Terminal and communication method

Abstract

This terminal comprises: a control unit that, in one TDD cycle in a time division duplex (TDD)-based non-terrestrial network (NTN), determines a TDD pattern which is started from an uplink symbol and which includes at least one of a downlink symbol and a flexible symbol following the uplink symbol; and a communication unit that executes communication to which the TDD pattern is applied.

Description

Terminal and communication method

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

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

[0003] Currently, non-terrestrial networks (NTNs) are being considered, which use non-terrestrial networks such as satellites to provide services to areas that cannot be covered by terrestrial 5G networks, mainly due to cost considerations (e.g., Non-Patent Documents 2 and 3).

[0004] 3GPP TS 38.300 V18.0.0 (2023-12) 3GPP TR 38.821 V16.2.0 (2023-03) Konishi et al., "A Study on Downlink Spectrum Sharing in HAPS Mobile Communication Systems," IEICE General Conference, B-17-1, 2020 3GPP TS 38.211 V18.1.0 (2023-12) 3GPP TSG RAN Meeting #102, RP-234078, December 2023 3GPP TS 38.101-5 V18.4.0 (2023-12) 3GPP TS 38.331 V18.0.0 (2023-12) 3GPP TS 38.213 V18.1.0 (2023-12) H. -W. Lee et al. al., "Interference Mitigation for Reverse Spectrum Sharing in B5G / 6G Satellite-Terrestrial Networks," in IEEE Transactions on Vehicular Technology, vol. 73, no. 3, pp. 4247-4263, March 2024

[0005] Currently, frequency division duplex (FDD) is commonly used as a duplexing method in NTN. On the other hand, time division duplex (TDD) can be used to easily accommodate asymmetric traffic loads on the uplink and downlink, and can configure both the uplink and downlink using only one band. However, when adopting TDD-based NTN, it is necessary to design the system taking into consideration interference between the TN system and the NTN system.

[0006] The present invention has been made in view of the above points, and has as its object to improve performance when TDD (Time division duplex) is applied in an NTN (Non-Terrestrial Network) environment.

[0007] According to the disclosed technology, there is provided a terminal having: a control unit that determines a TDD pattern that starts with an uplink symbol and includes at least one of a downlink symbol and a flexible symbol following the uplink symbol in one TDD (Time division duplex) period in a TDD-based NTN (Non-Terrestrial Network); and a communication unit that performs communication applying the TDD pattern.

[0008] According to the disclosed technology, it is possible to improve performance when applying TDD (Time division duplex) in an NTN (Non-Terrestrial Network) environment.

[0009] FIG. 1 is a diagram illustrating an example (1) of an NTN. FIG. 2 is a diagram illustrating an example (2) of an NTN. FIG. 3 is a diagram illustrating an example (3) of an NTN. FIG. 4 is a diagram illustrating an example (5) of an NTN. FIG. 5 is a diagram illustrating an example of receiving frame structure example (1). FIG. 6 is a diagram illustrating an example of receiving frame structure example (2). FIG. 7 is a diagram illustrating an example of receiving frame structure example (3). FIG. 8 is a diagram for explaining interference between an NTN and a TN. FIG. 9 is a diagram for explaining an example of performance in an NTN. FIG. 10 is a diagram for explaining an example of performance in a TN. FIG. 11 is a diagram illustrating an example (1) of a frame structure according to an embodiment of the present invention. FIG. 12 is a diagram illustrating an example (2) of a frame structure according to an embodiment of the present invention. FIG. 13 is a diagram illustrating an example (3) of a TDD period according to an embodiment of the present invention. FIG. 14 is a diagram illustrating an example (4) of a TDD period according to an embodiment of the present invention. FIG. 15 is a diagram illustrating an example (5) of a TDD period according to an embodiment of the present invention. FIG. 16 is a diagram illustrating an example of the functional configuration of a base station 10 according to an embodiment of the present invention. FIG. 17 is a diagram illustrating an example of the functional configuration of a terminal 20 according to an embodiment of the present invention. 1 is a diagram illustrating an example of a hardware configuration of a base station 10 or a terminal 20 according to an embodiment of the present invention.

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the embodiment described below is an example, and the embodiment to which the present invention is applied is not limited to the following embodiment.

[0011] In the operation of the wireless communication system according to the embodiment of the present invention, existing technology is used as appropriate. However, the existing technology is, for example, the existing LTE, but is not limited to the existing LTE. Furthermore, the term "LTE" used in this specification has a broad meaning including LTE-Advanced and systems subsequent to LTE-Advanced (e.g., NR), unless otherwise specified.

[0012] 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 similar signals, functions, etc. may be called by other names. In addition, the above-mentioned terms in NR correspond to NR-SS, NR-PSS, NR-SSS, NR-PBCH, NR-PRACH, NR-PDCCH, NR-PDSCH, NR-PUCCH, NR-PUSCH, etc. However, even if a signal is used in NR, it is not necessarily stated as "NR-".

[0013] Furthermore, in the embodiment of the present invention, the duplex method may be a time division duplex (TDD) method, a frequency division duplex (FDD) method, or another method (for example, flexible duplex, etc.).

[0014] Furthermore, in the embodiments of the present invention, "configuring" radio parameters etc. may mean that predetermined values ​​are pre-configured, or that radio parameters notified from the base station 10 or the terminal 20 are set.

[0015] FIG. 1 shows an example of an NTN (1). A Non-Terrestrial Network (NTN) uses non-terrestrial devices, such as satellites, to provide services to areas that cannot be covered by terrestrial 5G networks, primarily due to cost considerations. NTN can also provide more reliable services. For example, it is expected to be applied to IoT (Internet of Things), ships, buses, trains, and critical communications. NTN also has scalability through efficient multicast or broadcast.

[0016] As an example of an NTN, as shown in FIG. 1, a satellite 10A can retransmit signals transmitted from a terrestrial base station 10B to provide service to areas where terrestrial base stations are not located, such as mountainous regions.

[0017] 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 terminals 20. The physical resources of the wireless signal are defined in the time domain and the frequency domain, and 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 a synchronization signal and system information to the terminals 20. The synchronization signal is, for example, NR-PSS and NR-SSS. The system information is transmitted, for example, via NR-PBCH, and is also called broadcast information.

[0018] The base station 10 transmits control signals or data to the terminal 20 via DL (Downlink) and receives control signals or data from the terminal 20 via UL (Uplink). Both the base station 10 and the terminal 20 are capable of transmitting and receiving signals by performing beamforming. Furthermore, both the base station 10 and the terminal 20 are capable of applying MIMO (Multiple Input Multiple Output) communication to DL or UL. Furthermore, both the base station 10 and the terminal 20 may communicate via an SCell (Secondary Cell) and a PCell (Primary Cell) using CA (Carrier Aggregation).

[0019] 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, an M2M (Machine-to-Machine) communication module, etc. The terminal 20 receives control signals or data from the base station 10 via DL and transmits control signals or data to the base station 10 via UL, thereby utilizing various communication services provided by the wireless communication system.

[0020] Figure 2 shows an example of an NTN (2). The area of ​​each cell or beam in an NTN is much larger than that of a terrestrial network (TN). Figure 2 shows an example of an NTN configured with retransmission by satellite. 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.

[0021] 2, the difference in delay between UE 20A on the near side and 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 NTN is, for example, 3500 km in the case of GEO and 1000 km in the case of LEO.

[0022] FIG. 3 is a diagram showing an example (3) of an NTN. As shown in FIG. 3, an NTN is realized by a satellite in space or a flying object 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 every 88-127 minutes. For example, a HAPS (High Altitude Platform Station) may be a flying object located at an altitude of 8-50 km and performing circular flight.

[0023] As shown in Figure 3, GEO satellites, LEO satellites, and HAPS aircraft may be connected to ground stations (gNBs) via gateways. The service areas may be larger in the order of HAPS, LEO, and GEO.

[0024] For example, NTN can extend the coverage of 5G networks to unserved or served areas. Furthermore, for example, NTN can improve the continuity, availability, and reliability of services on ships, buses, trains, or other critical communications. The NTN may be signaled by transmitting dedicated parameters to the terminal 20, and the dedicated parameters may be, for example, parameters related to determining a timing advance (TA) based on information related to satellites or aircraft.

[0025] Figure 4 is a diagram showing an example of an NTN (4). Figure 4 shows an example of an NTN network architecture assumed in the case of transparent payload. As shown in Figure 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. An NR Uu is established between the gNB 10C and the terminal 20A or the VSAT 20B.

[0026] Furthermore, the assumed network architecture of the NTN may employ FDD or may be capable of TDD. Terrestrial cells may be fixed or mobile. The terminal 20 may have the capability to support the Global Navigation Satellite System (GNSS). For example, a power class 3 handheld device may be assumed in FR1. At least in FR2, a VSAT device may be assumed.

[0027] The NTN network architecture may also assume regenerative payloads. For example, gNB functionality may be mounted on a satellite or air vehicle. Alternatively, a gNB-DU may be mounted on a satellite or air vehicle, and a gNB-CU may be deployed as a ground station.

