User terminal and wireless communication method

Abstract

Retransmission control for at least one of broadcast transmission and multicast transmission is appropriately controlled. The user terminal includes: a receiving unit that receives specific information transmitted via at least one of broadcast and multicast; and a control unit that controls reporting of retransmission control information for the specific information using resources commonly set among multiple user terminals.

Description

Technical Field

[0001] The present disclosure relates to a user terminal and a wireless communication method in a next generation mobile communication system. Background Art

[0002] In the Universal Mobile Telecommunications System (UMTS) network, Long Term Evolution (LTE) has been standardized to achieve even higher data rates and lower latency (Non-Patent Document 1). Furthermore, LTE-Advanced (3GPP Rel. 10-14) has been standardized to further enhance the capacity and sophistication of LTE (Third Generation Partnership Project (3GPP) Releases (Rel.) 8 and 9).

[0003] Successor systems to LTE (for example, also referred to as fifth-generation mobile communication system (5G), 5G+ (plus), New Radio (NR), 3GPP Rel.15 and later, etc.) are also under study.

[0004] Prior art literature

[0005] Non-patent literature

[0006] Non-Patent Document 1: 3GPP TS 36.300 V8.12.0 “Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 8)”, April 2010. Summary of the Invention

[0007] Problems to be solved by the invention

[0008] It is envisioned that in future wireless communication systems (e.g., NR), as data transmission methods, unicast transmission that is performed individually to each user terminal (UE), broadcast transmission that is performed commonly to multiple UEs, and multicast transmission are supported.

[0009] Furthermore, support for retransmission control (e.g., HARQ) for at least one of broadcast and multicast transmissions in NR is also under study. However, how to control retransmission control for broadcast or multicast transmissions has not yet been fully studied.

[0010] Therefore, one of the objects of the present disclosure is to provide a user terminal and a wireless communication method capable of appropriately controlling retransmission control for at least one of broadcast transmission and multicast transmission.

[0011] Means for solving problems

[0012] A user terminal according to one embodiment of the present disclosure is characterized in that it includes: a receiving unit that receives specific information sent through at least one of broadcast and multicast; and a control unit that controls the reporting of retransmission control information for the specific information using resources commonly set among multiple user terminals.

[0013] Effects of the Invention

[0014] According to one aspect of the present disclosure, it is possible to appropriately control retransmission control for at least one of broadcast transmission and multicast transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a diagram showing an example of broadcast / multicast transmission.

[0016] Figure 2 This is a diagram showing an example of retransmission control according to the first example.

[0017] Figure 3 This is a diagram showing another example of retransmission control according to the first embodiment.

[0018] Figure 4 This is a diagram showing an example of retransmission control according to the second example.

[0019] Figure 5 This is a diagram showing an example of retransmission control according to the third example.

[0020] Figure 6 This is a diagram showing an example of retransmission control according to the fourth example.

[0021] Figure 7 This is a diagram showing another example of retransmission control according to the fourth example.

[0022] Figure 8 This is a diagram showing an example of a schematic configuration of a wireless communication system according to one embodiment.

[0023] Figure 9 This is a diagram showing an example of the configuration of a base station according to one embodiment.

[0024] Figure 10 This is a diagram showing an example of the configuration of a user terminal according to an embodiment.

[0025] Figure 11 This is a diagram showing an example of the hardware configuration of a base station and a user terminal according to one embodiment. DETAILED DESCRIPTION

[0026] It is envisioned that future wireless communication systems (e.g., NR) will support unicast transmission, broadcast transmission, and multicast transmission. In unicast transmission, data or channels can be transmitted individually (e.g., UE-specifically) to each UE. At least one of broadcast transmission and multicast transmission (hereinafter also referred to as broadcast / multicast transmission) can transmit data or channels in common to multiple UEs (e.g., a UE group).

[0027] Unicast transmission, broadcast transmission, and multicast transmission may each use a different channel (at least one of a logical channel and a physical channel). Alternatively, broadcast transmission and multicast transmission may use the same structure.

[0028] Broadcast / multicast transmission is an effective method for distributing the same information to multiple UEs (e.g., a specific UE group). Therefore, it is envisioned that broadcast / multicast transmission will be used to notify information related to public safety, such as the distribution of road conditions, traffic signs, and traffic light status, or intelligent transport systems (ITS). Alternatively, it is envisioned that broadcast / multicast transmission will be used to notify audiences at concerts or stadiums.

[0029] In NR, retransmission control (e.g., HARQ operation) for broadcast / multicast transmissions can also be considered. However, how to control retransmission control for broadcast / multicast transmissions has not been fully studied. Without appropriate retransmission control, communication quality, etc. may deteriorate.

[0030] The present inventors have studied retransmission control for broadcast / multicast transmission and have completed the present invention.

[0031] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Each embodiment may be applied individually or in combination. In the following description, HARQ-based retransmission is used as an example of retransmission control, but the present invention is not limited thereto.

[0032] In the following description, retransmission control for broadcast transmission may be renamed as retransmission control for information transmitted via broadcast. Information transmitted via broadcast may also be renamed as at least one of data, data channel, DL-SCH, broadcast channel, control information, DCI, control channel, and broadcast control information. Retransmission control for multicast transmission may be renamed as retransmission control for information transmitted via multicast. Information transmitted via multicast may also be renamed as at least one of data, data channel, DL-SCH, multicast channel, control information, DCI, control channel, and multicast control information.

[0033] Information sent by broadcast / multicast can be included in data (e.g., DL-SCH, shared channel, etc.) scheduled by downlink control information (e.g., DCI), can be included in DCI, can be sent by higher-layer signaling (e.g., at least one of RRC signaling and broadcast information), or can be sent by a dedicated signal or channel. In the case where the information sent by broadcast / multicast is included in the data, the DCI that schedules the data can also be sent by broadcast / multicast. In the following description, the description of sending by DCI or higher-layer signaling can also be set as applying at least one of unicast transmission (or UE-specific transmission) and broadcast / multicast transmission (or UE-common transmission).

[0034] (First Method)

[0035] The first approach describes retransmission control for broadcast / multicast transmission.

[0036] Figure 1 This example illustrates a scenario where a base station transmits specific information to multiple UEs (e.g., UE groups) using at least one of broadcast and multicast (hereinafter referred to as broadcast / multicast). This example illustrates a scenario where the base station broadcasts / multicasts to UE Group #1 and UE Group #2, respectively. The number of UE groups, the UEs that comprise each UE group, and other factors may be modified as appropriate.

[0037] Each UE can determine whether to support retransmission control for information transmitted by broadcast / multicast (or whether to apply retransmission control or whether to set retransmission control) based on specific information (see Figure 2The specific information may be information notified using at least one of higher layer signaling (option 1) and downlink control information (option 2) notified from the network (e.g., base station). Alternatively, the UE may determine whether to apply retransmission control based on a specific rule (option 3).

[0038] <Option 1>

[0039] The UE can determine whether to apply retransmission control to information transmitted via broadcast / multicast based on higher layer signaling. The base station can notify each UE of whether to apply retransmission control or each UE group using higher layer signaling.

[0040] When both broadcast transmission (e.g., transmission using a broadcast channel) and multicast transmission (e.g., transmission using a multicast channel) are supported, whether to apply retransmission control to broadcast transmission and whether to apply retransmission control to multicast transmission can be set separately. This allows for flexible control over whether to apply retransmission control.

[0041] Alternatively, when broadcast transmission and multicast transmission are supported separately, whether to apply retransmission control for broadcast transmission and whether to apply retransmission control for multicast transmission can be commonly configured. In this case, if the UE sets whether to apply retransmission control for one of broadcast transmission and multicast transmission, the UE can also apply the same setting to the other. As a result, the retransmission control configuration can be simplified.

[0042] <Option 2>

[0043] The UE may also determine whether to apply retransmission control for information sent via broadcast / multicast based on downlink control information (e.g., DCI, etc.). The base station may use UE-specific DCI to notify each UE whether to apply retransmission control, or may use group-common DCI to notify each UE group whether to apply retransmission control. For example, when information sent via broadcast / multicast is scheduled by DCI, information about HARQ-ACK (e.g., whether it is applied, at least one of the transmission timing and resources) may be included in the DCI.

[0044] When broadcast transmission and multicast transmission are supported separately, whether to apply retransmission control to broadcast transmission and whether to apply retransmission control to multicast transmission can be set separately. This allows flexible control of whether to apply retransmission control.

[0045] Alternatively, when both broadcast and multicast transmissions are supported, whether to apply retransmission control for broadcast transmission and whether to apply retransmission control for multicast transmission can be configured in common. In this case, if the application of retransmission control is configured for one of broadcast and multicast transmissions, the UE can also apply the same configuration to the other transmission. This simplifies the configuration of retransmission control.

[0046] <Option 3>

[0047] The UE may also implicitly determine whether to apply retransmission control for information transmitted via broadcast / multicast based on specific rules. The specific rules may also be specific conditions set during transmission or reception (e.g., transmission conditions used in broadcast / multicast transmission). The following describes a case where the specific condition is repeated transmission (Case 1) and a case where the specific condition is at least one of a modulation and coding scheme (MCS) and a coding rate (Case 2). Specific conditions are not limited to these.

[0048] [Case 1]

[0049] When repetition is applied to information sent via broadcast / multicast, the UE may determine that retransmission control (e.g., HARQ) is not supported or is not applied. Furthermore, the UE may determine that retransmission control is supported or is applied when repetition is not applied.

[0050] The UE may also determine whether to apply retransmission control based on the number of repetitions (also known as the repetition factor). For example, if the number of repetitions exceeds a specific value (e.g., X), the UE may not apply retransmission control. However, if the number of repetitions is less than the specific value, the UE may apply retransmission control. The specific value (e.g., X) may be predefined in the specification or notified to the UE by the base station through higher-layer signaling.

[0051] Whether to apply retransmission (or the number of retransmissions) can also be set for each UE group. Alternatively, retransmission (or the number of retransmissions) can be set for each UE. In the case of setting for each UE, whether to apply retransmission control can also be independently set for each UE included in the UE group.

[0052] [Case 2]

[0053] The UE can also determine whether to apply retransmission control for information transmitted via broadcast / multicast based on at least one of the MCS and coding rate applied to the information transmitted via broadcast / multicast (hereinafter, also referred to as MCS / coding rate).

