For example, the uplink channel, downlink channel, etc. may be replaced with the side channel.

[0165] Similarly, the user terminal in the present disclosure may be replaced by a base station. In this case, the functions of the above-described user terminal may be configured to be possessed by the base station.

[0166] The terms "determining" and "deciding" as used in this disclosure may encompass a wide variety of actions. "Determining" and "deciding" may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up (e.g., searching in a table, database, or another data structure), ascertaining, and considering something as having been "determined" or "decided". Further, "determining" and "deciding" may include considering something as having been "determined" or "decided" based on receiving (e.g., receiving information), transmitting (e.g., transmitting information), inputting, outputting, accessing (e.g., accessing data in a memory), etc. Additionally, "determining" and "deciding" may include considering something as having been "determined" or "decided" based on resolving, selecting, choosing, establishing, comparing, etc. That is, "determining" and "deciding" may include considering that some action has been "determined" or "decided". Also, "determining (deciding)" may be read as "assuming", "expecting", "considering", etc.

[0167] The terms "connected" or "coupled," or any variations thereof, mean any direct or indirect connection or coupling between two or more elements, and can include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements can be physical, logical, or a combination thereof. For example, "connected" may be read as "accessed." As used in this disclosure, two elements can be considered to be "connected" or "coupled" to each other using at least one of one or more wires, cables, and printed electrical connections, and also, by way of some non-limiting and non-exhaustive examples, electromagnetic energy having wavelengths in the radio frequency region, microwave region, and optical (both visible and invisible) region, etc.

[0168] The reference signal can also be abbreviated as RS (Reference Signal) and may be called a Pilot depending on the applicable standard.

[0169] As used in this disclosure, the description "based on" does not mean "based only on" unless otherwise specified. In other words, the description "based on" means both "based only on" and "based at least on."

[0170] Any reference to an element using designations such as "first," "second," etc. used in this disclosure does not generally limit the quantity or order of those elements. These designations can be used in this disclosure as a convenient way to distinguish between two or more elements. Thus, a reference to a first and a second element does not mean that only two elements can be employed, or that the first element must precede the second element in any form.

[0171] In the configuration of each of the above devices, "means" may be replaced with "section," "circuit," "device," etc.

[0172] In the present disclosure, when the terms "include", "including" and their variants are used, these terms are intended to be inclusive, in the same manner as the term "comprising". Further, the term "or" used in the present disclosure is not intended to be an exclusive disjunction.

[0173] The wireless frame may be composed of one or more frames in the time domain. Each of the one or more frames in the time domain may be referred to as a subframe. The subframe may further be composed of one or more slots in the time domain. The subframe may have a fixed time length (e.g., 1 ms) independent of numerology.

[0174] Numerology may be communication parameters applied to at least one of transmission and reception of a certain signal or channel. Numerology may indicate at least one of, for example, subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, wireless frame configuration, specific filtering processing performed by a transceiver in the frequency domain, and specific windowing processing performed by a transceiver in the time domain.

[0175] The slot may be composed of one or more symbols (OFDM (Orthogonal Frequency Division Multiplexing) symbols, SC-FDMA (Single Carrier Frequency Division Multiple Access) symbols, etc.) in the time domain. The slot may be a time unit based on numerology.

[0176] The slot may include a plurality of mini-slots. Each mini-slot may be composed of one or more symbols in the time domain. Also, the mini-slot may be referred to as a sub-slot. The mini-slot may be composed of a smaller number of symbols than the slot. The PDSCH (or PUSCH) transmitted in a time unit larger than the mini-slot may be referred to as PDSCH (or PUSCH) mapping type A. The PDSCH (or PUSCH) transmitted using the mini-slot may be referred to as PDSCH (or PUSCH) mapping type B.

[0177] The radio frame, sub-frame, slot, mini-slot, and symbol all represent time units when transmitting signals. Different names corresponding to each of them may be used.

[0178] For example, one sub-frame may be referred to as a Transmission Time Interval (TTI), or a plurality of consecutive sub-frames may be referred to as TTI, or one slot or one mini-slot may be referred to as TTI. That is, at least one of the sub-frame and TTI may be the sub-frame (1 ms) in the existing LTE, or a period shorter than 1 ms (e.g., 1 - 13 symbols), or a period longer than 1 ms. Note that the unit representing TTI may be referred to as a slot, mini-slot, etc. instead of a sub-frame.

[0179] Here, TTI refers to, for example, the minimum time unit for scheduling in wireless communication. For example, in the LTE system, the base station performs scheduling to allocate radio resources (such as the frequency bandwidth and transmission power that can be used in each terminal 20) to each terminal 20 in TTI units. Note that the definition of TTI is not limited to this.

[0180] The TTI may be a transmission time unit such as a channel-coded data packet (transport block), a code block, a codeword, etc., or may be a processing unit such as scheduling and link adaptation. When the TTI is given, the time interval (e.g., the number of symbols) in which a transport block, a code block, a codeword, etc. are actually mapped may be shorter than the TTI.

[0181] Note that when one slot or one mini-slot is called a TTI, one or more TTIs (i.e., one or more slots or one or more mini-slots) may be the minimum time unit of scheduling. Also, the number of slots (mini-slots) constituting the minimum time unit of the scheduling may be controlled.

[0182] A TTI having a time length of 1 ms may be called a normal TTI (TTI in LTE Rel.8 - 12), a normal TTI, a long TTI, a normal subframe, a normal subframe, a long subframe, a slot, etc. A TTI shorter than the normal TTI may be called a shortened TTI, a short TTI, a partial TTI (partial or fractional TTI), a shortened subframe, a short subframe, a mini-slot, a sub-slot, a slot, etc.

