JP7499388B2 - Base station, communication method and integrated circuit - Google Patents

Description

The present disclosure relates to a terminal, a communication method, and an integrated circuit.

With the recent spread of services using mobile broadband, data traffic in mobile communications has been increasing exponentially, making it urgent to expand data transmission capacity for the future. In addition, the Internet of Things (IoT), in which all "things" will be connected via the Internet, is expected to develop dramatically in the future. To support the diversification of services brought about by IoT, not only data transmission capacity but also various other requirements such as low latency and communication area (coverage) will need to be dramatically improved. In light of this background, technological development and standardization of the 5th generation mobile communication system (5G), which will offer significantly improved performance and functionality compared to the 4th generation mobile communication system (4G), is underway.

One of the 4G radio access technologies (RATs) is LTE (Long Term Evolution)-Advanced, which has been standardized by 3GPP (3rd Generation Partnership Project). In standardizing 5G, 3GPP is developing a new radio access technology (NR: New RAT) that is not necessarily backward compatible with LTE-Advanced.

In the extension of LTE-Advanced, it is being considered to expand the operating bandwidth of existing LTE (1.4, 3, 5, 10, 15 and 20 MHz) to flexibly support various bandwidths (e.g., 1.8, 2.0, 2.2, 4.4, 4.6, 6.0, 6.2, 7.0, 7.8, 8.0, 11, 14, 18 and 19 MHz), thereby maximizing the use of frequency bands allocated to operators and improving system throughput (see, for example, Non-Patent Document 1).

NR is expected to support an operational bandwidth of several hundred MHz. On the other hand, terminal power consumption increases in proportion to the radio frequency (RF) bandwidth. For this reason, in NR, when a terminal receives downlink control signals in a bandwidth similar to the operational bandwidth of the network, as in LTE, the terminal power consumption increases. For this reason, in NR, it is being considered to allow terminals to receive downlink control signals in a narrower band than the operational bandwidth of the network, and to flexibly change the RF bandwidth of the terminal as necessary (for example, to expand the RF bandwidth of the terminal when transmitting and receiving data signals) (for example, see Non-Patent Documents 2 and 3).

One of the methods for expanding the bandwidth is Carrier Aggregation (CA) introduced in LTE-Advanced. CA is a method for expanding the bandwidth by combining multiple bands (component carriers) of the existing LTE operating bandwidth. Therefore, when applying CA to the above-mentioned system that can flexibly change the bandwidth, some frequency bandwidths (e.g., 1.8, 2.0, 2.2, 4.6, 6.2, 7.0, 14, and 19 MHz) cannot be used with the existing LTE operating bandwidth combination. In addition, CA that combines narrow-bandwidth component carriers requires transmission and scheduling of control signals for each component carrier, which increases the overhead of control signals and is not efficient. In addition, terminals must have CA capabilities even when the operating bandwidth is narrow. For example, in the case of 11 MHz, the terminal must have the ability to combine three component carriers, 5 MHz + 3 MHz + 3 MHz. This increases the complexity of the terminal.

As a method of expanding the band without using CA capabilities and mechanisms, a method of adding an extension band called a segment to the existing LTE band has been considered (see, for example, Non-Patent Document 4). With this method, the existing LTE band (also called Backward compatible carrier (BCC)) and the segment can be scheduled with a single downlink control signal, making it possible to reduce the overhead of the control signal. In addition, with this method, the terminal does not need to have CA capabilities even when the operating bandwidth is narrow, making it possible to reduce the complexity of the terminal. Therefore, in the above-mentioned system that flexibly supports various bandwidths, the method of adding a segment is more efficient than the CA mechanism.

RP-151890, "Motivation for new work item proposal on LTE bandwidth flexibility enhancements," Huawei, China Unicom, HiSilicon, RAN#70, December 2015. R1-1613218, "Way Forward on UE bandwidth adaptation in NR," MediaTek, Acer, AT&T, CHTTL, Ericsson, III, InterDigital, ITRI, NTT Docomo, Qualcomm, Samsung, Verizon, RAN1#87, November 2016. RAN1#85 chairman’s note R1-130786, "Way Forward on synchronized carrier and segment," Panasonic, KDDI, AT&T, Qualcomm, Motorola Mobility, New Postcom, Interdigital, RAN1#72,February 2013. 3GPP TS 36.213 V13.3.0, "Evolved Universal Terrestrial Radio Access (E-UTRA); Physical layer procedures (Release 13)," September 2016. 3GPP TS 36.211 V13.3.0, “Evolved Universal Terrestrial Radio Access (E-UTRA); Physical channels and modulation (Release 13),” September 2016.

In the above-mentioned wireless communication system that flexibly supports various bandwidths in LTE-Advanced and in the wireless communication system that enables flexible changes to the RF bandwidth of terminals in NR, when the method of adding segments is applied, detailed mechanisms must be considered, such as the method of determining the parameters required for operation with flexible bandwidths (e.g., the bandwidth after adding segments).

One aspect of the present disclosure contributes to providing a base station, a terminal, and a communication method that can appropriately determine parameters required for operation with flexible bandwidth.

A base station according to one aspect of the present disclosure includes a circuit for determining parameters for a second band consisting of the first band and a segment that is an additional band to the first band, and a transceiver for communicating with the terminal in the second band using the parameters.

A terminal according to one aspect of the present disclosure includes a circuit for determining parameters for a second band consisting of the first band and a segment that is an additional band to the first band, and a transceiver for communicating with a base station in the second band using the parameters.

A communication method according to one aspect of the present disclosure determines parameters for a second band consisting of the first band and a segment that is an additional band to the first band, and communicates with the terminal in the second band using the parameters.

A communication method according to one aspect of the present disclosure determines parameters for a second band consisting of the first band and a segment that is an additional band to the first band, and communicates with a base station in the second band using the parameters.

These comprehensive or specific aspects may be realized as a system, a method, an integrated circuit, a computer program, or a recording medium, or may be realized as any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium.

According to one aspect of the present disclosure, it is possible to appropriately determine the parameters required for operation with flexible bandwidth.

Further advantages and benefits of certain aspects of the present disclosure will become apparent from the specification and drawings. Such advantages and/or benefits may be provided by some of the embodiments and features described in the specification and drawings, respectively, but not necessarily all of them need be provided to obtain one or more identical features.

FIG. 1 is a block diagram showing a configuration of a base station according to a first embodiment; FIG. 1 is a block diagram showing a configuration of a terminal according to a first embodiment; FIG. 1 is a block diagram showing a configuration of a base station according to a first embodiment; FIG. 1 is a block diagram showing a configuration of a terminal according to a first embodiment; A diagram showing an example of RBG configuration FIG. 1 is a diagram showing a flow of a method for determining an RBG size according to the first embodiment. FIG. 1 is a diagram showing an example of a method for determining an RBG size according to the first embodiment; FIG. 13 is a diagram showing an example of a method for determining an RBG size according to a first modification of the first embodiment; FIG. 13 is a diagram showing an example of a method for determining an RBG size according to a second modification of the first embodiment; FIG. 1 is a diagram for explaining the problem of the second embodiment. FIG. 13 is a diagram showing an example of a method for determining an RBG size according to the second embodiment; A diagram showing an example of an RB grid between numerologies with different subcarrier spacing A diagram showing an example of an RB grid and RBG between numerologies with different subcarrier intervals. FIG. 13 is a diagram showing an example of a method for determining an RBG size according to the third embodiment; FIG. 13 is a diagram showing an example of a method for determining an RBG size according to the fourth embodiment; FIG. 13 is a diagram showing an example of RBG setting when a first band and a segment are discontinuous on the frequency axis; FIG. 13 is a diagram showing an example of a method for determining RBG according to the fifth embodiment. FIG. 23 shows an example of a method for determining RBG according to the sixth embodiment. FIG. 23 is a diagram showing an example of a method for determining a PRG according to the seventh embodiment; FIG. 23 is a diagram showing an example of a method for determining a PRG according to the eighth embodiment; FIG. 23 shows an example of a method for determining a CSI subband size according to the ninth embodiment. FIG. 23 shows an example of a method for determining a CSI subband size according to a tenth embodiment. FIG. 23 shows an example of a method for determining an SRS subband size according to an eleventh embodiment. FIG. 23 shows an example of a method for determining an SRS subband size according to a twelfth embodiment.

The following describes in detail the embodiments of the present disclosure with reference to the drawings.

In one aspect of the present disclosure, a method is described in which an extended band including a BCC and a segment is regarded as one virtual carrier, and parameters required for operation are determined for the virtual carrier. According to this method, the base station can schedule resource allocation for the extended band including the BCC and the segment after adding the segment with one downlink control signal. In addition, changes to the existing resource allocation mechanism can be kept to a minimum.

(Embodiment 1)
[Communication System Overview]
The communication system according to each embodiment of the present disclosure includes a base station 100 and a terminal 200.

FIG. 1 is a block diagram showing the configuration of a base station 100 according to each embodiment of the present disclosure. In the base station 100 shown in FIG. 1, the control unit 101 determines parameters (here, RBG size) for a second band (virtual carrier) consisting of a first band and a segment that is an additional band to the first band, and the transmission unit 113 (corresponding to a transceiver, including a signal allocation unit 111) uses the parameters to communicate with the terminal 200 in the second band.

FIG. 2 is a block diagram showing the configuration of a terminal 200 according to each embodiment of the present disclosure. In the terminal 200 shown in FIG. 2, the control unit 208 determines parameters (RBG size) for a second band (virtual carrier) consisting of a first band and a segment that is an additional band to the first band, and the receiving unit 202 (corresponding to a transceiver, including an extraction unit 204) uses the parameters to communicate with the base station 100 in the second band.

In the following, the "BCC" or the "First RF band" that is the band required for terminal 200 to receive a downlink control signal (e.g., DCI (Downlink Control Information)) is defined as the "first band."

In the following, the extended band including the BCC and the segment after adding the segment to the first band is defined as the "Virtual carrier" or "second band."

