User terminal and wireless communication method

Abstract

In order to suppress an increase in a processing load of a UE even when a HARQ-ACK codebook is semi-statically set, a method of a user terminal disclosed in the present invention comprises: a transmitting unit that transmits a delivery confirmation signal for downlink transmission; and a control unit that, when a mode is set in which a codebook for determining the delivery confirmation signal is determined based on information notified through higher layer signaling, controls the transmission of the delivery confirmation signal based on the number of bits of the delivery confirmation signal, or the number of bits of the delivery confirmation signal and the type of cell performing the downlink transmission, by using one of a first PUCCH resource set set for the delivery confirmation signal to be transmitted based on the codebook and a second PUCCH resource set set for the delivery confirmation signal with a number of bits less than a specific value.

Description

Technical Field

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

[0002] In the UMTS (Universal Mobile Telecommunications System) network, Long Term Evolution (LTE) has been standardized for the purpose of further high-speed data rates, low latency, etc. (Non-Patent Document 1). In addition, for the purpose of further broadband and high-speed development of LTE, subsequent systems of LTE (e.g., also known as LTE-A (LTE-Advanced), FRA (Future Radio Access), 4G, 5G, 5G+ (plus), NR (New Radio Access Technology (New RAT)), LTE Rel. 14, 15~, etc.) have also been studied.

[0003] In the existing LTE system (e.g., LTE Rel.8-13), a 1ms subframe (also called a transmission time interval (TTI) or the like) is used for downlink (DL) and / or uplink (UL) communications. The subframe is a transmission time unit for one data packet that is channel-coded, and serves as a processing unit for scheduling, link adaptation, retransmission control (Hybrid Automatic Repeat reQuest (HARQ)), etc.

[0004] In addition, in the existing LTE system (e.g., LTE Rel.8-13), the user terminal uses an uplink control channel (e.g., a physical uplink control channel (PUCCH: Physical Uplink Control Channel)) or an uplink data channel (e.g., a physical uplink shared channel (PUSCH: Physical Uplink Shared Channel)) to send uplink control information (uplink control information (UCI: Uplink Control Information)). The structure (format) of the uplink control channel is called a PUCCH format (PF: PUCCH Format) or the like.

[0005] Prior art literature

[0006] Non-patent literature

[0007] 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

[0008] Problems to be solved by the invention

[0009] In future wireless communication systems (hereinafter, also referred to as NR), a study is being conducted on controlling the feedback of a delivery confirmation signal by semi-statically or dynamically determining the size of a delivery confirmation signal (also referred to as HARQ-ACK, ACK / NACK, or A / N) by a user terminal. The size of HARQ-ACK is also referred to as a codebook, codebook size, or bit string size.

[0010] In the case where a mode of semi-statically determining the HARQ-ACK codebook is set, the UE fixedly determines the HARQ-ACK bits to be fed back based on information notified through high-layer signaling. For example, the UE transmits with a codebook equivalent to the HARQ-ACK for all DL transmissions (e.g., PDSCH) that may be scheduled in a specific range. At this time, the UE feeds back NACK for the PDSCH that is not scheduled in a specific range.

[0011] In this way, when the HARQ-ACK codebook is determined regardless of the number of scheduled DL transmissions, even when the number of actually scheduled DL transmissions is small (for example, 1 or 2), a large number of HARQ-ACK bits need to be sent. As a result, regardless of the number of scheduled DL transmissions, the UE needs to generate a large number of HARQ-ACKs, so there is a concern that the processing load of the UE increases, and the throughput decreases and / or the communication quality deteriorates.

[0012] Therefore, one of the objects of the present disclosure is to provide a user terminal and a wireless communication method that can suppress an increase in the processing load of the UE even when the HARQ-ACK codebook is semi-statically configured.

[0013] Means for solving problems

[0014] A mode of a user terminal of the present invention is characterized in that it comprises: a sending unit that sends a delivery confirmation signal for downlink transmission; and a control unit that, when a mode of determining a codebook for the delivery confirmation signal based on information notified through high-layer signaling is set, controls the transmission of the delivery confirmation signal based on the number of bits of the delivery confirmation signal, or the number of bits of the delivery confirmation signal and the type of cell performing the downlink transmission, using one of a first PUCCH resource set set for the delivery confirmation signal sent based on the codebook and a second PUCCH resource set set for the delivery confirmation signal with a bit number below a specific value.

[0015] Effects of the Invention

[0016] According to one aspect of the present disclosure, even when the HARQ-ACK codebook is semi-statically configured, it is possible to suppress an increase in the processing load of the UE. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a diagram showing an example of feedback control of HARQ-ACK.

[0018] Figure 2 This is a diagram showing an example of HARQ-ACK feedback control in a mode in which the HARQ-ACK codebook is semi-statically determined.

[0019] Figure 3 This is a diagram showing another example of HARQ-ACK feedback control in a mode in which the HARQ-ACK codebook is determined semi-statically.

[0020] Figure 4 This is a diagram showing another example of HARQ-ACK feedback control in a mode in which the HARQ-ACK codebook is determined semi-statically.

[0021] Figure 5 This is a diagram showing another example of HARQ-ACK feedback control in a mode in which the HARQ-ACK codebook is determined semi-statically.

[0022] Figure 6 This is a diagram showing an example of a schematic configuration of a wireless communication system according to the present embodiment.

[0023] Figure 7 It is a diagram showing an example of the overall configuration of a wireless base station according to the present embodiment.

[0024] Figure 8 This is a diagram showing an example of a functional configuration of a wireless base station according to the present embodiment.

[0025] Fig. 9This is a diagram showing an example of the overall configuration of a user terminal according to this embodiment.

[0026] Fig.10 This is a diagram showing an example of a functional configuration of a user terminal according to the present embodiment.

[0027] Fig.11 This is a diagram showing an example of the hardware configuration of a wireless base station and a user terminal according to this embodiment. DETAILED DESCRIPTION

[0028] In NR, a method is being studied for a user terminal to semi-statically or dynamically determine the HARQ-ACK size (HARQ-ACK codebook) and perform HARQ-ACK transmission using PUCCH. For example, a base station notifies a UE of a method for determining the HARQ-ACK codebook through higher layer signaling.

[0029] When the mode of semi-statically determining the HARQ-ACK codebook is set, the UE determines the number of HARQ-ACK bits based on the structure set by the higher-layer signaling. The structure (higher-layer configuration) set by the higher-layer signaling may be, for example, the maximum number of DL transmissions (e.g., PDSCH) scheduled over the range associated with the feedback timing of the HARQ-ACK.

[0030] The range associated with the feedback timing of HARQ-ACK corresponds to at least one (e.g., all) of space, time, and frequency. In addition, the range associated with the feedback timing of HARQ-ACK is also referred to as a HARQ-ACK bundling window, a HARQ-ACK feedback window, a bundling window, or a feedback window.

[0031] On the other hand, when a mode for dynamically determining the HARQ-ACK codebook is set, the UE determines the number of HARQ-ACK bits, etc. based on the bits specified by the DL assignment index (Downlink Assignment Indicator (DAI) (Index)) field included in the downlink control information (e.g., DL assignment).

[0032] In addition, in NR, as an uplink control channel structure (PUCCH format) for sending HARQ-ACK, a PUCCH format for sending UCI with a specific number of bits or less and a PUCCH format for sending UCI with a specific number of bits or more are supported. The PUCCH format for sending UCI with a specific number of bits or less (for example, up to 2 bits) may also be referred to as PUCCH format 0 or PUCCH format 1. The PUCCH format for sending UCI with a specific number of bits or less (for example, more than 2 bits) may also be referred to as PUCCH format 3-5.

[0033] Figure 1 This is a diagram showing an example of feedback control of HARQ-ACK using PUCCH. In this example, the part with "DL" or "UL" attached represents a specific resource (e.g., time / frequency resource), and the period of each part corresponds to an arbitrary time unit (e.g., 1 or more time slots, mini-time slots, symbols, or subframes, etc.). The same applies to the following examples.

[0034] exist Figure 1 In this case, the UE uses the resources of a specific uplink control channel (PUCCH resources) to send the A / N corresponding to the PDSCH (here are 4 DL resources) scheduled in a specific range (bundling window) associated with the feedback of the HARQ-ACK. It can also be set as follows: the feedback timing of the HARQ-ACK for each PDSCH is specified to the UE by scheduling the downlink control information (DL allocation) of each PDSCH.

[0035] When the mode of semi-statically determining the HARQ-ACK codebook is set, the UE performs HARQ-ACK feedback with the number of HARQ-ACK bits that takes into account all PDSCHs that may be scheduled in a specific range (bundling window). That is, the UE controls HARQ-ACK feedback based on the codebook size pre-calculated according to the high-level parameters, regardless of the number of scheduled PDSCHs or the number of DCIs that schedule PDSCHs.

[0036] Specifically, the UE generates HARQ-ACK bits for all PDSCHs assuming that all PDSCHs included in the bundling window are scheduled. This allows the HARQ-ACK codebook to be semi-statically configured regardless of the number of scheduled PDSCHs or the number of DCIs that schedule the PDSCHs.

