Terminal device and wireless communication method

Abstract

A terminal device (10) in a mobile communication system (100) that supports carrier aggregation, the terminal device (10) comprising: a reception unit (11) for receiving, from a base station device (50), an inquiry relating to capability information pertaining to the terminal device (10); a notification unit (13) for notifying the base station device (50), in response to the inquiry, about a simultaneously transmittable count serving as capability information, the simultaneously transmittable count relating to the number of bands that can be simultaneously transmitted in carrier aggregation; and a transmission unit (15) for dynamically changing the bands on the basis of wireless resources allocated from the base station device (50) and transmitting data. This makes it possible to provide wireless communication technology for improving the usage efficiency of wireless communication resources between the terminal device (10) and the base station device (50).

Description

[Technical Field]

[0001] The present invention relates to a terminal device and a wireless communication method. [Background technology]

[0002] The international standardization organization 3GPP (Third Generation Partnership Project) is currently studying New Radio (NR), a new radio access technology for fifth-generation (5G) cellular communication systems. NR is being considered as a technology that will enable a wider variety of services than the fourth-generation cellular communication system, Long Term Evolution (LTE)-Advanced. For example, NR defines requirements for different usage scenarios, such as enhanced Mobile Broadband (eMBB) for high-speed, high-capacity communication, Ultra-Reliable and Low Latency Communication (URLLC) for ultra-reliable, low-latency communication, and massive Machine Type Communication (mMTC) for simultaneous connection of multiple Internet of Things (IoT) devices.

[0003] NR employs carrier aggregation (CA), which enables bandwidth expansion by aggregating multiple frequency bands, for example, 20 MHz, called component carriers (CC) (see Non-Patent Document 1).

[0004] Meanwhile, NR employs antenna technology to improve the throughput of wireless communication. For example, NR enables wireless communication using millimeter waves. Implementing wireless communication using a relatively high frequency band such as millimeter waves increases propagation loss and other problems. To prevent such problems, a technology known as beamforming is used to form beams with a relatively narrow beam width. NR also employs MIMO (Multiple Input Multiple Output), a technology in which both the transmitting and receiving sides are equipped with multiple antennas and transmit data in parallel by dividing it among the multiple antennas (see Non-Patent Document 2).

[0005] Furthermore, in the data transmission process that combines uplink CA of two bands (frequency bands) and MIMO, DS (Dynamic switching) is adopted, that is, a technology that dynamically changes the two bands over time to transmit data (see Non-Patent Document 2). [Prior art documents] [Patent documents]

[0006] [Non-Patent Document 1] 3GPP standard document “TS 38.306 Ver.16.5.0” [Non-patent document 2] 3GPP standard document “TS 38.331 Ver.16.5.0” Summary of the Invention [Problem to be solved by the invention]

[0007] In conventional DS, the number of simultaneous transmissions, which is the number of bands that can be transmitted simultaneously, is assumed to be two in uplink CA of a terminal device. Furthermore, in NR, there is no mechanism for a base station device to check the number of simultaneous transmissions that a terminal device can transmit. If a base station device communicates with a terminal device that can transmit only one simultaneous transmission, it cannot perform appropriate scheduling according to the number of simultaneous transmissions that the terminal device can transmit. Therefore, there is a risk that the utilization efficiency of wireless communication resources between the terminal device and the base station device will decrease.

[0008] The present invention has been made in view of the above circumstances, and has an object to provide a wireless communication technique for improving the utilization efficiency of wireless communication resources between a terminal device and a base station device. [Means for solving the problem]

[0009] A terminal device according to one aspect of the present invention is a terminal device in a mobile communication system compatible with carrier aggregation, and includes a receiving unit that receives an inquiry regarding capability information of the terminal device from a base station device, a notification unit that, in response to the inquiry, notifies the base station device of a simultaneous transmission number regarding the number of bands that can be transmitted simultaneously in carrier aggregation as capability information, and a transmitting unit that dynamically changes the band based on radio resources allocated by the base station device and transmits a radio signal.

[0010] A wireless communication method according to one aspect of the present invention is a wireless communication method used by a terminal device in a mobile communication system that supports carrier aggregation, and includes the steps of receiving an inquiry regarding capability information of the terminal device from a base station device, notifying the base station device of a simultaneous transmission number regarding the number of bands that can be transmitted simultaneously in carrier aggregation as capability information in response to the inquiry, and dynamically changing the band based on radio resources allocated from the base station device and transmitting a radio signal. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a wireless communication technique for improving the utilization efficiency of wireless communication resources between a terminal device and a base station device. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing an example of a schematic configuration of a mobile communication system according to an embodiment. [Figure 2] FIG. 2 is a configuration diagram showing an example of the hardware configuration of a terminal device and a base station device in an embodiment. [Figure 3] FIG. 3 is a configuration diagram illustrating an example of a functional block configuration of a terminal device according to an embodiment. [Figure 4] FIG. 4 is a configuration diagram illustrating an example of a functional block configuration of a base station device according to an embodiment. [Figure 5] FIG. 5 is a flowchart illustrating an example of a wireless signal transmission process of a terminal device according to an embodiment. [Figure 6] FIG. 6 is a conceptual diagram showing an example of a transmission process of terminal capability information ("UECapabilityInformation"). [Figure 7] FIG. 7 is a conceptual diagram showing an example of a process for transmitting terminal capability information. [Figure 8] FIG. 8 is a conceptual diagram showing an example of a process for transmitting terminal capability information. [Figure 9] FIG. 9 is a conceptual diagram showing an example of a process for transmitting terminal capability information. [Figure 10] FIG. 10 is a conceptual diagram showing an example of a process for transmitting terminal capability information. [Figure 11] FIG. 11 is a conceptual diagram showing an example of a process for transmitting terminal capability information. [Figure 12] FIG. 12 is a conceptual diagram illustrating an example of dynamic switching (DS) processing of a terminal device in one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] An embodiment of the present invention will be described below. In the following description of the drawings, identical or similar parts are denoted by identical or similar reference numerals. However, the drawings are schematic. Therefore, specific dimensions and the like should be determined in light of the following description. Furthermore, it goes without saying that the drawings include parts with different dimensional relationships and ratios. Furthermore, the technical scope of the present invention should not be interpreted as being limited to the embodiment.

