Patent Description:
In the UMTS (Universal Mobile Telecommunications System) network, the specifications of long term evolution (LTE) have been drafted for the purpose of further increasing high speed data rates, providing lower latency and so on (see non-patent literature <NUM>). Also, the specifications of LTE-A (also referred to as "LTE-advanced," "LTE Rel. <NUM>," "LTE Rel. <NUM>," or "LTE Rel. <NUM>") have been drafted for further broadbandization and increased speed beyond LTE (also referred to as "LTE Rel. <NUM>" or "LTE Rel. <NUM>"), and successor systems of LTE (also referred to as, for example, "FRA (Future Radio Access)," "<NUM> (5th generation mobile communication system)," "<NUM>+ (plus)," "NR (New Radio)," "NX (New radio access)," "FX (Future generation radio access)," "LTE Rel. <NUM>," "LTE Rel. <NUM>," "LTE Rel. <NUM>" or later versions) are under study.

In existing LTE systems (for example, LTE Rel. <NUM> to <NUM>), downlink (DL) and/or uplink (UL) communication are performed using <NUM>-ms subframes (also referred to as "transmission time intervals (TTIs)" and so on). This subframe is the unit of time it takes to transmit one channel-encoded data packet, and is the processing unit in, for example, scheduling, link adaptation, retransmission control (HARQ (Hybrid Automatic Repeat reQuest)) and so on.

Also, in existing LTE systems (for example, LTE Rel. <NUM> to <NUM>), a user terminal (UE (User Equipment)) transmits uplink control information (UCI) by using a UL control channel (for example, PUCCH (Physical Uplink Control CHannel)) and/or a UL data channel (for example, PUSCH (Physical Uplink Shared CHannel)). The format of this UL control channel is referred to as "PUCCH format" and so on.

UCI includes at least one of a scheduling request (SR), retransmission control information in response to DL data (DL data channel (PDSCH (Physical Downlink Shared CHannel))) (also referred to as "HARQ-ACK (Hybrid Automatic Repeat reQuest-Acknowledgement)," "ACK," "NACK (Negative ACK)" and so on) and channel state information (CSI).

Non-Patent Literature <NUM>: <NPL>
"<NPL>) describes aspects of long-PUCCH for UCI of up to <NUM> bits, namely the time-domain structure (starting position and duration, frequency-hopping boundary and RS positions); frequency-domain structure (frequency-hopping bandwidth); symbol structure for DMRS and UCI; and PUCCH resource allocation (definition of a PUCCH resource, PUCCH resource allocation). "<NPL>) describes agreements made in RAN1#<NUM> meeting for <NUM>-symbol PUCCH with up to <NUM> bits, and the sequence design, the cyclic shift selection for mapping from HARQ-ACK/SR to sequences, and the multiplexing of PUCCH and SRS. "<NPL>) describes agreements made in RAN1#<NUM> meeting on NR short PUCCH for up to 2bits UCI and SR transmission, and the authors' considerations on one-symbol sequence based PUCCH for up to <NUM> bits UCI.

Future radio communication systems (for example, <NUM>, NR, etc.) are expected to realize various radio communication services so as to fulfill mutually varying requirements (for example, ultra-high speed, large capacity, ultra-low latency, etc.).

For example, NR is under study to provide radio communication services referred to as "eMBB (enhanced Mobile Broad Band)," "mMTC (massive Machine Type Communication)," "URLLC (Ultra Reliable and Low Latency Communications)," and so on.

Furthermore, in LTE/NR, studies are underway to use UL control channels of various formats (UL control channel formats). When applying UCI transmission methods in existing LTE systems (LTE Rel. <NUM> or earlier versions) to such future radio communication systems, there is a risk that the coverage, throughput and/or others may deteriorate.

The present invention has been 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, whereby UL control information can be reported properly in future radio communication systems.

According to one aspect of the present invention, there is provided a terminal as set out in Claim <NUM>.

According to another aspect of the present invention, there is provided a radio communication method as set out in Claim <NUM>.

According to another aspect of the present invention, there is provided a system as set out in Claim <NUM>.

According to the present invention, UL control information can be reported properly in future radio communication systems.

Described herein is a user terminal which includes a transmission section that transmits a sequence associated with uplink control information, and a control section that controls selection of a radio resource to use to transmit the sequence, based on a radio resource that is associated with identification information signaled from the radio base station, from among a plurality of radio resources that are designated in configuration information signaled from the radio base station.

Future radio communication systems (for example, LTE Rel. <NUM>, <NUM> and/or later versions, <NUM>, NR, etc.) are under study to introduce multiple numerologies, not a single numerology.

Note that numerology may refer to a set of communication parameters that characterize the design of signals in a given RAT (Radio Access Technology), the design of the RAT and so on, or refer to parameters that relate to the frequency direction and/or the time direction, such as subcarrier spacing (SCS), symbol duration, cyclic prefix duration, subframe duration and so on.

Also, future radio communication systems are being studied to introduce time units (also referred to as "subframes," "slots," "minislots," "subslots," "transmission time intervals (TTIs)," "short TTIs (sTTI)" "radio frames" and so on) that are the same and/or different than existing LTE systems (LTE Rel. <NUM> or earlier versions), while supporting multiple numerologies and so on.

Note that TTIs may represent time units in which transport blocks, code blocks and/or codewords of transmitting/receiving data are transmitted and received. When a TTI is provided, the period of time (for example, the number of symbols) where a transport block, a code block and/or a codeword of data is actually mapped may be shorter than the TTI.

For example, when a given number of symbols (for example, fourteen symbols) constitute a TTI, transmitting/receiving data's transport block, code block and/or codeword can be transmitted and received in a period of one or a given number of symbols in the constituent symbols. If the number of symbols in which a transport block, a code block and/or a codeword of transmitting/receiving data is transmitted and/or received is smaller than the number of symbols constituting a TTI, reference signals, control signals and/or others can be mapped to symbols in the TTI where no data is mapped.

Subframes may serve as time units that have a given time duration (for example, <NUM>), irrespective of which numerology is used by (and/or configured in) a user terminal (for example, UE (User Equipment)).

By contrast with this, slots may serve as time units that depend on the numerology UE uses. For example, if the subcarrier spacing is <NUM> or <NUM>, the number of symbols per slot may be seven or fourteen. When the subcarrier spacing is <NUM> or greater, the number of symbols per slot may be fourteen. In addition, a slot may contain a number of minislots.

For such future radio communication systems, a study is in progress to support a UL control channel (hereinafter also referred to as a "short PUCCH") that is structured to be shorter in duration than PUCCH (Physical Uplink Control CHannel) formats for existing LTE systems (for example, LTE Rel. <NUM> to <NUM>) and/or a UL control channel (hereinafter also referred to as a "long PUCCH") that is structured to have a longer duration than the above short duration.

A short PUCCH (also referred to as a "shortened PUCCH") is formed with a given number of symbols (for example, one symbol, two symbols, or three symbols) provided in a given SCS. In this short PUCCH, uplink control information (UCI) and reference signals (RSs) may be time-division-multiplexed (TDM) or frequency-division-multiplexed (FDM). The RSs may be, for example, the demodulation reference signal (DMRS), which is used to demodulate UCI.

The SCS for each symbol of the short PUCCH may be the same as or higher than the SCS for symbols of data channels (hereinafter also referred to as "data symbols"). The data channels may be, for example, a downlink data channel (PDSCH (Physical Downlink Shared CHannel)), an uplink data channel (PUSCH (Physical Uplink Shared CHannel)) and so on.

Hereinafter, whenever "PUCCH" is simply mentioned, this may be read as "short PUCCH" or "PUCCH in short duration.

PUCCH may be time-division-multiplexed (TDM) and/or frequency-division-multiplexed (FDM) with a UL data channel (hereinafter also referred to as "PUSCH") in the slot. Also, the PUCCH may be time-division-multiplexed (TDM) and/or frequency-division-multiplexed (FDM) with a DL data channel (hereinafter also referred to as "PDSCH") and/or a DL control channel (hereinafter also referred to as "PDCCH (Physical Downlink Control CHannel)") within the slot.

To provide schemes for transmitting short PUCCHs, a DMRS-based PUCCH (DMRS-based transmission or DMRS-based PUCCH), which reports UCI by transmitting UL signals, in which DMRS and UCI are frequency-division-multiplexed (FDM) and/or time-division-multiplexed (TDM), and a sequence-based PUCCH (or sequence-based transmission), which reports UCI by transmitting UL signals using code resources that are associated with UCI values, without using DMRS, are under study.