[0037] Figure 2 An example of semi-statically determining the codebook of HARQ-ACK multiplexed to PUCCH is shown in FIG. Figure 2In FIG. 1 , it is shown that two CCs (or cells) are set for the UE, and the bundling window corresponding to the PUCCH transmission is composed of four time units (for example, four time slots). The bundling window can also be composed based on the HARQ-ACK timing indicated by the downlink control information. In addition, the number of CCs and the duration of the bundling window are not limited to this. In addition, Figure 2 , the case where the spatial direction is set to 1 in each CC (for example, the transport block is set to 1) is shown, but it is not limited to this.

[0038] exist Figure 2 In the first time slot, PDSCH is scheduled in CC#1 and CC#2. In addition, in the second time slot, PDSCH is scheduled in CC#1, in the third time slot, PDSCH is not scheduled, and in the fourth time slot, PDSCH is scheduled in CC#2. That is, it is equivalent to the situation where 4 DL data are actually scheduled within the range of the bundling window (here, the total number is 8 = 2CC×4 time slots).

[0039] The base station notifies the UE of the total number of DL data included in the bundling window (here 8) as a high-level parameter. The UE and the number of scheduled PDSCHs (in Figure 2 The codebook size is determined according to high-level parameters, regardless of the number of DCIs that schedule PDSCHs (4 in the bundling window). The UE feeds back NACK for PDSCHs that are not scheduled in the bundling window.

[0040] In this way, when the HARQ-ACK codebook is determined regardless of the number of scheduled DL transmissions, even when the number of actually scheduled DL transmissions is small (e.g., 1 or 2), a large number of HARQ-ACK bits must always be sent. As a result, there is a concern that the processing load of the UE increases, and the throughput decreases and / or the communication quality deteriorates.

[0041] Therefore, the inventors of the present invention focused on supporting a specific PUCCH format (e.g., PUCCH format 0 / 1) for transmitting HARQ-ACK with a specific number of bits or less, and came up with the idea of ​​using a specific PUCCH format to control HARQ-ACK transmission when the number of HARQ-ACK bits is below a specific value even when the HARQ-ACK codebook is semi-statically set.

[0042] That is, even when the HARQ-ACK codebook is semi-statically configured, if the number of HARQ-ACK bits is less than a specific value, the UE does not send HARQ-ACK with the number of HARQ-ACK bits determined by the higher layer parameters, but with the number of bits less than the specific value. In this way, sending HARQ-ACK in a specific PUCCH format with a number of bits less than a specific value is also called fallback PUCCH transmission.

[0043] The application of fallback PUCCH transmission can also be determined based on the number of bits of the fed-back HARQ-ACK (or the number of PDSCH transmissions that form the basis of the HARQ-ACK). Alternatively, in addition to the number of bits of the HARQ-ACK, it can also be determined based on the type of cell that transmits the DL data that forms the basis of the HARQ-ACK and / or the transmission conditions (for example, the search space type of the DCI that schedules the PDSCH, etc.).

[0044] In addition, when the HARQ-ACK codebook is semi-statically set (for example, the number of bits is larger than a specific value), a PUCCH resource set for HARQ-ACK transmission of the size of the codebook is set. The PUCCH resource set includes multiple PUCCH resources (also called PUCCH resource candidates), and a specific PUCCH resource selected from the multiple PUCCH resources is used to transmit the PUCCH.

[0045] The multiple PUCCH resources included in the PUCCH resource set may also be set to the UE through higher layer signaling. In addition, the selection of a specific PUCCH resource may also be performed using a specific field included in the DCI (or a specific field DCI+RRC and other parameters).

[0046] Therefore, the present inventors have conceived of setting a PUCCH resource set for HARQ-ACK transmission of a size less than a specific value separately from a PUCCH resource set for HARQ-ACK transmission of a codebook size set semi-statically when fallback PUCCH is supported.

[0047] In addition, it is conceivable to use at least one of UE-specific high-layer signaling (UE-specific RRC signalling) and UE-common high-layer signaling (UE-common RRC signalling) to set a PUCCH resource set (or, PUCCH resources) for HARQ-ACK transmission below a specific value.

[0048] The following describes the embodiments of the present disclosure in detail. The following modes can be applied individually or in combination. The following embodiments can be applied individually or in combination.

[0049] In the following embodiments, HARQ-ACK can be replaced by UCI, or by other types of UCI such as Scheduling Request (SR), Channel State Information (CSI), etc. In addition, "2 bits" can also be replaced by "a specific number of bits". In addition, in this specification, "data", "data channel (such as PUSCH)", "data channel resources", etc. can be replaced with each other.

[0050] (First method)

[0051] In the first embodiment, HARQ-ACK transmission in the case of supporting fallback PUCCH transmission in a structure in which the HARQ-ACK codebook is semi-statically set is described. In the following description, a case in which a mode in which the HARQ-ACK codebook is semi-statically determined is described for the UE, but the applicable mode is not limited to this.

[0052] When the base station sets a mode for semi-statically determining the HARQ-ACK codebook for the UE, the base station also sets a PUCCH resource set (first PUCCH resource set) corresponding to the HARQ-ACK codebook. In addition, when the HARQ-ACK codebook set for the UE is a HARQ-ACK bit number greater than a specific value (e.g., 2), the base station sets a PUCCH resource set (second PUCCH resource set) for HARQ-ACK transmission below the specific value separately from the first PUCCH resource set.

[0053] When the number of HARQ-ACK bits in the bundling window (or the number of PDSCHs received or the number of PDCCHs received that require HARQ-ACK transmission) is greater than a specific value, the UE uses the first PUCCH resource set to send the HARQ-ACK generated based on the HARQ-ACK codebook (refer to Figure 2 ). In addition, the bundling window can be the number of PDCCHs or PDSCHs included in the interval of space, time, and frequency derived from semi-static parameters such as RRC signaling, or the number of PDCCHs or PDSCHs included in the interval of space, time, and frequency derived from dynamic signaling such as DCI in addition to semi-static parameters such as RRC signaling.

[0054] On the other hand, when the number of HARQ-ACK bits in the bundling window (or the number of PDSCHs received or the number of PDCCHs received that require HARQ-ACK transmission) is less than a specific value, the UE performs fallback PUCCH transmission. For example, the UE uses a specific PUCCH format and uses the second PUCCH resource set to send HARQ-ACK with a specific number of bits (for example, 2 bits) or less (see Figure 3 ).

[0055] exist Figure 3 In the example, 2 CCs (or cells) are set for the UE, and the bundling window corresponding to the PUCCH transmission is composed of 4 time units (for example, 4 time slots). In addition, the number of CCs and the duration of the bundling window are not limited to this. In addition, in the following description, the case where the spatial direction is set to 1 in each CC (for example, the transport block is set to 1) is indicated, but it is not limited to this.

[0056] exist Figure 3 In the 2nd time slot, PDSCH is scheduled in CC#1, but not in the 1st, 3rd, and 4th time slots. That is, it is equivalent to the case where one DL data (PDSCH) is actually scheduled within the range of the bundling window (here, the total number is 8 = 2CC×4 time slots).

[0057] When HARQ-ACK feedback is performed for one PDSCH in the bundling window, the UE uses a specific PUCCH format and a second PUCCH resource set to control the transmission of HARQ-ACK. As the specific PUCCH format, a PUCCH format for transmission with a specific number of bits or less (for example, PUCCH format 0 / 1) can be used.

[0058] In this way, by applying fallback PUCCH transmission when the feedback HARQ-ACK is less than a specific number of bits, it is not necessary to generate all HARQ-ACKs corresponding to the bundling window, thereby reducing the processing load of the UE.

[0059] In addition, the UE selects a specific PUCCH resource from multiple PUCCH resource candidates included in the second PUCCH resource set to control the transmission of HARQ-ACK. The selection of a specific PUCCH resource can also be based on a specific field included in the DCI (or a specific field included in the DCI + other parameters such as RRC).

[0060] The second PUCCH resource set may also be configured for the UE using at least one of UE-specific higher layer signaling (UE-specific RRC signalling) and UE-common higher layer signaling (UE-common RRC signalling).

[0061] For example, when the second PUCCH resource set is set by UE-specific high-level signaling, the UE applies the second PUCCH resource set set by the UE-specific high-level signaling. That is, even when the second PUCCH resource set is set by UE-common high-level signaling, the second PUCCH resource set set by UE-specific high-level signaling can be preferentially applied.

[0062] At this time, when the second PUCCH resource set is not configured through UE-specific higher layer signaling, the UE may apply the second PUCCH resource set configured through UE-common higher layer signaling.

[0063] The UE common high-layer signaling may be, for example, a high-layer signaling for notifying system information. At this time, the UE determines the second PUCCH resource set based on the system information notified through the high-layer signaling. The system information notified through the high-layer signaling may be the minimum system information (remaining minimum system information (RMSI: Remaining Minimum System Information)), or SIB1 and / or SIB2, or other system information (OSI: Other System Information).