[0014] A schematic configuration of a mobile communication system compatible with carrier aggregation (CA) in one embodiment will be described with reference to Fig. 1. Carrier aggregation processing refers to processing that enables bandwidth expansion by aggregating (bundling) multiple frequency bands, for example, 20 MHz, called component carriers (CC). Fig. 1 is a configuration diagram showing an example of a schematic configuration of a mobile communication system 100 in one embodiment.

[0015] As shown in Fig. 1, mobile communication system 100 includes terminal device 10-1 to terminal device 10-m, base station device 50-1 to base station device 50-n, and core network device 90. Note that Fig. 1 illustrates terminal device 10-1 to terminal device 10-m as m terminal devices (m is an integer equal to or greater than 2).

[0016] In the following description, when these m terminal devices are described without distinction, some of the reference numerals are omitted and they are simply referred to as "terminal device 10." Also, in FIG. 1, n base station devices (n is an integer of 2 or more) are illustrated as base station device 50-1 to base station device 50-n. In the following description, when these n base station devices are described without distinction, some of the reference numerals are omitted and they are simply referred to as "base station device 50."

[0017] Here, an overview of a mobile communication system 100 according to one embodiment of the present invention will be described below. As described above, in NR, DS processing is adopted in radio signal transmission processing that combines uplink CA and MIMO in two bands (frequency bands).

[0018] 12 is a conceptual diagram showing an example of DS processing of a terminal device in one embodiment. A terminal device in a mobile communication system compatible with carrier aggregation illustratively includes a signal processing unit 241 that performs baseband signal processing, RF (Radio Frequency) front ends 243A and 243B that perform processing related to, for example, an amplifier and radio signals, and an antenna 27 that can emit (radiate) and receive radio waves (electromagnetic waves) in one or more predetermined frequency bands.

[0019] As an example of DS processing, in the terminal device's uplink CA, the terminal device transmits radio signals while dynamically changing the number of bands that can be transmitted simultaneously, which is the number of bands that can be transmitted simultaneously, from 2. For example, the terminal device dynamically switches between Case 2, in which two bands in frequency B are used simultaneously, and Case 1, in which one band in frequency A and one band in frequency B are used simultaneously.

[0020] When switching from Case 2 to Case 1, the terminal device dynamically switches from the RF front end 243A in frequency B to the RF front end 243 in frequency A. Note that the terminal device can dynamically switch from Case 1 to Case 2 as a DS process, in addition to dynamically switching from Case 2 to Case 1. Note that the method of dynamically switching from Case 1 to Case 2 and from Case 2 to Case 1 is arbitrary, but the dynamic switching of Cases may be performed based on at least one of, for example, a change in the communication status between the terminal device and the base station device, the tightness of radio resources in each frequency of the base station device, and the passage of a predetermined time.

[0021] In conventional DS, the number of bands that can be transmitted simultaneously in the uplink CA of a terminal device is assumed to be 2. In other words, conventional DS does not assume that the number of bands that can be transmitted simultaneously is other than 2.

[0022] Furthermore, in NR, there is no mechanism for a base station device to check the number of simultaneous transmissions that a terminal device can perform. Therefore, even if a base station device communicates with a terminal device that can perform simultaneous transmissions of only one band, the base station device simultaneously allocates radio resources of two bands to the terminal device, but the terminal device can only use one band.

[0023] In this way, the base station device cannot perform appropriate scheduling according to the number of simultaneous transmissions possible from the terminal device, which may result in a decrease in the efficiency of use of wireless communication resources between the terminal device and the base station device.

[0024] Therefore, a terminal device in one embodiment of the present invention is a terminal device in a mobile communication system that supports carrier aggregation, and receives an inquiry regarding terminal capability information of the terminal device from a base station device. In response to the received inquiry, the terminal device notifies the base station device of a simultaneous transmission number regarding the number of bands that can be transmitted simultaneously in carrier aggregation as terminal capability information. The terminal device dynamically changes bands based on the radio resources allocated by the base station device and transmits radio signals.

[0025] In this way, the base station device can perform appropriate scheduling according to the number of terminal devices that can transmit simultaneously. The terminal devices can transmit radio signals based on radio resources appropriately allocated by the base station device. Therefore, it is possible to improve the utilization efficiency of radio communication resources between the terminal devices and the base station device.

[0026] Returning to FIG. 1, the mobile communication system 100 is, for example, a mobile communication system that targets NR. Note that the present invention is applicable to any mobile communication system that includes at least a terminal device and a base station device, and is not limited to those that target NR. For example, the present invention is also applicable to LTE and LTE-Advanced. Furthermore, the present invention is also applicable to a mobile communication system that uses NR as part of the mobile communication system.

[0027] Hereinafter, LTE and LTE-Advanced are also referred to as E-UTRA (Evolved Universal Terrestrial Radio Access), but the meaning is the same. An area (coverage area) formed by a base station device is called a cell, and E-UTRA and NR are cellular communication systems constructed by multiple cells. The mobile communication system according to this embodiment may apply either TDD (Time Division Duplex) or FDD (Frequency Division Duplex), or different methods may be applied to each cell.

[0028] Terminal device 10-1 to terminal device 10-m are each wirelessly connected to one of base station device 50-1 to base station device 50-n. Furthermore, each of terminal device 10-1 to terminal device 10-m may be wirelessly connected to two or more of base station device 50-1 to base station device 50-n simultaneously. Base station device 50-1 to base station device 50-n can each use E-UTRA or NR. For example, base station device 50-1 may use NR and base station device 50-n may use E-UTRA, or vice versa. A base station device in E-UTRA is called an eNB (evolved NodeB), and a base station device in NR is called a gNB (g-NodeB).