A DMRS-based PUCCH transmits a PUCCH that contains the RS for demodulating UCI, and therefore may be referred to as "coherent transmission," "coherent design," and so on. A sequence-based PUCCH reports UCI in a PUCCH that does not contain the RS for demodulating UCI, and therefore may be referred to as "non-coherent transmission," "non-coherent design" and so on.

Given that a short PUCCH of one symbol, which is for use for UCI up to two bits, a study is in progress to map a sequence having a sequence length of <NUM>, to <NUM> successive REs (Resource Elements) in PRBs (Physical Resource Blocks). Sequences of sequence length <NUM> or <NUM> may be used as well. A sequence-based PUCCH and other sequences may be multiplexed by CDM (Code Division Multiplexing) or FDM.

Code resources for sequence-based PUCCHs may be resources that can be code-division-multiplexed, and at least one of base sequences, amounts of cyclic shifts (amounts of phase rotations) and OCCs (Orthogonal Cover Codes) may be used. A cyclic shift may be read as a phase rotation.

Information to represent at least one of time resources, frequency resources and code resources for a sequence-based PUCCH may be signaled from the network (NW, which is, for example, a radio base station, a gNodeB, etc.) to UE via higher layer signaling (for example, RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, broadcast information (the MIB (Master Information Block), SIBs (System Information Blocks), etc.), physical layer signaling (for example, DCI) or a combination of these.

Base sequences may be CAZAC (Constant Amplitude Zero Auto-Correlation) sequences (for example, Zadoff-Chu sequences), or may be sequences that are equivalent to CAZAC sequences (for example, CG-CAZAC (Computer-Generated CAZAC) sequences), such as ones specified in 3GPP TS <NUM> §<NUM>. <NUM> (in particular, table <NUM>. <NUM>-<NUM> and table <NUM>. <NUM>-<NUM>). The number of base sequences is, for example, <NUM>.

A case will be described here in which a sequence-based PUCCH transmits two-bit UCI using cyclic shift (CS)). CS can be equally interpreted as the amount of phase rotation, and therefore "the amount of phase rotation" will be used hereinafter interchangeably. Multiple candidates of CS (CS candidates) that are assigned to one UE are referred to as a "CS candidate set" (also referred to as a "cyclic shift amount set," a "cyclic shift amount pattern," a "phase rotation amount candidate set," a "phase rotation amount pattern," etc.).

The sequence length of base sequence is determined by the number of subcarriers M and the number of PRBs (Physical Resource Blocks). As shown in <FIG>, when a sequence-based PUCCH is transmitted using a band of one PRB, the sequence length of the base sequence is <NUM> (= <NUM>×<NUM>). In this case, as shown in <FIG>, twelve amounts of phase rotation α<NUM> to α<NUM>, which are provided at phase intervals of 2π/<NUM> (that is, π/<NUM>) are defined. By applying phase rotations (cyclic shifts) to one base sequence based on amounts of phase rotation α<NUM> to α<NUM>, individually, twelve sequences that are orthogonal to each other (with zero cross-correlation) are acquired. Note that amounts of phase rotation α<NUM> to α<NUM> have only to be determined based on at least one of the number of subcarriers M, the number of PRBs and the sequence length of the base sequence. The CS candidate set may consist of two or more amounts of phase rotation, selected from amounts of phase rotation (cyclic shifts) α<NUM> to α<NUM>. These indices <NUM> to <NUM> of amounts of phase rotation may be referred to as "CS (Cyclic Shift) indices.

The sequence-based PUCCH reports UCI, which includes at least one of an HARQ-ACK (ACK/NACK, A/N), CSI and an SR.

For example, when the UCI is one bit to represent an HARQ-ACK, the UCI values <NUM> and <NUM> may correspond to a "NACK" (Negative ACKnowledgment) and an "ACK" (positive ACKnowledgment), respectively. For example, when the UCI is two bits representing an HARQ-ACK, the UCI values <NUM>, <NUM>, <NUM> and <NUM> may correspond to a "NACK-NACK," a "NACK-ACK," an "ACK- ACK" and an "ACK-NACK," respectively.

For example, when the UCI is two bits, as shown in <FIG>, the UE, given four candidates (UCI candidates, candidate values, etc.) for the two-bit UCI, rotates the phase of a base sequence by selecting an amount of phase rotation that corresponds to the value to be transmitted, and transmits the phase-rotated signal using the time/frequency resource that is allocated. The time/frequency resource may be a time resource (for example, a subframe, a slot, a symbol, etc.) and/or a frequency resource (for example, a carrier frequency, a channel band, a CC (Component Carrier), a PRB, etc.).

<FIG> provide diagrams to show examples of transmission signal generation processes for sequence-based PUCCHs. In these transmission signal generation processes, phase rotations (cyclic shifts) are applied to base sequences X<NUM> to XM-<NUM> of sequence length M, based on selected amounts of phase rotation α, and the phase-rotated base sequences are input to a CP-OFDM (Cyclic Prefix-Orthogonal Frequency Division Multiplexing) transmitter or a DFT-S-OFDM (Discrete Fourier Transform-Spread-Orthogonal Frequency Division Multiplexing) transmitter. The UE transmits output signals from the CP-OFDM transmitter or the DFT-S-OFDM transmitter.

When amounts of phase rotation α<NUM> to α<NUM> in the CS candidate set are associated with UCI candidates <NUM> to <NUM>, respectively, and value <NUM> is reported as UCI, as shown in <FIG>, the UE applies phase rotations to base sequences X<NUM> to XM-<NUM>, using amount of phase rotation α<NUM>, which is associated with value <NUM>. Similarly, when the UE reports values <NUM> to <NUM> as UCI, as shown in <FIG>, the UE applies phase rotations to base sequences X<NUM> to XM-<NUM> by using amounts of phase rotation α<NUM>, α<NUM> and α<NUM>, which are associated with values <NUM> to <NUM>, respectively.

Next, the decoding of UCI that is reported in a sequence-based PUCCH will be described. Here, although the receipt detection operation to be carried out when UCI is reported by selecting the amount of phase rotation will be described below, the same operation will hold even when UCI is reported by selecting different types of resources (for example, base sequences, time/frequency resources, etc.) or combinations of multiple types of resources.

The NW may detect UCI from a received signal by using maximum likelihood detection (which may be referred to as "MLD" or "correlation detection"). To be more specific, the network may generate replicas of all amounts of phase rotation (phase rotation amount replicas) assigned to the user terminal (for example, the network may generate four patterns of phase rotation amount replicas if the length of the UCI payload is two bits), and generate transmission signal waveforms, as the user terminal does, based on the base sequences and the phase rotation amount replicas. Also, the network may calculate the correlation between the transmission signal waveforms produced thus, and the waveform of the received signal from the user terminal, for all the phase rotation amount replicas, and assume that the phase rotation amount replica to show the highest correlation has been transmitted.

To be more specific, the network may multiply each element of received signal sequences of size M after the DFT (M complex-number sequences) by complex conjugates of transmission signal sequences (M complex-number sequences), which are given by applying phase rotation to the base sequence of the transmission signal based on phase rotation amount replicas, and assume that the phase rotation amount replica, where the absolute value (or the square of the absolute values) of the sum of the M sequences acquired is the largest, has been sent.

Alternatively, the network may generate transmission signal replicas to match the maximum number of amounts of phase rotation that can be assigned (twelve for one PRB), and estimate the amount of phase rotation to yield the highest correlation with the received signal, based on the same operation as the MLD-based operation described above. If the estimated amount of phase rotation is different from the ones assigned, the network may assume that the amount of phase rotation that is closest to the estimated amount of phase rotation, among the assigned amounts of phase rotation, has been transmitted.

Also, a study is underway to report an HARQ-ACK and an SR, up to two bits, in a sequence-based PUCCH. In this case, a number of resources, which are associated with a number of candidates of UCI to be reported in the sequence-based PUCCH, need to be configured from the NW to UE, the problem lies in how to configure the resources. So the present inventors have worked on a method for configuring resources for a sequence-based PUCCH that reports an HARQ-ACK and an SR, and arrived at the present invention.

Hereinafter, transmission (reporting) of UCI may be read as transmission of sequence-based PUCCH.

Now, embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Note that the radio communication methods according to these embodiments may be applied individually or may be applied in combination.

With a first embodiment of the present invention, a method of configuring a PUCCH resource for a sequence-based PUCCH and a method of configuring the PUCCH resource in UE will be described.