[0064] The system information includes information related to the PUCCH resource set using PUCCH format 0 / 1. The PUCCH resource set included in the system information may also be a PUCCH resource set used for HARQ-ACK (HARQ-ACK before RRC connection setup) for message 4 (Msg.4) in the random access process. That is, as the second PUCCH resource set, the UE may also apply the PUCCH resource set used for HARQ-ACK before RRC connection setup.

[0065] In addition, in the case where the second PUCCH resource set is set by UE-specific high-level signaling and in the case where the second PUCCH resource set is set by UE-common high-level signaling, the method of selecting the PUCCH resource actually sent from the PUCCH resource set may also be different. That is, in the case where the second PUCCH resource set is set by UE-specific high-level signaling and in the case where the second PUCCH resource set is set by UE-common high-level signaling, when the second PUCCH resource set is applied, the UE can select the PUCCH resource to be sent based on different rules.

[0066] In terms of different rules, for example, with respect to selecting PUCCH resources based on a specific field included in the DCI in the case of one party, it can be set to select PUCCH resources without using the field included in the DCI in the case of the other party. In terms of different rules, or, with respect to selecting based on the index of the resource element (CCE) of the PDCCH that schedules the PDSCH corresponding to the HARQ-ACK sent by the PUCCH in the case of one party, it can also be set to select PUCCH resources without using the index of the CCE in the case of the other party.

[0067] In this way, by allowing the PUCCH resource set set by the UE common high-level signaling to be used as the second PUCCH resource set, HARQ-ACK transmission with a specific number of bits or less can be performed even when the PUCCH resource set is not set by the UE-specific high-level signaling. As a result, since fallback PUCCH transmission can be appropriately performed, the increase in the processing load of the UE can be suppressed.

[0068] (Second method)

[0069] In the second embodiment, a case where the application of fallback PUCCH transmission is controlled based on at least one of the number of HARQ-ACK bits (or the number of PDSCHs received or the number of PDCCHs received that require HARQ-ACK transmission), the type of CC (or cell) that transmits PDSCH, and the transmission conditions of PDSCH / DCI is described. The transmission conditions of PDSCH and / or DCI refer to, for example, the type of search space used for the transmission of DCI that schedules PDSCH, etc. In the following, an application example of fallback PUCCH transmission is described.

[0070] <Application Example 1>

[0071] Application Example 1 is an application that controls whether or not to fall back on PUCCH transmission based on the number of PDSCHs (the number of HARQ-ACK bits) in the bundling window.

[0072] For example, when only one PDSCH is transmitted in one serving cell (or when one HARQ-ACK for the PDSCH is fed back), the UE applies fallback PUCCH transmission (refer to Figure 3 ). At this time, the UE selects a specific PUCCH resource from the second PUCCH resource set configured for HARQ-ACK transmission with a specific number of bits (for example, less than 2 bits) and sends HARQ-ACK.

[0073] The UE may also determine a specific PUCCH resource from the second PUCCH resource set based on information included in the DCI for scheduling the PDSCH. For example, the UE may also determine a specific PUCCH resource based on at least one of an ARI field (ARI field) included in the DCI and a HARQ-ACK timing indicator field (HARQ-ACK timing indicator field). The ARI field may also be a TPC command field.

[0074] In addition, in addition to the information contained in the DCI (e.g., a specific field), the UE may also use other parameters (e.g., implicitly notified information) to determine a specific PUCCH resource. As other parameters, there are CCE indexes corresponding to the DCI for scheduling PDSCH, control resource set indexes for sending DCI, etc.

[0075] exist Figure 3 In the example, the case where the number of PDSCHs (the number of HARQ-ACK bits) in the bundling window is 1 and the fallback PUCCH transmission is applied is shown, but it is not limited to this. For example, it is also possible to set the structure where the fallback PUCCH transmission is applied when the number of PDSCHs (the number of HARQ-ACK bits) in the bundling window is 2 or less.

[0076] For example, when 1 or 2 PDSCHs are sent in 1 or 2 serving cells (or, when 1 or 2 HARQ-ACKs are fed back for the PDSCHs), the UE may apply fallback PUCCH transmission (see Figure 4 , 5 ).

[0077] exist Figure 4 In FIG. 1 , it is shown that in the bundling window, two PDSCHs (PDSCHs transmitted in different time slots) are transmitted in one serving cell (here CC#1). Figure 5 , it shows the situation where PDSCH is transmitted one by one in two serving cells (here CC#1 and CC#2) in the bundling window.

[0078] exist Figure 4 , 5 In the bundling window, the UE feeds back HARQ-ACK for two PDSCHs, so fallback PUCCH transmission is applied. The UE selects a specific PUCCH resource from the second PUCCH resource set and sends HARQ-ACK for the two PDSCHs.

[0079] The UE determines a specific PUCCH resource from the second PUCCH resource set based on the information contained in the DCI that schedules the PDSCH. In addition, when DCIs that schedule two PDSCHs are sent separately, the UE may also use the information contained in the DCI of one party (for example, the DCI sent by the CC with a smaller index and / or the DCI sent earlier in the time direction). Alternatively, it may be configured to include information specifying the same PUCCH resource in each DCI.

[0080] In this way, by controlling whether to apply fallback PUCCH transmission based on the number of PDSCHs (the number of HARQ-ACK bits) in the bundling window, it is possible to apply fallback PUCCH transmission regardless of the type of CC that transmits PDSCH.

[0081] <Application Example 2>

[0082] Application Example 2 is an application that controls whether or not to fall back on PUCCH transmission based on the CC (or cell) type in addition to the number of PDSCHs (the number of HARQ-ACK bits) in the bundling window.

[0083] For example, when only one PDSCH is transmitted in one specific cell (or when HARQ-ACK for the PDSCH is fed back), the UE applies fallback PUCCH transmission (refer to Figure 3 ). 1 specific cell ( Figure 3 CC#1 in the example may also be a primary cell (or PSCell, PUCCH SCell). By limiting the application of fallback PUCCH transmission to PDSCH transmission of the primary cell, fallback control can be made more robust. This is because the primary cell is an important cell in connection guarantee among the cells to which the UE is connected.

[0084] The method of selecting a specific PUCCH resource from the second PUCCH resource set may be performed in the same manner as in the above-mentioned application example 1.

[0085] exist Figure 3, the case where fallback PUCCH transmission is applied when the number of PDSCHs transmitted in a specific cell in the bundling window (or the number of HARQ-ACK bits for the PDSCH) is 1 is shown, but the present invention is not limited to this. For example, a structure where fallback PUCCH transmission is applied when the number of PDSCHs transmitted in a specific cell is 2 or less may also be set (refer to Figure 4 ).

[0086] exist Figure 4 In FIG. 1 , it is shown that in the bundling window, two PDSCHs are sent in one specific cell (here CC#1). At this time, the UE only feeds back the HARQ-ACK for the two PDSCHs sent in the specific cell, so the fallback PUCCH transmission is applied. The UE uses the specific PUCCH resources selected from the second PUCCH resource set to send the HARQ-ACK for the two PDSCHs.

[0087] In this way, by controlling the application of whether to fall back on PUCCH transmission in consideration of the type of CC (or cell) that transmits PDSCH, it is possible to control fallback on PUCCH transmission according to the type of CC that transmits PDSCH.

[0088] <Application Example 3>

[0089] Application Example 3 controls whether to fall back on PUCCH transmission based on the transmission conditions of PDSCH and / or DCI in addition to the number of PDSCHs (the number of HARQ-ACK bits) and CC (or cell) type in the bundling window.

[0090] For example, when a PDSCH scheduled by using a DCI (or PDCCH) of a specific search space type is transmitted only in one specific cell, the UE applies fallback PUCCH transmission. Figure 3 The CC#1 in the cell may be, for example, a primary cell (or a PSCell or a PUCCH SCell). The specific search space may also be a common search space (CSS).

[0091] By limiting the application of fallback PUCCH transmission to HARQ-ACK transmitted by PDSCH scheduled by PDCCH (DCI) allocated in the common search space, fallback control can be performed more appropriately. The wireless base station can schedule PDSCH using the common search space only when it wants to fallback PUCCH of the UE.

[0092] The method of selecting a specific PUCCH resource from the second PUCCH resource set may be performed in the same manner as in the above-mentioned application example 1.

[0093] exist Figure 3 , a case where fallback PUCCH transmission is applied when one PDSCH scheduled by using a DCI (or PDCCH) of a specific search space type is transmitted in only one specific cell, but the present invention is not limited thereto. For example, a structure where fallback PUCCH transmission is applied when the number of PDSCHs scheduled by using a DCI (or PDCCH) of a specific search space type is less than 2 may be used (see Figure 4 ).