[0029] Hereinafter, when a base station device is mentioned, it means both eNB and gNB. Furthermore, a terminal device in E-UTRA and NR is called UE (User Equipment). A base station device gNB in ​​NR may connect to a terminal device using a part of the frequency band it uses (BWP: Carrier Bandwidth Part). Hereinafter, when a cell is mentioned, it includes BWP.

[0030] Examples of the communication terminal 10 include portable information and communication devices such as IoT devices, smartphones, mobile phones, personal digital assistants (PDAs), tablet devices, portable game consoles, portable music players, and wearable devices. The terminal device 10 may be connected to a base station device 50 on a cell-by-cell basis, and may be connected using multiple cells, for example, through carrier aggregation. When the terminal device 10 is connected via multiple base station devices, i.e., in the case of dual connectivity, the base station device to which the terminal device 10 is initially connected is called a master node (MN), and the base station device to which the terminal device 10 is additionally connected is called a secondary node (SN). The base station devices are connected to each other via a base station interface. The base station device 50 and the core network device 90 are connected to each other via a core interface. The base station interface is used to exchange control signals necessary for handover and cooperative operations between the base station devices.

[0031] The core network device 90, for example, has the base station device 50 under its control, and mainly handles load control between the base station devices, calling (paging) the terminal device 10, location registration, and other mobility control. NR defines an Access and Mobility Management Function (AMF) that manages mobility and a Session Management Function (SMF) that manages sessions as a group of control plane (C-plane) functions in the core network device 90. E-UTRA defines an MME (Mobility Management Entity) that corresponds to the AMF.

[0032] 1 shows an example in which the core network device 90 is configured as a single device, but the present invention is not limited to this. For example, the core network device may be configured as multiple devices, including a server, a gateway, etc.

[0033] The terminal device 10 and the base station device 50 transmit and receive RRC messages in the Radio Resource Control (RRC) layer, and proceed with session processing (also referred to as a connection sequence). As the session processing proceeds, the terminal device 10 changes from an idle state (RRC Idle) to a connected state (RRC Connected) to the base station device 50. The idle state corresponds to a standby state of the terminal device 10.

[0034] Furthermore, the terminal device 10 and the base station device 50 transmit and receive MAC Control Elements (MAC CEs) in the Medium Access Control (MAC) layer. RRC messages are transmitted as RRC Protocol Data Units (PDUs). As logical channels to be mapped, a Common Control Channel (CCCH), a Dedicated Control Channel (DCCH), a Paging Control Channel (PCCH), a Broadcast Control Channel (BCCH), or a Multicast Control Channel (MCCH) is used. MAC CEs are transmitted as MAC PDUs (or MAC subPDUs). A MAC subPDU is equivalent to a Service Data Unit (SDU) in the MAC layer plus, for example, an 8-bit header, and a MAC PDU includes one or more MAC subPDUs.

[0035] Physical channels and physical signals related to an embodiment of the present invention will be described below. Among the physical channels related to the embodiment of the present invention, a Physical Broadcast Channel (PBCH), a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), a Physical Random Access Channel (PRACH), and a Physical Downlink Control Channel (PDCCH) will be described below.

[0036] In addition, in the mobile communication system according to the embodiment, there are at least a physical uplink control channel (PUCCH: Physical Uplink Control Channel), a physical downlink shared channel (PDSCH: Physical Downlink Shared Channel), a physical uplink shared channel (PUSCH: Physical Uplink Shared Channel), a scheduling reference signal (SRS: Scheduling Reference Signal), and a demodulation reference signal (DMRS: Demodulation Reference Signal), but detailed description thereof will be omitted.

[0037] <Physical Broadcast Channel (PBCH)> The physical broadcast channel (PBCH) is transmitted from the base station device 50 to the terminal device 10 and is used to notify common parameters (system information) in the cell under the control of the base station device 50. The system information is further classified into a master information block (MIB) and a system information block (SIB). The system information block is further subdivided into SIB1, SIB2, ... and transmitted.

[0038] The system information includes information necessary for connecting to a cell, and for example, the MIB includes a system frame number, information indicating whether camping on to a cell is possible, etc. Also, the SIB1 includes parameters for calculating the quality of a cell (cell selection parameters), cell-common channel information (random access control information, PUCCH control information, PUSCH control information), scheduling information for other system information, etc.

[0039] The Physical Broadcast Channel (PBCH) is periodically transmitted as a synchronization signal block (SSB: Synchronization Signal Block (or SS / PBSH)) in combination with a synchronization signal consisting of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS). By receiving the synchronization signal block (SSB), the terminal device 10 can acquire cell identifier (cell ID) information and reception timing, as well as measure the quality of the signal of the cell.

[0040] System information notified by a physical broadcast channel (PBCH) or the like is also called "system broadcast information" or "broadcast information." Camping on a cell refers to a state in which the terminal device 10 completes cell selection and / or cell reselection and selects a cell for monitoring system broadcast information and paging information. The terminal device 10 establishes the above-mentioned RRC connection with the base station device 50 that forms the camped-on cell.

[0041] <Primary Synchronization Signal (PSS)> The Primary Synchronization Signal (PSS) is used by the terminal device 10 to synchronize with the reception symbol timing and frequency of the downlink signal of the base station device 50. The Primary Synchronization Signal (PSS) is the signal that the terminal device 10 attempts to detect first in a procedure for detecting the cell of the base station device 50 (hereinafter also referred to as a "cell search procedure"). The Primary Synchronization Signal (PSS) uses three different signals, "0" to "2", repeatedly based on the physical cell ID. Note that the physical cell ID is an identifier of a physical cell, and 504 different IDs are used in E-UTRA, while 1008 different IDs are used in NR.

