Terminal and communication method

Abstract

A terminal including: a reception unit that receives, from a base station, control information for activating a semi-persistent scheduling (SPS)-physical downlink shared channel (PDSCH) in a non-terrestrial network (NTN) or multicast and broadcast services (MBS); a control unit that determines an operation method related to feedback corresponding to the control information on the basis of a first setting set by the base station; and a transmission unit that transmits the feedback to the base station when it is determined to provide the feedback.

Description

[Technical Field]

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

[0002] For NR (New Radio) (also known as "5G"), the successor system to LTE (Long Term Evolution), technologies that satisfy requirements such as 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 are being considered (for example, Non-Patent Document 1).

[0003] Currently, non-terrestrial networks (NTNs) are being considered. NTNs 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). [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] 3GPP TS 38.300 V16.6.0(2021-06) [Non-patent document 2] 3GPP TR 38.821 V16.0.0 (2019-12) [Non-patent document 3] Konishi et al., "A Study on Downlink Spectrum Sharing in HAPS Mobile Communication Systems," Institute of Electronics, Information and Communication Engineers General Conference, B-17-1, 2020 [Non-patent document 4] 3GPP TS 38.214 V16.6.0(2021-06) Summary of the Invention [Problem to be solved by the invention]

[0005] In NTN, the distance between the base station and the terminal in the sky is very large, so the propagation delay is larger than in a terrestrial network (TN). In addition, in the case of LEO (Low Earth orbit) or HAPS (High Altitude Platform Station), situations occur where the base station moves. For this reason, support for disabling HARQ (Hybrid Symmetric repeat request) feedback in NTN is being considered.

[0006] Also, in PDSCH (Physical Downlink Shared Channel) transmission in MBS (Multicast and broadcast services), an operation of feeding back only NACK or disabling feedback is being considered.

[0007] Here, even if HARQ feedback is disabled, feedback indicating whether activation of SPS (Semi-persistent scheduling) has been successful or not is still necessary in the base station.

[0008] The present invention has been made in view of the above points, and has an object to appropriately perform activation of SPS (Semi-persistent scheduling) in a wireless communication system. [Means for solving the problem]

[0009] According to the disclosed technology, a receiving unit that receives, from a base station, first information indicating whether feedback for PDSCH (Physical Downlink Shared Channel) reception is valid or invalid; and a transmitting unit that transmits, to the base station, feedback information for the PDSCH reception based on the first information, wherein the receiving unit receives, from the base station, second information indicating whether feedback for SPS (Semi-Persistent Scheduling) PDSCH is valid or invalid, and when the second information indicates that the feedback is valid, the transmitting unit transmits, to the base station, feedback information for the first SPS PDSCH reception after activation of the SPS PDSCH based on the second information, regardless of whether the feedback indicated by the first information is valid or invalid. A terminal is provided. [Effects of the Invention]

[0010] According to the disclosed technology, activation of SPS (Semi-persistent scheduling) can be performed appropriately in a wireless communication system. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing an example of NTN (1). [Figure 2] FIG. 10 is a diagram showing an example (2) of NTN. [Figure 3] This is a diagram showing an example (3) of NTN. [Figure 4] This is a diagram showing an example (4) of NTN. [Figure 5] FIG. 10 is a diagram illustrating an example of receiving an SPS PDSCH. [Figure 6] FIG. 10 is a diagram illustrating an example of PTM transmission. [Figure 7] 1 is a flowchart showing an example (1) of SPS activation in an embodiment of the present invention. [Figure 8] 10 is a flowchart showing an example (2) of SPS activation in the embodiment of the present invention. [Figure 9] 10 is a flowchart showing an example (3) of SPS activation in an embodiment of the present invention. [Figure 10] 2 is a diagram illustrating an example of a functional configuration of a base station 10 according to an embodiment of the present invention. [Figure 11] FIG. 2 is a diagram illustrating an example of a functional configuration of a terminal 20 according to the embodiment of the present invention. [Figure 12] 2 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. [Figure 13] FIG. 2 is a diagram showing an example of the configuration of a vehicle 2001 according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] 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.

[0013] In the operation of the wireless communication system according to the embodiment of the present invention, existing technologies are used as appropriate. However, the existing technologies are, for example, but 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.

[0014] Furthermore, in the embodiments of the present invention described below, terms used in existing LTE, 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), are used. This is for convenience of description, and similar signals, functions, etc. may be referred to by other names. Furthermore, 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 signals used in NR are not necessarily designated as "NR-."