[0028] Figure 5 is a diagram showing an example of an NTN (5). As shown in Figure 5, the TA in the NTN includes a common TA corresponding to the distance from the satellite / HAPS 10A to the reference point (RP) in the feeder link, and a UE-specific TA corresponding to the distance from the satellite / HAPS 10A to the UE 20 in the service link. The TA of the service link is a UE-specific TA and varies depending on the location of the UE 20. Note that the feeder link includes a delay that is transparent to the user and corresponds to the distance from the reference point to the gNB / gateway 10B.

[0029] The reference point for UL synchronization may be determined by the network implementation. For example, the reference point may be any point on the satellite, gNB, GW, or feeder link. At the gNB or GW, the DL and UL time domains may be aligned to facilitate implementation. At the satellite, UE operations related to common TA may not be performed to reduce UE load.

[0030] The TA in NTN may be calculated, for example, as TTA = (NTA + NTA, UE-specific + NTA, common + NTA, offset) x TC (see Non-Patent Document 4).

[0031] NTA is 0 for PRACH and is notified by a TA command by MAC-CE (Medium Access Control - Control Element). NTA may be a closed-loop TA.

[0032] NTA,UE-specific is a TA specific to the UE. NTA,UE-specific may be a value estimated by the UE itself to compensate in advance for the delay of the service link. NTA,UE-specific is calculated based on the UE's position and the celestial orbit of the serving satellite.

[0033] NTA,common is a common TA controlled by the network. Hereinafter, NTA,common is also referred to as common TA. For example, if the reference point is a satellite, a value of 0 is supported. NTA,offset may be a fixed value used for TA calculation defined in the specification.

[0034] Downlink coverage extension in NTNs has been considered (see Non-Patent Document 5). Also, taking into account NTN deployment constraints such as payload power limitations, large satellite footprints, and limited feeder link bandwidth, the downlink coverage provides optimized performance, especially when addressing handset terminals (including smartphones with -5.5 dBi antenna gain).

[0035] DL coverage extension is needed to accommodate satellite payload constraints where limited power and limited feeder link bandwidth may not allow all beams to be activated at a given time with the "nominal" EIRP density (see 3GPP TS 2.0, section 6.1.1) per beam, while maximizing the number of beams that can be activated simultaneously and ensuring that all user terminals across the satellite footprint can be served, while ensuring that all satellite radio cells remain viable even when there is no traffic, allowing new users to join or preventing impact on end-user QoS.

[0036] DL coverage extension is a link level improvement to improve the link margin of selected physical channels to accommodate the reduction in EIRP in FR1-NTN, and link margin improvement for physical channels (e.g., PDSCH and PDCCH) can be considered without affecting the SSB design.

[0037] DL coverage extension also takes system level considerations into account to support efficient dynamic and flexible power sharing between beams or different beam patterns / sizes (i.e., wide or narrow) across the satellite footprint for FR1-NTN and FR2-NTN.

[0038] A beneficial downlink coverage extension is being considered that targets support for additional reference satellite payload parameters covering both Geostationary Orbit (GSO) and non-GSO (NGSO) constellations operating in FR1-NTN or FR2-NTN.

[0039] Assuming power sharing between satellite beams or different satellite beam patterns / sizes (i.e., wide or narrow) across the satellite footprint, additional reference satellite payload parameters are defined whereby satellite beams may not all be active simultaneously or may be active at less than the nominal EIRP density per satellite beam (see 3GPP TS 2.0, section 6.1.1) due to limited power and limited feeder link bandwidth.

[0040] Corresponding power sharing assumptions, required link-level and system-level assessment methods, and associated KPIs (Key Performance Indicators) for coverage assessment are defined to enable identification of physical channel / signal and system-level aspects requiring enhancement.

[0041] Consider and, if necessary, identify solutions including link-level extensions for FR1-NTN (e.g., for PDCCH, PDSCH) and / or system-level extensions for FR1-NTN and / or FR2-NTN to enable dynamic and flexible power sharing between satellite beams or between different satellite beam patterns / sizes (i.e., wide or narrow) across the satellite footprint.

[0042] For example, SSB channel enhancement is not considered. For example, in the case of a smartphone in FR1-NTN, the terminal antenna gain is assumed to be -5.5 dBi, the terminal is assumed to be a full-duplex terminal, and at least 2 Rx is considered in the terminal. For example, the NGSO that is given priority may be LEO Set-1 @ 600 km. For example, Rel-18 network energy saving technology should be considered as a baseline in system-level studies.

[0043] In NTN, SIB reception according to the existing NR specifications may not provide sufficient Block Error Rate (BLER) performance, so some extensions may be introduced to extend the coverage of SIB1. For example, coverage extensions of SIB1, SIB19, SIB25, SIB6, SIB7, or any other SIB may be introduced.

[0044] For example, according to the LLS results on PDSCH SIB1 coverage evaluation collected from different sources, it is as follows:

[0045] For PDSCH carrying SIB1 option 1 (payload size 800 bits), it is observed that the required SNR (Signal to noise ratio) is equal to -5.8 dB (14 sources) on average.

[0046] For PDSCH carrying SIB1 option 2 (payload size 1280 bits), it is observed that the required SNR is equal to -3.4 dB (12 sources) on average.

[0047] For parameters LEO 600 km, Set 1-1FR1 and 1-2FR1, 14 sources observed no coverage gap for PDSCH with SIB1 option 1. The coverage margin averages about 3.9 dB compared to a CNR (Carrier-to-Noise Ratio) of −1.9 dB. 12 sources observed no coverage gap for PDSCH with SIB1 option 2. The coverage margin averages about 1.5 dB compared to a CNR of −1.9 dB.

[0048] For parameters LEO 600 km, Set 1-3FR1, 11 sources observed a coverage gap for PDSCH with SIB1 option 1. Compared to a CNR of -9.9 dB, the coverage gap averages about 4.1 dB. One source observed no coverage gap for PDSCH with SIB1 option 1. Compared to a CNR of -9.9 dB, the coverage margin is 3.4 dB. Ten sources observed a coverage gap for PDSCH with SIB1 option 2. Compared to a CNR of -9.9 dB, the coverage gap averages about 6.5 dB.

[0049] Note that some results assumed the combination of SIB1 (SIB1 is repeated within 160 ms), and some results did not assume the combination of SIB1. Note that the above results were obtained independently of the performance of other channels or signals, and do not imply successful reception of other channels or signals before or after detection of the PDSCH carrying SIB1.

[0050] According to the LLS results on PDSCH SIB19 coverage evaluation collected from different sources, the following are found:

[0051] It is observed that the SNR required for the PDSCH carrying SIB19 is equal to -6.9 dB (14 sources) on average. With parameters LEO600 km, Set1-1FR1 and 1-2FR1, 12 sources observed no coverage gap for the PDSCH with SIB19. The coverage margin is about 4.2 dB on average compared to a CNR of -1.9 dB. With parameters LEO600 km, Set1-3FR1, 10 sources observed a coverage gap for the PDSCH with SIB19. The coverage gap is about 3.5 dB on average compared to a CNR of -9.9 dB.

[0052] Note that all the above results did not assume the combination of SIB19. Note that the above results were obtained independently of the performance of other channels or signals, and do not imply successful reception of other channels or signals before or after detection of the PDSCH carrying SIB19.

[0053] Currently, in NTNs (Non-Terrestrial Networks), FDD (Frequency division duplex) is generally used. For example, in 3GPP (registered trademark) NR NTN (see Non-Patent Document 6), the FDD operating band n256 is defined as UL 1980 MHz-2010 MHz and DL 2170 MHz-2200 MHz. Furthermore, the FDD operating band n255 is defined as UL 1626.5 MHz-1660.5 MHz and DL 1525 MHz-2200 MHz. Furthermore, the FDD operating band n254 is defined as UL 1610 MHz-1626.5 MHz and DL 2483.5 MHz-2500 MHz.

[0054] NR considers TDD mode as the primary duplexing mode, and only FDD mode is supported in some bands for FR1. The radio frame is fixed at 10 ms. The subframe is fixed at 1 ms. A slot is defined as 14 OFDM symbols. The numerology and CP length determine the time features of the OFDM symbol and the frequency features of the PRB.

[0055] The numerology defines μ = 0, 1, 2, 3, 4, 5, 6. The SCS and the duration of the symbol or slot vary with the numerology.

[0056] Regarding the CP length, the normal CP length is 14 symbols per slot, and the extended CP length is 12 symbols per slot. The extended CP length is only supported for 60 kHz SCS.

[0057] Quasi-static DL-UL slot allocation in NR is configured based on two higher layer parameters, tdd-UL-DL-ConfigurationCommon and / or tdd-UL-DL-ConfigurationDedicated (see non-patent document 7).

[0058] tdd-UL-DL-ConfigurationCommon is cell-specific signaling, and allows the settings described below.

[0059] The UL-DL transmission pattern determines the UL-DL transmission period, the number of DL slots, DL symbols, flexible symbols, UL symbols, and UL slots in each period. Up to two different UL-DL transmission patterns (Pattern 1 and Pattern 2) are supported simultaneously.

[0060] Reference SCS setting μ ｒｅｆ is the same for the two patterns. The reference SCS setting μ ｒｅｆ is less than or equal to the SCS configuration μ for any configured DL BWP or UL BWP.