[0042] <Secondary Synchronization Signal (SSS)> The secondary synchronization signal (SSS) is used by the terminal device 10 to detect the physical ID of the base station device 50. Specifically, the secondary synchronization signal (SSS) is a signal used by the terminal device 10 to detect a physical cell ID in a cell search procedure. The secondary synchronization signal (SSS) repeatedly uses 168 different signals from "0" to "167" in E-UTRA and 336 different signals from "0" to "335" in NR based on the physical cell ID.

[0043] <Physical Random Access Channel (PRACH)> The physical random access channel (PRACH) is used by the terminal device 10 to transmit a random access preamble to the base station device 50. The physical random access channel (PRACH) is generally used in a state where uplink synchronization is not established between the terminal device 10 and the base station device 50, and is used for transmission timing adjustment information (timing advance) and uplink radio resource requests. Information indicating the radio resources available for transmitting the random access preamble is transmitted to the terminal using broadcast information or an RRC message.

[0044] <Physical Downlink Control Channel (PDCCH)> The Physical Downlink Control Channel (PDCCH) is transmitted from the base station device 50 to the terminal device 10 to notify the terminal device 10 of downlink control information (DCI). The downlink control information includes uplink radio resource information (uplink grant (UL grant)) that the terminal device 10 can use, or downlink radio resource information (downlink grant (DL grant)). The downlink grant is information indicating the scheduling of the Physical Downlink Shared Data Channel (PDSCH). The uplink grant is information indicating the scheduling of the Physical Uplink Shared Channel (PUSCH). When the Physical Downlink Control Channel (PDCCH) is transmitted in response to a random access preamble, the Physical Downlink Shared Data Channel (PDSCH) indicated by the Physical Downlink Control Channel (PDCCH) is a random access response, and includes index information of the random access preamble, transmission timing adjustment information, an uplink grant, etc.

[0045] <Hardware configuration> The hardware configuration of a terminal device and a base station device in one embodiment will be described with reference to Fig. 2. Fig. 2 is a configuration diagram showing an example of the hardware configuration of the terminal device 10 and the base station device 50.

[0046] As shown in FIG. 2, the terminal device 10 and the base station device 50 each include, for example, a processor 21, a memory 22, a storage device 23, a communication device 24, an input device 25, an output device 26, an antenna 27, and a sensor 29.

[0047] The processor 21 is configured to control the operation of each part of the terminal device 10 or the base station device 50. The processor 21 is configured to include integrated circuits such as a CPU (Central Processing Unit), a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), an FPGA (Field Programmable Gate Array), and an SoC (System-on-a-chip).

[0048] The memory 22 and the storage device 23 are configured to store programs, data, etc. The memory 22 is configured, for example, by a read-only memory (ROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), and / or a random access memory (RAM), etc. The storage device 23 is configured, for example, by a storage such as a hard disk drive (HDD), a solid state drive (SSD), and / or an embedded multi media card (eMMC).

[0049] The communication device 24 is configured to communicate via a wired and / or wireless network. The communication device 24 includes, for example, a network card, a communication module, etc. The communication device 24 also includes, for example, an amplifier, an RF (Radio Frequency) front end 243 that performs processing related to wireless signals, and a signal processing unit 241 that performs baseband signal processing.

[0050] The RF front end 243 generates a radio signal to be transmitted from the antenna 27 by, for example, performing D / A (Digital to Analog) conversion, modulation, frequency conversion, power amplification, etc. on the digital baseband signal received from the signal processing unit 241. The RF front end 243 also performs frequency conversion, demodulation, A / D (Analog to Digital) conversion, etc. on the radio signal received from the antenna 27 to generate a digital baseband signal and transmits it to the signal processing unit 241. The signal processing unit 241 performs a process of converting the digital baseband signal into an IP packet, and a process of converting the IP packet into the digital baseband signal.

[0051] The input device 25 is configured to allow a user to input information through operations. The input device 25 includes, for example, a keyboard, a touch panel, a mouse, and / or a microphone.

[0052] The output device 26 is configured to output information and includes a display device such as a liquid crystal display, an EL (Electro Luminescence) display, or a plasma display, and / or a speaker.

[0053] Antenna 27 is configured to emit and receive radio waves (electromagnetic waves) in one or more predetermined frequency bands. Antenna 27 may be a directional antenna. The gain of directional antenna 27 varies depending on the direction of the antenna. Antenna 27 may also be non-directional. The non-directional antenna 27 has approximately the same gain from all directions over 360 degrees in the horizontal plane, the vertical plane, or both the horizontal and vertical planes.

[0054] The antenna 27 is not limited to one. The terminal device 10 and the base station device 50 may each have multiple antennas. When the terminal device 10 and the base station device 50 have multiple antennas, they may be divided into transmitting antennas and receiving antennas, for example. When multiple antennas are divided into transmitting antennas and receiving antennas, at least one of them may include multiple antennas. When the terminal device 10 and the base station device 50 have multiple transmitting and receiving antennas or transmitting antennas, the beamforming technology described below can be used.

[0055] The sensors 29 included in the terminal device 10 include sensors that detect the position, orientation, and acceleration of the terminal device 10. The sensors 29 included in the terminal device 10 include, for example, at least one of a GPS (Global Positioning System) sensor, a gyro sensor, and an acceleration sensor. On the other hand, the sensors 29 included in the base station device 50 may include, for example, sensors that detect environmental information such as temperature, humidity, weather, or seismic intensity in the base station device 50.

[0056] <Function block configuration> (Terminal Device) The functional block configuration of a terminal device in one embodiment will be described with reference to Fig. 3. Fig. 3 is a configuration diagram showing an example of the functional block configuration of the terminal device 10. Note that Fig. 3 is intended to show the functional blocks necessary for explaining this embodiment, and does not exclude the terminal device 10 from including functional blocks other than those shown.

[0057] The terminal device 10 includes, as functional blocks, a receiving unit 11, a notifying unit 13, and a transmitting unit 15, for example.

[0058] The receiving unit 11 receives various information from the base station device 50 shown in Fig. 1. The receiving unit 11 receives, for example, an inquiry about terminal capability information (capability information) of the terminal device 10 from the base station device 50. As shown in Fig. 5 described later, the terminal capability information includes, for example, "UECapabilityInformation", and the inquiry about the terminal capability information (capability information) includes "UECapabilityEnquiry".