[0015] Furthermore, in the embodiments of the present invention, the duplex method may be a TDD (Time Division Duplex) method, an FDD (Frequency Division Duplex) method, or other methods (for example, Flexible Duplex, etc.).

[0016] Furthermore, in the embodiments of the present invention, when radio parameters and the like are "configured," it may mean that predetermined values ​​are pre-configured, or that radio parameters notified from the base station 10 or the terminal 20 are set.

[0017] Figure 1 shows an example of an NTN (1). An NTN (Non-Terrestrial Network) uses non-terrestrial devices such as satellites to provide services to areas that cannot be covered by terrestrial 5G networks, primarily due to cost. NTN also enables the provision of 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.

[0018] 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 no terrestrial base stations are located, such as mountainous regions.

[0019] 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 a 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, on NR-PBCH, and is also called broadcast information.

[0020] 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).

[0021] 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.

[0022] 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 the feeder link, and the connection between the satellite 10A and the UE 20 is called the service link.

[0023] As shown in Figure 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.

[0024] 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.

[0025] 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.

[0026] For example, NTN can extend the coverage of a 5G network to unserved or served areas. Furthermore, 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 parameters related to determining a timing advance (TA) based on information related to a satellite or an aircraft.

[0027] FIG. 4 is a diagram showing an example (4) of an NTN. FIG. 4 shows an example of an NTN network architecture assumed in the case of a transparent payload. As shown in FIG. 4, a CN (Core Network) 10D, a gNB 10C, and a gateway 10B are connected. The gateway 10B is connected to a satellite 10A via a feeder link. The satellite 10A is connected to a terminal 20A or a VSAT (Very Small Aperture Terminal) 20B via a service link. An NR Uu is established between the gNB 10C and the terminal 20A or the VSAT 20B.

[0028] NTN's network architecture may be FDD or TDD. Terrestrial cells may be fixed or mobile. Terminal 20 may have GNSS (Global Navigation Satellite System) capabilities. For example, a power class 3 handheld device may be assumed in FR1. A VSAT device may be assumed at least in FR2.

[0029] NTN's 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.

[0030] In NTN, it is necessary to consider long propagation delays, mobility of LEOs or HAPS, and communication via GEOs, LEOs, or HAPS. Because of these NTN characteristics, enhancements to HARQ operation are being considered. For example, HARQ feedback may be disabled. When HARQ feedback is disabled, two consecutive DL transport blocks can be transmitted in one HARQ process without waiting for feedback.

[0031] FIG. 5 is a diagram showing an example of receiving an SPS PDSCH. Existing terrestrial networks support SPS (Semi-persistent scheduling) as shown in FIG. 5. FIG. 5 shows an example in which the number of HARQ processes is two, and SPS-PDSCHs corresponding to HPN=0 and HPN=1 are scheduled alternately. Note that the K1 value is the offset from the PDSCH to the PUCCH that transmits the corresponding HARQ-ACK. The activation DCI allocates initial PDSCH reception and notifies SPS activation. The HARQ-ACK corresponding to the initial PDSCH reception is used to confirm the success of the activation. The SPS-PDSCH following the initial PDSCH is transmitted at a predetermined period without transmitting the corresponding PDCCH.

[0032] The release DCI indicates that the SPS has been released without PDSCH allocation, and the HARQ-ACK corresponding to the release DCI is used to confirm that the release has been successful.

[0033] The HARQ process number corresponding to each PDSCH reception is determined based on the slot index and higher layer parameters that define the number of HARQ processes allocated to the SPS.

[0034] For example, the HARQ process ID may be calculated as follows: where CURRENT_slot is [(SFN × numberOfSlotsPerFrame) + slot number within a frame], and numberOfSlotsPerFrame is the number of consecutive slots per frame.

[0035] HARQ Process ID = [floor (CURRENT_slot × 10 / (numberOfSlotsPerFrame × periodicity))] modulo nrofHARQ-Processes or HARQ Process ID = [floor (CURRENT_slot × 10 / (numberOfSlotsPerFrame × periodicity))] modulo nrofHARQ-Processes + harq-ProcID-Offset

[0036] Here, it is considered whether to disable feedback for the initial PDSCH corresponding to SPS activation. Note that HARQ feedback corresponding to SPS release may always be performed regardless of whether feedback is enabled or disabled.

