BR112019018060B1 - RADIOCOMMUNICATION TERMINAL AND METHOD - Google Patents

Abstract

The present invention is designed so that DL data can be received, and HARQ-ACK can be transmitted, properly even when data scheduling methods different from existing LTE systems are used. According to one aspect of the present invention, a user terminal has a receiving section that receives DL control information, and a control section that controls the reception of DL data scheduled by the DL control information, and the transmission of delivery confirmation information in response to the DL data, and the DL control information indicates a relationship between the reception timing of the DL control information, the reception timing of the DL data, and the transmission timing of the delivery confirmation information, and the control section determines, based on the DL control information, the reception timing of the DL data and the transmission timing of the delivery confirmation information.

Description

Technical Field

[001] The present invention relates to a user terminal and a radio communication method in next generation mobile communication systems.

Previous Technique

[002] In the UMTS (Universal Mobile Telecommunications System) network, Long Term Evolution (LTE) specifications were developed for the purpose of further increasing high-speed data rates, providing lower latency, and so on (see non-patent literature 1). In addition, LTE-A (also referred to as “LTE-Advanced”, “LTE Rel. 10”, “LTE Rel. 11”, or “LTE Rel. 12”) specifications have been developed for additional broadbandization and higher speeds beyond LTE (also known as “LTE Rel. 8” or “LTE Rel. 9”) and successor systems to LTE (also known as, for example, “FRA (Future Radio Access)”, “5G (5th Generation Mobile System)”, “5G+ (plus)”, “NR (New Radio)”, “NX (New Radio Access)”, “FX (Future Generation Radio Access)”, “LTE Rel. 13”, “LTE Rel. 14”, “LTE Rel. 15”, or later versions) are under study.

[003] In existing LTE systems (e.g., LTE Rel. 8 through 13), downlink (DL) and/or uplink (UL) communication is performed using 1 ms subframes (also called “transmission time intervals (TTIs)”), and so on). These subframes are the unit of time to transmit a channel-encoded data packet and serve as the processing unit in, for example, scheduling, link adaptation, retransmission control (HARQ (Hybrid Automatic Repeat Request)), and so on.

[004] A radio base station controls the allocation (scheduling) of data to a user terminal and reports the data scheduling to the user terminal (e.g., UE (User Equipment)) using downlink control information (DCI). The user terminal controls DL data reception and uplink data transmission based on the downlink control information. For example, in the existing LTE system, when the user terminal receives the downlink control information to command UL transmission (e.g., UL grant), the user terminal transmits uplink data in a subframe after a predetermined period (e.g., after 4 ms).

List of Quotes Non-Patented Literature

[005] Non-Patent Literature 1: 3GPP TS36.300 V8.12.0 “Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); General Description; Stage 2 (Release 8)”, April 2010

Summary of the Invention Technical Problem

[006] Future radio communication systems (e.g., LTE Rel. 14, 15 or later versions, 5G, NR, etc.) are assumed to control data scaling based on different configurations than existing LTE systems (e.g., LTE Rel. 13 or earlier versions).

[007] For example, in existing LTE systems, DL data in each subframe is scheduled based on downlink control information that is transmitted per predetermined transmission time slot (subframe). Furthermore, based on the downlink control information transmitted in a given subframe, UL data is scheduled for a predetermined period thereafter. In contrast to this, future radio communication systems are under research to utilize the downlink control information that is transmitted in a given transmission time slot (e.g., a slot) to control data scheduling (UL data and/or DL data) in this same slot and/or in different slots. Note that controlling data scheduling in different slots based on downlink control information in a predetermined slot is also known as “cross-slot scheduling.”

[008] When cross-slot scheduling is used, the problem is how to control the DL data timing and the HARQ-ACK timing in response to the DL data. The problem in controlling the DL data timing and the HARQ-ACK timing is how to allow the user terminal to determine the DL data timing and the HARQ-ACK timing.

[009] The present invention was made in view of the above, and it is therefore an object of the present invention to provide a user terminal and a radio communication method by which data can be transmitted and/or received properly even when data scheduling methods that are different from those of existing LTE systems are applied.

Solution to the Problem

[010] According to one aspect of the present invention, a user terminal has a receiving section that receives the DL control information and a control section that controls the receipt of DL data scheduled by the DL control information, and the transmission of delivery acknowledgement information in response to the DL data and the DL control information indicates a relationship between the timing of receiving the DL control information, the timing of receiving the DL data, and the timing of transmitting the delivery acknowledgement information, and the control section determines, based on the DL control information, a timing of receiving the DL data and a timing of transmitting the delivery acknowledgement information.

Advantageous Effects of the Invention

[011] According to the present invention, data can be transmitted and/or received properly even when data scaling methods different from those of existing LTE systems are applied.Brief Description of the Drawings

[012] FIG. 1 is a diagram for showing an example of cross-scheduling between slots; FIGS. 2A and 2B are diagrams for showing examples of scheduling according to the first embodiment of the present invention; FIGS. 3A to 3C are diagrams for showing examples of an association between k and m and indication information; FIG. 4 is a diagram for showing an example of cross-scheduling between slots; FIGS. 5A and 5B are diagrams for showing examples of the HARQ-ACK transmission method 1; FIGS. 6A and 6B are diagrams for showing examples of the HARQ-ACK transmission method 2; FIG. 7 is a diagram for showing an example of an association between k, m, and w and indication information; FIG. 8 is a diagram for showing an exemplary schematic structure of a radio communication system according to an embodiment of the present invention; FIG. 9 is a diagram for showing an exemplary general structure of a radio base station according to an embodiment of the present invention; FIG. 10 is a diagram for showing an exemplary functional structure of a radio base station according to an embodiment of the present invention; FIG. 11 is a diagram for showing an exemplary general structure of a user terminal according to an embodiment of the present invention; FIG. 12 is a diagram for showing an exemplary functional structure of a user terminal according to an embodiment of the present invention; and FIG. 13 is a diagram for showing an exemplary hardware structure of a radio base station and a user terminal according to an embodiment of the present invention.

Description of Modalities

[013] In existing LTE systems, a base station transmits downlink control information (DCI) to a UE using a downlink control channel (e.g., PDCCH (Physical Downlink Control Channel), Enhanced PDCCH (EPDCCH (Enhanced PDCCH), etc.). Transmitting downlink control information can be interpreted as transmitting a downlink control channel.

[014] The DCI may be scheduling information, including at least one of, for example, data scheduling time/frequency resources, transport block information, data modulation scheme information, HARQ retransmission information, demodulation RS information, and so on. The DCI that schedule the receipt of DL data and/or the measurements of DL reference signals may be referred to as “DL assignment” or “DL grant,” and the DCI that schedule the transmission of UL data and/or the transmission of UL probing (measurement) signals may be referred to as “UL grant.” DL assignments and/or UL grants may include information related to channel capabilities, sequences, and transmission formats for transmitting UL control signals (UCI (Uplink Control Information)), such as HARQ-ACK feedback in response to DL data, channel measurement information (CSI (Channel State Information)), and so on. Additionally, DCIs for scheduling UL control signals (UCI (Uplink Control Information)) may be defined in addition to the DL assignment and UL grants.

[015] Furthermore, for future radio communication systems, a study is underway to utilize downlink control information, transmitted in a given transmission time interval (e.g., a slot), to control scheduling of UL data and/or DL data in the same slot and/or in different slots (see FIG. 1).

[016] FIG. 2 shows a case where downlink control information (downlink control channel) transmitted in a predetermined slot (#n, in this case) controls scheduling in the predetermined slot (#n) and in another slot (#n+1). The UE controls the transmission and/or reception of data in a predetermined slot (#n) and another slot (#n+1) based on the downlink control information received in the predetermined slot (#n). Scheduling data in a different slot (here, slot #n+1) using the downlink control information of the specific slot (here, slot #n) is also referred to as “cross-slot scheduling”. Note that scheduling data of the same particular slot using the downlink control information in a specific slot is also known as “self-slot scheduling”.

[017] When cross-slot scheduling is employed, cases occur where, in the slots in which data is scheduled, the downlink control information that schedules this data is not necessarily transmitted. In this case, it is a problem how the UE judges the timing at which the DL data is allocated (also called “schedule timing”).

[018] Incidentally, in future radio communication systems (e.g., NR), UEs will likely have varying processing capabilities. Some UEs may also support signal processing with shorter processing latency.

[019] For example, certain UEs may support autonomous operations. Here, autonomous operation may indicate, for example, an operation of completing the receipt of a specific DL signal (data signal, etc.) and transmitting (feedback) a UL signal based on this DL signal (HARQ-ACK, etc.) within a specific period (subframe, slot, etc.). That is, UEs supporting autonomous operations are assumed to contain high processing capacity.

[020] Therefore, when a UE supporting autonomous operation detects DL grant for DL data in subframe #n, the UE may transmit HARQ-ACK in response to the DL data in the same subframe #n. Furthermore, when the UE detects a UL grant for UL data in subframe #n, the UE may transmit the UL data in subframe #n.

[021] Meanwhile, another UE may need a longer processing time. This processing time may differ between different UEs.

