Communication device and communication method

Abstract

In the communication device and communication system of the present invention, the communication device includes: a circuit that determines the number of resource blocks forming a resource block group, where the resource block group is a unit for allocating resources to the communication device in a first frequency band or a second frequency band, and the second frequency band is an extended frequency band extended from the first frequency band; and a transceiver that communicates with a base station using the resources. In the communication device, one of the number of resource blocks determined for the first frequency band and the number of resource blocks determined for the second frequency band is an integer multiple of the other, the subcarrier spacing in the first frequency band and the subcarrier spacing in the second frequency band can be configured separately, and the number of resource blocks set for the first frequency band and the number of resource blocks set for the second frequency band are powers of 2.

Description

[0001] This application is a divisional application of a Chinese patent application with an application date of January 6, 2017, an application number of 201780079519.5, an invention title of "Base Station, Terminal, and Communication Method", and an applicant of Panasonic Intellectual Property Corporation of America. Technical Field

[0002] The present disclosure relates to a base station, a terminal, and a communication method. Background Art

[0003] With the recent expansion of services using mobile broadband, the data traffic in mobile communications has grown exponentially. For this reason, expanding the data transmission capacity for upcoming features is considered an urgent task. In addition, in the coming years, the Internet of Things (IoT) in which any kind of "thing" is connected together via the Internet is expected to grow rapidly. To support the diversification of IoT services, rapid progress is required not only in terms of data transmission capacity but also in various requirements such as low latency and communication area (coverage). Considering this background, the technical development and standardization of the fifth-generation mobile communication system (5G) have been carried out, and compared with the fourth-generation mobile communication system (4G), 5G has significantly improved performance and features.

[0004] Advanced Long Term Evolution (LTE), which is known as a 4G radio access technology (RAT), has been standardized by the 3rd generation partnership project (3GPP). 3GPP has been developing a new RAT (NR), which does not have to be backward compatible with advanced LTE in 5G standardization.

[0005] In the enhancement of advanced LTE, research has been conducted on improving the system throughput by expanding the operating bandwidth (1.4, 3, 5, 10, 15, and 20 MHz) of the existing LTE system, thereby flexibly supporting various bandwidths (such as 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) to make the most use of the frequency bands allocated to operators (for example, see Non-Patent Literature (hereinafter referred to as "NPL") 1).

[0006] In NR, it is claimed to support an operating bandwidth of several hundred MHz. At the same time, the power consumption of the terminal increases proportionally with the radiofrequency (RF) bandwidth. Therefore, in NR, when the terminal receives downlink (DL) control signals using a bandwidth similar to the network operating bandwidth in LTE, the power consumption of the terminal increases. Therefore, in NR, research has been conducted on allowing the terminal to receive DL control signals using a bandwidth narrower than the network operating bandwidth and enabling the RF bandwidth of the terminal to be appropriately and flexibly changed (e.g., the RF bandwidth of the terminal is extended for the transmission and / or reception of data signals) (see, for example, NPL 2 and 3).

[0007] Carrier Aggregation (CA) is a method for extending the bandwidth introduced in advanced LTE. CA is a method for extending the bandwidth by combining multiple frequency bands of the operating bandwidth of the existing LTE system. Therefore, when CA is applied to the above system with a flexibly changeable bandwidth, some frequency bands (e.g., 1.8, 2.0, 2.2, 4.6, 6.2, 7.0, 14, and 19 MHz) are not available in the combination of the operating bandwidth of the existing LTE system. In addition, CA for combining narrowband component carriers requires the transmission and scheduling of control signals for each component carrier, resulting in an increased overhead of control signals and thus inefficiency. Additionally, even when the operating bandwidth is narrowband, the terminal needs to have CA performance. For example, in the case of 11 MHz, the terminal is required to have the performance of combining three component carriers, which are 5 MHz + 3 MHz + 3 MHz. Therefore, the complexity of the terminal increases.

[0008] In this regard, as a method for extending the frequency band without using CA performance and mechanisms, a method has been discussed in which an extended frequency band of a so-called "segment" is added to the existing LTE frequency band (see, for example, NPL 4). In this method, the existing LTE frequency band (hereinafter referred to as the "Backward Compatible Carrier (BCC)") and this segment can be scheduled by one DL control signal, so that the overhead of the control signal can be reduced. Additionally, even when the operating bandwidth is narrowband, this method does not require the terminal to have CA performance, enabling the complexity of the terminal to be reduced. Therefore, this method of adding a segment is more effective than the CA mechanism for flexibly supporting various bandwidths in the above system.

[0009] Citation List

[0010] Non-Patent Literature

[0011] NPL 1

[0012] RP-151890, "Motivation for new work item proposal on LTE bandwidth flexibility enhancements," Huawei, China Unicom, HiSilicon, RAN#70, December 2015

[0013] NPL 2

[0014] 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

[0015] NPL 3

[0016] RAN1#85 chairman’s note

[0017] NPL 4

[0018] R1-130786, "Way Forward on synchronized carrier and segment," Panasonic, KDDI, AT&T, Qualcomm, Motorola Mobility, New Postcom, Interdigital, RAN1#72, February 2013

[0019] NPL 5

[0020] 3GPP TS 36.213 V13.3.0, "Evolved Universal Terrestrial Radio Access (E-UTRA); Physical layer procedures (Release 13)," September 2016

[0021] NPL 6

[0022] 3GPP TS 36.211 V13.3.0, "Evolved Universal Terrestrial Radio Access (E-UTRA); Physical channels and modulation (Release 13)", September 2016 SUMMARY OF THE INVENTION

[0023] As described above, it is necessary to study detailed mechanisms such as a method for determining parameters required for operations in a flexible bandwidth (e.g., a bandwidth with segments added) in the case where a method of adding segments is flexibly applied to a radio communication system supporting various bandwidths in the above-mentioned advanced LTE and a radio communication system capable of flexibly changing the RF bandwidth of a terminal in NR.

[0024] A non-limiting and exemplary embodiment helps to provide a base station, a terminal, and a communication method capable of appropriately determining parameters required for operations in a flexible bandwidth.

[0025] A communication device according to an aspect of the present disclosure includes: a circuit that determines the number of resource blocks forming a resource block group, where the resource block group is a unit for allocating resources to the communication device in a first frequency band or a second frequency band, and the second frequency band is an extended frequency band to which the first frequency band is extended; and a transceiver that communicates with a base station using the resources. In the communication device, one of the number of resource blocks determined for the first frequency band and the number of resource blocks determined for the second frequency band is an integer multiple of the other, the subcarrier spacing in the first frequency band and the subcarrier spacing in the second frequency band can be respectively configured, and the number of resource blocks set for the first frequency band and the number of resource blocks set for the second frequency band are powers of 2.

[0026] A communication method according to an aspect of the present disclosure includes the following steps: determining the number of resource blocks forming a resource block group, where the resource block group is a unit for allocating resources to a terminal in a first frequency band or a second frequency band, and the second frequency band is an extended frequency band to which the first frequency band is extended; and communicating with a base station using the resources. In the communication method, one of the number of resource blocks determined for the first frequency band and the number of resource blocks determined for the second frequency band is an integer multiple of the other, the subcarrier spacing in the first frequency band and the subcarrier spacing in the second frequency band can be respectively configured, and the number of resource blocks set for the first frequency band and the number of resource blocks set for the second frequency band are powers of 2.

[0027] A base station according to one aspect of the present disclosure includes: a circuit that determines parameters for a frequency band composed of a first frequency band and segments that are additional frequency bands of the first frequency band, and the frequency band composed of the first frequency band and the segments is referred to as a second frequency band; and a transceiver unit that communicates with a terminal in the second frequency band using the parameters.

[0028] A terminal according to one aspect of the present disclosure includes: a circuit that determines parameters for a frequency band composed of a first frequency band and segments that are additional frequency bands of the first frequency band, and the frequency band composed of the first frequency band and the segments is referred to as a second frequency band; and a transceiver unit that communicates with a base station in the second frequency band using the parameters.

[0029] A communication method according to one aspect of the present disclosure includes: determining parameters for a frequency band composed of a first frequency band and segments that are additional frequency bands of the first frequency band, and the frequency band composed of the first frequency band and the segments is referred to as a second frequency band; and communicating with a terminal in the second frequency band using the parameters.

[0030] A communication method according to one aspect of the present disclosure includes: determining parameters for a frequency band composed of a first frequency band and segments that are additional frequency bands of the first frequency band, and the frequency band composed of the first frequency band and the segments is referred to as a second frequency band; and communicating with a base station in the second frequency band using the parameters.

[0031] Note that the above general or specific aspects can be implemented by a system, apparatus, method, integrated circuit, computer program, or recording medium, or any combination of a system, apparatus, method, integrated circuit, computer program, and recording medium.

[0032] According to one aspect of the present disclosure, parameters required for operations in a flexible bandwidth can be appropriately determined.

[0033] The description and the drawings clearly show more advantages and effects of the aspects of the present disclosure. These advantages and / or effects are provided by some embodiments and the features disclosed in the description and the drawings, but it is not necessary to provide all of these advantages and / or effects in order to obtain one or more of the same features. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a block diagram showing the configuration of a base station according to Embodiment 1;

[0035] Figure 2 is a block diagram showing the configuration of a terminal according to Embodiment 1;

[0036] Figure 3 is a block diagram showing the configuration of a base station according to Embodiment 1;

[0037] Figure 4 is a block diagram showing the configuration of a terminal according to Embodiment 1;

[0038] Figure 5 It is a diagram showing a configuration example of RBG;

[0039] Figure 6 It is a diagram showing the flow of the RBG size determination method according to Embodiment 1;

[0040] Figure 7 It is a diagram showing an example of the RBG size determination method according to Embodiment 1;

[0041] Figure 8 It is a diagram showing an example of the RBG size determination method according to Variant 1 of Embodiment 1;

[0042] Figure 9 It is a diagram showing an example of the RBG size determination method according to Variant 2 of Embodiment 1;

[0043] Figure 10 It is a diagram for describing the problem of Embodiment 2;

[0044] Figure 11 It is a diagram showing an example of the RBG size determination method according to Embodiment 2;

[0045] Figure 12 It is a diagram showing an example of the RB grid between parameter sets (numerologies) with different subcarrier spacings;

[0046] Figure 13 It is a diagram showing an example of the RB grid and RBG between parameter sets with different subcarrier spacings;

[0047] Figure 14 It is a diagram showing an example of the RBG size determination method according to Embodiment 3;

[0048] Figure 15 It is a diagram showing an example of the RBG size determination method according to Embodiment 4;

[0049] Figure 16 It is a diagram showing an RBG configuration example where the first frequency band and the segment are discontinuous in the frequency domain;

[0050] Figure 17 It is a diagram showing an example of the RBG size determination method according to Embodiment 5;

[0051] Figure 18 It is a diagram showing an example of the RBG size determination method according to Embodiment 6;

[0052] Figure 19 It is a diagram showing an example of the RBG size determination method according to Embodiment 7;

[0053] Figure 20A diagram showing an example of the RBG size determination method according to Embodiment 8;

[0054] Figure 21 A diagram showing an example of the CSI sub - band size determination method according to Embodiment 9;

[0055] Figure 22 A diagram showing an example of the CSI sub - band size determination method according to Embodiment 10;

[0056] Figure 23 A diagram showing an example of the SRS sub - band size determination method according to Embodiment 11; and

[0057] Figure 24 A diagram showing an example of the SRS sub - band size determination method according to Embodiment 12. Detailed Description of the Invention

[0058] Hereinafter, a detailed description of embodiments of the present disclosure will be given with reference to the accompanying drawings.