[0059] The notification unit 13 notifies the base station device 50 of various information in response to an inquiry from the base station device 50. For example, in response to a "UECapabilityEnquiry" received from the base station device 50, the notification unit 15 notifies the base station device 50 of the number of simultaneously transmittable bands in carrier aggregation as "UECapabilityInformation."

[0060] The notification unit 13 omits at least a part of the information included in the "UECapabilityInformation" notified in response to the "UECapabilityEnquiry" received from the base station device 50.

[0061] The transmitter 15 transmits a radio signal to the base station device 50. For example, the transmitter 15 dynamically changes bands that can be simultaneously transmitted in carrier aggregation based on radio resources allocated by the base station device 50, and transmits the radio signal. The transmitter 15 executes access control processing (for example, CA processing and MIMO processing) for transmitting a radio signal from the terminal device 10 to the base station device 50.

[0062] The receiving unit 11, the notifying unit 13, and the transmitting unit 15 may be realized by, for example, the communication device 24, or may be realized by the communication device 24 and the processor 21 executing a program stored in the storage device 23. When the processor 21 executes a program, the program may be stored in a storage medium. The storage medium storing the program may be a non-transitory computer-readable medium. The non-transitory storage medium is not particularly limited, and may be, for example, a storage medium such as a USB (Universal Serial Bus) memory or a CD-ROM (Compact Disc ROM).

[0063] (Base station equipment) The functional block configuration of a base station device in one embodiment will be described with reference to Fig. 4. Fig. 4 is a configuration diagram showing an example of the functional block configuration of a base station device 50. Note that Fig. 4 is intended to show functional blocks necessary for explaining this embodiment, and does not exclude the base station device 50 from including functional blocks other than those shown.

[0064] The base station device 50 includes, as functional blocks, an inquiry unit 51, a setting unit 53, an allocation unit 55, and a transmission unit 57, for example.

[0065] The inquiry unit 51 transmits a "UECapabilityEnquiry" to inquire about the terminal capability information "UECapabilityInformation" of the terminal device 10. The inquiry unit 51 receives the terminal capability information returned from the terminal device 10.

[0066] The setting unit 53 sets the MIMO layer of each CC during CA based on the terminal capability information of the terminal device 10 received by the inquiry unit 51.

[0067] The allocation unit 55 allocates radio resources for uplink CA processing to the terminal device 10 based on the terminal capability information of the terminal device 10 received by the inquiry unit 51.

[0068] The transmission unit 57 transmits information related to the MIMO layer of each CC during CA set by the setting unit 53 to the terminal device 10 as "RRCReconfiguration." Furthermore, the transmission unit 57 executes access processing (e.g., CA processing and MIMO processing) for transmitting a radio signal from the base station device 50 to the terminal device 10. The transmission unit 57 controls the access processing based on, for example, the information related to the MIMO layer of each CC during CA set by the setting unit 53.

[0069] The query unit 51, the setting unit 53, the allocation unit 55, and the transmission unit 57 may be realized by, for example, the communication device 24, or may be realized by the communication device 24 and the processor 21 executing a program stored in the storage device 23. When the processor 21 executes a program, the program may be stored in a storage medium. The storage medium storing the program may be a computer-readable non-transitory storage medium. The non-transitory storage medium is not particularly limited, and may be, for example, a storage medium such as a USB memory or a CD-ROM.

[0070] <Wireless signal transmission processing> An example of a wireless signal transmission process (including a first example of a transmission process of terminal capability information) of a terminal device according to an embodiment will be described with reference to Fig. 5 and Fig. 6. Fig. 5 is a flowchart showing an example of a wireless signal transmission process of a terminal device according to an embodiment. Fig. 6 is a conceptual diagram showing a first example of a transmission process of terminal capability information.

[0071] 5, the base station device 50 transmits a "UECapabilityEnquiry" to the terminal device 10 to inquire about the terminal capability information "UECapabilityInformation" of the terminal device 10 (step S1).

[0072] In response to an inquiry ("UECapabilityEnquiry") from the base station device 50, the terminal device 10 returns (notifies) its own terminal capability information "UECapabilityInformation" to the base station device 50 (step S3). As will be described later, the terminal capability information transmission process executed by the terminal device 10 includes various forms. First, a first example of the terminal capability information transmission process will be described below with reference to FIG. 6.

[0073] (Example 1) As shown in FIG. 6, in response to an inquiry received from the base station device 50, the terminal device 10 notifies the base station device of the number of bands that can be simultaneously transmitted in CA (the upper limit of the number of bands that can be simultaneously transmitted) as terminal capability information.

[0074] 6, the terminal device 10 includes a signal processing unit 241 corresponding to each of frequencies A, B, C, and D, an RF front end 243, and an antenna 27. Here, the number of bands that can be simultaneously transmitted in CA may vary depending on the combination of bands.

[0075] For example, when two bands are combined, a low band (e.g., 500 MHz to 900 MHz) and a mid band (e.g., 1 GHz or higher), simultaneous transmission is possible between the two bands, and the number of simultaneous transmissions possible is 2. On the other hand, when two low bands are combined, simultaneous transmission between the two bands is not possible, and the number of simultaneous transmissions possible is 1.

[0076] In the example of FIG. 6, frequencies A and B are in the low band, and frequencies C and D are in the mid band or high band. Even when all of frequencies A, B, C, and D are used for simultaneous transmission (A+B+C+D), the number of possible simultaneous transmissions (N max) is a total of three: one at frequency A and frequency B in the low band, one at frequency C in the mid band or high band, and one at frequency D in the mid band or high band.

[0077] Therefore, in the example of FIG. 6, the terminal device 10, in response to the inquiry received from the base station device 50, determines the number of simultaneous transmissions possible in CA (N shown in FIG. 6). max =3) is notified to the base station device as the terminal capability information.