[Base station configuration]
Fig. 3 is a block diagram showing a configuration of a base station 100 according to the first embodiment of the present disclosure. In Fig. 3, the base station 100 includes a control unit 101, a data generating unit 102, an encoding unit 103, a modulation unit 104, a higher-level control signal generating unit 105, an encoding unit 106, a modulation unit 107, a downlink control signal generating unit 108, an encoding unit 109, a modulation unit 110, a signal allocation unit 111, an IFFT (Inverse Fast Fourier Transform) unit 112, a transmission unit 113, an antenna 114, a reception unit 115, an FFT (Fast Fourier Transform) unit 116, an extraction unit 117, a CSI (Channel State Information) demodulation unit 118, and an SRS (Sounding Reference Signal) measurement unit 119.

The control unit 101 determines the RBG (Resource Block Group) size for the virtual carrier (second band). At this time, the control unit 101 outputs information indicating the RBG size for the determined virtual carrier to the signal allocation unit 111. Note that the control unit 101 may output information indicating the RBG size for the determined virtual carrier to the higher-level control signal generation unit 105.

The control unit 101 also determines information related to CSI feedback or SRS, and outputs the determined information to the higher control signal generation unit 105 and the extraction unit 117 (details will be described later in embodiments 9 to 12). Furthermore, when the RBG (RBG size or RBG division) for the virtual carrier can be changed, the control unit 101 outputs information related to the change in setting to the higher control signal generation unit 105 (details will be described later in embodiments 4 and 6).

The control unit 101 also determines the radio resource allocation for downlink data for the terminal 200, for example, using the determined RBG, and outputs downlink resource allocation information instructing the resource allocation for the downlink data to the downlink control signal generation unit 108 and the signal allocation unit 111.

The data generation unit 102 generates downlink data for the terminal 200 and outputs it to the encoding unit 103.

The encoding unit 103 performs error correction encoding on the downlink data input from the data generation unit 102, and outputs the encoded data signal to the modulation unit 104.

The modulation unit 104 modulates the data signal input from the encoding unit 103 and outputs the data modulated signal to the signal allocation unit 111.

The higher-level control signal generating unit 105 generates a control information bit string using information input from the control unit 101, and outputs the generated control information bit string to the encoding unit 106. The higher-level control signal generating unit 105 also generates a control information bit string using information (e.g., bandwidth) related to the first band (BCC or First RF band) and information (e.g., bandwidth) related to the segment (additional band), and outputs the generated control information bit string to the encoding unit 106.

The encoding unit 106 performs error correction encoding on the control information bit sequence input from the higher-level control signal generating unit 105, and outputs the encoded control signal to the modulation unit 107.

The modulation unit 107 modulates the control signal input from the encoding unit 106 and outputs the modulated control signal to the signal allocation unit 111.

The downlink control signal generating unit 108 generates a control information bit string using information indicating the RBG size carried by the virtual carrier input from the control unit 101 and downlink resource allocation information, and outputs the generated control information bit string to the encoding unit 109. Note that since control information may be transmitted to multiple terminals, the downlink control signal generating unit 108 may generate a bit string by including the terminal ID of each terminal in the control information for each terminal.

The encoding unit 109 performs error correction encoding on the control information bit sequence input from the downlink control signal generating unit 108, and outputs the encoded control signal to the modulation unit 110.

The modulation unit 110 modulates the control signal input from the encoding unit 109 and outputs the modulated control signal to the signal allocation unit 111.

The signal allocation unit 111 maps the data signal input from the modulation unit 104 to radio resources based on the information related to RBG or the downlink resource allocation information input from the control unit 101. The signal allocation unit 111 also maps the control signal input from the modulation unit 107 or the modulation unit 110 to radio resources. The signal allocation unit 111 outputs the downlink signal to which the signal has been mapped to the IFFT unit 112.

The IFFT unit 112 performs transmission waveform generation processing such as OFDM (Orthogonal Frequency Division Multiplexing) on the signal input from the signal allocation unit 111. In the case of OFDM transmission that adds a CP (Cyclic Prefix), the IFFT unit 112 adds a CP (not shown). The IFFT unit 112 outputs the generated transmission waveform to the transmission unit 113.

The transmitting unit 113 performs RF (Radio Frequency) processing such as D/A (Digital-to-Analog) conversion and up-conversion on the signal input from the IFFT unit 112, and transmits the wireless signal to the terminal 200 via the antenna 114.

The receiver 115 performs RF processing such as down-conversion or A/D (Analog-to-Digital) conversion on the signal waveform of the CSI feedback signal or SRS from the terminal 200 received via the antenna 114, and outputs the resulting received signal to the FFT unit 116.

The FFT unit 116 performs FFT processing on the received signal input from the receiving unit 115 to convert the time domain signal into a frequency domain signal. The FFT unit 116 outputs the frequency domain signal obtained by the FFT processing to the extraction unit 117.

The extraction unit 117 extracts the radio resource on which the CSI feedback signal or SRS is transmitted from the signal input from the FFT unit 116 based on the information received from the control unit 101 (information on CSI feedback or information on SRS), and outputs the extracted radio resource components (CSI feedback signal or SRS signal) to the CSI demodulation unit 118 and the SRS measurement unit 119, respectively.

The CSI demodulation unit 118 demodulates the CSI feedback signal input from the extraction unit 117 and outputs the demodulated information to the control unit 101. The CSI feedback is used, for example, in the control unit 101 to control downlink allocation.

The SRS measurement unit 119 measures the uplink channel quality using the SRS signal input from the extraction unit 117, and outputs the measured information to the control unit 101. The measured information is used, for example, in the control unit 101 to control the uplink allocation (not shown).

[Device configuration]
Fig. 4 is a block diagram showing a configuration of terminal 200 according to embodiment 1 of the present disclosure. In Fig. 4, terminal 200 includes antenna 201, receiving section 202, FFT section 203, extraction section 204, downlink control signal demodulation section 205, higher-level control signal demodulation section 206, downlink data signal demodulation section 207, control section 208, CSI generation section 209, encoding section 210, modulation section 211, SRS generation section 212, signal allocation section 213, IFFT section 214, and transmission section 215.

The receiver 202 performs RF processing such as down-conversion or A/D (Analog-to-Digital) conversion on the signal waveform of the downlink signal (data signal and control signal) from the base station 100 received via the antenna 201, and outputs the resulting received signal (baseband signal) to the FFT unit 203.

The FFT unit 203 performs FFT processing on the signal (time domain signal) input from the receiving unit 202 to convert the time domain signal into a frequency domain signal. The FFT unit 203 outputs the frequency domain signal obtained by the FFT processing to the extraction unit 204.

Based on the control information input from the control unit 208, the extraction unit 204 extracts a downlink control signal from the signal input from the FFT unit 203 and outputs it to the downlink control signal demodulation unit 205. Based on the control information input from the control unit 208, the extraction unit 204 also extracts a high-order control signal and a downlink data signal, outputs the high-order control signal to the high-order control signal demodulation unit 206, and outputs the downlink data signal to the downlink data signal demodulation unit 207.

The downlink control signal demodulation unit 205 performs blind decoding on the downlink control signal input from the extraction unit 204, and if it determines that the control signal is addressed to the device itself, it demodulates the control signal and outputs it to the control unit 208.

The higher-order control signal demodulation unit 206 demodulates the higher-order control signal input from the extraction unit 204 and outputs the demodulated higher-order control signal to the control unit 208.

The downstream data signal demodulation unit 207 demodulates the downstream data signal input from the extraction unit 204 to obtain a demodulated signal.

The control unit 208 calculates the radio resource allocation for the downlink data signal based on the downlink resource allocation information indicated in the control signal input from the downlink control signal demodulation unit 205, and outputs information indicating the calculated radio resource allocation to the extraction unit 204.

The control unit 208 also sets an RBG (RBG size or RBG division) for the virtual carrier (second band) using a method described later based on the downlink control signal input from the downlink control signal demodulation unit 205 or the higher-order control signal input from the higher-order control signal demodulation unit 206. Then, the control unit 208 outputs information related to the set RBG to the extraction unit 204.

The control unit 208 also sets radio resources for CSI feedback or SRS based on the downlink control signal input from the downlink control signal demodulation unit 205 or the higher-level control signal input from the higher-level control signal demodulation unit 206, and outputs information about the set CSI feedback or SRS to the signal allocation unit 213 (details will be described later in embodiments 9 to 12).

The CSI generating unit 209 generates a CSI feedback bit sequence using the measurement results of the downlink channel quality measured in the terminal 200, and outputs the CSI feedback bit sequence to the encoding unit 210.

The encoding unit 210 performs error correction encoding on the CSI feedback bit sequence input from the CSI generation unit 209, and outputs the encoded CSI signal to the modulation unit 211.

The modulation unit 211 modulates the CSI signal input from the encoding unit 210 and outputs the modulated CSI signal to the signal allocation unit 213.

The SRS generation unit 212 generates an SRS sequence and outputs it to the signal allocation unit 213.

The signal allocation unit 213 maps the CSI signal input from the modulation unit 211 and the SRS sequence input from the SRS generation unit 212 to radio resources instructed by the control unit 208. The signal allocation unit 213 outputs the uplink signal to which the signal has been mapped to the IFFT unit 214.

The IFFT unit 214 performs transmission waveform generation processing such as OFDM on the signal input from the signal allocation unit 213. In the case of OFDM transmission in which a CP (Cyclic Prefix) is added, the IFFT unit 214 adds a CP (not shown). Alternatively, in the case where the IFFT unit 214 generates a single carrier waveform, a DFT (Discrete Fourier Transform) unit may be added before the signal allocation unit 213 (not shown). The IFFT unit 214 outputs the generated transmission waveform to the transmission unit 215.

The transmitter 215 performs RF (radio frequency) processing such as D/A (digital-to-analog) conversion and up-conversion on the signal input from the IFFT unit 214, and transmits the wireless signal to the base station 100 via the antenna 201.