[0059] In one aspect of the present disclosure, an extended band including BCC and segments is regarded as a virtual carrier, and a method for determining parameters required for operations regarding the virtual carrier will be described. According to this method, the base station can use a single DL control signal to perform scheduling for resource allocation for the extended band including BCC and segments after adding segments. Additionally, the change in the existing resource allocation mechanism can be suppressed to a very small extent.

[0060] (Embodiment 1)

[0061] Overview of the Communication System

[0062] The communication system according to each embodiment of the present disclosure includes a base station 100 and a terminal 200.

[0063] Figure 1 A block diagram showing the configuration of the base station 100 according to each embodiment of the present disclosure. In Figure 1 the shown base station 100, a control unit 101 determines parameters (the RBG size herein) for a second band (virtual carrier) composed of a first band and segments that are additional bands to the first band, and a transmission unit 113 (corresponding to a transceiver unit and including a signal dispatching unit 111) communicates with the terminal 200 in the second band using the parameters.

[0064] Figure 2 A block diagram showing the configuration of the terminal 200 according to each embodiment of the present disclosure. In Figure 2In the terminal 200 shown, a control unit 208 determines parameters (RBG size) for a second frequency band (virtual carrier) composed of a first frequency band and segments that are additional frequency bands of the first frequency band, and a receiving unit 202 (corresponding to a transceiver unit and including an extraction unit 204) communicates with a base station 100 in the second frequency band using the parameters.

[0065] Note that hereinafter, the term "BCC" or "first RF frequency band" is the frequency band required for the terminal 200 to receive a DL control signal (e.g., Downlink Control Information (DCI)), which is defined as the "first frequency band".

[0066] In addition, hereinafter, an extended frequency band including the BCC and segments after adding segments to the first frequency band is defined as a "virtual carrier" or "second frequency band".

[0067] Configuration of the base station

[0068] Figure 3 is a block diagram showing the configuration of a base station 100 according to Embodiment 1 of the present disclosure. In Figure 3 it, the base station 100 includes a control unit 101, a data generation unit 102, an encoding unit 103, a modulation unit 104, a high-layer control signal generation unit 105, an encoding unit 106, a modulation unit 107, a DL control signal generation unit 108, an encoding unit 109, a modulation unit 110, a signal distribution unit 111, an Inverse Fast Fourier Transform (IFFT) processing unit 112, a transmission unit 113, an antenna 114, a receiving unit 115, a Fast Fourier Transform (FFT) processing unit 116, an extraction unit 117, a Channel State Information (CSI) demodulation unit 118, and a Sounding Reference Signal (SRS) measurement unit 119.

[0069] The control unit 101 determines the Resource Block Group (RBG) size of the virtual carrier (second frequency band). At this time, the control unit 101 outputs information indicating the determined RBG size of the virtual carrier to the signal distribution unit 111. Note that the control unit 101 may output information indicating the determined RBG size of the virtual carrier to the high-layer control signal generation unit 105.

[0070] In addition, the control unit 101 determines information regarding CSI feedback or SRS, and outputs the determined information to the high-layer control signal generation unit 105 and the extraction unit 117 (details will be given in Embodiments 9 to 12 below). Further, when the configuration of the RBG (RBG size or RBG boundary) of the virtual carrier is configurable, the control unit 101 outputs information regarding the configuration change to the high-layer control signal generation unit 105 (details will be given in Embodiments 4 and 6 below).

[0071] In addition, the control unit 101 determines, for example, the radio resource allocation of the DL data to the terminal 200 using the determined RBG, and outputs DL resource allocation information indicating the resource allocation of the DL data to the DL control signal generation unit 108 and the signal dispatching unit 111.

[0072] The data generation unit 102 generates DL data for the terminal 200 and outputs the DL data to the encoding unit 103.

[0073] The encoding unit 103 applies error correction coding to the DL data input from the data generation unit 102 and outputs the encoded data signal to the modulation unit 104.

[0074] The modulation unit 104 modulates the data signal input from the encoding unit 103 and outputs the data modulation signal to the signal dispatching unit 111.

[0075] The high-layer control signal generation unit 105 generates a control information bit sequence using the information input from the control unit 101 and outputs the generated control information bit sequence to the encoding unit 106. Further, the high-layer control signal generation unit 105 generates a control information bit sequence using the information regarding the first frequency band (BCC or first RF frequency band) (e.g., bandwidth) and the information regarding the segmentation (additional frequency band) (e.g., bandwidth) and outputs the generated control information bit sequence to the encoding unit 106.

[0076] The encoding unit 106 applies error correction coding to the control information bit sequence input from the high-layer control signal generation unit 105 and outputs the encoded control signal to the modulation unit 107.

[0077] The modulation unit 107 modulates the control signal input from the encoding unit 106 and outputs the modulated control signal to the signal dispatching unit 111.

[0078] The DL control signal generation unit 108 generates a control information bit sequence using the DL resource allocation information input from the control unit 101 and the information indicating the RBG size of the virtual carrier, and outputs the generated control information bit sequence to the encoding unit 109. Note that the control information may be sent to multiple terminals, such that the DL control signal generation unit 108 can generate the bit sequence by including the terminal ID of each terminal in the control information for the corresponding one terminal.

[0079] The encoding unit 109 applies error correction coding to the control information bit sequence input from the DL control signal generation unit 108, and outputs the encoded control signal to the modulation unit 110.

[0080] The modulation unit 110 modulates the control signal input from the encoding unit 109, and outputs the modulated control signal to the signal dispatching unit 111.

[0081] The signal dispatching unit 111 maps the data signal input from the modulation unit 104 to radio resources based on the DL resource allocation information input from the control unit 101 or the information about the RBG. In addition, the signal dispatching unit 111 maps the control signal input from the modulation unit 107 or the modulation unit 110 to radio resources. The signal dispatching unit 111 outputs the DL signal with the mapped signals to the IFFT processing unit 112.

[0082] The IFFT processing unit 112 applies a transmission waveform generation process such as Orthogonal Frequency Division Multiplexing (OFDM) to the signal input from the signal dispatching unit 111. In the case of OFDM transmission with a Cyclic Prefix (CP) (not shown) added, the IFFT processing unit 112 adds the CP. The IFFT processing unit 112 outputs the generated transmission waveform to the transmission unit 113.

[0083] The transmission unit 113 applies radio frequency (RF) processing such as digital-to-analog (D / A) conversion and / or up-conversion to the signal input from the IFFT processing unit 112, and transmits a radio signal to the terminal 200 via the antenna 114.

[0084] The receiving unit 115 applies RF processing such as down-conversion or analog-to-digital (A / D) conversion to the signal waveform of the CSI feedback signal or SRS received from the terminal 200 via the antenna 114, and outputs the resulting received signal to the FFT processing unit 116.

[0085] The FFT processing unit 116 applies FFT processing to the received signal input from the receiving unit 115. This FFT processing is used to convert the time-domain signal into a frequency-domain signal. The FFT processing unit 116 outputs the frequency-domain signal obtained through the FFT processing to the extraction unit 117.

[0086] Based on the information received from the control unit 101 (information regarding CSI feedback or information regarding SRS), the extraction unit 117 extracts the radio resources on which the CSI feedback signal or SRS is transmitted from the signal input from the FFT processing unit 116, and outputs the components of the extracted radio resources (CSI feedback signal or SRS signal) to the CSI demodulation unit 118 or the SRS measurement unit 119.

[0087] 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 for DL allocation control.

[0088] The SRS measurement unit 119 measures the UL 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 for UL allocation control (not shown).

[0089] Configuration of the terminal

[0090] Figure 4 is a block diagram showing the configuration of the terminal 200 according to Embodiment 1 of the present disclosure. In Figure 4 it, the terminal 200 includes an antenna 201, a receiving unit 202, an FFT processing unit 203, an extraction unit 204, a DL control signal demodulation unit 205, a high-layer control signal demodulation unit 206, a DL data signal demodulation unit 207, a control unit 208, a CSI generation unit 209, an encoding unit 210, a modulation unit 211, an SRS generation unit 212, a signal dispatching unit 213, an IFFT processing unit 214, and a transmitting unit 215.

[0091] The receiving unit 202 applies RF processing such as down-conversion or analog-to-digital (A / D) conversion to the signal waveform of the DL signal (data signal and control signal) received from the base station 100 via the antenna 201, and outputs the resulting received signal (baseband signal) to the FFT processing unit 203.

[0092] The FFT processing unit 203 applies FFT processing to the signal (time-domain signal) input from the receiving unit 202. This FFT processing is used to convert the time-domain signal into a frequency-domain signal. The FFT processing unit 203 outputs the frequency-domain signal obtained through the FFT processing to the extraction unit 204.

[0093] Based on the control information input from the control unit 208, the extraction unit 204 extracts the DL control signal from the signal input from the FFT processing unit 203 and outputs the DL control signal to the DL control signal demodulation unit 205. In addition, the extraction unit 204 extracts the high-layer control signal and the DL data signal based on the control information input from the control unit 208, outputs the high-layer control signal to the high-layer control signal demodulation unit 206, and outputs the DL data signal to the DL data signal demodulation unit 207.

[0094] The DL control signal demodulation unit 205 blindly decodes the DL control signal input from the extraction unit 204, and when it is determined that the DL control signal is the control signal of the terminal 200 of the DL control signal demodulation unit 205, the DL control signal demodulation unit 205 demodulates the control signal and outputs the control signal to the control unit 208.

[0095] The high-layer control signal demodulation unit 206 demodulates the high-layer control signal input from the extraction unit 204 and outputs the demodulated high-layer control signal to the control unit 208.

[0096] The DL data signal demodulation unit 207 demodulates the DL data signal input from the extraction unit 204 to obtain a demodulated signal.

[0097] Based on the DL resource allocation information indicated by the control signal input from the DL control signal demodulation unit 205, the control unit 208 calculates the radio resource allocation for the DL data signal and outputs the information indicating the calculated radio resource allocation to the extraction unit 204.

[0098] In addition, based on the DL control signal input from the DL control signal demodulation unit 205 or the high-layer control signal input from the high-layer control signal demodulation unit 206, the control unit 208 configures the RBG (RBG size or RBG boundary) for the virtual carrier (second frequency band) using the method to be described below. The control unit 208 then outputs the information about the configured RBG to the extraction unit 204.

[0099] Based on the DL control signal input from the DL control signal demodulation unit 205 or the high-layer control signal input from the high-layer control signal demodulation unit 206, the control unit 208 configures the radio resources for CSI feedback or SRS and outputs the information about the configured CSI feedback or SRS to the signal dispatching unit 213 (details will be given in Embodiments 9 to 12 below).

