Terminal device and wireless communication method

Abstract

Provided is a terminal device (10) that is capable of wirelessly communicating with a plurality of base station devices (50), the terminal device (10) comprising: a reception unit (11) that receives an inquiry from one base station device among the plurality of base station devices (50); and a notification unit (15) that, when the terminal device (10) is capable of communicating with the plurality of base station devices (50) arranged at different positions, notifies the one base station device, on the basis of the inquiry, regarding interference information relating to interference between wireless signals when the terminal device (10) transmits a wireless signal to each of the plurality of base station devices (50) arranged at different positions. 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 devices (50).

Description

Terminal device and wireless communication method

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

[0002] The international standardization organization 3GPP (Third Generation Partnership Project) is 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), which realizes high-speed, large-capacity communication; ultra-reliable and low latency communication (URLLC), which realizes ultra-reliable and low latency communication; and massive Machine Type Communication (mMTC), which realizes 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). NR also employs E-UTRA-NR Dual Connectivity (EN-DC), which uses base station devices eNB (evolved NodeB) in E-UTRA (Evolved Universal Terrestrial Radio Access) and base station devices gNB (g-NodeB) in NR (see Non-Patent Document 2). Regarding EN-DC, two known scenarios are known: a collocated scenario in which eNBs and gNBs located in the same position communicate with a terminal device, and a non-collocated scenario in which eNBs and gNBs located in different positions communicate with a terminal device.

[0004] In NR, in Intra-band EN-DC and Intra-band NR CA, the terminal device supports a co-location scenario as a Type 1 UE. In Intra-band EN-DC, the terminal device supports a non-co-location scenario in which a 2x2 MIMO scheme (maximum number of usable MIMO layers is 2) can be used for each CC as a Type 2 UE (see Non-Patent Document 3). In this case, a terminal device (Type 2 UE) that supports the non-co-location scenario notifies the base station device of this by including it in the terminal device's terminal capability information "UECapabilityInformation" (see Non-Patent Document 1).

[0005] In a wireless communication system employing a non-co-location scenario, the distance between a terminal device and each of multiple base station devices located at different locations is different. The terminal device performs transmission power control for transmitting a radio signal to each of the base station devices located at different locations according to the distance. Therefore, the transmission power when the terminal device transmits a radio signal to one base station device is different from the transmission power when transmitting a radio signal to another base station device. For example, when the terminal device transmits a radio signal to base station device A located at a distance A from the terminal device that is longer than distance B, the radio signal is transmitted at a higher power than when the terminal device transmits a radio signal to base station device B located at a distance B from the terminal device. In this case, the high-power radio signal, i.e., the radio signal transmitted to base station device A located at distance A from the terminal device, leaks (emissions) to other frequencies, causing significant interference with the low-power radio signal, i.e., the radio signal transmitted to base station device B located at distance B from the terminal device.

[0006] Incidentally, Non-Patent Document 4 specifies the allowable emission level of a terminal device. Specifically, Non-Patent Document 4 describes that when a terminal device performs wireless communication using a frequency exceeding 1 GHz, emissions of up to −30 dBm / MHz are allowable.

[0007] 3GPP standards “TS 38.306 Ver.16.7.0 (2021-12)” 3GPP standards “TS 37.340 Ver.16.8.0 (2021-12)” 3GPP standards “TS 38.133 Ver.17.5.0 (2022-04)” 3GPP standards “TS 38.101-1 Ver.17.6.0 (2022-06)”

[0008] However, in conventional wireless communication systems, a base station device only has information about the allowable emission level of a terminal device. The base station device cannot know interference information about interference between radio signals when the base station device transmits radio signals to multiple base stations located in different locations, and the terminal devices that can actually communicate with the base station device are located in different locations. Therefore, conventional communication methods cannot perform appropriate scheduling based on interference information about the terminal devices. This may result in a decrease in the utilization efficiency of wireless communication resources between the terminal devices and the base station device.

[0009] 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.

[0010] A terminal device according to one aspect of the present invention is a terminal device capable of wireless communication with a plurality of base station devices, and includes: a receiving unit that receives an inquiry from one of the plurality of base station devices; and, if the terminal device is capable of communicating with a plurality of base station devices located at different locations, a notification unit that, based on the inquiry, notifies the one base station device of interference information regarding interference between radio signals when the terminal device transmits radio signals to each of the plurality of base station devices located at different locations.

[0011] A wireless communication method according to one aspect of the present invention is a wireless communication method executed by a terminal device capable of wireless communication with a plurality of base station devices, and includes receiving an inquiry from one of the plurality of base station devices, and, if the terminal device is capable of communicating with a plurality of base station devices located at different locations, notifying the one base station device of interference information regarding interference between wireless signals when the terminal device transmits wireless signals to each of the plurality of base station devices located at different locations based on the inquiry.

[0012] 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.

[0013] FIG. 1 is a configuration diagram showing an example of a schematic configuration of a wireless communication system in an embodiment. 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. FIG. 3 is a configuration diagram showing an example of a functional block configuration of a terminal device in an embodiment. FIG. 4 is a configuration diagram showing an example of a functional block configuration of a base station device in an embodiment. FIG. 5 is a flowchart showing an example of a wireless signal transmission process of a terminal device in an embodiment. FIG. 6 is a flowchart showing an example of a wireless signal transmission process of a terminal device in an embodiment. FIG. 7 is a flowchart showing an example of a wireless signal transmission process of a terminal device in an embodiment. FIG. 8 is a diagram showing an example of an interference situation between wireless signals when a terminal device transmits wireless signals to each of multiple base station devices located at different positions in an embodiment.