[0054] For example, the UE can also not apply retransmission control when the MCS / coding rate corresponding to the information transmitted via broadcast / multicast is below a specific value (e.g., Y), and apply retransmission control otherwise (e.g., when the MCS / coding rate is greater than the specific value). The specific value (e.g., Y) can be predefined in the specification or can also be notified to the UE from the base station via higher layer signaling or the like.

[0055] In this way, by controlling whether to apply retransmission control for broadcast / multicast transmission based on specific conditions, it is possible to flexibly control retransmission control based on the communication environment or communication conditions.

[0056] <HARQ process>

[0057] In HARQ-based retransmission control, retransmission control of data (transport block (TB) or code block (CB)) is performed in units of processes (HARQ processes). In HARQ processes with the same number (HARQ process number (HPN)), the same data is retransmitted until an ACK is received. The HARQ process number is also referred to as the HARQ process ID (HARQ process identifier).

[0058] In one time interval (e.g., time slot or subframe), one HARQ process can be used, or multiple HARQ processes can be used. By independently and parallelly processing multiple HARQ processes, it is possible to transmit data of the next HARQ process without waiting for the A / N of the previous HARQ process, thereby reducing the latency time.

[0059] Retransmission control can also be performed based on HARQ processes in retransmission control for broadcast / multicast transmission. For example, X (or X number, X) (X≥1) HARQ processes can be set for the information transmitted via broadcast / multicast. X can be predefined in the specification or can also be notified to the UE from the base station via at least one of higher layer signaling and downlink control information.

[0060] In the case of separately supporting broadcast transmission and multicast transmission, X for broadcast transmission and X for multicast transmission can also be set separately. X for broadcast transmission and X for multicast transmission can also be set publicly. Alternatively, different X can be set for each broadcast transmission (or each multicast transmission).

[0061] In addition, it can be considered that the UE sends HARQ-ACK for unicast transmission and HARQ-ACK for broadcast / multicast transmission (see Figure 3 ). Figure 3 An example is shown in which the UE reports HARQ-ACK#B for broadcast / multicast transmission and HARQ-ACK#A for unicast transmission.

[0062] In this case, the HARQ process pool corresponding to information sent via unicast and the HARQ process pool corresponding to information sent via broadcast / multicast may be separately set. The HARQ process pool may be a processing operation of a HARQ process, or may be a value of a HARQ process number or a range of HARQ process numbers.

[0063] For example, the HARQ process number for unicast transmission (e.g., HARQ-ACK#B) and the HARQ process number for broadcast / multicast transmission (e.g., HARQ-ACK#A) may be set separately. The UE may also control retransmission of unicast transmission based on the HARQ process number for unicast transmission, and control retransmission of broadcast / multicast transmission based on the HARQ process number for broadcast / multicast transmission.

[0064] In this way, by distinguishing between information sent via unicast and information sent via broadcast / multicast and setting the HARQ process pool, it is possible to avoid conflicts between the HARQ process sent via unicast and the HARQ process sent via broadcast / multicast.

[0065] Alternatively, a HARQ process pool corresponding to information transmitted by unicast and a HARQ process pool corresponding to information transmitted by broadcast / multicast may be set to be shared.

[0066] In this case, a common HARQ process number (eg, X HARQ processes) may also be applied to the HARQ process for unicast transmission and the HARQ process for broadcast / multicast transmission.

[0067] The network (e.g., a base station) may also control HARQ process processing so that HARQ processes do not conflict between information transmitted via unicast and information transmitted via broadcast / multicast. For example, at least one of the base station and the UE may also control so that a HARQ process number allocated to one of unicast transmission and broadcast / multicast transmission is not allocated to the other.

[0068] Alternatively, a priority (e.g., a priority rule) may be set for each HARQ process, and retransmission control may be performed based on the priority when HARQ processes are duplicated. For example, broadcast / multicast transmission may be given a higher priority than unicast transmission. In the event of a conflict between a HARQ process corresponding to unicast transmission and a HARQ process corresponding to broadcast / multicast transmission, the UE may prioritize retransmission control over the HARQ process corresponding to broadcast / multicast transmission.

[0069] The priority of the HARQ process may also be set based on other conditions. For example, the priority of the HARQ process may be determined based on the service (or service type). As an example, the priority of the HARQ process corresponding to the first service type (e.g., URLLC) may be set higher than the priority of the HARQ process corresponding to the second service type (e.g., eMBB).

[0070] Furthermore, when the HARQ process number is 1 (X=1), the scheduling information may not include information specifying the HARQ process number. For example, when X=1, the field for HARQ process notification may be omitted from the DCI that schedules at least one of control information and data for multicast / broadcast transmission, or may be used for other purposes. In other cases (X>1), an n-bit (e.g., n=log2(X)) field may be provided in the DCI to indicate the HARQ process ID corresponding to the multicast / broadcast transmission.

[0071] <Soft Buffer>

[0072] The UE may also have a buffer (soft buffer) for temporarily storing received data that failed decoding. In the soft buffer, received data (eg, TB, code block, or code block group (CBG) containing more than one code block) may also be stored for each HPN.

[0073] Furthermore, the UE can also soft-combine received data (or retransmitted data) based on the same HPN that is repeatedly transmitted. Furthermore, the user terminal can soft-combine data stored in the soft buffer with received data from the same HPN. Soft combining involves assigning the same HPN to multiple data items generated from the same information bit sequence and transmitting them. The receiver then synthesizes the multiple data items from the same HPN.

[0074] Alternatively, the UE-side soft buffer for information transmitted via unicast and the UE-side soft buffer for information transmitted via broadcast / multicast can be shared. In this case, even if decoding of one of the transmissions fails continuously, the soft buffer can be used effectively.

[0075] Alternatively, it is possible to separately set the soft buffer on the UE side for information transmitted via unicast and the soft buffer on the UE side for information transmitted via broadcast / multicast. For example, in the UE, in addition to the soft buffer used in unicast transmission, a soft buffer for broadcast / multicast transmission can also be set. Thus, it is possible to prevent the failure of decoding of one transmission from affecting the soft buffer of the other transmission.

[0076] (Second method)

[0077] The second method describes the feedback control of the delivery confirmation signal (or also referred to as the retransmission control signal, HARQ-ACK) for broadcast / multicast transmission.

[0078] <HARQ-ACK transmission timing>

[0079] The UE feeds back the HARQ-ACK for information transmitted via broadcast / multicast at a specific timing (e.g., K1) (see Figure 4 ). In Figure 4 , it shows that the UE included in UE group #1 feeds back the HARQ-ACK at a specific timing (e.g., K , 22 , , 12 , Figure 4 , , , 11 , 21 ,

[0080] ,

[0083] , 11 , Figure 4 ,

[0081] ,

[0082] , K 12 ), and the UE included in UE group #2 feeds back the HARQ-ACK at a specific timing (e.g., K 21 , K <00​​​​​​​​​​​​​​​​​​​​​​​​​​​12 = fixed value K A , K 21 =K 22 = fixed value K B .

[0084] It is also possible to set the HARQ-ACK feedback timing (for example, the same value) in common for multiple UEs included in a predetermined UE group that receives information transmitted by broadcast / multicast. Figure 4 In, it can also be at least K 11 =K 12 , K 21 =K 22 Thus, the feedback timing of HARQ-ACK from multiple UEs included in a predetermined UE group can be aligned.

[0085] Alternatively, the HARQ-ACK feedback timing (e.g., different values) may be independently set for each of the multiple UEs included in the UE group. Figure 4 In the middle, it can also be at least K 11 ≠K 12 , K 21 ≠K 22 In this case, the HARQ-ACK feedback timing from multiple UEs included in a specific UE group can be dispersed. In addition, the same value can be set for some of the multiple UEs included in a specific group, and different values ​​can be set for other UEs.

[0086] [Option 2-2]

[0087] Alternatively, a configuration may be employed in which a set of HARQ-ACK transmission timing values ​​(also referred to as a combination of transmission timing values, multiple transmission timing candidates, or a transmission timing candidate set) is set for broadcast / multicast transmission, and a specific transmission timing value is selected from the set. The set of HARQ-ACK transmission timing values ​​may also be predefined in the specification, or may be notified to the UE from the base station using higher layer signaling or the like.

[0088] Furthermore, the base station may also send information to the UE for specifying a specific transmission timing value from a set of HARQ-ACK transmission timing values. For example, the base station may include information for specifying a specific transmission timing value in downlink control information and send it to the UE. The UE may also determine the HARQ-ACK transmission timing value based on the bit information included in the downlink control information.

[0089] Downlink control information (e.g., group common PDCCH) can also be sent to multiple UEs (e.g., UEs included in a specific group). In this case, all UEs included in a specific group can use the same timing to feedback HARQ-ACK.

[0090] [Option 2-3]

[0091] The base station can also set a first transmission timing parameter (e.g., offset (e.g., T_delta or ΔT)) of the HARQ-ACK transmission timing for each UE. For example, the base station can also use higher layer signaling, etc. to set the offset of the HARQ-ACK transmission timing to the UE. In this case, the offset can be set separately for each UE (e.g., different offsets), or the offset can be set for each group (e.g., an offset common to a specific group).

[0092] Furthermore, the base station can also use downlink control information, etc. to notify the UE of information about the second transmission timing parameter (e.g., the transmission timing of HARQ-ACK). For example, the base station can use DCI (or PDCCH) for scheduling broadcast / multicast transmission or group common DCI (or, group common PDCCH) to notify multiple UEs of the same transmission timing (e.g., K1). Or, the base station can use UE-specific DCI (or UE-specific PDCCH) to separately notify each UE of the transmission timing.

[0093] Each UE determines the HARQ-ACK transmission timing (e.g., K1 + T_delta) based on the first transmission timing parameter (e.g., T_delta) notified by higher layer signaling and the second transmission timing parameter (e.g., transmission timing K1) notified by DCI. Thus, by specifically notifying at least one of the first parameter and the second parameter (e.g., the offset) to the UE, even when the other is set to be UE group common, the transmission timing can be flexibly controlled among UEs.

[0094] In addition, the transmission timing of HARQ-ACK for unicast transmission and the transmission timing of HARQ-ACK for broadcast / multicast transmission can also be set separately (e.g., by using different methods). Thus, the feedback timing of HARQ-ACK can be flexibly controlled according to each transmission.