[0100] The CSI generation unit 209 generates a CSI feedback bit sequence using the measurement result of the DL channel quality measured in the terminal 200 and outputs the CSI feedback bit sequence to the encoding unit 210.

[0101] The encoding unit 210 applies error correction encoding to the CSI feedback bit sequence input from the CSI generation unit 209, and outputs the encoded CSI signal to the modulation unit 211.

[0102] The modulation unit 211 modulates the CSI signal input from the encoding unit 210, and outputs the modulated CSI signal to the signal dispatching unit 213.

[0103] The SRS generation unit 212 generates an SRS sequence, and outputs the SRS sequence to the signal dispatching unit 213.

[0104] The signal dispatching unit 213 maps the CSI signal input from the modulation unit 211 and the SRS sequence input from the SRS generation unit 212 to the corresponding radio resources indicated by the control unit 208. The signal dispatching unit 213 outputs the UL signal to which the signal is mapped to the IFFT processing unit 214.

[0105] The IFFT processing unit 214 applies transmission waveform generation processing such as OFDM to the signal input from the signal dispatching unit 213. In the case of OFDM transmission with a cyclic prefix (CP) added, the IFFT processing unit 214 adds a CP (not shown). Alternatively, when the IFFT processing unit 214 is going to generate a single carrier waveform, a discrete Fourier transform (DFT) processing unit (not shown) may be added in front of the signal dispatching unit 213. The IFFT processing unit 214 outputs the generated transmission waveform to the transmission unit 215.

[0106] The transmission unit 215 applies radio frequency (RF) processing such as digital-to-analog (D / A) conversion and / or up-conversion to the signal input from the IFFT processing unit 214, and transmits a radio signal to the base station 100 via the antenna 201.

[0107] Operations of the base station 100 and the terminal 200

[0108] The operations of the base station 100 and the terminal 200 having the above configuration will be described in detail below.

[0109] In this embodiment, in a radio communication system that flexibly supports various bandwidths in the above-mentioned advanced LTE or in a radio communication system that can flexibly change the RF bandwidth of the terminal 200 in NR, the base station 100 and the terminal 200 determine the parameters required for communication between the base station 100 and the terminal 200 for a "virtual carrier (second band)", which is a first band including segments added to the first band and an extended band of the segments.

[0110] In advanced LTE or NR, the signal waveform adopts OFDM or single-carrier frequency division multiple access (SC-FDMA). These signal waveforms achieve multiple access between the base station and multiple terminals by using different subcarriers for each terminal.

[0111] A resource block (RB) is the smallest unit of radio resource allocation. In advanced LTE or NR, regardless of the subcarrier spacing, an RB consists of 12 subcarriers. However, in addition to 12 subcarriers, an RB can also consist of other numbers of subcarriers.

[0112] In advanced LTE, as a method of allocating RBs to a terminal for the DL data channel (Physical Downlink Shared Channel, PDSCH), there is a method that uses a radio resource set called a resource block group (RBG) as a unit. As Figure 5 shown, each RBG consists of a continuous number of RBs (2 RBs in the Figure 5 example). In advanced LTE, the number of resource blocks (RBG size) P included in the RBG is configured according to the system bandwidth (for example, see NPL 5). For example, the base station can use a DL control signal (DCI) indicating a bitmap in units of RBGs to indicate the PDSCH resource allocation to the terminal. In this case, as the number of RBGs increases, the number of bits of the DL control signal also increases.

[0113] In this embodiment, the base station 100 and the terminal 200 determine the RBG size, which is a parameter of the virtual carrier and is a parameter applied to the PDSCH resource allocation. More specifically, the base station 100 and the terminal 200 determine the RBG size of the virtual carrier based on the bandwidth of the virtual carrier (i.e., the sum of the bandwidths of the first band and the segments).

[0114] Figure 6 Shows the flow of the RBG size determination process according to this embodiment.

[0115] The base station 100 indicates a synchronization signal (Primary Synchronization Signal (PSS) / Secondary Synchronization Signal (SSS)) or system information (Master Information Block (MIB) / System Information Block (SIB)) to the terminal 200 in a first frequency band (ST101).

[0116] The terminal 200 uses the first frequency band to obtain system information and performs a random access procedure or RRC connection control, etc. with the base station 100 (ST102).

[0117] For example, the base station 100 may use system information (e.g., MIB) to indicate information about the first frequency band (e.g., bandwidth) to the terminal 200. In addition, the base station 100 may use system information (e.g., SIB) or user-specific Radio Resource Control (RRC) signals to indicate information about a segment (additional frequency band) to the terminal 200. Note that the number of segments may be more than one.

[0118] Note that methods different from the above methods may be used to indicate information about the first frequency band and information about segments from the base station 100 to the terminal 200. For example, the base station 100 may use the MIB to indicate information about segments to the terminal 200. At this time, the MIB may be indicated to the terminal 200 using the first frequency band, or the MIB may be indicated to the terminal 200 using a segment. In addition, the base station 100 may indicate information about a virtual carrier to the terminal 200 (e.g., the sum of the bandwidths of the first frequency band and the segments). In addition, when the first frequency band and the segments are continuous in the frequency domain, the base station 100 may indicate information about a virtual carrier to the terminal 200 (e.g., the total bandwidth), and when the first frequency band and the segments are discontinuous in the frequency domain, the base station 100 may use system information (e.g., SIB) or user-specific RRC signals to indicate information about segments to the terminal 200 (e.g., bandwidth).

[0119] The base station 100 may use MAC signaling, RRC signals, or DL control signals (Downlink Control Information (DCI)) to indicate the configuration of segments (start and end of using segments) to the terminal 200.

[0120] Next, the base station 100 calculates the bandwidth of a virtual carrier, which is an extended frequency band including the first frequency band and the segment, based on information (bandwidth) about the first frequency band and information (bandwidth) about the segment (additional frequency band). The base station 100 then determines the RBG size of the virtual carrier based on the calculated bandwidth of the virtual carrier (ST103). Note that the method for determining the RBG size of the virtual carrier will be described in detail below.

[0121] As in the base station 100 (ST101), in ST101, the terminal 200 calculates the bandwidth of the virtual carrier (i.e., the sum of the bandwidths of the first frequency band and the segment) based on information (bandwidth) about the segment and information (bandwidth) about the first frequency band indicated by the base station 100. The terminal 200 then determines the RBG size of the virtual carrier based on the calculated bandwidth of the virtual carrier (ST104).

[0122] The base station 100 uses the determined RBG size to allocate resources for DL data (PDSCH) in the virtual carrier of the terminal 200 and sends DL resource allocation information and DL data (ST105). The terminal 200 identifies the allocated DL resources based on the determined RBG size and receives the DL data.

[0123] Figure 7 and Figure 8 shows an example of a method for determining the RBG size according to an embodiment.

[0124] Note that hereinafter, the relationship between the system bandwidth and the RBG similar to the relationship between the system bandwidth and the RBG size in LTE will be used as an example. More specifically, when the system bandwidth is not greater than 10 RBs, the RBG size P = 1; when the system bandwidth is between 11 RBs and 26 RBs, including 11 RBs and 26 RBs, the RBG size P = 2; when the system bandwidth is between 27 RBs and 63 RBs, including 27 RBs and 63 RBs, the RBG size P = 3; when the system bandwidth is between 64 RBs and 110 RBs, including 64 RBs and 110 RBs, the RBG size P = 4 (for example, see NPL 5). However, the relationship between the system bandwidth and the RBG size is not limited to being similar to the relationship in LTE. In addition, in LTE, for the RBG size, only a bandwidth of up to 20 MHz (110 RBs) is considered; but in NR, applications with a bandwidth greater than 20 MHz (e.g., 80 MHz) are considered, and thus, for broadband with a system bandwidth greater than 20 MHz, an RBG size greater than RBG size P = 4 can be used.

[0125] 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 frequency band) including the first frequency band and the segment, rather than the bandwidth of each of the first frequency band and the segment allocated to the terminal 200.

[0126] Figure 7 An example is shown where the first frequency band is 5 MHz (25 RBs) and the segment is 3 MHz (15 RBs). When data transmission and reception are performed separately in the Figure 7 first frequency band or segment shown, the RBG size of the first frequency band and segment is P = 2, corresponding to 25 RBs and 15 RBs respectively. At the same time, since Figure 7 the bandwidth of the virtual carrier shown in is 8 MHz (40 RBs), when using the virtual carrier for data transmission and reception, the RBG size is P = 3, corresponding to 40 RBs.

[0127] Figure 8 An example is shown where the first frequency band is 5 MHz (25 RBs) and the segment is 1.4 MHz (6 RBs). In the case of performing separate data transmission and reception in the Figure 8 first frequency band or segment shown, the RBG size of the first frequency band is P = 2, corresponding to 25 RBs, and the RBG size of the segment is P = 1, corresponding to 6 RBs. At the same time, since Figure 8 the bandwidth of the virtual carrier shown in is 6.4 MHz (31 RBs), when using the virtual carrier for data transmission and reception, the RBG size is P = 3, corresponding to 31 RBs.

[0128] More specifically, in Figure 7 and Figure 8 , compared with the case of determining the RBG size based on the individual bandwidths of the first frequency band and segment, the RBG size determined based on the virtual carrier including the first frequency band and segment becomes larger. Therefore, in all the bandwidths of the first frequency band and segment shown in Figure 7 or 8 (8 MHz or 6.4 MHz), determining the RBG size in units of the virtual carrier can reduce the total number of RBGs configured in the virtual carrier.

[0129] As described above, according to this embodiment, the base station 100 and the terminal 200 determine the RBG size of the virtual carrier, and the virtual carrier includes the first frequency band and segment as one unit. Therefore, the number of RBGs in the virtual carrier can be reduced, such that compared with the application of the RBG size in the case of using the first frequency band and segment separately, the number of bits required for resource allocation in the DL control signal (DCI) can be reduced, and the overhead of resource allocation can be reduced.

[0130] More specifically, according to this embodiment, for example, even in the case of applying the method of adding segments to a radio communication system that flexibly supports various bandwidths in advanced LTE or a radio communication system that can flexibly change the RF bandwidth of the terminal in NR, the parameters required for operations in the flexible bandwidth (here, the RBG size) can be appropriately determined.

[0131] (Variant of Embodiment 1)

[0132] In Variant 1, the base station 100 and the terminal 200 calculate the standard bandwidth that is the next larger (higher) bandwidth of the first frequency band, and determine the RBG size of the virtual carrier (second frequency band).

[0133] The term "standard bandwidth" herein refers to 1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz, and 20 MHz in advanced LTE. Note that the standard bandwidth is not limited to the above values, and another standard bandwidth may be defined.

[0134] For example, in Figure 9 , the standard bandwidth of the next larger (higher) bandwidth (10 MHz: 50 RBs) of the first frequency band is 15 MHz (75 RBs). Thus, the base station 100 and the terminal 200 determine that the RBG size of the first frequency band including 10 MHz and the segmented virtual carrier is P = 4, corresponding to 15 MHz.

[0135] Thus, for example, even when information (bandwidth) about the first frequency band and information (bandwidth) about the segmentation are separately indicated to the terminal 200, the terminal 200 can determine the RBG size of the virtual carrier according to the bandwidth of the first frequency band. More specifically, according to Variant 1, the RBG size determination method can be simplified.