[0061] In Pattern 1 / Pattern 2, the following parameters are set:

[0062] Slot setting periods P and P2, and different μ ｒｅｆ is the given μ ｒｅｆ , have different sets of values ​​for P and P2. The periods P and P2 must contain an integer number of slots. The minimum values ​​of P and P2 are greater than or equal to one slot length. The maximum values ​​of P and P2 are less than or equal to one frame length.

[0063] In each period, the OFDM symbols are set in the order of DL-flexible-UL. ｓｌｏｔｓ / d ｓｌｏｔｓ，２ is set to the number of DL slots according to the upper layer parameter nrofDownlinkSlots (see Non-Patent Document 7). ｓｌｏｔｓ / u ｓｌｏｔｓ，２ is set to the number of UL slots according to the upper layer parameter nrofUplinkSlots (see Non-Patent Document 7). ｓｙｍｂｏｌｓ / d ｓｙｍｂｏｌｓ，２ is set to the number of DL symbols according to the higher layer parameter nrofDownlinkSymbols (see Non-Patent Document 7). ｓｙｍｂｏｌｓ / u ｓｙｍｂｏｌｓ，２ is set to the number of UL symbols according to the upper layer parameter nrofUplinkSymbols (see Non-Patent Document 7).

[0064] d ｓｌｏｔｓ / d ｓｌｏｔｓ，２ and u ｓｌｏｔｓ / u ｓｌｏｔｓ，２ The values ​​of are 0, 1, 2, ..., maxNorfslots. maxNorfslots is 320. d ｓｙｍｂｏｌｓ / d ｓｙｍｂｏｌｓ，２ and u ｓｙｍｂｏｌ s / u ｓｙｍｂｏｌｓ，２ The values ​​of maxNorfslymbols are 0, 1, 2, ..., maxNorfslymbols-1. maxNorfslymbols is 14 for normal CP and 12 for extended CP.

[0065] When the UE configures two UL-DL transmission patterns, it configures the slot format for each slot over a first number of slots as indicated by pattern 1 and the slot format for each slot over a second number of slots as indicated by pattern 2.

[0066] The slot setting period msec of (P+P2) is the first S=P×2^μ ｒｅｆ slots and the second S2 = P2 × 2^μ ｒｅｆ In the following, the description corresponding to P will be written before / , and the description corresponding to P2 will be written after / .

[0067] The S and S2 slots are the first d ｓｌｏｔｓ / d ｓｌｏｔｓ，２ DL slot and last u ｓｌｏｔｓ / u ｓｌｏｔｓ，２ DL symbol d ｓｙｍｂｏｌｓ / d ｓｙｍｂｏｌｓ，２ is the first DL slot d ｓｌｏｔｓ / d ｓｌｏｔｓ，２ It is placed after the UL symbol u ｓｙｍｂｏｌｓ / u ｓｙｍｂｏｌｓ，２ is the last UL slot u ｓｌｏｔｓ / u ｓｌｏｔｓ，２ The flexible symbol (S-d ｓｌｏｔｓ -u ｓｌｏｔｓ ) x N ｓｙｍｂ ｓｌｏｔ -d ｓｙｍｂｏｌｓ -u ｓｙｍｂｏｌｓ / (S2-d ｓｌｏｔｓ , 2-u ｓｌｏｔｓ，２ ) x N ｓｙｍｂ ｓｌｏｔ -d ｓｙｍｂｏｌｓ，２ -u ｓｙｍｂｏｌｓ，２ is included in the S / S2 slot.

[0068] The UE assumes that P or P+P2 is evenly divisible by 20 ms. The UE assumes that the first symbol of every 20 / P or 20 / (P+P2) period is the first symbol in an even frame.

[0069] tdd-UL-DL-ConfigurationDedicated is UE-specific signaling and can be configured as described below.

[0070] If the UE is also configured with tdd-UL-DL-ConfigurationDedicated, the parameter tdd-UL-DL-ConfigurationDedicated overrides only the flexible symbols per slot of the number of slots configured by tdd-UL-DL-ConfigurationCommon.

[0071] tdd-UL-DL-ConfigurationDedicated sets: - a set of slot configurations given by slotSpecificConfigurationsToAddModList - for each slot configuration from the set of slot configurations: - the slot index of the slot given by slotIndex - the set of symbols of the slot given by symbols If symbols = allDownlink, all symbols in the slot are downlink. If symbols = allUplink, all symbols in the slot are uplink. If symbols = explicit, nrofDownlinkSymbols gives the number of the first downlink symbols in the slot and nrofUplinkSymbols gives the number of the last uplink symbols in the slot. If nrofDownlinkSymbols is not provided, there is no first downlink symbol in the slot and if nrofUplinkSymbols is not provided, there is no last uplink symbol in the slot. The remaining symbols in the slot are flexible.

[0072] The order of the OFDM symbols is "downlink-flexible-uplink".

[0073] In NR, dynamic slot format indication (SFI) is supported. Based on the SFI transmitted from the BS, the UE can determine its own TDD UL-DL transmission pattern. The order of the OFDM symbols is "downlink-flexible-uplink." Table 1 shows an example of a slot format in NR (see Non-Patent Document 8).

[0074]

[0075] 6 is a diagram showing an example of receiving the frame structure example (1). Fig. 6 shows an example of configuration using tdd-UL-DL-ConfigurationCommon. The number of DL slots, number of DL symbols, number of flexible symbols or slots, number of UL symbols, and number of UL slots are set. One period may be, for example, 0.5 ms, 0.625 ms, 1.25 ms, 1 ms, 2 ms, 5 ms, or 10 ms.

[0076] Fig. 7 is a diagram showing an example of receiving the frame structure example (2). Fig. 7 shows an example of a configuration using tdd-UL-DL-ConfigurationDedicated. In Fig. 7, allDownlink, explicit, and allUplink are set, and the number of DL symbols, the number of flexible symbols, and the number of UL symbols are specified.

[0077] Fig. 8 is a diagram showing an example of receiving the frame structure example (3). Fig. 8 shows an example of setting by SFI. Fig. 8 shows an example in which 45 is notified as the SFI index. According to Table 1, SFI index 45 has a slot configuration of DDDDDDDFFUUUUUUU. D indicates a DL symbol, F indicates a flexible symbol, and U indicates a UL symbol.

[0078] Traditional FDD-based satellite network communications are used for television broadcasting, short message services, etc. Mobile phone Direct to Satellite Service (D2SS) is a hot topic in the industry. Currently, more and more satellite operators and terrestrial mobile operators are cooperating to realize D2SS.

[0079] Meanwhile, among the main candidate spectrum bands for achieving integration between TN and NTN in 6G, the main duplex mode for TN systems is TDD mode. The advantages of TDD-based NTN for D2SS include:

[0080] The abundance of mobile applications leads to asymmetric UL and DL traffic loads for D2SS. The FDD mode, with its symmetric UL / DL spectrum, results in wasted spectrum resources. The TDD mode can flexibly adjust the configuration of UL and DL time slots according to the UL and DL traffic loads. As spectrum resource limitations, the FDD mode requires a pair of UL and DL spectrums. Meanwhile, the TDD mode only requires one spectrum band for both UL and DL. Regarding the hardware cost of a mobile phone, the FDD mode requires two sets of antennas, one set for the transmitter and the other for the receiver, resulting in high hardware costs. Meanwhile, the TDD mode can be designed based on one set of antennas for both the transmitter and the receiver via a duplexer or switch circuit to reduce costs.

[0081] In a TDD-based NTN, the interference between the TN system and the NTN system needs to be considered.

[0082] FIG. 9 is a diagram for explaining interference between NTN and TN. As shown in FIG. 9, NTN-UE may be subject to interference from signals related to TN-UE, and TN-UE may be subject to interference from signals related to NTN-UE. In the example of FIG. 9, TN-DL and NTN-UL are operated in band F1, and TN-UL and NTN-DL are operated in band F2. In TN and NTN, interference can be reduced by reversing UL and DL in a certain band (see Non-Patent Document 9).

[0083] Fig. 10 is a diagram for explaining an example of performance in an NTN. In Fig. 10, "no sharing" indicates no bandwidth sharing, "normal" indicates that both the NTN and the TN operate UL or DL ​​in a certain band, and "reverse" indicates that when one of the NTN and the TN operates UL in a certain band, the other operates DL, and when one operates DL, the other operates UL.

[0084] As shown in Fig. 10, although the SINR varies depending on the elevation angle, the DL reverse has a gain of about 5 dB compared to the DL normal when the elevation angle is 60 degrees. Also, as shown in Fig. 10, although the SINR varies depending on the elevation angle, the UL reverse has a gain of about 10 dB compared to the UL normal when the elevation angle is 50 degrees.

[0085] Fig. 11 is a diagram for explaining an example of performance in a TN. In Fig. 11, "no sharing" indicates no bandwidth sharing, "normal" indicates that both the NTN and the TN operate UL or DL ​​in a certain band, and "reverse" indicates that when one of the NTN and the TN operates UL in a certain band, the other operates DL, and when one operates DL, the other operates UL.