[0095] <HARQ-ACK Feedback Resource>

[0096] The UE may also determine at least one of the resource and format (hereinafter referred to as resource / format) to be used in feedback for HARQ-ACK sent for broadcast / multicast transmission based on specific information. For example, the UE may also apply any of the following options 3-1 to 3-3 to determine the resource / format to use for HARQ-ACK. Furthermore, any of the above options 2-1 to 2-3 may be applied to the HARQ-ACK transmission timing.

[0097] [Option 3-1]

[0098] The base station may also use higher-layer signaling to notify each UE of information about the resources / format of a specific channel (e.g., PUCCH) used in HARQ-ACK transmission. The resources / format of the PUCCH notified to each UE may also be separately set for each UE (e.g., different resources / formats may be set).

[0099] Alternatively, the base station may use higher-layer signaling to notify each UE group of information about the PUCCH resources / format used in HARQ-ACK transmission. In other words, the PUCCH resources / format may be configured per UE group. In this case, UEs in the same group may use the same resources / format for HARQ-ACK transmission.

[0100] In option 3-1, the UE can determine the resources / format to be used for HARQ-ACK transmission based on information notified through higher layer signaling (without using L1 signaling).

[0101] [Option 3-2]

[0102] The base station may also notify each UE of the parameters of the first resource / format using higher layer signaling. The parameters of the first resource / format may also be information related to a resource index (e.g., PUCCH_index) of a specific channel (e.g., PUCCH) used in HARQ-ACK transmission. The PUCCH resource index (e.g., a different resource index) may be set separately for each UE.

[0103] In addition, the base station may also configure multiple sets of PUCCH resources (also referred to as multiple PUCCH resource candidate sets) to the UE through higher-layer signaling. Furthermore, the base station may include information for specifying a specific set from the multiple sets in downlink control information and send it to the UE. The specific set may also be referred to as a parameter of the second resource / format.

[0104] For example, the base station may also use DCI (or PDCCH) for scheduling broadcast / multicast transmissions, or group-common DCI (or group-common PDCCH) to notify multiple UEs of a specific set. Alternatively, the base station may use UE-specific DCI (or UE-specific PDCCH) to separately notify each UE of a specific set.

[0105] Each UE may also determine the PUCCH resource / format based on the parameters of the first resource / format notified via higher-layer signaling and the parameters of the second resource / format specified using at least one of DCI and higher-layer signaling. For example, the UE determines the PUCCH resource / format from a set of specific PUCCH resources specified by the downlink control information based on the PUCCH resource index notified via higher-layer signaling.

[0106] By specifically notifying at least one of the first resource / format parameters and the second resource / format parameters (e.g., the PUCCH resource index) to the UE, different PUCCH resources can be used among UEs even when the other is set to be UE group-common.

[0107] [Option 3-3]

[0108] The base station may also set multiple PUCCH resources (also referred to as PUCCH resource candidates) for the UE via higher-layer signaling. Further, the base station may send downlink control information including information for specifying a specific PUCCH resource from the multiple PUCCH resources to the UE (e.g., multiple UEs included in a specific group). The downlink control information may also be DCI sent via group-common PDCCH, or may also be DCI for scheduling broadcast / multicast transmissions.

[0109] In this case, the same PUCCH resource may also be specified for multiple UEs included in a specific group.

[0110] (Third method)

[0111] The third method describes the transmission power control of the uplink channel (e.g., at least one of PUCCH and PUSCH) used in the transmission of HARQ-ACK for broadcast / multicast transmissions. In the following description, PUCCH is exemplified as the uplink channel used in the transmission of HARQ-ACK, but the same can be similarly applied to other uplink channels (e.g., PUSCH).

[0112]

[0113] In Rel. 15, the UE performs transmission power control (TPC) for each transmission opportunity i. Transmission opportunity i can also be a transmission opportunity for PUSCH, PUCCH, SRS, or PRACH. Transmission opportunity i can also be a time slot index n for the subcarrier spacing configuration μ within a frame with a system frame number (SFN). s,f μ , and the first codeword in the time slot (the index of the first codeword of the transmission opportunity i) S, and the number of consecutive codewords L are defined.

[0114] The transmission power of PUCCH is controlled based on the TPC command (value, increase / decrease value, correction value, indication value, etc.) indicated by the value of a specific field (also called TPC command field, first field, etc.) in DCI.

[0115] For example, regarding the transmission power (P) of the PUCCH in the transmission opportunity (transmission occasion, etc.) i of the BWP b of the carrier f of the cell c using the index I of the power control adjustment state, PUCCH,b,f,c (I,q u ,q d ,I)), can also be expressed by the following formula (1).

[0116] Here, the power control adjustment state may be configured as having multiple states (e.g., two states) or a single state using higher-layer parameters. Furthermore, when multiple power control adjustment states are configured, one of the multiple power control adjustment states may be identified using an index I (e.g., I∈{0,1}). The power control adjustment state may also be referred to as a PUCCH power control adjustment state, a first state, a second state, or the like.

[0117] Furthermore, the PUCCH transmission opportunity i is a specific period for transmitting the PUCCH, and may be composed of, for example, one or more symbols, one or more time slots, and the like.

[0118] [Number 1]

[0119] Formula (1)

[0120]

[0121] In formula (1), P CMAX,f,c (i) is, for example, the transmission power (also referred to as maximum transmission power, etc.) of the user terminal set for carrier f of cell c in transmission opportunity i. O_PUCCH,b,f,c (q u ) is, for example, a parameter related to the target reception power of BWP b set for carrier f of cell c in transmission opportunity i (for example, also referred to as a parameter related to transmission power offset, transmission power offset PO, or target reception power parameter, etc.).

[0122] M PUCCH RB,b,f,c (i) For example, PL is the number of resource blocks (bandwidth) allocated to the PUCCH for transmission opportunity i in uplink BWP b of carrier f with cell c and subcarrier spacing μ. b,f,c (q d ) For example, the index q of the reference signal of the downlink BWP used by the user terminal to associate with the uplink BWP of the carrier f of the cell c is d Calculated path loss.

[0123] Δ F_PUCCH (F) is a high-level parameter assigned to each PUCCH format. TF,b,f,c (i) is a transmission power adjustment component (offset) of the uplink BWP b for the carrier f of the cell c.

[0124] g b,f,c (i, I) represents the value of the TPC command for the power control adjustment state index I based on the uplink BWP of carrier f in cell c and transmission opportunity i (e.g., the power control adjustment state and the cumulative value of the TPC commands). For example, the cumulative value of the TPC command can also be expressed by a specific formula.

[0125] The TPC command may also be determined based on the value of a specific field (also referred to as a TPC command field, a first field, etc.) within the DCI used for scheduling PUSCH or PDSCH. Power control information may also be referred to as a TPC command (also referred to as a value, an increase or decrease value, a correction value, etc.).

[0126] In addition, equation (1) is merely an example and is not limited to this. The user terminal only needs to control the PUCCH transmit power based on at least one parameter illustrated in equation (1). Additional parameters may be included, or some parameters may be omitted. Furthermore, in equation (1), the PUCCH transmit power is controlled for each BWP of a carrier in a cell, but this is not a limitation. At least some of the cell, carrier, BWP, and power control adjustment state may also be omitted.

[0127] The UE applies a specific transmission power (or a specific transmission power parameter) to the PUCCH used in the feedback of the HARQ-ACK for broadcast / multicast transmission (see Figure 5 ).exist Figure 5 , it is shown that the UEs included in UE group #1 are transmitted by applying a specific transmission power (eg, P 11 、P 12 ) of the PUCCH feedback HARQ-ACK, the UEs included in UE group #2 apply a specific transmission power (e.g., P 21 、P 22 )’s PUCCH feedback HARQ-ACK situation.

[0128] The UE may also determine a specific transmit power based on specific information. For example, the UE may also apply any one of the following options 4-1 to 4-2 to determine the transmit power.

[0129] [Option 4-1]

[0130] The UE may also determine the PUCCH transmit power based on a parameter configured via higher layer signaling (also referred to as a transmit power parameter). The parameter configured via higher layer signaling may be a parameter included in equation (1) (e.g., a combination of P0 and α), or another parameter.

[0131] Furthermore, the transmission power parameters (e.g., different transmission power parameters) may be set separately for a plurality of UEs included in a specific UE group to which the same information is transmitted by broadcast / multicast transmission. In other words, the transmission power parameters may be set separately for each UE. For example, Figure 5 In the , P is set separately 11 and P 12 (Or, P 21 and P 22 ).

[0132] Furthermore, transmission power values ​​may be set separately for multiple UEs included in a specific UE group to which the same information is transmitted by broadcast / multicast transmission. This allows for flexible transmission power control, taking into account interference between different UEs.

[0133] [Option 4-2]

[0134] The base station may also use high-layer signaling to set a first transmit power parameter for each UE. The first transmit power parameter may be set commonly for multiple UEs (e.g., a UE group), or may be set separately for each UE (e.g., a different value). The first transmit power parameter may be, for example, a power offset (e.g., P_delta or P_delta). Δ ).

[0135] In addition, the base station may also notify the UE of the second transmit power parameter using at least one of higher layer signaling and DCI. The second parameter may also be a power control value (eg, P_M or P_M). M For example, the base station may also use higher layer signaling to set a set of second transmit power parameters (eg, multiple second parameter candidate values ​​or a second parameter candidate set) to the UE, and use DCI to notify the UE of a specific second parameter.

[0136] For example, the base station may also use DCI (or PDCCH) scheduled for broadcast / multicast transmission, or group-common DCI (or group-common PDCCH) to notify multiple UEs of a specific second parameter. Alternatively, the base station may use UE-specific DCI (or UE-specific PDCCH) to separately notify each UE of the specific second parameter.

[0137] Each UE may also adjust the transmit power of the PUCCH based on the first transmit power parameter notified through higher layer signaling and the second transmit power parameter (eg, P_delta+P_M) specified using at least one of DCI and higher layer signaling.

[0138] By specifically notifying the UE of at least one of the first and second transmit power parameters (for example, P_delta), different transmit powers can be used among the UEs even when the other parameter is set to be common to the UE group.

[0139] [Option 4-3]

[0140] Each UE may also adjust the transmit power of the PUCCH based on the TPC command. For example, in addition to option 4-1 or 4-2, the UE may also consider the TPC command to determine the transmit power of the PUCCH.