[0136] (Variant 2 of Embodiment 1)

[0137] In Variant 2, the base station 100 and the terminal 200 calculate the standard bandwidth that is the minimum bandwidth among the standard bandwidths having a larger (higher) bandwidth than the bandwidth of the virtual carrier (second frequency band), and determine the RBG size of the virtual carrier.

[0138] For example, the standard bandwidth of the minimum bandwidth among the standard bandwidths having a larger (higher) bandwidth than the bandwidth of the virtual carrier (11.4 MHz (56 RBs)) shown in Figure 9 is 15 MHz (75 RBs). Thus, the base station 100 and the terminal 200 determine the RBG size of the virtual carrier as P = 4, corresponding to 15 MHz.

[0139] Thus, the base station 100 and the terminal 200 determine the RBG size of the virtual carrier to be similar to the standard bandwidth close to the bandwidth of the virtual carrier, so that the RBG size determination method can be simplified.

[0140] In addition, according to Variant 1 and Variant 2 of Embodiment 1, by configuring the bandwidth for resource allocation to be similar to the standard bandwidth for determining the RBG, the resource allocation area in the DCI can be the same as the standard bandwidth, so that the decoding of the DCI in the terminal 200 can be simplified.

[0141] (Embodiment 2)

[0142] Although the case of determining the RBG size of the virtual carrier (second band) based on the bandwidth of the virtual carrier was described in Embodiment 1, the case of determining the RBG size of the virtual carrier based on the RBG size of the first band (e.g., BCC) will be described in Embodiment 2.

[0143] When both a terminal that performs data transmission and reception using the first band and a terminal that performs data transmission and reception using the virtual carrier exist in the same resource, there is a possibility that the resource cannot be effectively used.

[0144] Figure 10 An example is shown in which the first band is 5 MHz (25 RBs) and the segment is 3 MHz (15 RBs). Note that in Figure 10 , as in Embodiment 1, it is assumed that the RBG is determined according to the system bandwidth.

[0145] In Figure 10 , when performing separate data transmission and reception using the first band or the segment, the RBG sizes of the first band and the segment are each P = 2. Meanwhile, the bandwidth of the virtual carrier is 8 MHz (40 RBs), such that when performing data transmission and reception using the virtual carrier, the RBG size of the virtual carrier is P = 3.

[0146] At this time, as Figure 10 shows, when both a terminal (hereinafter referred to as "Terminal #1") that performs data transmission and reception using the first band and a terminal (hereinafter referred to as "Terminal #2") that performs data transmission and reception using the virtual carrier exist, allocating RBG#2 (RB#3 and #4) to Terminal #1 makes it impossible to allocate RBG#1 (RB#1 to #3) and RBG#2 (RB#4 to #6) including RB#3 and #4 to Terminal #2. In other words, in Figure 10 , one RBG allocated to Terminal #1 is configured on the resources corresponding to two RBGs of Terminal #2, deteriorating the resource allocation efficiency of Terminal #2.

[0147] In this regard, in this embodiment, the RBG size of the virtual carrier is determined in consideration of the RBG size of the first band.

[0148] The base station and the terminal according to Embodiment 2 have the same basic configuration as the base station 100 and the terminal 200 according to Embodiment 1, and thus descriptions will be given in conjunction with Figure 3 and Figure 4 when.

[0149] Note that the method of indicating information (bandwidth) about the first frequency band and information (bandwidth) about the segmentation (additional frequency band) from the base station 100 to the terminal 200, and the method by which the base station 100 configures the segmentation (start and end used) for the terminal 200 are similar to the methods in Embodiment 1, and thus their descriptions will not be repeated hereinafter.

[0150] Based on the information (bandwidth) about the first frequency band and the information (bandwidth) about the segmentation (additional frequency band), the base station 100 according to this embodiment calculates the bandwidth of the virtual carrier (i.e., the sum of the bandwidths of the first frequency band and the segmentation). In addition, the terminal 200 calculates the bandwidth of the virtual carrier (second frequency band) based on the information (bandwidth) about the first frequency band and the information (bandwidth) about the segmentation indicated by the base station 100.

[0151] In addition, in this embodiment, the base station 100 and the terminal 200 determine the size of the RBG configured for the virtual carrier as X times the size of the RBG based on the frequency band configuration of the first carrier (assuming "X" is an integer equal to or greater than 2). Note that information about X can be indicated from the base station 100 to the terminal 200, or X can be a value defined by the standard.

[0152] Figure 11 An example of the method for determining the RBG size according to this embodiment is shown.

[0153] Figure 11 An example of the case where the first frequency band is 5 MHz (25 RBs) and the segmentation is 3 MHz (15 RBs) and the bandwidth of the virtual carrier is 8 MHz (40 RBs) is shown. When separate data transmission and reception are performed in the Figure 11 first frequency band or segmentation shown, the RBG sizes of the first frequency band and the segmentation are P = 2, corresponding to 25 RBs and 15 RBs respectively.

[0154] In Figure 11 , it is assumed that X = 2. Therefore, the RBG size in the case of performing data transmission and reception using the Figure 11 virtual carrier shown is P = 4, which is X times the RBG size P = 2 based on the bandwidth configuration of the first frequency band. In this way, the boundaries (ranges) between the RBGs configured for the virtual carrier are the same as the boundaries between the RBGs configured based on the bandwidth of the first frequency band. Therefore, the base station 100 can effectively perform resource allocation for the terminal 200 that performs data transmission and reception using the virtual carrier.

[0155] For example, in Figure 11In this case, it is assumed that when a terminal that performs data transmission and reception using a first frequency band and a terminal that performs data transmission and reception using a virtual carrier exist in the same resource, RBG #2 (RB #3 and #4) is allocated to the terminal that performs data transmission and reception using the first frequency band. In this case, the base station 100 cannot allocate RBG #1 (RB #1 to #4) including RB #3 and #4 to the terminal that performs data transmission and reception using the virtual carrier. In other words, although in the example shown in Figure 10 , due to one RBG allocated to the terminal that performs data transmission and reception using the first frequency band, the number of RBGs that cannot be allocated to the terminal that performs data transmission and reception using the virtual carrier is two, but in this embodiment ( Figure 11 ), the number of RBGs that cannot be allocated can be only one.

[0156] As described above, in this embodiment, the RBG size of the virtual carrier is configured as an integer multiple of the RBG size configured based on the bandwidth of the first frequency band, so that it is possible to prevent the RBGs allocated to the terminal that performs data transmission and reception using the first frequency band from being configured on multiple RBGs of the terminal that performs data transmission and reception using the virtual carrier. Therefore, it is possible to effectively multiplex the terminal that performs data transmission and reception using the first frequency band and the terminal that performs data transmission and reception using the virtual carrier.

[0157] In addition, according to this embodiment, an RBG size larger than the RBG size of the first frequency band can be configured for the virtual carrier. Therefore, as in Embodiment 1, when using the virtual carrier, compared with the case where the RBG size of the first frequency band is applied without any change, the number of RBGs of the virtual carrier can be reduced, so that the number of bits required for resource allocation in the DL control signal (DCI) can be reduced, and the overhead of resource allocation can be reduced.

[0158] (Embodiment 3)

[0159] In NR, as a method for covering terminals of services with different requirements, "hybrid parameter sets" have been studied, which allow signal waveforms with different subcarrier intervals, etc. to exist within the same frequency band. In addition, in NR, research has been conducted on configuring RBs with 12 subcarriers regardless of the subcarrier interval. In addition, in 3GPP, when FDM is applied to parameter sets with different subcarrier intervals, it has been agreed that the RB grid of the subcarrier interval adopts a "nested structure" as shown in Figure 12 . Note that the allocation of the RB numbers shown in Figure 12 is merely exemplary and is not limited to this example.

[0160] In addition, Figure 13An example of the RB grid is shown when terminals with subcarrier spacings of 15 kHz, 30 kHz, and 60 kHz are multiplexed. As Figure 13 shown, when terminals with different subcarrier spacings exist in a mixed manner, setting the RBG size to a power of 2 enables the alignment of the boundaries (ranges) between RBGs with the boundaries of the RB grid even between parameter sets with different subcarrier spacings. Therefore, resources can be effectively utilized in this case.

[0161] In this regard, in this embodiment, the RBG size of the virtual carrier is a power of 2.

[0162] The base station and terminal according to Embodiment 3 have the same basic configuration as the base station 100 and terminal 200 according to Embodiment 1, and thus will be described in conjunction with Figure 3 and Figure 4 herein.

[0163] Note that the method of indicating information (bandwidth) about the first frequency band from the base station 100 to the terminal 200 and information (bandwidth) about the segmentation (additional frequency band), and the method by which the base station 100 configures the segmentation (start and end used) for the terminal 200 are similar to the methods in Embodiment 1, and thus their descriptions will not be repeated hereinafter.

[0164] Based on the information (bandwidth) about the first frequency band and the information (bandwidth) about the segmentation (additional frequency band), the base station 100 according to this embodiment calculates the bandwidth of the virtual carrier (i.e., the sum of the bandwidths of the first frequency band and the segmentation). In addition, the terminal 200 calculates the bandwidth of the virtual carrier (second frequency band) based on the information (bandwidth) about the first frequency band and the information (bandwidth) about the segmentation indicated by the base station 100.

[0165] Furthermore, in this embodiment, the base station 100 and the terminal 200 determine a power of 2 as the RBG size configured for the virtual carrier. Note that the information about the RBG size (e.g., a power of 2; the value "n" of 2 n can be indicated from the base station 100 to the terminal 200, or a standard-defined value can be used. Additionally, as in Embodiment 1, the RBG size (e.g., a power of 2; the value "n" of 2 n can be calculated based on the bandwidth of the virtual carrier.

[0166] Figure 14 An example of the method for determining the RBG size according to this embodiment is shown.

[0167] Figure 14 An example is shown where the RBG size of the first frequency band with a 15 kHz subcarrier spacing is P = 2, and the RBG size of the virtual carrier with a 30 kHz subcarrier spacing is P = 2. In other words, in Figure 14In [the above], the RBG size of the virtual carrier is a power of 2. Therefore, the boundaries (ranges) between the RBGs configured for the virtual carrier are the same as the boundaries between the RBGs configured based on the bandwidth of the first frequency band. Thus, the base station 100 can effectively perform resource allocation for the terminal 200 that uses the virtual carrier to perform data transmission and reception.

[0168] For example, in Figure 14 assuming that when a terminal that uses the first frequency band to perform data transmission and reception and a terminal that uses the virtual carrier to perform data transmission and reception are both present in the same resource, RBG #2 (RB #3 and #4) is allocated to the terminal that uses the first frequency band to perform data transmission and reception. In this case, the base station 100 cannot allocate RBG #1 (RB #1 and #2) that includes the same resources as RB #3 and #4 to the terminal that uses the virtual carrier to perform data transmission and reception at a 15 kHz subcarrier spacing. In other words, as Figure 14 shown, the number of RBGs that cannot be allocated to the terminal that uses the virtual carrier to perform data transmission and reception can be only one.