The PUCCH resource may refer to at least one of a time resource, a frequency resource and a code resource.

The time resource may be at least one symbol. The time resource may be represented by a slot index, a mini-slot index, and a symbol index within a slot or a mini-slot.

The frequency resource may be represented by, for example, a PRB index in the allocated UL BWP (Bandwidth Part, partial bandwidth, etc.). The frequency resource may be at least one PRB. If the frequency resource is greater than one PRB, the frequency resource may be specified by the first PRB index and the number of PRBs, or may be specified by the first PRB index and the last PRB index.

Envisaging future radio communication systems (for example, NR, <NUM> or <NUM> +), studies are in progress to assign a carrier (component carriers (CCs)) or a system band over a wider bandwidth (for example <NUM> to <NUM>) than in existing LTE systems (for example, LTE Rel. <NUM> to <NUM>). In addition, research is underway to configure one or more frequency bands within this carrier in a user terminal semi-statically. Each frequency band within a carrier is also referred to as a "BWP. " A BWP for UL may be referred to as a "UL BWP.

The code resource may be a CS and/or a base sequence. The code resource may be specified by at least one of a CS index and a sequence index to specify a base sequence. Multiple UEs' sequence-based PUCCHs can be code-division-multiplexed (CDM) by allocating different code resources to different UEs, so that the spectral efficiency can be improved.

The indices, numbers, indicators and so on that specify resources are interchangeable.

The number of CS indices that can be used for a sequence-based PUCCH may be limited. That is, fewer than twelve CSs may be assigned to UE for a sequence-based PUCCH of one PRB.

As for the method of configuring PUCCH resources, the following first configuration method or second configuration method may be used.

In the first configuration method, where there are a number of UCI candidates, the NW signals PUCCH resources that are associated with at least one specific UCI candidate, to UE, and the UE selects PUCCH resources that are associated with another UCI candidate, among the multiple UCI candidates, based on the PUCCH resources associated with the specific UCI candidate. For example, the UE may, using an index that specifies a particular type of PUCCH resource for a particular UCI candidate, and a preconfigured algorithm, selects an index that specifies a particular type of PUCCH resource for another UCI candidate.

The UCI includes HARQ-ACK information and/or SR information.

The HARQ-ACK information, which is one bit, represents <NUM> (NACK) or <NUM> (ACK). The one-bit HARQ-ACK information represents one of <NUM> (NACK-NACK), <NUM> (NACK-ACK), <NUM> (ACK-ACK), and <NUM> (ACK-NACK).

The SR information specifies between a positive SR and a negative SR. UCI that includes no SR information points to a non-SR transmission timing (non-SR). UCI that includes a positive SR may indicate that an SR is present at an SR transmission timing, and may be referred to as "SR-including UCI. " UCI that includes a negative SR indicates that there is no SR at an SR transmission timing. UCI that includes no SR information indicates that no SR transmission timing is provided then. UCI that includes negative SRs and UCI that includes no SR information may be referred to as "UCI including no SR.

A specific UCI candidate may be a specific value of HARQ-ACK information or a specific value of SR information, may be UCI to include a specific value of SR information and a specific value of HARQ-ACK information. When the HARQ-ACK information is one bit, the specific value may be <NUM> (NACK). When the HARQ-ACK information is two bits, the specific value may be <NUM> (NACK-NACK).

Of PUCCH resources, CS candidates that are provided at equal intervals may constitute a CS candidate set. For example, as shown in <FIG>, amounts of phase rotation, which correspond to CS candidates, may be provided at intervals of 2π/the number of CS candidates in the CS candidate set (the number of candidates for HARQ-ACK information).

By using this CS candidate set, the phase of a specific RE stays constant irrespective of UCI (HARQ-ACK information). The NW can perform channel estimation using the signal of the specific RE. That is, the NW can use the specific RE's signal as the DMRS (Demodulation Reference Signal). The NW may demodulate UCI based on the result of channel estimation. By using this set of CS candidates, it is possible to configure the receiver flexibly in the NW.

For example, the NW may demodulate UCI based on MLD, which has been mentioned earlier, or demodulate UCI based on the result of channel estimation using the DMRS of a specific RE, or demodulate UCI by combining these. In addition, the NW may estimate the variance of noise using a specific RE.

Also, by using a set of evenly-spaced CS candidates, the UE can readily determine CS candidates for other UCI candidates from CS candidates for a specific UCI candidate. For example, the UE can determine other CS indices by adding the intervals between CS indices, one by one, to the CS index for a particular UCI candidate.

According to the second configuration method, the NW signals a number of PUCCH resources, which are associated with a number of UCI candidates, respectively.

In each configuration method, resources may be signaled through higher layer signaling (for example, RRC signaling and/or broadcast information) and/or physical layer signaling (for example, DCI (downlink control information)).

Each configuration method may configure PUCCH resources of all types (for example, time resources, frequency resources, code resources, etc.). In addition, in each configuration method, only some types of PUCCH resources may be configured, and other types of PUCCH resources may be configured separately. Other types of PUCCH resource may be common among cells. In this case, the NW may configure PUCCH resources in UEs in a cell by using cell-common information (for example, broadcast information).

According to the first configuration method, the NW signals only PUCCH resources that are associated with part of multiple UCI candidates, to UEs, so that the overhead of signaling can be reduced, compared to the second configuration method.

According to the second configuration method, the NW signals a number of PUCCH resources, which are associated with a number of UCI candidates, respectively, to UEs, so that the NW can configure PUCCH resources flexibly.

According to a second embodiment of the present invention, the NW signals the PUCCH resource for UCI that includes a positive SR and the PUCCH resource for a UCI that includes a negative SR, to UEs.

The NW may signal PUCCH resource configuration information, which designates a number of PUCCH resources, through higher layer signaling, and signal or specify the PUCCH resources in the PUCCH resource configuration information through physical layer signaling. According to this signaling method, the overhead associated with signaling of PUCCH resources can be reduced, so that PUCCH resources can be changed dynamically.

In the PUCCH resource configuration information, the PUCCH resources may be specified by using at least one of PRB indices, symbol indices, sequence indices and CS indices. When the PUCCH resource configuration information specifies some types among multiple types of PUCCH resources, the NW may signal resource information that designates types of resources that are not included in the PUCCH resource configuration information, to UE, through higher layer signaling (for example, RRC signaling and/or broadcast information).

The resource information may be cell-common. In this case, the NW may signal part of the PUCCH resources to UEs in a cell by using information that is common in the cell (for example, broadcast information). For example, the resource information may be information other than CS indices. By configuring CS indices in a UE-specific manner and configuring other PUCCH resources in a cell-common way, it is possible to multiplex UEs in the same time resource and frequency resource.

Since resource information that is common to a number of UEs is used, it is possible to reduce the volume of PUCCH resources, and reduce the overhead pertaining to signaling of PUCCH resources.

The NW may determine different SR transmission timings for each UE, and signal information that indicates the SR transmission timings, via higher layer signaling. This information to specify SR transmission timings may contain the periodicity of SRs, SR offsets (offsets of time resources such as subframes, slots and so on) and so on. At periodic SR transmission timings, the UE transmits a UCI that includes a positive SR or a negative SR, to the NW. At periodic SR transmission timings, the UE transmits UCI including SR information (a positive SR or a negative SR), to the NW.

If a timing that is an SR transmission timing and is also an HARQ-ACK transmission timing arrives, the UE reports UCI that includes SR information and HARQ-ACK information, to the NW.

If a timing that is an SR transmission but not an HARQ-ACK transmission timing arrives, the UE reports UCI that includes SR information but does not include HARQ-ACK information ("SR-only," which is UCI that includes SR information alone), to the NW.

If a timing that is not an SR transmission timing but is an HARQ-ACK transmission timing arrives, the UE may report UCI that includes a negative SR, to the NW. In other words, UCI that does not include SR information ("no-SR," which is UCI to include HARQ-ACK information alone, UCI to specify a non-SR transmission timing, and so on) and UCI that includes a negative SR may use the same PUCCH resources. This method of reporting SRs will be hereinafter referred to as the "first SR reporting method.

At a timing that is not an SR transmission timing but is an HARQ-ACK transmission timing, the UE may report UCI not including SR information to the NW. In other words, the PUCCH resources for UCI that does not include SR information may be different from the PUCCH resources for UCI that includes negative SRs. This method of reporting SRs will be hereinafter referred to as the "second SR reporting method.

