Patent Description:
In the standardization of <NUM>, 3GPP has been discussing a new radio access technology (NR) that is not necessarily backward compatible with LTE/LTE-Advanced.

Studies have been conducted on operating the NR in unlicensed bands, which requires no license, in addition to licensed bands, which requires a license, as is the case with LTE License-Assisted Access (LAA) (see, for example, Non Patent Literature (hereinafter, referred to as NPL) <NUM>). The operation in unlicensed bands is called, for example, NR-based Access to Unlicensed Spectrum (NR-U).

<CIT>
discloses a signal transmission method, which comprises receiving first indication information sent by a network device, wherein the first indication information is used for indicating an uplink resource allocated by the network device to a terminal on a first bandwidth, and the resource indicated by the first indication information comprises an integer number of resource blocks uniformly distributed on part or all of the first bandwidth, carrying out uplink transmission on a monitored idle second bandwidth, and sending second indication information to the network device, wherein the second indication information is used for indicating the second bandwidth. <CIT> discloses a resource allocation indication method, comprising a network device, which acquires the maximum number of resource blocks that a user equipment can schedule and that the network device can allocate to the UE. The network device calculates the resource indication value, according to the maximum number of resource blocks that the UE can schedule and that the network device can allocate to the UE, and the number of resource blocks corresponding to bandwidth that the network device can allocate to all UE for use, and transmits the calculated resource indication value to the UE.

However, signal transmission/reception methods in the operation in unlicensed bands have not been comprehensively studied.

One non-limiting and exemplary embodiment facilitates providing a transmission apparatus, a reception apparatus, a transmission method, and a reception method each capable of appropriately transmitting/receiving signals in the operation in unlicensed bands. The invention is defined in the appended independent claims. Advantageous and preferred embodiments of the present invention are defined by the dependent claims. Examples, aspects and embodiments mentioned in the following, but not necessarily falling under the scope of the claims are provided in the application to better understand the invention.

According to an embodiment of the present disclosure, it is possible to appropriately transmit/receive signals in the operation in unlicensed bands.

In unlicensed bands, the upper limit of Power Spectral Density (PSD) is defined by laws, regulations, and standards, for example. The European Telecommunications Standards Institute (ETSI), for example, imposes the upper limit of <NUM> dBm/MHz (<NUM> dBm/Hz depending on the band), for example, for the PSD in the <NUM> band on terminals (also referred to as mobile stations or User Equipment (UE)) having a power control function.

In order to transmit signals with higher transmission power under the limitation of the PSD, it is effective to spread resources on frequency domain and map the signals. In this regard, studies have been carried out on applying a PRB-based block interlace design (also referred to as block-interleaved frequency division multiple access (B-IFDMA)) as a frequency resource allocation method (see, for example, NPL <NUM>).

<FIG> illustrates an exemplary PRB-based block interlace design.

The PRB-based block interlace design is used as a frequency resource allocation method for a Physical Uplink Shared Channel (PUSCH), which is an uplink data channel in LTE-LAA. The PRB-based block interlace design is a method of transmitting signals using a band (i.e., resource) called interlaces that are distributed at certain intervals on the frequency domain in a system band, in order to comply with the limitation of an Occupied Channel Bandwidth (OCB) in unlicensed bands defined by the ETSI and to mitigate the effect of the PSD limitation.

The interlace is composed of, for example, a group of contiguous subcarriers (e.g., <NUM> Physical Resource Block (PRB)). For example, a plurality of interlaces are included in a band (hereinafter, referred to as a cluster or a cluster block) resulting from dividing the system band or a bandwidth part (BWP) of the system band into a plurality of blocks. The interlaces included in each cluster have respective numbers (hereinafter referred to as "interlace numbers").

Note that the cluster means similar to, for example, the "interval" at which the interlaces with the same interlace number are arranged. That is, the interlaces with the same interlace number are evenly distributed on the frequency domain over the plurality of clusters.

For example, the frequency resource allocation method for the PUSCH in LTE-LAA (e.g., also referred to as uplink resource allocation type <NUM>) uses the PRB-based block interlace design where the number of interlaces (hereinafter, represented as "M") is <NUM> and the number of PRBs per interlace (hereinafter, represented as "N"; i.e., the number of clusters) is <NUM> PRBs, as illustrated in <FIG>. In addition, the system bandwidth in LTE-LAA is maximum <NUM> (<NUM> PRBs), and subcarrier spacing (SCS) is fixed at <NUM>.

The frequency resource allocation for the PUSCH for the terminal is determined by, for example, a base station (e.g., also referred to as Node B or gNB). The base station indicates the determined frequency resource allocation information (e.g., also referred to as a resource allocation field) to the terminal by including in Downlink Control Information (DCI), for example.

Herein, the frequency resource allocation information is composed of, for example, a resource indication value (RIV) that is control information uniquely associated with a combination of the interlace number of a starting position (e.g., a starting PRB: RBSTART) in the cluster and the contiguous allocation length (i.e., the number of PRBs; e.g., L) from the starting position, as illustrated in <FIG>. Hereinafter, a method of indicating the frequency resource by the combination of the starting position of the resource and the resource length consecutively used from the starting position is referred to as an "RIV-based allocation method".

LTE-LAA has <NUM> combinations of RBSTART and L since M = <NUM>. Thus, the frequency resource allocation information (RIV) has an information amount of <NUM> bits. In addition, the interlace allocation in a cluster indicated by the RIV is applied to all clusters in the system band.

Meanwhile, values indicated in <FIG> have been studied in NR-U, for example, in terms of the number of interlaces (M) and the number of PRBs (N) per interlace (see, for example, NPL <NUM>).