[Operations of base station 100 and terminal 200]
The operations of base station 100 and terminal 200 having the above configuration will now be described in detail.

In this embodiment, in a wireless communication system that flexibly supports various bandwidths in the above-mentioned LTE-Advanced, or in a wireless communication system that enables flexible change of the RF bandwidth of the terminal 200 in NR, the base station 100 and the terminal 200 determine parameters required for communication between the base station 100 and the terminal 200 for one "Virtual carrier" (second band), which is an extended band including the first band and the segment after adding a segment to the first band.

LTE-Advanced and NR use OFDM or Single-Carrier Frequency Division Multiple Access (SC-FDMA) for signal waveforms. These signal waveforms use different subcarriers for each terminal, enabling multiple connections between the base station and multiple terminals.

A resource block (RB) is the smallest unit of radio resource allocation, and in LTE-Advanced or NR, it is composed of 12 subcarriers regardless of the subcarrier spacing. However, an RB is not limited to 12 subcarriers and may be composed of other numbers of subcarriers.

In LTE-Advanced, one method of allocating RBs to terminals for the downlink data channel (PDSCH: Physical Downlink Shared Channel) is to use a unit of a group of radio resources called a resource block group (RBG). As shown in Figure 5, an RBG is composed of multiple consecutive RBs (two RBs in the example of Figure 5). In LTE-Advanced, the number of resource blocks (RBG size) P included in an RBG is set according to the system bandwidth (see, for example, Non-Patent Document 5). For example, the base station may notify the terminal of the PDSCH resource allocation to a terminal by using a bitmap in RBG units in a downlink control signal (DCI). In this case, the more RBGs there are, the more bits there are in the downlink control signal.

In this embodiment, the base station 100 and the terminal 200 determine the size of the RBG, which is a parameter applied to PDSCH resource allocation, as a parameter for the virtual carrier. Specifically, the base station 100 and the terminal 200 determine the RBG size for the virtual carrier based on the bandwidth of the virtual carrier (i.e., the sum of the bandwidth of the first band and the segment).

Figure 6 shows a flow diagram of the RBG size determination process according to this embodiment.

The base station 100 notifies the terminal 200 of a synchronization signal (PSS (Primary Synchronization Signal)/SSS (Secondary Synchronization Signal)) or system information (MIB (Master Information Block)/SIB (System Information Block)) in the first band (ST101).

The terminal 200 uses the first band to acquire system information and executes a random access procedure or RRC connection control with the base station 100 (ST102).

For example, the base station 100 may notify the terminal 200 of information (e.g., bandwidth) related to the first band using the above system information (e.g., MIB). The base station 100 may also notify the terminal 200 of information (e.g., bandwidth) related to a segment (additional band) using the above system information (e.g., SIB) or a terminal-specific RRC (Radio Resource Control) signal. Note that there may be multiple segments.

The information on the first band and the information on the segment may be notified from the base station 100 to the terminal 200 by a method other than the above. For example, the base station 100 may notify the terminal 200 of the information on the segment using the MIB. At this time, the MIB may be notified to the terminal 200 using the first band, or may be notified to the terminal 200 using the segment. The base station 100 may also notify the terminal 200 of the information on the virtual carrier (e.g., the total bandwidth of the first band and the segment). If the first band and the segment are continuous on the frequency axis, the base station 100 may notify the terminal 200 of the information on the virtual carrier (e.g., the total bandwidth), and if the first band and the segment are discontinuous on the frequency axis, the base station 100 may notify the terminal 200 of the information on the segment (e.g., the bandwidth) using system information (e.g., SIB) or a terminal-specific RRC signal.

The base station 100 may use MAC signaling, an RRC signal, or a downlink control signal (DCI: Downlink Control Information) to notify the terminal 200 of segment configuration (starting and ending use of a segment).

Next, the base station 100 calculates the bandwidth of the virtual carrier, which is an extended band including the first band and the segment, based on the information (bandwidth) related to the first band and the information (bandwidth) related to the segment (additional band). Then, the base station 100 determines the RBG size for the virtual carrier based on the calculated bandwidth of the virtual carrier (ST103). The method of determining the RBG size of the virtual carrier will be described in detail later.

Furthermore, like base station 100 (ST101), terminal 200 calculates the bandwidth of the virtual carrier (i.e., the sum of the bandwidth of the first band and the segment) using the information (bandwidth) about the first band and the information (bandwidth) about the segment notified from base station 100 in ST101. Then, terminal 200 determines the RBG size for the virtual carrier based on the calculated bandwidth of the virtual carrier (ST104).

Then, the base station 100 allocates resources for downlink data (PDSCH) in the virtual carrier to the terminal 200 using the determined RBG size, and transmits downlink resource allocation information and the downlink data (ST105). The terminal 200 identifies the allocated downlink resources based on the determined RBG size, and receives the downlink data.

Figures 7 and 8 show an example of a method for determining the RBG size according to this embodiment.

In the following, as an example, the relationship between the system bandwidth and the RBG size is the same as that of LTE. Specifically, when the system bandwidth is 10 RB or less, the RBG size P = 1; when the system bandwidth is 11 RB to 26 RB, the RBG size P = 2; when the system bandwidth is 27 RB to 63 RB, the RBG size P = 3; and when the system bandwidth is 64 RB to 110 RB, the RBG size P = 4 (see, for example, Non-Patent Document 5). However, the relationship between the system bandwidth and the RBG size is not limited to the same relationship as that of LTE. In addition, in LTE, the RBG size is only considered up to 20 MHz (110 RB), but in NR, the application of a bandwidth wider than 20 MHz (for example, 80 MHz) is also considered, so when the system bandwidth is wider than 20 MHz, an RBG size larger than P = 4 may be used.

The base station 100 and the terminal 200 determine the RBG size of the virtual carrier based on the bandwidth of the virtual carrier (second band) that includes the first band and the segment, rather than the bandwidth of each of the first band and the segment assigned to the terminal 200.

Figure 7 shows an example where the first band is 5 MHz (25 RB) and the segment is 3 MHz (15 RB). When data is transmitted and received individually in the first band or segment shown in Figure 7, the RBG size of the first band and segment is P=2, which corresponds to 25 RB and 15 RB, respectively. On the other hand, the bandwidth of the virtual carrier shown in Figure 7 is 8 MHz (40 RB), so when data is transmitted and received using the virtual carrier, the RBG size is P=3, which corresponds to 40 RB.

Figure 8 shows an example where the first band is 5 MHz (25 RB) and the segment is 1.4 MHz (6 RB). When individual data is transmitted and received in the first band or segment shown in Figure 8, the RBG size of the first band is P=2 corresponding to 25 RB, and the RBG size of the segment is P=1 corresponding to 6 RB. On the other hand, the bandwidth of the virtual carrier shown in Figure 8 is 6.4 MHz (31 RB), so when data is transmitted and received using the virtual carrier, the RBG size is P=3 corresponding to 31 RB.

In other words, in Figures 7 and 8, the RBG size is larger when the RBG size is determined based on a virtual carrier including the first band and segment, compared to when the RBG size is determined based on the individual bandwidths of the first band and segment. Therefore, by determining the RBG size on a virtual carrier basis in all bandwidths (8 MHz or 6.4 MHz) of the first band and segments shown in Figures 7 and 8, the total number of RBGs set in the virtual carrier can be reduced.

In this manner, according to the present embodiment, the base station 100 and the terminal 200 determine the RBG size for the virtual carrier, with the virtual carrier including the first band and the segment as one unit. This allows the number of RBGs in the virtual carrier to be reduced, so that the number of bits required for resource allocation in the downlink control signal (DCI) can be reduced compared to the case where the RBG size is applied when the first band and the segment are used individually, and the overhead of resource allocation can be reduced.

In other words, according to this embodiment, even if a method of adding segments is applied in a wireless communication system that flexibly supports various bandwidths in LTE-Advanced or a wireless communication system that enables flexible changes to the RF bandwidth of a terminal in NR, it is possible to appropriately determine parameters (here, RBG size) required for operation in a flexible bandwidth (e.g., virtual carrier).

(First Modification of First Embodiment)
In the first modification, the base station 100 and the terminal 200 calculate the next largest standard bandwidth after the bandwidth of the first band, and determine the RBG size for the virtual carrier (second band).

Here, the standard bandwidths in LTE-Advanced are 1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz, and 20 MHz. Note that the standard bandwidths are not limited to the above values, and other standard bandwidths may be specified.

For example, in FIG. 9, the next largest standard bandwidth after the bandwidth of the first band (10 MHz: 50 RB) is 15 MHz (75 RB). Therefore, the base station 100 and the terminal 200 determine the RBG size for the virtual carrier including the first band and the segment of 10 MHz to be P=4, which corresponds to 15 MHz.

As a result, even if, for example, information (bandwidth) related to the first band and information (bandwidth) related to the segment are notified separately to the terminal 200, the terminal 200 can determine the RBG size of the virtual carrier from the bandwidth of the first band. In other words, according to the first variant example, the method of determining the RBG size can be simplified.

(Second Modification of First Embodiment)
In the second modification, the base station 100 and the terminal 200 calculate a standard bandwidth having the smallest bandwidth among standard bandwidths larger than the bandwidth of the virtual carrier (second band), and determine the RBG size for the virtual carrier.

For example, the standard bandwidth with the smallest bandwidth among the standard bandwidths larger than the virtual carrier bandwidth (11.4 MHz (56 RB)) shown in FIG. 9 is 15 MHz (75 RB). Therefore, the base station 100 and the terminal 200 determine the RBG size for the virtual carrier to be P=4, which corresponds to 15 MHz.

As a result, the base station 100 and the terminal 200 can simplify the method of determining the RBG size by determining the RBG size for the virtual carrier in the same manner as the standard bandwidth that is close to the bandwidth of the virtual carrier.