[0141] The TPC command may also be included in the DCI that is scheduled for broadcast / multicast transmission. Alternatively, the TPC command may be included in a different DCI than the DCI that is scheduled for broadcast / multicast transmission. The DCI that transmits the TPC command may also be sent as UE-specific DCI or as DCI common to a specific UE group (e.g., a group-common PDCCH).

[0142] (Fourth Method)

[0143] The fourth transmission describes the transmission control of HARQ-ACK for broadcast / multicast transmission.

[0144] In HARQ-based retransmission control, if the reception processing (e.g., decoding) of the data is successful, the UE sends an ACK, and if it fails, the UE sends a NACK. As retransmission control for information sent via broadcast / multicast, the UE can also apply any of the following options 5-1 to 5-2.

[0145] [Option 5-1]

[0146] The UE may also be controlled to report only one (e.g., NACK) as HARQ-ACK for broadcast / multicast transmission. For example, the UE may be controlled so that NACK is reported when the decoding process for information transmitted by broadcast / multicast fails, and ACK is not reported when the decoding process succeeds (see Figure 6 ).

[0147] exist Figure 6 , shows a case where a UE included in UE group #1 sends a NACK when decoding information transmitted via broadcast / multicast fails, and a UE included in UE group #2 sends a NACK when decoding information transmitted via broadcast / multicast fails. Alternatively, control can be performed so that an ACK is not sent when decoding is successful.

[0148] The base station may also determine that data reception is successful for UEs that do not report a NACK. NACK detection in the base station may also be based on power detection (also known as energy detection). For example, the base station may also use the same mechanism as the detection of scheduling requests (SRs) sent via the PUCCH to detect NACKs.

[0149] Furthermore, the resources for NACKs reported by each UE can also be commonly configured (shared) among multiple UEs. That is, a UE that sends a NACK for a broadcast / multicast transmission can also use the same UL channel resources (e.g., PUCCH resources) to send the NACK. The resources used for NACK reporting can also be defined in the specification or notified to each UE (or each UE group) from the base station using at least one of downlink control information and higher-layer signaling.

[0150] For example, in Figure 6In the embodiment, when multiple UEs included in UE group #1 send NACKs, they may use the same UL channel resources (e.g., resources with the same time domain and frequency domain) to send NACKs. Similarly, when multiple UEs included in UE group #2 send NACKs, they may use the same UL channel resources (e.g., resources with the same time domain and frequency domain) to send NACKs.

[0151] In this way, by commonly setting resources for NACK reporting for multiple UEs (for example, the same UE group), resource utilization efficiency can be improved.

[0152] The base station can also perform retransmission control (e.g., determine whether to retransmit) based on whether a NACK report is detected in resources intended for NACKs. For example, assume that the base station detects a NACK in resources assigned to UE Group #1. This means that at least one UE in UE Group #1 (the UE transmitting via broadcast / multicast) has failed decoding.

[0153] In this case, the base station can also retransmit information (e.g., transport blocks) via broadcast / multicast. The UE can also control whether to receive the retransmitted information based on its own reception status. For example, control can be performed so that UEs that report a NACK receive the retransmitted information. On the other hand, UEs that do not report a NACK (e.g., UEs that successfully decode) can skip receiving (e.g., decoding) the retransmitted information.

[0154] In this manner, by controlling whether to receive retransmitted information based on the reception conditions, it is possible to suppress an increase in the load of reception processing on the UE.

[0155] In addition, in the above description, the case where only NACK is reported is shown, but the present invention is not limited to this and a configuration where only ACK is transmitted may also be employed.

[0156] [Option 5-2]

[0157] The UE can control the HARQ-ACK for broadcast / multicast transmission to report only at least one of ACK and NACK. For example, the UE can control the HARQ-ACK to report a NACK if the decoding process fails for information transmitted via broadcast / multicast, and to report an ACK if the decoding process succeeds. Alternatively, the UE can control the HARQ-ACK to report a NACK if the decoding process fails, and not report an ACK if the decoding process succeeds, as in Option 5-1 above.

[0158] The resources used by each UE in reporting at least one of ACK and NACK (hereinafter, also referred to as ACK / NACK) may be separately set for each UE (eg, UE-specific) (see Figure 7 ).exist Figure 7 , illustrates a scenario where each UE in UE group #1 uses different resources to send ACK / NACK for broadcast / multicast transmissions, while each UE in UE group #2 uses different resources to send ACK / NACK for broadcast / multicast transmissions. Alternatively, a UE may report only a NACK (only in the event of a decoding failure).

[0159] In this manner, different ACK / NACK reporting resources (e.g., at least one different resource in the time domain, frequency domain, and code) may be configured for multiple UEs belonging to the same UE group. The ACK / NACK reporting resources may also be notified to each UE from the base station using at least one of downlink control information and higher layer signaling.

[0160] The base station may also perform retransmission control (e.g., determine whether to retransmit) for each UE based on whether an ACK / NACK is detected in the resources configured for each UE. For example, the base station may retransmit only to UEs that report a NACK. In this case, the base station may selectively retransmit retransmission information (e.g., transport blocks) for information transmitted via broadcast / multicast to specific UEs using unicast transmission.

[0161] This allows retransmission only to UEs that have failed to decode information transmitted via broadcast / multicast. As a result, UEs that have successfully decoded information do not need to receive retransmitted information, thereby suppressing an increase in the reception processing load on the UE.

[0162] Alternatively, the base station can determine the retransmission method based on the number of UEs that reported NACKs (or the number of UEs that reported ACKs). For example, if the number of UEs reporting NACKs exceeds a predetermined value (or the number of UEs reporting ACKs is less than a specific value), retransmission can be performed via broadcast / multicast. In this case, UEs that did not report NACKs (or those that reported ACKs) can skip receiving (e.g., decoding) the retransmitted information.

[0163] (Wireless Communication System)

[0164] The following describes a configuration of a wireless communication system according to an embodiment of the present disclosure. In this wireless communication system, communication is performed using any one of the wireless communication methods according to the above-described embodiments of the present disclosure, or a combination thereof.

[0165] Figure 8This figure shows an example of a schematic configuration of a wireless communication system according to one embodiment. The wireless communication system 1 may also be a system that implements communication using Long Term Evolution (LTE) standardized by the Third Generation Partnership Project (3GPP), the fifth generation mobile communication system New Radio (5G NR), or the like.

[0166] In addition, the wireless communication system 1 can also support dual connectivity between multiple radio access technologies (Radio Access Technologies) (RATs) (Multi-RAT Dual Connectivity (MR-DC)). MR-DC can also include dual connectivity between LTE (Evolved Universal Terrestrial Radio Access (E-UTRA)) and NR (E-UTRA-NR Dual Connectivity (EN-DC)), dual connectivity between NR and LTE (NR-E-UTRA Dual Connectivity (NR-E-UTRA Dual Connectivity (NE-DC)), etc.

[0167] In EN-DC, the LTE (E-UTRA) base station (eNB) is the master node (MN), and the NR base station (gNB) is the secondary node (SN). In NE-DC, the NR base station (gNB) is the MN, and the LTE (E-UTRA) base station (eNB) is the SN.

[0168] The wireless communication system 1 can also support dual connectivity between multiple base stations within the same RAT (for example, dual connectivity (NR-NR Dual Connectivity (NN-DC)) where both MN and SN are NR base stations (gNB)).

[0169] The wireless communication system 1 may also include a base station 11 that forms a macrocell C1 with relatively wide coverage, and base stations 12 (12a-12c) that are located within the macrocell C1 and form small cells C2 that are narrower than the macrocell C1. User terminals 20 may also be located within at least one of the cells. The arrangement and number of cells and user terminals 20 are not limited to those shown in the figure. Hereinafter, when not distinguishing between base stations 11 and 12, they are collectively referred to as base stations 10.

[0170] The user terminal 20 may be connected to at least one of the multiple base stations 10. The user terminal 20 may utilize at least one of carrier aggregation (CA) using multiple component carriers (CCs) and dual connectivity (DC).

[0171] Each CC may also be included in at least one of the first frequency band (Frequency Range 1 (FR1)) and the second frequency band (Frequency Range 2 (FR2)). The macro cell C1 may also be included in FR1, and the small cell C2 may also be included in FR2. For example, FR1 may be a frequency band below 6 GHz (sub-6 GHz), and FR2 may be a frequency band higher than 24 GHz (above-24 GHz). In addition, the frequency bands and definitions of FR1 and FR2 are not limited to this. For example, FR1 may also correspond to a frequency band higher than FR2.

[0172] Furthermore, the user terminal 20 may communicate in each CC using at least one of time division duplex (TDD) and frequency division duplex (FDD).

[0173] Multiple base stations 10 can also be connected via wired (for example, optical fiber based on Common Public Radio Interface (CPRI) or X2 interface) or wireless (for example, NR communication). For example, when NR communication is used as a backhaul between base stations 11 and 12, the base station 11 equivalent to the upper station can also be called an integrated access backhaul (IAB) donor, and the base station 12 equivalent to the relay station can also be called an IAB node.

[0174] The base station 10 may also be connected to the core network 30 via other base stations 10 or directly. The core network 30 may also include, for example, at least one of an Evolved Packet Core (EPC), a 5G Core Network (5GCN), and a Next Generation Core (NGC).

[0175] The user terminal 20 may also be a terminal that supports at least one of communication methods such as LTE, LTE-A, and 5G.

[0176] In the wireless communication system 1, a radio access scheme based on orthogonal frequency division multiplexing (OFDM) may be used. For example, in at least one of the downlink (DL) and uplink (UL), cyclic prefix OFDM (CP-OFDM), discrete Fourier transform spread OFDM (DFT-s-OFDM), orthogonal frequency division multiple access (OFDMA), or single carrier frequency division multiple access (SC-FDMA) may be used.

[0177] The radio access scheme may also be referred to as a waveform. In the wireless communication system 1, other radio access schemes (for example, other single-carrier transmission schemes, other multi-carrier transmission schemes) may be applied to the UL and DL radio access schemes.

[0178] In the wireless communication system 1, as downlink channels, a downlink shared channel (Physical Downlink Shared Channel (PDSCH)) shared by each user terminal 20, a broadcast channel (Physical Broadcast Channel (PBCH))), a downlink control channel (Physical Downlink Control Channel (PDCCH)), etc. can also be used.

[0179] In addition, in the wireless communication system 1, as uplink channels, an uplink shared channel (Physical Uplink Shared Channel (PUSCH)) shared by each user terminal 20, an uplink control channel (Physical Uplink Control Channel (PUCCH)), a random access channel (Physical Random Access Channel (PRACH)), etc. can also be used.