[0037] The success or failure of receiving the activation command should be reported to the base station 10. If the reception of the activation command fails and the failure is not reported to the base station 10, a number of subsequent SPS-PDSCHs will not be received by the terminal 20. On the other hand, if feedback is enabled to perform HARQ feedback corresponding to the initial SPS-PDSCH, HARQ feedback of all subsequent SPS-PDSCHs will also be enabled.

[0038] Furthermore, Multicast and broadcast services (MBS) is being considered for NR. In MBS, a group scheduling mechanism, for example, improvement of reliability by reporting HARQ feedback to base station 10, is being considered. MBS may be applied to UEs in the RRC_IDLE or RRC_INACTIVE state in addition to UEs in the RRC_CONNECTED state.

[0039] In the UE in the RRC_CONNECTED state, the MBS may be received simultaneously with the unicast reception operation, or UL feedback may be provided for the MBS reception to improve reliability.

[0040] In the RRC_IDLE or RRC_INACTIVE state, a UE may be capable of PTM (Point to Multipoint) reception, or may be capable of operating in the same manner as a UE in the RRC_CONNECTED state as much as possible.

[0041] Figure 6 is a diagram showing an example of PTM transmission. As shown in Figure 6, a group-common PDSCH is scheduled by a group-common PDCCH. The group-common PDCCH is scheduled for an MBS group of UEs in the RRC_CONNECTED state. The CRC (Cyclic redundancy check) of the group-common PDCCH and the PDSCH are scrambled by a group-common RNTI (Radio Network Temporary Identifier). In PTM transmission, the RAN node delivers a single copy of an MBS data packet to a group of UEs.

[0042] Point-to-Point (PTP) transmission may also be supported. In PTP transmission, a RAN node delivers separate copies of MBS data packets to individual UEs. In PTP transmission, a UE-specific PDCCH is used to schedule a UE-specific PDSCH for a UE in RRC_CONNECTED state. The CRC of the PDCCH and the PDSCH are scrambled by a UE-specific RNTI. That is, the MBS packets are transmitted by unicast transmission.

[0043] For HARQ feedback corresponding to multicast or broadcast PDSCH, the operations shown in 1) and 2) below may be performed.

[0044] 1) ACK / NACK feedback may be supported. A terminal 20 that has successfully received and decoded may send an ACK. A terminal 20 that has failed to receive and decode may send a NACK. PUCCH-Config may be configurable for multicast. Sharing or orthogonality of PUCCH resources between UEs may be determined by the network. The HARQ-ACK codebook may support Type 1 and Type 2. Multiplexing may be possible for unicast and multicast.

[0045] 2) NACK-only feedback may be supported. A terminal 20 that successfully receives and decodes may not transmit feedback. A terminal 20 that fails to receive and decode may transmit a NACK. In a certain terminal 20, PUCCH resource configuration may be configured separately for unicast and groupcast. PUCCH resource configuration may be shared or orthogonal between UEs. PUCCH resources may be shared or separated.

[0046] Furthermore, regarding enabling or disabling HARQ feedback corresponding to a multicast or broadcast PDSCH, feedback may be always enabled or always disabled for each UE by RRC signaling, or whether feedback is enabled or disabled may be notified by DCI. When whether feedback is enabled or disabled is notified by DCI, the DCI that schedules the group-common PDSCH may also notify whether feedback is enabled or disabled.

[0047] Here, it is considered whether to disable feedback for the initial PDSCH corresponding to SPS activation. Success or failure in receiving the activation command should be reported to the base station 10. If reception of the activation command fails and the failure is not reported to the base station 10, subsequent SPS-PDSCHs will not be received by the terminal 20. On the other hand, if feedback is enabled to perform HARQ feedback corresponding to the initial SPS-PDSCH, HARQ feedback for all subsequent SPS-PDSCHs will also be enabled. However, the operation of always performing ACK / NACK feedback for the initial PDSCH corresponding to SPS activation may not be applicable due to a lack of PUCCH resources.

[0048] Therefore, in the NTN and / or MBS, feedback for the initial SPS-PDSCH corresponding to SPS activation may be configured as shown in A)-C) below. Alternatively, any of A)-C) below may be applied without any configuration. Note that the configuration shown in A)-C) may be configured for each HARQ process or for each UE. Note that the terminal 20 may receive information indicating which of A)-C) below should be applied from the base station 10.