In addition, according to the first and second variants of the first embodiment, by setting the bandwidth for resource allocation to the same as the standard bandwidth used when determining the RBG, the resource allocation region in the DCI can be made the same as the standard bandwidth, thereby simplifying the decoding of the DCI in the terminal 200.

(Embodiment 2)
In embodiment 1, a case is described in which the RBG size of a virtual carrier is determined based on the bandwidth of the virtual carrier (second band), whereas in this embodiment, a case is described in which the RBG size of a virtual carrier is determined based on the RBG size of a first band (e.g., BCC).

Here, if a terminal that transmits and receives data using the first band and a terminal that transmits and receives data using a virtual carrier are mixed within the same resource, the resource may not be used efficiently.

Figure 10 shows an example in which the first band is 5 MHz (25 RB) and the segment is 3 MHz (15 RB). Note that in Figure 10, the RBG size is determined according to the system bandwidth, as in the first embodiment.

In FIG. 10, when individual data is transmitted and received using the first band or segment, the RBG size of the first band and segment is P=2. On the other hand, since the bandwidth of the virtual carrier is 8 MHz (40 RB), when data is transmitted and received using the virtual carrier, the RBG size of the virtual carrier is P=3.

In this case, as shown in FIG. 10, when a terminal (called "terminal #1") that transmits and receives data using the first band and a terminal (called "terminal #2") that transmits and receives data using a virtual carrier are mixed, if RBG #2 (RB #3, RB #4) is assigned to terminal #1, RBG #1 (RB #1-#3) and RBG #2 (RB #4-#6), which include RB #3 and #4, cannot be assigned to terminal #2. In other words, in FIG. 10, one RBG assigned to terminal #1 is set across resources equivalent to two RBGs for terminal #2, which reduces the efficiency of resource allocation to terminal #2.

Therefore, in this embodiment, the RBG size for the virtual carrier is determined taking into account the RBG size of the first band.

The base station and terminal according to this embodiment have the same basic configuration as the base station 100 and terminal 200 according to embodiment 1, so they will be described with reference to Figures 3 and 4.

The method by which the base station 100 notifies the terminal 200 of the information (bandwidth) related to the first band and the information (bandwidth) related to the segment (additional band), and the method by which the base station 100 sets the segment to the terminal 200 (starting and ending use) are the same as in embodiment 1, so the description thereof will be omitted here.

Base station 100 according to this embodiment calculates the bandwidth of the virtual carrier (i.e., the sum of the bandwidth of the first band and the segment) based on information (bandwidth) about the first band and information (bandwidth) about the segment (additional band). Furthermore, terminal 200 calculates the bandwidth of the virtual carrier (second band) based on information (bandwidth) about the first band and information (bandwidth) about the segment notified by base station 100.

In addition, in this embodiment, the base station 100 and the terminal 200 determine the RBG size to be set for the virtual carrier to be X times (where X is an integer equal to or greater than 2) the RBG size set based on the bandwidth of the first band. Note that information regarding X may be notified from the base station 100 to the terminal 200, or may be a value determined by the standard.

Figure 11 shows an example of a method for determining the RBG size according to this embodiment.

Figure 11 shows an example where the first band is 5 MHz (25 RB), the segment is 3 MHz (15 RB), and the bandwidth of the virtual carrier is 8 MHz (40 RB). When transmitting and receiving individual data in the first band or segment shown in Figure 11, the RBG size of the first band and the segment is P = 2, which corresponds to 25 RB and 15 RB, respectively.

In FIG. 11, X=2. Therefore, the RBG size when transmitting and receiving data using the virtual carrier shown in FIG. 11 is P=4, which is X times the RBG size P=2 set based on the bandwidth of the first band. In this way, the RBG boundary (delimiter) set for the virtual carrier matches the RBG boundary set based on the bandwidth of the first band. This allows the base station 100 to efficiently allocate resources to the terminal 200 that transmits and receives data using the virtual carrier.

For example, in FIG. 11, when a terminal that transmits and receives data using the first band and a terminal that transmits and receives data using a virtual carrier are mixed in the same resource, RBG#2 (RB#3, RB#4) is assigned to the terminal that transmits and receives data using the first band. In this case, base station 100 cannot assign RBG#1 (RB#1-#4) including RB#3 and #4 to the terminal that transmits and receives data using a virtual carrier. In other words, in the example shown in FIG. 10, there are two RBGs that are not assigned to the terminal that transmits and receives data using the virtual carrier due to one RBG assigned to the terminal that transmits and receives data using the first band, whereas in this embodiment (FIG. 11), only one RBG is required.

In this manner, in this embodiment, by setting the RBG size for the virtual carrier to an integer multiple of the RBG size set based on the bandwidth of the first band, it is possible to prevent the RBG assigned to a terminal that transmits and receives data using the first band from being set across resources equivalent to multiple RBGs for a terminal that transmits and receives data using the virtual carrier. This makes it possible to efficiently multiplex a terminal that transmits and receives data using the first band and a terminal that transmits and receives data using the virtual carrier.

In addition, according to this embodiment, an RBG size larger than the RBG size of the first band can be set for the virtual carrier. As a result, as in embodiment 1, when using a virtual carrier, the number of RBGs in the virtual carrier can be reduced compared to when the RBG size of the first band is applied as is, so that the number of bits required for resource allocation in the downlink control signal (DCI) can be reduced, and the overhead of resource allocation can be reduced.

(Embodiment 3)
In NR, mixed numerology, which mixes signal waveforms with different subcarrier intervals and the like within the same band, is being considered as a method for accommodating terminals of services with different requirements. In addition, in NR, it is being considered that RBs be composed of 12 subcarriers regardless of the subcarrier interval. In addition, in 3GPP, when FDM is used for numerology with different subcarrier intervals, it has been agreed that the RB grid for each subcarrier interval should be a nested structure as shown in FIG. 12. Note that the allocation of RB numbers shown in FIG. 12 is an example and is not limited to this.

Figure 13 also shows an example of an RB grid when multiplexing terminals with subcarrier spacings of 15 kHz, 30 kHz, and 60 kHz. As shown in Figure 13, when terminals with different subcarrier spacings are mixed, if the RBG size is a power of 2, the RBG boundaries (separators) and the RB grid boundaries can be aligned between numerologies with different subcarrier spacings, allowing for efficient use of resources.

Therefore, in this embodiment, the RBG size for the virtual carrier is also set to a power of 2.

The base station and terminal according to this embodiment have the same basic configuration as the base station 100 and terminal 200 according to embodiment 1, so they will be described with reference to Figures 3 and 4.

The method by which the base station 100 notifies the terminal 200 of the information (bandwidth) related to the first band and the information (bandwidth) related to the segment (additional band), and the method by which the base station 100 sets the segment to the terminal 200 (starting and ending use) are the same as in embodiment 1, so the description thereof will be omitted here.

Base station 100 according to this embodiment calculates the bandwidth of the virtual carrier (i.e., the sum of the bandwidths of the first band and the segment) based on information (bandwidth) about the first band and information (bandwidth) about the segment (additional band). Furthermore, terminal 200 calculates the bandwidth of the virtual carrier (second band) based on information (bandwidth) about the first band and information (bandwidth) about the segment notified by base station 100.

In this embodiment, the base station 100 and the terminal 200 determine a power of 2 as the RBG size to be set in the virtual carrier. Note that information on the RBG size (e.g., a power of 2: the value of ⁿ in 2n) may be notified from the base station 100 to the terminal 200, or may be a value determined by the standard. Also, similar to the first embodiment, the RBG size (e.g., a power of 2: the value of n in ²ⁿ ) may be calculated from the bandwidth of the virtual carrier.

Figure 14 shows an example of a method for determining the RBG size according to this embodiment.

Figure 14 shows an example where the RBG size P of the first band with 15 kHz subcarrier spacing is P = 2, and the RBG size P of the virtual carrier with 30 kHz subcarrier spacing is 2 = 2. That is, in Figure 14, the RBG size of the virtual carrier is 1st power of 2. In this way, the RBG boundary (delimiter) set for the virtual carrier matches the RBG boundary set based on the bandwidth of the first band. This allows the base station 100 to efficiently allocate resources to the terminal 200 that transmits and receives data using the virtual carrier.

For example, in FIG. 14, when a terminal that transmits and receives data using the first band and a terminal that transmits and receives data using a virtual carrier are mixed in the same resources, RBG#2 (RB#3, RB#4) is assigned to the terminal that transmits and receives data using the first band. In this case, base station 100 cannot assign RBG#1 (RB#1, #2), which includes the same resources as RB#3 and #4 at 15 kHz subcarrier spacing, to the terminal that transmits and receives data using the virtual carrier. In other words, as shown in FIG. 14, only one RBG is assigned to the terminal that transmits and receives data using the virtual carrier.

In this way, in this embodiment, by setting the RBG size for the virtual carrier to a power of 2, even when terminals with different subcarrier spacing are present, the RBG boundaries can be aligned between terminals, allowing multiple terminals with different subcarrier spacing to be multiplexed efficiently.

That is, according to this embodiment, for example, in a wireless communication system that flexibly supports various bandwidths in LTE-Advanced, or in a wireless communication system that enables flexible change of the RF bandwidth of a terminal in NR, even when terminals with different subcarrier spacings are mixed, it is possible to appropriately determine the parameters (here, RBG size) required for operation in a flexible bandwidth (e.g., virtual carrier).

(Embodiment 4)
The base station and terminal according to this embodiment have a common basic configuration with base station 100 and terminal 200 according to the first embodiment, and therefore will be described with reference to FIGS.

The method by which the base station 100 notifies the terminal 200 of the information (bandwidth) related to the first band and the information (bandwidth) related to the segment (additional band), and the method by which the base station 100 sets the segment to the terminal 200 (starting and ending use) are the same as in embodiment 1, so the description thereof will be omitted here.

In this embodiment, we will explain the case where the RBG size for the virtual carrier (second band) is adaptively changed by signaling from the base station 100 to the terminal 200.