[0094] exist Figure 4 In FIG. 1 , it is shown that in a bundling window, in a specific cell (here CC#1), two PDSCHs scheduled in a PDCCH sent in a common search space are sent. At this time, since the UE only feeds back HARQ-ACK for the two PDSCHs sent in a specific cell, fallback PUCCH transmission is applied. The UE uses a specific PUCCH resource selected from the second PUCCH resource set to send HARQ-ACK for the two PDSCHs.

[0095] In this way, by controlling whether to fall back to PUCCH transmission in consideration of the search space type of PDCCH (or DCI) transmission for scheduling PDSCH, fallback control can be performed more appropriately. The wireless base station can schedule PDSCH using the common search space only when it wants to fall back to PUCCH for the UE.

[0096] In Application Example 3, a case where fallback PUCCH transmission is controlled in consideration of a specific search space type is shown, but the present invention is not limited thereto. Fallback PUCCH transmission may be controlled based on the type of control resource set (CORESET) or the like instead of the search space type.

[0097] (Wireless Communication System)

[0098] Hereinafter, a configuration of a wireless communication system according to an embodiment of the present invention will be described. In this wireless communication system, communication is performed using any one of the wireless communication methods according to the above-mentioned embodiments of the present invention or a combination thereof.

[0099] Figure 6 The present invention is a diagram showing an example of a schematic structure of a wireless communication system according to an embodiment of the present invention. In the wireless communication system 1, carrier aggregation (CA) and / or dual connectivity (DC) that integrates a plurality of basic frequency blocks (component carriers) can be applied, wherein the basic frequency block is based on the system bandwidth (e.g., 20 MHz) of the LTE system as one unit.

[0100] In addition, the wireless communication system 1 may also be referred to as LTE (Long Term Evolution), LTE-A (LTE-Advanced), LTE-B (LTE-Beyond), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), NR (New Radio) FRA (Future Radio Access), New-RAT (Radio Access Technology), etc., and may also be referred to as a system that implements them.

[0101] The wireless communication system 1 includes a wireless base station 11 that forms a macro cell C1 with a wide coverage, and wireless base stations 12 (12a-12c) that are arranged in the macro cell C1 and form small cells C2 that are narrower than the macro cell C1. In addition, user terminals 20 are arranged in the macro cell C1 and each small cell C2. The arrangement and number of each cell and user terminal 20 are not limited to those shown in the figure.

[0102] The user terminal 20 can connect to both the radio base station 11 and the radio base station 12. It is assumed that the user terminal 20 uses both the macro cell C1 and the small cell C2 by CA or DC. In addition, the user terminal 20 can apply CA or DC using multiple cells (CCs) (e.g., 5 or less CCs, 6 or more CCs).

[0103] The user terminal 20 and the wireless base station 11 can communicate with each other using a carrier with a narrow bandwidth (referred to as an existing carrier, a legacy carrier, etc.) at a relatively low frequency band (e.g., 2 GHz). On the other hand, the user terminal 20 and the wireless base station 12 can use a carrier with a wide bandwidth at a relatively high frequency band (e.g., 3.5 GHz, 5 GHz, etc.), or can use the same carrier as that used between the user terminal 20 and the wireless base station 11. In addition, the structure of the frequency band used by each wireless base station is not limited to this.

[0104] The connection between the wireless base station 11 and the wireless base station 12 (or between two wireless base stations 12) may be a wired connection (for example, optical fiber conforming to CPRI (Common Public Radio Interface), X2 interface, etc.) or a wireless connection.

[0105] The wireless base station 11 and each wireless base station 12 are respectively connected to the upper station device 30, and are connected to the core network 40 via the upper station device 30. In addition, the upper station device 30 includes, for example, an access gateway device, a radio network controller (RNC), a mobility management entity (MME), etc., but is not limited thereto. In addition, each wireless base station 12 can be connected to the upper station device 30 via the wireless base station 11.

[0106] In addition, the wireless base station 11 is a wireless base station with a relatively wide coverage range, and may also be referred to as a macro base station, a convergence node, an eNB (eNodeB), a transmission and reception point, etc. In addition, the wireless base station 12 is a wireless base station with a local coverage range, and may also be referred to as a small base station, a micro base station, a pico base station, a femto base station, a HeNB (Home eNodeB), an RRH (Remote Radio Head), a transmission and reception point, etc. Hereinafter, the wireless base stations 11 and 12 are collectively referred to as wireless base stations 10 without distinguishing between them.

[0107] Each user terminal 20 is a terminal supporting various communication methods such as LTE and LTE-A, and may include not only a mobile communication terminal (mobile station) but also a fixed communication terminal (fixed station).

[0108] In the wireless communication system 1 , as a radio access scheme, Orthogonal Frequency Division Multiple Access (OFDMA) is applied in downlink, and Single Carrier Frequency Division Multiple Access (SC-FDMA) and / or OFDMA is applied in uplink.

[0109] OFDMA is a multi-carrier transmission method that divides the frequency band into multiple narrow frequency bands (subcarriers) and maps data to each subcarrier for communication. SC-FDMA is a single-carrier transmission method that divides the system bandwidth into bands with one or continuous resource blocks for each terminal, and uses different bands by multiple terminals to reduce interference between terminals. In addition, the uplink and downlink wireless access methods are not limited to these combinations, and other wireless access methods can also be used.

[0110] In the wireless communication system 1, a downlink shared channel (physical downlink shared channel (PDSCH: Physical Downlink Shared Channel)), a broadcast channel (physical broadcast channel (PBCH: Physical Broadcast Channel)), a downlink L1 / L2 control channel, etc. shared by each user terminal 20 are used as downlink channels. User data, high-layer control information, SIB (System Information Block), etc. are transmitted through PDSCH. In addition, MIB (Master Information Block) is transmitted through PBCH.

[0111] Downlink L1 / L2 control channels include PDCCH (Physical Downlink Control Channel), EPDCCH (Enhanced Physical Downlink Control Channel), PCFICH (Physical Control Format Indicator Channel), PHICH (Physical Hybrid-ARQ Indicator Channel), etc. Downlink control information (downlink control information (DCI: Downlink Control Information)) including scheduling information of PDSCH and / or PUSCH is transmitted through PDCCH.

[0112] In addition, scheduling information may also be notified through DCI. For example, DCI that schedules DL data reception may also be called DL allocation, and DCI that schedules UL data transmission may also be called UL grant.

[0113] The number of OFDM symbols used for PDCCH is transmitted via PCFICH. The delivery confirmation information (e.g., also called retransmission control information, HARQ-ACK, ACK / NACK, etc.) for HARQ (Hybrid Automatic Repeat reQuest) of PUSCH is transmitted via PHICH. EPDCCH is frequency-division multiplexed with PDSCH (downlink shared data channel) and is used to transmit DCI, etc., in the same way as PDCCH.

[0114] In the wireless communication system 1, as uplink channels, an uplink shared channel (physical uplink shared channel (PUSCH: Physical Uplink Shared Channel)), an uplink control channel (physical uplink control channel (PUCCH: Physical Uplink Control Channel)), a random access channel (physical random access channel (PRACH: Physical Random Access Channel)), etc., which are shared by each user terminal 20, are used. User data, high-layer control information, etc. are transmitted through the PUSCH. In addition, downlink wireless quality information (channel quality indicator (CQI: Channel Quality Indicator)), delivery confirmation information, scheduling request (SR: Scheduling Request), etc. are transmitted through the PUCCH. The random access preamble code used to establish a connection with a cell is transmitted through the PRACH.

[0115] In the wireless communication system 1, as downlink reference signals, a cell-specific reference signal (CRS: Cell-specific Reference Signal), a channel state information reference signal (CSI-RS: Channel State Information-Reference Signal), a demodulation reference signal (DMRS: DeModulation Reference Signal), a positioning reference signal (PRS: Positioning Reference Signal), etc. are transmitted. In addition, in the wireless communication system 1, as uplink reference signals, a measurement reference signal (sounding reference signal (SRS: Sounding Reference Signal)), a demodulation reference signal (DMRS), etc. are transmitted. In addition, DMRS can also be called a user terminal specific reference signal (UE-specific Reference Signal (UE-specific Reference Signal)). In addition, the reference signal transmitted is not limited to this.

[0116] <Wireless base station>

[0117] Figure 7 1 is a diagram showing an example of the overall structure of a wireless base station according to an embodiment of the present invention. The wireless base station 10 includes: a plurality of transmitting and receiving antennas 101, an amplifier unit 102, a transmitting and receiving unit 103, a baseband signal processing unit 104, a call processing unit 105, and a transmission path interface 106. In addition, the structure may include more than one transmitting and receiving antenna 101, amplifier unit 102, and transmitting and receiving unit 103, respectively.

[0118] User data transmitted from the radio base station 10 to the user terminal 20 via the downlink is input from the upper station apparatus 30 to the baseband signal processing unit 104 via the transmission path interface 106 .