[0049] A) The HARQ-ACK may be reported regardless of the network configuration or notification indicating whether the HARQ feedback for the SPS-PDSCH is valid or invalid. That is, the HARQ-ACK may be reported regardless of whether the HARQ feedback applied to the SPS-PDSCH after the initial SPS-PDSCH is valid or invalid. The terminal 20 may assume that the DAI (Downlink Assignment Index) included in the activation DCI is increased.

[0050] 7 is a flowchart showing an example (1) of SPS activation according to an embodiment of the present invention. In step S11, terminal 20 receives DCI activating SPS-PDSCH. In the following step S12, terminal 20 reports HARQ-ACK corresponding to the initial SPS-PDSCH to the network, regardless of the setting or instruction from the network regarding HARQ feedback to be applied to SPS-PDSCHs after the initial SPS-PDSCH.

[0051] B) The HARQ-ACK may be reported based on a network setting or notification indicating whether HARQ feedback for the initial SPS-PDSCH is valid or invalid. That is, terminal 20 may apply a network setting or notification indicating whether HARQ feedback applied to SPS-PDSCHs after the initial SPS-PDSCH is valid or invalid to the HARQ feedback for the initial SPS-PDSCH.

[0052] 8 is a flowchart showing an example (2) of SPS activation according to an embodiment of the present invention. In step S21, terminal 20 receives DCI activating SPS-PDSCH. In the following step S22, terminal 20 determines whether to report a HARQ-ACK corresponding to the initial SPS-PDSCH to the network, based on a setting or instruction from the network regarding HARQ feedback applied to SPS-PDSCHs after the initial SPS-PDSCH.

[0053] C) HARQ feedback for the initial SPS-PDSCH may be reported to the network in a manner other than HARQ feedback.

[0054] 9 is a flowchart showing an example (3) of SPS activation according to an embodiment of the present invention. In step S31, terminal 20 receives DCI activating SPS-PDSCH. In the following step S32, terminal 20 reports HARQ-ACK corresponding to the initial SPS-PDSCH to the network by means other than HARQ feedback.

[0055] Note that, if a notification indicating whether HARQ feedback is enabled or disabled is included in the activation DCI, the notification may be ignored. In other words, the notification is applied to SPS-PDSCHs subsequent to the initial SPS-PDSCH. Note that, if a configuration indicating whether HARQ feedback is enabled or disabled is provided for an SPS, the configuration may be ignored. In other words, the configuration is applied to SPS-PDSCHs subsequent to the initial SPS-PDSCH. Note that the above "initial SPS-PDSCH corresponding to SPS activation" and the above "initial SPS-PDSCH" may be replaced with "SPS activation". Furthermore, "SPS activation" may be replaced with "SPS release".

[0056] By performing the above operations, the network can decide whether feedback is mandatory or not based on the level of performance required and the amount of PUCCH resources available.

[0057] In addition, for feedback in NTN and / or MBS, the UE capabilities shown in 1)-4) below may be reported to the network. The UE capabilities may be defined for each HARQ process or for each UE.

[0058] 1) Whether to support setting feedback for the initial SPS-PDSCH corresponding to SPS activation. 2) Whether or not the operation described in A) above is supported. 3) Whether or not the operation described in B) above is supported. 4) Whether or not the operation shown in C) above is supported.

[0059] By defining the above UE capabilities, the network can decide whether to make feedback mandatory or not based on the behavior of the terminal 20. The terminal 20 can also choose between a simple implementation or improving the reliability of activation without consuming resources through subsequent PUCCH transmissions.

[0060] In the above C), the method for reporting successful SPS activation detection other than HARQ feedback may be a scheduling request (SR). Alternatively, the method may be a medium access control (MAC-CE) control element (MAC-CE). For example, a MAC-CE field indicating SPS activation detection confirmation may be defined, and the MAC-CE field may be transmitted to the network. In the MAC-CE field, for example, "0" may indicate failure and "1" may indicate success. Alternatively, for example, the MAC-CE may not include a field indicating SPS activation detection confirmation, and if the network receives the MAC-CE, it may be assumed that the SPS activation detection confirmation is successful. Alternatively, for example, multiple bit fields may be used to indicate multiple CC, BWP, and / or SPS activation or deactivation (release) values.