The control unit 101 of the base station 100 variably sets the RBG size for the virtual carrier depending on, for example, the communication status of the terminal 200. For example, when the base station 100 needs to multiplex a terminal that transmits and receives data using the first band and a terminal that transmits and receives data using the virtual carrier, the base station 100 determines the RBG size of the virtual carrier to be the same as the first band, an integer multiple of the first band, or a power of 2 (see, for example, embodiments 2 and 3). On the other hand, when the base station 100 does not need to multiplex a terminal that transmits and receives data using the first band, the base station 100 may determine the RBG size of the virtual carrier to a value other than an integer multiple (or the same) of the first band.

Then, the base station 100 notifies the terminal 200 of information regarding the RBG size for the virtual carrier (information regarding the setting change) using a higher control signal (e.g., system information (MIB or SIB) or an RRC signal).

The terminal 200 receives an upper control signal notified from the base station 100, and determines the RBG size for the virtual carrier based on the received upper control signal.

Figure 15 shows an example of a method for determining the RBG size according to the present embodiment. Figure 15 shows an example in which the RBG size of a virtual carrier can be set to either P=3 or P=4.

For example, in FIG. 15, when there is a mixture of terminals that transmit and receive using a first band with RBG size P=2 (see, for example, FIG. 10) and terminals that transmit and receive using a virtual carrier, base station 100 may notify terminals that transmit and receive using a virtual carrier of an RBG size of P=4 (or 2 to the power of 2), which is twice the RBG size P=2, as shown in the lower diagram of FIG. 15. This allows base station 100 to efficiently multiplex terminals that transmit and receive data using the first band and terminals that transmit and receive data using a virtual carrier, as in the second and third embodiments.

On the other hand, if there is no terminal that transmits and receives using the first band multiplexed with a terminal that transmits and receives using the virtual carrier, the base station 100 may notify the terminal that transmits and receives using the virtual carrier of RBG size P=3. As a result, for example, as in embodiment 1 (see FIG. 7), the RBG size is determined according to the bandwidth of the virtual carrier, and resource allocation can be flexibly performed while reducing the overhead of resource allocation.

In this way, according to this embodiment, the RBG size set in the virtual carrier is variable, and the RBG size is notified from the base station 100 to the terminal 200 by signaling (e.g., system information (MIB, SIB) or an RRC signal). This makes it possible to adaptively change the RBG size of the virtual carrier for the terminal 200 depending on, for example, whether multiplexing is required between a terminal that transmits and receives data using the first band and a terminal that transmits and receives data using the virtual carrier.

In addition, even if the RBG size is notified by system information (e.g., MIB or SIB), the terminal 200 may reconfigure the RBG size by an RRC signal.

Alternatively, when the RBG size is notified by an RRC signal, the terminal 200 may use the default RBG size until the terminal 200 receives the RRC signal. The default RBG size may be notified by system information or may be determined in the same manner as in the first to third embodiments.

(Embodiment 5)
In this embodiment, a method for determining RBs constituting an RBG, which is a parameter applied to resource allocation of a downlink data channel (PDSCH), will be described.

The base station and terminal according to this embodiment have the same basic configuration as the base station 100 and terminal 200 according to embodiment 1, so they will be described with reference to Figures 3 and 4.

The method by which the base station 100 notifies the terminal 200 of the information (bandwidth) related to the first band and the information (bandwidth) related to the segment (additional band), and the method by which the base station 100 sets the segment to the terminal 200 (starting and ending use) are the same as those in embodiment 1, so the description thereof will be omitted here. Also, the method of determining the RBG size may use any of the methods in embodiments 1 to 4.

In addition, when determining the RBG size by regarding the band including the first band and the segment as one virtual carrier (second band) as described in the above embodiments 1 to 4, there is a possibility that an RBG (RBG#9 in FIG. 16) including both the RB of the first band and the RB of the segment is configured as shown in FIG. 16. In this case, as shown in FIG. 16, if the first band and the segment are discontinuous on the frequency axis (if there is a gap on the frequency axis), multiple RBs with different channel conditions will be treated as one RBG (RBG#9). This is expected to have a negative impact on the scheduling, precoding settings, channel estimation accuracy, etc. for the RBG.

Therefore, in this embodiment, a case will be described in which the RBs constituting one RBG are composed of either the RBs of the first band or the RBs of a segment. In other words, in this embodiment, the base station 100 and the terminal 200 set the RBG so that the boundary (delimiter) of the RBG set in the virtual carrier coincides with the boundary between the first band and the segment included in the virtual carrier.

Figure 17 shows an example of a method for determining RBG according to this embodiment. In Figure 17, the RBG size is P=3.

In FIG. 17, the first band and the segments are discontinuous on the frequency axis. Also, in FIG. 17, RBG#1-#9 are composed of RBs (RB#1-RB#25) in the first band, and RBG#10-#14 are composed of RBs (RB#1-RB#15) in the segments.

As shown in FIG. 17, near the boundary between the first band and the segment in the virtual carrier, RBG#9 is formed by one RB#25 of the first band, and RBG#10 is formed by three RB#1 to #3 of the segment. That is, in FIG. 17, the RBG boundary at least coincides with the boundary between the first band and the segment. In other words, in FIG. 17, there is no RBG formed by resource blocks of both the first band and the segment that are discontinuous on the frequency axis. As a result, the RBs in each RBG shown in FIG. 17 are continuous on the frequency axis, so the channel conditions are similar.

Therefore, in this embodiment, even if the first band and the segment are discontinuous on the frequency axis, it is possible to suppress the effects of gaps on the frequency axis on scheduling for the RBG set in the virtual carrier, precoding settings, channel estimation accuracy, etc.

(Embodiment 6)
In this embodiment, a method for determining RBs constituting an RBG, which is a parameter applied to resource allocation of a downlink data channel (PDSCH), will be described.

The effect of the gap on the frequency axis described in embodiment 5 occurs when the first band and the segment are discontinuous on the frequency axis.

On the other hand, when the first band and the segment are continuous on the frequency axis, it is possible that processing can be simplified and the number of RBGs can be reduced by configuring the RBG without considering the boundary between the first band and the segment, rather than aligning the RBG boundary with the boundary between the first band and the segment as in embodiment 5. As a result, the number of bits required for resource allocation in DCI can be reduced, and the overhead of resource allocation can be reduced.

Therefore, in this embodiment, we will explain the case where the RBs that make up the RBG are adaptively changed.

The base station and terminal according to this embodiment have the same basic configuration as the base station 100 and terminal 200 according to embodiment 1, so they will be described with reference to Figures 3 and 4.

The method by which the base station 100 notifies the terminal 200 of the information (bandwidth) related to the first band and the information (bandwidth) related to the segment (additional band), and the method by which the base station 100 sets the segment to the terminal 200 (starting and ending use) are the same as those in embodiment 1, so the description thereof will be omitted here. Also, the method of determining the RBG size may use any of the methods in embodiments 1 to 4.

Figure 18 shows an example of a method for determining an RBG according to this embodiment. In Figure 18, the RBG size of the virtual carrier is P=3.

When the first band and the segment that constitute the virtual carrier are continuous on the frequency axis, the base station 100 (control unit 101) sets the RBG without considering the boundary between the first band and the segment. For example, as shown in the upper diagram of FIG. 18, there exists RBG#9 that is composed of both the RB of the first band (RB#25) and the RB of the segment (RB#1, #2). Note that depending on the bandwidth of the first band and the segment, there may be cases where an RBG that includes RBs of both the first band and the segment, such as RBG#9 in the upper diagram of FIG. 18, does not exist.

On the other hand, when the first band and the segment included in the virtual carrier are discontinuous on the frequency axis, the base station 100 (control unit 101) sets the RBG so that the boundary of the RBG coincides with the boundary between the first band and the segment, as in embodiment 5. For example, as shown in the lower diagram of Figure 18, each RBG is composed of either the RB of the first band or the RB of the segment, and there is no RBG composed of both the RB of the first band and the RB of the segment.

Then, the base station 100 notifies the terminal 200 of information regarding the boundary of the RBG for the virtual carrier (information regarding the setting change) using a higher control signal (e.g., system information (MIB or SIB) or an RRC signal).

The terminal 200 receives an upper control signal notified from the base station 100, and identifies the setting of the RBG (RBs constituting the RBG) for the virtual carrier based on the received upper control signal.

Although the case where the RBG is adaptively set by signaling from the base station 100 to the terminal 200 (e.g., system information (MIB, SIB) or RRC signal) has been described, the base station 100 and the terminal 200 may adaptively set the RBG (RBs constituting the RBG) to be set in the virtual carrier based on the relationship on the frequency axis of the first band and segments included in the virtual carrier for the terminal 200.

In the above, a case has been described in which an RBG is set depending on whether the first band and the segment are continuous or discontinuous on the frequency axis, but the method of setting an RBG is not limited to this. For example, if the gap on the frequency axis between the first band and the segment is large enough (e.g., below a threshold) that it does not affect scheduling, precoding settings, channel estimation accuracy, etc., the RBG may be set in the same manner as in the above-mentioned case in which the first band and the segment are continuous on the frequency axis.

In this way, according to the present embodiment, the RBG configuration is changed depending on the continuity on the frequency axis between the first band and the segment that constitute the virtual carrier. This makes it possible to further reduce the overhead of resource allocation while suppressing the effect on the RBG caused by gaps on the frequency axis depending on the continuity on the frequency axis between the first band and the segment.

(Seventh embodiment)
In the first to sixth embodiments, a method for determining an RBG (RBG size) that is a parameter applied to resource allocation of a downlink data channel (PDSCH) has been described. In contrast, in the present embodiment, a method for determining RBs that constitute a precoding group (PRG), which is another parameter applied to resource allocation of a PDSCH, will be described.

In LTE-Advanced, there is a method of setting precoding for PDSCH in terminals using a unit of radio resource group called PRG. Like RBG, PRG is composed of multiple consecutive RBs. In LTE-Advanced, the number of RBs included in a PRG is determined according to the system bandwidth (for example, see Non-Patent Document 5).