[0169] As described above, in this embodiment, configuring the RBG size of the virtual carrier as a power of 2 enables the boundaries of the RBGs to be aligned with each other among the terminals even when terminals with different subcarrier spacings exist in a mixed manner. Thus, multiple terminals with different subcarrier spacings can be effectively multiplexed.

[0170] More specifically, according to this embodiment, for example, even when terminals with different subcarrier spacings exist in a mixed manner in a radio communication system that flexibly supports various bandwidths in advanced LTE or in a radio communication system that can flexibly change the RF bandwidth of a terminal in NR, the parameters (here, the RBG size) required for operations in the flexible bandwidth (e.g., the virtual carrier) can be appropriately determined.

[0171] (Embodiment 4)

[0172] The base station and the terminal according to Embodiment 4 have the same basic configuration as the base station 100 and the terminal 200 according to Embodiment 1, and thus a description will be given herein in combination with Figure 3 and Figure 4 when.

[0173] Note that the method of indicating the information (bandwidth) about the first frequency band and the information (bandwidth) about the segmentation (additional frequency band) from the base station 100 to the terminal 200 and the method by which the base station 100 configures the segmentation (start and end of use) for the terminal 200 are similar to the methods in Embodiment 1, and thus their descriptions will not be repeated hereinafter.

[0174] In this embodiment, a case will be described in which the configuration of the RBG size of the virtual carrier (second frequency band) is adaptively changed by signaling from the base station 100 to the terminal 200.

[0175] The control unit 101 of the base station 100 variably configures the RBG size of the virtual carrier, for example, according to the communication state of the terminal 200. For example, when it is necessary to multiplex a terminal that performs data transmission and reception using the first frequency band and a terminal that performs data transmission and reception using the virtual frequency band, the base station 100 determines the RBG size of the virtual carrier to be the same as the first frequency band, or an integer multiple of the first frequency band, or a power of 2 (for example, see Embodiment 2 and Embodiment 3). At the same time, when it is not necessary to multiplex a terminal that performs data transmission and reception using the first frequency band, the base station 100 may determine the RBG size of the virtual carrier to be a value other than an integer multiple of the first frequency band (or the same value as the first frequency band).

[0176] The base station 100 uses a high-layer control signal (for example, system information (MIB or SIB) or RRC signal) to indicate information about the RBG size of the virtual carrier (information about the configuration change) to the terminal 200.

[0177] The terminal 200 receives the high-layer control signal indicated by the base station 100 and identifies the RBG size of the virtual carrier based on the received high-layer control signal.

[0178] Figure 15 An example of the RBG size determination method according to this embodiment is shown. Figure 15 An example is shown in which the RBG size of the virtual carrier can be configured as P = 3 or P = 4.

[0179] For example, in Figure 15 , when a terminal that performs transmission and reception using the first frequency band with an RBG size P = 2 (for example, see Figure 10 ) and a terminal that performs transmission and reception using the virtual carrier exist in a mixed manner, the base station 100 may indicate an RBG size of P = 4 (or the second power of 2), which is twice the RBG size P = 2, to the terminal that performs transmission and reception using the virtual carrier, as shown in the lower figure of Figure 15 . Therefore, as in Embodiment 2 and Embodiment 3, the base station 100 can effectively multiplex a terminal that performs data transmission and reception using the first frequency band and a terminal that performs data transmission and reception using the virtual carrier.

[0180] At the same time, when there is no multiplexing of a terminal that performs data transmission and reception using the first frequency band and a terminal that performs data transmission and reception using the virtual carrier, the base station 100 may indicate an RBG size of P = 3 to the terminal that performs data transmission and reception using the virtual carrier. Therefore, for example, as in Embodiment 1 (see Figure 7)As described above, the RBG size is determined according to the bandwidth of the virtual carrier, and resource allocation can be flexibly performed while reducing the overhead for resource allocation.

[0181] As described above, according to this embodiment, the RBG size configured for the virtual carrier is variable and is indicated from the base station 100 to the terminal 200 by signaling (e.g., system information (MIB or SIB) or RRC signal). Thus, for example, depending on whether multiplexing of a terminal performing data transmission and reception using a first band and a terminal performing data transmission and reception using a virtual carrier is necessary, the RBG size with respect to the terminal 200 can be adaptively changed.

[0182] Note that even when the system information (e.g., MIB or SIB) indicates the RBG size, the terminal 200 can be reconfigured with the RBG size by an RRC signal.

[0183] Alternatively, when the RBG size is indicated by an RRC signal, the terminal 200 can use a default RBG size until the RRC signal is received. The default RBG size can be indicated by the system information or can be determined by a method similar to the methods in Embodiments 1 to 3.

[0184] (Embodiment 5)

[0185] In this embodiment, a method for determining RBs forming an RBG, which is a parameter for resource allocation applied to a DL data channel (PDSCH), will be described.

[0186] The base station and the terminal according to Embodiment 5 have the same basic configuration as the base station 100 and the terminal 200 according to Embodiment 1, and thus a description will be given herein in conjunction with Figure 3 and Figure 4 when.

[0187] Note that the method for indicating information (bandwidth) about the first band and information (bandwidth) about the segmentation (additional band) from the base station 100 to the terminal 200 and the method for the base station 100 to configure the segmentation (start and end used) for the terminal 200 are similar to the methods in Embodiment 1, and thus their descriptions will not be repeated hereinafter. Additionally, the RBG size determination method according to any one of Embodiments 1 to 4 can be used.

[0188] As described in Embodiments 1 to 4, when determining the RBG size while considering a band including a first band and a segmentation as one virtual carrier (second band), as Figure 16 shown, it is possible to configure an RBG including both the RBs of the first band and the RBs of the segmentation ( Figure 16 RBG#9 in). At this time, as Figure 16As shown, when the first frequency band and the segment are discontinuous in the frequency domain (when there is a gap in the frequency domain), multiple RBs with different channel states are regarded as one RBG (RBG#9). For this reason, the scheduling, precoding configuration, channel estimation accuracy, etc. of this RBG are negatively affected.

[0189] In this regard, in Embodiment 5, a description will be given of the case where the RBs forming one RBG include only the RBs of the first frequency band or only the RBs of the segment. In other words, in this embodiment, the base station 100 and the terminal 200 configure the RBG in such a way that the boundary (range) between the RBGs configured for the virtual carrier is consistent with the boundary between the first frequency band and the segment included in the virtual carrier.

[0190] Figure 17 An example of the RBG determination method according to this embodiment is shown. In Figure 17 , it is assumed that the RBG size P = 3.

[0191] In Figure 17 , the first frequency band and the segment are discontinuous in the frequency domain. Additionally, in Figure 17 , RBG#1 to #9 are composed of one or more RBs (RB#1 to #25) of the first frequency band, and RBG#10 to #14 are composed of the RBs (RB#1 to #15) of the segment.

[0192] As Figure 17 shown, near the boundary between the first frequency band and the segment in the virtual carrier, RBG#9 is composed of one RB (RB#25) of the first frequency band, while RBG#10 is composed of three RBs (RB#1 to #3) of the segment. More specifically, in Figure 17 , the boundary between the RBGs is at least consistent with the boundary between the first wave segment and the segment. In other words, in Figure 17 , there is no RBG composed of resource blocks of both the first frequency band and the segment that are discontinuous in the frequency domain. Therefore, since Figure 17 the RBs in each RBG shown are continuous in the frequency domain, their channel states are similar to each other.

[0193] Therefore, in this embodiment, even when the first frequency band and the segment are discontinuous in the frequency domain, the influence caused by the gap in the frequency domain on the scheduling, precoding configuration, channel estimation accuracy, etc. of the RBG configured in the virtual carrier can be suppressed.

[0194] (Embodiment 6)

[0195] In this embodiment, a method for determining the RBs forming the RBG, which is a parameter for resource allocation applied to the DL data channel (PDSCH), will be described.

[0196] When the first frequency band and the segment are discontinuous in the frequency domain, the influence of the gap in the frequency domain described in Embodiment 5 will occur.

[0197] Meanwhile, when the first frequency band and the segment are continuous in the frequency domain, rather than making the boundary between the RBGs coincide with the boundary between the first frequency band and the segment as in Embodiment 5, forming the RBGs without considering the boundary between the first frequency band and the segment can simplify the process and may reduce the number of RBGs. As a result, the number of bits required for resource allocation in the DCI can be reduced, and the overhead of resource allocation can be reduced.

[0198] In this regard, in Embodiment 6, a description will be given of the case where the configuration of the RBs forming the RBGs is adaptively changed.

[0199] The base station and the terminal according to Embodiment 6 have the same basic configuration as the base station 100 and the terminal 200 according to Embodiment 1, and thus will be described herein in combination with Figure 3 and Figure 4 when.

[0200] Note that the method of indicating the information (bandwidth) about the first frequency band and the information (bandwidth) about the segment (additional frequency band) from the base station 100 to the terminal 200, and the method by which the base station 100 configures the segment (start and end used) for the terminal 200 are similar to the methods in Embodiment 1, and thus their descriptions will not be repeated hereinafter. Additionally, the RBG size determination method according to any one of Embodiments 1 to 4 can be used.

[0201] Figure 18 An example of the RBG determination method according to this embodiment is shown. In Figure 18 it is assumed that the RBG size of the virtual carrier is P = 3.

[0202] When the first frequency band and the segment forming the virtual carrier are continuous in the frequency domain, the base station 100 (control unit 101) configures the RBGs without considering the boundary between the first frequency band and the segment. For example, as shown in the upper figure of Figure 18 there is an RBG#9 composed of the RBs of both the first frequency band and the segment, including the RB (RB#25) of the first frequency band and the RBs (RB#1 and #2) of the segment. Note that depending on the bandwidths of the first frequency band and the segment, it is possible that there is no RBG such as Figure 18 the RBG#9 in the upper figure that includes the RBs of both the first frequency band and the segment.

[0203] Meanwhile, when the first frequency band and the segment included in the virtual carrier are discontinuous in the frequency domain, the base station 100 (control unit 101) configures the RBGs in such a way that the boundary between the RBGs coincides with the boundary between the first frequency band and the segment, as in Embodiment 5. For example, as shown in Figure 18As shown in the following figure, each RBG consists of only one or more RBs of the first band, or only of segmented RBs, and there is no RBG consisting of both RBs of the first band and segmented RBs.

[0204] The base station 100 then uses a high-layer control signal (e.g., system information (MIB or SIB) or RRC signal) to indicate to the terminal 200 information about the boundary between RBGs of the virtual carrier (information about configuration changes).

[0205] The terminal 200 receives the high-layer control signal indicated by the base station 100 and identifies the RBG configuration (RBs forming the RBG) of the virtual carrier based on the received high-layer control signal.

[0206] Note that although the case where the RBG is adaptively configured by signaling from the base station 100 to the terminal 200 (e.g., system information (MIB or SIB) or RRC signal) has been described, the base station 100 and the terminal 200 can adaptively configure the RBG (one or more RBs forming the RBG) configured for the virtual carrier for the terminal 200 based on the relationship between the first band and the segments included in the virtual carrier in the frequency domain.