For example, studies have been carried out on supporting a plurality of SCSs and supporting different numbers of interlaces (M) for different SCSs in NR-U, as illustrated in <FIG>.

Studies have also been carried out on supporting a plurality of system bands (BWPs) with different bandwidths in NR-U. <FIG> illustrates an exemplary configuration of the system band where <NUM> = <NUM> PRBs, SCS = <NUM>, M = <NUM>, and N = <NUM> or <NUM>. In <FIG>, the interlace numbers #<NUM>, <NUM>,. , <NUM> are assigned to the respective interlaces in the clusters.

As illustrated in <FIG>, the cluster at the end of the system band (cluster #<NUM> in <FIG>) sometimes has a bandwidth different from the bandwidths of the other clusters depending on the system bandwidth. For example, the bandwidths of clusters #<NUM> to #<NUM> are <NUM> PRBs each, whereas the bandwidth of cluster #<NUM> is <NUM> PRBs (interlaces #<NUM> to #<NUM>) in <FIG>. Thus, N = <NUM> for interlaces #<NUM> to #<NUM>, and N = <NUM> for interlaces #<NUM> to #<NUM> in <FIG>.

Further, studies have been conducted in NR-U on supporting a system bandwidth of <NUM> or more and indicating the frequency resource allocation for the entire system band by a single DCI.

Thus, the frequency resource allocation method for NR-U needs to take into account the system bandwidth of <NUM> or more, in contrast to the frequency resource allocation method for LTE-LAA.

In addition, the system bandwidth (or BWP) is different for each terminal in NR-U in some cases. It is thus required to be capable of performing flexible frequency multiplexing among the terminals configured with different system bandwidths.

Further, since NR-U supports a plurality of SCSs, it is required to discuss the frequency resource allocation method suitable for each SCS. It is also required to discuss a case of using the RIV-based frequency resource allocation method.

Thus, descriptions will be given below of transmission and reception methods for uplink signals in NR-U.

The communication system according to an embodiment of the present disclosure includes base station <NUM> and terminal <NUM>. In the following description, base station <NUM> (corresponding to a reception apparatus) determines a frequency resource to be allocated to terminal <NUM>, and indicates information indicating the determined resource, by way of example. Then, terminal <NUM> (corresponding to a transmission apparatus) performs signal transmission processing including mapping to the resource based on the indicated information, and transmits the signal to base station <NUM>.

<FIG> is a block diagram illustrating an example of a configuration of a part of base station <NUM> according to an embodiment of the present disclosure. In base station <NUM> illustrated in <FIG>, scheduler <NUM> determines allocation (e.g., cluster RA) of groups among a plurality of groups (e.g., cluster groups) resulting from grouping a plurality of blocks (e.g., clusters) into which the frequency band is divided, and allocation (e.g., interlace RA) of resources (e.g., interlaces) in the blocks. Receiver <NUM> receives signals based on the allocation of the groups and the allocation of the resources.

<FIG> is a block diagram illustrating an example of a configuration of a part of terminal <NUM> according to an embodiment of the present disclosure. In terminal <NUM> illustrated in <FIG>, mapper <NUM> assigns signals to the resources based on control information indicating the allocation (e.g., cluster RA) of the groups among the plurality of groups (e.g., cluster groups) resulting from grouping the plurality of blocks (e.g., clusters) into which the frequency band is divided, and the allocation (e.g., interlace RA) of the resources (e.g., interlaces) in the blocks. Transmitter <NUM> transmits the signals.

<FIG> is a block diagram illustrating the configuration of base station <NUM> according to the present embodiment.

In <FIG>, base station <NUM> includes scheduler <NUM>, holder <NUM>, modulator <NUM>, transmitter <NUM>, antenna <NUM>, receiver <NUM>, Fast Fourier Transformer (FFT) <NUM>, demapper <NUM>, Inverse Discrete Fourier Transformer (IDFT) <NUM>, and demodulator/decoder <NUM>.

Scheduler <NUM> determines radio resource allocation (e.g., frequency resource allocation, time resource allocation, or transmit power control information) for an uplink data channel (PUSCH) for terminal <NUM> connected to base station <NUM>. Scheduler <NUM> outputs the determined radio resource allocation information to holder <NUM> and modulator <NUM>.

Herein, the frequency resource allocation is determined by, for example, frequency resource allocation for the interlaces in a cluster (hereinafter, referred to as interlace resource allocation (interlace RA)) and frequency resource allocation for the cluster groups (hereinafter, referred to as cluster resource allocation (cluster RA)), in accordance with rules to be described later. In other words, the frequency resource allocation information indicated to terminal <NUM> is composed of <NUM> types of frequency resource allocation information, which are the interlace RA information and the cluster RA information.

Note that the "cluster group" means a band including one or a plurality of contiguous clusters on the frequency domain, for example.

The bandwidth or SCS of the BWP of terminal <NUM> may be indicated in advance from base station <NUM> to terminal <NUM> by, for example, higher layer signaling (also referred to as Radio Resource Control signaling (RRC signaling)). Additionally, part of the information of the frequency resource allocation may be transmitted by the higher layer signaling.

For example, the interlace RA information may be transmitted by the DCI, and the cluster RA information may be transmitted by the higher layer signaling. This allows scheduler <NUM> to dynamically control the interlace allocation in the cluster according to communication quality, for example. Meanwhile, an average variation of the communication quality among cluster groups is relatively small, and thus, while static control using the higher layer signaling for the cluster RA gives little effect on the performance, the signaling overhead can be reduced.

Holder <NUM> holds the frequency resource allocation information (including, for example, the interlace RA information and the cluster RA information) inputted from scheduler <NUM> in order to receive a signal transmitted from terminal <NUM> for which the frequency resource has been allocated, and outputs the information to demapper <NUM> in receiving the signal of the intended terminal <NUM>.