Therefore, in this embodiment, the PRG size is determined using a method similar to the method for determining the RBG size described in embodiments 1 to 4. That is, in this embodiment, the PRG size can be determined by replacing "RBG" described in embodiments 1 to 4 with "PRG."

The base station and terminal according to this embodiment have the same basic configuration as the base station 100 and terminal 200 according to embodiment 1, so they will be described with reference to Figures 3 and 4.

The method by which the base station 100 notifies the terminal 200 of the information (bandwidth) related to the first band and the information (bandwidth) related to the segment (additional band), and the method by which the base station 100 sets the segment to the terminal 200 (starting and ending use) are the same as in embodiment 1, so the description thereof will be omitted here.

That is, in the base station 100 according to this embodiment, the control unit 101 determines a parameter (here, PRG size) for a virtual carrier consisting of a first band and a segment that is an additional band for the first band, and the transmission unit 113 (corresponding to a transceiver) uses the parameter to communicate with the terminal 200 in the second band. Also, in the terminal 200 according to this embodiment, the control unit 208 determines a parameter (PRG size) for a virtual carrier consisting of a first band and a segment that is an additional band for the first band, and the reception unit 202 (corresponding to a transceiver) uses the parameter to communicate with the base station 100 in the second band.

As a result, according to this embodiment, even when a method of adding segments is applied in a wireless communication system that flexibly supports various bandwidths in LTE-Advanced or a wireless communication system that enables flexible changes to the RF bandwidth of a terminal in NR, it is possible to appropriately determine parameters (here, PRG size) required for operation in a flexible bandwidth (e.g., virtual carrier).

In addition, when determining a PRG by regarding the first band and the band including the segment as one virtual carrier (second band), a PRG may be constructed that includes both the RBs of the first band and the RBs of the segment. In this case, if the first band and the segment are discontinuous on the frequency axis (if there is a gap on the frequency axis), multiple RBs with different channel conditions will be treated as one PRG. This is expected to have a negative impact on the precoding settings for the PRG, channel estimation accuracy, etc.

Therefore, in this embodiment, as shown in FIG. 19, the RBs constituting one PRG are composed of either the RBs of the first band or the RBs of the segment. In other words, in this embodiment, the base station 100 and the terminal 200 set the PRG so that the boundary (delimiter) of the PRG set in the virtual carrier coincides with the boundary between the first band and the segment included in the virtual carrier.

For example, as shown in FIG. 19, near the boundary between the first band and the segment in the virtual carrier, PRG#9 is formed by one RB#25 of the first band, and PRG#10 is formed by three RB#1 to #3 of the segment. That is, in FIG. 19, the boundary of the PRG at least coincides with the boundary between the first band and the segment. In other words, in FIG. 19, there is no PRG formed by resource blocks of both the first band and the segment that are discontinuous on the frequency axis. As a result, the RBs in each PRG shown in FIG. 19 are continuous on the frequency axis, so the channel conditions are comparable.

Therefore, in this embodiment, even if the first band and the segment are discontinuous on the frequency axis, it is possible to suppress the effects of gaps on the frequency axis on the precoding settings for the PRG set in the virtual carrier, the channel estimation accuracy, etc.

(Embodiment 8)
In this embodiment, a method for determining RBs constituting a PRG, which is a parameter applied to resource allocation of a downlink data channel (PDSCH), will be described.

The effect of the gap on the frequency axis described in embodiment 7 occurs when the first band and the segment are discontinuous on the frequency axis.

On the other hand, when the first band and the segment are continuous on the frequency axis, processing can be simplified by configuring the PRG without considering the boundary between the first band and the segment, rather than aligning the PRG boundary with the boundary between the first band and the segment as in embodiment 7. For example, when a PBG is configured without considering the boundary between the first band and the segment as described in embodiment 6 (e.g., the RBG in the upper diagram of Figure 18), RBG allocation and precoding settings can be simplified by configuring a PRG similarly without considering the boundary between the first band and the segment.

Therefore, in this embodiment, we will explain the case where the RBs that make up the PRG are adaptively changed.

The base station and terminal according to this embodiment have the same basic configuration as the base station 100 and terminal 200 according to embodiment 1, so they will be described with reference to Figures 3 and 4.

The method by which base station 100 notifies terminal 200 of information (bandwidth) related to the first band and information (bandwidth) related to the segment (additional band), and the method by which base station 100 sets a segment to terminal 200 (starting and ending use) are the same as in embodiment 1, so a description thereof will be omitted here. In addition, the method for determining the PRG size may be any of the methods for determining the RBG size described in embodiments 1 to 4. In other words, in this embodiment, the PRG size can be determined by replacing "RBG" described in embodiments 1 to 4 with "PRG".

Figure 20 shows an example of a method for determining a PRG according to this embodiment. In Figure 20, the PRG size of the virtual carrier is 3 (3RB).

When the first band and the segment are continuous on the frequency axis, the base station 100 (control unit 101) sets the PRG without considering the boundary between the first band and the segment. For example, as shown in the upper diagram of Figure 20, there is PRG#9 consisting of both an RB in the first band (RB#25) and RBs in the segment (RB#1, #2). Note that depending on the bandwidth of the first band and the segment, there may be cases where a PRG that includes RBs in both the first band and the segment, such as RBG#9 in the upper diagram of Figure 20, does not exist.

On the other hand, when the first band and the segment included in the virtual carrier are discontinuous on the frequency axis, the base station 100 (control unit 101) sets the PRG so that the boundary of the PRG coincides with the boundary between the first band and the segment, as in embodiment 7. For example, as shown in the lower diagram of Figure 20, each PRG is composed of either the RBs of the first band or the RBs of the segment, and there is no PRG composed of both the RBs of the first band and the RBs of the segment.

Then, the base station 100 notifies the terminal 200 of information regarding the PRG boundary for the virtual carrier (information regarding the setting change) using a higher control signal (e.g., system information (MIB or SIB) or an RRC signal).

The terminal 200 receives an upper control signal notified from the base station 100, and identifies the setting of the PRG (RBs constituting the PRG) for the virtual carrier based on the received upper control signal.

Although the case where the PRG is adaptively set by signaling from the base station 100 to the terminal 200 (e.g., system information (MIB, SIB) or RRC signal) has been described, the base station 100 and the terminal 200 may adaptively set the PRG (RBs constituting the PRG) set in the virtual carrier based on the relationship on the frequency axis of the first band and segments included in the virtual carrier for the terminal 200.

In this way, according to this embodiment, the configuration of the PRG is changed depending on the continuity on the frequency axis between the first band and the segment that constitute the virtual carrier. This makes it possible to simplify processing while suppressing the effect on the PRG caused by gaps on the frequency axis depending on the continuity on the frequency axis between the first band and the segment.

(Embodiment 9)
In the first to eighth embodiments, a method for determining RBG or PRG, which is a parameter applied to resource allocation of a downlink data channel (PDSCH), has been described. In contrast, in the present embodiment, a method for determining parameters required for a terminal to feed back channel state information (CSI: Channel State Information) for a virtual carrier (second band) to a base station will be described.

In LTE-Advanced, CSI feedback information includes wideband CQI (Channel Quality Indicator), whose feedback bandwidth is wideband (full band), and subband CQI, whose feedback bandwidth is in subband units. A subband (sometimes called a "CSI subband") is composed of multiple consecutive RBs, just like an RBG or PRG. In LTE-Advanced, the number of RBs included in a CSI subband is determined according to the system bandwidth (for example, see Non-Patent Document 5).

Therefore, in this embodiment, the CSI subband size is determined using a method similar to the method for determining the RBG size described in embodiments 1 to 4. That is, in this embodiment, the CSI subband size can be determined by replacing the "RBG" described in embodiments 1 to 4 with the "CSI subband."

The base station and terminal according to this embodiment have the same basic configuration as the base station 100 and terminal 200 according to embodiment 1, so they will be described with reference to Figures 3 and 4.

The method by which the base station 100 notifies the terminal 200 of the information (bandwidth) related to the first band and the information (bandwidth) related to the segment (additional band), and the method by which the base station 100 sets the segment to the terminal 200 (starting and ending use) are the same as in embodiment 1, so the description thereof will be omitted here.

That is, in the base station 100 according to this embodiment, the control unit 101 determines parameters (here, CSI subband size) for a virtual carrier consisting of a first band and a segment that is an additional band for the first band, and the receiving unit 115 (corresponding to a transceiver, including an extraction unit 117) uses the parameters to communicate with the terminal 200 in the second band (receives CSI feedback). Also, in the terminal 200 according to this embodiment, the control unit 208 determines parameters (CSI subband size) for a virtual carrier consisting of a first band and a segment that is an additional band for the first band, and the transmitting unit 215 (corresponding to a transceiver, including a signal allocation unit 213) uses the parameters to communicate with the base station 100 in the second band (transmits CSI feedback).

As a result, according to this embodiment, even when a method of adding segments is applied in a wireless communication system that flexibly supports various bandwidths in LTE-Advanced or a wireless communication system that enables flexible change of the RF bandwidth of a terminal in NR, it is possible to appropriately determine parameters (here, CSI subband size) required for operation in a flexible bandwidth (e.g., virtual carrier).

In addition, when determining the CSI subband by regarding the first band and the band including the segment as one virtual carrier (second band), a CSI subband including both the RBs of the first band and the RBs of the segment may be configured. In this case, if the first band and the segment are discontinuous on the frequency axis (if there is a gap on the frequency axis), multiple RBs with different channel conditions will be treated as one CSI subband. For this reason, even if the CSI subband is used, highly accurate CSI feedback is difficult.

Therefore, in this embodiment, as shown in FIG. 21, the RBs constituting one CSI subband are composed of either the RBs of the first band or the RBs of the segment. In other words, in this embodiment, the base station 100 and the terminal 200 set the CSI subband so that the boundary (delimiter) of the CSI subband set in the virtual carrier coincides with the boundary between the first band and the segment included in the virtual carrier.