[0086] As shown in Fig. 11, although the SINR varies depending on the elevation angle, the DL reverse has a gain of about 0.4 dB compared to the DL normal when the elevation angle is 45 degrees. Also, as shown in Fig. 11, although the SINR varies depending on the elevation angle, the UL reverse has a gain of about 1.3 dB compared to the UL normal when the elevation angle is 40 degrees.

[0087] As mentioned above, by reversing the DL and UL and sharing the spectrum, performance can be improved in both the NTN and TN.

[0088] Scenarios and assumptions include coexistence or spectrum sharing between TN and NTN. Full or partial reverse link pairing between TDD-TN and TDD-NTN may be supported for interference cancellation. Each UE may access only the TN system or only the NTN system on the same carrier frequency.

[0089] FDD-TN or NTN with an OFDM symbol order of "downlink-flexible-uplink" (e.g., DDDSU...), and TDD-TN are supported in NR. Also, in the TDD NTN frame structure, TDD-NTN with an OFDM symbol order of "downlink-flexible-uplink" may be supported. Note that "D" may refer to a downlink slot, "U" may refer to an uplink slot, and "S" may refer to a slot that includes downlink, uplink, or a mixture of downlink and uplink.

[0090] The TDD periodicity should be aligned for TDD-TN and / or TDD-NTN. TDD BSs and UEs located in the same geographic area should be assigned "D" or "U" simultaneously.

[0091] On the other hand, by reversing the DL and UL and sharing the bandwidth as described above, we will now explain how to adjust the slot configurations of TDD-NTN and TDD-TN to achieve full or partial reverse link pairing, which can improve performance in the NTN and TN, respectively.

[0092] Operation 1) In one TDD period, a configuration may be possible in which the UL starts first and the DL follows. For example, this may be UUDSU. The UE may perform communication by applying the determined TDD pattern.

[0093] Operation 1-1) Upper layer parameters that are the OFDM symbol order of "UL-DL-flexible-UL" in each TDD period may be defined. The parameter format may be as follows:

[0094] 12 is a diagram showing an example (1) of a frame structure according to an embodiment of the present invention, in which a period P includes K slots.

[0095] The first UL portion and the second UL portion may be configured by separate parameters. For example, the first UL portion is configured by nrofFirstUplinkSlots (number of slots u ｓｌｏｔｓ), and nrofFirstUplinkSymbols (number of symbols u ｓｙｍｂｏｌｓ For example, the second UL portion may be set based on nrofLastUplinkSlots (number of slots u2 ｓｌｏｔｓ ), and nrofLastUplinkSymbols (number of symbols u2 ｓｙｍｂｏｌｓ ) may be set based on the ｓｙｍｂｏｌｓ is u2 ｓｙｍｂｏｌｓ In FIG. ｓｙｍｂｏｌｓ ) is not shown. ｓｙｍｂｏｌｓ is u1 ｓｌｏｔｓ These parameters may also be common to the TDD pattern starting from the DL.

[0096] u1 ｓｌｏｔｓ and u2 ｓｌｏｔｓ The value of u1 may range from a minimum of 0 to a maximum of the number of available slots in the maximum period. ｓｌｏｔｓ +u2 ｓｌｏｔｓ may be limited to be equal to or less than the maximum value.

[0097] u1 ｓｙｍｂｏｌｓ and u2 ｓｙｍｂｏｌｓ The value of u1 may range from a minimum of 0 to a maximum of the number of symbols available per slot minus 1. ｓｙｍｂｏｌｓ +u2 ｓｙｍｂｏｌｓ may be limited to be equal to or less than the maximum value, or the limit may not be applied.

[0098] The DL part is nrofDownlinkSlots (number of slots d ｓｌｏｔｓ ), and nrofDownlinkSymbols (number of symbols d ｓｙｍｂｏｌｓ ) in FIG. ｓｌｏｔｓ , d ｓｙｍｂｏｌｓ Corresponds to.

[0099] In addition, d ｓｌｏｔｓ , u1 ｓｙｍｂｏｌｓmay be 0. Note that the above upper layer parameters may be configured in N patterns. N may be 2 or more. Note that the parameter for the number of slots may not be configured. For example, the parameter for the number of slots may not be configured in the UE-specific parameters.

[0100] Cell-wide parameters and / or UE-specific parameters may be configured, for example, UE-specific parameters may be restricted, or cell-wide parameters may be substituted for cell-specific parameters.

[0101] If the cell-common parameters are configured with a TDD pattern starting with U without an explicit D part such as "UUSSU", the UE-specific parameters configured with the TDD pattern starting with U may override the flexible part with a TDD pattern determined based on the cell-specific parameters. In other cases, the UE-specific parameters may be configured with only the TDD pattern starting with D. That is, in this case, the UE may not assume a UE-specific configuration of the TDD pattern starting with U.

[0102] The TDD pattern starting with D and the TDD pattern starting with U may be set by a common or individual parameter set.

[0103] In individual cases, the following may be configured: If a parameter set for a TDD pattern starting from U is configured, the UE may determine a TDD pattern starting from U. Otherwise, the terminal may determine a TDD pattern starting from D. The parameter set for a TDD pattern starting from U may be configured only for TN UEs or NTN UEs, or may be configured for TN UEs and NTN UEs. The UE-specific parameter set for a TDD pattern starting from U may include, for each slot, parameters indicating all downlinks in the slot, or parameters indicating all uplinks in the slot, or parameters indicating a TDD pattern starting from U in the slot.

[0104] For a TDD pattern starting at D versus a TDD pattern starting at U, for example, assume that the UE receives either parameters for a TDD pattern starting at D or parameters for a TDD pattern starting at U. If the former is received, the terminal determines the TDD pattern starting at D. If the latter is received, the UE determines the TDD pattern starting at U.

[0105] For example, the UE is ｓｌｏｔｓ , u1 ｓｙｍｂｏｌｓ , u2 ｓｌｏｔｓ , u2 ｓｙｍｂｏｌｓ , d ｓｌｏｔｓ , d ｓｙｍｂｏｌｓ Assume that the parameter u1 is always received. ｓｌｏｔｓ =u1 ｓｙｍｂｏｌｓ = 0, the terminal determines a TDD pattern starting from D. Otherwise, the terminal determines a TDD pattern starting from U. Note that the candidate values ​​of the parameters of the TDD pattern starting from "U" may be the same as or different from the candidate values ​​of the parameters of the TDD pattern starting from "D".

[0106] Figure 13 shows an example (2) of a frame structure according to an embodiment of the present invention. Figure 13 shows an example of a TDD pattern according to the upper layer parameter tdd-UL-DL-ConfigurationCommon, which may be applied to both TN and NTN. As shown in Figure 13, only pattern 1 may be repeated.

[0107] The TDD pattern shown in FIG. 13 may also be configured by the higher layer parameter tdd-UL-DL-ConfigurationCommon-extra.

[0108] Figure 14 shows an example (3) of a frame structure according to an embodiment of the present invention. Figure 14 shows an example of a TDD pattern according to the upper layer parameter tdd-UL-DL-ConfigurationCommon, which may be applied to both TN and NTN. As shown in Figure 14, Pattern 1 and Pattern 2 may be set.

[0109] The TDD pattern shown in FIG. 14 may also be configured by the higher layer parameter tdd-UL-DL-ConfigurationCommon-extra.

[0110] Operation 1-2) A slot format of "uplink-downlink-flexible-uplink" OFDM symbol order in each period may be defined. Note that "Alt" may be replaced with an alternative.

[0111] "Slot format" can include the following: Slot format starts with uplink Alt. 1: downlink or flexible Alt. 2: downlink followed by flexible Alt. 3: downlink followed by flexible followed by uplink

[0112] The slot format of the table in operation 1-3-1), operation 1-3-2) or operation 1-3-3) described below may be used.

[0113] Operation) 1-3-1: Define a new slot format table.

[0114] Option 1: Define a unified new slot format table that includes all alternatives. Option 1-1: The unified new slot format table is common to both TN and NTN. Some entries are available only to TN or NTN. Option 1-2: Define separate TN-specific and NTN-specific unified slot format tables.

[0115] Option 2: Define different new slot format tables for the different Alts above. For example, one new table may be defined for each Alt (e.g., one table only for Alt. 1), and / or one new table for the two options (e.g., one table for both Alt. 1 and Alt. 2). Option 2-1: The different new slot format tables are common to both TN and NTN, but some entries are available only to either TN or NTN. Option 2-2: Define different TN-specific and NTN-specific new slot format tables separately.

[0116] Action 1-3-2) Add a new entry to the legacy slot format table.

[0117] Option 1: Add a new entry with all Alts in the same slot format table. Option 2: Add a new entry with different Alts in a different slot format table.

[0118] The newly added entries may be common to both TN and NTN, and / or may be TN-specific and / or NTN-specific.

[0119] Action 1-3-3) Replace some entries in the legacy slot format table.

[0120] Option 1: A replaced entry containing all Alts in the same slot format table. Option 2: A replaced entry containing different Alts in different slot format tables.

[0121] The replaced entries may be common to both TN and NTN, and / or may be TN-specific and / or NTN-specific.

[0122] Table 2 shows an example of a slot format table for operation 1-3-1) option 1-1.