[0061] When SPS activation is successfully detected, terminal 20 may transmit information indicating successful SPS activation detection in the next earliest transmission opportunity (e.g., SR or PUSCH). The next earliest transmission opportunity may be determined based on processing time. For example, when activation is received in slot n, the next earliest transmission opportunity may be the earliest transmission opportunity after slot n plus the PUSCH preparation period.

[0062] As mentioned above, for terminals 20 with other UL resources, instead of scheduling new PUCCH resources, successful detection of SPS activation can be reported via the other UL resources, i.e., the reliability of activation can be improved without consuming resources for subsequent PUCCH transmissions.

[0063] Furthermore, confirmation of SPS activation detection may be requested in the NTN and / or MBS via a DCI other than the activation DCI or MAC-CE. When the terminal 20 receives the request, it may report whether or not the SPS activation detection was successful, as described above. The request may be made for each UE or for each HARQ process.

[0064] For example, the request may be signaled by a new DCI format, DCI field, CRC for scrambling the RNTI of the DCI, search space, CORESET (Control resource set), or a new MAC-CE. The DCI field may be a new field or a combination of existing fields. The DCI format may be an existing DCI format, such as DCI format 1_0, 1_1, or 2_X.

[0065] The request may be notified by group common signaling or UE-specific signaling, and the signaling notifying the request may include information indicating which SPS to activate.

[0066] The request may result in an ACK or NACK being reported, where an ACK may indicate successful detection of SPS activation, and a NACK may indicate unsuccessful detection of SPS activation.

[0067] The request may report only a NACK, no transmission if SPS activation is successfully detected, or a NACK if SPS activation is not detected.

[0068] By operating as described above, for example, when the communication environment is not good, the terminal 20 can be requested to report whether or not the SPS activation was detected successfully, thereby improving reliability.

[0069] According to the above-described embodiment, the terminal 20 can control the feedback for the initial SPS-PDSCH as needed in an NTN environment or an MBS environment, thereby improving the reliability of SPS activation.

[0070] That is, in a wireless communication system, activation of SPS (Semi-persistent scheduling) can be performed appropriately.

[0071] (Device configuration) Next, a description will be given of an example of the functional configuration of the base station 10 and the terminal 20 that execute the processes and operations described above. 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.

[0072] <Base station 10> Fig. 10 is a diagram showing an example of the functional configuration of base station 10 in the embodiment of the present invention. As shown in Fig. 10, 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 Fig. 10 is merely an example. The functional divisions and names of the functional units may be any names as long as they can perform the operations related to the embodiment of the present invention.

[0073] The transmitter 110 includes 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 includes 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.

[0074] 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.

[0075] As described in the embodiment, 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.

[0076] <Terminal 20> Fig. 11 is a diagram showing an example of the functional configuration of terminal 20 in the embodiment of the present invention. As shown in Fig. 11, terminal 20 has transmitting unit 210, receiving unit 220, setting unit 230, and control unit 240. The functional configuration shown in Fig. 11 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.

[0077] The transmitter 210 creates a transmission signal from transmission data and transmits the transmission signal wirelessly. The receiver 220 receives various signals wirelessly 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.

[0078] 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.

[0079] As described in the embodiment, the control unit 240 controls communication in the NTN. The function unit related to signal transmission in the control unit 240 may be included in the transmitting unit 210, and the function unit related to signal reception in the control unit 240 may be included in the receiving unit 220.

[0080] (Hardware configuration) The block diagrams (FIGS. 10 and 11) 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 the single device or the multiple devices with software.

[0081] Functions include, but are not limited to, judgment, determination, judgment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, election, establishment, comparison, assumption, expectation, consideration, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocation, 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.

[0082] 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. 12 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.

[0083] In the following description, the term "apparatus" can be read 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.

[0084] Each function in the base station 10 and the terminal 20 is realized by loading predetermined 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.

[0085] 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.

[0086] 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. 10 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. 11 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 be transmitted from a network via a telecommunications line.

[0087] 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 ROM (EPROM), an electrically erasable programmable ROM (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.

[0088] 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 disc), a smart card, a flash memory (e.g., a card, a stick, a key drive), a floppy disk, a magnetic strip, etc. The above-mentioned storage medium may be, for example, a database, a server, or other suitable medium including at least one of the storage device 1002 and the secondary storage device 1003.

[0089] 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, or a communication module. 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.