[022] The minimum HARQ processing time at the UE is also known as the “minimum HARQ processing capacity”. The HARQ processing time may include the latency between the timing of receiving DL data and the timing of transmitting the corresponding HARQ-ACK (also called the “HARQ-ACK timing”). For example, if the minimum HARQ processing capacity for a UE is 3 slots, the time for this UE elapsed between the timing of receiving DL data and the timing of transmitting HARQ-ACK cannot be less than 3 slots.

[023] The minimum HARQ processing capability for a UE depends on the processing capability of that UE; the UE may report its own minimum HARQ processing capability to the radio base station.

[024] If the UE's processing capabilities vary, preferably, the HARQ-ACK timing can be configured flexibly. However, the problem is how the UE judges the HARQ-ACK timing.

[025] Furthermore, considering the efficiency of resource utilization, it is preferable that the timing of DL data and HARQ-ACK can be dynamically changed. The present inventors have come up with the idea of reporting the scheduling timing and HARQ-ACK timing to the user terminal using the downlink control information.

[026] Now, an embodiment of the present invention will be described in detail below with reference to the accompanying drawings. Note that the radio communication methods according to each embodiment may be applied individually or may be applied in combination. Although the cases are illustrated with the following embodiment where data scheduling is controlled on a per-slot basis, other time units may be used in the same way (e.g., subframes, minislots, subslots, transmission time intervals (TTIs), short TTIs, radio frames, etc.)

(Radio Communication Method) <First Modality>

[027] The first embodiment of the present invention describes the case where DCI in 1 slot schedules DL data in the same slot or in another slot.

[028] For example, as shown in FIG. 2A or FIG. 2B, the DCIs are transmitted in slot #n, and the DL data scheduled by the DCIs are transmitted in slot #n+k. Here, k is an integer equal to 0 or more. Such scheduling is called “self-slot scheduling” when k is 0 and “cross-slot scheduling” when k is positive.

[029] The DCI dynamically specifies the value of k, which indicates the scheduling timing. In addition, the DCI dynamically specifies the value of m, which indicates the HARQ-ACK timing. As a result, this allows the radio base station to dynamically configure the DL data scheduling timing and the HARQ-ACK timing in response to DL data to the user terminal.

[030] «HARQ-ACK Timing Setting Method»HARQ-ACK timing setting methods 1 and 2 will be described, which are examples of HARQ-ACK timing setting methods.

[031] In the HARQ-ACK timing configuration method 1, as shown in FIG. 2A, m is specified by the DCI, and the HARQ-ACK in response to a slot scheduled by the DCI is transmitted in the #n+m slot. That is, the HARQ-ACK is transmitted in the m-th slot, counting from the slot in which the DCI is received.

[032] Here, the UE assumes that m is k or more (m>=k). That is, the slot for transmitting the HARQ-ACK is equal to or later than the slot in which the corresponding DL data is received.

[033] Furthermore, the value of m-k is equal to or greater than the minimum HARQ processing capability of the UE. That is, the time from the last slot to receive DL data based on 1 DCI to the slot to transmit HARQ-ACK in response to the DCI is equal to the time required for the UE to process the DL data or more.

[034] According to the HARQ-ACK timing configuration method 1, the radio base station determines the HARQ-ACK timing based on the minimum HARQ processing capability of the UE and the time at which the DL data is scheduled (e.g., the value of k), so that it is possible to avoid a situation where the UE's reception process is not in time and fails to receive the next data. Furthermore, it is possible to flexibly configure the DL data scheduling timing and the HARQ-ACK timing.

[035] In the HARQ-ACK timing configuration method 2 as shown in FIG. 2B, m is specified by the DCI and the HARQ-ACK in response to a slot scheduled by the DCI is transmitted in the #n+m+k slot. That is, the HARQ-ACK is transmitted in the m-th slot, counting from the slot in which the DL data is transmitted.

[036] Here, the UE assumes that m is 0 or more (m>=0). That is, the slot for transmitting the HARQ-ACK is equal to or later than the slot in which the corresponding DL data is received.

[037] Furthermore, the value of m is equal to or greater than the minimum HARQ processing capability of the UE. That is, the time from the last slot to receive DL data based on 1 DCI to the slot to transmit HARQ-ACK in response to the DCI is equal to the time required for the UE to process the DL data or longer.

[038] According to the HARQ-ACK timing setting method 1, according to the HARQ-ACK timing setting method 2, it is possible to avoid a situation where the UE's receiving process is not in time and does not receive the next data. This allows the amount of information reported in the HARQ-ACK timing setting method 2 to be less than the amount of information reported in the HARQ-ACK timing setting method 1. This allows the amount of information reported in the HARQ-ACK timing setting method 2 to be less than the amount of information reported in the HARQ-ACK timing setting method 1.

[039] «DCI Structure»In the following, DCI structures 1-1 and 1-2, which are examples of DCI structure showing scheduling timing and HARQACK timing, will be described.

[040] In the 1-1 structure of the DCI, the DCI separately includes an indication information (indicator) field A for indicating a scheduling timing, and an indication information field B for indicating HARQ-ACK timing. The value of k may be associated with the value of the indication information A, and the value of m may be associated with the value of the indication information B. For example, a plurality of candidates for the value of k associated with a plurality of candidates for the value of the indication information A, and a plurality of candidates for the value of m associated with a plurality of candidates for the value of the indication information B, may be configured by higher layer signaling (e.g., RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, etc.).

[041] For example, if indication information A and B are a 2-bit field in the DCI, each indication information may assume 4 values. In this case, 4 values of k associated with the 4 values of indication information A as shown in FIG. 3A and 4 values of m associated with the 4 values of indication information B as shown in FIG. 3B may be configured for the UE through higher layer signaling. Subsequently, the UE may determine the scheduling timing and HARQ-ACK timing by receiving DCI and identifying k and m respectively associated with the values of indication information A and B.

[042] According to the 1-1 structure of DCI, the scheduling timing and the HARQ-ACK timing may be configured independently. For example, the HARQ-ACK timing may be configured independently of changes in the scheduling timing.

[043] In the DCI structure 1-2, the DCI includes a field of an indication information C indicating that the scheduling timing and HARQ-ACK timing pair A of values {K, m} may be associated with the indication information value C. For example, multiple candidates of value pairs {k, m} associated with multiple candidates of the indication information C may be configured via higher layer signaling.

[044] For example, when the C indication information is a 3-bit field, the C indication information may assume 8 values. In this case, as shown in FIG. 3C, 8 pairs of values of {k, m}, each associated with 8 values of the C indication information, may be configured via higher layer signaling. Subsequently, the UE may determine the scheduling timing and HARQ-ACK timing by receiving the DCI and acknowledging the values of k and m based on the value of the C indication information.

[045] According to the DCI structure 1-2, k and m can be configured in one field, so that it is possible to reduce the amount of k and m information dynamically reported from the radio base station to the UE.

<Second Modality>

[046] The second embodiment of the present invention describes the case where DCI in 1 slot schedules the DL data into multiple slots. This scheduling is also known as “multi-slot scheduling”, “slot aggregation”.

[047] For example, as shown in FIG. 4, the DCI is transmitted in slot #n and the DL data scaled by the DCI is transmitted in multiple slots from slot #n+k to slot #n+k+w-1. Here, w is an integer of 1 or more.

[048] w indicates the number of slots scheduled by the DCI in slot #n. The base sequence related information may be configured by upper layer signaling (e.g., RRC (Radio Resource Control) or MAC (Medium Access Control) signaling), may be signaled by broadcast information (the MIB (Master Information Block), SIBs (System Information Blocks), etc.), may be indicated by physical layer signaling (e.g., Downlink Control Information (DCI)), or may be configured from the network (e.g., a radio base station) to a UE by combining these signalings.

[049] A plurality of DL data over the w slots may be different transport blocks (TB) with different HARQ processes. In this case, the overhead can be reduced and the data rate can be improved.

[050] A plurality of DL data over w slots may be the same transport blocks with the same HARQ processes. In this case, a plurality of DL data over w slots may be transport blocks with the same redundancy version or transport blocks with different redundancy versions. In this case, as the same data is transmitted repeatedly, the coverage may be expanded.

[051] The DCI dynamically specifies the value of k, which indicates the scheduling timing. In addition, the DCI dynamically specifies the value of m, which indicates the HARQ-ACK timing. As a result, this allows the radio base station to dynamically configure the DL data scheduling timing and the HARQ-ACK timing in response to DL data to the user terminal.

[052] Next, HARQ-ACK transmission methods 1 and 2 will be described, which are examples of a method of transmitting HARQ-ACK in response to DL data in multiple slots.

[053] «HARQ-ACK Transmission Method 1 and HARQ-ACK Timing Configuration Method»In HARQ-ACK transmission method 1, based on the upper layer configuration, a plurality of HARQ-ACKs based on 1 DCI are grouped or multiplexed and transmitted in the same slot. For example, when grouping is used, the UE compresses multiple HARQ-ACKs and transmits the compressed information in 1 field in 1 slot. When multiplexing is used, the UE transmits multiple HARQ-ACKs in multiple fields in 1 slot, respectively.