[0078] 5, the base station device 50 sets the MIMO layer of each CC during CA based on the terminal capability information of the terminal device 10 received from the terminal device 10 (step S5). The base station device 50 transmits information regarding the set MIMO layer of each CC during CA to the terminal device 10 as "RRCReconfiguration."

[0079] The base station device 50 allocates radio resources for uplink CA based on the terminal capability information of the terminal device 10 received from the terminal device 10 (step S7).

[0080] The terminal device 10 dynamically changes the bands that can be simultaneously transmitted in CA based on the radio resources allocated by the base station device 50, and transmits radio signals (step S9). For example, the terminal device 10 executes access control processing (for example, CA processing and MIMO processing) for transmitting radio signals to the base station device 50.

[0081] As described above, the terminal device 10 according to one embodiment of the present invention is a terminal device 10 in a mobile communication system 100 compatible with carrier aggregation shown in FIG. 1, and receives an inquiry about terminal capability information of the terminal device 10 from a base station device 50. In response to the received inquiry, the terminal device 10 receives a simultaneous transmission number (for example, N shown in FIG. 6) about the number of bands that can be simultaneously transmitted in carrier aggregation. max=3) as terminal capability information to the base station device 50. The terminal device 10 dynamically changes the band based on the radio resources allocated by the base station device 50 and transmits data.

[0082] In this way, the base station device 50 determines the number of simultaneous transmissions possible (for example, N max =3) can be acquired in advance, making it possible to perform appropriate scheduling according to the number of simultaneous transmissions possible for the terminal device 10. The terminal device 10 can transmit data based on the radio resources appropriately allocated by the base station device 50. Therefore, it is possible to improve the utilization efficiency of radio communication resources between the terminal device 10 and the base station device 50.

[0083] (Example 2) In a second example of the terminal capability information transmission process, the terminal device 10 notifies the base station device of the combination of bands that can be transmitted simultaneously and that meet a predetermined condition, in addition to the number of simultaneous transmissions possible, and the number of simultaneous transmissions possible for each combination of bands, as terminal capability information. Below, differences from the first example will be particularly described.

[0084] A second example of the terminal capability information notification process executed by the notification unit 13 of the terminal device 10 shown in Fig. 3 will be described with reference to Fig. 7. Fig. 7 is a conceptual diagram showing the second example of the terminal capability information notification process.

[0085] When the terminal device 10 satisfies a "predetermined condition" related to a combination of bands that can be simultaneously transmitted in carrier aggregation (CA), the terminal device 10 further notifies the base station device 50 of information related to the combination of bands that satisfies the "predetermined condition" and the number of simultaneous transmissions that can be made for each combination. The "predetermined condition" includes the existence of a combination of bands that results in a number that is smaller than the sum of the number of simultaneous transmissions that can be made for each of the multiple bands.

[0086] For example, the number of simultaneous transmissions possible for each of the four frequencies A, B, C, and D is generally 1. However, in the case of a combination of two bands, a low band and a low band, as in the example of Fig. 6, simultaneous transmission is not possible on both bands, so there is a restriction imposed by the band combination, such that the number of simultaneous transmissions possible is 1. Therefore, in the example of Fig. 7, as in the example of Fig. 6, there is a band combination in which the number is smaller than the sum of the number of simultaneous transmissions possible for each of the multiple bands.

[0087] That is, in the example of Figure 7, the band combinations that satisfy the specified conditions refer to, for example, three combinations (A+B+C), (A+B+D), and (A+B) that include at least the combination (A+B) of frequency A and frequency B, which are low bands, as band combinations for simultaneous transmission.

[0088] According to the second example of the terminal capability information transmission process, as shown in FIG. 7, the terminal device 10 max =3), and also the combination of bands that can be transmitted simultaneously ((A+B+C), (A+B+D), (A+B)) that meets the specified conditions, and the number of simultaneous transmissions possible for each combination of bands (N BC,max =2,N BC,max =2,N BC,max =1) is notified to the base station device as the terminal capability information.

[0089] In this way, the base station device 50 determines the number of simultaneous transmissions possible (for example, N max =3), and also the combination of bands that can be transmitted simultaneously ((A+B+C), (A+B+D), (A+B)) that meets the specified conditions, and the number of simultaneous transmissions possible for each combination of bands (N BC,max =2,N BC,max =2,N BC,max =1) can be acquired in advance. Therefore, the base station device 50 can refer to the combination of bands that can be transmitted simultaneously and that meets a predetermined condition, and the number of bands that can be transmitted simultaneously for each combination of bands, and can therefore perform more appropriate scheduling according to the terminal capability information of the terminal device 10.

[0090] (Modification of the second example) In a modified example of the second example of the terminal capability information transmission process, the terminal device 10 includes a signal processing unit 241 corresponding to frequency C, RF front ends 243A and 243B, and antennas 27A and 27B. The modified example of the second example differs from the second example in that the terminal device 10 includes one signal processing unit 241, one RF front end 243, and one antenna 27 corresponding to each of frequencies A, B, C, and D. The following will particularly describe the differences from the second example.

[0091] A modified example of the second example of the terminal capability information notification process executed by the notification unit 13 of the terminal device 10 shown in Fig. 3 will be described with reference to Fig. 8. Fig. 8 is a conceptual diagram showing a modified example of the second example of the terminal capability information notification process.

[0092] In the example of Figure 8, in the case of a combination of two bands, frequency A and frequency B, which are low bands, as in the example of Figure 7, simultaneous transmission is not possible on both bands, so the number of simultaneous transmissions possible for the band combination (A+B) is one.

[0093] Furthermore, in the case of a band combination (B+C) of adjacent frequencies B and C, as described in Fig. 12, the terminal device 10 dynamically switches between a case where two bands in frequency C are used simultaneously and a case where one band in frequency B and one band in frequency C are used simultaneously. That is, the number of simultaneous transmissions possible for the band combination (B+C) of frequencies B and C is 2. Therefore, in the example of Fig. 8 as well, as in the example of Fig. 7, there exists a band combination where the number is smaller than the sum of the number of simultaneous transmissions possible for each of the multiple bands.