[0090] The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives input from the outside. The output device 1006 is an output device (for example, a display, a speaker, an LED lamp, etc.) that performs output to the outside. Note that the input device 1005 and the output device 1006 may be integrated into one device (for example, a touch panel).

[0091] 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.

[0092] Furthermore, base station 10 and 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, processor 1001 may be implemented using at least one of these pieces of hardware.

[0093] Fig. 13 shows an example configuration of a vehicle 2001. As shown in Fig. 13, 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.

[0094] 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.

[0095] 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).

[0096] 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 rotation speed signal of the front and rear wheels obtained by a rotation speed sensor 2022, an air pressure signal of the front and rear wheels obtained by an air pressure sensor 2023, a vehicle speed signal obtained by a vehicle speed sensor 2024, an acceleration signal obtained by an acceleration sensor 2025, 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.

[0097] 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 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 obtained from external devices via the communication module 2013, etc., to provide various types of multimedia information and multimedia services to the occupants of the vehicle 2001.

[0098] The driving assistance system unit 2030 is composed of various devices that provide functions for preventing accidents and reducing the driver's driving burden, such as a millimeter-wave radar, a LiDAR (Light Detection and Ranging), a camera, a positioning locator (e.g., GNSS, etc.), map information (e.g., high-definition (HD) map, autonomous vehicle (AV) map, etc.), a gyro system (e.g., an IMU (Inertial Measurement Unit), an INS (Inertial Navigation System), etc.), an AI (Artificial Intelligence) chip, and an AI processor, as well as one or more ECUs that control these devices. The driving assistance system unit 2030 also transmits and receives various information via the communication module 2013 to realize the driving assistance function or the autonomous driving function.

[0099] 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.

[0100] 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.

[0101] The communication module 2013 transmits, via wireless communication to an external device, a current signal from the current sensor that is input to the electronic control unit 2010. The communication module 2013 also transmits, via wireless communication to an external device, the rotation speed signals of the front and rear wheels acquired by a rotation speed sensor 2022, the air pressure signals of the front and rear wheels acquired by an air pressure sensor 2023, the vehicle speed signal acquired by a vehicle speed sensor 2024, the acceleration signal acquired by an acceleration sensor 2025, the accelerator pedal depression amount signal acquired by an accelerator pedal sensor 2029, the brake pedal depression amount signal acquired by a brake pedal sensor 2026, the shift lever operation signal acquired by a shift lever sensor 2027, and the detection signals for detecting obstacles, vehicles, pedestrians, etc. acquired by an object detection sensor 2028, which are input to the electronic control unit 2010.

[0102] The communication module 2013 receives various information (traffic information, traffic signal information, inter-vehicle information, etc.) transmitted from external devices and displays it on an information service unit 2012 provided in the vehicle 2001. The communication module 2013 also stores the various information received from the 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, axle 2009, sensors 2021 to 2029, etc. provided in the vehicle 2001.

[0103] (Summary of the embodiment) As described above, according to the embodiment of the present invention, there is provided a terminal in an NTN (Non-Terrestrial Network) or MBS (Multicast and broadcast services), the terminal having: a receiving unit that receives control information for activating an SPS (Semi-persistent scheduling)-PDSCH (Physical Downlink Shared Channel) from a base station; a control unit that determines an operation method for feedback corresponding to the control information based on a first setting that is set by the base station; and a transmitting unit that transmits the feedback to the base station when it is determined that the feedback is to be executed.

[0104] With the above configuration, in an NTN environment or an MBS environment, terminal 20 can control feedback for the initial SPS-PDSCH as needed and improve the reliability of SPS activation. That is, in a wireless communication system, SPS (Semi-persistent scheduling) activation can be performed appropriately.

[0105] The control unit may always determine to perform feedback corresponding to the control information regardless of the second setting indicating whether to perform feedback for the SPS-PDSCH. With this configuration, the terminal 20 can control feedback for the initial SPS-PDSCH as needed in an NTN environment or an MBS environment, thereby improving the reliability of SPS activation.

[0106] The control unit may determine whether to perform feedback corresponding to the control information based on a second setting indicating whether to perform feedback for an SPS-PDSCH. With this configuration, terminal 20 can control feedback for an initial SPS-PDSCH as needed in an NTN environment or an MBS environment, thereby improving the reliability of SPS activation.