A case will be described below, in which UCI not including SR information and UCI that includes a negative SR use the same PUCCH resources. In other words, UCI that includes negative SRs and UCI that includes no SR information are not distinguished, and both are treated as UCI including no SR.

The NW may configure PUCCH resources in UEs according to the first SR reporting method and the first configuration method.

<FIG> is a diagram to show examples of PUCCH resource configuration information for use in the first SR reporting method and the first configuration method, according to the second embodiment.

The NW may specify one PUCCH resource set in the PUCCH resource configuration information, by using a signaling field provided in DCI. The signaling field is a bit sequence of a given length. For the signaling field, TPC (Transmission Power Control) may be used, or ARI (ACK/NACK Resource Indicator) may be used. Although a case will be described below in which the length of the signaling field is two bits, the signaling field's length needs not be two bits.

The PUCCH resource configuration information specifies a number of PUCCH resources that are associated with a number of signaling field values, respectively.

If the signaling field is a TPC command, since no TPC command corresponds to UCI that includes SR information alone, the PUCCH resource configuration information does not have to specify the PUCCH resource for this UCI carrying SR information alone. The NW may signal this PUCCH resource to the UE using UE-specific information (for example, higher layer signaling).

The PUCCH resource configuration information in this drawing specifies, for each signaling field value, the PUCCH resource for UCI that includes a specific value of HARQ-ACK information and a positive SR, and the PUCCH resource for UCI that includes a specific value of HARQ-ACK information and a negative SR.

When the HARQ-ACK information is one bit, the specific value of HARQ-ACK information may be <NUM> (NACK). When the HARQ-ACK information is two bits, the specific value of HARQ-ACK information may be <NUM> (NACK-NACK).

The NW may configure PUCCH resources in UEs according to the first SR reporting method and the second configuration method.

<FIG> is a diagram to show examples of PUCCH resource configuration information for use in the first SR reporting method and the second configuration method when the HARQ-ACK information is one bit, according to the second embodiment.

The PUCCH resource configuration information in this drawing specifies, for each signaling field value, the PUCCH resources for UCI that includes candidates for HARQ-ACK information (<NUM> and <NUM>) and a positive SR, the PUCCH resources for UCI that includes candidates for a number of pieces of HARQ-ACK information (<NUM> and <NUM>) and a negative SR.

<FIG> is a diagram to show examples of PUCCH resource configuration information for use in the first SR reporting method and the second configuration method when the HARQ-ACK information is two bits, according to the second embodiment.

The PUCCH resource configuration information in this drawing specifies, for each signaling field value, the PUCCH resources for UCI that includes candidates for HARQ-ACK information (<NUM>, <NUM>, <NUM> and <NUM>) and a positive SR, and the PUCCH resources for UCI that includes candidates for HARQ-ACK information (<NUM>, <NUM>, <NUM> and <NUM>) and a negative SR.

According to the first SR reporting method, the NW signals the PUCCH resources for UCI that includes positive SRs and the PUCCH resourced for UCI that includes negative SRs to UEs, so that the NW can configure PUCCH resources flexibly.

Also, since the PUCCH resources for UCI not including SR information are the same as the PUCCH resources for UCI that includes negative SRs, the overhead related to signaling of PUCCH resources can be reduced, so that it is possible to reduce the volume of PUCCH resources.

A case will be described below, in which UCI that does not include SR information and UCI that includes negative SRs use different PUCCH resources. In other words, UCI that includes negative SRs and UCI that includes no SR information are distinguished.

The NW and UEs can use the second SR reporting method and the first configuration method.

<FIG> is a diagram to show examples of PUCCH resource configuration information for use in the second SR reporting method and the first configuration method, according to the second embodiment.

The PUCCH resource configuration information in this drawing specifies, for each signaling field value, the PUCCH resource for UCI that includes a specific value of HARQ-ACK information and a positive SR, the PUCCH resource for UCI that includes a specific value of HARQ-ACK information and a negative SR, and the PUCCH resource for UCI that includes a specific value of HARQ-ACK information but does not include SR information.

The NW and the UE can use the second SR reporting method and the second configuration method.

<FIG> is a diagram to show examples of PUCCH resource configuration information for use in the second SR reporting method and the second configuration method when the HARQ-ACK information is one bit, according to the second embodiment.

The PUCCH resource configuration information in this drawing specifies, for each signaling field value, the PUCCH resources for UCI that includes candidates for HARQ-ACK information (<NUM> and <NUM>) and a positive SR, the PUCCH resources for UCI that includes candidates for HARQ-ACK information (<NUM> and <NUM>) and a negative SR, and the PUCCH resources for UCI that includes candidates for HARQ-ACK information (<NUM> and <NUM>) but does not include SR information.

<FIG> is a diagram to show examples of PUCCH resource configuration information for use in the second SR reporting method and the second configuration method when the HARQ-ACK information is two bits, according to the second embodiment.

The PUCCH resource configuration information in this drawing specifies, for each signaling field value, the PUCCH resources for UCI that includes candidates for HARQ-ACK information (<NUM>, <NUM>, <NUM> and <NUM>) and a positive SR, the PUCCH resources for UCI that includes candidates for HARQ-ACK information (<NUM>, <NUM>, <NUM> and <NUM>) and a negative SR, and the PUCCH resources for UCI that includes candidates for HARQ-ACK information (<NUM>, <NUM>, <NUM> and <NUM>) but does not include SR information.

Specific examples of the first SR reporting method and the second SR reporting method will be described now.

Here, assumed that the HARQ-ACK information is two bits. Also, a case will be shown here where sequence-based PUCCHs for UE #<NUM> and UE #<NUM> are code-division-multiplexed (CDM) in the same time resource and frequency resource. So, the NW assigns different CS candidate sets to UE #<NUM> and UE #<NUM>. Note that the NW may assign different base sequences to UE #<NUM> and UE #<NUM>.

<FIG> provide diagrams to show examples of CS candidate sets assigned to each UE in the first SR reporting method.

As shown in <FIG>, for UE #<NUM>, CS indices <NUM>, <NUM>, <NUM> and <NUM> are assigned to UCI that includes a negative SR and HARQ-ACK information, and CS indices <NUM>, <NUM>, <NUM> and <NUM> are assigned to UCI that includes a positive SR and HARQ-ACK information.

The CSI indices for UCI not including SR information are the same as the CSI indices for UCI that includes a negative SR and the HARQ-ACK information.

Here, the CS indices of UE #<NUM> and the CS indices of UE #<NUM> may overlap. For example, as shown in <FIG>, the CS indices of UE#<NUM> for UCI that includes a positive SR, and the CS indices of UE #<NUM> for UCI that includes a negative SR or UCI that includes no SR information, overlap.

<FIG> provide diagrams to show examples of CS candidate sets and frequency resources for UCI that includes an SR alone.

As shown in <FIG>, where there are UEs #<NUM> to #<NUM>, CS indices <NUM> to <NUM> are assigned to UCI that include an SR alone. As shown in <FIG>, where there are UEs #<NUM> to #<NUM>, one PRB is allocated, as a frequency resource, to UCI that includes HARQ-ACK information, and another PRB in the same symbol is allocated to UCI that includes an SR alone. That is, UE #<NUM> and UE #<NUM> use the same time and frequency resources to transmit UCI that includes HARQ-ACK information. Also, since UCI that includes HARQ-ACK information and UCI that does not include HARQ-ACK information use different frequency resources, the same set of CS candidates (code resources) may be assigned.

Note that one PRB may be allocated to UCI that only includes an SR, and two or more PRBs may be allocated to UCI that includes HARQ-ACK information.

<FIG> is a diagram to show examples of timings for transmitting UCI when the first SR reporting method is used.

The NW configures the same SR periodicity and different SR offsets for UE #<NUM> and UE #<NUM>. The SR periodicity in the example in this drawing is <NUM>.

When an SR transmission timing is also a timing to transmit an HARQ-ACK, each UE transmits UCI that includes SR information and HARQ-ACK information (SR+HARQ-ACK). In the event an SR transmission timing is not a timing to transmit an HARQ-ACK, each UE transmits UCI that includes SR information alone (SR only).

When an HARQ-ACK transmission timing arrives during a period in which there is no SR transmission timing (non-SR period), each UE transmits UCI that does not include SR information but does include HARQ-ACK information (HARQ-ACK (non-SR)).