[0180] The PDSCH transmits user data, higher-layer control information, and system information blocks (SIBs). The PUSCH also transmits user data, higher-layer control information, and master information blocks (MIBs). The PBCH also transmits master information blocks (MIBs).

[0181] The lower layer control information may also be transmitted via the PDCCH. The lower layer control information may include, for example, downlink control information (Downlink Control Information (DCI)) including scheduling information for at least one of the PDSCH and the PUSCH.

[0182] In addition, the DCI that schedules the PDSCH may also be referred to as DL allocation, DL DCI, etc., and the DCI that schedules the PUSCH may also be referred to as UL grant, UL DCI, etc. In addition, the PDSCH may also be referred to as DL data, and the PUSCH may also be referred to as UL data.

[0183] In PDCCH detection, a control resource set (CORESET) and a search space can also be used. A CORESET corresponds to the resources for searching for DCI. A search space corresponds to the search area and search method for PDCCH candidates. A CORESET can also be associated with one or more search spaces. The UE can also monitor the CORESET associated with a search space based on the search space settings.

[0184] A search space may also correspond to PDCCH candidates corresponding to one or more aggregation levels. One or more search spaces may also be referred to as a search space set. Furthermore, the terms "search space," "search space set," "search space setting," "search space set setting," "CORESET," and "CORESET setting" in this disclosure may be interchangeably referred to.

[0185] Uplink control information (uplink control information (UCI)) including at least one of channel state information (CSI), delivery confirmation information (e.g., also known as hybrid automatic repeat request ACKnowledgement (HARQ-ACK), ACK / NACK, etc.), and scheduling request (SR) may also be transmitted via the PUCCH. A random access preamble used to establish a connection with a cell may also be transmitted via the PRACH.

[0186] In the present disclosure, downlink, uplink, etc. may be expressed without the word "link." Furthermore, various channels may be expressed without the word "physical" at the beginning.

[0187] In the wireless communication system 1, a synchronization signal (Synchronization Signal (SS)), a downlink reference signal (Downlink Reference Signal (DL-RS)), etc. may also be transmitted. In the wireless communication system 1, as DL-RS, a cell-specific reference signal (Cell-specific Reference Signal (CRS)), a channel state information reference signal (Channel State Information Reference Signal (CSI-RS)), a demodulation reference signal (DeModulation Reference Signal (DMRS)), a positioning reference signal (Positioning Reference Signal (PRS)), a phase tracking reference signal (Phase Tracking Reference Signal (PTRS)), etc. may also be transmitted.

[0188] The synchronization signal may be, for example, at least one of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS). A signal block including SSs (PSS, SSS) and PBCH (and DMRS for PBCH) may also be referred to as an SS / PBCH block, an SS block (SSB), or the like. Furthermore, SSs and SSBs may also be referred to as reference signals.

[0189] In addition, in the wireless communication system 1, as an uplink reference signal (UL-RS), a measurement reference signal (Sounding Reference Signal (SRS)), a demodulation reference signal (DMRS), etc. can also be transmitted. In addition, DMRS can also be called a user terminal specific reference signal (UE-specific Reference Signal).

[0190] (Base Station)

[0191] Figure 9 This figure shows an example of the configuration of a base station according to one embodiment. The base station 10 includes a control unit 110, a transmitting / receiving unit 120, a transmitting / receiving antenna 130, and a transmission path interface (transmission line interface) 140. Furthermore, more than one of each of the control unit 110, the transmitting / receiving unit 120, the transmitting / receiving antenna 130, and the transmission path interface 140 may be provided.

[0192] In addition, in this example, the functional blocks of the characteristic parts of this embodiment are mainly shown, and it is also conceivable that the base station 10 also has other functional blocks required for wireless communication. Part of the processing of each unit described below may also be omitted.

[0193] The control unit 110 controls the entire base station 10. The control unit 110 can be composed of a controller, a control circuit, and the like that are described based on the common knowledge in the technical field to which this disclosure relates.

[0194] The control unit 110 may also control signal generation, scheduling (e.g., resource allocation, mapping), etc. It may also control transmission and reception, measurement, etc., using the transmission and reception unit 120, the transmission and reception antennas 130, and the transmission path interface 140. The control unit 110 may also generate data, control information, sequences, etc. to be transmitted as signals, and forward them to the transmission and reception unit 120. The control unit 110 may also perform call processing (setting up, releasing, etc.) of communication channels, manage the status of the base station 10, manage radio resources, etc.

[0195] The transceiver unit 120 may also include a baseband unit 121, a radio frequency (RF) unit 122, and a measurement unit 123. The baseband unit 121 may also include a transmission processing unit 1211 and a reception processing unit 1212. The transceiver unit 120 may include a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter (phase shifter), a measurement circuit, a transceiver circuit, and the like, which are described based on the common knowledge in the technical field involved in this disclosure.

[0196] The transmitting and receiving unit 120 may be configured as an integrated transmitting and receiving unit, or may be configured as a transmitting unit and a receiving unit. The transmitting unit may also be configured as a transmitting processing unit 1211 and an RF unit 122. The receiving unit may also be configured as a receiving processing unit 1212, an RF unit 122, and a measuring unit 123.

[0197] The transmitting and receiving antenna 130 can be formed of an antenna described based on the common knowledge in the technical field to which this disclosure relates, such as an array antenna.

[0198] The transmitting and receiving unit 120 may also transmit the aforementioned downlink channel, synchronization signal, downlink reference signal, etc. The transmitting and receiving unit 120 may also receive the aforementioned uplink channel, uplink reference signal, etc.

[0199] The transmitting and receiving unit 120 may also use digital beamforming (eg, precoding), analog beamforming (eg, phase rotation), etc. to form at least one of a transmit beam and a receive beam.

[0200] The sending and receiving unit 120 (sending processing unit 1211) can also perform processing on the Packet Data Convergence Protocol (PDCP) layer, the Radio Link Control (RLC) layer (for example, RLC retransmission control), the Medium Access Control (MAC) layer (for example, HARQ retransmission control), etc. on the data and control information obtained from the control unit 110 to generate a bit string to be sent.

[0201] The transmitting and receiving unit 120 (transmitting processing unit 1211) can also perform channel coding (which may also include error correction coding), modulation, mapping, filter processing, discrete Fourier transform (DFT) processing (as needed), inverse fast Fourier transform (IFFT) processing, precoding, digital-to-analog conversion and other transmission processing on the bit string to be sent, and output a baseband signal.

[0202] The transmitting and receiving unit 120 (RF unit 122 ) may also perform modulation, filter processing, amplification, etc. on the baseband signal to a radio frequency band, and transmit the signal in the radio frequency band via the transmitting and receiving antenna 130 .

[0203] On the other hand, the transmitting and receiving unit 120 (RF unit 122 ) may also perform amplification, filter processing, and demodulation into a baseband signal on the radio frequency band signal received by the transmitting and receiving antenna 130 .

[0204] The transmitting and receiving unit 120 (receiving processing unit 1212) can also apply analog-to-digital conversion, fast Fourier transform (FFT) processing, inverse discrete Fourier transform (IDFT)) processing (as needed), filter processing, demapping, demodulation, decoding (which may also include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing to the obtained baseband signal to obtain user data, etc.

[0205] The transmitting and receiving unit 120 (measuring unit 123) may also perform measurements related to the received signal. For example, the measuring unit 123 may also perform radio resource management (RRM) measurements, channel state information (CSI) measurements, etc. based on the received signal. The measuring unit 123 may also measure received power (e.g., Reference Signal Received Power (RSRP)), received quality (e.g., Reference Signal Received Quality (RSRQ)), signal to interference plus noise ratio (SINR), signal to noise ratio (SNR)), signal strength (e.g., received signal strength indicator (RSSI)), propagation path information (e.g., CSI), etc. The measurement results may also be output to the control unit 110.

[0206] The transmission path interface 140 can also send and receive signals (return signaling) between the devices included in the core network 30, other base stations 10, etc., and can also obtain and transmit user data (user plane data) and control plane data for the user terminal 20.

[0207] In addition, the transmitting unit and the receiving unit of the base station 10 in the present disclosure may also be constituted by at least one of the transmitting and receiving unit 120 , the transmitting and receiving antenna 130 , and the transmission path interface 140 .

[0208] Furthermore, the transmitting and receiving unit 120 transmits the specific information by using at least one of broadcast and multicast. The transmitting and receiving unit 120 may also receive retransmission control information for the specific information transmitted by using at least one of broadcast and multicast.

[0209] The control unit 110 may also control to set, for the UE, whether to apply retransmission control to specific information transmitted by at least one of broadcast and multicast.

[0210] Furthermore, the control unit 110 may also perform control so as to set the transmission timing of retransmission control for specific information transmitted by at least one of broadcast and multicast to the UE.

[0211] Furthermore, the control unit 110 may also perform control so that the transmission power for retransmission control of specific information transmitted by utilizing at least one of broadcast and multicast is set to the UE.

[0212] Furthermore, the control unit 110 may also perform control so as to set resources for retransmission control of specific information transmitted by at least one of broadcast and multicast for the UE.

[0213] (User Terminal)

[0214] Figure 10 This figure shows an example of the configuration of a user terminal according to one embodiment. The user terminal 20 includes a control unit 210, a transmitting / receiving unit 220, and a transmitting / receiving antenna 230. Furthermore, the control unit 210, the transmitting / receiving unit 220, and the transmitting / receiving antenna 230 may each be provided in one or more units.

[0215] In addition, in this example, the functional blocks of the characteristic parts of this embodiment are mainly shown, and it is also assumed that the user terminal 20 also has other functional blocks required for wireless communication. Part of the processing of each unit described below may also be omitted.

[0216] The control unit 210 controls the entire user terminal 20. The control unit 210 can be composed of a controller, a control circuit, and the like that are described based on the common knowledge in the technical field to which this disclosure relates.

[0217] The control unit 210 may also control signal generation, mapping, etc. The control unit 210 may also control transmission, reception, measurement, etc. using the transmission and reception unit 220 and the transmission and reception antenna 230. The control unit 210 may also generate data, control information, sequences, etc. to be transmitted as signals and forward them to the transmission and reception unit 220.