[0119] In the baseband signal processing unit 104, for user data, transmission processing such as PDCP (Packet Data Convergence Protocol) layer processing, user data segmentation / combination, RLC (Radio Link Control) retransmission control and other RLC layer transmission processing, MAC (Medium Access Control) retransmission control (for example, HARQ transmission processing), scheduling, transmission format selection, channel coding, inverse fast Fourier transform (IFFT) processing, precoding processing and the like are performed, and the transmission is forwarded to the transmission and reception unit 103. In addition, for downlink control signals, transmission processing such as channel coding and inverse fast Fourier transform are also performed, and the signals are forwarded to the transmission and reception unit 103.

[0120] The transmitting and receiving unit 103 converts the baseband signal outputted from the baseband signal processing unit 104 according to each antenna precoding into a radio frequency band and transmits it. The radio frequency signal subjected to frequency conversion in the transmitting and receiving unit 103 is amplified by the amplifier unit 102 and transmitted from the transmitting and receiving antenna 101. The transmitting and receiving unit 103 can be composed of a transmitter / receiver, a transmitting and receiving circuit, or a transmitting and receiving device explained based on the common knowledge in the technical field involved in the present invention. In addition, the transmitting and receiving unit 103 can be configured as an integrated transmitting and receiving unit, or can be configured by a transmitting unit and a receiving unit.

[0121] On the other hand, regarding the uplink signal, the radio frequency signal received by the transmitting / receiving antenna 101 is amplified by the amplifier unit 102. The transmitting / receiving unit 103 receives the uplink signal amplified by the amplifier unit 102. The transmitting / receiving unit 103 frequency-converts the received signal into a baseband signal and outputs it to the baseband signal processing unit 104.

[0122] In the baseband signal processing unit 104, the user data included in the input uplink signal is subjected to fast Fourier transform (FFT) processing, inverse discrete Fourier transform (IDFT) processing, error correction decoding, MAC retransmission control reception processing, RLC layer and PDCP layer reception processing, and is forwarded to the upper station device 30 via the transmission path interface 106. The call processing unit 105 performs call processing (setting, release, etc.) of the communication channel, state management of the wireless base station 10, management of wireless resources, etc.

[0123] The transmission path interface 106 sends and receives signals via a specific interface with the upper station device 30. In addition, the transmission path interface 106 can send and receive (backhaul signaling) signals with other wireless base stations 10 via an inter-base station interface (e.g., an optical fiber or an X2 interface in accordance with CPRI (Common Public Radio Interface)).

[0124] In addition, the transmitting and receiving unit 103 notifies the UE of which mode is used for the semi-statically determined mode and the dynamically determined mode of the codebook for HARQ-ACK through high-layer signaling, etc. In addition, the transmitting and receiving unit 103 receives the HARQ-ACK (HARQ-ACK based on the codebook and HARQ-ACK sent with fallback PUCCH applied) sent from the UE.

[0125] In addition, the transmitting and receiving unit 103 notifies the UE of information about the PUCCH resource set corresponding to the HARQ-ACK transmitted based on the HARQ-ACK codebook and the PUCCH resource set for HARQ-ACK transmission with a specific number of bits or less through high-layer signaling, etc. In addition, the transmitting and receiving unit 103 may also send information specifying a specific PUCCH resource from a plurality of PUCCH resource candidates included in the PUCCH resource set through downlink control information, etc.

[0126] Figure 8 This is a diagram showing an example of a functional configuration of a wireless base station according to an embodiment of the present invention. In this example, the functional blocks of the characteristic parts of this embodiment are mainly shown, and it is assumed that the wireless base station 10 also has other functional blocks required for wireless communication.

[0127] The baseband signal processing unit 104 includes at least a control unit (scheduler) 301, a transmission signal generating unit 302, a mapping unit 303, a reception signal processing unit 304, and a measuring unit 305. In addition, these configurations only need to be included in the wireless base station 10, and some or all of the configurations may not be included in the baseband signal processing unit 104.

[0128] The control unit (scheduler) 301 controls the entire wireless base station 10. The control unit 301 can be configured by a controller, a control circuit, or a control device described based on common knowledge in the technical field to which the present invention relates.

[0129] The control unit 301 controls, for example, signal generation by the transmission signal generation unit 302 and signal allocation by the mapping unit 303. The control unit 301 also controls signal reception processing by the reception signal processing unit 304 and signal measurement by the measurement unit 305.

[0130] The control unit 301 controls the scheduling (e.g., resource allocation) of system information, downlink data signals (e.g., signals sent in PDSCH), and downlink control signals (e.g., signals sent in PDCCH and / or EPDCCH. Delivery confirmation information, etc.). In addition, the control unit 301 controls the generation of downlink control signals, downlink data signals, etc. based on the result of the determination of whether retransmission control of uplink data signals is required, etc. In addition, the control unit 301 performs scheduling control of synchronization signals (e.g., PSS (Primary Synchronization Signal) / SSS (Secondary Synchronization Signal)), downlink reference signals (e.g., CRS, CSI-RS, DMRS), etc.

[0131] In addition, the control unit 301 controls the setting of a first PUCCH resource set corresponding to the HARQ-ACK transmitted based on the HARQ-ACK codebook and a second PUCCH resource set for HARQ-ACK transmission with a specific number of bits or less. For example, the control unit 301 controls so that at least one of the PUCCH resource set configured in a UE-specific manner through high-layer signaling and the PUCCH resource set configured in a UE-common manner through high-layer signaling is configured as the second PUCCH resource set.

[0132] The transmission signal generating unit 302 generates a downlink signal (downlink control signal, downlink data signal, downlink reference signal, etc.) based on the instruction from the control unit 301, and outputs it to the mapping unit 303. The transmission signal generating unit 302 can be composed of a signal generator, a signal generating circuit, or a signal generating device explained based on the common knowledge in the technical field involved in the present invention.

[0133] The transmission signal generating unit 302 generates, for example, a DL allocation for notifying allocation information of downlink data and / or a UL grant for notifying allocation information of uplink data based on an instruction from the control unit 301. Both the DL allocation and the UL grant are DCI and follow the DCI format. In addition, the downlink data signal is coded and modulated according to a coding rate and a modulation method determined based on channel state information (CSI: Channel State Information) from each user terminal 20.

[0134] Based on the instruction from the control unit 301, the mapping unit 303 maps the downlink signal generated in the transmission signal generation unit 302 to a specific wireless resource and outputs it to the transmission and reception unit 103. The mapping unit 303 can be composed of a mapper, a mapping circuit or a mapping device described based on the common knowledge in the technical field involved in the present invention.

[0135] The received signal processing unit 304 performs reception processing (e.g., demapping, demodulation, decoding, etc.) on the received signal input from the transmitting and receiving unit 103. Here, the received signal is, for example, an uplink signal (uplink control signal, uplink data signal, uplink reference signal, etc.) transmitted from the user terminal 20. The received signal processing unit 304 can be composed of a signal processor, a signal processing circuit, or a signal processing device described based on the common knowledge in the technical field involved in the present invention.

[0136] The reception signal processing unit 304 outputs the information decoded by the reception processing to the control unit 301. For example, when a PUCCH including HARQ-ACK is received, the HARQ-ACK is output to the control unit 301. In addition, the reception signal processing unit 304 outputs the reception signal and / or the signal after reception processing to the measurement unit 305.

[0137] The measurement unit 305 performs measurement on the received signal. The measurement unit 305 can be composed of a measurement device, a measurement circuit, or a measurement apparatus described based on the common knowledge in the technical field to which the present invention relates.

[0138] For example, the measuring unit 305 may perform RRM (Radio Resource Management) measurement, CSI (Channel State Information) measurement, etc. based on the received signal. The measuring unit 305 may also measure received power (e.g., RSRP (Reference Signal Received Power)), received quality (e.g., RSRQ (Reference Signal Received Quality)), SINR (Signal to Interference plus Noise Ratio)), signal strength (e.g., RSSI (Received Signal Strength Indicator)), propagation path information (e.g., CSI), etc. The measurement result may be output to the control unit 301.

[0139] <User terminal>

[0140] Fig. 9 1 is a diagram showing an example of the overall structure of a user terminal according to an embodiment of the present invention. The user terminal 20 includes a plurality of transmit / receive antennas 201, an amplifier unit 202, a transmit / receive unit 203, a baseband signal processing unit 204, and an application unit 205. In addition, the configuration may include at least one transmit / receive antenna 201, an amplifier unit 202, and a transmit / receive unit 203.

[0141] The radio frequency signal received by the transmitting and receiving antenna 201 is amplified in the amplifier unit 202. The transmitting and receiving unit 203 receives the downlink signal amplified in the amplifier unit 202. The transmitting and receiving unit 203 converts the received signal frequency into a baseband signal and outputs it to the baseband signal processing unit 204. The transmitting and receiving unit 203 can be composed of a transmitter / receiver, a transmitting and receiving circuit, or a transmitting and receiving device described based on the common understanding in the technical field involved in the present invention. In addition, the transmitting and receiving unit 203 can be composed of a transmitting and receiving unit as an integrated transmitting and receiving unit, or can be composed of a transmitting unit and a receiving unit.