At time t0, when UE #<NUM> transmits UCI that includes a positive SR and HARQ-ACK information, and UE #<NUM> transmits UCI including no SR information, as shown in <FIG>, the CS indices assigned to the UCI of UE #<NUM> that includes a positive SR and HARQ-ACK information and the CS indices assigned to the UCI of UE #<NUM> that does not include SR information are the same, so these UCIs conflict.

<FIG> provide diagrams to show examples of CS candidate sets assigned to each UE in the first SR reporting method and the second SR reporting method. UE #<NUM> is assigned CS indices in accordance with the first SR reporting method. UE #<NUM> is assigned CS indices in accordance with the second SR reporting method.

As shown in <FIG>, for UE #<NUM>, as in <FIG>, CS indices <NUM>, <NUM>, <NUM> and <NUM> are assigned to UCI that includes a negative SR and HARQ-ACK information, and CS indices <NUM>, <NUM>, <NUM> and <NUM> are assigned to UCI that includes a positive SR and HARQ-ACK information.

As shown in <FIG>, for UE #<NUM>, CS indices <NUM>, <NUM>, <NUM> and <NUM> are assigned to UCI that includes a negative SR and HARQ-ACK information, and CS indices <NUM>, <NUM>, <NUM> and <NUM> are assigned to UCI that includes a positive SR and HARQ-ACK information. Note that, for UE #<NUM>, CS indices <NUM>, <NUM>, <NUM> and <NUM> may be assigned to UCI that includes a positive SR and HARQ-ACK information, and CS indices <NUM>, <NUM>, <NUM> and <NUM> may be assigned to UCI that includes a negative SR and HARQ-ACK information.

As shown in <FIG>, for UE #<NUM>, furthermore, CS indices <NUM>, <NUM>, <NUM> and <NUM> are assigned to UCI that includes no SR information but include HARQ-ACK information.

In UE #<NUM>, different CS indices are assigned between UCI that includes negative SRs and UCI that includes no SR information. Also, the same CS indices are assigned to UCI that includes positive SRs and UCI that includes no SR information.

The CS indices for UCI that includes SRs alone and the frequency resources for the sequence-based PUCCHs are the same as in <FIG>.

<FIG> is a diagram to show examples of timings for transmitting UCI when the first SR reporting method and the second SR reporting method are used.

At time t0, when UE #<NUM> transmits UCI that includes a positive SR and HARQ-ACK information, and UE #<NUM> transmits UCI that does not include SR information, as shown in <FIG>, the CS indices assigned to the UCI of UE #<NUM> that includes SR information and HARQ-ACK information, and the CS indices assigned to the UCI of UE #<NUM> that does not include SR information are different, so that these UCIs do not collide with each other.

According to the second SR reporting method, the NW signals the PUCCH resources for UCI that includes negative SRs and the PUCCH resources for UCI that does not include SR information, separately, so that, even when a number of UEs transmit UCI that includes SR information and HARQ-ACK information and UCI that includes no SR information by using the same time resource and frequency resource, collisions between CS indices can be prevented.

According to the second embodiment described above, the NW can configure the PUCCH resources associated with UCI that includes positive SRs and the PUCCH resources associated with UCI that includes negative SRs, flexibly.

According to a third embodiment of the present invention, the NW signals the PUCCH resource that is associated with UCI candidates that include one value of SR information (a positive SR or a negative SR), to UE, and, based on the PUCCH resource signaled, the UE selects the PUCCH resource that is associated with UCI candidates that include the other value of SR information.

Here, the NW signals the PUCCH resource for UCI that includes a negative SR, to UE, and, based on the PUCCH resource that is signaled, the UE selects the PUCCH resource for UCI that includes a positive SR. Note that the NW signals the PUCCH resource for UCI that includes a positive SR, to the UE, and, based on the PUCCH resource that is signaled, the UE may select the PUCCH resource for UCI that includes a negative SR.

The NW may configure the PUCCH resources in the UE in accordance with the first SR reporting method and the first configuration method.

<FIG> is a diagram to show examples of PUCCH resource configuration information for use in the first SR reporting method and the first configuration method, according to the third embodiment.

The PUCCH resource configuration information in this drawing specifies the PUCCH resource for UCI that includes a specific value of HARQ-ACK information and a negative SR, for each signaling field value.

The UE, using the PUCCH resource for UCI that includes a negative SR and a given algorithm, may select the PUCCH resource for UCI that includes a positive SR. The UE may select a CS index of UCI that includes a positive SR by adding a given offset to a CS index of UCI that includes a negative SR. For example, if n is a CS index for UCI that includes a negative SR and y is an integer that is defined or configured in advance, then, (n+y mod the number of CS indices) gives a CS index of UCI that includes a positive SR. Also, the UE may select a PRB index of UCI that includes a positive SR, by adding a given offset to a PRB index of UCI that includes a negative SR. For example, if n is a PRB index of UCI that includes a negative SR and z is an integer that is defined or configured in advance, then, (n+z mod the number of PRB indices) gives a PRB index of UCI that includes a positive SR. Here, the number of CS/PRB indices may be the number of CS/PRB indices limited by signals/commands from the NW. y and z may be positive or negative.

For PUCCH resources other than CS indices (for example, PRB indices, symbol indices, sequence indices, etc.), the PUCCH resources for UCI that includes positive SRs may be the same as the PUCCH resources for UCI that includes negative SRs.

The NW may configure the PUCCH resources in UEs in accordance with the first SR reporting method and the second configuration method.

<FIG> is a diagram to show examples of PUCCH resource configuration information for use in the first SR reporting method and the second configuration method when the HARQ-ACK information is one bit, according to the third embodiment.

The PUCCH resource configuration information in this drawing specifies the PUCCH resources for UCI that includes candidates for HARQ-ACK information (<NUM> and <NUM>) and a negative SR, for each signaling field value.

<FIG> is a diagram to show examples of PUCCH resource configuration information for use in the first SR reporting method and the second configuration method when the HARQ-ACK information is two bits, according to the third embodiment.

The PUCCH resource configuration information in this drawing specifies the PUCCH resources for UCI that includes candidates for HARQ-ACK information (<NUM>, <NUM>, <NUM> and <NUM>) and a negative SR, for each signaling field value.

According to the third embodiment described above, the NW signals the PUCCH resources for UCI that includes one of a negative SR and a positive SR to UEs, and does not signal the PUCCH resources for UCI that include the other one to UEs, so that the overhead associated with signaling can be reduced.

Now, the structure of the radio communication system according to one embodiment of the present invention will be described below. In this radio communication system, communication is performed using one or a combination of the radio communication methods according to the herein-contained embodiments of the present invention.

<FIG> is a diagram to show an example of a schematic structure of a radio communication system according to one embodiment of the present invention. A radio communication system <NUM> can adopt carrier aggregation (CA) and/or dual connectivity (DC) to group a number of fundamental frequency blocks (component carriers) into one, where the LTE system bandwidth (for example, <NUM>) constitutes one unit.

Note that the radio communication system <NUM> may be referred to as "LTE (Long Term Evolution)," "LTE-A (LTE-Advanced)," "LTE-B (LTE-Beyond)," "SUPER <NUM>," "IMT-Advanced," "<NUM> (4th generation mobile communication system)," "<NUM> (5th generation mobile communication system)," "NR (New Radio)," "FRA (Future Radio Access)," "New-RAT (Radio Access Technology)," and so on, or may be seen as a system to implement these.

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

The user terminals <NUM> can connect with both the radio base station <NUM> and the radio base stations <NUM>. The user terminals <NUM> may use the macro cell C1 and the small cells C2 at the same time by means of CA or DC. Furthermore, the user terminals <NUM> may apply CA or DC using a number of cells (CCs) (for example, five or fewer CCs or six or more CCs).

A structure may be employed here in which wire connection (for example, optical fiber, which is compliance with the CPRI (Common Public Radio Interface), the X2 interface, and so on) or wireless connection is established between the radio base station <NUM> and the radio base station <NUM> (or between two radio base stations <NUM>).

OFDMA is a multi-carrier communication scheme to perform communication by dividing a frequency bandwidth into a number of narrow frequency bandwidths (subcarriers) and mapping data to each subcarrier. SC-FDMA is a single-carrier communication scheme to mitigate interference between terminals by dividing the system bandwidth into bands formed with one or continuous resource blocks per terminal, and allowing a number of terminals to use mutually different bands. Note that the radio access schemes for the uplink and the downlink are not limited to this combination, and other radio access schemes may be used as well.