[0218] The transceiver unit 220 may also include a baseband unit 221, an RF unit 222, and a measurement unit 223. The baseband unit 221 may also include a transmission processing unit 2211 and a reception processing unit 2212. The transceiver unit 220 may include a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transceiver circuit, and the like, which are described based on the common knowledge in the technical field involved in this disclosure.

[0219] The transmitting and receiving unit 220 may be configured as an integrated transmitting and receiving unit, or may be configured as a transmitting unit and a receiving unit. The transmitting unit may also be configured as a transmitting processing unit 2211 and an RF unit 222. The receiving unit may also be configured as a receiving processing unit 2212, an RF unit 222, and a measuring unit 223.

[0220] The transmitting and receiving antenna 230 can be formed of an antenna described based on the common knowledge in the technical field to which this disclosure relates, such as an array antenna.

[0221] The transmitting and receiving unit 220 may also receive the aforementioned downlink channel, synchronization signal, downlink reference signal, etc. The transmitting and receiving unit 220 may also transmit the aforementioned uplink channel, uplink reference signal, etc.

[0222] The transmitting and receiving unit 220 may also use digital beamforming (eg, precoding), analog beamforming (eg, phase rotation), etc. to form at least one of a transmitting beam and a receiving beam.

[0223] The sending and receiving unit 220 (sending processing unit 2211) can also perform PDCP layer processing, RLC layer processing (for example, RLC retransmission control), MAC layer processing (for example, HARQ retransmission control), etc. on the data, control information, etc. obtained from the control unit 210 to generate a bit string to be sent.

[0224] The transmitting and receiving unit 220 (transmitting processing unit 2211) can also perform channel coding (which may also include error correction coding), modulation, mapping, filter processing, DFT processing (as needed), IFFT processing, precoding, digital-to-analog conversion and other transmission processing on the bit string to be sent, and output a baseband signal.

[0225] In addition, whether DFT processing is applied may also be based on the setting of transform precoding. For a certain channel (e.g., PUSCH), if transform precoding is activated (enabled), the transmitting and receiving unit 220 (transmitting processing unit 2211) may also perform DFT processing as the above-mentioned transmission processing in order to transmit the channel using a DFT-s-OFDM waveform. Otherwise, the transmitting and receiving unit 220 (transmitting processing unit 2211) may also perform the above-mentioned transmission processing without performing DFT processing.

[0226] The transmitting and receiving unit 220 (RF unit 222 ) may also perform modulation, filter processing, amplification, etc. on the baseband signal to a radio frequency band, and transmit the signal in the radio frequency band via the transmitting and receiving antenna 230 .

[0227] On the other hand, the transmitting and receiving unit 220 (RF unit 222 ) may also perform amplification, filter processing, and demodulation into a baseband signal on the radio frequency band signal received by the transmitting and receiving antenna 230 .

[0228] The transmitting and receiving unit 220 (receiving processing unit 2212) can also apply receiving processing such as analog-to-digital conversion, FFT processing, IDFT processing (as needed), filter processing, demapping, demodulation, decoding (which may also include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing to the obtained baseband signal to obtain user data, etc.

[0229] The transmitting and receiving unit 220 (measuring unit 223) may also perform measurements related to received signals. For example, the measuring unit 223 may also perform RRM measurements, CSI measurements, etc. based on the received signals. The measuring unit 223 may also measure received power (e.g., RSRP), received quality (e.g., RSRQ, SINR, SNR), signal strength (e.g., RSSI), propagation path information (e.g., CSI), etc. The measurement results may also be output to the control unit 210.

[0230] In addition, the transmitting unit and the receiving unit of the user terminal 20 in the present disclosure may also be constituted by at least one of the transmitting and receiving unit 220 and the transmitting and receiving antenna 230 .

[0231] In addition, the transmitting and receiving unit 220 receives specific information transmitted by at least one of broadcast and multicast. In addition, the transmitting and receiving unit 220 can transmit retransmission control information for the specific information transmitted by at least one of broadcast and multicast.

[0232] Control unit 210 may also determine whether to transmit retransmission control information for specific information based on at least one of information sent from the network and conditions applied to the transmission of the specific information. For example, control unit 210 may determine whether to transmit retransmission control information for specific information based on at least one of whether repeated transmission of the specific information is applied, the MCS applied to the specific information, and the coding rate applied to the specific information. Furthermore, control unit 210 may also assume that the process number used in retransmission control for specific information and the process number used in retransmission control for information transmitted via unicast are commonly set. Furthermore, control unit 210 may also assume that the process number used in retransmission control for specific information and the process number used in retransmission control for information transmitted via unicast are separately set.

[0233] The control unit 210 may also determine the transmission timing of the retransmission control information for specific information based on at least one of a predefined value and information sent from the network. In addition, the control unit 210 may also select a specific transmission timing based on information related to a candidate set of transmission timings for the retransmission control information for the specific information and downlink control information that is commonly transmitted to a specific user terminal. In addition, the control unit 210 may also determine the transmission timing of the retransmission control information for the specific information based on a first transmission timing parameter notified by higher layer signaling and a second transmission timing parameter notified by downlink control information. In addition, the control unit 210 may also determine the resources to be used in transmitting the retransmission control information for the specific information based on a first resource parameter notified by higher layer signaling and a second resource parameter specified by at least one of higher layer signaling and downlink control information. In addition, the control unit 210 may also select a specific resource based on a candidate set of resources to be used in transmitting the retransmission control information for the specific information and downlink control information that is commonly transmitted to a specific user terminal.

[0234] The control unit 210 may also determine the transmit power of the uplink channel to be used for transmitting retransmission control information for specific information based on a transmit power parameter notified individually to each user terminal. Furthermore, the control unit 210 may also configure at least one of the transmit power parameter value and the transmit timing of the retransmission control information separately for each user terminal. Furthermore, the control unit 210 may determine the transmit power based on a first transmit power parameter notified via higher layer signaling and a second transmit power parameter specified via at least one of higher layer signaling and downlink control information. Furthermore, the control unit 210 may determine the transmit power based on a transmit power control command included in downlink control information different from the downlink control information used to schedule the specific information.

[0235] The control unit 210 may also control the reporting of retransmission control information for specific information using resources that are commonly configured between multiple user terminals. Furthermore, the control unit 210 may also control the reporting of only one of ACK and NACK as retransmission control information. Furthermore, when retransmission of specific information is sent via broadcast and multicast, the control unit 210 may also decide whether to receive the retransmitted information based on the specific information reception result. Furthermore, the control unit 210 may also control the reporting of retransmission control information for specific information using resources that are separately configured between user terminals. Furthermore, the control unit 210 may also assume that retransmission of specific information is sent via unicast.

[0236] (Hardware Structure)

[0237] In addition, the block diagrams used in the description of the above embodiments show blocks of functional units. These functional blocks (structural units) are implemented by any combination of at least one of hardware and software. In addition, the implementation method of each functional block is not particularly limited. That is, each functional block can be implemented by a device that is physically or logically combined, or two or more physically or logically separated devices can be directly or indirectly connected (for example, by wired, wireless, etc.) and implemented by these multiple devices. The functional block can also be implemented by combining the above-mentioned one device or the above-mentioned multiple devices with software.

[0238] Here, the functions include judging, deciding, determining, calculating, calculating, processing, deriving, investigating, searching, confirming, receiving, sending, outputting, accessing, resolving, selecting, selecting, establishing, comparing, assuming, expecting, regarding, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, assigning, etc., but are not limited to these. For example, a functional block (structural unit) that implements a sending function may also be referred to as a transmitting unit, a transmitter, etc. Any of these functions are as described above, and the implementation method is not particularly limited.

[0239] For example, a base station, a user terminal, etc. in one embodiment of the present disclosure may also function as a computer that performs processing of the wireless communication method of the present disclosure. Figure 11 This figure shows an example of the hardware configuration of a base station and a user terminal according to one embodiment. The base station 10 and user terminal 20 described above may also be physically configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like.

[0240] In addition, in this disclosure, terms such as device, circuit, equipment, section, and unit are interchangeable. The hardware configuration of the base station 10 and the user terminal 20 may include one or more of the devices shown in the figures, or may exclude some of the devices.

[0241] For example, although only one processor 1001 is shown, multiple processors may be provided. Furthermore, a single processor may perform processing, or two or more processors may perform processing simultaneously, sequentially, or using other methods. Furthermore, processor 1001 may be implemented using more than one chip.

[0242] Regarding the various functions in the base station 10 and the user terminal 20, for example, they are achieved by reading specific software (program) into hardware such as the processor 1001 and the memory 1002, so that the processor 1001 performs calculations and controls communication via the communication device 1004, or controls at least one of the reading and writing of data in the memory 1002 and the storage 1003.

[0243] The processor 1001 controls the entire computer by, for example, operating an operating system. The processor 1001 may also be composed of a central processing unit (CPU) including an interface with peripheral devices, a control device, a computing device, registers, etc. For example, at least a portion of the aforementioned control unit 110 (210) and the transmitting and receiving unit 120 (220) may also be implemented by the processor 1001.

[0244] In addition, the processor 1001 reads a program (program code), a software module, data, etc. from at least one of the storage 1003 and the communication device 1004 into the memory 1002 and performs various processes based on the program. As a program, a program that causes a computer to perform at least a portion of the operations described in the above embodiments can be used. For example, the control unit 110 (210) can also be implemented by a control program stored in the memory 1002 and operated by the processor 1001, and the other functional blocks can also be implemented similarly.

[0245] The memory 1002 may also be a computer-readable recording medium, for example, composed of 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), or other appropriate storage medium. The memory 1002 may also be referred to as a register, a cache, a main memory (main storage device), etc. The memory 1002 can store executable programs (program code), software modules, etc. for implementing the wireless communication method involved in one embodiment of the present disclosure.

[0246] The storage 1003 may also be a computer-readable recording medium, such as a flexible disk, a floppy disk, an optical disk (such as a compact disk (Compact Disc ROM (CD-ROM)), etc.), a digital versatile disk, a Blu-ray disk, a removable disk, a hard disk drive, a smart card, a flash memory device (such as a card, a stick, or a key drive), a magnetic stripe, a database, a server, or other appropriate storage media. The storage 1003 may also be referred to as an auxiliary storage device.