[0142] The baseband signal processing unit 204 performs FFT processing, error correction decoding, reception processing of retransmission control, etc. on the input baseband signal. The downlink user data is forwarded to the application unit 205. The application unit 205 performs processing related to layers higher than the physical layer and the MAC layer, etc. In addition, broadcast information can also be forwarded to the application unit 205 in the downlink data.

[0143] On the other hand, uplink user data is input from the application unit 205 to the baseband signal processing unit 204. In the baseband signal processing unit 204, transmission processing of retransmission control (for example, transmission processing of HARQ), channel coding, precoding, discrete Fourier transform (DFT: Discrete Fourier Transform) processing, IFFT processing, etc. are performed and forwarded to the transmission and reception unit 203. The transmission and reception unit 203 converts the baseband signal output from the baseband signal processing unit 204 into a radio frequency band and transmits it. The radio frequency signal subjected to frequency conversion in the transmission and reception unit 203 is amplified by the amplifier unit 202 and transmitted from the transmission and reception antenna 201.

[0144] In addition, the transmitting and receiving unit 203 receives which of the modes semi-statically determined and dynamically determined using the codebook for HARQ-ACK in the UE through high-layer signaling, etc. In addition, the transmitting and receiving unit 203 transmits the HARQ-ACK sent from the UE (the HARQ-ACK based on the codebook and the HARQ-ACK to which the fallback PUCCH transmission is applied).

[0145] In addition, the transmitting and receiving unit 203 receives information about a PUCCH resource set corresponding to a HARQ-ACK transmitted based on the HARQ-ACK codebook and a PUCCH resource set for transmitting HARQ-ACK with a specific number of bits or less. In addition, the transmitting and receiving unit 203 may also receive information specifying a specific PUCCH resource from a plurality of PUCCH resource candidates included in the PUCCH resource set.

[0146] Fig.10 1 is a diagram showing an example of a functional configuration of a user terminal according to an embodiment of the present invention. In this example, the functional blocks of the characteristic parts of this embodiment are mainly shown, and it is assumed that the user terminal 20 also has other functional blocks required for wireless communication.

[0147] The baseband signal processing unit 204 included in the user terminal 20 includes at least a control unit 401, a transmission signal generating unit 402, a mapping unit 403, a reception signal processing unit 404, and a measurement unit 405. In addition, these structures may be included in the user terminal 20, and some or all of the structures may not be included in the baseband signal processing unit 204.

[0148] The control unit 401 controls the entire user terminal 20. The control unit 401 can be configured by a controller, a control circuit, or a control device that is commonly known in the technical field to which the present invention relates.

[0149] The control unit 401 controls, for example, signal generation by the transmission signal generation unit 402 , signal allocation by the mapping unit 403 , etc. The control unit 401 also controls signal reception processing by the reception signal processing unit 404 , signal measurement by the measurement unit 405 , and the like.

[0150] The control unit 401 obtains the downlink control signal and the downlink data signal transmitted from the wireless base station 10 from the reception signal processing unit 404. The control unit 401 controls the generation of the uplink control signal and / or the uplink data signal based on the downlink control signal and / or the result of determining whether retransmission control of the downlink data signal is required.

[0151] In addition, when a mode is set in which a codebook for determining a delivery confirmation signal based on information notified through high-layer signaling is determined, the control unit 401 controls the transmission of the delivery confirmation signal based on the number of bits of the delivery confirmation signal, or the number of bits of the delivery confirmation signal and the type of cell performing the downlink transmission, using a first PUCCH resource set set for the delivery confirmation signal to be sent based on the codebook and a second PUCCH resource set set for the delivery confirmation signal with a number of bits less than a specific value.

[0152] For example, the control unit 401 controls the transmission of the delivery confirmation signal using at least one of a PUCCH resource set configured in a UE-specific manner through high-layer signaling and a PUCCH resource set configured in a UE-common manner through high-layer signaling as a second PUCCH resource set. The control unit 401 controls so that, when a PUCCH resource set configured in a UE-specific manner is not configured, a PUCCH resource set configured in a UE-common manner is used. The control unit 401 may also determine a PUCCH resource set configured in a UE-common manner based on system information.

[0153] In addition, the control unit 401 may also perform control so that when a downlink signal is transmitted in the primary cell or a downlink signal is scheduled in a downlink control channel of a common search space, a delivery confirmation signal for downlink transmission is transmitted using the second PUCCH resource set.

[0154] The transmission signal generating unit 402 generates an uplink signal (uplink control signal, uplink data signal, uplink reference signal, etc.) based on the instruction from the control unit 401, and outputs it to the mapping unit 403. The transmission signal generating unit 402 can be composed of a signal generator, a signal generating circuit, or a signal generating device explained based on the common knowledge in the technical field involved in the present invention.

[0155] The transmission signal generating unit 402 generates an uplink control signal related to the delivery confirmation information, channel state information (CSI), etc., based on, for example, an instruction from the control unit 401. In addition, the transmission signal generating unit 402 generates an uplink data signal based on an instruction from the control unit 401. For example, when the downlink control signal notified from the radio base station 10 includes a UL grant, the transmission signal generating unit 402 is instructed by the control unit 401 to generate an uplink data signal.

[0156] Based on the instruction from the control unit 401, the mapping unit 403 maps the uplink signal generated in the transmission signal generation unit 402 to the wireless resource and outputs it to the transmission and reception unit 203. The mapping unit 403 can be composed of a mapper, a mapping circuit or a mapping device explained based on the common knowledge in the technical field involved in the present invention.

[0157] The received signal processing unit 404 performs reception processing (e.g., demapping, demodulation, decoding, etc.) on the received signal input from the transmitting and receiving unit 203. Here, the received signal is, for example, a downlink signal (downlink control signal, downlink data signal, downlink reference signal, etc.) transmitted from the wireless base station 10. The received signal processing unit 404 can be composed of a signal processor, a signal processing circuit, or a signal processing device explained based on the common knowledge in the technical field involved in the present invention. In addition, the received signal processing unit 404 can constitute the receiving unit involved in the present invention.

[0158] The received signal processing unit 404 outputs the information decoded by the reception processing to the control unit 401. The received signal processing unit 404 outputs, for example, broadcast information, system information, RRC signaling, DCI, etc. to the control unit 401. In addition, the received signal processing unit 404 outputs the received signal and / or the received processed signal to the measuring unit 405.

[0159] The measurement unit 405 performs measurement on the received signal. The measurement unit 405 can be composed of a measurement device, a measurement circuit, or a measurement apparatus described based on the common knowledge in the technical field to which the present invention relates.

[0160] For example, the measurement unit 405 may perform RRM measurement, CSI measurement, etc. based on the received signal. The measurement unit 405 may measure received power (e.g., RSRP), received quality (e.g., RSRQ, SINR), signal strength (e.g., RSSI), propagation path information (e.g., CSI), etc. The measurement result may be output to the control unit 401.

[0161] <Hardware Structure>

[0162] In addition, the block diagram used in the description of the above-mentioned embodiment represents the block of the functional unit. These functional blocks (structural units) are implemented by any combination of hardware and / or software. In addition, the implementation method of each functional block is not particularly limited. That is, each functional block can be implemented by using one device that is physically and / or logically combined, or two or more devices that are physically and / or logically separated can be directly and / or indirectly (for example, using wired and / or wireless) connected and implemented using these multiple devices.

[0163] For example, a wireless base station, a user terminal, etc. in one embodiment of the present invention can function as a computer that performs processing of the wireless communication method of the present invention. Fig.11 1 is a diagram showing an example of a hardware structure of a wireless base station and a user terminal according to an embodiment of the present invention. The wireless base station 10 and the user terminal 20 can 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, and a bus 1007.

[0164] In the following description, the word "device" can be replaced by circuit, equipment, unit, etc. The hardware configuration of the radio base station 10 and the user terminal 20 may include one or more of the devices shown in the figure, or may exclude some of the devices.

[0165] For example, only one processor 1001 is shown, but there may be multiple processors. In addition, the processing may be performed by one processor, or the processing may be performed by more than one processor simultaneously, sequentially, or using other methods. In addition, the processor 1001 may also be implemented by more than one chip.

[0166] The various functions in the wireless base station 10 and the user terminal 20 are implemented, for example, as follows: specific software (program) is read into hardware such as the processor 1001 and the memory 1002, and the processor 1001 performs calculations and controls communication via the communication device 1004, or controls the reading and / or writing of data in the memory 1002 and the storage 1003.

[0167] The processor 1001 controls the entire computer by, for example, operating an operating system. The processor 1001 may be composed of a central processing unit (CPU) including an interface with peripheral devices, a control device, a computing device, registers, etc. For example, the baseband signal processing unit 104 (204), the call processing unit 105, etc., may also be implemented by the processor 1001.

[0168] In addition, the processor 1001 reads the program (program code), software module, data, etc. from the storage 1003 and / or the communication device 1004 to the memory 1002, and performs various processes based on them. As a program, a program that causes a computer to perform at least a part of the operations described in the above embodiments is used. For example, the control unit 401 of the user terminal 20 can be implemented by a control program stored in the memory 1002 and operated in the processor 1001, and other functional blocks can also be implemented in the same way.