[054] HARQ-ACK timing setting methods 1-1 and 1-2 are described, which are examples of the HARQ-ACK timing setting method for HARQ-ACK transmission method 1.

[055] In the 1-1 HARQ-ACK timing configuration method as shown in FIG. 5A, m is specified by the DCI, the HARQ-ACKs in response to several slots #n+k, #n+k+1, ..., #n+k+w-1 staggered by the DCI are transmitted in a slot #n+m. That is, the HARQ-ACK is transmitted in the m-th slot, counting from the slot in which the DCIs are received.

[056] Here, the UE assumes that m is k+w-1 or more (m>=k+w-1). That is, the slot to transmit HARQ-ACK is equal to or later than the last slot to receive the corresponding DL data.

[057] Furthermore, the value of m-k-w+1 is equal to or greater than the minimum HARQ processing capability of the UE. That is, the timing from the last slot to receive DL data based on 1 DCI to the slot to transmit HARQ-ACK in response to the DCI is equal to the timing required for the UE to process the DL data or more.

[058] In the HARQ-ACK timing configuration method 1-2 as shown in FIG. 5B, m is specified by the DCI, HARQ-ACKs in response to a number of slots #n+k, #n+k+1, ..., #n+k+w-1 scheduled by the DCI are transmitted in a slot #n+m+k+w-1. That is, the HARQ-ACK is transmitted in the m-th slot, counting from the last slot in the w slots in which DL data is received.

[059] Here, the UE assumes that m is 0 or more (m>=0). That is, the slot to transmit HARQ-ACK is equal to or later than the last slot to receive the corresponding DL data.

[060] Furthermore, the value of m is equal to or greater than the minimum HARQ processing capacity of the UE. That is, the time from the last slot to receive DL data based on 1 DCI to the slot to transmit HARQ-ACK in response to the DCI is equal to the time required for the UE to process the DL data or more.

[061] According to the HARQ-ACK transmission method 1 described above, HARQ-ACKs in response to DL data of multiple slots are transmitted in 1 slot, so that the amount of resources to allocate to HARQ-ACKs can be reduced.

[062] «HARQ-ACK Transmission Method 2 and HARQ-ACK Timing Configuration Method»In the HARQ-ACK transmission method 2, a plurality of HARQ-ACKs based on 1 DCI are transmitted in a plurality of slots, respectively. That is, a plurality of HARQ-ACKs, respectively, corresponding to a plurality of slots staggered by 1 DCI are transmitted in different slots.

[063] HARQ-ACK timing configuration methods 2-1 and 2-2 are described, which are examples of the HARQ-ACK Timing Configuration Method for HARQ-ACK Transmission Method 2.

[064] In the 2-1 HARQ-ACK timing configuration method as shown in FIG. 6A, m is specified by the DCI, HARQ-ACKs in response to a number of slots #n+k, #n+k+1, ..., #n+k+w-1 staggered by the DCI are transmitted in a number of slots #n+m, #n+m+1, ..., #n+m+w-1, respectively. That is, the HARQ-ACK is transmitted in the m-th slot, counting from the slot in which the DL data is received. Furthermore, the HARQ-ACK in response to the DL data is transmitted in the m-k-th slot, counting from the slot in which the DL data is received.

[065] Here, the UE assumes that m is k+w-1 or more (m>=k+w-1). That is, the slot to transmit HARQ-ACK is equal to or later than the last slot to receive the corresponding DL data.

[066] Furthermore, the value of m-k-w+1 is equal to or greater than the minimum HARQ processing capability of the UE. That is, the time from the last slot to receive DL data based on 1 DCI to the slot to transmit HARQ-ACK in response to the DCI is equal to the time required for the UE to process the DL data or more.

[067] In the 2-2 HARQ-ACK timing configuration method as shown in FIG. 6B, m is specified by the DCI, HARQ-ACKs in response to multiple slots #n+k, #n+k+1, ..., #n+k+w-1 staggered by the DCI are transmitted in multiple slots #n+m+k, #n+m+k+1, ..., #n+m+k+w-1, respectively. That is, the HARQ-ACK is transmitted in the m-th slot, counting from the slot in which the DL data is received.

[068] Here, the UE assumes that m is 0 or more (m>=0). That is, the slot to transmit HARQ-ACK is equal to or later than the last slot to receive the corresponding DL data.

[069] Furthermore, the value of m-k is equal to or greater than the minimum HARQ processing capability of the UE. That is, the time from the last slot to receive DL data based on 1 DCI to the slot to transmit HARQ-ACK in response to the DCI is equal to the time required for the UE to process the DL data or more.

[070] According to the above HARQ-ACK transmission method 1, the HARQ-ACK timing can be more easily controlled by calculating the time of each slot in which DL data scaled by 1 DCI is received in the slot in which the corresponding HARQ-ACK is transmitted constantly.

[071] Note that in FIGS. 5 relating to HARQ-ACK transmission method 1, HARQ-ACKs in response to all DCI-scheduled TBs are transmitted at the same time, in FIGS. 6 relating to HARQ-ACK transmission method 2, HARQ-ACKs in response to DCI-scheduled TBs are transmitted individually, but these examples are not limiting in any way. For example, HARQ-ACKs in response to part of the DCI-scheduled TBs may be grouped or multiplexed and transmitted, and HARQ-ACKs in response to other TBs may be transmitted individually. Which TBs are grouped or multiplexed and which are not may be designated by explicit signaling or may be determined based on implicit rules. For example, when DCIs span multiple TBs, it is possible to batch or multiplex and transmit HARQ-ACKs in response to temporally early TBs (close to the time the DCI was detected) and transmit each HARQ-ACK individually in response to temporally late TBs (far from the time the DCI was detected). In this case, it is easy to reserve the time needed to transmit HARQ-ACK feedback in response to the temporally delayed TB while reducing the HARQ-ACK feedback overhead.

[072] «Structure of INN»In the following, the 2-1, 2-2 and 2-3 structures of INN, which are examples of the INN structure according to the second embodiment, will be described.

[073] Similar to the DCI structure 1-1, in the DCI structure 2-1, the DCIs separately include a field for indication information A to indicate scheduling timing, and a field for indication information B to indicate HARQ-ACK timing. The value of k may be associated with the value of indication information A, and the value of m may be associated with the value of indication information B. For example, a plurality of candidates for the value of k associated with a plurality of candidates for the value of indication information A, and a plurality of candidates for the value of m associated with a plurality of candidates for the value of indication information B may be configured via higher layer signaling. The value of w in this case may be configured via higher layer signaling or reported by broadcast information.

[074] For example, if indication information A and B are a 2-bit field in the DCI, each indication information may assume 4 values. In this case, 4 values of k associated with the 4 values of indication information A, as shown in FIG. 3A, and 4 values of m associated with the 4 values of indication information B, as shown in FIG. 3B, may be configured to the UE through higher layer signaling. Subsequently, the UE may determine the scheduling timing and HARQ-ACK timing by receiving the DCI and identifying k and m respectively associated with the values of indication information A and B.

[075] According to the DCI 2-1 structure, the scheduling timing and the HARQ-ACK timing may be configured independently. For example, the HARQ-ACK timing may be configured independently of changes in the scheduling timing.

[076] Similar to the DCI structure 1-2, in the DCI structure 2-2, the DCI includes a field of an indication information C, indicating the scheduling timing and the HARQ-ACK timing. A pair of values of {k, m} may be associated with the value of the indication information C. For example, multiple candidates of value pairs {k, m} associated with multiple candidates of the indication information C may be configured through higher layer signaling.

[077] The value of w in this case can be configured via upper layer signaling or reported by broadcast information.

[078] For example, when the indication information C is a 3-bit field, the indication information C may assume 8 values. In this case, as shown in FIG. 3C, 8 pairs of values of {k, m}, each associated with 8 values of the indication information C, may be configured through higher layer signaling. Subsequently, the UE may determine the scheduling timing and the HARQ-ACK timing by receiving the DCI and acknowledging the values of k and m based on the value of the indication information C.

[079] According to the 2-2 structure of the DCI, k and m can be configured in one field, so that it is possible to reduce the amount of k and m information dynamically reported from the radio base station to the UE.

[080] In the DCI structure 2-3, the DCI includes an indication information D field that indicates scheduling timing, HARQ-ACK timing, and the number of slots scheduled by the DCI. A {k, m, w} value pair may be associated with the indication information D value. For example, multiple candidate {k, m, w} value pairs associated with multiple candidate indication information D may be configured via higher layer signaling.

[081] For example, when the indication information D is a 3-bit field, the indication information D may assume 8 values. In this case, as shown in FIG. 7, 8 pairs of values of {k, m, w}, each associated with 8 values of the indication information D, may be configured via higher layer signaling. Subsequently, the UE may determine the scheduling timing and the HARQ-ACK timing by receiving the DCI and acknowledging the values of k, m, and w based on the value of the indication information D.

[082] According to the DCI structure 2-3, k, m and w can be configured in one field, so that it is possible to reduce the amount of k, m and w information dynamically reported from the radio base station to the UE.