Modulator <NUM> generates the DCI based on the radio resource allocation information inputted from scheduler <NUM>, modulates the generated DCI, and outputs the DCI to transmitter <NUM>.

Transmitter <NUM> performs transmission processing such as D/A conversion, up-conversion, and amplification on the signal inputted from modulator <NUM>, and transmits the signal after the transmission processing from antenna <NUM>.

Receiver <NUM> receives a signal transmitted from terminal <NUM> via antenna <NUM>, performs reception processing such as down-conversion and A/D conversion on the received signal, and outputs the received signal after the reception processing to FFT <NUM>.

FFT <NUM> removes a Cyclic Prefix (CP) portion from the received signal inputted from receiver <NUM>, converts the signal into a signal on the frequency domain by FFT processing, and outputs the signal on the frequency domain to demapper <NUM>.

Demapper <NUM> extracts a signal corresponding to the frequency resource allocated to the intended terminal <NUM> from the signal on the frequency domain inputted from FFT <NUM>, based on the interlace RA information and the cluster RA information for the intended terminal <NUM> inputted from holder <NUM>. Demapper <NUM> outputs the extracted signal to IDFT <NUM>.

IDFT <NUM> performs IDFT processing on the signal inputted from demapper <NUM>, and outputs the signal to demodulator/decoder <NUM>. Note that IDFT <NUM> (IDFT processing) is required when terminal <NUM> transmits a Discrete Fourier Transform-spread Orthogonal Frequency Division Multiplexing (DFT-S-OFDM) signal. IDFT <NUM> (IDFT processing) is not required when terminal <NUM> transmits an OFDM signal. The transmission method (DFT-S-OFDM or OFDM) of terminal <NUM> may be determined in advance by base station <NUM> based on a communication state (e.g., powerhead room of transmission power) of terminal <NUM>, and indicated to terminal <NUM> by the higher layer signaling, for example.

Demodulator/decoder <NUM> performs demodulation processing and decoding processing on the signal inputted from IDFT <NUM>, and outputs the received data.

<FIG> is a block diagram illustrating the configuration of terminal <NUM> according to the present embodiment.

In <FIG>, terminal <NUM> includes antenna <NUM>, receiver <NUM>, demodulator <NUM>, frequency resource allocation calculator <NUM>, encoder/modulator <NUM>, DFT <NUM>, mapper <NUM>, IFFT <NUM>, and transmitter <NUM>.

Receiver <NUM> receives a signal transmitted from base station <NUM> via antenna <NUM>, performs reception processing such as down-conversion and A/D conversion on the received signal, and outputs the received signal after the reception processing to demodulator <NUM>.

Demodulator <NUM> demodulates the received signal inputted from receiver <NUM>, and outputs the demodulated DCI to frequency resource allocation calculator <NUM>.

Frequency resource allocation calculator <NUM> calculates the frequency resource allocation information (e.g., the interlace RA information and the cluster RA information) based on the DCI inputted from demodulator <NUM>, and outputs the information to mapper <NUM>.

Encoder/modulator <NUM> encodes and modulates transmission data (i.e., uplink data), and outputs the modulated data signal to DFT <NUM>.

DFT <NUM> performs DFT processing on the data signal inputted from encoder/modulator <NUM>, and outputs the signal after the DFT processing to mapper <NUM>. Note that DFT <NUM> (DFT processing) is required when terminal <NUM> transmits a DFT-S-OFDM signal. DFT <NUM> (DFT processing) is not required when terminal <NUM> transmits an OFDM signal.

Mapper <NUM> maps (i.e., assigns) the data signal inputted from DFT <NUM> to the frequency resource based on the frequency resource allocation information inputted from frequency resource allocation calculator <NUM>. For example, mapper <NUM> maps the data signal to the frequency resource with an indicated interlace number in clusters included in an indicated cluster group. Mapper <NUM> outputs the mapped data signal to IFFT <NUM>.

IFFT <NUM> performs IFFT processing on the signal inputted from mapper <NUM>, and outputs the signal with the CP added to transmitter <NUM>.

Transmitter <NUM> performs transmission processing such as D/A conversion, up-conversion, and amplification on the signal inputted from IFFT <NUM>, and transmits the signal after the transmission processing from antenna <NUM>.

Exemplary operations in base station <NUM> and terminal <NUM> including the above-described configurations will be described.

<FIG> is a sequence diagram describing the exemplary operations in base station <NUM> (<FIG>) and terminal <NUM> (<FIG>).

In <FIG>, base station <NUM> performs scheduling for terminal <NUM> (ST101).

Base station <NUM> transmits, for example, the radio resource allocation information indicating the scheduling result for terminal <NUM> to terminal <NUM> (ST102). The radio resource allocation information includes the frequency resource allocation information including, for example, the interlace RA information and the cluster RA information. Note that each of the interlace RA information and the cluster RA information may be indicated from base station <NUM> to terminal <NUM> by the higher layer signaling or the DCI, as described above. Terminal <NUM> acquires the frequency resource allocation information indicated from base station <NUM> (ST103).

Terminal <NUM> maps data (e.g., a PUSCH signal) to the resource based on the acquired frequency resource allocation information (ST104). Terminal <NUM> transmits the data mapped to the resource to base station <NUM> (ST105).

Base station <NUM> extracts the data transmitted from terminal <NUM> based on the frequency resource allocated to terminal <NUM> (ST106).

Next, an exemplary frequency resource allocation method in scheduler <NUM> will be described.

<FIG> illustrates an exemplary frequency resource allocation applying the PRB-based block interlace design according to the present embodiment.

The frequency resource allocation according to the present embodiment is performed by combining the frequency resource allocation for interlaces in clusters (interlace RA) and the frequency resource allocation for cluster groups in a system band or a BWP (cluster RA).