[0207] In the above description, the case where the RBG is configured according to whether the first band and the segments are continuous or discontinuous in the frequency domain has been described, but the method of configuring the RBG is not limited to these cases. For example, when the size of the gap between the first band and the segments in the frequency domain is at a level that does not cause any impact on scheduling, precoding configuration, channel estimation accuracy, etc. (e.g., not greater than a threshold), the RBG can be configured in a method similar to the method used when the first band and the segments are continuous in the frequency domain.

[0208] As described above, according to Embodiment 6, the RBG configuration is changed according to the contiguity of the first band and the segments forming the virtual carrier in the frequency domain. Therefore, while suppressing the influence of the gap in the frequency domain on the RBG according to the contiguity of the first band and the segments in the frequency domain, the overhead of resource allocation can also be reduced.

[0209] (Embodiment 7)

[0210] In Embodiments 1 to 6, the method of determining the RBG (RBG size), which is a parameter for resource allocation applied to the DL data channel (PDSCH), has been described. In contrast, in this embodiment, the method of determining the RBs forming a precoding group (PRG), which is another parameter for resource allocation applied to the PDSCH, will be described.

[0211] In advanced LTE technology, as a method for a terminal to configure precoding for PDSCH, there is a method that uses a radio resource set called a PRG as a unit. Similar to an RBG, each PRG consists of a continuous plurality of RBs. In advanced LTE technology, the number of RBs included in a PRG is determined according to the system bandwidth (for example, see NPL 5).

[0212] In this regard, in this embodiment, a method similar to the RBG size determination method described in Embodiments 1 to 4 is used to determine the PRG size. More specifically, in this embodiment, the PRG size can be determined by replacing "RBG" described in Embodiments 1 to 4 with "PRG".

[0213] The base station and the terminal according to Embodiment 7 have the same basic configuration as the base station 100 and the terminal 200 according to Embodiment 1, and thus will be described in conjunction with Figure 3 and Figure 4 at that time.

[0214] Note that the method for indicating information (bandwidth) about the first band and information (bandwidth) about the segmentation (additional band) from the base station 100 to the terminal 200, and the method for the base station 100 to configure the segmentation (start and end used) for the terminal 200 are similar to the methods in Embodiment 1, and thus their descriptions will not be repeated hereinafter.

[0215] More specifically, in the base station 100 according to this embodiment, the control unit 101 determines the parameters (here, the PRG size) of the virtual carrier composed of the first band and the segmentation that is an additional band of the first band, and the transmission unit 113 (corresponding to the transceiver unit) uses this parameter to communicate with the terminal 200 in the second band. Additionally, in the terminal 200 according to this embodiment, the control unit 208 determines the parameters (PRG size) of the virtual carrier composed of the first band and the segmentation that is an additional band of the first band, and the receiving unit 202 (corresponding to the transceiver unit) uses this parameter to communicate with the base station 100 in the second band.

[0216] Therefore, according to this embodiment, for example, even in the case of applying the method of adding segmentation to a radio communication system that flexibly supports various bandwidths in advanced LTE or a radio communication system that can flexibly change the RF bandwidth of a terminal in NR, the parameters (here, the PRG size) required for operations in the flexible bandwidth (for example, the virtual carrier) can be appropriately determined.

[0217] In addition, when determining the PRG size while considering the first frequency band and the segmented frequency band as a virtual carrier (second frequency band), it is possible to configure the PRG to include both the RBs of the first frequency band and the RBs of the segmentation. At this time, when the first frequency band and the segmentation are discontinuous in the frequency domain (when there is a gap in the frequency domain), multiple RBs with different channel states are regarded as one PRG. For this reason, the precoding configuration, channel estimation accuracy, etc. of predicting this PRG are negatively affected.

[0218] In this regard, in this embodiment, as Figure 19 shown, the RBs forming one PRG include only the RBs of the first frequency band or the RBs of the segmentation. In other words, in this embodiment, the base station 100 and the terminal 200 configure the PRG in such a way that the boundary (range) between the PRGs configured for the virtual carrier is consistent with the boundary between the first frequency band and the segmentation included in the virtual carrier.

[0219] For example, as Figure 19 shown, near the boundary between the first frequency band and the segmentation in the virtual carrier, PRG #9 consists of one RB (RB #25) of the first frequency band, and PRG #10 consists of three RBs (RB #1 to #3) of the segmentation. More specifically, in Figure 19 , the boundary between the PRGs is at least consistent with the boundary between the first frequency band and the segmentation. In other words, in Figure 19 , there is no PRG composed of the resource blocks of both the first frequency band and the segmentation that are discontinuous in the frequency domain. Therefore, since Figure 19 the RBs in each PRG shown are continuous in the frequency domain, their channel states are similar to each other.

[0220] Therefore, in this embodiment, even when the first frequency band and the segmentation are discontinuous in the frequency domain, the influence caused by the gap in the frequency domain on the precoding configuration, channel estimation accuracy, etc. of the PRG configured in the virtual carrier can be suppressed.

[0221] (Embodiment 8)

[0222] In this embodiment, a method for determining the RBs forming the PRG, which is a parameter for resource allocation applied to the DL data channel (PDSCH), will be described.

[0223] When the first frequency band and the segmentation are discontinuous in the frequency domain, the influence of the gap in the frequency domain described in Embodiment 7 will occur.

[0224] Meanwhile, when the first frequency band and the segment are continuous in the frequency domain, rather than making the boundary between PRGs coincide with the boundary between the first frequency band and the segment as in Embodiment 7, forming the PRG without considering the boundary between the first frequency band and the segment can simplify the process. For example, when configuring the PRG without considering the boundary between the first frequency band and the segment described in Embodiment 6 (e.g., Figure 18 the RBG in the upper figure of

[0225] ), the PRG allocation and precoding configuration can be simplified.

[0226] In this regard, in Embodiment 8, a case where the configuration of the RBs forming the PRG is adaptively changed will be described. Figure 3 and Figure 4 will be described herein in combination.

[0227] Note that the method of indicating information (bandwidth) about the first frequency band and information (bandwidth) about the segment (additional frequency band) from the base station 100 to the terminal 200 and the method by which the base station 100 configures the segment (start and end used) for the terminal 200 are similar to the methods in Embodiment 1, and thus their descriptions will not be repeated hereinafter. Additionally, the RBG size determination method according to any one of Embodiments 1 to 4 can be used. In other words, in this embodiment, the PRG size can be determined by replacing "RBG" described in Embodiments 1 to 4 with "PRG".

[0228] Figure 20 An example of the PRG determination method according to this embodiment is shown. In Figure 20 , it is assumed that the PRG size of the virtual carrier is 3 (3 RBs).

[0229] When the first frequency band and the segment forming the virtual carrier are continuous in the frequency domain, the base station 100 (control unit 101) configures the PRG without considering the boundary between the first frequency band and the segment. For example, as shown in the upper figure of Figure 20 , there is a PRG #9 composed of RBs of both the first frequency band and the segment, including the RB (RB #25) of the first frequency band and the RBs (RB #1 and #2) of the segment. Note that depending on the bandwidths of the first frequency band and the segment, it is possible that there is no PRG such as Figure 20 PRG #9 in the upper figure that includes RBs of both the first frequency band and the segment.

[0230] Meanwhile, when the first frequency band and segments included in the virtual carrier are discontinuous in the frequency domain, the base station 100 (control unit 101) configures the PRGs in such a way that the boundaries between the PRGs coincide with the boundaries between the first frequency band and the segments, as in Embodiment 7. For example, as Figure 20 shown in the following figure, each PRG consists of only one or more RBs of the first frequency band or RBs of the segments, and there is no PRG consisting of both RBs of the first frequency band and RBs of the segments.

[0231] The base station 100 then uses a higher layer control signal (e.g., system information (MIB or SIB) or RRC signal) to indicate to the terminal 200 information about the boundaries between the PRGs of the virtual carrier (information about configuration changes).

[0232] The terminal 200 receives the higher layer control signal indicated by the base station 100 and identifies the PRG configuration (RBs forming the PRGs) of the virtual carrier based on the received higher layer control signal.

[0233] Note that although the case where the PRGs are adaptively configured by signaling from the base station 100 to the terminal 200 (e.g., system information (MIB or SIB) or RRC signal) has been described, the base station 100 and the terminal 200 can adaptively configure the PRGs (one or more RBs forming the PRGs) configured for the virtual carrier for the terminal 200 based on the relationship between the first frequency band and the segments included in the virtual carrier in the frequency domain.

[0234] As described above, according to Embodiment 8, the configuration of the PRGs changes according to the continuity of the first frequency band and the segments forming the virtual carrier in the frequency domain. Therefore, while suppressing the influence of the gaps in the frequency domain on the PRGs according to the continuity of the first frequency band and the segments in the frequency domain, the processing can also be simplified.

[0235] (Embodiment 9)

[0236] In Embodiments 1 to 8, methods for determining the RBG or PRG, which are parameters applied to resource allocation of the DL data channel (PDSCH), have been described. In contrast, in this embodiment, a method for determining parameters required for a terminal to feedback channel state information (CSI) of a virtual carrier (second frequency band) to a base station will be described.

[0237] In advanced LTE, as CSI feedback information, there are a wideband channel quality indicator (CQI) and sub-band CQI. In CQI, the feedback bandwidth is wideband (the entire frequency band), and in sub-band CQI, the feedback bandwidth is in units of sub-bands. Each sub-band (which may be referred to as a "CSI sub-band") consists of a plurality of consecutive RBs, such as an RBG or a PRG. In advanced LTE, the number of RBs included in the CSI sub-band is determined according to the system bandwidth (for example, see NPL 5).

[0238] In this regard, in this embodiment, a method similar to the RBG size determination method described in Embodiments 1 to 4 is used to determine the CSI sub-band size. More specifically, in this embodiment, the CSI sub-band size can be determined by replacing "RBG" described in Embodiments 1 to 4 with "CSI sub-band".

[0239] The base station and the terminal according to Embodiment 9 have the same basic configuration as the base station 100 and the terminal 200 according to Embodiment 1, and thus will be described in conjunction with Figure 3 and Figure 4 when given.

[0240] Note that the method of indicating the information (bandwidth) about the first frequency band and the information (bandwidth) about the segmentation (additional frequency band) from the base station 100 to the terminal 200, and the method of the base station 100 configuring the segmentation (start and end used) for the terminal 200 are similar to the methods in Embodiment 1, and thus their descriptions will not be repeated hereinafter.

[0241] More specifically, in the base station 100 according to this embodiment, the control unit 101 determines the parameters of the virtual carrier (here, the CSI sub-band size) composed of the first frequency band and the segmentation as the additional frequency band of the first frequency band, and the receiving unit 115 (corresponding to the transceiver unit and including the extraction unit 117) uses this parameter to communicate with the terminal 200 in the second frequency band. In addition, in the terminal 200 according to this embodiment, the control unit 208 determines the parameters of the virtual carrier (CSI sub-band size) composed of the first frequency band and the segmentation as the additional frequency band of the first frequency band, and the transmitting unit 215 (corresponding to the transceiver unit and including the signal dispatching unit 213) uses this parameter to communicate with the base station 100 in the second frequency band.