[083] Note that the DCI may include indication information (field) to indicate pairs of k and m, and indication information (field) to indicate w. Note that the DCI may include indication information (field) to indicate pairs of k and w, and indication information (field) to indicate m. Note that the DCI may include indication information (field) to indicate pairs of m and w, and indication information (field) to indicate k.

[084] Note that the present embodiment shows the case where 1 DCI schedules multiple contiguous slots, but multiple non-contiguous slots may be scheduled. In this case, w may indicate the total number of slots in the period specified by the DCI or the number of scheduled slots (DL data is allocated) in the period specified by the DCI. Further, the information may be configured to show scheduled slots during the period specified by the DCI. This information may be a slot number showing scheduled slots or a bitmap showing whether or not each slot is scheduled. Further, the information may be configured to show un-scheduled slots (DL data is allocated or empty) during the period specified by the DCI.

[085] Thus, the UE may use the above-mentioned HARQACK transmission methods 1 and 2 even if the DCI schedules several non-contiguous slots.

[086] (Radio Communication System) Now, the structure of the radio communication system according to an embodiment of the present invention will be described below. In this radio communication system, communication is performed using one of the radio communication methods according to the embodiments herein of the present invention, or a combination thereof.

[087] FIG. 8 is a diagram for showing an example of a schematic structure of a radio communication system according to an embodiment of the present invention. A radio communication system 1 may adopt carrier aggregation (CA) and/or dual connectivity (DC) to group a plurality of fundamental frequency blocks (component carriers) into one, where the LTE system bandwidth (e.g., 20 MHz) constitutes a unit.

[088] Note that the radio communication system 1 may 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)” and so on, or may be observed as a system for implementing these.

[089] The radio communication system 1 includes a radio base station 11 that forms a macrocell C1 with relatively wide coverage, and radio base stations 12a to 12c that are placed within the macrocell C1 and that form small cells C2 that are narrower than the macrocell C1. Also, user terminals 20 are placed in the macrocell C1 and in each small cell C2. The arrangement, number, and so on, of cells and user terminals are not limited to those illustrated in the drawings.

[090] The user terminals 20 may connect to both the radio base station 11 and the radio base stations 12. The user terminals 20 may utilize the macro cell C1 and the small cells C2 at the same time via AC or DC. Furthermore, the user terminals 20 may apply AC or DC utilizing a plurality of cells (CCs) (e.g., 5 or fewer CCs or 6 or more CCs).

[091] Between the user terminals 20 and the radio base station 11, communication may be performed using a carrier of a relatively low frequency band (e.g., 2 GHz) and a narrow bandwidth (referred to as, e.g., an “existing carrier,” a “legacy carrier,” and so on). Furthermore, between the user terminals 20 and the radio base stations 12, a carrier of a relatively high frequency band (e.g., 3.5 GHz, 5 GHz, and so on) and a wide bandwidth may be used, or the same carrier as that used at the radio base station 11 may be used. Note that the frequency band structure for use at each radio base station is by no means limited to these.

[092] A structure may be utilized herein in which a wired connection (e.g., fiber optic, which is compliant with CPRI (Common Public Radio Interface), the X2 interface, and so on) or wireless connection is established between the radio base station 11 and the radio base station 12 (or between 2 radio base stations 12).

[093] The radio base station 11 and the radio base stations 12 are each connected to the higher station apparatus 30, and are connected to a core network 40 via the higher station apparatus 30. Note that the higher station apparatus 30 may be, for example, an access gateway apparatus, a radio network controller (RNC), a mobility management entity (MME), and so on, but are not limited to these. Also, each radio base station 12 may be connected to the higher station apparatus 30 via the radio base station 11.

[094] Note that radio base station 11 is a radio base station having relatively wide coverage, and may be referred to as a “macro base station,” a “central node,” an “eNB (eNodeB),” a “transmit/receive point,” and so on. Also, radio base stations 12 are radio base stations having local coverage, and may be referred to as “small base stations,” “micro base stations,” “pico base stations,” “femto base stations,” “HeNBs (eNodes Home),” “RRHs (Remote Radio Heads),” “transmit/receive points,” and so on. Hereinafter, radio base stations 11 and 12 will be collectively referred to as “radio base stations 10” unless otherwise specified.

[095] User terminals 20 are terminals for supporting various communication schemes such as LTE, LTE-A, and so on, and may be mobile communication terminals (mobile stations) or stationary communication terminals (fixed stations).

[096] In radio communication system 1, as radio access schemes, orthogonal frequency division multiple access (OFDMA) is applied to the downlink and single carrier frequency division multiple access (SC-FDMA) and/or OFDMA are applied to the uplink.

[097] OFDMA is a multi-carrier communication scheme for performing communication by dividing a frequency bandwidth into a plurality of narrow frequency bandwidths (subcarriers) and mapping data to each subcarrier. SC-FDMA is a single-carrier communication scheme for mitigating interference between terminals by dividing the system bandwidth into bands formed with one or more continuous resource blocks per terminal, and allowing a plurality of terminals to utilize mutually different bands. Note that uplink and downlink radio access schemes are not limited to these combinations, and other radio access schemes may be utilized.

[098] In the radio communication system 1, a downlink shared channel (PDSCH (Physical Downlink Shared Channel)), which is used by each user terminal 20 on a shared basis, a broadcast channel (PBCH (Physical Broadcast Channel)), L1/L2 downlink control channels, and so on are used as downlink channels. User data, upper layer control information, and SIBs (System Information Blocks) are communicated on the PDSCH. Also, the MIB (Master Information Block) is communicated on the PBCH.

[099] The L1/L2 downlink control channels include a PDCCH (Physical Downlink Control Channel), an EPDCCH (Enhanced Physical Downlink Control Channel), a PCFICH (Physical Control Format Indicator Channel), a PHICH (Physical Hybrid-ARQ Indicator Channel), and so on. The downlink control information (DCI), including the PDSCH and/or PUSCH scheduling information, is communicated over the PDCCH.

[0100] Note that scheduling information may be reported in DCIs. For example, DCIs for scheduling the receipt of DL data may be referred to as “DL assignment,” and DCIs for scheduling the transmission of UL data may also be referred to as “UL grant.”

[0101] The number of OFDM symbols to be used for the PDCCH is communicated by the PCFICH. HARQ (Hybrid Automatic Repeat Request) delivery acknowledgement information (also referred to as, e.g., “retransmission control information,” “HARQ-ACKs,” “ACK/NACKs,” etc.) in response to the PUSCH is transmitted by the PHICH. The EPDCCH is frequency-division multiplexed with the PDSCH (Downlink Shared Data Channel) and used to communicate DCI and so on, like the PDCCH.

[0102] In the radio communication system 1, an uplink shared channel (PUSCH (Physical Uplink Shared Channel)), which is used by each user terminal 20 on a shared basis, an uplink control channel (PUCCH (Physical Uplink Control Channel)), a random access channel (PRACH (Physical Random Access Channel)), and so on are used as uplink channels. User data, upper layer control information, and so on are communicated over the PUSCH. Also, over the PUCCH, downlink radio quality information (CQI (Channel Quality Indicator)), delivery acknowledgement information, scheduling requests (SRs), and so on are communicated. Through the PRACH, random access preambles for establishing connections with cells are communicated.

[0103] In the radio communication system 1, the cell-specific reference signals (CRSs), the channel status information reference signals (CSI-RSs), the demodulation reference signals (DMRSs), the positioning reference signals (PRSs), and so on are communicated as downlink reference signals. Also, in the radio communication system 1, the measurement reference signals (SRS (Sounding Reference Signal)), the demodulation reference signal (DMRS), and so on are communicated as uplink reference signals. Note that the DMRS may be referred to as the “user terminal-specific reference signal (UE-Specific Reference Signal). Also, the reference signals to be communicated are by no means limited to these.

(Radio Base Station)

[0104] FIG. 9 is a diagram to show an example of a general structure of a radio base station according to an embodiment of the present invention. A radio base station 10 has a plurality of transmit/receive antennas 101, amplification sections 102, transmit/receive sections 103, a baseband signal processing section 104, a call processing section 105, and a communication path interface 106. Note that one or more transmit/receive antennas 101, amplification sections 102, and transmit/receive sections 103 may be provided.

[0105] User data to be transmitted from the radio base station 10 to a user terminal 20 on the downlink are input from the upper station apparatus 30 to the baseband signal processing section 104 via the communication path interface 106.

[0106] In the baseband signal processing section 104, user data is subjected to transmission processes including a PDCP (Packet Data Convergence Protocol) layer process, user data splitting and coupling, RLC (Radio Link Control) layer transmission processes such as RLC retransmission control, MAC (Medium Access Control) retransmission control (e.g., a HARQ (Hybrid Automatic Repeat Request) transmission process), scheduling, transport format selection, channel coding, an inverse fast Fourier transform (IFFT) process, and a precoding process, and the result is forwarded to each transmit/receive section 103. In addition, downlink control signals are also subjected to transmission processes such as channel coding and an inverse fast Fourier transform, and forwarded to each transmit/receive section 103.