In the radio communication system <NUM>, a downlink shared channel (PDSCH (Physical Downlink Shared CHannel)), which is used by each user terminal <NUM> on a shared basis, a broadcast channel (PBCH (Physical Broadcast CHannel)), downlink L1/L2 control channels and so on are used as downlink channels. User data, higher layer control information and SIBs (System Information Blocks) are communicated in the PDSCH. Also, the MIB (Master Information Block) is communicated in the PBCH.

The downlink L1/L2 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. Downlink control information (DCI), including PDSCH and/or PUSCH scheduling information, is communicated by the PDCCH.

Note that scheduling information may be signaled via DCI. For example, DCI to schedule receipt of DL data may be referred to as "DL assignment," and DCI to schedule transmission of UL data may be referred to as "UL grant.

The number of OFDM symbols to use for the PDCCH is communicated by the PCFICH. HARQ (Hybrid Automatic Repeat reQuest) delivery acknowledgment information (also referred to as, for example, "retransmission control information," "HARQ-ACK," "ACK/NACK," 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.

In the radio communication system <NUM>, an uplink shared channel (PUSCH (Physical Uplink Shared CHannel)), which is used by each user terminal <NUM> 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, higher layer control information and so on are communicated by the PUSCH. Also, in the PUCCH, downlink radio quality information (CQI (Channel Quality Indicator)), delivery acknowledgment information, scheduling requests (SRs) and so on are communicated. By means of the PRACH, random access preambles for establishing connections with cells are communicated.

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

<FIG> is a diagram to show an example of an overall structure of a radio base station according to one embodiment of the present invention. A radio base station <NUM> has a number of transmitting/receiving antennas <NUM>, amplifying sections <NUM>, transmitting/receiving sections <NUM>, a baseband signal processing section <NUM>, a call processing section <NUM> and a communication path interface <NUM>. Note that one or more transmitting/receiving antennas <NUM>, amplifying sections <NUM> and transmitting/receiving sections <NUM> may be provided.

In the baseband signal processing section <NUM>, the user data is subjected to transmission processes, including a PDCP (Packet Data Convergence Protocol) layer process, user data division and coupling, RLC (Radio Link Control) layer transmission processes such as RLC retransmission control, MAC (Medium Access Control) retransmission control (for example, an 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 transmitting/receiving section <NUM>. Furthermore, downlink control signals are also subjected to transmission processes such as channel coding and an inverse fast Fourier transform, and forwarded to each transmitting/receiving section <NUM>.

Baseband signals that are precoded and output from the baseband signal processing section <NUM> on a per antenna basis are converted into a radio frequency band in the transmitting/receiving sections <NUM>, and then transmitted. The radio frequency signals having been subjected to frequency conversion in the transmitting/receiving sections <NUM> are amplified in the amplifying sections <NUM>, and transmitted from the transmitting/receiving antennas <NUM>. The transmitting/receiving sections <NUM> can be constituted by transmitters/receivers, transmitting/receiving circuits or transmitting/receiving apparatus that can be described based on general understanding of the technical field to which the present invention pertains. Note that a transmitting/receiving section <NUM> may be structured as a transmitting/receiving section in one entity, or may be constituted by a transmitting section and a receiving section.

In the baseband signal processing section <NUM>, user data that is included in the uplink signals that are input is subjected to a fast Fourier transform (FFT) process, an inverse discrete Fourier transform (IDFT) process, error correction decoding, a MAC retransmission control receiving process, and RLC layer and PDCP layer receiving processes, and forwarded to the higher station apparatus <NUM> via the communication path interface <NUM>. The call processing section <NUM> performs call processing (such as setting up and releasing communication channels), manages the state of the radio base stations <NUM> and manages the radio resources.

The communication path interface section <NUM> transmits and receives signals to and from the higher station apparatus <NUM> via a given interface. Also, the communication path interface <NUM> may transmit and receive signals (backhaul signaling) with other radio base stations <NUM> via an inter-base station interface (which is, for example, optical fiber that is in compliance with the CPRI (Common Public Radio Interface), the X2 interface, etc.).

Also, the transmitting/receiving sections <NUM> may receive sequences (for example, sequence-based PUCCHs) that are associated with uplink control information (UCI).

Also, the transmitting/receiving sections <NUM> may transmit parameters for sequence-based PUCCHs to the user terminal <NUM>.

<FIG> is a diagram to show an example of a functional structure of a radio base station according to one embodiment of the present invention. Note that, although this example primarily shows functional blocks that pertain to characteristic parts of the present embodiment, the radio base station <NUM> has other functional blocks that are necessary for radio communication as well.

The baseband signal processing section <NUM> has a control section (scheduler) <NUM>, a transmission signal generation section <NUM>, a mapping section <NUM>, a received signal processing section <NUM> and a measurement section <NUM>. Note that these configurations have only to be included in the radio base station <NUM>, and some or all of these configurations may not be included in the baseband signal processing section <NUM>.

The control section <NUM>, for example, controls the generation of signals in the transmission signal generation section <NUM>, the allocation of signals by the mapping section <NUM>, and so on. Furthermore, the control section <NUM> controls the signal receiving processes in the received signal processing section <NUM>, the measurements of signals in the measurement section <NUM>, and so on.

The control section <NUM> controls the scheduling (for example, resource allocation) of system information, downlink data signals (for example, signals transmitted in the PDSCH) and downlink control signals (for example, signals transmitted in the PDCCH and/or the EPDCCH, such as delivery acknowledgement information). The control section <NUM> 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 necessary for uplink data signals, and so on. Also, the control section <NUM> controls the scheduling of synchronization signals (for example, the PSS (Primary Synchronization Signal)/SSS (Secondary Synchronization Signal)), downlink reference signals (for example, the CRS, the CSI-RS, the DM-RS, etc.) and so on.

The control section <NUM> also controls the scheduling of uplink data signals (for example, signals transmitted in the PUSCH), uplink control signals (for example, signals transmitted in the PUCCH and/or the PUSCH, such as delivery acknowledgment information), random access preambles (for example, signals transmitted in the PRACH), uplink reference signals, and/or other signals.

The transmission signal generation section <NUM> generates downlink signals (downlink control signals, downlink data signals, downlink reference signals and so on) based on commands from the control section <NUM>, and outputs these signals to the mapping section <NUM>. The transmission signal generation section <NUM> can be constituted by a signal generator, a signal generating circuit or signal generating apparatus that can be described based on general understanding of the technical field to which the present invention pertains.

For example, the transmission signal generation section <NUM> generates DL assignments, which signal downlink data allocation information, and/or UL grants, which signal uplink data allocation information, based on commands from the control section <NUM>. DL assignments and UL grants are both DCI, and follow the DCI format. Also, the downlink data signals are subjected to the coding process, the modulation process and so on, by using coding rates and modulation schemes that are determined based on, for example, channel state information (CSI) from each user terminal <NUM>.

The mapping section <NUM> maps the downlink signals generated in the transmission signal generation section <NUM> to given radio resources based on commands from the control section <NUM>, and outputs these to the transmitting/receiving sections <NUM>. The mapping section <NUM> can be constituted by a mapper, a mapping circuit or mapping apparatus that can be described based on general understanding of the technical field to which the present invention pertains.

The received signal processing section <NUM> performs receiving processes (for example, demapping, demodulation, decoding and so on) of received signals that are input from the transmitting/receiving sections <NUM>. Here, the received signals include, for example, uplink signals transmitted from the user terminal <NUM> (uplink control signals, uplink data signals, uplink reference signals, etc.). For the received signal processing section <NUM>, a signal processor, a signal processing circuit or signal processing apparatus that can be described based on general understanding of the technical field to which the present invention pertains can be used.

The received signal processing section <NUM> outputs the decoded information, acquired through the receiving processes, to the control section <NUM>. For example, when a PUCCH to contain an HARQ-ACK is received, the received signal processing section <NUM> outputs this HARQ-ACK to the control section <NUM>. Also, the received signal processing section <NUM> outputs the received signals and/or the signals after the receiving processes to the measurement section <NUM>.

For example, the measurement section <NUM> may perform RRM (Radio Resource Management) measurements, CSI (Channel State Information) measurements and so on, based on the received signals. The measurement section <NUM> may measure the received power (for example, RSRP (Reference Signal Received Power)), the received quality (for example, RSRQ (Reference Signal Received Quality), SINR (Signal to Interference plus Noise Ratio), etc.), the signal strength (for example, RSSI (Received Signal Strength Indicator)), transmission path information (for example, CSI), and so on. The measurement results may be output to the control section <NUM>.