[0123]

[0124] For example, in Table 2, indexes 13 through 18 may apply to TN only.

[0125] Table 3 shows an example of a slot format table for operation 1-3-1) option 1-2.

[0126]

[0127] For example, the slot format table in Table 3 may apply to TN only.

[0128] Table 4 shows an example of a slot format table for operation 1-3-1) option 1-2.

[0129]

[0130] For example, the slot format table in Table 4 may apply only to NTNs.

[0131] Table 5 shows an example of a slot format table for operation 1-3-2) option 1.

[0132]

[0133] For example, as shown in Table 5, new entries from index 16 to index 29 may be added to the legacy slot format table.

[0134] Table 6 shows an example of a slot format table for operation 1-3-2) option 2.

[0135]

[0136] For example, new entries from index 17 to index 24 may be added to the legacy slot format table as shown in Table 6. Table 6 is also a slot format table including Alt. 1 and Alt. 2.

[0137] Table 7 shows an example of a slot format table for operation 1-3-2) option 2.

[0138]

[0139] For example, new entries from index 17 to index 21 may be added to the legacy slot format table as shown in Table 7. Table 7 is also a slot format table including Alt. 3.

[0140] Table 8 shows an example of a slot format table for operation 1-3-3) option 1.

[0141]

[0142] For example, as shown in Table 8, in the legacy slot format table, entries from index 16 to index 29 may be replaced with new entries.

[0143] Table 9 shows an example of a slot format table for operation 1-3-3) option 2.

[0144]

[0145] For example, in the legacy slot format table, entries from index 16 to index 24 may be replaced with new entries, as shown in Table 9. The slot format table shown in Table 9 starts with UL followed by DL or flexible, or DL ​​followed by flexible.

[0146] Table 10 shows an example of a slot format table for operation 1-3-3) option 2.

[0147]

[0148] For example, in the legacy slot format table, entries from index 16 to index 21 may be replaced with new entries as shown in Table 10. The slot format table shown in Table 10 starts with UL, followed by DL, flexible, and UL in that order.

[0149] Proposal 2) The start timing of the TDD cycle can be different or changed between cells, for example, TDD-TN and TDD-NTN, as shown in the following figure.

[0150] 15 is a diagram showing an example (1) of a TDD cycle according to an embodiment of the present invention. As shown in FIG. 15, in a TN cell, the TDD cycle may start from slot n, and in an NTN cell, the TDD cycle may start from slot n+3.

[0151] Operation 2-1) The start timing of the TDD cycle in TDD-NTN may be later than the start timing in TDD-TN.

[0152] Action 2-1-1) The value of the delayed start timing may be determined based on the first UL slot in a TDD period in TDD-TN. The start timing of the TDD period in TDD-NTN may be aligned with the first UL slot of the TDD period in TDD-TN.

[0153] FIG. 16 is a diagram showing an example (2) of a TDD cycle in an embodiment of the present invention. FIG. 16 is an example of operation 2-1-1). As shown in FIG. 16, the start timing of a TDD cycle in TDD-NTN is the first UL slot of the TDD cycle in TDD-TN. In the example of FIG. 16, slot n+4 is the start timing of the TDD cycle in TDD-NTN.

[0154] Operation 2-1-2) The value of the delayed start timing may be determined by the first UL slot in a TDD period in the TDD-NTN and the TDD period in the TDD-TN. The start timing of the TDD period in the TDD-NTN may be determined so that the first UL slot in a TDD period in the TDD-NTN aligns with the first DL slot of the next TDD period in the TDD-TN.

[0155] FIG. 17 is a diagram showing an example (3) of a TDD cycle in an embodiment of the present invention. FIG. 17 is an example of operation 2-1-2). As shown in FIG. 17, the start timing of a TDD cycle in a TDD-NTN may be determined so that the first UL slot in a TDD cycle in the TDD-NTN aligns with the first DL slot of the next TDD cycle in the TDD-TN. In the example of FIG. 17, the alignment occurs at slot n+5, and slot n+3 is the start timing of the TDD cycle in the TDD-NTN.

[0156] Operation 2-2) The start timing of the TDD cycle of TDD-TN may be later than that of TDD-NTN.

[0157] Action 2-2-1) The value of the delayed start timing may be determined by the first UL slot of a TDD period in TDD-NTN. The start timing of a TDD period in TDD-TN may be aligned with the first UL slot in a TDD period in TDD-NTN.

[0158] FIG. 18 is a diagram showing an example (4) of a TDD cycle in an embodiment of the present invention. FIG. 18 is an example of operation 2-2-1). As shown in FIG. 18, the start timing of a TDD cycle in TDD-TN is the first UL slot of the TDD cycle in TDD-NTN. In the example of FIG. 18, slot n+2 is the start timing of a TDD cycle in TDD-NTN.

[0159] Action 2-2-2) The value of the delayed start timing may be determined by the first UL slot of a TDD period in TDD-TN and the TDD period in TDD-NTN. The start timing of the TDD period in TDD-TN may be determined so that the first UL slot in a TDD period in TDD-TN aligns with the first DL slot in the next TDD period in TDD-NTN.

[0160] FIG. 19 is a diagram showing an example (5) of a TDD cycle in an embodiment of the present invention. FIG. 19 is an example of operation 2-2-2). As shown in FIG. 19, the start timing of a TDD cycle in TDD-TN may be determined so that the first UL slot in a TDD cycle in TDD-TN aligns with the first DL slot of the next TDD cycle in TDD-NTN. In the example of FIG. 19, the alignment occurs at slot n+5, and slot n+1 is the start timing of the TDD cycle in TDD-TN.

[0161] Operation 2-3) The start timing of the TDD cycle may be signaled and / or set as follows.

[0162] Proposal 2-3-1) The starting timing offset for either type of cell (TN cell or NTN cell) may be predefined in the specification or configured by new signaling, which may be higher layer or physical layer signaling, such as RRC signaling, MAC-CE, UCI, or DCI.

[0163] For example, the starting timing offset of the NTN cell as described in operation 2-1) may be predefined in the specification, or a new signaling StartingTimeOffsetCell may be defined in the specification.

[0164] If StartingTimeOffsetCell=TN, the starting timing offset is for the TN cell.

[0165] If StartingTimeOffsetCell=NTN, the starting timing offset is for the NTN cell.

[0166] If the signaling is not configured, the starting timing offset does not need to be configured for all cells.

[0167] Action 2-3-2) The value of the start timing offset of the TDD cycle may be predefined in the specification or may be set by new signaling. The new signaling may be signaling of a higher layer or a physical layer, such as RRC signaling, MAC-CE, UCI, or DCI.

[0168] For example, the value of the Starting Timing Offset may be defined in the specification as a default value of "3 slots". Alternatively, it may be configured using new signaling StartingTimeOffsetValue defined in the specification. The value of the Starting Timing Offset is configured by this signaling. If this signaling is not configured, the timing offset value may be 0. All cells that consider the Starting Timing Offset may be configured with the same offset value, or different cells that consider the Starting Timing Offset may be configured with different offset values.

[0169] The following UE capabilities may be defined:

[0170] Define a UE capability indicating whether the UE supports cell-specific and UE-specific TDD UL-DL transmission pattern configuration for TN and / or NTN. Define a UE capability indicating whether the UE supports slot format tables for TN and / or NTN. Define a UE capability indicating whether the UE supports different start timings and signaling defined in action 2) for TN and / or NTN. UE capabilities may be the same or different for different frequency bands. UE capabilities may be the same or different for TN and NTN.

[0171] The following capabilities may be defined for TN BSs and NTN HAPSs / satellites:

[0172] Define the capabilities of the TN BS and NTN HAPSs / satellites, indicating whether they support the cell-specific and UE-specific TDD UL-DL transmission pattern configuration defined in action 1). Define the capabilities of the TN BS and NTN HAPSs / satellites, indicating whether they support the slot format table defined in action 1). Define the capabilities of the TN BS and NTN HAPSs / satellites, indicating whether they support the different start timing and signaling defined in action 2). The capabilities of the TN BS and NTN HAPSs / satellites may be the same or different in different frequency bands.

[0173] According to the above-described embodiment, the terminal 20 can support a TDD pattern starting from the UL and extend the slot format, thereby reducing interference in the NTN environment and the TN environment.

[0174] That is, it is possible to improve performance when applying TDD (Time division duplex) in an NTN (Non-Terrestrial Network) environment.

[0175] (Device Configuration) Next, a functional configuration example of the base station 10 and the terminal 20 that execute the processes and operations described above will be described. The base station 10 and the terminal 20 include functions for implementing the above-described embodiments. However, the base station 10 and the terminal 20 may each include only a part of the functions of the embodiments.

[0176] <Base Station 10> Figure 20 is a diagram showing an example of the functional configuration of the base station 10 in an embodiment of the present invention. As shown in Figure 20, the base station 10 has a transmitting unit 110, a receiving unit 120, a setting unit 130, and a control unit 140. The functional configuration shown in Figure 20 is merely an example. The names of the functional divisions and functional units may be any as long as they can perform the operations related to the embodiment of the present invention.