[0242] Therefore, according to this embodiment, for example, even in the case of applying the method of adding segmentation to a radio communication system that flexibly supports various bandwidths in advanced LTE or a radio communication system that can flexibly change the RF bandwidth of a terminal in NR, the parameters (CSI sub-band size) required for operations in the flexible bandwidth (for example, the virtual carrier) can be appropriately determined.

[0243] In addition, when determining the CSI subbands when considering the first frequency band and the segmented frequency band as a virtual carrier (second frequency band), it is possible to configure the CSI subbands to include both the RBs of the first frequency band and the RBs of the segmentation. At this time, when the first frequency band and the segmentation are discontinuous in the frequency domain (when there is a gap in the frequency domain), multiple RBs with different channel states are regarded as one CSI subband. Therefore, even when using this CSI subband, it becomes difficult to perform high-accuracy CSI feedback.

[0244] In this regard, in this embodiment, as Figure 21 shown, the RBs forming one CSI subband include only the RBs of the first frequency band or only the RBs of the segmentation. In other words, in this embodiment, the base station 100 and the terminal 200 configure the CSI subbands in such a way that the boundary (range) between the CSI subbands configured for the virtual carrier coincides with the boundary between the first frequency band and the segmentation included in the virtual carrier.

[0245] For example, as Figure 21 shown, near the boundary between the first frequency band and the segmentation in the virtual carrier, CSI subband #9 consists of one RB (RB#25) of the first frequency band, and CSI subband #10 consists of 3 RBs (RB#1 to #3) of the segmentation. More specifically, in Figure 21 , the boundary between the CSI subbands coincides at least with the boundary between the first frequency band and the segmentation. In other words, in Figure 21 , there is no CSI subband composed of the resource blocks of both the first frequency band and the segmentation that are discontinuous in the frequency domain. Therefore, since Figure 21 the RBs in each CSI subband shown are continuous in the frequency domain, their channel states are similar to each other.

[0246] Therefore, in this embodiment, even when the first frequency band and the segmentation are discontinuous in the frequency domain, the influence of the gap in the frequency domain on the CSI feedback accuracy of using the CSI subbands configured in the virtual carrier can be suppressed.

[0247] Note that when the terminal 200 operates in the mode of using wideband CQI, the bandwidth of the wideband CQI can be configured in each of the first frequency band and the segmentation.

[0248] (Embodiment 10)

[0249] In this embodiment, a method for determining the RBs forming the CSI subbands, which are parameters required for the terminal to feedback the CSI of the virtual carrier to the base station, will be described.

[0250] When the first frequency band and the segmentation are discontinuous in the frequency domain, the influence of the gap in the frequency domain described in Embodiment 9 appears.

[0251] Meanwhile, when the first band and the segment are continuous in the frequency domain, rather than making the boundary between CSI sub-bands coincide with the boundary between the first band and the segment as in Embodiment 9, forming CSI sub-bands without considering the boundary between the first band and the segment can simplify the processing.

[0252] In this regard, in Embodiment 10, a description will be given of a case where the configuration of RBs forming CSI sub-bands is adaptively changed.

[0253] The base station and the terminal according to Embodiment 10 have the same basic configuration as the base station 100 and the terminal 200 according to Embodiment 1, and thus will be described herein in conjunction with Figure 3 and Figure 4 when given.

[0254] Note that the method of indicating information (bandwidth) about the first band and information (bandwidth) about the segment (additional band) from the base station 100 to the terminal 200, and the method by which the base station 100 configures the segment (start and end used) for the terminal 200 are similar to the methods in Embodiment 1, and thus their descriptions will not be repeated hereinafter. In addition, the method for determining the RBG size according to any one of Embodiments 1 to 4 can be used for the method for determining the CSI sub-band size. More specifically, in this embodiment, the CSI sub-band size can be determined by replacing "RBG" described in Embodiments 1 to 4 with "CSI sub-band".

[0255] Figure 22 An example of the CSI sub-band determination method according to this embodiment is shown. In Figure 22 , it is assumed that the CSI sub-band size of the virtual carrier is 3 (3 RBs).

[0256] When the first band and the segment are continuous in the frequency domain, the base station 100 (control unit 101) configures the CSI sub-bands without considering the boundary between the first band and the segment. For example, as shown in the upper figure of Figure 22 , there is a CSI sub-band #9 composed of RBs of both the first band and the segment, including the RB (RB#25) of the first band and the RBs (RB#1 and #2) of the segment. Note that depending on the bandwidths of the first band and the segment, it is possible that there is no CSI sub-band such as Figure 22 the CSI sub-band #9 in the upper figure of containing RBs of both the first band and the segment.

[0257] Meanwhile, when the first band and the segment included in the virtual carrier are not continuous in the frequency domain, the base station 100 (control unit 101) configures the CSI sub-bands in such a way that the boundary between CSI sub-bands coincides with the boundary between the first band and the segment, as in Embodiment 9. For example, as inFigure 22 As shown in the figure below, each CSI sub-band consists of only one or more RBs of the first band, or only of segmented RBs, and there is no CSI sub-band consisting of both RBs of the first band and segmented RBs.

[0258] The base station 100 then uses a high-layer control signal (e.g., system information (MIB or SIB) or RRC signal) to indicate to the terminal 200 information about the boundaries between CSI sub-bands of the virtual carrier (information about configuration changes).

[0259] The terminal 200 receives the high-layer control signal indicated by the base station 100 and identifies the CSI sub-band configuration (RBs forming the CSI sub-band) of the virtual carrier based on the received high-layer control signal.

[0260] Note that although the case where the CSI sub-band is adaptively configured by signaling from the base station 100 to the terminal 200 (e.g., system information (MIB or SIB) or RRC signal) has been described, the base station 100 and the terminal 200 can adaptively configure, for the terminal 200, the CSI sub-bands configured for the virtual carrier (one or more RBs forming the CSI sub-band) based on the relationship between the first band and the segments included in the virtual carrier in the frequency domain.

[0261] As described above, according to Embodiment 10, the configuration of the CSI sub-band changes according to the continuity of the first band and the segments forming the virtual carrier in the frequency domain. Therefore, while suppressing the influence of the gap in the frequency domain on the CSI feedback accuracy according to the continuity of the first band and the segments in the frequency domain, the processing can also be simplified.

[0262] (Embodiment 11)

[0263] In Embodiments 1 to 10, the method of determining the RBG or PRG as a parameter for resource allocation applied to the DL data channel (PDSCH) or the CSI feedback sent from the terminal to the base station has been described. In contrast, in this embodiment, the method of determining the parameters required for the terminal to send the SRS of the virtual carrier (second band) to the base station will be described.

[0264] In advanced LTE, the terminal can send the SRS as a reference signal for UL channel quality measurement. Regarding the SRS transmission method, there are wideband SRS and sub-band SRS. In wideband SRS, the bandwidth is wideband (the entire band), and in sub-band SRS, the bandwidth is in units of sub-bands. Each sub-band (which can be referred to as an "SRS sub-band") consists of a plurality of consecutive RBs, like an RBG, PRG, or CSI sub-band. In advanced LTE, the number of RBs included in the SRS sub-band is determined according to the system bandwidth (e.g., see NPL 6).

[0265] In this regard, in this embodiment, a method similar to the RBG size determination method described in Embodiments 1 to 4 is used to determine the SRS sub-band size. More specifically, in this embodiment, the SRS sub-band size can be determined by replacing "RBG" described in Embodiments 1 to 4 with "SRS sub-band".

[0266] The base station and the terminal according to Embodiment 11 have the same basic configuration as the base station 100 and the terminal 200 according to Embodiment 1, and thus will be described in conjunction with Figure 3 and Figure 4 at that time.

[0267] Note that the method of indicating the information (bandwidth) about the first band and the information (bandwidth) about the segmentation (additional band) from the base station 100 to the terminal 200 and the method by which the base station 100 configures the segmentation (start and end used) for the terminal 200 are similar to the methods in Embodiment 1, and thus their descriptions will not be repeated hereinafter.

[0268] More specifically, in the base station 100 according to this embodiment, the control unit 101 determines the parameters of the virtual carrier (the SRS sub-band size herein) composed of the first band and the segmentation that is an additional band of the first band, and the receiving unit 115 (corresponding to the transceiver unit and including the extraction unit 117) uses this parameter to communicate with the terminal 200 in the second band. Additionally, in the terminal 200 according to this embodiment, the control unit 208 determines the parameters (SRS sub-band size) of the virtual carrier composed of the first band and the segmentation that is an additional band of the first band, and the transmitting unit 215 (corresponding to the transceiver unit and including the signal dispatching unit 213) uses this parameter to communicate with the base station 100 in the second band.

[0269] Therefore, according to this embodiment, for example, even in the case of applying the method of adding segmentation to a radio communication system that flexibly supports various bandwidths in advanced LTE or a radio communication system that can flexibly change the RF bandwidth of a terminal in NR, the parameters (the SRS sub-band size herein) required for operations in the flexible bandwidth (e.g., virtual carrier) can be appropriately determined.

[0270] Furthermore, when determining the SRS sub-band when considering the band including the first band and the segmentation as one virtual carrier (second band), it is possible to configure the SRS sub-band including both the RBs of the first band and the RBs of the segmentation. At this time, when the first band and the segmentation are discontinuous in the frequency domain (when there is a gap in the frequency domain), multiple RBs with different channel states are regarded as one SRS sub-band. For this reason, even when using this SRS sub-band, it becomes difficult for the base station 100 to perform accurate channel quality measurement.

[0271] In this regard, in this embodiment, as Figure 23 shown, the RBs forming an SRS sub-band include only the RBs of the first band or only the segmented RBs. In other words, in this embodiment, the base station 100 and the terminal 200 configure the SRS sub-band in such a way that the boundary (range) between the SRS sub-bands configured for the virtual carrier coincides with the boundary between the first band and the segmentation included in the virtual carrier.

[0272] For example, as Figure 23 shown, near the boundary between the first band and the segmentation in the virtual carrier, the SRS sub-band #9 consists of one RB (RB#25) of the first band, and the CSI sub-band #10 consists of three segmented RBs (RB#1 to #3). More specifically, in Figure 23 it, the boundary between the SRS sub-bands coincides at least with the boundary between the first band and the segmentation. In other words, in Figure 23 it, there is no SRS sub-band composed of resource blocks of both the discontinuous first band and the segmentation in the frequency domain. Therefore, since Figure 23 the RBs in each SRS sub-band shown in

[0273] are continuous in the frequency domain, their channel states are similar to each other.

[0274] Note that when the terminal 200 operates in the mode using the wideband SRS, the bandwidth of the wideband SRS can be configured in each of the first band and the segmentation.

[0275] (Embodiment 12)

[0276] In this embodiment, a method for determining the RBs forming the SRS sub-band, which is a parameter required for the terminal to transmit the SRS of the virtual carrier to the base station, will be described.

[0277] When the first band and the segmentation are discontinuous in the frequency domain, the influence of the gap in the frequency domain described in Embodiment 11 will occur.

[0278] At the same time, when the first band and the segmentation are continuous in the frequency domain, instead of making the boundary between the SRS sub-bands coincide with the boundary between the first band and the segmentation as in Embodiment 11, forming the SRS sub-band without considering the boundary between the first band and the segmentation can simplify the process.