Herein, the "cluster group" means a band including one or contiguous clusters on the frequency domain. In other words, the cluster group is configured by grouping a plurality of clusters resulting from dividing the frequency band such as the system band or the BWP.

In addition, the "interlace RA" indicates a resource of the allocated interlaces in the clusters. In other words, the interlace RA indicates the interlace resource allocation in the clusters for terminal <NUM>.

Further, the "cluster RA" indicates a resource of the allocated cluster groups in the BWP (or system band). In other words, the cluster RA indicates the cluster group allocation among the plurality of cluster groups for terminal <NUM>.

Note that <FIG> illustrates the interlace RA and the cluster RA both applying the RIV-based allocation (combination of the starting resource position and the resource length consecutively used), by way of example, but the allocation method is not limited to this. For example, the interlace RA or the cluster RA may apply a method of indicating information of whether to allocate for each resource unit (PRB unit or cluster group unit), i.e., information of whether each interlace in the clusters is allocated. Hereinafter, the method is referred to as bitmap-based allocation.

In <FIG>, for example, the cluster RA is configured with ClusterSTART = <NUM> and Lcluster = <NUM> for terminal <NUM>. Terminal <NUM> then determines that two cluster groups of cluster groups #<NUM> and #<NUM> among cluster groups #<NUM> to #X in the BWP (e.g., also referred to as UL BWP) are allocated.

In addition, the interlace RA is configured with RBSTART = <NUM> and L = <NUM> for terminal <NUM> in <FIG>, for example. Terminal <NUM> then determines that three interlaces of interlaces #<NUM> to #<NUM> are allocated.

Thus, terminal <NUM> determines that interlaces #<NUM> to #<NUM> in cluster groups #<NUM> and #<NUM> are allocated in <FIG>.

In the present embodiment, the cluster RA is indicated in addition to the interlace RA, as described above. This enables allocation of different cluster groups (i.e., different clusters) for different terminals <NUM> even when the different system bandwidths (or BWPs) are configured to those terminals <NUM>, for example. Thus, according to the present embodiment, it is possible to flexibly perform frequency multiplexing among terminals <NUM> configured with different system bandwidths or BWPs, for example.

Next, exemplary configurations of the cluster groups will be described.

The cluster groups are configured on Listen Before Talk (LBT) subbands (also referred to as LBT units), for example, as illustrated in <FIG>. The LBT subband is a band where terminal <NUM> and base station <NUM> perform carrier sensing. The bandwidth of the LBT subband (including a guard band) is <NUM>, for example.

In the example illustrated in <FIG>, the BWP is <NUM> (<NUM> PRBs) and the cluster group is configured for each LBT subband (<NUM> PRBs). For example, the BWP, which is <NUM> (<NUM> PRBs), is divided into the cluster groups of <NUM> PRBs each in <FIG>.

This allows base station <NUM> to control the frequency resource allocation in cluster group units according to an interference state of terminal <NUM> in each LBT subband. Thus, base station <NUM> can appropriately perform frequency scheduling for terminal <NUM> even in the system bandwidth (or BWP) of <NUM> or more, for example.

Note that, as illustrated in <FIG>, the bandwidths of the clusters at both ends of the cluster groups (<NUM> PRBs, <NUM> PRBs, or <NUM> PRBs in <FIG>) may be different from the bandwidths of the other clusters (<NUM> PRBs in <FIG>).

As illustrated in <FIG>, the cluster groups may be configured by dividing the LBT subband (e.g., <NUM>, <NUM> PRBs) in units of clusters such that the cluster groups have substantially the same number of clusters, for example.

In the example illustrated in <FIG>, the BWP is <NUM> (<NUM> PRBs) and divided into two cluster groups. The cluster group on the first half (i.e., lower frequency side) illustrated in <FIG> is composed of <NUM> PRBs of five clusters #<NUM> to #<NUM>. The cluster group on the second half (i.e., higher frequency side) is composed of <NUM> PRBs of six clusters #<NUM> to #<NUM>.

This allows base station <NUM> to increase the number of terminals <NUM> to be frequency-multiplexed in the LBT subband.

The cluster group is composed of the minimum number of clusters having a bandwidth equal to or wider than the specified minimum bandwidth, and the minimum number of clusters makes a bandwidth of the cluster group. For example, as illustrated in <FIG>, each cluster group is composed of two clusters that is a minimum number having a bandwidth of <NUM> or more.

<NUM> indicates the minimum bandwidth in a regulation of a temporarily operation in the OCB specification defined by the ETSI. The regulation states that, as long as some signals satisfy the OCB specification of <NUM>-<NUM>%, other signals only need to be <NUM> or more in the same COT. In the example illustrated in <FIG>, each cluster group is thus composed of two clusters with the minimum bandwidth of <NUM> or more. Note that the minimum bandwidth is not limited to <NUM>, and may be another bandwidth.

This allows base station <NUM> to perform the frequency scheduling for each terminal with finer granularity while satisfying the OCB specification.

The exemplary configurations of the cluster groups have been described, thus far.

Here comes to a discussion on a case of indicating the interlace RA for each cluster group (e.g., for each LBT subband) instead of the cluster RA. When the BWP is <NUM>, for example, four interlace RAs for respective LBT subbands (<NUM> each) are indicated to terminal <NUM>. For the number of signaling bits of each interlace RA, the number of contiguous interlace allocation patterns is determined according to the number of interlaces (M). When M = <NUM>, for example, the interlace RA includes <NUM> signaling bits. Thus, the total number of signaling bits of the four interlace RAs is determined to be <NUM> bits by multiplying <NUM> by <NUM> in this case.