[0177] The transmitter 110 has a function of generating a signal to be transmitted to the terminal 20 side and transmitting the signal wirelessly. The transmitter 110 also transmits inter-network node messages to other network nodes. The receiver 120 has a function of receiving various signals transmitted from the terminal 20 and acquiring, for example, information of higher layers from the received signals. The transmitter 110 also has a function of transmitting NR-PSS, NR-SSS, NR-PBCH, DL / UL control signals, etc. to the terminal 20. The receiver 120 also receives inter-network node messages from other network nodes.

[0178] The setting unit 130 stores preset setting information and various setting information to be transmitted to the terminal 20. The content of the setting information is, for example, information related to communication in the NTN.

[0179] As described in the embodiments, the control unit 140 controls communication in the NTN. The control unit 140 also controls communication with the terminal 20 based on a UE capability report regarding radio parameters received from the terminal 20. A functional unit related to signal transmission in the control unit 140 may be included in the transmitting unit 110, and a functional unit related to signal reception in the control unit 140 may be included in the receiving unit 120.

[0180] <Terminal 20> Fig. 21 is a diagram showing an example of the functional configuration of terminal 20 in an embodiment of the present invention. As shown in Fig. 21, terminal 20 has a transmitting unit 210, a receiving unit 220, a setting unit 230, and a control unit 240. The functional configuration shown in Fig. 21 is merely an example. The names of the functional divisions and functional units may be any as long as they can execute the operations related to the embodiment of the present invention.

[0181] The transmitter 210 creates a transmission signal from transmission data and transmits the transmission signal wirelessly. The receiver 220 wirelessly receives various signals and acquires higher layer signals from the received physical layer signals. The receiver 220 also has a function of receiving NR-PSS, NR-SSS, NR-PBCH, DL / UL / SL control signals, and the like transmitted from the base station 10. For example, the transmitter 210 transmits a PSCCH (Physical Sidelink Control Channel), a PSSCH (Physical Sidelink Shared Channel), a PSDCH (Physical Sidelink Discovery Channel), a PSBCH (Physical Sidelink Broadcast Channel), and the like to another terminal 20 as D2D communication, and the receiver 120 receives the PSCCH, PSSCH, PSDCH, or PSBCH, and the like, from the other terminal 20.

[0182] The setting unit 230 stores various setting information received from the base station 10 by the receiving unit 220. The setting unit 230 also stores setting information that is set in advance. The content of the setting information is, for example, information related to communication in the NTN.

[0183] As described in the embodiments, the control unit 240 controls communications in the NTN. The signal transmission functional unit in the control unit 240 may be included in the transmitting unit 210, and the signal reception functional unit in the control unit 240 may be included in the receiving unit 220.

[0184] (Hardware Configuration) The block diagrams (FIGS. 20 and 21) used to explain the above embodiments show functional blocks. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method for realizing each functional block is not particularly limited. That is, each functional block may be realized using a single device that is physically or logically coupled, or may be realized using two or more physically or logically separated devices that are directly or indirectly connected (for example, using wires, wirelessly, etc.) and these multiple devices. The functional block may be realized by combining software with the single device or the multiple devices.

[0185] Functions include, but are not limited to, judgment, determination, assessment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, consideration, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs transmission is called a transmitting unit or transmitter. As mentioned above, there are no particular limitations on how these functions are implemented.

[0186] For example, the base station 10, the terminal 20, etc. according to an embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Fig. 22 is a diagram illustrating an example of the hardware configuration of the base station 10 and the terminal 20 according to an embodiment of the present disclosure. The base station 10 and the terminal 20 described above may be physically 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, etc.

[0187] In the following description, the term "apparatus" can be interpreted as a circuit, a device, a unit, etc. The hardware configuration of the base station 10 and the terminal 20 may be configured to include one or more of the apparatuses shown in the drawings, or may be configured to exclude some of the apparatuses.

[0188] Each function in the base station 10 and the terminal 20 is realized by loading specified software (programs) onto hardware such as the processor 1001, the memory device 1002, etc., so that the processor 1001 performs calculations, controls communication by the communication device 1004, and controls at least one of reading and writing data in the memory device 1002 and the auxiliary memory device 1003.

[0189] The processor 1001 controls the entire computer by running, for example, an operating system. The processor 1001 may be configured as a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, a register, etc. For example, the above-mentioned control unit 140, control unit 240, etc. may be realized by the processor 1001.

[0190] Furthermore, the processor 1001 reads programs (program codes), software modules, 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 in accordance with the programs. The programs used are those that cause a computer to execute at least some of the operations described in the above-described embodiments. For example, the control unit 140 of the base station 10 shown in FIG. 20 may be implemented by a control program stored in the storage device 1002 and running on the processor 1001. Furthermore, for example, the control unit 240 of the terminal 20 shown in FIG. 21 may be implemented by a control program stored in the storage device 1002 and running on the processor 1001. While the above-described various processes have been described as being executed by one processor 1001, they may also be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented by one or more chips. The programs may also be transmitted from a network via a telecommunications line.

[0191] The storage device 1002 is a computer-readable recording medium and may be configured, for example, by at least one of a read-only memory (ROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a random access memory (RAM), etc. The storage device 1002 may also be called a register, a cache, a main memory, etc. The storage device 1002 can store executable programs (program codes), software modules, etc. for implementing a communication method according to an embodiment of the present disclosure.

[0192] The secondary storage device 1003 is a computer-readable recording medium, and may be, 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 (e.g., a compact disk, a digital versatile disk, a Blu-ray (registered trademark) disk), a smart card, a flash memory (e.g., a card, a stick, a key drive), a floppy (registered trademark) disk, a magnetic strip, etc. The above-mentioned 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 secondary storage device 1003.

[0193] The communication device 1004 is hardware (transmission / reception device) for communicating 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 a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. to realize at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, a transmission / reception antenna, an amplifier unit, a transmission / reception unit, a transmission path interface, etc. may be realized by the communication device 1004. The transmission / reception unit may be implemented as a transmission unit and a reception unit that are physically or logically separated.

[0194] The input device 1005 is an input device (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives input from the outside. The output device 1006 is an output device (e.g., a display, a speaker, an LED lamp, etc.) that outputs to the outside. Note that the input device 1005 and the output device 1006 may be integrated into one device (e.g., a touch panel).

[0195] Furthermore, 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 between each device.

[0196] Furthermore, 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), or a field programmable gate array (FPGA), and some or all of the functional blocks may be realized by the hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

[0197] Fig. 23 shows an example configuration of a vehicle 2001. As shown in Fig. 23, 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 may be applied to the communication module 2013, for example.

[0198] The drive unit 2002 is configured, for example, by 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 the operation of the steering wheel operated by the user.

[0199] The electronic control unit 2010 is composed of a microprocessor 2031, a memory (ROM, RAM) 2032, and a communication port (IO port) 2033. Signals are input to the electronic control unit 2010 from various sensors 2021 to 2029 provided in the vehicle 2001. The electronic control unit 2010 may also be called an ECU (Electronic Control Unit).

[0200] The 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 front or rear wheel rotation speed signal obtained by a rotation speed sensor 2022, a front or rear wheel air pressure signal 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, an accelerator pedal depression amount signal obtained by an accelerator pedal sensor 2029, a brake pedal depression amount signal obtained by a brake pedal sensor 2026, a shift lever operation signal obtained by a shift lever sensor 2027, and a detection signal for detecting obstacles, vehicles, pedestrians, etc. obtained by an object detection sensor 2028.

[0201] The information service unit 2012 is composed of various devices, such as a car navigation system, an audio system, speakers, a television, and a radio, for providing (outputting) various types of information, such as driving information, traffic information, and entertainment information, and one or more ECUs for controlling these devices. The information service unit 2012 uses information acquired from external devices via the communication module 2013 or the like to provide various types of multimedia information and multimedia services to the occupants of the vehicle 2001. The information service unit 2012 may include input devices (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, a touch panel, etc.) that accept input from the outside, and may also include output devices (e.g., a display, a speaker, an LED lamp, a touch panel, etc.) that output information to the outside.

[0202] The driving assistance system unit 2030 is composed of various devices that provide functions for preventing accidents and reducing the driving burden on the driver, such as millimeter-wave radar, 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, and AI processors, as well as one or more ECUs that control these devices. In addition, 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.

[0203] The communication module 2013 can communicate with the microprocessor 2031 and components of the vehicle 2001 via the communication port. For example, the communication module 2013 transmits and receives data via the communication port 2033 to and from the drive unit 2002, steering unit 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, front wheels 2007, rear wheels 2008, axle 2009, microprocessor 2031 and memory (ROM, RAM) 2032 in the electronic control unit 2010, and sensors 2021 to 29, which are provided in the vehicle 2001.

[0204] 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 to and from the external device via wireless communication. The communication module 2013 may be located either inside or outside the electronic control unit 2010. The external device may be, for example, a base station, a mobile station, or the like.

[0205] The communication module 2013 may transmit at least one of signals from the above-mentioned various sensors 2021-2028 input to the electronic control unit 2010, information obtained based on the signals, and information based on input from the outside (user) obtained via the information service unit 2012 to an external device via wireless communication. The electronic control unit 2010, the various sensors 2021-2028, the information service unit 2012, etc. may be referred to as input units that accept input. For example, the PUSCH transmitted by the communication module 2013 may include information based on the above-mentioned input.