[0094] In the example of Figure 8, a band combination that satisfies a specified condition refers to, for example, three combinations (A+B+C), (A+B), and (B+C) including a combination of frequency A and frequency B (A+B) or a combination of frequency B and frequency C (B+C) as band combinations for simultaneous transmission.

[0095] According to a modified example of the second example of the terminal capability information transmission process, as shown in FIG. 8, the terminal device 10 determines the number of simultaneous transmissions possible (N max =3), and also the combination of bands that can be transmitted simultaneously ((A+B+C), (A+B), (B+C)) that meets the specified conditions, and the number of simultaneous transmissions possible for each combination of bands (N BC,max =3,N BC,max =1,N BC,max =2) is notified to the base station device as terminal capability information. As described above, the number of simultaneous transmissions possible for the combination of bands (A+B+C) that satisfies the predetermined conditions is three, but this is because when frequency A and frequency C are used among the above band combinations, the (maximum) number of transmissions possible is three.

[0096] In this way, the base station device 50 determines the number of simultaneous transmissions possible (for example, N max =3), and also the combination of bands that can be transmitted simultaneously ((A+B+C), (A+B), (B+C)) that meets the specified conditions, and the number of simultaneous transmissions possible for each combination of bands (N BC,max =3,N BC,max =1,N BC,max =2) can be acquired in advance. Therefore, the base station device 50 can refer to the combination of bands that can be transmitted simultaneously and that meets a predetermined condition, and the number of simultaneous transmissions that can be made for each combination of bands, and can therefore perform more appropriate scheduling according to the terminal capability information of the terminal device 10.

[0097] (Example 3) The third example of the terminal capability information transmission process differs from the second example in that the second example omits transmission of part of the terminal capability information that the terminal device 10 notifies to the base station device 50. The following will particularly describe the differences from the second example.

[0098] A third example of the terminal capability information notification process executed by the notification unit 13 of the terminal device 10 shown in Fig. 3 will be described with reference to Fig. 9. Fig. 9 is a conceptual diagram showing the third example of the terminal capability information notification process.

[0099] As shown in FIG. 9, the terminal device 10 collects information on (1) the band combinations ((A+B+C), (A+B+D), (A+B)) that satisfy the predetermined conditions shown in FIG. 8 , other than the band combination (A+B) that has the smallest number of bands that can be simultaneously transmitted in CA ((A+B+C), (A+B+D)), and (2) the number of simultaneously transmitted bands (N BC,max =2,N BC,max =2) The notification to at least one of the base station devices 50 is omitted.

[0100] According to the third example of the terminal capability information transmission process, compared to the second example, the terminal device 10 can significantly reduce the amount of terminal capability information to be transmitted to the base station device 50. Therefore, compared to the second example, it is possible to further improve the utilization efficiency of wireless communication resources between the terminal device 10 and the base station device 50.

[0101] As described above, the information of the terminal capability information that is omitted from notification may be only the information (1) above or only the information (2) above. However, omitting notification of both the information (1) and the information (2) above can reduce the amount of information to be notified from the terminal device 10 to the base station device 50 more than when omitting notification of one of the pieces of information. Therefore, the utilization efficiency of wireless communication resources between the terminal device 10 and the base station device 50 can be further improved.

[0102] (Example 4) In a fourth example of the terminal capability information transmission process, the terminal device 10 notifies the base station device of the combination of bands that can be transmitted simultaneously and the number of simultaneous transmissions possible for each combination of bands as terminal capability information. Below, differences from the first to third examples will be particularly described.

[0103] A fourth example of the terminal capability information notification process executed by the notification unit 13 of the terminal device 10 shown in Fig. 3 will be described with reference to Fig. 10. Fig. 10 is a conceptual diagram showing the fourth example of the terminal capability information notification process.

[0104] According to the fourth example of the terminal capability information transmission process, the terminal device 10 is a terminal device 10 in a mobile communication system 100 that supports CA, and receives an inquiry about the terminal capability information of the terminal device 10 from the base station device 50. As shown in FIG. 10, in response to the received inquiry, the terminal device 10 transmits information about combinations of bands that can be simultaneously transmitted in CA ((A+B+C+D), (A+B+C), (A+B+D), ..., (C+D), (A), (B), (C), (D)), and the number of simultaneously transmittable bands for each combination (N BC,max =3,N BC,max =2,N BC,max =2,N BC,max =3,…,N BC,max =2,N BC,max =1,N BC,max =1N BC,max =1,N BC,max =1) to the base station device 50. The terminal device 10 dynamically changes the band based on the radio resources allocated by the base station device 50 and transmits data.

[0105] In this way, the base station device 50 can acquire in advance, as terminal capability information, information regarding combinations of bands that can be simultaneously transmitted in CA and the number of simultaneously transmittable bands for each combination, and can therefore perform appropriate scheduling according to the terminal capability information of the terminal device 10. The terminal device 10 can transmit data based on radio resources that are appropriately allocated by the base station device 50. Therefore, it is possible to improve the utilization efficiency of radio communication resources between the terminal device 10 and the base station device 50.

[0106] (Example 5) The fifth example of the terminal capability information transmission process differs from the fourth example in that transmission of part of the terminal capability information that the terminal device 10 notifies the base station device 50 of in the fourth example is omitted.

[0107] A fifth example of the terminal capability information notification process executed by the notification unit 13 of the terminal device 10 shown in Fig. 3 will be described with reference to Fig. 11. Fig. 11 is a conceptual diagram showing the fifth example of the terminal capability information notification process.