In the present embodiment, in contrast, the cluster RA includes <NUM> signaling bits when, for example, the BWP is <NUM> and the cluster RA for each LBT subband (<NUM>) is indicated on the RIV or bitmap basis. When M = <NUM>, for example, the interlace RA includes <NUM> signaling bits. Thus, when the BWP is <NUM>, the total number of signaling bits of the interlace RA and the cluster RA is determined to be <NUM> bits by adding <NUM> to <NUM>.

The present embodiment thus enables reducing overhead compared with the case of indicating the interlace RA for each cluster group. This allows base station <NUM> to appropriately perform the frequency scheduling for terminal <NUM> while reducing the signaling overhead even in the system bandwidth (or BWP) of <NUM> or more, for example.

Additionally, when each cluster RA has the same bandwidth, the number of terminals that can be frequency-multiplexed in the same slot is the same as in the above-described method of transmitting a plurality of interlace RAs. Further, signals can still be distributed throughout the cluster group length in the method illustrated in <FIG>, thereby achieving the frequency diversity gain equivalent to that in the above-described method of transmitting a plurality of interlace RAs. Although the interlace allocation (allocation of interlace #<NUM> in <FIG>) is the same among the cluster groups in the method illustrated in <FIG>, flexibility of scheduling can be improved by, for example, adjusting the bandwidths of the cluster groups according to the number of terminals <NUM> in a cell. When there is a large number of terminals <NUM>, for example, the flexibility of scheduling can be improved by configuring narrower bandwidths for the cluster groups (configuring finer allocation granularity for the clusters), and by frequency-multiplexing a plurality of terminals among the cluster groups.

Next, exemplary configurations of the interlace RA will be described.

Hereinafter, the RIV-based allocation method is applied to the interlace RA, by way of example.

<FIG> illustrates exemplary RIVs. The RIV indicates, for example, the combination of the allocation starting position (e.g., PRB number "RBstart") of the interlace resources in a single cluster and the number of resources (length) L consecutively allocated from the allocation starting position. <FIG> illustrates exemplary RIV patterns (i.e., interlace allocation patterns indicated by the allocation starting position and the number of resources) in a case where the number of interlaces (M) is <NUM>. The RIV indicated from base station <NUM> to terminal <NUM> indicates any of the interlace allocation patterns illustrated in <FIG>.

The allocation patterns of contiguous interlaces on the frequency domain depend on the number of interlaces. In the example of <FIG>, the allocation patterns of contiguous interlaces indicated by the RIV includes <NUM>C<NUM> = <NUM> patterns, which is information of at least <NUM> bits.

Herein, application of the RIV-based allocation method makes it possible to add allocation patterns different from the allocation patterns of the contiguous interlaces (e.g., allocation patterns of non-contiguous interlaces) while preventing the increase in the number of signaling bits. In <FIG>, for example, the number of signaling bits does not increase even in a case of adding <NUM> patterns corresponding to the remaining RIVs, which is from <NUM> to <NUM>, to the RIVs from <NUM> to <NUM> corresponding to the contiguous interlace patterns.

Exemplary configurations of the RIV-based interlace RA will be described below.

In Configuration Example <NUM>, as illustrated in <FIG>, the allocation patterns (e.g., RIVs = <NUM> to <NUM>) of the contiguous interlaces are configured for the first number of interlaces (e.g., M = <NUM>), and other allocation patterns of interlaces are also configured (i.e., added) for the second number of interlaces (e.g., M = <NUM>) that is different from the first number of interlaces, for example.

<FIG> includes additional allocation patterns of interlaces for the RIVs <NUM> to <NUM>, for example. The allocation patterns are for interlaces with the contiguous allocation length of <NUM> PRB (i.e., L = <NUM>) in a cluster where M = <NUM>.

In Configuration Example <NUM>, the interlace RA information includes the interlace allocation patterns for different numbers of interlaces in a cluster (M = <NUM> and M = <NUM>, in <FIG>) as described above. This allows base station <NUM> to dynamically change the minimum allocation bandwidth for a single terminal <NUM> using the DCI while preventing the increase in the signaling overhead.

When M = <NUM>, for example, the minimum allocation bandwidth (corresponding to N) is <NUM> PRBs. Meanwhile, the minimum allocation bandwidth (corresponding to N) is <NUM> PRBs for the interlace allocation patterns to satisfy the OCB specification when M = <NUM> and the contiguous allocation length is <NUM> PRB in the cluster.

When the minimum allocation bandwidth is narrowed, it is possible to allocate a resource with a narrow bandwidth to a cell-edge terminal that requires transmission power to compensate for path loss, for example, thus reducing performance deterioration of the terminal due to a transmission power shortage. Incidentally, the PRB-based block interlace design focuses on the frequency diversity gain. In this regard, the interlace allocation with the contiguous allocation length (L) limited to <NUM> PRB still causes signals to be distributed throughout the band corresponding to the cluster group, thereby obtaining sufficient frequency diversity gain.

Note that the RIVs need not include the interlace allocation patterns for all the allocation lengths (L). As illustrated in <FIG>, the interlace allocation patterns for some allocation lengths (L) may be excluded in the interlace where M = <NUM>, for example. In <FIG>, the allocation lengths L = {<NUM>, <NUM>, <NUM>, <NUM>} are excluded, and it is limited to the allocation lengths L = {<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>} in the interlace where M = <NUM>, by way of example.