[0247] The communication device 1004 is hardware (a transmitting and receiving device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as a network device, a network controller, a network card, a communication module, or the like. To implement at least one of frequency division duplex (FDD) and time division duplex (TDD), the communication device 1004 may also be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, and the like. For example, the aforementioned transmitting and receiving unit 120 (220), transmitting and receiving antenna 130 (230), and the like may also be implemented by the communication device 1004. The transmitting and receiving unit 120 (220) may also be physically or logically separated from the transmitting unit 120a (220a) and the receiving unit 120b (220b).

[0248] The input device 1005 is an input device that receives input from the outside (e.g., a keyboard, mouse, microphone, switch, button, sensor, etc.). The output device 1006 is an output device that outputs to the outside (e.g., a display, speaker, light emitting diode (LED) lamp, etc.). Alternatively, the input device 1005 and the output device 1006 may be integrated (e.g., a touch panel).

[0249] Furthermore, the processor 1001, memory 1002, and other devices are connected via a bus 1007 for communicating information. The bus 1007 may be configured as a single bus or may be configured as different buses between the devices.

[0250] Furthermore, the base station 10 and user terminal 20 may also 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 may use this hardware to implement part or all of each functional block. For example, the processor 1001 may be implemented using at least one of these hardware components.

[0251] (Variation)

[0252] In addition, the terms described in this disclosure and the terms required for understanding this disclosure may also be replaced with terms having the same or similar meanings. For example, channels, code elements, and signals (signals or signaling) may also be referred to as one another. In addition, a signal may also be a message. A reference signal may also be referred to as RS, or may be referred to as a pilot, pilot signal, etc. depending on the applied standard. In addition, a component carrier (CC) may also be referred to as a cell, frequency carrier, carrier frequency, etc.

[0253] A radio frame can also be composed of one or more time periods (frames) in the time domain. The one or more time periods (frames) that constitute a radio frame can also be called a subframe. Furthermore, a subframe can also be composed of one or more time slots in the time domain. A subframe can also be a fixed time length (e.g., 1 ms) that is independent of the parameter set (numerology).

[0254] Here, a parameter set may also refer to communication parameters applied to at least one of the transmission and reception of a signal or channel. For example, a parameter set may also represent at least one of subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), the number of symbols per TTI, radio frame structure, specific filtering processing performed by the transmitter and receiver in the frequency domain, specific windowing processing performed by the transmitter and receiver in the time domain, and the like.

[0255] A time slot may also be composed of one or more symbols (Orthogonal Frequency Division Multiplexing (OFDM) symbols, Single Carrier Frequency Division Multiple Access (SC-FDMA) symbols, etc.) in the time domain. In addition, a time slot may also be a time unit based on a parameter set.

[0256] A time slot may also contain multiple mini-slots. Each mini-slot may also be composed of one or more symbols in the time domain. Furthermore, a mini-slot may also be referred to as a sub-slot. A mini-slot may also be composed of fewer symbols than a time slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a mini-slot may also be referred to as PDSCH (PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a mini-slot may also be referred to as PDSCH (PUSCH) mapping type B.

[0257] Radio frames, subframes, time slots, mini-slots, and symbols all represent time units used for signal transmission. Radio frames, subframes, time slots, mini-slots, and symbols may also be referred to by their respective names. Furthermore, in this disclosure, time units such as frames, subframes, time slots, mini-slots, and symbols may also be referred to interchangeably.

[0258] For example, a subframe can also be called a TTI, multiple consecutive subframes can also be called a TTI, and a time slot or a mini-time slot can also be called a TTI. In other words, at least one of the subframe and the TTI can be a subframe (1ms) in existing LTE, a period shorter than 1ms (for example, 1-13 symbols), or a period longer than 1ms. In addition, the unit representing the TTI can also be called a time slot, a mini-time slot, etc. instead of a subframe.

[0259] Here, TTI refers to, for example, the minimum time unit for scheduling in wireless communications. For example, in the LTE system, a base station schedules each user terminal by allocating radio resources (such as the frequency bandwidth and transmit power available to each user terminal) in TTI units. The definition of TTI is not limited to this.

[0260] The TTI can also be the time unit for transmitting channel-coded data packets (transport blocks), code blocks, code words, etc., and can also be the processing unit for scheduling, link adaptation, etc. In addition, when a TTI is given, the time interval (for example, the number of symbols) to which the transport blocks, code blocks, code words, etc. are actually mapped can be shorter than the TTI.

[0261] Furthermore, when a time slot or a mini-time slot is referred to as a TTI, one or more TTIs (i.e., one or more time slots or one or more mini-time slots) may also be the minimum time unit for scheduling. Furthermore, the number of time slots (mini-time slots) that constitute this minimum time unit for scheduling may also be controlled.

[0262] A TTI having a time length of 1 ms may also be referred to as a normal TTI (TTI in 3GPP Rel. 8-12), a standard TTI, a long TTI, a normal subframe, a standard subframe, a long subframe, a time slot, etc. A TTI shorter than a normal TTI may also be referred to as a shortened TTI, a short TTI, a partial TTI (partial or fractional TTI), a shortened subframe, a short subframe, a mini-slot, a subslot, a time slot, etc.

[0263] In addition, long TTI (for example, normal TTI, subframe, etc.) can also be renamed as TTI with a time length exceeding 1ms, and short TTI (for example, shortened TTI, etc.) can also be renamed as TTI with a TTI length smaller than long TTI and greater than 1ms.

[0264] A resource block (RB) is a unit of resource allocation in the time and frequency domains. In the frequency domain, it may also include one or more consecutive subcarriers (subcarriers). The number of subcarriers included in an RB can also be the same regardless of the parameter set, for example, it can be 12. The number of subcarriers included in an RB can also be determined based on the parameter set.

[0265] In addition, an RB may also include one or more symbols in the time domain, and may also be the length of a slot, a mini-slot, a subframe, or a TTI. A TTI, a subframe, etc. may also be composed of one or more resource blocks.

[0266] In addition, one or more RBs may also be referred to as a physical resource block (Physical RB (PRB)), a sub-carrier group (Sub-Carrier Group (SCG)), a resource element group (Resource Element Group (REG)), a PRB pair, an RB pair, etc.

[0267] 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.

[0268] A Bandwidth Part (BWP) (also referred to as a fractional bandwidth) can also represent a subset of contiguous common resource blocks (RBs) used for a parameter set within a carrier. Common RBs can also be identified by their index relative to the common reference point of the carrier. PRBs can also be defined within a BWP and numbered within that BWP.

[0269] The BWP may include a UL BWP (BWP for UL) and a DL BWP (BWP for DL). For a UE, one or more BWPs may be configured within one carrier.

[0270] At least one of the configured BWPs may be activated, and the UE may not assume that it will transmit or receive specific signals / channels outside of the activated BWP. In addition, "cell," "carrier," etc. in this disclosure may also be referred to as "BWP."

[0271] The above-described structures of radio frames, subframes, slots, mini-slots, and symbols are merely examples. For example, various modifications may be made to the number of subframes in a radio frame, the number of slots per subframe or radio frame, the number of mini-slots within a slot, the number of symbols and RBs within a slot or mini-slot, the number of subcarriers within an RB, the number of symbols within a TTI, the symbol length, and the cyclic prefix (CP) length.

[0272] Furthermore, the information and parameters described in this disclosure may be expressed as absolute values, relative values ​​relative to a specific value, or other corresponding information. For example, wireless resources may be indicated by specific indexes.

[0273] In this disclosure, the names used for parameters, etc., are not intended to be limiting in any respect. Furthermore, the mathematical formulas for these parameters, etc., may differ from those explicitly disclosed in this disclosure. Various channels (PUCCH, PDCCH, etc.) and information elements can 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 respect.

[0274] Information, signals, and the like described in this disclosure may also be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, and the like that may be referred to throughout the foregoing description may also be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any combination thereof.

[0275] Furthermore, information, signals, etc. can be output in at least one direction: from a higher layer (upper layer) to a lower layer (lower layer), and from a lower layer to a higher layer. Information, signals, etc. can also be input and output via multiple network nodes.

[0276] Input and output information, signals, etc. can be stored in a specific location (e.g., memory) or managed using a management table. Input and output information, signals, etc. can be overwritten, updated, or appended. Output information, signals, etc. can also be deleted. Input information, signals, etc. can also be sent to other devices.

[0277] The notification of information is not limited to the methods / implementations described in the present disclosure, and may also be performed by other methods. For example, the notification of information in the present disclosure may also be implemented through physical layer signaling (e.g., downlink control information (Downlink Control Information (DCI))), uplink control information (Uplink Control Information (UCI))), high-layer signaling (e.g., Radio Resource Control (RRC)) signaling, broadcast information (Master Information Block (MIB)), System Information Block (SIB), etc.), Medium Access Control (MAC) signaling), other signals, or a combination thereof.

[0278] In addition, physical layer signaling may also be referred to as Layer 1 / Layer 2 (L1 / L2) control information (L1 / L2 control signal), L1 control information (L1 control signal), etc. In addition, RRC signaling may also be referred to as RRC message, for example, it may also be an RRC Connection Setup message, an RRC Connection Reconfiguration message, etc. In addition, MAC signaling may also be notified using, for example, a MAC Control Element (CE).

[0279] Furthermore, notification of specific information (eg, notification of “it is X”) is not limited to explicit notification, but may be performed implicitly (eg, by not notifying the specific information or by notifying other information).

[0280] The judgment can be made by a value represented by a bit (0 or 1), a true or false value (Boolean value) represented by true (true) or false (false), or by comparing numerical values ​​(for example, comparing with a specified value).

[0281] Whether software is called software, firmware, middleware, microcode, hardware description language, or other names, it should be broadly interpreted as meaning instructions, instruction sets, code, code segments, program code, program, sub-program, software module, application, software application, software package, routine, sub-routine, object, executable file, execution thread, procedure, function, etc.

[0282] Furthermore, software, instructions, information, and the like may also be transmitted and received via a transmission medium. For example, if the software is transmitted from a website, server, or other remote source using at least one of a wired technology (coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), etc.) and a wireless technology (infrared, microwave, etc.), at least one of these wired and wireless technologies is included within the definition of a transmission medium.

[0283] The terms "system" and "network" used in this disclosure can be used interchangeably. "Network" may also refer to devices included in the network (eg, base stations).

[0284] In the present disclosure, terms such as "precoding", "precoder", "weight (precoding weight)", "Quasi-Co-Location (QCL)" "Transmission Configuration Indication state (TCI state)", "spatial relation", "spatial domain filter", "transmission power", "phase rotation", "antenna port", "antenna port group", "layer", "number of layers", "rank", "resource", "resource set", "resource group", "beam", "beam width", "beam angle", "antenna", "antenna element", and "panel" can be used interchangeably.