For example, as shown in FIG. 21, near the boundary between the first band and the segment in the virtual carrier, CSI subband #9 is formed by one RB #25 of the first band, and CSI subband #10 is formed by three RBs #1 to #3 of the segment. That is, in FIG. 21, the boundary of the CSI subband at least coincides with the boundary between the first band and the segment. In other words, in FIG. 21, there is no CSI subband formed by resource blocks of both the first band and the segment that are discontinuous on the frequency axis. As a result, the RBs in each CSI subband shown in FIG. 21 are continuous on the frequency axis, so the channel conditions are similar.

Therefore, in this embodiment, even if the first band and the segment are discontinuous on the frequency axis, it is possible to suppress the effect of gaps on the frequency axis on the accuracy of CSI feedback using the CSI subband set in the virtual carrier.

When the terminal 200 is set to a mode that uses wideband CQI, the bandwidth of the wideband CQI may be set for each of the first band and the segment.

(Embodiment 10)
In this embodiment, a method for determining RBs constituting a CSI subband, which is a parameter required for a terminal to feed back CSI for a virtual carrier to a base station, will be described.

The effect of the gap on the frequency axis described in embodiment 9 occurs when the first band and the segment are discontinuous on the frequency axis.

On the other hand, when the first band and the segment are continuous on the frequency axis, processing can be simplified by configuring the CSI subband without considering the boundary between the first band and the segment, rather than aligning the boundary of the CSI subband with the boundary between the first band and the segment as in embodiment 9.

Therefore, in this embodiment, we will explain the case where the RBs that make up the CSI subband are adaptively configured.

The base station and terminal according to this embodiment have the same basic configuration as the base station 100 and terminal 200 according to embodiment 1, so they will be described with reference to Figures 3 and 4.

The method by which base station 100 notifies terminal 200 of information (bandwidth) related to the first band and information (bandwidth) related to the segment (additional band), and the method by which base station 100 sets a segment to terminal 200 (starting and ending use) are the same as in embodiment 1, so a description thereof will be omitted here. In addition, the method for determining the CSI subband size may be any of the methods for determining the RBG size described in embodiments 1 to 4. In other words, in this embodiment, the CSI subband size can be determined by replacing "RBG" described in embodiments 1 to 4 with "CSI subband".

Figure 22 shows an example of a method for determining a CSI subband according to this embodiment. In Figure 22, the CSI subband size of the virtual carrier is set to 3 (3RB).

When the first band and the segment are continuous on the frequency axis, the base station 100 (control unit 101) sets the CSI subband without considering the boundary between the first band and the segment. For example, as shown in the upper diagram of FIG. 22, there is CSI subband #9 consisting of both the RB of the first band (RB #25) and the RB of the segment (RB #1, #2). Note that depending on the bandwidth of the first band and the segment, there may be no CSI subband that includes RBs of both the first band and the segment, such as CSI subband #9 in the upper diagram of FIG. 22.

On the other hand, when the first band and the segment included in the virtual carrier are discontinuous on the frequency axis, the base station 100 (control unit 101) sets the CSI subbands so that the boundary between the CSI subbands coincides with the boundary between the first band and the segment, as in embodiment 9. For example, as shown in the lower diagram of FIG. 22, each CSI subband is composed of either the RBs of the first band or the RBs of the segment, and there is no CSI subband composed of both the RBs of the first band and the RBs of the segment.

Then, the base station 100 notifies the terminal 200 of information regarding the boundary of the CSI subband for the virtual carrier (information regarding the setting change) using a higher control signal (e.g., system information (MIB or SIB) or an RRC signal).

The terminal 200 receives an upper control signal notified from the base station 100, and determines the setting of the CSI subband (RBs constituting the CSI subband) for the virtual carrier based on the received upper control signal.

Although the case where the CSI subband is adaptively set by signaling from the base station 100 to the terminal 200 (e.g., system information (MIB, SIB) or RRC signal) has been described, the base station 100 and the terminal 200 may adaptively set the CSI subband (RBs constituting the CSI subband) to be set in the virtual carrier based on the relationship on the frequency axis of the first band and segments included in the virtual carrier for the terminal 200.

In this way, according to this embodiment, the configuration of the CSI subband is changed depending on the continuity on the frequency axis between the first band and the segments that constitute the virtual carrier. This makes it possible to simplify processing while suppressing the effect on the CSI feedback accuracy caused by gaps on the frequency axis depending on the continuity on the frequency axis between the first band and the segments.

(Embodiment 11)
In the first to tenth embodiments, a method for determining RBG, PRG, or CSI that a terminal feeds back to a base station, which are parameters applied to resource allocation of a downlink data channel (PDSCH), has been described. In contrast, in the present embodiment, a method for determining parameters required for a terminal to transmit a sounding reference signal (SRS: Sounding Reference Signal) for a virtual carrier (second band) to a base station will be described.

In LTE-Advanced, terminals can transmit SRS as a reference signal for measuring uplink channel quality. There are two methods for transmitting SRS: wideband SRS, which has a wideband (full band) bandwidth, and subband SRS, which has a subband bandwidth. A subband (sometimes called an "SRS subband") is composed of multiple consecutive RBs, similar to an RBG, PRG, or CSI subband. In LTE-Advanced, the number of RBs included in an SRS subband is determined according to the system bandwidth (see, for example, Non-Patent Document 6).

Therefore, in this embodiment, the SRS subband size is determined using a method similar to the method for determining the RBG size described in embodiments 1 to 4. That is, in this embodiment, the SRS subband size can be determined by replacing the "RBG" described in embodiments 1 to 4 with the "SRS subband."

The base station and terminal according to this embodiment have the same basic configuration as the base station 100 and terminal 200 according to embodiment 1, so they will be described with reference to Figures 3 and 4.

The method by which the base station 100 notifies the terminal 200 of the information (bandwidth) related to the first band and the information (bandwidth) related to the segment (additional band), and the method by which the base station 100 sets the segment to the terminal 200 (starting and ending use) are the same as in embodiment 1, so the description thereof will be omitted here.

That is, in the base station 100 according to this embodiment, the control unit 101 determines parameters (here, SRS subband size) for a virtual carrier consisting of a first band and a segment that is an additional band for the first band, and the receiving unit 115 (corresponding to a transceiver, including an extraction unit 117) uses the parameters to communicate with the terminal 200 in the second band (receive SRS). Also, in the terminal 200 according to this embodiment, the control unit 208 determines parameters (SRS subband size) for a virtual carrier consisting of a first band and a segment that is an additional band for the first band, and the transmitting unit 215 (corresponding to a transceiver, including a signal allocation unit 213) uses the parameters to communicate with the base station 100 in the second band (transmit SRS).

As a result, according to this embodiment, even when a method of adding segments is applied in a wireless communication system that flexibly supports various bandwidths in LTE-Advanced or a wireless communication system that enables flexible changes to the RF bandwidth of a terminal in NR, it is possible to appropriately determine parameters (here, SRS subband size) required for operation in a flexible bandwidth (e.g., virtual carrier).

In addition, when determining an SRS subband by regarding the first band and the band including the segment as one virtual carrier (second band), there is a possibility that an SRS subband including both the RBs of the first band and the RBs of the segment is configured. In this case, if the first band and the segment are discontinuous on the frequency axis (if there is a gap on the frequency axis), multiple RBs with different channel conditions will be treated as one SRS subband. For this reason, even if the base station 100 uses the SRS subband, it is difficult to measure channel quality with high accuracy.

Therefore, in this embodiment, as shown in FIG. 23, the RBs constituting one SRS subband are composed of either the RBs of the first band or the RBs of the segment. In other words, in this embodiment, the base station 100 and the terminal 200 set the SRS subband so that the boundary (delimiter) of the SRS subband set in the virtual carrier coincides with the boundary between the first band and the segment included in the virtual carrier.

For example, as shown in FIG. 23, near the boundary between the first band and the segment in the virtual carrier, SRS subband #9 is formed by one RB #25 of the first band, and SRS subband #10 is formed by three RBs #1 to #3 of the segment. That is, in FIG. 23, the boundary of the SRS subband at least coincides with the boundary between the first band and the segment. In other words, in FIG. 23, there is no SRS subband formed by resource blocks of both the first band and the segment that are discontinuous on the frequency axis. As a result, the RBs in each SRS subband shown in FIG. 23 are continuous on the frequency axis, so the channel conditions are similar.

Therefore, in this embodiment, even if the first band and the segment are discontinuous on the frequency axis, it is possible to suppress the effect of gaps on the frequency axis on the accuracy of channel quality measurement using the SRS subband set in the virtual carrier.

When the terminal 200 is set to a mode using wideband SRS, the bandwidth of the wideband SRS may be set for each of the first band and the segment.

(Embodiment 12)
In this embodiment, a method for determining RBs constituting an SRS subband, which is a parameter required for a terminal to transmit an SRS for a virtual carrier to a base station, will be described.

The effect of the gap on the frequency axis described in embodiment 11 occurs when the first band and the segment are discontinuous on the frequency axis.

On the other hand, when the first band and the segment are continuous on the frequency axis, processing can be simplified by configuring the SRS subband without considering the boundary between the first band and the segment, rather than aligning the boundary of the SRS subband with the boundary between the first band and the segment as in embodiment 11.

Therefore, in this embodiment, we will explain the case where the RBs that make up the SRS subband are adaptively changed.

The base station and terminal according to this embodiment have the same basic configuration as the base station 100 and terminal 200 according to embodiment 1, so they will be described with reference to Figures 3 and 4.

The method by which base station 100 notifies terminal 200 of information (bandwidth) related to the first band and information (bandwidth) related to the segment (additional band), and the method by which base station 100 sets a segment to terminal 200 (starting and ending use) are the same as in embodiment 1, so a description thereof will be omitted here. In addition, the method for determining the SRS subband size may be any of the methods for determining the RBG size described in embodiments 1 to 4. In other words, in this embodiment, the SRS subband size can be determined by replacing "RBG" described in embodiments 1 to 4 with "SRS subband".