As illustrated in <FIG>, evenly thinning some of the indicatable allocation lengths L prevents flexibility in scheduling allocation from greatly deteriorating. Further, more of other patterns for the different number of interlaces (M) can be added to replace the excluded patterns, thereby improving scheduling gain. For example, it is possible to add all the allocation patterns for the case where M = <NUM> and L = <NUM> (i.e., patterns for the case where RBstart = <NUM> to <NUM>) in <FIG>. The addition of the patterns for the case where M = <NUM> and interlace allocation length L = <NUM> increases the number of terminals that can be frequency-multiplexed, and narrows the minimum bandwidth per terminal. In addition, the patterns for the case where L = <NUM> still causes signals to be distributed throughout the band corresponding to the cluster group, thus obtaining sufficient frequency diversity gain.

In Configuration Example <NUM>, as illustrated in <FIG>, an allocation pattern of no uplink data transmission (No transmission) is added to the contiguous interlace patterns for the first number of interlaces (e.g., M = <NUM>), for example.

This allows base station <NUM> to indicate the no uplink data transmission to intended terminal <NUM> using the DCI while preventing the increase in the signaling overhead.

For example, when an uplink data band is allocated to another terminal <NUM> and it is required to indicate a single transmission of an SRS (Sounding Reference Signal), base station <NUM> can indicate the No transmission by the RIV (e.g., RIV = <NUM> in <FIG>), and this indicates the single transmission of the SRS.

Alternatively, when a plurality of interlace RAs are indicated for each cluster group (e.g., for each LBT subband) as described above, base station <NUM> can independently indicate the No transmission in each interlace RA, thereby controlling the frequency resource to be allocated to terminal <NUM> in units of the cluster groups.

In Configuration Example <NUM>, as illustrated in <FIG>, partial allocation patterns in the cluster group (i.e., allocation patterns for part of the group) are added to the contiguous interlace patterns for a certain number of interlaces (e.g., M = <NUM>), for example.

For example, RIVs <NUM> to <NUM> configure the interlace allocation patterns for all clusters in the cluster group allocated by the cluster RA, in <FIG>.

In addition, RIVs <NUM> to <NUM> configure the interlace allocation patterns for the first half of the clusters (e.g., clusters on a lower frequency side) in the cluster group allocated by the cluster RA, in <FIG>. In other words, the second half of the clusters in the cluster group allocated by the cluster RA are not allocated to terminal <NUM> by the RIVs <NUM> to <NUM> illustrated in <FIG>.

Likewise, RIVs <NUM> to <NUM> configure the interlace allocation patterns for the second half of the clusters (e.g., clusters on a higher frequency side) in the cluster group allocated by the cluster RA, in <FIG>. In other words, the first half of the clusters in the cluster group allocated by the cluster RA are not allocated to terminal <NUM> by the RIVs <NUM> to <NUM> illustrated in <FIG>.

This allows base station <NUM> to dynamically control (i.e., schedule) the partial interlace allocation in the cluster group allocated to terminal <NUM> (e.g., the cluster group allocated by the cluster RA), for example. It is also possible to narrow the minimum bandwidth for terminal <NUM> while preventing the increase in the signaling overhead.

Configuration Example <NUM> focuses on a relation between the number of interlaces (M) and the number of signaling bits in the RIV-based allocation method and the bitmap-based allocation method.

<FIG> illustrates exemplary relations between the number of interlaces (M) and the number of signaling bits in the RIV-based allocation method and the bitmap-based allocation method. The horizontal axis indicates the number of interlaces (M) and the vertical axis indicates the number of signaling bits in <FIG>.

As illustrated in <FIG>, there is a small difference in the number of signaling bits between the RIV-based allocation method and the bitmap-based allocation method when M is small. For example, there is no difference in the number of signaling bits between the RIV-based allocation method and the bitmap-based allocation method when M is <NUM> or less. When M is <NUM> or <NUM>, there is a difference of <NUM> bit between the RIV-based allocation method and the bitmap-based allocation method.

Incidentally, studies have been conducted in NR-U on supporting, for example, the number of interlaces M of <NUM> or less when SCS = <NUM> and <NUM>, as illustrated in <FIG>.

In this regard, Configuration Example <NUM> applies, as illustrated in <FIG>, the RIV-based allocation method to the interlace RA when the SCS is equal to or less than a threshold (e.g., <NUM>), and applies the bitmap-based allocation method to the interlace RA when the SCS is greater than the threshold (e.g., <NUM>), for example.

Thus, the RIV-based allocation method is applied, for example, for the SCS (e.g., <NUM>) that has a narrow bandwidth per <NUM> PRB and applies a relatively large number of interlaces (M). This reduces the signaling overhead.

In contrast, the bitmap-based allocation method is applied for the SCS (e.g., <NUM> or <NUM>) that has a large bandwidth per <NUM> PRB and applies a relatively small number of interlaces (M). This enables the allocation including non-contiguous interlace allocation patterns by the bitmap while preventing the increase in the signaling overhead, thereby improving the scheduling gain.

As described above, Configuration Example <NUM> makes it possible to apply the frequency resource allocation method suitable for the SCS.

In Configuration Example <NUM>, the allocation pattern of contiguous virtual interlaces is indicated as the interlace RA information. In other words, the interlace RA information indicates contiguous virtual interlace numbers.

For example, base station <NUM> indicates a contiguous interlace allocation pattern to terminal <NUM> using virtual interlace numbers (PRB numbers). Terminal <NUM> converts the indicated virtual interlace numbers (PRB numbers) into actual interlace numbers (PRB numbers) according to a rule determined between base station <NUM> and terminal <NUM>. Terminal <NUM> assigns signals to the interlaces with the actual interlace numbers that have been converted.

In the example illustrated in <FIG>, virtual interlace numbers #<NUM> to #<NUM> are respectively assigned to the interlaces (i.e., PRBs) in the cluster, for example. In the example illustrated in <FIG>, the actual interlace numbers are numbers obtained by cyclically shifting virtual interlace numbers #<NUM> to #<NUM> by <NUM> PRBs in each cluster. In other words, the rule for converting the virtual interlace numbers to the actual interlace numbers is the same among a plurality of clusters in <FIG>.