[0169] The memory 1002 is a computer-readable recording medium, and may be composed of at least one of a ROM (Read Only Memory), an EPROM (Erasable Programmable ROM), an EEPROM (Electrically EPROM), a RAM (Random Access Memory), or other suitable storage media. 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 an executable program (program code), a software module, etc. for implementing the wireless communication method of one embodiment of the present invention.

[0170] The storage 1003 is a computer-readable recording medium, and may be composed of at least one of a flexible disk, a floopy (registered trademark) disk, an optical disk (e.g., an optical disk (CD-ROM (Compact Disc ROM)), a digital versatile disk, a Blu-ray (registered trademark) disk), a removable disk, a hard disk drive, a smart card, a flash memory device (e.g., a card, a stick, 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.

[0171] The communication device 1004 is hardware (transmitting and receiving device) for communicating between computers via a wired and / or wireless network, and is also called a network device, a network controller, a network card, a communication module, etc. The communication device 1004 may also be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc., for example, in order to realize frequency division duplex (FDD: Frequency Division Duplex) and / or time division duplex (TDD: Time Division Duplex). For example, the above-mentioned transmitting and receiving antenna 101 (201), amplifier unit 102 (202), transmitting and receiving unit 103 (203), and transmission path interface 106, etc., may also be realized by the communication device 1004.

[0172] The input device 1005 is an input device that receives input from the outside (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.). The output device 1006 is an output device that performs output to the outside (e.g., a display, a speaker, an LED (Light Emitting Diode) lamp, etc.). In addition, the input device 1005 and the output device 1006 may also be an integrated structure (e.g., a touch panel).

[0173] In addition, the processor 1001, the memory 1002 and other devices are connected via a bus 1007 for information communication. The bus 1007 may be configured by a single bus or by different buses between devices.

[0174] In addition, the wireless base station 10 and the user terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), and an FPGA (Field Programmable Gate Array), and may also use the hardware to implement a part or all of each functional block. For example, the processor 1001 may be implemented using at least one of these hardware.

[0175] (Variation Example)

[0176] In addition, the terms described in this specification and / or the terms required for understanding of this specification can be replaced with terms having the same or similar meanings. For example, a channel and / or a code element can also be a signal (signaling). In addition, a signal can also be a message. A reference signal can also be referred to as RS (Reference Signal), and depending on the applied standard, it can also be referred to as a pilot (Pilot), a pilot signal, etc. In addition, a component carrier (CC) can also be referred to as a cell, a frequency carrier, a carrier frequency, etc.

[0177] In addition, a wireless frame may also be composed of one or more periods (frames) in the time domain. The one or more periods (frames) constituting a wireless frame may also be referred to as a subframe. Further, a subframe may also be composed of one or more time slots in the time domain. A subframe may be a fixed duration (e.g., 1 ms) that is not dependent on a parameter set (Numerology).

[0178] Furthermore, a time slot may also be composed of one or more symbols (OFDM (Orthogonal Frequency Division Multiplexing)) symbols, SC-FDMA (Single Carrier Frequency Division Multiple Access)) symbols, etc.) in the time domain. In addition, a time slot may be a time unit based on a parameter set (Numerology). In addition, a time slot may include multiple mini-slots. Each mini-slot may be composed of one or more symbols in the time domain. In addition, a mini-slot may also be called a sub-slot.

[0179] Radio frames, subframes, time slots, mini-time slots, and symbols all represent time units for transmitting signals. Radio frames, subframes, time slots, mini-time slots, and symbols may also use other names corresponding to each other. For example, one subframe may also be called a transmission time interval (TTI), multiple consecutive subframes may also be called TTI, and one time slot or one mini-time slot may also be called TTI. That is, a subframe and / or TTI may be a subframe (1ms) in an existing LTE, or a period shorter than 1ms (for example, 1-13 symbols), or a period longer than 1ms. In addition, the unit representing TTI may also be called a time slot, a mini-time slot, etc. instead of a subframe.

[0180] Here, TTI refers to, for example, the minimum time unit for scheduling in wireless communication. For example, in the LTE system, a wireless base station schedules each user terminal to allocate wireless resources (frequency bandwidth, transmission power, etc. that can be used in each user terminal) in units of TTI. In addition, the definition of TTI is not limited to this.

[0181] TTI may be a time unit for transmitting a data packet (transport block), a code block and / or a code word after channel coding, and may also be a processing unit for scheduling, link adaptation, etc. In addition, when a TTI is given, the time region (e.g., the number of symbols) to which a transport block, a code block and / or a code word is actually mapped may be shorter than the TTI.

[0182] In addition, when 1 time slot or 1 mini time slot is referred to as TTI, more than 1 TTI (i.e., more than 1 time slot or more than 1 mini time slot) can be the minimum time unit of scheduling. In addition, the number of time slots (number of mini time slots) constituting the minimum time unit of scheduling can be controlled.

[0183] A TTI with a duration of 1 ms may also be referred to as a normal TTI (TTI in LTE Rel.8-12), a normal TTI, a long TTI, a normal subframe, a normal subframe, or a long subframe, etc. A TTI shorter than a normal TTI may also be referred to as a shortened TTI, a short TTI, a partial or fractional TTI, a shortened subframe, a short subframe, a mini slot, or a subslot, etc.

[0184] In addition, long TTI (e.g., normal TTI, subframe, etc.) can also be replaced by a TTI with a duration exceeding 1 ms, and short TTI (e.g., shortened TTI, etc.) can also be replaced by a TTI with a TTI length shorter than that of long TTI and longer than 1 ms.

[0185] Resource block (RB) is a resource allocation unit in the time domain and frequency domain. In the frequency domain, it may also include one or more continuous subcarriers (subcarriers). In addition, RB may include one or more symbols in the time domain, and may also be the length of one time slot, one mini time slot, one subframe or one TTI. One TTI and one subframe may also be composed of one or more resource blocks, respectively. In addition, one or more RBs may also be referred to as physical resource blocks (PRB), subcarrier groups (SCG), resource element groups (REG), PRB pairs, RB pairs, etc.

[0186] In addition, 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.

[0187] In addition, the structures of the above-mentioned radio frames, subframes, time slots, mini-time slots, and symbols are only examples. For example, the number of subframes included in a radio frame, the number of time slots in each subframe or radio frame, the number of mini-time slots included in a time slot, the number of symbols and RBs included in a time slot or mini-time slot, the number of subcarriers included in an RB, the number of symbols in a TTI, the symbol length, and the cyclic prefix (CP: Cyclic Prefix) length can be changed in various ways.

[0188] In addition, the information, parameters, etc. described in this specification can be expressed using absolute values, relative values ​​relative to a specific value, or other corresponding information. For example, wireless resources can also be indicated by a specific index.

[0189] The names used for parameters and the like in this specification are not restrictive names at all. For example, various channels (PUCCH (Physical Uplink Control Channel), PDCCH (Physical Downlink Control Channel), etc.) and information elements can be identified by all appropriate names, and thus the various names assigned to these various channels and information elements are not restrictive names at all.

[0190] Information, signals, etc. described in this specification may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, code elements, and chips mentioned throughout the above description may also be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any combination thereof.

[0191] In addition, information, signals, etc. can be output from a higher layer to a lower layer and / or from a lower layer to a higher layer. Information, signals, etc. can also be input and output via multiple network nodes.

[0192] The input and output information, signals, etc. may be stored in a specific area (e.g., a memory) or managed using a management table. The input and output information, signals, etc. may also be overwritten, updated, or added. The output information, signals, etc. may also be deleted. The input information, signals, etc. may also be sent to other devices.

[0193] The notification of information is not limited to the method / implementation method described in this specification, and other methods may also be used. For example, the notification of information may be implemented through physical layer signaling (e.g., downlink control information (DCI: Downlink Control Information), uplink control information (UCI: Uplink Control Information)), high-layer signaling (e.g., RRC (Radio Resource Control) signaling, broadcast information (Master Information Block (MIB: Master Information Block), System Information Block (SIB: System Information Block), etc.), MAC (Medium Access Control) signaling), other signals or a combination thereof.

[0194] In addition, physical layer signaling may also be referred to as L1 / L2 (Layer 1 / Layer 2) 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, RRC connection setup (RRCConnectionSetup) message, RRC connection reconstruction (RRCConnectionReconfiguration) message, etc. In addition, MAC signaling may be notified using, for example, a MAC control element (MACCE (Control Element)).

[0195] Furthermore, notification of specific information (for example, notification of “it is X”) is not limited to explicit notification, but may be performed implicitly (for example, by not notifying the specific information or by notifying other information).

[0196] The determination may be made by a value represented by one bit (0 or 1), by a true or false value (Boolean) represented by true (true) or false (false), or by comparison of numerical values ​​(for example, comparison with a specific value).

[0197] Software, whether referred to as software, firmware, middleware, microcode, hardware description language, or by other names, shall be construed broadly to mean instructions, instruction sets, codes, code segments, program code, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, execution threads, procedures, functions, etc.