Also, the control section <NUM> may allocate the radio resources for sequence-based PUCCHs, to user terminals <NUM>. Also, the control section <NUM> may allocate base sequences, CSs (CS candidate sets) and so on for sequence-based PUCCHs, to user terminals <NUM>.

<FIG> is a diagram to show an example of an overall structure of a user terminal according to one embodiment of the present invention. A user terminal <NUM> has a number of transmitting/receiving antennas <NUM>, amplifying sections <NUM>, transmitting/receiving sections <NUM>, a baseband signal processing section <NUM> and an application section <NUM>. Note that one or more transmitting/receiving antennas <NUM>, amplifying sections <NUM> and transmitting/receiving sections <NUM> may be provided.

Radio frequency signals that are received in the transmitting/receiving antennas <NUM> are amplified in the amplifying sections <NUM>. The transmitting/receiving sections <NUM> receive the downlink signals amplified in the amplifying sections <NUM>. The received signals are subjected to frequency conversion and converted into the baseband signal in the transmitting/receiving sections <NUM>, and output to the baseband signal processing section <NUM>. A transmitting/receiving section <NUM> can be constituted by a transmitters/receiver, a transmitting/receiving circuit or transmitting/receiving apparatus that can be described based on general understanding of the technical field to which the present invention pertains. Note that a transmitting/receiving section <NUM> may be structured as a transmitting/receiving section in one entity, or may be constituted by a transmitting section and a receiving section.

The baseband signal processing section <NUM> performs, for the baseband signal that is input, an FFT process, error correction decoding, a retransmission control receiving process and so on. Downlink user data is forwarded to the application section <NUM>. The application section <NUM> performs processes related to higher layers above the physical layer and the MAC layer, and so on. Also, in the downlink data, the broadcast information can be also forwarded to the application section <NUM>.

Meanwhile, uplink user data is input from the application section <NUM> to the baseband signal processing section <NUM>. The baseband signal processing section <NUM> performs a retransmission control transmission process (for example, an HARQ transmission process), channel coding, precoding, a discrete Fourier transform (DFT) process, an IFFT process and so on, and the result is forwarded to the transmitting/receiving sections <NUM>. Baseband signals that are output from the baseband signal processing section <NUM> are converted into a radio frequency band in the transmitting/receiving sections <NUM> and transmitted. The radio frequency signals that are subjected to frequency conversion in the transmitting/receiving sections <NUM> are amplified in the amplifying sections <NUM>, and transmitted from the transmitting/receiving antennas <NUM>.

Also, the transmitting/receiving sections <NUM> may transmit sequences (for example, sequence-based PUCCHs) that are associated with uplink control information (UCI).

Also, the transmitting/receiving sections <NUM> may receive, from the radio base station <NUM>, parameters that specify the PUCCH resources for sequence-based PUCCHs (for example, at least one of PUCCH resource configuration information, resource information and the signaling field).

<FIG> is a diagram to show an example of a functional structure of a user terminal according to one embodiment of the present invention. Note that, although this example primarily shows functional blocks that pertain to characteristic parts of the present embodiment, the user terminal <NUM> has other functional blocks that are necessary for radio communication as well.

Furthermore, when various kinds of information signaled from the radio base station <NUM> are acquired via the received signal processing section <NUM>, the control section <NUM> may update the parameters to use in control based on these pieces of information.

The transmission signal generation section <NUM> generates uplink signals (uplink control signals, uplink data signals, uplink reference signals, etc.) based on commands from the control section <NUM>, and outputs these signals to the mapping section <NUM>. The transmission signal generation section <NUM> can be constituted by a signal generator, a signal generating circuit or signal generating apparatus that can be described based on general understanding of the technical field to which the present invention pertains.

For example, the transmission signal generation section <NUM> generates uplink control signals related to delivery acknowledgement information, channel state information (CSI) and so on, based on commands from the control section <NUM>. Also, the transmission signal generation section <NUM> generates uplink data signals based on commands from the control section <NUM>. For example, when a UL grant is included in a downlink control signal that is signaled from the radio base station <NUM>, the control section <NUM> commands the transmission signal generation section <NUM> to generate an uplink data signal.

The mapping section <NUM> maps the uplink signals generated in the transmission signal generation section <NUM> to radio resources based on commands from the control section <NUM>, and outputs the result to the transmitting/receiving sections <NUM>. The mapping section <NUM> can be constituted by a mapper, a mapping circuit or mapping apparatus that can be described based on general understanding of the technical field to which the present invention pertains.

The received signal processing section <NUM> performs receiving processes (for example, demapping, demodulation, decoding and so on) of received signals that are input from the transmitting/receiving sections <NUM>. 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 <NUM>. The received signal processing section <NUM> can be constituted by a signal processor, a signal processing circuit or signal processing apparatus that can be described based on general understanding of the technical field to which the present invention pertains. Also, the received signal processing section <NUM> can constitute the receiving section according to the present invention.

The received signal processing section <NUM> outputs the decoded information, acquired through the receiving processes, to the control section <NUM>. The received signal processing section <NUM> outputs, for example, broadcast information, system information, RRC signaling, DCI and so on, to the control section <NUM>. Also, the received signal processing section <NUM> outputs the received signals and/or the signals after the receiving processes to the measurement section <NUM>.

For example, the measurement section <NUM> may perform RRM measurements, CSI measurements and so on based on the received signals. The measurement section <NUM> may measure the received power (for example, RSRP), the received quality (for example, RSRQ, SINR, etc.), the signal strength (for example, RSSI), transmission path information (for example, CSI), and so on. The measurement results may be output to the control section <NUM>.

Furthermore, the control section <NUM> may control the selection of radio resources for use for transmitting a sequence (for example, a sequence-based PUCCH), from among a number of radio resources (for example, PUCCH resources) designated in configuration information (for example, PUCCH resource configuration information) signaled from the radio base station <NUM>, based on radio resources associated with identification information (for example, the signaling field) signaled from the radio base station <NUM>.

Also, the multiple radio resources may each include a cyclic shift and/or a base sequence for the sequence.

Also, the configuration information may be signaled via higher layer signaling. The identification information may be signaled via downlink control information.

The multiple radio resources may each include a radio resource that is associated with uplink control information including a scheduling request, and a radio resource that is associated with uplink control information including no scheduling request (second embodiment).

The multiple radio resources may be each associated with one of uplink control information including a scheduling request and uplink control information not including a scheduling request. Then, based on the radio resource associated with the identification information, the control section <NUM> may select the radio resources associated with the other uplink control information (third embodiment).

Note that the block diagrams that have been used to describe the above embodiments show blocks in functional units. These functional blocks (components) may be implemented in arbitrary combinations of hardware and/or software. Also, the method for implementing each functional block is not particularly limited. That is, each functional block may be realized by one piece of apparatus that is physically and/or logically integrated, or may be realized by directly and/or indirectly connecting two or more physically and/or logically separate pieces of apparatus (via wire or wireless, for example) and using these multiple pieces of apparatus.

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> is a diagram to show an example hardware structure of a radio base station and a user terminal according to one embodiment of the present invention. Physically, the above-described radio base stations <NUM> and user terminals <NUM> may be formed as computer apparatus that includes a processor <NUM>, a memory <NUM>, a storage <NUM>, communication apparatus <NUM>, input apparatus <NUM>, output apparatus <NUM> and a bus <NUM>.

Note that the hardware structure of a radio base station <NUM> and a user terminal <NUM> may be designed to include one or more of each apparatus shown in the drawing, or may be designed not to include part of the apparatus.

For example, although only one processor <NUM> is shown, a number of processors may be provided. Furthermore, processes may be implemented with one processor, or processes may be implemented in sequence, or in different manners, on two or more processors.

Each function of the radio base station <NUM> and the user terminal <NUM> is implemented by reading given software (program) on hardware such as the processor <NUM> and the memory <NUM>, and by controlling the calculations in the processor <NUM>, the communication in the communication apparatus <NUM>, and the reading and/or writing of data in the memory <NUM> and the storage <NUM>.

The processor <NUM> may control the whole computer by, for example, running an operating system. The processor <NUM> may be configured with a central processing unit (CPU), which includes interfaces with peripheral apparatus, control apparatus, computing apparatus, registers and so on. For example, the above-described baseband signal processing section <NUM> (<NUM>), call processing section <NUM> and others may be implemented by the processor <NUM>.

Furthermore, the processor <NUM> reads programs (program codes), software modules or data, from the storage <NUM> and/or the communication apparatus <NUM>, into the memory <NUM>, and executes various processes according to these.