[0107] The transmitter may transmit the feedback to the base station via HARQ (Hybrid automatic repeat request) feedback, SR (Scheduling request), or MAC-CE (Medium Access Control - Control Element). With this configuration, the terminal 20 can control the feedback for the initial SPS-PDSCH as needed in an NTN environment or an MBS environment, thereby improving the reliability of SPS activation.

[0108] The receiving unit may receive a signal requesting the feedback from the base station. With this configuration, the terminal 20 can control the feedback for the initial SPS-PDSCH as needed in an NTN environment or an MBS environment, thereby improving the reliability of SPS activation.

[0109] Furthermore, according to an embodiment of the present invention, there is provided a communication method in which a terminal executes a reception procedure for receiving control information for activating an SPS (Semi-persistent scheduling)-PDSCH (Physical Downlink Shared Channel) from a base station in an NTN (Non-Terrestrial Network) or MBS (Multicast and broadcast services), a control procedure for determining an operation method for feedback corresponding to the control information based on a first setting set by the base station, and a transmission procedure for transmitting the feedback to the base station when it is determined that the feedback is to be executed.

[0110] With the above configuration, in an NTN environment or an MBS environment, terminal 20 can control feedback for the initial SPS-PDSCH as needed and improve the reliability of SPS activation. That is, in a wireless communication system, SPS (Semi-persistent scheduling) activation can be performed appropriately.

[0111] (Supplementary explanation of the embodiment) 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; two or more items may be combined as needed, and items described in one item may apply to items described in another item (unless inconsistent). The boundaries between functional units or processing units in the functional block diagram do not necessarily correspond to the 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 the 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. However, such devices may be implemented using 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, registers, hard disk (HDD), removable disk, CD-ROM, database, server or any other suitable storage medium.

[0112] 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.

[0113] Each aspect / embodiment described in the present disclosure may be any of the following: LTE (Long Term Evolution), LTE-Advanced (LTE-A), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), 6th generation mobile communication system (6G), xth generation mobile communication system (xG) (xG (x is, for example, an integer or decimal number)), FRA (Future Radio Access), NR (new Radio), New radio access (NX), Future generation radio access (FX), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE The present invention may be applied to at least one of systems using 802.20, UWB (Ultra-Wideband), Bluetooth (registered trademark), or other appropriate systems, and next-generation systems that are extended, modified, created, or defined based on these systems. The present invention may also be applied to a combination of multiple systems (e.g., a combination of at least one of LTE and LTE-A with 5G).

[0114] The order of the procedures, sequences, flowcharts, etc. of each aspect / embodiment described herein may be changed 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.

[0115] In this specification, a specific operation that is described as being performed by the base station 10 may also 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).

[0116] The information or signals 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.

[0117] 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 sent to another device.

[0118] 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).

[0119] 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.

[0120] 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.

[0121] 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.

[0122] Note that terms explained 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.

[0123] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0124] Furthermore, the information, parameters, etc. described in the present disclosure may be expressed using absolute values, relative values ​​from a predetermined value, or other corresponding information. For example, a radio resource may be indicated by an index.

[0125] 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.

[0126] 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. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, and picocell.

[0127] 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 divided into multiple smaller areas, and each smaller area can be provided with communication service by a base station subsystem (e.g., a small indoor base station (RRH: Remote Radio Head)). The term "cell" or "sector" refers to a part or the entire coverage area of ​​a base station and / or base station subsystem that provides communication service within this coverage.

[0128] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0129] 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.

[0130] At least one of the base station and the mobile station may be called 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 body, or the mobile body itself. The mobile body may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile body (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 also include devices that do 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.

[0131] 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 a plurality of terminals 20 (which may be called, for example, D2D (Device-to-Device) or V2X (Vehicle-to-Everything)). 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] The reference signal may be abbreviated as RS (Reference Signal) or may be called a pilot depending on the applicable standard.

[0136] 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."

[0137] 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.

[0138] The "means" in the configuration of each of the above devices may be replaced with "part," "circuit," "device," etc.

[0139] When used in this disclosure, the terms "include," "including," and variations thereof are intended to be inclusive, similar to the term "comprising." Furthermore, when used in this disclosure, the term "or" is not intended to be an exclusive or.

[0140] 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.

[0141] Numerology may be communication parameters that apply to at least one of transmission and 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, and specific windowing operations performed by the transceiver in the time domain.

[0142] 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.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] 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.

[0150] 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 equal to or greater than 1 ms.