In <FIG>, base station <NUM> indicates the contiguous interlace allocation pattern of virtual interlace numbers #<NUM> to #<NUM> to terminal <NUM> by the RIV-based allocation method.

In <FIG>, terminal <NUM> converts the virtual interlace numbers in the cluster to the actual interlace numbers by cyclically shifting by <NUM> PRBs in all the clusters, for example. This makes it possible to allocate the interlaces distributed at both ends of each cluster (e.g., interlaces #<NUM>, #<NUM> and interlace #<NUM>) to terminal <NUM> in <FIG>. Processing is also simplified in <FIG> by applying the same rule for converting the virtual interlace numbers to the actual interlace numbers to the plurality of clusters.

Next, in the example illustrated in <FIG>, virtual interlace numbers #<NUM> to #<NUM> are respectively allocated to the interlaces (i.e., PRBs) in the cluster, as in <FIG>. In the examples illustrated in <FIG>, the actual interlace numbers in cluster #X are numbers obtained by cyclically shifting virtual interlace numbers #<NUM> to #<NUM> by <NUM> PRBs, and the actual interlace numbers in cluster #Y are numbers obtained by cyclically shifting virtual interlace numbers #<NUM> to #<NUM> by <NUM> PRBs. In other words, the rule for converting the virtual interlace numbers to the actual interlace numbers is different among a plurality of clusters in <FIG>.

In <FIG>, terminal <NUM> converts the virtual interlace numbers to the actual interlace numbers, for example, according to the rule predetermined for each cluster. For example, terminal <NUM> cyclically shifts the virtual interlace numbers by <NUM> PRBs in cluster number X in <FIG>. In addition, terminal <NUM> cyclically shifts the virtual interlace numbers by <NUM> PRBs in cluster number Y.

Transmission resources allocated to terminal <NUM> can be randomized by applying different rules for converting the virtual interlace numbers to the actual interlace numbers to the clusters, as described above. This randomizes interference to another cell and improves a system performance.

In Configuration Example <NUM>, the conversion from the virtual allocation to the actual allocation in terminal <NUM> enables the non-contiguous interlace allocation in the cluster, as described above, thereby improving the frequency diversity gain.

Further, in Configuration Example <NUM>, the indication of the contiguous virtual interlace allocation pattern by the RIV-based allocation method reduces the signaling overhead.

Note that, although Configuration Example <NUM> has described the case of converting the virtual interlace numbers to the actual interlace numbers by the cyclic shift, the conversion rule is not limited to this. For example, the contiguous virtual interlace numbers may be indicated in the interlace RA information, and the actual interlace numbers corresponding to the contiguous virtual interlace numbers may be associated with non-contiguous interlaces.

The exemplary configurations of the interlace RA have been described, thus far.

Next, exemplary configurations of the cluster RA will be described.

In Configuration Example <NUM>, the allocation pattern of contiguous virtual cluster groups is indicated as the cluster RA information. In other words, the cluster RA information indicates contiguous virtual cluster group numbers.

For example, base station <NUM> indicates a contiguous cluster group allocation pattern to terminal <NUM> using the virtual cluster group numbers. Terminal <NUM> converts the indicated virtual cluster group numbers to actual cluster group numbers according to a rule predetermined between base station <NUM> and terminal <NUM>. Terminal <NUM> assigns signals to the clusters in the cluster groups with the actual cluster group numbers that have been converted.

For example, in the example illustrated in <FIG>, virtual interlace numbers #<NUM> to #X are respectively assigned to the cluster groups in the BWP. In the examples illustrated in <FIG>, the actual cluster group numbers are numbers obtained by cyclically shifting virtual interlace numbers #<NUM> to #X by -<NUM> in the BWP.

In <FIG>, base station <NUM> indicates the contiguous cluster group allocation pattern of virtual cluster group numbers #<NUM> and #<NUM> to terminal <NUM> by the RIV-based allocation method.

In <FIG>, terminal <NUM> converts virtual cluster group numbers #<NUM> and #<NUM> to the actual cluster group numbers by cyclically shifting by -<NUM>, for example. This makes it possible to allocate the cluster groups distributed at, for example, both ends of the BWP (e.g., actual cluster groups #<NUM> and #<NUM>) to terminal <NUM> in <FIG>.

As described above, the conversion from the virtual allocation to the actual allocation in terminal <NUM> enables the non-contiguous allocation in the BWP (or system band), for example, thereby improving the frequency diversity gain.

For example, the OCB specification can be satisfied by the non-contiguous allocation at the both ends of the BWP, as illustrated in <FIG>, even when the cluster group to be allocated has a narrow bandwidth (when the allocated bandwidth is narrow). In addition, the indication of the contiguous virtual cluster group allocation pattern by the RIV-based allocation method reduces the signaling overhead.

Configuration Example <NUM> focuses on the fact that there is a small difference in the number of signaling bits between the RIV-based allocation method and the bitmap-based allocation method when the number of cluster groups per BWP (or system band) is small.

For example, the bitmap-based allocation method is applied to the cluster RA when the number of cluster groups per BWP is smaller than or equal to a threshold (e.g., <NUM>), and the RIV-based allocation method is applied to the cluster RA when the number of cluster groups per BWP is larger than the threshold, as illustrated in <FIG>.

In this manner, the signaling overhead can be reduced by applying the RIV-based allocation method when the number of cluster groups per BWP is large. When the number of cluster groups per BWP is small, in contrast, the application of the bitmap-based allocation method enables the allocation including non-contiguous cluster allocation patterns by the bitmap while preventing the increase in the signaling overhead, thereby improving the scheduling gain.