The memory <NUM> is a computer-readable recording medium, and may be constituted by, for example, at least one of a ROM (Read Only Memory), an EPROM (Erasable Programmable ROM), an EEPROM (Electrically EPROM), a RAM (Random Access Memory) and/or other appropriate storage media. The memory <NUM> may be referred to as a "register," a "cache," a "main memory (primary storage apparatus)" and so on. The memory <NUM> can store executable programs (program codes), software modules and/and so on for implementing the radio communication methods according to embodiments of the present invention.

The communication apparatus <NUM> is hardware (transmitting/receiving device) for allowing inter-computer communication by 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. The communication apparatus <NUM> may be configured to include a high frequency switch, a duplexer, a filter, a frequency synthesizer and so on in order to realize, for example, frequency division duplex (FDD) and/or time division duplex (TDD). For example, the above-described transmitting/receiving antennas <NUM> (<NUM>), amplifying sections <NUM> (<NUM>), transmitting/receiving sections <NUM> (<NUM>), communication path interface <NUM> and so on may be implemented by the communication apparatus <NUM>.

For example, the processor <NUM> may be implemented using at least one of these pieces of hardware.

Note that the terminology used in this specification and the terminology that is needed to understand this specification may be replaced by other terms that convey 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.

Furthermore, a radio frame may be comprised of one or more periods (frames) in the time domain. Each of 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 (for example, <NUM>) that does not depend on numerology.

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

A radio frame, a subframe, a slot, a minislot and a symbol all represent the time unit in signal communication. A radio frame, a subframe, a slot, a minislot and a symbol may be each called by other applicable names. For example, one subframe may be referred to as a "transmission time interval (TTI)," or a number of consecutive subframes may be referred to as a "TTI," or one slot or minislot may be referred to as a "TTI. " That is, a subframe and/or a TTI may be a subframe (<NUM>) in existing LTE, may be a shorter period than <NUM> (for example, one to thirteen symbols), or may be a longer period of time than <NUM>. Note that the unit to represent the TTI may be referred to as a "slot," a "mini slot" and so on, instead of a "subframe.

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 in each user terminal) to allocate to each user terminal in TTI units.

The TTI may be the transmission time unit of channel-encoded data packets (transport blocks), code blocks and/or codewords, or may be the unit of processing in scheduling, link adaptation and so on. Note that, when a TTI is given, the period of time (for example, the number of symbols) in which transport blocks, code blocks and/or codewords are actually mapped may be shorter than the TTI.

Note that, when one slot or one minislot is referred to as a "TTI," one or more TTIs (that is, one or multiple slots or one or more minislots) may be the minimum time unit of scheduling. Also, the number of slots (the number of minislots) to constitute this minimum time unit of scheduling may be controlled.

A TTI having a time duration of <NUM> may be referred to as a "normal TTI (TTI in LTE Rel. <NUM> to <NUM>)," 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 sub-slot" and so on.

Note that a long TTI (for example, a normal TTI, a subframe, etc.) may be replaced with a TTI having a time duration exceeding <NUM>, and a short TTI (for example, a shortened TTI) may be replaced with a TTI having a TTI duration less than the TTI duration of a long TTI and not less than <NUM>.

A resource block (RB) is the unit of resource allocation in the time domain and the frequency domain, and may include one or a number of consecutive subcarriers in the frequency domain. Also, an RB may include one or more symbols in the time domain, and may be one slot, one minislot, one subframe or one TTI in length. One TTI and one subframe each 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.

For example, one RE may be a radio resource region of one subcarrier and one symbol.

Note that the structures of radio frames, subframes, slots, minislots, symbols and so on described above are merely examples. For example, configurations pertaining to the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or 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 can be variously changed.

Also, the information and parameters described in this specification may be represented in absolute values or in relative values with respect to given values, or may be represented using other applicable information. For example, a radio resource may be specified by a given index.

Information, signals and so on may be input and/or output via a number of network nodes.

The information, signals and so on that are input and/or output may be stored in a specific location (for example, a memory), or may be managed using a management table. The information, signals and so on to be input and/or output can be overwritten, updated or appended. The information, signals and so on that are output may be deleted. The information, signals and so on that are input may be transmitted to other pieces of apparatus.

Signaling of information is by no means limited to the aspects/embodiments described in this specification, and other methods may be used as well. For example, signaling of information may be implemented by using physical layer signaling (for example, downlink control information (DCI), uplink control information (UCI), higher layer signaling (for example, RRC (Radio Resource Control) signaling, 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 of these.

Also, MAC signaling may be signaled using, for example, MAC control elements (MAC CEs (Control Elements)).

Also, signaling of given information (for example, signaling of information to the effect that "X holds") does not necessarily have to be sent explicitly, and can be sent implicitly (for example, by not signaling this piece of information, by signaling another piece of information, and so on).

Decisions may be made in values represented by one bit (<NUM> or <NUM>), may be made in Boolean values that represent true or false, or may be made by comparing numerical values (for example, comparison against a given value).

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 can accommodate one or more (for example, three) cells (also referred to as "sectors"). When a base station accommodates a number of cells, the entire coverage area of the base station can be partitioned into multiple smaller areas, and each smaller area can provide communication services through base station subsystems (for example, indoor small base stations (RRHs (Remote Radio Heads))). 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.

Furthermore, the 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 among a number of user terminals (D2D (Device-to-Device)). In this case, user terminals <NUM> may have the functions of the radio base stations <NUM> described above. In addition, terms such as "uplink" and "downlink" may be interpreted as "side. " For example, an uplink channel may be interpreted as a side channel.

Certain actions which have been described in this specification to be performed by base stations may, in some cases, be performed by its higher nodes (upper nodes). In a network comprised of one or more network nodes with base stations, it is clear that various operations that are performed so as to communicate with terminals can be performed by base stations, one or more network nodes (for example, MMEs (Mobility Management Entities), S-GWs (Serving-Gateways) and so on may be possible, but these are not limiting) other than base stations, or combinations of these.

The aspects/embodiments illustrated in this specification may be applied to systems that use LTE (Long Term Evolution), LTE-A (LTE-Advanced), LTE-B (LTE-Beyond), SUPER <NUM>, IMT-Advanced, <NUM> (4th generation mobile communication system), <NUM> (5th generation mobile communication system), FRA (Future Radio Access), New-RAT (Radio Access Technology), NR(New Radio), NX (New radio access), FX (Future generation radio access), GSM (registered trademark) (Global System for Mobile communications), CDMA <NUM>, UMB (Ultra Mobile Broadband), IEEE <NUM> (Wi-Fi (registered trademark)), IEEE <NUM> (WiMAX (registered trademark)), IEEE <NUM>, UWB (Ultra-WideBand), Bluetooth (registered trademark) and other adequate radio communication methods, and/or next-generation systems that are enhanced based on these.

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 herein only for convenience, as a method of distinguishing between two or more elements. In this way, reference to the first and second elements does not imply that only two elements may be employed, or that the first element must precede the second element in some way.

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.

As used herein, two elements may be considered "connected" or "coupled" to each other by using one or more electrical wires, cables and/or printed electrical connections, and, as a number of non-limiting and non-inclusive examples, by using electromagnetic energy, such as electromagnetic energy having wavelengths in radio frequency regions, microwave regions and optical regions (both visible and invisible).

In the present specification, the phrase "A and B are different" may mean "A and B are different from each other. " The terms such as "leave" "coupled" and the like may be interpreted as well.

Now, although the present invention has been described in detail above, it should be obvious to a person skilled in the art that the present invention is by no means limited to the embodiments described herein. The scope of protection of the invention is defined in the appended set of claims.

Claim 1:
A terminal (<NUM>) configured to operate in a 3GPP system, the terminal comprising:
a control section (<NUM>) configured to use resource information indicated by a resource indicator field in downlink control information, out of a plurality of resource information configured by higher layer signaling, to control the transmission of uplink control information, UCI, on a physical uplink control channel, PUCCH,
wherein the resource information includes a specific cyclic shift, CS, index, and the control section (<NUM>) is configured to determine a CS index based on the specific CS index and the UCI; and
a transmitting section (<NUM>) configured to transmit a sequence using the CS index in the PUCCH,
wherein when the UCI includes Hybrid Automatic Repeat reQuest-ACKnowledgement, HARQ-ACK, information with a negative Scheduling Request, SR, the CS index is the specific CS index;
wherein when the UCI includes the HARQ-ACK information with a positive SR, the CS index is obtained by adding a CS offset to the specific CS index.