[0151] A resource block (RB) is a resource allocation unit in the time domain and 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 numerology, for example, 12. The number of subcarriers included in an RB may also be determined based on numerology.

[0152] 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.

[0153] 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, or the like.

[0154] 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.

[0155] 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 given BWP and numbered within that BWP.

[0156] 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.

[0157] 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."

[0158] The above-described structures of radio frames, subframes, slots, minislots, symbols, etc. are merely examples. For example, 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. may be changed in various ways.

[0159] 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.

[0160] 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."

[0161] Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched depending on the implementation. Furthermore, notification of predetermined information (e.g., notification that "X is true") is not limited to being done explicitly, but may be done implicitly (e.g., by not notifying the predetermined information).

[0162] 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. [Explanation of symbols]

[0163] 10 base station 110 Transmitter 120 Receiver 130 Setting section 140 Control Unit 20 terminals 210 Transmitter 220 Receiving unit 230 Setting Section 240 Control Unit 1001 processor 1002 Storage device 1003 Auxiliary storage device 1004 Communication equipment 1005 Input Device 1006 Output Device

Claims

1. A receiver that receives, from a base station, first information indicating whether feedback on reception of a PDSCH (Physical Downlink Shared Channel) is enabled or disabled; a transmitter that transmits feedback information for reception of the PDSCH to the base station based on the first information, the receiving unit receives, from the base station, second information indicating whether feedback for a Semi-Persistent Scheduling (SPS) PDSCH is valid; When the second information indicates that the feedback is valid, the transmitter transmits, to the base station, feedback information for reception of the first SPS PDSCH after activation of the SPS PDSCH based on the second information, regardless of whether the feedback indicated by the first information is valid or invalid.

2. The terminal described in claim 1, wherein when the first information indicates that the feedback for receiving the PDSCH is invalid and the second information indicates that the feedback for the SPS PDSCH is valid, the transmitting unit transmits feedback information for receiving the first SPS PDSCH based on the second information.

3. The terminal described in claim 1, wherein when the second information indicates that the feedback for the SPS PDSCH is not valid, the transmitting unit transmits feedback information for receiving the first SPS PDSCH based on the first information.

4. The terminal described in claim 1, wherein the feedback is HARQ (Hybrid Automatic Repeat reQuest) feedback.

5. The terminal of claim 1, wherein activation of the SPS PDSCH is performed based on downlink control information transmitted from the base station.

6. A communication method executed by a terminal, comprising: receiving, from a base station, first information indicating whether feedback on reception of a PDSCH (Physical Downlink Shared Channel) is enabled or disabled; transmitting feedback information for receiving the PDSCH to the base station based on the first information; receiving, from the base station, second information indicating whether feedback for a Semi-Persistent Scheduling (SPS) PDSCH is valid; and when the second information indicates that the feedback is valid, transmitting feedback information for a first reception of an SPS PDSCH after activation of an SPS PDSCH to the base station based on the second information, regardless of whether the feedback indicated by the first information is valid or invalid.

7. A transmitting unit that transmits first information indicating whether a Hybrid Automatic Repeat reQuest (HARQ) feedback for a Physical Downlink Shared Channel (PDSCH) is enabled or disabled to a terminal; a receiving unit that receives HARQ feedback information for reception of the PDSCH from the terminal based on the first information, The transmitter transmits second information indicating whether HARQ feedback for a Semi-Persistent Scheduling (SPS) PDSCH is enabled; The receiving unit receives HARQ feedback information for receiving a first SPS PDSCH from the terminal after activation of the SPS PDSCH; The HARQ feedback information is transmitted by the terminal based on the second information when the second information indicates that the HARQ feedback is valid, regardless of whether the HARQ feedback indicated by the first information is valid or invalid.

8. A communication system having a base station and a terminal, The base station transmitting first information indicating whether a Hybrid Automatic Repeat reQuest (HARQ) feedback for a Physical Downlink Shared Channel (PDSCH) is enabled or disabled to the terminal; Transmitting second information indicating whether HARQ feedback for a Semi-Persistent Scheduling (SPS) PDSCH is enabled; The terminal receiving the first information from the base station; Transmitting feedback information for receiving the PDSCH to the base station based on the first information; receiving the second information from the base station; When the second information indicates that the feedback is valid, feedback information for the first reception of an SPS PDSCH after activation of an SPS PDSCH is transmitted to the base station based on the second information, regardless of whether the feedback indicated by the first information is valid or invalid.

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