[0285] In this disclosure, terms such as "base station (BS)", "wireless base station", "fixed station", "NodeB", "eNB (eNodeB)", "gNB (gNodeB)", "access point", "transmission point (TP)", "reception point (RP)", "transmission / reception point (TRP)")", "panel", "cell", "sector", "cell group", "carrier", and "component carrier" are used interchangeably. In some cases, a base station may be referred to as a macro cell, a small cell, a femto cell, or a pico cell.

[0286] A base station can accommodate one or more (for example, three) cells. When a base station accommodates multiple cells, the overall coverage area of ​​the base station can be divided into multiple smaller areas, each of which can also provide communication services through a base station subsystem (for example, a small base station for indoor use (Remote Radio Head (RRH))). Terms such as "cell" or "sector" refer to a part or the entire coverage area of ​​at least one of a base station and a base station subsystem that provides communication services within that coverage area.

[0287] In the present disclosure, terms such as “Mobile Station (MS)”, “user terminal”, “User Equipment (UE)”, and “terminal” are used interchangeably.

[0288] A mobile station is also sometimes referred to as a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other appropriate terminology.

[0289] At least one of the base station and the mobile station may also be referred to as a transmitting device, a receiving device, a wireless communication device, etc. Furthermore, at least one of the base station and the mobile station may also be a device mounted on a mobile object, the mobile object itself, etc. The mobile object may be a vehicle (e.g., a car, an airplane, etc.), a mobile object that moves unmanned (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). Furthermore, at least one of the base station and the mobile station also includes a device that does not necessarily move when performing communication operations. For example, at least one of the base station and the mobile station may also be an Internet of Things (IoT) device such as a sensor.

[0290] In addition, the base station in the present disclosure may also be referred to as a user terminal. For example, the various methods / implementations of the present disclosure may also be applied to a structure in which the communication between a base station and a user terminal is replaced by the communication between multiple user terminals (for example, it may also be referred to as device-to-device (D2D)), vehicle-to-everything (V2X), etc.). In this case, it may also be a structure in which the user terminal 20 has the functions of the above-mentioned base station 10. In addition, expressions such as "uplink" and "downlink" may also be referred to as expressions corresponding to inter-terminal communication (for example, "side"). For example, uplink channels, downlink channels, etc. may also be referred to as side channels.

[0291] Likewise, the user terminal in the present disclosure may be referred to as a base station. In this case, the base station 10 may have the functions of the user terminal 20 described above.

[0292] In the present disclosure, operations are assumed to be performed by a base station, and sometimes, depending on the circumstances, by its upper node. Obviously, in a network including one or more network nodes including a base station, various operations performed for communication with a terminal may also be performed by the base station, one or more network nodes other than the base station (for example, a Mobility Management Entity (MME)), a Serving-Gateway (S-GW), etc., but not limited to these), or a combination thereof.

[0293] The various methods / implementations described in this disclosure may be used individually or in combination, and may be switched between them during execution. Furthermore, the processing procedures, sequences, flow charts, and the like of the various methods / implementations described in this disclosure may be reversed as long as they do not conflict. For example, the elements of various steps described in this disclosure are presented in an illustrative order, but are not limited to the specific order presented.

[0294] The various modes and embodiments described in the present disclosure may also be applied to Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), Future Radio Access (FRA), New Radio Access Technology (RAT), New Radio (NR), New Radio Access (NX), Future Generation Radio Access (FX), Global System for Mobile communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.17 (WiMAX (registered trademark)), IEEE 802.18 (WiMAX (registered trademark)), IEEE 802.19 (WiMAX (registered trademark)), IEEE 802.20 (WiMAX (registered trademark)), IEEE 802.21 (WiMAX (registered trademark)), IEEE 802.22 (WiMAX (registered trademark)), IEEE 802.23 (WiMAX (registered trademark)), IEEE 802.24 (WiMAX (registered trademark)), IEEE 802.25 (WiMAX (registered trademark)), IEEE 802.26 (WiMAX (registered trademark)), IEEE 802.27 (WiMAX (registered trademark)), IEEE 802.28 (WiMAX (registered trademark)), IEEE 802.29 (WiMAX (registered trademark)), IEEE 802.30 (WiMAX (registered trademark)), IEEE 802.31 (WiMAX (registered trademark)), IEEE 802.32 (WiMAX (registered trademark)), IEEE 802.33 (WiMAX (registered trademark)), IEEE 80 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), systems using other appropriate wireless communication methods, and next-generation systems based on these. In addition, multiple systems can also be combined for application (for example, LTE or LTE-A combined with 5G, etc.).

[0295] The phrase “based on” used in this disclosure does not mean “based only on” unless otherwise specified. In other words, the phrase “based on” means both “based only on” and “based at least on.”

[0296] Any reference to an element using the designations "first," "second," etc., as used in this disclosure, does not necessarily define the quantity or order of these elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Therefore, reference to a first and a second element does not necessarily imply that only two elements may be used, or that the first element necessarily takes precedence over the second element in some manner.

[0297] The term "determining" as used in this disclosure may encompass a variety of operations. For example, "determining" may also be considered as "judging," calculating, computing, processing, deriving, investigating, looking up (e.g., searching in a table, database, or other data structure), ascertaining, etc.

[0298] In addition, "judgment (decision)" can also be regarded as a situation of "judgment (decision)" on receiving (for example, receiving information), transmitting (for example, sending information), input (input), output (output), accessing (for example, accessing data in a memory), etc.

[0299] In addition, "judgment (decision)" can also be regarded as a situation in which "judgment (decision)" is performed on resolving, selecting, choosing, establishing, comparing, etc. In other words, "judgment (decision)" can also be regarded as a situation in which "judgment (decision)" is performed on some operations.

[0300] In addition, "judgment (decision)" can also be changed to "assuming (assuming)", "expecting (expecting)", "considering (considering)", etc.

[0301] The "maximum transmit power" recorded in this disclosure may refer to the maximum value of the transmit power, the nominal maximum transmit power (the nominal UE maximum transmit power), or the rated maximum transmit power (the rated UE maximum transmit power).

[0302] As used in this disclosure, the terms "connected," "coupled," or any variations 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 the two elements being "connected" or "coupled." The coupling or connection between elements may be physical, logical, or a combination thereof. For example, "connection" may also be referred to as "access."

[0303] In the present disclosure, when two elements are connected, it can be considered that they are "connected" or "combined" to each other using one or more wires, cables, printed electrical connections, etc., and as a non-limiting and non-inclusive example, electromagnetic energy with a wavelength in the wireless frequency domain, microwave region, light (both visible and invisible) region, etc.

[0304] In the present disclosure, the term "A is different from B" may also mean "A and B are different from each other." Alternatively, the term may also mean "A and B are each different from C." Terms such as "separate" and "bound" may also be interpreted as meaning "different."

[0305] In this disclosure, when the terms "include," "including," and variations thereof are used, these terms, like the term "comprising," have an inclusive meaning. Furthermore, the term "or" used in this disclosure does not mean an exclusive OR.

[0306] In the present disclosure, when an article is added by translation, for example, as in English, such as a, an, and the, the present disclosure may also include a case where the noun following the article is in a plural form.

[0307] While the inventions disclosed herein have been described in detail above, it will be apparent to those skilled in the art that the inventions disclosed herein are not limited to the embodiments described herein. The inventions disclosed herein can be implemented in modified and altered forms without departing from the spirit and scope of the invention as defined by the claims. Therefore, the descriptions in this disclosure are for illustrative purposes only and are not intended to limit the inventions disclosed herein in any way.

[0308] This application is based on patent application No. 2019-094080 filed on May 17, 2019, all of which are incorporated herein by reference.

Claims

1. A terminal, characterized in that: have: a receiving unit configured to receive downlink control information (DCI) for scheduling specific information to be transmitted by at least one of broadcast and multicast, and the specific information; as well as The control unit determines whether or not to transmit HARQ-ACK, which is retransmission control information for the specific information, based on the information related to retransmission control included in the DCI. The control unit may determine the resource to be used for the HARQ-ACK transmission based on information specifying a specific resource included in the DCI, from among a plurality of resources for the HARQ-ACK transmission notified by higher layer signaling.

2. The terminal according to claim 1, wherein The specific information is the downlink shared channel, namely, PDSCH.

3. A wireless communication method, which is a wireless communication method of a terminal, characterized in that: have: receiving downlink control information (DCI) for scheduling specific information to be transmitted by at least one of broadcast and multicast, and the specific information; a step of determining whether or not to transmit retransmission control information, i.e., HARQ-ACK, for the specific information based on the information related to retransmission control included in the DCI; as well as A step of determining a resource to be used for transmitting the HARQ-ACK based on information specifying a specific resource included in the DCI, from among a plurality of resources for transmitting the HARQ-ACK notified by higher layer signaling.

4. A base station, characterized in that: have: a transmitting unit configured to transmit downlink control information (DCI) for scheduling specific information to be transmitted by at least one of broadcast and multicast, and the specific information; as well as The control unit instructs the terminal whether to transmit HARQ-ACK, which is retransmission control information for the specific information, by using information related to the retransmission control direction included in the DCI. The control unit configures a plurality of resources for transmitting the HARQ-ACK through higher layer signaling, and instructs the terminal on the resources to be used for transmitting the HARQ-ACK through information specifying specific resources included in the DCI.

5. A system having a terminal and a base station, characterized in that: The terminal has: a receiving unit configured to receive downlink control information (DCI) for scheduling specific information to be transmitted by at least one of broadcast and multicast, and the specific information; as well as The control unit determines whether or not to transmit HARQ-ACK, which is retransmission control information for the specific information, based on the information related to retransmission control included in the DCI. The control unit may determine the resource to be used for the HARQ-ACK transmission based on information specifying a specific resource included in the DCI from among a plurality of resources for the HARQ-ACK transmission notified by higher layer signaling. The base station has: A sending unit, sending the DCI and the specific information; a control unit that instructs the terminal whether to transmit the HARQ-ACK using information related to retransmission control included in the DCI, The control unit configures the plurality of resources through the higher layer signaling, and instructs the terminal on the resources to be used for transmitting the HARQ-ACK using information specifying specific resources included in the DCI.

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