[0107] Baseband signals that are pre-coded and output from baseband signal processing section 104 on a per-antenna basis are converted to a radio frequency band in transmission/reception sections 103, and then transmitted. The radio frequency signals having been subjected to frequency conversion in transmission/reception sections 103 are amplified in amplification sections 102, and transmitted from transmission/reception antennas 101. Transmission/reception sections 103 may be constituted by transmitters/receivers, transmission/reception circuits, or transmission/reception apparatus that may be described based on the general understanding of the technical field to which the present invention pertains. Note that a transmission/reception section 103 may be structured as a transmission/reception section in one entity, or may be constituted by a transmission section and a reception section.

[0108] Further, as for uplink signals, the radio frequency signals that are received at the transmit/receive antennas 101 are each amplified in the amplification sections 102. The transmit/receive sections 103 receive the uplink signals amplified in the amplification sections 102. The received signals are converted into the baseband signal through frequency conversion in the transmit/receive sections 103 and output to the baseband signal processing section 104.

[0109] In the baseband signal processing section 104, the user data that is included in the uplink signals that are input are subjected to a fast Fourier transform (FFT) process, an inverse discrete Fourier transform (IDFT) process, error correction decoding, a MAC retransmission control reception process, and RLC layer and PDCP layer reception processes, and forwarded to the upper station apparatus 30 through the communication path interface 106. The call processing section 105 performs call processing of communication channels (such as setting and releasing of communication channels), manages the state of the radio base stations 10, and manages the radio resources.

[0110] The communication path interface section 106 transmits and receives signals to and from the upper station apparatus 30 via a predetermined interface. Also, the communication path interface 106 may transmit and receive signals (backhaul signaling) with other radio base stations 10 via an interbase station interface (which is, for example, fiber optics that is CPRI (Common Public Radio Interface) compliant, the X2 interface, etc.).

[0111] Furthermore, the transmit/receive section 103 may transmit, to the user terminal 20, DL control information indicating the relationship between the timing at which the user terminal 20 receives DL control information (timing for the radio base station 10 to transmit DL control information), the timing at which the user terminal 20 receives the DL data (timing for the radio base station 10 to transmit the DL data), and the timing at which the user terminal 20 transmits the delivery acknowledgement information (e.g., HARQ-ACK) (timing at which the radio base station 10 receives the delivery acknowledgement information).

[0112] Furthermore, the transmit/receive section 103 may transmit the DL data at the time of transmitting DL data. Furthermore, the transmit/receive section 103 may receive the relevant delivery acknowledgement information at the time the delivery acknowledgement information is received.

[0113] FIG. 10 is a diagram for showing an example of a functional structure of a radio base station according to an embodiment of the present invention. Note that although this example primarily shows functional blocks that belong to the characteristic parts of the present embodiment, the radio base station 10 has other functional blocks that are also necessary for radio communication.

[0114] The baseband signal processing section 104 at least has a control section (scheduler) 301, a transmit signal generation section 302, a mapping section 303, a received signal processing section 304, and a measurement section 305. Note that these configurations only have to be included in the radio base station 10, and some or all of these configurations may not be included in the baseband signal processing section 104.

[0115] The control section (scheduler) 301 controls the entire radio base station 10. The control section 301 may consist of a controller, a control circuit or control apparatus which may be described based on the general understanding of the technical field to which the present invention belongs.

[0116] Control section 301, for example, controls signal generation in transmit signal generation section 302, signal allocation by mapping section 303, and so on. In addition, control section 301 controls signal receiving processes in received signal processing section 304, signal measurements in measurement section 305, and so on.

[0117] Control section 301 controls the scheduling (e.g., resource allocation) of system information, downlink data signals (e.g., signals transmitted on the PDSCH), and downlink control signals (e.g., signals transmitted on the PDCCH and/or EPDCCH, such as delivery acknowledgement information). In addition, control section 301 controls the generation of downlink control signals, downlink data signals, and so on, based on the results of deciding whether or not retransmission control is required for uplink data signals, and so on. In addition, control section 301 controls the scaling of synchronization signals (e.g., PSS (Primary Synchronization Signal)/SSS (Secondary Synchronization Signal)), downlink reference signals (e.g., CRSs, CSI-RSs, DMRSs, and so on), and so on.

[0118] Control section 301 also controls the scheduling of uplink data signals (e.g., signals transmitted on the PUSCH), uplink control signals (e.g., signals transmitted on the PUCCH and/or PUSCH, such as delivery acknowledgement information), random access preambles (e.g., signals transmitted on the PRACH), and uplink reference signals.

[0119] The transmission signal generation section 302 generates downlink signals (downlink control signals, downlink data signals, downlink reference signals, and so on) based on commands from the control section 301, and outputs these signals to the mapping section 303. The transmission signal generation section 302 may be constituted by a signal generator, a signal generation circuit, or a signal generation apparatus, which can be described based on the general understanding of the technical field to which the present invention belongs.

[0120] For example, the transmit signal generation section 302 generates DL assignments, which report downlink data allocation information, and/or UL grants, which report uplink data allocation information, based on commands from the control section 301. The DL assignments and UL grants are both DCI, conforming to DCI formats. Further, the downlink data signals are subjected to the encoding process, the modulation process, and so on, using encoding rates and modulation schemes selected based on, for example, channel state information (CSI) of each user terminal 20.

[0121] The mapping section 303 maps the downlink signals generated in the transmission signal generation section 302 to predetermined radio resources based on the commands from the control section 301, and outputs these to the transmission/reception sections 103. The mapping section 303 may be constituted by a mapper, a mapping circuit or a mapping apparatus which may be described based on the general understanding of the technical field to which the present invention belongs.

[0122] The received signal processing section 304 performs reception processes (e.g., demapping, demodulation, decoding, and so on) of received signals that are input from the transmission/reception sections 103. Here, the received signals include, for example, uplink transmitted signals from the user terminal 20 (uplink control signals, uplink data signals, uplink reference signals, etc.). For the received signal processing section 304, a signal processor, a signal processing circuit, or a signal processing apparatus that can be described based on the general understanding of the technical field to which the present invention belongs can be utilized.

[0123] The received signal processing section 304 outputs the decoded information acquired through the receiving processes to the control section 301. For example, when a PUCCH to contain a HARQ-ACK is received, the received signal processing section 304 outputs this HARQ-ACK to the control section 301. Furthermore, the received signal processing section 304 outputs the received signals and/or the signals after the receiving processes to the measurement section 305.

[0124] The measuring section 305 conducts measurements with respect to the received signal. The measuring section 305 may consist of a meter, a measuring circuit or a measuring apparatus which may be described based on the general understanding of the technical field to which the present invention belongs.

[0125] For example, measurement section 305 may perform RRM (Radio Resource Management) measurements, CSI (Channel State Information) measurements, and so on, based on received signals. Measurement section 305 may 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), etc.), signal strength (e.g., RSSI (Received Signal Strength Indicator)), transmission path information (e.g., CSI), and so on. The measurement results may be output to control section 301.

[0126] Furthermore, the control section 301 may control transmission of DL control information, transmission of DL data, and receipt of delivery acknowledgment information in response to the DL data.

[0127] Furthermore, the control section 301 may schedule the DL data, determine the timing of the delivery acknowledgement information in response to the DL data, and generate DL control information based on the result.

[0128] (User Terminal) FIG. 11 is a diagram for showing an example of a general structure of a user terminal according to an embodiment of the present invention. A user terminal 20 has a plurality of transmit/receive antennas 201, amplification sections 202, transmit/receive sections 203, a baseband signal processing section 204, and an application section 205. Note that one or more transmit/receive antennas 201, amplification sections 202, and transmit/receive sections 203 may be provided.

[0129] Radio frequency signals that are received at the transmit/receive antennas 201 are amplified in the amplification sections 202. The transmit/receive sections 203 receive the downlink signals amplified in the amplification sections 202. The received signals are subjected to frequency conversion and converted into the baseband signal in the transmit/receive sections 203, and output to the baseband signal processing section 204. A transmit/receive section 203 may be constituted by a transmitter/receiver, a transmit/receive circuit, or transmit/receive apparatus, which may be described based on the general understanding of the technical field to which the present invention pertains. Note that a transmit/receive section 203 may be structured as a transmit/receive section in one entity, or may be constituted by a transmit section and a receive section.

[0130] The baseband signal processing section 204 performs, for the baseband signal that is input, an FFT process, error correction decoding, a retransmission control reception process, and so on. The downlink user data is forwarded to the application section 205. The application section 205 performs processes related to the upper layers above the physical layer and the MAC layer, and so on. In addition, in the downlink data, broadcast information may also be forwarded to the application section 205.

[0131] Further, uplink user data is input from application section 205 to baseband signal processing section 204. Baseband signal processing section 204 performs a relay control transmission process (e.g., a HARQ transmission process), channel coding, precoding, a discrete Fourier transform (DFT) process, an IFFT process, and so on, and the result is forwarded to transmission/reception section 203. Baseband signals that are output from baseband signal processing section 204 are converted to a radio frequency band in transmission/reception sections 203 and transmitted. Radio frequency signals that are subjected to frequency conversion in transmission/reception sections 203 are amplified in amplification sections 202 and transmitted from transmission/reception antennas 201.