[0108] As shown in FIG. 11 , the terminal device 10 collects information on (3) band combinations ((A+B+C+D), (A+B+C), (A+B+D), ..., (C+D), (A), (B), (C), (D)) other than the band combinations ((A+B+C+D), (A+B+C), (A+B+D), (A+B)) that satisfy the above-mentioned predetermined condition regarding band combinations that can be simultaneously transmitted in CA (including, for example, the existence of a band combination that results in a number that is smaller than the sum of the numbers of simultaneous transmissions possible for each of a plurality of bands), among the band combinations that can be simultaneously transmitted in CA ((A+B+C+D), (A+B+C), (A+B+D), ..., (C+D), (A), (B), (C), (D)), and (4) the number of simultaneous transmissions possible (N BC,max =3,N BC,max =2,N BC,max =2,…,N BC,max =1,N BC,max =1,N BC,max =1,N BC,max =1), the notification to at least one of the base station devices 50 is omitted.

[0109] According to the fifth example of the terminal capability information transmission process, compared to the fourth example, the terminal device 10 can significantly reduce the amount of terminal capability information to be transmitted to the base station device 50. Therefore, compared to the fourth example, it is possible to further improve the utilization efficiency of wireless communication resources between the terminal device 10 and the base station device 50.

[0110] As described above, the information of the terminal capability information that is omitted from notification may be only the information (3) above or only the information (4) above. However, omitting notification of both the information (3) and the information (4) above can reduce the amount of information to be notified from the terminal device 10 to the base station device 50 more than when omitting notification of one of the pieces of information. Therefore, the utilization efficiency of wireless communication resources between the terminal device 10 and the base station device 50 can be further improved.

[0111] The above-described embodiments and examples are intended to facilitate understanding of the present invention and are not to be construed as limiting the present invention. The present invention may be modified or improved without departing from the spirit thereof, and equivalents thereof are also included in the present invention. Furthermore, the present invention can be formed into various disclosures by appropriately combining multiple components disclosed in the above-described embodiments or examples. For example, some components may be deleted from all the components shown in the embodiments. Furthermore, components may be appropriately combined in different embodiments. [Explanation of symbols]

[0112] 10 (10-1...10-m)...terminal device, 11...receiving unit, 13...notifying unit, 15, 57...transmitting unit, 21...processor, 22...memory, 23...storage device, 24...communication device, 25...input device, 26...output device, 27A, 27B...antenna, 29...sensor, 50 (50-1...50-n)...base station device, 51...inquiry unit, 53...setting unit, 55...allocation unit, 90...core network device, 100...mobile communication system, signal processing unit 241, 243A, 243B...RF front end

Claims

1. A terminal device in a mobile communication system that supports carrier aggregation, a receiving unit that receives an inquiry about capability information of a terminal device from a base station device; a notification unit that notifies the base station device of a number of bands that can be simultaneously transmitted in the carrier aggregation as the capability information in response to the inquiry; a transmitter that dynamically changes the band based on radio resources allocated by the base station device and transmits a radio signal; Equipped with When a predetermined condition regarding a combination of bands that can be simultaneously transmitted in the carrier aggregation is satisfied, the notification unit further notifies the base station device of information regarding a combination of bands that satisfies the predetermined condition and the number of simultaneous transmissions possible for each combination, and omits notification to the base station device of at least one of information regarding a combination of bands other than the combination of bands that has the fewest number of bands that can be simultaneously transmitted in the carrier aggregation, among the combinations of bands that satisfy the predetermined condition, and the number of simultaneous transmissions possible for each combination of bands other than the combination of bands that has the fewest number of bands. Terminal device.

2. A terminal device in a mobile communication system that supports carrier aggregation, a receiving unit that receives an inquiry about capability information of a terminal device from a base station device; a notification unit that notifies the base station device of a number of bands that can be simultaneously transmitted in the carrier aggregation as the capability information in response to the inquiry; a transmitter that dynamically changes the band based on radio resources allocated by the base station device and transmits a radio signal; Equipped with When a predetermined condition regarding a combination of bands that can be transmitted simultaneously in the carrier aggregation is satisfied, the notification unit further notifies the base station device of information regarding the combination of bands that satisfies the predetermined condition and the number of bands that can be transmitted simultaneously for each combination; the predetermined condition includes a condition that a combination of bands exists in which the number of simultaneous transmissions is smaller than the sum of the number of simultaneous transmissions for each of the plurality of bands. Terminal device.

3. A wireless communication method used by a terminal device in a mobile communication system that supports carrier aggregation, receiving an inquiry regarding capability information of a terminal device from a base station device; In response to the inquiry, notifying the base station device of a number of bands that can be simultaneously transmitted in the carrier aggregation as the capability information; dynamically changing the band based on radio resources allocated by the base station device and transmitting a radio signal; Including, In the notifying step, when a predetermined condition regarding a combination of bands that can be simultaneously transmitted in the carrier aggregation is satisfied, information regarding a combination of bands that satisfies the predetermined condition and the number of simultaneous transmissions possible for each combination are further notified to the base station device, and notification to the base station device of at least one of information regarding a combination of bands other than the combination of bands that has the fewest number of bands that can be simultaneously transmitted in the carrier aggregation among the combinations of bands that satisfy the predetermined condition and the number of simultaneous transmissions possible for each combination of bands other than the combination of bands that has the fewest number of bands is omitted. Wireless communication method.

4. A wireless communication method used by a terminal device in a mobile communication system that supports carrier aggregation, receiving an inquiry regarding capability information of a terminal device from a base station device; In response to the inquiry, notifying the base station device of a number of bands that can be simultaneously transmitted in the carrier aggregation as the capability information; dynamically changing the band based on radio resources allocated by the base station device and transmitting a radio signal; Including, In the notifying step, when a predetermined condition regarding a combination of bands that can be simultaneously transmitted in the carrier aggregation is satisfied, information regarding the combination of bands that satisfies the predetermined condition and the number of bands that can be simultaneously transmitted for each combination are further notified to the base station device; the predetermined condition includes a condition that a combination of bands exists in which the number of simultaneous transmissions is smaller than the sum of the number of simultaneous transmissions for each of the plurality of bands. Wireless communication method.

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