[0198] In addition, software, instructions, information, etc. can be sent and received via transmission media. For example, when software is sent from a website, server, or other remote source using wired technology (coaxial cable, optical cable, twisted pair, and digital subscriber line (DSL, etc.) and / or wireless technology (infrared, microwave, etc.), these wired technology and / or wireless technology are included in the definition of transmission media.

[0199] The terms "system" and "network" used in this specification can be used interchangeably.

[0200] In this specification, the terms "base station (BS)", "radio base station", "eNB", "gNB", "cell", "sector", "cell group", "carrier" and "component carrier" can be used interchangeably. Base stations are also referred to as fixed stations, NodeB, eNodeB (eNB), access points, transmission points, reception points, femtocells, small cells, etc.

[0201] A base station can accommodate one or more (for example, three) cells (also called sectors). When a base station accommodates multiple cells, the overall coverage area of ​​the base station can be divided into multiple smaller areas, and each smaller area can 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 part or all of the coverage area of ​​a base station and / or a base station subsystem that provides communication services within the coverage area.

[0202] In this specification, the terms "mobile station (MS)", "user terminal (user terminal)", "user equipment (UE)" and "terminal" are used interchangeably. Base stations are also referred to as fixed stations (fixed stations), NodeB, eNodeB (eNB), access points (access points), transmission points, reception points, femto cells, small cells, etc.

[0203] A mobile station is also sometimes referred to by those skilled in the art 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 handheld device, a user agent, a mobile client, a client or some other appropriate terminology.

[0204] In addition, the wireless base station in this specification may also be replaced by a user terminal. For example, the various methods / implementations of the present invention may also be applied to a structure in which the communication between a wireless base station and a user terminal is replaced by communication between multiple user terminals (device-to-device (D2D: Device-to-Device)). In this case, the user terminal 20 may be configured to have the functions of the above-mentioned wireless base station 10. In addition, the words "uplink" and "downlink" may also be replaced by "side". For example, the uplink channel may also be replaced by a side channel.

[0205] Likewise, the user terminal in this specification may be replaced by a wireless base station. In this case, the wireless base station 10 may be configured to have the functions of the user terminal 20 described above.

[0206] In this specification, operations are assumed to be performed by a base station, and sometimes, depending on the circumstances, they are also performed by its upper node. In a network including one or more network nodes having a base station, various operations performed for communication with a terminal can obviously be performed by a base station, one or more network nodes other than the base station (for example, consider MME (Mobility Management Entity), S-GW (Serving-Gateway), etc., but not limited to this) or a combination thereof.

[0207] Each method / implementation method described in this specification may be used alone, in combination, or switched during execution. In addition, the processing procedures, timings, flow charts, etc. of each method / implementation method described in this specification may be swapped in order as long as they are not contradictory. For example, with respect to the method described in this specification, the elements of various steps are presented in the order of examples, and are not limited to the specific order presented.

[0208] The various modes and implementation modes described in this specification can be applied to LTE (Long Term Evolution), LTE-A (LTE-Advanced), LTE-B (LTE-Beyond), SUPER3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), FRA (Future Radio Access), New-RAT (Radio Access Technology), NR (New Radio), NX (New radio access), FX (Future generation radio access), GSM (registered trademark) (Global System for Mobile communications), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth (registered trademark), and systems using other appropriate wireless communication methods and / or next-generation systems expanded based on them.

[0209] The phrase “based on” used in this specification does not mean “based only on” unless otherwise clearly described. In other words, the phrase “based on” means both “based only on” and “based at least on”.

[0210] Any reference to an element using the terms "first", "second", etc. used in this specification is not intended to fully define the amount or order of these elements. These terms may be used in this specification as a convenient method of distinguishing between two or more elements. Therefore, a reference to a first and a second element does not mean that only two elements may be used or that the first element must be located before the second element in some form.

[0211] The term "determining" used in this specification sometimes includes a variety of operations. For example, "determining" can be regarded as "determining" calculation, computing, processing, deriving, investigating, looking up (for example, searching in a table, database or other data structure), ascertaining, etc. In addition, "determining" can be regarded as "determining" receiving (for example, receiving information), transmitting (for example, sending information), input, output, accessing (for example, accessing data in a memory), etc. In addition, "determining" can be regarded as "determining" solving, selecting, choosing, establishing, comparing, etc. That is, "determining" can be regarded as "determining" certain operations.

[0212] The terms "connected", "coupled", etc., or all their variations, used in this specification mean all direct or indirect connections or combinations between two or more elements, and can include the situation where there are one or more intermediate elements between the two elements that are "connected" or "coupled" to each other. The combination or connection between elements can be physical, logical, or a combination thereof. For example, "connection" can also be replaced by "access".

[0213] In this specification, when two elements are connected, it can be considered that they are "connected" or "combined" to each other using one or more wires, cables, and / or printed electrical connections, and as some non-limiting and non-exhaustive examples, using electromagnetic energy with wavelengths in the wireless frequency domain, microwave region, and / or light (both visible and invisible) region, etc.

[0214] In the present specification, the term "A is different from B" may also mean "A and B are different from each other." The terms "separate" and "combined" may also be interpreted in the same manner.

[0215] When the terms "including", "comprising" and their variations are used in this specification or claims, these terms are intended to be inclusive, similar to the term "having". Furthermore, the term "or" used in this specification or claims does not mean a logical exclusive OR.

[0216] The present invention has been described in detail above, but it is obvious to those skilled in the art that the present invention is not limited to the embodiments described in this specification. The present invention can be implemented as a modification and variation without departing from the purpose and scope of the present invention determined by the description of the claims. Therefore, the description of this specification is for the purpose of exemplary description and does not bring any restrictive meaning to the present invention.

Claims

1. A terminal, characterized in that: have: a receiving unit, receiving a downlink shared channel scheduled by downlink control information; and a control unit, controlling the sending of a delivery confirmation signal received on the downlink shared channel, In a case where a semi-statically determined codebook is set for a terminal, the control unit determines whether to use a first codebook or a second codebook as the codebook for sending the delivery confirmation signal, wherein the first codebook is determined when the number of downlink shared channel receptions in a time interval associated with feedback timing of the delivery confirmation signal is greater than 1, and the second codebook is determined when the number of downlink shared channel receptions in the time interval is 1 and the downlink shared channel is scheduled in a primary cell.

2. The terminal according to claim 1, characterized in that The first codebook is determined when the number of downlink shared channel receptions in the time interval is 1 and the downlink shared channel is scheduled in a cell different from the primary cell.

3. A wireless communication method for a terminal, characterized in that: have: The step of receiving a downlink shared channel scheduled by downlink control information; and controlling the transmission of a delivery confirmation signal received on the downlink shared channel, The method further comprises: when a semi-statically determined codebook is set in a terminal, determining whether to use a first codebook or a second codebook as the codebook used for transmitting the delivery confirmation signal; The first codebook is determined when the number of downlink shared channel receptions in a time interval associated with feedback timing of the delivery confirmation signal is greater than 1, and the second codebook is determined when the number of downlink shared channel receptions in the time interval is 1 and the downlink shared channel is scheduled in a primary cell.

4. A base station, characterized in that: have: A sending unit, sending a downlink shared channel scheduled by downlink control information to a terminal; a receiving unit, receiving, from the terminal, a delivery confirmation signal sent for the downlink shared channel; as well as A control unit that, when a semi-statically determined codebook is set for the terminal, controls the terminal to receive the delivery confirmation signal transmitted using a first codebook when the number of downlink shared channel transmissions in a time interval associated with feedback timing of the delivery confirmation signal is greater than 1, and controls the terminal to receive the delivery confirmation signal transmitted using a second codebook when the number of downlink shared channel transmissions in the time interval is 1 and the downlink shared channel is scheduled in a primary cell.

5. A system having a terminal and a base station, characterized in that: The terminal has: a receiving unit, receiving a downlink shared channel scheduled by downlink control information; and a control unit, controlling the sending of a delivery confirmation signal received on the downlink shared channel, In a case where a semi-statically determined codebook is set for a terminal, the control unit determines whether to use a first codebook or a second codebook as the codebook for sending the delivery confirmation signal, wherein the first codebook is determined when the number of downlink shared channel receptions in a time interval associated with feedback timing of the delivery confirmation signal is greater than 1, and the second codebook is determined when the number of downlink shared channel receptions in the time interval is 1 and the downlink shared channel is scheduled in a primary cell, The base station has: A sending unit, sending the downlink shared channel to the terminal; a receiving unit, receiving the delivery confirmation signal from the terminal; and A control unit that, when the codebook is set for the terminal, controls the terminal to receive the delivery confirmation signal sent using the first codebook when the number of downlink shared channel transmissions in the time interval is greater than 1, and controls the terminal to receive the delivery confirmation signal sent using the second codebook when the number of downlink shared channel transmissions in the time interval is 1 and the downlink shared channel is scheduled in the primary cell.

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