[0132] Furthermore, the transmit/receive section 203 may receive DL control information. Furthermore, the transmit/receive section 203 may receive DL data staggered by the DL control information. Furthermore, the transmit/receive section 203 may transmit delivery acknowledgement information in response to the DL data.

[0133] FIG. 12 is a diagram for showing an example of a functional structure of a user terminal according to an embodiment of the present invention. Note that although this example mainly shows functional blocks that belong to the characteristic parts of the present embodiment, the user terminal 20 has other functional blocks that are also necessary for radio communication.

[0134] The baseband signal processing section 204 provided in the user terminal 20 at least has a control section 401, a transmit signal generation section 402, a mapping section 403, a received signal processing section 404, and a measurement section 405. Note that these configurations only have to be included in the user terminal 20, and some or all of these configurations may not be included in the baseband signal processing section 204.

[0135] The control section 401 controls the entire user terminal 20. For the control section 401, a controller, a control circuit, or a control apparatus that can be described based on the general understanding of the technical field to which the present invention belongs can be used.

[0136] Control section 401, for example, controls the generation of signals in transmit signal generation section 402, the distribution of signals by mapping section 403, and so on. In addition, control section 401 controls signal reception processes in received signal processing section 404, signal measurements in measurement section 405, and so on.

[0137] The control section 401 acquires the downlink control signals and downlink data signals transmitted from the radio base station 10 through the received signal processing section 404. The control section 401 controls the generation of uplink control signals and/or uplink data signals based on the results of deciding whether or not retransmission control is required for the downlink control signals and/or downlink data signals, and so on.

[0138] Furthermore, when various types of information reported from the radio base station 10 are acquired through the received signal processing section 404, the control section 401 may update the parameters to be used in the control based on this information.

[0139] The transmission signal generation section 402 generates uplink signals (uplink control signals, uplink data signals, uplink reference signals, etc.) based on commands from the control section 401 and outputs these signals to the mapping section 403. The transmission signal generation section 402 may be constituted by a signal generator, a signal generation circuit or a signal generation apparatus which can be described based on the general understanding of the technical field to which the present invention belongs.

[0140] For example, transmit signal generation section 402 generates uplink control signals related to delivery acknowledgement information and/or channel state information (CSI) based on commands from control section 401. Also, transmit signal generation section 402 generates uplink data signals based on commands from control section 401. For example, when a UL grant is included in a downlink control signal that is reported from radio base station 10, control section 401 commands transmit signal generation section 402 to generate an uplink data signal.

[0141] The mapping section 403 maps the uplink signals generated in the transmission signal generation section 402 to the radio resources based on the commands from the control section 401, and outputs the result to the transmission/reception sections 203. The mapping section 403 may be constituted by a mapper, a mapping circuit or a mapping apparatus which may be described based on the general understanding of the technical field to which the present invention belongs.

[0142] The received signal processing section 404 performs reception processes (e.g., demapping, demodulation, decoding, and so on) of received signals that are input from the transmission/reception sections 203. Here, the received signals include, for example, downlink signals (downlink control signals, downlink data signals, downlink reference signals, and so on) that are transmitted from the radio base station 10. The received signal processing section 404 may be constituted by a signal processor, a signal processing circuit, or a signal processing apparatus that can be described based on the general understanding of the technical field to which the present invention belongs. Also, the received signal processing section 404 may constitute the reception section according to the present invention.

[0143] The received signal processing section 404 outputs the decoded information acquired through the reception processes to the control section 401. The received signal processing section 404 outputs, for example, broadcast information, system information, RRC signaling, DCI, and so on, to the control section 401. Also, the received signal processing section 404 outputs the received signals and/or the signals after the reception processes to the measurement section 405.

[0144] The measuring section 405 conducts measurements with respect to the received signals. The measuring section 405 may consist of a meter, a measuring circuit or measuring apparatus which may be described based on the general understanding of the technical field to which the present invention belongs.

[0145] For example, measurement section 405 may perform RRM measurements, CSI measurements, and so on, based on received signals. Measurement section 405 may measure received power (e.g., RSRP), received quality (e.g., RSRQ, SINR, etc.), signal strength (e.g., RSSI), transmission path information (e.g., CSI), and so on. The measurement results may be output to control section 401.

[0146] Furthermore, the control section 401 may control the receipt of scheduled DL data in accordance with the DL control information and the transmission of delivery acknowledgement information in response to the DL data. The DL control information may indicate a relationship between the timing of receiving the DL control information, the timing of receiving the DL data, and the timing of transmitting delivery acknowledgement information.

[0147] Furthermore, the DL control information may indicate, for each slot, the relationship between the timing of receiving the DL control information, the timing of receiving the DL data, and the timing of transmitting the delivery acknowledgement information.

[0148] Further, the DL control information may indicate the relationship between the timing of receiving DL control information (e.g., time difference, k) and the timing of receiving DL data, and the timing of receiving DL control information and the timing of transmitting delivery acknowledgement information (e.g., time difference, m) (e.g., HARQ-ACK timing setting method 1, 1-1, and 2-1). Further, the DL control information may indicate the relationship between the timing of receiving DL control information (e.g., time difference, k) and the timing of receiving DL data, and the timing of receiving DL control information and the timing of transmitting delivery acknowledgement information (e.g., time difference, m) (e.g., HARQ-ACK timing setting method 2, 1-2, and 2-2).

[0149] Furthermore, control section 401 may control receipt of DL data in a slot located after the slot in which the DL control information is received.

[0150] Further, the control section 401 may exercise control, based on the DL control information, so that a plurality of DL data are respectively received over a plurality of slots, and delivery acknowledgement information in response to the plurality of DL data is transmitted in 1 slot.

[0151] Furthermore, the control section 401 may exercise control, based on the DL control information, so that a plurality of DL data are respectively received over multiple slots, and multiple delivery acknowledgement information are transmitted over multiple slots, respectively.

[0152] Furthermore, the relationship between the timing of receiving DL data and the timing of transmitting delivery acknowledgement information may be determined based on the information indicating the capability of the user terminal 20.

[0153] (Hardware Structure) Note that the block diagrams that were used to describe the above embodiments show blocks in functional units. These functional blocks (components) can be implemented in arbitrary combinations of hardware and/or software. Also, the means for implementing each functional block is not particularly limited. That is, each functional block can be executed by a piece of apparatus that is physically and/or logically aggregated, or it can be executed by directly and/or indirectly connecting two or more physically and/or logically separate pieces of apparatus (through wire or wirelessly, for example) and utilizing these multiple pieces of apparatus.

[0154] For example, the radio base station, user terminals, and so on according to embodiments of the present invention may function as a computer that executes the processes of the radio communication method of the present invention. FIG. 13 is a diagram to show an example hardware structure of a radio base station and a user terminal according to an embodiment of the present invention. Physically, the radio base stations 10 and user terminals 20 described above may be formed as a computer apparatus that includes a processor 1001, a memory 1002, a storage 1003, communication apparatus 1004, input apparatus 1005, output apparatus 1006, and a bus 1007.

[0155] Note that in the following description, the word "apparatus" may be replaced by "circuit," "device," "unit," and so on. Note that the hardware structure of a radio base station 10 and a user terminal 20 may be designed to include one or more of each apparatus shown in the drawings, or may be designed to not include part of the apparatus.

[0156] For example, although only one processor 1001 is shown, a plurality of processors may be provided. Furthermore, processes may be implemented with one processor, or processes may be implemented sequentially, or in different ways, on one or more processors. Note that processor 1001 may be implemented with one or more chips.

[0157] Each function of the radio base station 10 and the user terminal 20 is implemented by reading predetermined software (program) in hardware such as the processor 1001 and the memory 1002, and controlling the calculations in the processor 1001, the communication in the communication apparatus 1004, and the reading and/or writing of data in the memory 1002 and the storage 1003.

[0158] Processor 1001 may control the entire computer, for example, by running an operating system. Processor 1001 may be configured with a central processing unit (CPU), which includes interfaces with peripheral apparatus, control apparatus, computing apparatus, a register, and so on. For example, baseband signal processing section 104 (204), call processing section 105 described above, and others may be implemented by processor 1001.

[0159] Furthermore, the processor 1001 reads programs (program codes), software modules, data, and so on from the storage 1003 and/or the communication apparatus 1004, into the memory 1002, and executes various processes therein. As for the programs, programs that enable computers to perform at least part of the operations of the embodiments described above may be used. For example, the control section 401 of the user terminals 20 may be implemented by the control programs that are stored in the memory 1002 and that operate on the processor 1001, and other functional blocks may be implemented in the same manner.

[0160] Memory 1002 is a computer-readable recording medium, and may be comprised of, for example, at least one of a ROM (Read Only Memory), an EPROM (Erasable Programmable ROM), an EEPROM (Electrically Readable EPROM), a RAM (Random Access Memory), and/or other suitable storage media. Memory 1002 may be referred to as a “register,” a “cache,” a “main memory” (primary storage device), and so on. Memory 1002 may store executable programs (program codes), software modules, and so on for implementing radio communication methods according to embodiments of the present invention.