[0206] The communication module 2013 receives various information (traffic information, traffic signal information, vehicle-to-vehicle information, etc.) transmitted from external devices and displays it on an information service unit 2012 provided in the vehicle 2001. The information service unit 2012 may be called an output unit that outputs information (for example, outputs information to a device such as a display or speaker based on the PDSCH (or data / information decoded from the PDSCH) received by the communication module 2013). The communication module 2013 also stores the various information received from external devices in a 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, steering unit 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, front wheels 2007, rear wheels 2008, axles 2009, sensors 2021 to 2029, etc. provided in the vehicle 2001.

[0207] (Summary of the embodiment) As described above, according to the embodiment of the present invention, there is provided a terminal having a control unit that determines a TDD pattern that starts with an uplink symbol and includes at least one of a downlink symbol and a flexible symbol following the uplink symbol in one TDD (Time division duplex) period in a TDD-based NTN (Non-Terrestrial Network), and a communication unit that performs communication applying the TDD pattern.

[0208] With the above configuration, the terminal 20 can support a TDD pattern starting from the UL and extend the slot format to reduce interference in the NTN environment and the TN environment, i.e., improve performance when applying TDD (Time division duplex) in the NTN (Non-Terrestrial Network) environment.

[0209] The communication unit may receive a slot format notification from a base station, and the control unit may determine, based on the slot format notification, a TDD pattern in one slot, starting with an uplink symbol and including at least one of a downlink symbol and a flexible symbol following the uplink symbol. With this configuration, the terminal 20 can support a TDD pattern starting from a UL and extend the slot format to reduce interference in an NTN environment and a TN environment.

[0210] The control unit may use different slot format tables for NTN and TN (Terrestrial Network). With this configuration, the terminal 20 can support a TDD pattern starting from the UL and extend the slot format to reduce interference in the NTN environment and the TN environment.

[0211] The control unit may assume that the start timing of the TDD cycle in the NTN (Terrestrial Network) is different from the start timing of the TDD cycle in the TN (Terrestrial Network). With this configuration, the terminal 20 can support a TDD pattern that starts from the UL and extend the slot format, thereby reducing interference in the NTN environment and the TN environment.

[0212] The control unit may determine the start timing of a TDD cycle in the NTN and the start timing of a TDD cycle in the TN (Terrestrial Network) based on a time offset between the start timing of a TDD cycle in the NTN and the start timing of a TDD cycle in the TN. With this configuration, the terminal 20 can reduce interference in an NTN environment and a TN environment by supporting a TDD pattern that starts from an UL and extending a slot format.

[0213] Furthermore, according to an embodiment of the present invention, there is provided a communication method in which a terminal executes the following procedures: a procedure for determining a TDD pattern starting from an uplink symbol and including at least one of a downlink symbol and a flexible symbol following the uplink symbol, in one TDD period in a TDD-based Non-Terrestrial Network (NTN); and a procedure for performing communication applying the TDD pattern.

[0214] With the above configuration, the terminal 20 can support a TDD pattern starting from the UL and extend the slot format to reduce interference in the NTN environment and the TN environment, i.e., improve performance when applying TDD (Time division duplex) in the NTN (Non-Terrestrial Network) environment.

[0215] (Supplementary Notes on the Embodiments) Although the embodiments of the present invention have been described above, the disclosed invention is not limited to such embodiments, and those skilled in the art will understand various modifications, alterations, alternatives, and substitutions. While specific numerical examples have been used to facilitate understanding of the invention, unless otherwise specified, these numerical values ​​are merely examples, and any appropriate values ​​may be used. The division of items in the above description is not essential to the present invention; matters described in two or more items may be used in combination as needed, and matters described in one item may apply to matters described in another item (as long as there is no contradiction). Boundaries between functional units or processing units in functional block diagrams do not necessarily correspond to boundaries between physical components. The operations of multiple functional units may be performed by a single physical component, or the operations of a single functional unit may be performed by multiple physical components. The order of processing steps described in the embodiments may be reversed as long as there is no contradiction. For convenience of processing description, the base station 10 and terminal 20 have been described using functional block diagrams, but such devices may be realized by hardware, software, or a combination thereof. The software operated by the processor of the base station 10 in accordance with an embodiment of the present invention and the software operated by the processor of the terminal 20 in accordance with an embodiment of the present invention may each be stored in random access memory (RAM), flash memory, read-only memory (ROM), EPROM, EEPROM, register, hard disk (HDD), removable disk, CD-ROM, database, server, or any other suitable storage medium.

[0216] Furthermore, the notification of information is not limited to the aspects / embodiments described in the present disclosure, and may be performed using other methods. For example, the notification of information may be performed by physical layer signaling (e.g., Downlink Control Information (DCI), Uplink Control Information (UCI)), higher layer signaling (e.g., Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling), broadcast information (Master Information Block (MIB), System Information Block (SIB)), other signals, or a combination thereof. Furthermore, the RRC signaling may be referred to as an RRC message, and may be, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, or the like.

[0217] Each aspect / embodiment described in the present disclosure may be applied to at least one of systems using LTE (Long Term Evolution), LTE-Advanced (LTE-A), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), FRA (Future Radio Access), NR (New Radio), 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-Wide Band), Bluetooth (registered trademark), or other suitable systems, and next-generation systems enhanced based on these. Furthermore, a combination of multiple systems (e.g., a combination of at least one of LTE and LTE-A with 5G, etc.) may also be applied.

[0218] The order of the procedures, sequences, flowcharts, etc. of each aspect / embodiment described herein may be rearranged unless it is consistent. For example, the methods described in this disclosure present elements of various steps using an example order and are not limited to the particular order presented.

[0219] In this specification, a specific operation described as being performed by the base station 10 may be performed by its upper node in some cases. In a network consisting of one or more network nodes having the base station 10, it is clear that various operations performed for communication with the terminal 20 may be performed by at least one of the base station 10 and another network node other than the base station 10 (such as, but not limited to, an MME or an S-GW). Although the above example illustrates a case where there is one other network node other than the base station 10, the other network node may be a combination of multiple other network nodes (such as an MME and an S-GW).

[0220] The information, signals, etc. described in the present disclosure may be output from a higher layer (or a lower layer) to a lower layer (or a higher layer), or may be input / output via multiple network nodes.

[0221] Input and output information may be stored in a specific location (for example, memory) or may be managed using a management table. Input and output information may be overwritten, updated, or added to. Output information may be deleted. Input information may be transmitted to another device.

[0222] In the present disclosure, the determination may be made based on a value represented by one bit (0 or 1), a Boolean value (true or false), or a numerical comparison (e.g., comparison with a predetermined value).

[0223] Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0224] Software, instructions, information, etc. may also be transmitted or received over a transmission medium. For example, if software is transmitted from a website, server, or other remote source using wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and / or wireless technologies (such as infrared, microwave), then these wired and / or wireless technologies are included within the definition of transmission media.

[0225] 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. that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0226] 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). Furthermore, a signal may be a message. Furthermore, a component carrier (CC) may be called a carrier frequency, a cell, a frequency carrier, etc.

[0227] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0228] Furthermore, the information, parameters, etc. described in the present disclosure may be expressed using absolute values, may be expressed using relative values ​​from a predetermined value, or may be expressed using other corresponding information. For example, a radio resource may be indicated by an index.

[0229] The names used for the above-described parameters are not intended to be limiting in any way. Furthermore, the mathematical expressions using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (e.g., PUCCH, PDCCH, etc.) and information elements may be identified by any suitable names, and therefore the various names assigned to these various channels and information elements are not intended to be limiting in any way.

[0230] In the present disclosure, terms such as "base station (BS)," "radio base station," "base station device," "fixed station," "NodeB," "eNodeB (eNB)," "gNodeB (gNB)," "access point," "transmission point," "reception point," "transmission / reception point," "cell," "sector," "cell group," "carrier," and "component carrier" may be used interchangeably. A base station may also be referred to by terms such as a macrocell, a small cell, a femtocell, and a picocell.

[0231] A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, the overall coverage area of ​​the base station can be partitioned into multiple smaller areas, and each smaller area can also be provided with communication services by a base station subsystem (e.g., a small indoor base station (RRH: Remote Radio Head)). The terms "cell" or "sector" refer to part or all of the coverage area of ​​a base station and / or base station subsystem that provides communication services within that coverage.

[0232] In the present disclosure, the base station transmitting information to a terminal may be interpreted as the base station instructing the terminal to control or operate based on the information.

[0233] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," and the like may be used interchangeably.

[0234] A mobile station may also be referred to 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 suitable terminology.

[0235] At least one of the base station and the mobile station may be referred to as a transmitting device, a receiving device, a communication device, etc. At least one of the base station and the mobile station may be a device mounted on a mobile object, the mobile object itself, etc. The mobile object refers to a movable object, and may move at any speed. Naturally, this also includes cases where the mobile object is stationary. Examples of the mobile object include, but are not limited to, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcars, rickshaws, ships and other watercraft, airplanes, rockets, satellites, drones (registered trademark), multicopters, quadcopters, balloons, and objects mounted thereon. The mobile object may also be a mobile object that moves autonomously based on an operational command. It may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile object (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). At least one of the base station and the mobile station may be 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.