[0279] In this regard, in Embodiment 12, a description will be given of the case where the configuration of the RBs forming the SRS sub-band is adaptively changed.

[0280] The base station and the terminal according to Embodiment 12 have the same basic configuration as the base station 100 and the terminal 200 according to Embodiment 1, and thus will be described herein in conjunction with Figure 3 and Figure 4 when given.

[0281] Note that the method of indicating information (bandwidth) about the first frequency band from the base station 100 to the terminal 200 and information (bandwidth) about the segmentation (additional frequency band), and the method by which the base station 100 configures the segmentation (start and end used) for the terminal 200 are similar to those in Embodiment 1, and thus their descriptions will not be repeated hereinafter. Additionally, the method for determining the RBG size according to any one of Embodiments 1 to 4 can be used for the method of determining the SRS sub-band size. More specifically, in this embodiment, the SRS sub-band size can be determined by replacing "RBG" described in Embodiments 1 to 4 with "SRS sub-band".

[0282] Figure 24 An example of the method for determining the SRS sub-band according to this embodiment is shown. In Figure 24 , it is assumed that the SRS sub-band size of the virtual carrier is 3 (3 RBs).

[0283] When the first frequency band and the segmentation are continuous in the frequency domain, the base station 100 (control unit 101) configures the SRS sub-band without considering the boundary between the first frequency band and the segmentation. For example, as shown in the upper figure of Figure 24 , there is an SRS sub-band #9 composed of RBs of both the first frequency band and the segmentation, including the RB (RB#25) of the first frequency band and the RBs (RB#1 and #2) of the segmentation. Note that depending on the bandwidths of the first frequency band and the segmentation, it is possible that there is no SRS sub-band such as Figure 24 the SRS sub-band #9 in the upper figure of which contains RBs of both the first frequency band and the segmentation.

[0284] Meanwhile, when the first frequency band and the segmentation included in the virtual carrier are not continuous in the frequency domain, the base station 100 (control unit 101) configures the SRS sub-band in such a way that the boundary between the SRS sub-bands coincides with the boundary between the first frequency band and the segmentation, as in Embodiment 11. For example, as shown in the lower figure of Figure 24 , each SRS sub-band is composed of only one or more RBs of the first frequency band or only of the RBs of the segmentation, and there is no SRS sub-band composed of both the RBs of the first frequency band and the RBs of the segmentation.

[0285] The base station 100 then uses a high-layer control signal (e.g., system information (MIB or SIB) or RRC signal) to indicate to the terminal 200 information about the boundary between SRS sub-bands of the virtual carrier (information about configuration changes).

[0286] The terminal 200 receives the high-layer control signal indicated by the base station 100 and identifies the SRS sub-band configuration of the virtual carrier (RBs forming the SRS sub-bands) based on the received high-layer control signal.

[0287] Note that although the case where the SRS sub-bands are adaptively configured by signaling from the base station 100 to the terminal 200 (e.g., system information (MIB or SIB) or RRC signal) has been described, the base station 100 and the terminal 200 can adaptively configure for the terminal 200 the SRS sub-bands configured for the virtual carrier (one or more RBs forming the SRS sub-bands) based on the relationship between the first band and segments included in the virtual carrier in the frequency domain.

[0288] As described above, according to Embodiment 12, the configuration of the SRS sub-bands changes according to the continuity of the first band and segments forming the virtual carrier in the frequency domain. Therefore, while suppressing the influence of gaps in the frequency domain on the channel quality measurement accuracy in the base station 100 according to the continuity of the first band and segments in the frequency domain, the processing can also be simplified.

[0289] So far, each embodiment of the present disclosure has been described.

[0290] Note that in Embodiments 5 to 12, a method has been described for making the boundary between RBG, PRG, CSI sub-bands, or SRS sub-bands coincide with the boundary between the first band and segments when the first band and segments are discontinuous in the frequency domain with respect to these parameters. However, when the first band and segments are continuous in the frequency domain, the RBG, PRG, CSI sub-bands, or SRS sub-bands can be configured without considering the boundary between the first band and segments. In this case, for example, regarding the PRG, in the PRG composed of the RBs of the first band and the RBs of the segments (e.g., Figure 20 PRG#9 in the upper figure above), different precodings can be applied to the RBs in the same PRG ( Figure 20 RB#25 as well as RB#1 and RB#2 in PRG#9 in the upper figure above). Additionally, regarding the CSI sub-bands and SRS sub-bands, the terminal 200 can discard the transmission of the CSI sub-band composed of the RBs of the first band and the RBs of the segments (e.g., Figure 22 CSI sub-band #9 in the upper figure above) and the SRS sub-band composed of it ( Figure 24 SRS sub-band #9 in the upper figure above).

[0291] The present disclosure can be implemented by software, hardware, or software in cooperation with hardware. Each functional block used in the description of each of the above embodiments can be implemented in part or in whole by an LSI such as an integrated circuit, and each process described in each embodiment can be controlled in part or in whole by the same LSI or a combination of LSIs. The LSI can be formed as a single chip, or can be formed as a single chip to include some or all of the functional blocks. The LSI can include data input and output coupled thereto. Depending on the degree of integration, the LSI herein can be referred to as an IC, a system LSI, a super LSI, or an ultra LSI. However, the technology for implementing integrated circuits is not limited to LSIs, and can be implemented by using dedicated circuits, general-purpose processing units, or dedicated processing units. In addition, a field programmable gate array (FPGA) can be used, which can be programmed after the LSI is manufactured, or a reconfigurable processing unit can be used, in which the connections and settings of the circuit units provided inside the LSI can be reconfigured. The present disclosure can be implemented as digital processing or analog processing. If, due to the progress of semiconductor technology or other derivative technologies, future integrated circuit technologies replace LSIs, then future integrated circuit technologies can be used to integrate the functional blocks. Biotechnology can also be applied.

[0292] A base station according to the present disclosure includes: a circuit that determines parameters for a frequency band composed of a first frequency band and segments that are additional frequency bands of the first frequency band, and the frequency band composed of the first frequency band and the segments is referred to as a second frequency band; and a transceiver unit that communicates with a terminal in the second frequency band using the parameters.

[0293] In the base station according to the present disclosure, the parameter is a resource block group (RBG) size configured in the second frequency band, and the circuit determines the RBG size based on the bandwidth of the second frequency band.

[0294] In the base station according to the present disclosure, the parameter is a resource block group (RBG) size configured in the second frequency band, and the circuit determines the RBG size in the second frequency band as X times the RBG size configured based on the bandwidth of the first frequency band (assuming X is an integer equal to or greater than 2).

[0295] In the base station according to the present disclosure, the parameter is a resource block group (RBG) size configured in the second frequency band, and the circuit determines the RBG size as a power of 2.

[0296] In the base station according to the present disclosure, the RBG size is variable, and the RBG size is indicated from the base station to the terminal.

[0297] In the base station according to the present disclosure, the circuit configures the RBG such that the boundary between multiple RBGs configured in the second frequency band coincides with the boundary between the first frequency band and the segments.

[0298] The terminal according to the present disclosure includes: a circuit that determines parameters for a frequency band composed of a first frequency band and segments that are additional frequency bands of the first frequency band, and the frequency band composed of the first frequency band and the segments is referred to as a second frequency band; and a transceiver unit that communicates with a base station in the second frequency band using the parameters.

[0299] The communication method according to the present disclosure includes: determining parameters for a frequency band composed of a first frequency band and segments that are additional frequency bands of the first frequency band, and the frequency band composed of the first frequency band and the segments is referred to as a second frequency band; and communicating with a terminal in the second frequency band using the parameters.

[0300] The communication method according to the present disclosure includes: determining parameters for a frequency band composed of a first frequency band and segments that are additional frequency bands of the first frequency band, and the frequency band composed of the first frequency band and the segments is referred to as a second frequency band; and communicating with a base station in the second frequency band using the parameters.

[0301] Industrial applications

[0302] Aspects of the present disclosure are useful in mobile communication systems.

[0303] List of reference symbols

[0304] 100 Base station

[0305] 101, 208 Control unit

[0306] 102 Data generation unit

[0307] 103, 106, 109, 210 Encoding unit

[0308] 104, 107, 110, 211 Modulation unit

[0309] 105 Upper layer control signal generation unit

[0310] 108 DL control signal generation unit

[0311] 111, 213 Signal distribution unit

[0312] 112, 214 IFFT processing unit

[0313] 113, 215 Transmission unit

[0314] 114, 201 Antenna

[0315] 115, 202 Reception unit

[0316] 116, 203 FFT processing unit

[0317] 117, 204 Extraction unit

[0318] 118 CSI Demodulation Unit

[0319] 119 SRS Measurement Unit

[0320] 205 DL Control Signal Demodulation Unit

[0321] 206 Upper Layer Control Signal Demodulation Unit

[0322] 207 DL Data Signal Demodulation Unit

[0323] 209 CSI Generation Unit

[0324] 212 SRS Generation Unit

Claims

1. A communication device, characterized in that, Comprising: A circuit that determines the number of resource blocks forming a resource block group, where the resource block group is a unit for allocating resources to the communication device in a first frequency band or a second frequency band, and where the second frequency band is an extended frequency band extended from the first frequency band; and A transceiver that communicates with a base station using the resources, In the communication device, one of the number of resource blocks determined for the first frequency band and the number of resource blocks determined for the second frequency band is an integer multiple of the other, the subcarrier spacing in the first frequency band and the subcarrier spacing in the second frequency band can be respectively configured, and the number of resource blocks set for the first frequency band and the number of resource blocks set for the second frequency band are powers of 2.

2. The communication device according to claim 1, wherein, Determine the number of resource blocks for the first frequency band based on the bandwidth of the first frequency band, and determine the number of resource blocks for the second frequency band based on the bandwidth of the second frequency band.

3. The communication device according to claim 1, wherein, Determine the number of resource blocks for the second frequency band based on the bandwidth of the second frequency band rather than based on the bandwidth of the first frequency band.

4. The communication device according to claim 1, wherein, The subcarrier spacing in the second frequency band is different from the subcarrier spacing in the first frequency band.

5. The communication device according to claim 4, wherein, The number of subcarriers forming one resource block is 12, regardless of the subcarrier spacing.

6. The communication device according to claim 1, wherein, The transceiver receives information related to the number of resource blocks forming the resource block group from the base station.

7. The communication device according to claim 1, wherein, The transceiver receives information related to the bandwidth of the first frequency band and information related to the bandwidth of the second frequency band from the base station.

8. The communication device according to claim 1, wherein, The transceiver receives control information from the base station in the first frequency band and receives data from the base station in the second frequency band.

9. A communication method, characterized in that, Comprising the following steps: Determine the number of resource blocks forming a resource block group, where the resource block group is a unit for allocating resources to a terminal in a first frequency band or a second frequency band, and where the second frequency band is an extended frequency band extended from the first frequency band; and Communicate with a base station using the resources, In the communication method, one of the number of resource blocks determined for the first frequency band and the number of resource blocks determined for the second frequency band is an integer multiple of the other, the subcarrier spacing in the first frequency band and the subcarrier spacing in the second frequency band can be respectively configured, and the number of resource blocks set for the first frequency band and the number of resource blocks set for the second frequency band are powers of 2.

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