[0161] Storage 1003 is a computer-readable recording medium, and may be comprised of, for example, at least one of a floppy disk, a floppy disk (trademark), a magneto-optical disk (e.g., a compact disk (CD-ROM (Compact Disk ROM) and so on), a digital versatile disk, a Blu-ray Disc (trademark)), a removable disk, a hard disk drive, a smart card, a flash memory device (e.g., a card, a stick, a key drive, etc.), a magnetic stripe, a database, a server, and/or other suitable storage media. Storage 1003 may be referred to as a “secondary storage apparatus.”

[0162] Communication apparatus 1004 is hardware (transmission/receiving apparatus) for enabling communication between computers using wired and/or wireless networks, and may be referred to as, for example, a “network device,” a “network controller,” a “network card,” a “communication module,” and so on. Communication apparatus 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, and so on so as to realize, for example, frequency division duplex (FDD) and/or time division duplex (TDD). For example, the transmit/receive antennas 101 (201), amplification sections 102 (202), transmit/receive sections 103 (203), communication path interface 106, and so on described above may be implemented by communication apparatus 1004.

[0163] Input apparatus 1005 is an input device for receiving input from the outside (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, and so on). Output apparatus 1006 is an output device for allowing sending output to the outside (e.g., a display, a speaker, an LED (Light Emitting Diode) lamp, and so on). Note that input apparatus 1005 and output apparatus 1006 may be provided in an integrated structure (e.g., a touch panel).

[0164] Furthermore, these parts of the apparatus, including the processor 1001, the memory 1002, and so on, are connected by the bus 1007 in order to communicate information. The bus 1007 may be formed with a single bus, or may be formed with buses that vary between parts of the apparatus.

[0165] Also, the radio base station 10 and the user terminal 20 may be structured to include hardware such as a microprocessor, a digital signal processor (DSP), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), an FPGA (Field Programmable Gate Array), and so on, and some or all of the functional blocks may be implemented by the hardware. For example, the processor 1001 may be implemented with at least one of these pieces of hardware.

[0166] (Variations) Note that terminology used in this specification and terminology that is necessary to understand this specification may be replaced by other terms that carry the same or similar meanings. For example, “channels” and/or “symbols” may be replaced by “signals (or “signaling”)”. Also, “signals” may be “messages”. A reference signal may be abbreviated as an “RS”, and may be referred to as a “pilot”, a “pilot signal”, and so on, depending on which standard applies. Furthermore, a “component carrier (CC)” may be referred to as a “cell”, a “frequency carrier”, a “carrier frequency”, and so on.

[0167] Furthermore, a radio frame may be comprised of one or more periods (frames) in the time domain. Each of the one or more periods (frames) constituting a radio frame may be referred to as a “subframe”. Furthermore, a subframe may be comprised of one or more slots in the time domain. A subframe may be a fixed time duration (e.g., 1 ms) not dependent on numerology.

[0168] Furthermore, a slot may be comprised of one or more symbols in the time domain symbols (OFDM (Orthogonal Frequency Division Multiplexing), SC-FDMA (Single Carrier Frequency Division Multiple Access) symbols, and so on). Also, a slot may be a unit of time based on numerology. Also, a slot may include a plurality of minislots. Each minislot may consist of one or more symbols in the time domain. Also, a minislot may be referred to as a “subslot”.

[0169] A radio frame, a subframe, a slot, a minislot, and a symbol all represent the unit of time in signal communication. A radio frame, a subframe, a slot, a minislot, and a symbol may each be called by other applicable names. For example, a subframe may be referred to as a “transmission time interval (TTI),” or a plurality of consecutive subframes may be referred to as a “TTI,” or a slot or minislot may be referred to as a “TTI.” That is, a subframe and/or a TTI may be a subframe (1 ms) in existing LTE, may be a period shorter than 1 ms (e.g., one to thirteen symbols), or may be a period of time longer than 1 ms. Note that the unit for representing the TTI may be referred to as a “slot,” a “minislot,” and so on, rather than a “subframe.”

[0170] Here, a TTI refers to the minimum time unit of scheduling in radio communication, for example. For example, in LTE systems, a radio base station schedules the radio resources (such as the frequency bandwidth and transmission power that can be used at each user terminal) to allocate each user terminal in units of TTI. Note that the definition of TTIs is not limited to this.

[0171] The TTI may be the unit of time for transmitting channel-coded data packets (transport blocks), code blocks, and/or code words, or it may be the unit of processing in scheduling, link adaptation, and so on. Note that when a TTI is provided, the period of time (e.g., the number of symbols) into which transport blocks, code blocks, and/or code words are actually mapped may be shorter than that of the TTI.

[0172] Note that when a slot or a minislot is referred to as a “TTI,” one or more TTIs (i.e., one or more slots or one or more minislots) may be the minimum scheduling time unit. Also, the number of slots (the number of minislots) to constitute this minimum scheduling time unit may be controlled.

[0173] A TTI having a time duration of 1 ms may be referred to as a “normal TTI” (TTI in LTE Rel. 8 to 12), a “long TTI”, a “normal subframe”, a “long subframe”, and so on. A TTI that is shorter than a normal TTI may be referred to as a “shortened TTI”, a “short TTI”, “a partial TTI (or a “fractional TTI”)”, a “shortened subframe”, a “short subframe”, a “minislot”, “a subslot”, and so on.

[0174] Note that a long TTI (e.g., a normal TTI, a subframe, etc.) may be replaced with a TTI having a time duration exceeding 1 ms, and a short TTI (e.g., a shortened TTI) may be replaced with a TTI having a TTI length less than the TTI length of a long TTI and not less than 1 ms.

[0175] A resource block (RB) is the unit of resource allocation in the time domain and the frequency domain, and may include one or a plurality of consecutive subcarriers in the frequency domain. Also, an RB may include one or more symbols in the time domain, and may be a slot, a minislot, a subframe, or a TTI in length. A TTI and a subframe may be comprised of one or more resource blocks. Note that one or more RBs may be referred to as a “physical resource block (PRB (Physical RB))”, a “subcarrier group (SCG)”, a “resource element group (REG)”, a “PRB pair”, an “RB pair”, and so on.

[0176] Furthermore, a resource block may be comprised of one or more resource elements (REs). For example, an RE may be a radio resource region of one subcarrier and one symbol.

[0177] Note that the structures of radio frames, subframes, slots, minislots, symbols, and so on described above are merely examples. For example, settings pertaining to the number of subframes included in a radio frame, the number of slots included in a subframe, the number of minislots included in a slot, the number of symbols and RBs included in a slot or a minislot, the number of subcarriers included in an RB, the number of symbols in a TTI, the symbol duration, the length of cyclic prefixes (CPs), and so on may be variably changed.

[0178] Also, the information and parameters described in this specification may be represented in absolute values or in relative values with respect to predetermined values, or may be represented in other information formats. For example, radio resources may be specified by predetermined indices. In addition, equations for utilizing these parameters and so on may be used in addition to those explicitly disclosed in this specification.

[0179] The names used for parameters and so on in this specification are not limiting in any way. For example, since various channels (PUCCH (Physical Uplink Control Channel), PDCCH (Physical Downlink Control Channel), and so on) and information elements may be identified by any suitable names, the various names assigned to these individual channels and information elements are not limiting in any way.

[0180] The information, signals, and/or other information described in this specification may be represented using a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, and chips, all of which may be referenced throughout the description herein, may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or photons, or any combination thereof.

[0181] Also, information, signals, and so on may be emitted from higher layers to lower layers and/or from lower layers to higher layers. Information, signals, and so on may be input and emitted through a plurality of network nodes.

[0182] The information, signals, and so on that are input and/or output may be stored in a specific location (e.g., memory) or may be managed using a management table. The information, signals, and so on to be input and/or output may be overwritten, updated, or appended. The information, signals, and so on that are output may be suppressed. The information, signals, and so on that are input may be transmitted to other pieces of apparatus.

[0183] Information reporting is not limited to the aspects/embodiments described in this specification, and other methods may also be utilized. For example, information reporting may be implemented using physical layer signaling (e.g., Downlink Control Information (DCI), Uplink Control Information (UCI), higher layer signaling (e.g., RRC (Radio Resource Control), broadcast information (the Master Information Block (MIB), System Information Blocks (SIBs), and so on), MAC (Medium Access Control) signaling, and so on), and other signals and/or combinations thereof.

[0184] Note that physical layer signaling may be referred to as “L1/L2 (Layer 1/Layer 2) control information (L1/L2 control signals)”, “L1 control information (L1 control signal)”, and so on. Also, RRC signaling may be referred to as “RRC messages”, and may be, for example, an RRC connection setup message, RRC connection reconfiguration message, and so on. Also, MAC signaling may be conveyed using, for example, MAC control elements (MAC CEs (Control Elements)).

[0185] Also, reporting predetermined information (e.g., reporting information to the effect that “X is valid”) need not necessarily be sent explicitly, and may be sent implicitly (e.g., by not reporting this piece of information, or by reporting a different piece of information).

[0186] Decisions may be made on values represented by a bit (0 or 1), may be made on boolean values representing true or false, or may be made by comparing numeric values (e.g., against a predetermined value).