[0236] Furthermore, a base station in the present disclosure may be read as a user terminal. For example, the aspects / embodiments of the present disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between multiple terminals 20 (which may be called, for example, Device-to-Device (D2D) or Vehicle-to-Everything (V2X)). In this case, the terminal 20 may be configured to have the functions of the base station 10 described above. Furthermore, terms such as "uplink" and "downlink" may be read as terms corresponding to terminal-to-terminal communication (for example, "side"). For example, terms such as an uplink channel and a downlink channel may be read as a side channel.

[0237] Similarly, the user terminal in the present disclosure may be read as a base station, in which case the base station may be configured to have the functions of the user terminal described above.

[0238] As used in this disclosure, the terms "determining" and "determining" may encompass a wide variety of actions. "Determining" and "determining" may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, searching, inquiring (e.g., searching in a table, database, or other data structure), ascertaining, and the like. "Determining" and "determining" may also include receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory), and the like. Furthermore, "judgment" and "decision" can include regarding resolving, selecting, choosing, establishing, comparing, etc. as having been "judged" or "decided." In other words, "judgment" and "decision" can include regarding some action as having been "judged" or "decided." Furthermore, "judgment (decision)" can be interpreted as "assuming," "expecting," "considering," etc.

[0239] The terms "connected," "coupled," or any variation thereof, refer to any direct or indirect connection or coupling between two or more elements, and may 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 may be physical, logical, or a combination thereof. For example, "connected" may be read as "access." As used in this disclosure, two elements may be considered to be "connected" or "coupled" to each other using one or more wires, cables, and / or printed electrical connections, as well as electromagnetic energy having wavelengths in the radio frequency range, microwave range, and optical (both visible and invisible) range, as some non-limiting and non-exhaustive examples.

[0240] The reference signal may be abbreviated as RS (Reference Signal) or may be called a pilot depending on the applicable standard.

[0241] As used in this disclosure, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

[0242] As used in this disclosure, any reference to an element using a designation such as "first," "second," etc. does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed or that the first element must in some way precede the second element.

[0243] The "means" in the configuration of each of the above devices may be replaced with "part," "circuit," "device," etc.

[0244] When the terms "include," "including," and variations thereof are used in this disclosure, these terms are intended to be inclusive, similar to the term "comprising." Furthermore, when the term "or" is used in this disclosure, it is not intended to be an exclusive or.

[0245] A radio 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 called a subframe. A subframe may further be composed of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) that is independent of numerology.

[0246] Numerology may be communication parameters that apply to the transmission and / or reception of a signal or channel, such as subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame structure, specific filtering operations performed by the transceiver in the frequency domain, specific windowing operations performed by the transceiver in the time domain, etc.

[0247] A slot may be composed of one or more symbols (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol or a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol) in the time domain. A slot may be a time unit based on numerology.

[0248] A slot may include multiple minislots. Each minislot may consist of one or multiple symbols in the time domain. A minislot may also be called a subslot. A minislot may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (or PUSCH) mapping type B.

[0249] The radio frame, subframe, slot, minislot, and symbol all represent time units for transmitting signals, and may be referred to by other names corresponding to the radio frame, subframe, slot, minislot, and symbol.

[0250] For example, one subframe may be called a transmission time interval (TTI), multiple consecutive subframes may be called a TTI, or one slot or one minislot may be called a TTI. That is, at least one of the subframe and the TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (for example, 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, minislot, etc. instead of a subframe.

[0251] Here, TTI refers to, for example, the smallest time unit for scheduling in wireless communication. For example, in an LTE system, a base station performs scheduling to allocate wireless resources (such as frequency bandwidth and transmission power that can be used by each terminal 20) to each terminal 20 in TTI units. Note that the definition of TTI is not limited to this.

[0252] The TTI may be a transmission time unit for a channel-encoded data packet (transport block), a code block, a code word, etc., or may be a processing unit for scheduling, link adaptation, etc. When a TTI is given, the time interval (e.g., the number of symbols) to which a transport block, a code block, a code word, etc. is actually mapped may be shorter than the TTI.

[0253] When one slot or one minislot is called a TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the minimum time unit for scheduling. Also, the number of slots (minislots) constituting the minimum time unit for scheduling may be controlled.

[0254] A TTI having a time length of 1 ms may be called a regular TTI (TTI in LTE Rel. 8-12), normal TTI, long TTI, regular subframe, normal subframe, long subframe, slot, etc. A TTI shorter than a regular TTI may be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, minislot, subslot, slot, etc.

[0255] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) may be interpreted as a TTI having a time length of more than 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be interpreted as a TTI having a TTI length shorter than the TTI length of a long TTI and greater than or equal to 1 ms.

[0256] A resource block (RB) is a resource allocation unit in the time domain and the frequency domain, and may include one or more consecutive subcarriers in the frequency domain. The number of subcarriers included in an RB may be the same regardless of the numerology, for example, 12. The number of subcarriers included in an RB may be determined based on the numerology.

[0257] The time domain of an RB may include one or more symbols and may have a length of one slot, one minislot, one subframe, or one TTI. One TTI, one subframe, etc. may each be composed of one or more resource blocks.

[0258] Note that one or more RBs may also be called a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, etc.

[0259] Furthermore, a resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource region of one subcarrier and one symbol.

[0260] A Bandwidth Part (BWP) (which may also be referred to as a fractional bandwidth) may represent a subset of contiguous common resource blocks (RBs) for a given numerology on a given carrier, where the common RBs may be identified by their index relative to a Common Reference Point of the carrier. PRBs may be defined in a BWP and numbered within the BWP.

[0261] The BWP may include a BWP for UL (UL BWP) and a BWP for DL ​​(DL BWP). One or more BWPs may be configured for a UE within one carrier.

[0262] At least one of the configured BWPs may be active, and the UE may not expect to transmit or receive a given signal / channel outside the active BWP. Note that the terms "cell," "carrier," etc. in this disclosure may be read as "BWP."

[0263] The above-described structures of radio frames, subframes, slots, minislots, symbols, etc. are merely examples, and various changes may be made to the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, etc.

[0264] In this disclosure, where articles are added by translation, such as a, an, and the in English, the disclosure may include that the nouns following these articles are in the plural form.

[0265] In the present disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "coupled" may also be interpreted in the same way as "different."

[0266] The aspects / embodiments described in this disclosure may be used alone, in combination, or switched depending on the implementation. Notification of predetermined information (e.g., notification that "X is true") is not limited to explicit notification, but may be implicit (e.g., not notifying the predetermined information).

[0267] Although the present disclosure has been described in detail above, it is clear to those skilled in the art that the present disclosure is not limited to the embodiments described herein. The present disclosure can be implemented in modified and altered forms without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the description of the present disclosure is intended to be illustrative and does not have any limiting meaning on the present disclosure.

[0268] 10 Base station 110 Transmitter 120 Receiver 130 Setting unit 140 Control unit 20 Terminal 210 Transmitter 220 Receiver 230 Setting unit 240 Control unit 1001 Processor 1002 Storage device 1003 Auxiliary storage device 1004 Communication device 1005 Input device 1006 Output device 2001 Vehicle 2002 Drive unit 2003 Steering unit 2004 Accelerator pedal 2005 Brake pedal 2006 Shift lever 2007 Front wheels 2008 Rear wheels 2009 Axle 2010 Electronic control unit 2012 Information service unit 2013 Communication module 2021 Current sensor 2022 Rotation speed sensor 2023 Tire 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 assistance system unit 2031 Microprocessor 2032 Memory (ROM, RAM) 2033 Communication port (IO port)

Claims

1. A terminal having: a control unit that determines a TDD pattern that starts with an uplink symbol and includes at least one of a downlink symbol and a flexible symbol following the uplink symbol in one TDD period in a TDD-based NTN (Non-Terrestrial Network); and a communication unit that performs communication applying the TDD pattern.

2. The terminal according to claim 1, wherein the communication unit receives a slot format notification from a base station, and the control unit determines, based on the slot format notification, a TDD pattern in one slot that starts with an uplink symbol and includes at least one of a downlink symbol and a flexible symbol following the uplink symbol.

3. The terminal according to claim 1, wherein the control unit uses different slot format tables for NTN and TN (Terrestrial Network).

4. The terminal according to claim 1, wherein the control unit assumes that the start timing of the TDD cycle in the NTN is different from the start timing of the TDD cycle in the TN (Terrestrial Network).

5. The terminal of claim 1, wherein the control unit determines the start timing of the TDD cycle in the NTN and the start timing of the TDD cycle in the TN (Terrestrial Network) based on a time offset between the start timing of the TDD cycle in the NTN and the start timing of the TDD cycle in the TN (Terrestrial Network).

6. A communication method in which a terminal executes the following procedures: determining a TDD pattern starting from an uplink symbol and including at least one of a downlink symbol and a flexible symbol following the uplink symbol in one TDD period in a TDD-based non-terrestrial network (NTN); and executing communication applying the TDD pattern.

Images