Figure 24 shows an example of a method for determining an SRS subband according to this embodiment. In Figure 24, the SRS subband size of the virtual carrier (second band) is 3 (3RB).

When the first band and the segment are continuous on the frequency axis, the base station 100 (control unit 101) sets the SRS subband without considering the boundary between the first band and the segment. For example, as shown in the upper diagram of FIG. 24, there is a CSI subband #9 consisting of both an RB (RB #25) of the first band and RBs (RB #1, #2) of the segment. Note that, depending on the bandwidth of the first band and the segment, there may be no CSI subband that includes RBs of both the first band and the segment, such as CSI subband #9 in the upper diagram of FIG. 24.

On the other hand, when the first band and the segment included in the virtual carrier are discontinuous on the frequency axis, the base station 100 (control unit 101) sets the SRS subband so that the boundary of the SRS subband coincides with the boundary between the first band and the segment, as in embodiment 11. For example, as shown in the lower diagram of Figure 24, each SRS subband is composed of either the RBs of the first band or the RBs of the segment, and there is no SRS subband composed of both the RBs of the first band and the RBs of the segment.

Then, the base station 100 notifies the terminal 200 of information regarding the boundary of the SRS subband for the virtual carrier (information regarding the setting change) using a higher control signal (e.g., system information (MIB or SIB) or an RRC signal).

The terminal 200 receives an upper control signal notified from the base station 100, and determines the setting of the SRS subband (RBs constituting the SRS subband) for the virtual carrier based on the received upper control signal.

Although the case where the SRS subband is adaptively set by signaling from the base station 100 to the terminal 200 (e.g., system information (MIB, SIB) or RRC signal) has been described, the base station 100 and the terminal 200 may adaptively set the SRS subband (RBs constituting the SRS subband) set in the virtual carrier based on the relationship on the frequency axis of the first band and segments included in the virtual carrier for the terminal 200.

In this way, according to this embodiment, the configuration of the SRS subband is changed depending on the continuity on the frequency axis between the first band and the segments that constitute the virtual carrier. This makes it possible to simplify processing while suppressing the effect of gaps on the frequency axis on the accuracy of channel quality measurement at base station 100, depending on the continuity on the frequency axis between the first band and the segments.

Above, each embodiment of this disclosure has been described.

In the fifth to twelfth embodiments, a method for aligning the boundaries of the RBG, PRG, CSI subband, or SRS subband with the boundaries of the first band and the segment when the first band and the segment are discontinuous on the frequency axis has been described. However, when the first band and the segment are discontinuous on the frequency axis, the RBG, PRG, CSI subband, or SRS subband may be configured without considering the boundaries of the first band and the segment. In such a case, for example, in a PRG (e.g., PRG#9 in the upper diagram of FIG. 20) composed of RBs of the first band and RBs of the segment, different precoding may be applied to RBs in the same PRG (RB#25 and RB#1,#2 in PRG#9 in the upper diagram of FIG. 20). Furthermore, with regard to the CSI subbands and SRS subbands, terminal 200 may drop transmissions of the CSI subband (e.g., CSI subband #9 in the upper diagram of FIG. 22) and SRS subband (e.g., SRS subband #9 in the upper diagram of FIG. 24) that are composed of RBs of the first band and RBs of a segment.

The present disclosure can be realized by software, hardware, or software linked to hardware. Each functional block used in the description of the above embodiment may be realized partially or entirely as an LSI, which is an integrated circuit, and each process described in the above embodiment may be controlled partially or entirely by one LSI or a combination of LSIs. The LSI may be composed of individual chips, or may be composed of one chip to include some or all of the functional blocks. The LSI may have input and output of data. Depending on the degree of integration, the LSI may be called an IC, a system LSI, a super LSI, or an ultra LSI. The method of integration is not limited to LSI, and may be realized by a dedicated circuit, a general-purpose processor, or a dedicated processor. In addition, a field programmable gate array (FPGA) that can be programmed after LSI manufacture, or a reconfigurable processor that can reconfigure the connections and settings of circuit cells inside the LSI may be used. The present disclosure may be realized as digital processing or analog processing. Furthermore, if an integrated circuit technology that can replace LSI appears due to advances in semiconductor technology or other derived technologies, it is natural that this technology can be used to integrate functional blocks. The application of biotechnology, etc. is also a possibility.

The base station of the present disclosure includes a circuit for determining parameters for a second band consisting of the first band and a segment that is an additional band to the first band, and a transceiver for communicating with the terminal in the second band using the parameters.

In the base station of the present disclosure, the parameter is a resource block group (RBG) size set for the second band, and the circuit determines the RBG size based on the bandwidth of the second band.

In the base station of the present disclosure, the parameter is a resource block group (RBG) size set for the second band, and the circuit determines the RBG size for the second band to be X times (where X is an integer equal to or greater than 2) the RBG size set based on the bandwidth of the first band.

In the base station of the present disclosure, the parameter is a resource block group (RBG) size set for the second band, and the circuit determines a power of two as the RBG size.

In the base station disclosed herein, the RBG size is variable, and the RBG size is notified from the base station to the terminal.

In the base station of the present disclosure, the circuit sets the RBGs so that the boundaries of the multiple RBGs set in the second band coincide with the boundaries between the first band and the segment.

The terminal of the present disclosure includes a circuit that determines parameters for a second band consisting of the first band and a segment that is an additional band to the first band, and a transceiver that uses the parameters to communicate with a base station in the second band.

The communication method disclosed herein determines parameters for a second band consisting of the first band and a segment that is an additional band to the first band, and communicates with the terminal in the second band using the parameters.

The communication method disclosed herein determines parameters for a second band consisting of the first band and a segment that is an additional band to the first band, and communicates with a base station in the second band using the parameters.

One aspect of the present disclosure is useful for mobile communication systems.

100 Base station 101, 208 Control unit 102 Data generation unit 103, 106, 109, 210 Encoding unit 104, 107, 110, 211 Modulation unit 105 Higher control signal generation unit 108 Downlink control signal generation unit 111, 213 Signal allocation unit 112, 214 IFFT unit 113, 215 Transmission unit 114, 201 Antenna 115, 202 Reception unit 116, 203 FFT unit 117, 204 Extraction unit 118 CSI demodulation unit 119 SRS measurement unit 205 Downlink control signal demodulation unit 206 Higher control signal demodulation unit 207 Downlink data signal demodulation unit 209 CSI generation unit 212 SRS generation unit

Claims (17)

A circuit for setting the number of resource blocks constituting a resource block group, the resource block group being a unit for allocating resources to a terminal in a first band or a second band having a bandwidth different from that of the first band;
A transceiver that communicates with a terminal using the resources;
Equipped with
a subcarrier spacing in the first band and a subcarrier spacing in the second band are each set to one of a plurality of subcarrier spacings including 15 kHz, 30 kHz, and 60 kHz, and the number of resource blocks determined in the first band and the number of resource blocks determined in the second band are a power of two.
base station. the number of resource blocks in the first band is determined based on a bandwidth of the first band, and the number of resource blocks in the second band is determined based on a bandwidth of the second band.
The base station according to claim 1 . The number of resource blocks in the second band is determined based on a bandwidth of the second band, not a bandwidth of the first band.
A base station as claimed in claim 1 or 2. A subcarrier spacing constituting a resource block in the second band is different from a subcarrier spacing constituting a resource block in the first band.
A base station according to any one of claims 1 to 3. The number of subcarriers constituting the resource block is 12, regardless of the subcarrier spacing.
The base station according to claim 4. The transceiver transmits information regarding the number of resource blocks constituting the resource block group to the terminal.
A base station according to any one of claims 1 to 5. The transceiver transmits information regarding a bandwidth of the first band and information regarding a bandwidth of the second band to the terminal.
A base station according to any one of claims 1 to 6. The transceiver transmits control information to the terminal in the first band and transmits data to the terminal in the second band.
A base station according to any one of claims 1 to 7. setting the number of resource blocks constituting a resource block group, the resource block group being a unit for allocating resources to a terminal in a first band or a second band having a bandwidth different from that of the first band;
using the resource to communicate with a terminal;
Equipped with
a subcarrier spacing in the first band and a subcarrier spacing in the second band are each set to one of a plurality of subcarrier spacings including 15 kHz, 30 kHz, and 60 kHz, and the number of resource blocks determined in the first band and the number of resource blocks determined in the second band are a power of two.
Communication method. the number of resource blocks in the first band is determined based on a bandwidth of the first band, and the number of resource blocks in the second band is determined based on a bandwidth of the second band.
The communication method according to claim 9. The number of resource blocks in the second band is determined based on a bandwidth of the second band, not a bandwidth of the first band.
The communication method according to claim 9 or 10. A subcarrier spacing constituting a resource block in the second band is different from a subcarrier spacing constituting a resource block in the first band.
A communication method according to any one of claims 9 to 11. The number of subcarriers constituting the resource block is 12, regardless of the subcarrier spacing.
The communication method according to claim 12. Transmitting information regarding the number of resource blocks constituting the resource block group to the terminal;
A communication method according to any one of claims 9 to 13. Transmitting information regarding the bandwidth of the first band and information regarding the bandwidth of the second band to the terminal;
A communication method according to any one of claims 9 to 14. Transmitting control information to the terminal in the first band and transmitting data to the terminal in the second band;
A communication method according to any one of claims 9 to 15. A process of setting the number of resource blocks constituting a resource block group, which is a unit for allocating resources in a first band or a second band having a bandwidth different from that of the first band to a terminal;
A process of communicating with a terminal using the resource;
Control the
a subcarrier spacing in the first band and a subcarrier spacing in the second band are each set to one of a plurality of subcarrier spacings including 15 kHz, 30 kHz, and 60 kHz, and the number of resource blocks determined in the first band and the number of resource blocks determined in the second band are a power of two.
Integrated circuits.

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