The exemplary configurations of the cluster RA have been described, thus far.

In the present embodiment, terminal <NUM> assigns a signal to a resource based on frequency resource allocation information indicating allocation of a plurality of cluster groups (e.g., the cluster RA) resulting from grouping a plurality of clusters into which a frequency band (e.g., system band or BWP) is divided, and allocation of interlaces (e.g., the interlace RA) in the clusters, and transmits the signal, as described above. Base station <NUM> then receives the signal transmitted from terminal <NUM> based on the cluster RA and the interlace RA for terminal <NUM>.

This allows base station <NUM> to perform flexible scheduling or frequency-multiplexing in units of cluster groups, for example, for terminals <NUM> even when terminals <NUM> have the system bandwidths (or BWPs) different from each other, or when the system bandwidth is <NUM> or more, for example.

Therefore, it is possible to appropriately transmit/receive signals in the operation in unlicensed bands (e.g., NR-U) according to the present embodiment.

Each embodiment of the present disclosure has been described, thus far.

Each of the methods described in the above embodiments may be used alone or in combination. In addition, the method to be used may be switched depending on the situation (e.g., communication environment and/or traffic). The communication environment may be represented by at least one of Reference Signal Received Power (RSRP), Received Signal Strength Indicators (RSSIs), Reference Signal Received Quality (RSRQ), and Signal-to-Interference plus Noise power Ratio (SINR), for example.

The uplink data channel (PUSCH) has been described in the above embodiments as an example of a transmission signal for which the frequency resource is allocated. However, the transmission signal is not limited to the PUSCH and may be another signal transmitted from terminal <NUM> (corresponding to a transmission apparatus) to base station <NUM> (corresponding to a reception apparatus), for example.

Additionally, the interlaces are not limited to be distributed in units of PRBs on the frequency domain, and may also be distributed in units of subcarrier groups of less subcarriers composing <NUM> PRB, for example. Further, the interlaces are not limited to be arranged at equal frequency intervals on the resources.

Furthermore, the number of clusters, the number of interlaces in the clusters, the number of cluster groups, the number of clusters in the cluster groups, and the number of subcarriers per interlace (or PRB) in a particular frequency band (e.g., system band) are not limited to those in the examples described in the above embodiments, and may include other values.

Although the operations in unlicensed bands have been described in the above embodiment, the present disclosure is not only for unlicensed bands. It can also be applied to licensed bands, and brings the similar effects.

The present disclosure can be realized by software, hardware, or software in cooperation with hardware. Each functional block used in the description of each embodiment described above can be partly or entirely realized by an LSI such as an integrated circuit, and each process described in the each embodiment may be controlled partly or entirely by the same LSI or a combination of LSIs. The LSI may be individually formed as chips, or one chip may be formed so as to include a part or all of the functional blocks. The LSI may include a data input and output coupled thereto. The LSI here may be referred to as an IC, a system LSI, a super LSI, or an ultra LSI depending on a difference in the degree of integration. However, the technique of implementing an integrated circuit is not limited to the LSI and may be realized by using a dedicated circuit, a general-purpose processor, or a special-purpose processor. In addition, a FPGA (Field Programmable Gate Array) that can be programmed after the manufacture of the LSI or a reconfigurable processor in which the connections and the settings of circuit cells disposed inside the LSI can be reconfigured may be used. The present disclosure can be realized as digital processing or analogue processing. If future integrated circuit technology replaces LSIs as a result of the advancement of semiconductor technology or other derivative technology, the functional blocks could be integrated using the future integrated circuit technology. Biotechnology can also be applied.

The present disclosure can be realized by any kind of apparatus, device or system having a function of communication, which is referred to as a communication apparatus. Some non-limiting examples of such a communication apparatus include a phone (e.g., cellular (cell) phone, smart phone), a tablet, a personal computer (PC) (e.g., laptop, desktop, netbook), a camera (e.g., digital still/video camera), a digital player (digital audio/video player), a wearable device (e.g., wearable camera, smart watch, tracking device), a game console, a digital book reader, a telehealth/telemedicine (remote health and medicine) device, and a vehicle providing communication functionality (e.g., automotive, airplane, ship), and various combinations thereof.

The communication apparatus is not limited to be portable or movable, and may also include any kind of apparatus, device or system being non-portable or stationary, such as a smart home device (e.g., an appliance, lighting, smart meter, control panel), a vending machine, and any other "things" in a network of an "Internet of Things (IoT).

The communication may include exchanging data through, for example, a cellular system, a radio LAN system, a satellite system, etc., and various combinations thereof.

The communication apparatus also may include an infrastructure facility, such as a base station, an access point, and any other apparatus, device or system that communicates with or controls apparatuses such as those in the above non-limiting examples.

This application is entitled to and claims the benefit of <CIT>.

Claim 1:
A transmission apparatus (<NUM>) for performing wireless communication in a frequency band, comprising:
circuitry (<NUM>), configured to assign a signal to a resource based on control information,
• the control information indicating allocation of a cluster group among a plurality of cluster groups resulting from grouping a plurality of clusters, into which the frequency band is divided, wherein each cluster group of the plurality of cluster groups includes a plurality of interlaces, and each of the plurality of interlaces includes at least two resource blocks, which are distributed at an interval over the frequency band, and
• the control information further indicating allocation of at least one of the plurality of interlaces in the plurality of clusters of the allocated cluster group,
wherein for indicating the allocation of the cluster group, the control information includes an allocation starting position in the frequency band and a number of the cluster groups to be consecutively allocated from the allocation starting position; and
wherein the resource is determined by combining the allocation of the at least one of the plurality of interlaces and the allocation of the cluster group; and
a transmitter (<NUM>) configured to transmit the signal in the assigned resource.