[0187] Software, whether referred to as “software,” “firmware,” “middleware,” “microcode,” or “hardware description language,” or called by other names, should be construed broadly to mean instructions, instruction sets, code, code segments, program codes, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, and so on.

[0188] Also, software, commands, information, and so on may be transmitted and received through communication media. For example, when software is transmitted from a website, a server, or other remote sources using wired technologies (coaxial cables, fiber optic cables, twisted pair cables, digital subscriber lines (DSL), and so on) and/or wireless technologies (infrared radiation, microwaves, and so on), these wired technologies and/or wireless technologies are also included in the definition of communication media.

[0189] The terms “system” and “network” as used herein are used interchangeably.

[0190] As used herein, the terms “base station (BS),” “radio base station,” “eNB,” “gNB,” “cell,” “sector,” “cell group,” “carrier,” and “component carrier” may be used interchangeably. A base station may be referred to as a “fixed station,” “NodeB,” “eNoB (eNB),” “access point,” “transmit point,” “receive point,” “femtocell,” “small cell,” and so on.

[0191] A base station may accommodate one or more (e.g., 3) cells (also referred to as “sectors”). When a base station accommodates a plurality of cells, the entire coverage area of the base station may be partitioned into multiple smaller areas, and each smaller area may provide communication services through base station subsystems (e.g., small indoor base stations (RRHs)). The term “cell” or “sector” refers to part or all of the coverage area of a base station and/or a base station subsystem that provides communication services within this coverage.

[0192] As used herein, the terms “mobile station (MS),” “user terminal,” “user equipment (UE),” and “terminal” may be used interchangeably. A base station may be referred to as a “fixed station,” “NodeB,” “eNodeB (eNB),” “access point,” “transmitting point,” “receiving point,” “femtocell,” “small cell,” and so on.

[0193] A mobile station may be referred to, by one skilled in the art, as a “subscriber station”, “mobile unit”, “subscriber unit”, “wireless unit”, “remote unit”, “mobile device”, “wireless device”, “wireless communication device”, “remote device”, “mobile subscriber station”, “access terminal”, “mobile terminal”, “wireless terminal”, “remote terminal”, “handset”, “user agent”, “mobile client”, “client”, or some other suitable terms.

[0194] Furthermore, radio base stations in this specification may be interpreted as user terminals. For example, each aspect/embodiment of the present invention may be applied to a configuration in which communication between a radio base station and a user terminal is replaced with communication between a plurality of user terminals (D2D (Device to Device)). In this case, user terminals 20 may have the functions of radio base stations 10 described above. Furthermore, terms such as “uplink” and “downlink” may be interpreted as “side”. For example, an uplink channel may be interpreted as a side channel.

[0195] Likewise, user terminals in this specification may be interpreted as radio base stations. In this case, radio base stations 10 may have the functions of user terminals 20 described above.

[0196] Certain actions that have been described in this specification to be performed by the base station may, in some cases, be performed by superior nodes (higher nodes). In a network comprised of one or more network nodes with base stations, it is clear that various operations that are performed to communicate with terminals may be performed by base stations, one or more network nodes (e.g., MMEs (Mobility Management Entities), S-GWs (Serving Gateways), and so on may be possible, but these are not limiting) in addition to the base stations, or combinations thereof.

[0197] The aspects/embodiments illustrated in this specification may be used individually or in combinations, which may be changed depending on the mode of implementation. The order of processes, sequences, flowcharts, and so on that have been used to describe the aspects/embodiments herein may be rearranged, provided that no inconsistencies arise. For example, although several methods have been illustrated in this specification with various component steps in exemplary orders, the specific orders that are illustrated here are in no way limiting.

[0198] Aspects/embodiments illustrated in this specification may be applied to systems utilizing LTE (Long Term Evolution), LTE-A (LTE-Advanced), LTE-B (LTE-Beyond), SUPER 3G, IMT-Advanced, 4G (4th generation mobile system), 5G (5th generation mobile system), FRA (Future Radio Access), New-RAT (Radio Access Technology), NR (New Radio), NX (New Radio Access), FX (Future Generation Radio Access), GSM (Global System for Mobile Communications) (registered trademark), CDMA 2000, UMB (Ultra Mobile Wideband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, UWB (Ultra Wideband), Bluetooth (registered trademark), and other appropriate radio communication methods, and/or next-generation systems that are enhanced based on these.

[0199] The phrase “based on” as used in this specification 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.”

[0200] Reference to elements with designations such as “first,” “second,” and so on, as used herein, does not generally limit the number/quantity or order of these elements. These designations are used solely for convenience, as a method of distinguishing between two or more elements. Thus, reference to the first and second elements does not imply that only two elements may be used, or that the first element must precede the second element in any way.

[0201] The terms “judge” and “determine,” as used herein, can encompass a wide variety of actions. For example, to “judge” and “determine,” as used herein, can be interpreted to mean making judgments and determinations related to calculating, computing, processing, deriving, investigating, searching (e.g., searching a table, database, or some other data structure), ascertaining, and so on. Furthermore, to “judge” and “determine,” as used herein, can be interpreted to mean making judgments and determinations related to receiving (e.g., receiving information), transmitting (e.g., transmitting information), inputting, outputting, accessing (e.g., accessing data in a memory), and so on. Furthermore, to “judge” and “determine,” as used herein, can be interpreted to mean making judgments and determinations related to resolving, selecting, choosing, establishing, comparing, and so on. In other words, to “judge” and “determine,” as used here, can be interpreted as making judgments and determinations related to some action.

[0202] As used herein, the terms “connected” and “coupled,” or any variation of these terms, mean all direct or indirect connections or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are “connected” or “coupled” to each other. The coupling or connection between the elements may be physical, logical, or a combination thereof. For example, “connection” may be interpreted as “access.” As used herein, two elements may be considered “connected” or “coupled” to each other using one or more electrical wires, cables, and/or printed electrical connections, and, as various non-limiting and non-inclusive examples, using electromagnetic energy, such as electromagnetic energy having wavelengths in the radio frequency, microwave regions, and optical regions (both visible and invisible).

[0203] When terms such as “include,” “comprise,” and variations thereof are used in this specification or the claims, these terms are intended to be inclusive, in a manner similar to the way the term “provide” is used. Furthermore, the term “or” as used in this specification or the claims is intended not to be an exclusive disjunction.

[0204] Now, although the present invention has been described in detail above, it should be obvious to one skilled in the art that the present invention is not limited to the embodiments described herein. The present invention may be implemented with various corrections and in various modifications, without departing from the spirit and scope of the present invention defined by the recitals of the claims. Accordingly, the description contained herein is provided only for the purpose of explaining examples, and should in no way be construed as limiting the present invention in any manner.

Claims (5)

1. A terminal (20) comprising: a receive section (203) configured to receive downlink control information for scheduling a downlink shared channel, the downlink control information including a first field that is associated with a first number of slots from a downlink shared channel reception end slot to a Hybrid Automatic Repeat Request (HARQ) Acknowledgment (ACK) information transmission slot for the downlink shared channel, the downlink control information including a second field that is associated with a second number of slots from a downlink control information reception slot to a downlink shared channel reception slot; and a control section (401) configured to determine the slot for reception of the downlink shared channel based on the second number, characterized in that: the reception section (203) is further configured to receive a higher layer signaling indicating a third number of consecutive slots for the downlink shared channel, the control section (401) is further configured to determine the slot for transmitting HARQ-ACK information based on the first number, the second number, and the third number, a transport block is transmitted on the downlink shared channel in the consecutive slots, the transport block is repeated in each of the consecutive slots, and different redundancy versions are applied to consecutive slots. 2. Terminal (20), according to claim 1, characterized in that the first field indicates the first number. 3. Terminal (20) according to claim 1, characterized in that the receiving section (203) is further configured to receive a plurality of values of the first number via higher layer signaling, and the first field indicates one of the plurality of values. 4. Terminal (20) according to claim 1, characterized in that the control section (401) is further configured to control transmission, in a slot that is the first number of slots after a final slot of the consecutive slots, of HARQ-ACK information for downlink shared channel reception over the consecutive slots. 5. A radio communication method for a terminal (20), comprising: receiving downlink control information for scheduling a downlink shared channel, the downlink control information including a first field that is associated with a first number of slots from a downlink shared channel reception end slot to a Hybrid Automatic Repeat Request (HARQ) Acknowledgment (ACK) information transmission slot for the downlink shared channel, the downlink control information including a second field that is associated with a second number of slots from a downlink control information reception slot to a downlink shared channel reception slot; and determining the slot of the downlink shared channel reception based on the second number, characterized in that: the reception further comprises receiving a higher layer signaling indicating a third number of consecutive slots for the downlink shared channel, the determination further comprises determining the slot for transmitting HARQ-ACK information based on the first number field, the second number, and the third number, a transport block is transmitted on the downlink shared channel in the consecutive slots, the transport block is repeated in each of the consecutive slots, and different redundancy versions are applied to consecutive slots; and HARQ-ACK information for the downlink shared channel reception over the consecutive slots is transmitted in a slot that is the first number of slots after a final slot of the consecutive slots.