[0183] Note that a long TTI (e.g., a normal TTI, a subframe, etc.) may be read as a TTI having a time length exceeding 1 ms, or a short TTI (e.g., a shortened TTI, etc.) may be read as a TTI having a TTI length less than that of the long TTI and not less than 1 ms.

[0184] A resource block (RB) is a resource allocation unit in the time domain and the frequency domain, and in the frequency domain, it may include one or a plurality of consecutive subcarriers. The number of subcarriers included in the RB may be the same regardless of the numerology, for example, it may be 12. The number of subcarriers included in the RB may be determined based on the numerology.

[0185] Also, the time domain of the RB may include one or more symbols, and may be the length of 1 slot, 1 mini-slot, 1 sub-frame, or 1 TTI. 1 TTI, 1 sub-frame, etc. may each be composed of one or more resource blocks.

[0186] Note that one or more RBs may be referred to as physical resource blocks (PRBs), sub-carrier groups (SCGs), resource element groups (REGs), PRB pairs, RB pairs, etc.

[0187] Also, the resource block may be composed of one or more resource elements (REs). For example, 1 RE may be a radio resource area of 1 sub-carrier and 1 symbol.

[0188] The bandwidth part (BWP) (which may also be called a partial bandwidth, etc.) may represent a subset of consecutive common resource blocks (common RBs) for a certain numerology in a certain carrier. Here, the common RB may be specified by the index of the RB based on the common reference point of the carrier. The PRB is defined in a certain BWP and may be numbered within the BWP.

[0189] The BWP may include a BWP for UL (UL BWP) and a BWP for DL (DL BWP). For the terminal 20, one or more BWPs may be set within one carrier.

[0190] At least one of the set BWPs may be active, and the terminal 20 may not be assumed to transmit and receive a predetermined signal / channel outside the active BWP. Note that in the present disclosure, "cell", "carrier", etc. may be read as "BWP".

[0191] The structures such as the above-described radio frames, sub-frames, slots, mini-slots, and symbols are merely examples. For example, the number of sub-frames included in a radio frame, the number of slots per sub-frame or radio frame, the number of mini-slots included in a slot, the number of symbols and RBs included in a slot or mini-slot, the number of sub-carriers included in an RB, and the number of symbols within a TTI, symbol length, cyclic prefix (CP) length, etc. can be variously changed.

[0192] In the present disclosure, for example, when articles are added by translation, such as a, an, and the in English, the present disclosure may include that the nouns following these articles are in the plural form.

[0193] In the present disclosure, the term "A and B are different" may mean "A and B are different from each other". Note that this term may also mean "A and B are each different from C". Terms such as "separate", "coupled", etc. may also be interpreted in the same way as "different".

[0194] Each aspect / embodiment described in the present disclosure may be used alone, in combination, or switched and used during execution. Also, the notification of predetermined information (for example, the notification of "being X") is not limited to being explicitly performed, and may be performed implicitly (for example, without performing the notification of the predetermined information).

[0195] As described above in detail for the present disclosure, it is obvious to those skilled in the art that the present disclosure is not limited to the embodiments described in the present disclosure. The present disclosure can be implemented as modified and changed aspects without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the description of the present disclosure is for the purpose of illustrative explanation and has no restrictive meaning for the present disclosure.

Explanation of Reference Signs

[0196] 10 Base Station 10A Satellite 10B Gateway 10C Ground Base Station 10D CN 10E Aircraft 110 Transmitter 120 Receiver 130 Setting Unit 140 Control Unit 20 Terminal 210 Transmitter 220 Receiver 230 Setting Unit 240 Control Unit 30 Core Network 1001 Processor 1002 Memory Device 1003 Auxiliary Memory Device 1004 Communication Device 1005 Input Device 1006 Output Device 2001 Vehicle 2002 Driving Unit 2003 Steering Unit 2004 Accelerator Pedal 2005 Brake Pedal 2006 Shift Lever 2007 Front Wheel 2008 Rear Wheel 2009 Axle 2010 Electronic Control Unit 2012 Information Service Unit 2013 Communication Module 2021 Current Sensor 2022 Rotation Speed Sensor 2023 Air Pressure Sensor 2024 Vehicle Speed Sensor 2025 Acceleration Sensor 2026 Brake Pedal Sensor 2027 Shift Lever Sensor 2028 Object Detection Sensor 2029 Accelerator Pedal Sensor 2030 Driving Support System Unit 2031 Microprocessor 2032 Memory (ROM, RAM) 2033 Communication Port (IO Port)

Claims

1. A terminal that relays a satellite or an aircraft and communicates with a base station, comprising: a receiving unit that receives from the base station a parameter for updating a value of timing advance in communication with the base station; a control unit that, when the parameter is updated, divides an effective period of the parameter and changes a method of updating the value of the timing advance for each divided effective period. The terminal.

2. The value of the timing advance includes a first TA value updated by estimation based on the parameter received from the base station and a second TA value updated based on information received from the base station, and the control unit changes a method of updating the first TA value when the parameter is updated. The terminal according to Claim 1.

3. The value of the timing advance includes a first TA value updated by estimation based on the parameter received from the base station and a second TA value updated based on information received from the base station, and the control unit changes a method of updating the second TA value when the parameter is updated. The terminal according to Claim 1 or 2.

4. A communication method executed by a terminal that relays a satellite or an aircraft and communicates with a base station, comprising: receiving from the base station a parameter for updating a value of timing advance in communication with the base station; when the parameter is updated, dividing an effective period of the parameter and changing a method of updating the value of the timing advance for each divided effective period. The communication method.

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