[0014] 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.

[0015] With reference to FIG. 1, a schematic configuration of a wireless communication system in an embodiment will be described. FIG. 1 is a configuration diagram showing an example of a schematic configuration of a wireless communication system 100. The wireless communication system 100 is configured to include terminal devices 10-1 to 10-m, base station devices 50-1 to 50-n, and a core network device 90. The wireless communication system 100 is, for example, a wireless communication system that targets NR (New Radio). Note that the present invention is applicable to any wireless 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. The present invention is also applicable to wireless communication systems that use NR as part of the wireless communication system.

[0016] Hereinafter, LTE and LTE-Advanced are also referred to as E-UTRA (Evolved Universal Terrestrial Radio Access). 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 wireless 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.

[0017] Each of the terminal devices 10-1 to 10-m is wirelessly connected to one of the base station devices 50-1 to 50-n. Furthermore, each of the terminal devices 10-1 to 10-m may be wirelessly connected to two or more of the base station devices 50-1 to 50-n simultaneously. Each of the base station devices 50-1 to 50-n can use E-UTRA or NR. For example, the base station device 50-1 may use NR and the 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).

[0018] The wireless communication system 100 is a wireless communication system that supports, for example, carrier aggregation (CA) and E-UTRA-NR Dual Connectivity (EN-DC). Carrier aggregation refers to a process that enables bandwidth expansion by aggregating (bundling) multiple frequency bands, for example, 20 MHz, called component carriers (CC).

[0019] In EN-DC (E-UTRA-NR Dual Connectivity), a base station device eNB and a base station device gNB can cooperate to communicate with a terminal device 10. For example, a scenario in which an eNB and a gNB located in the same position communicate with a terminal device 10 is called a collocated scenario, and a scenario in which an eNB and a gNB located in different positions communicate with a terminal device 10 is called a non-collocated scenario.

[0020] An overview of a wireless communication system 100 according to an embodiment of the present invention will now be described. Fig. 8 is a diagram showing an example of interference between wireless signals when a terminal device transmits wireless signals to multiple base station devices located at different locations according to the embodiment. For example, when a terminal device transmits a wireless signal at frequency F2 to base station device B located at distance B from the terminal device, transmission power output P1 is higher than transmission power output P2 when the terminal device transmits a wireless signal at frequency F1 to base station device A located at distance A from the terminal device, which is longer than distance B.

[0021] As described above, in conventional wireless communication systems, the base station device only has information about the allowable emission level of the terminal device. Therefore, if the actual emission level EL of the transmission power output P2 at frequency F2 is similar to the allowable emission level AL, or if it is equal to or lower than the allowable emission level AL but not significantly lower than the allowable emission level AL, the base station device determines that the transmission power output P2 is significantly affected by interference with the transmission power output P1 (i.e., the transmission power output P2 is defeated by the interference), and does not allow simultaneous uplink transmission from multiple carriers (multiple terminal devices).

[0022] On the other hand, when the actual emission level EL of the transmission power output P2 at frequency F2 is significantly lower than the allowable emission level AL, the base station device can allow simultaneous uplink transmission from multiple terminal devices because the transmission power output P2 is not significantly affected by interference with the transmission power output P1 (the transmission power output P2 is not affected by the interference). However, as described above, the base station device only has information about the allowable emission level AL of the terminal devices and is therefore unable to grasp the actual interference situation. Therefore, even if the base station device can actually allow simultaneous uplink transmission from multiple terminal devices, it may not be able to allow simultaneous uplink transmission from multiple terminal devices.

[0023] Therefore, a terminal device in an embodiment of the present invention is a terminal device capable of wireless communication with multiple base station devices, and is equipped with a receiving unit that receives an inquiry regarding capability information of the terminal device from one of the multiple base station devices, and a notification unit that, when the terminal device is capable of communicating with multiple base station devices located at different locations, notifies the one base station device of interference information regarding interference between radio signals when the terminal device transmits radio signals to each of the multiple base station devices located at different locations based on the inquiry.

[0024] In this way, the base station device can obtain, through an inquiry, interference information regarding interference between radio signals when a terminal device transmits radio signals to each of multiple base station devices located at different locations. Therefore, the base station device can perform appropriate scheduling based on the obtained interference information. This makes it possible to improve the utilization efficiency of wireless communication resources between the terminal device and the base station device. Furthermore, since appropriate scheduling is performed, it is possible to improve the throughput of uplink communication for the terminal device. Therefore, the technology according to this embodiment can contribute to achieving Goal 9 of the Sustainable Development Goals (SDGs), "Build resilient infrastructure, promote inclusive and sustainable industrialization, and promote innovation and resilience."

[0025] The following describes in detail each component of the wireless communication system 100. FIG. 1 illustrates terminal device 10-1 to terminal device 10-m as m terminal devices (m is an integer of 2 or more). In the following description, when describing these m terminal devices without distinguishing between them, some of the reference numerals are omitted and they are simply referred to as "terminal device 10." FIG. 1 also illustrates base station device 50-1 to base station device 50-n as n base station devices (n is an integer of 2 or more). In the following description, when describing these n base station devices without distinguishing between them, some of the reference numerals are omitted and they are simply referred to as "base station device 50." A terminal device in E-UTRA and NR is referred to as 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). In the following, when referring to a cell, it is assumed that the BWP is included.

[0026] 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, e.g., carrier aggregation. When the terminal device 10 is connected via multiple base station devices, i.e., in the case of DC (Dual Connectivity), the base station device initially connected is called a master node (MN), and additionally connected base station devices are called secondary nodes (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 via a core interface. The base station interface is used to exchange control signals necessary for handover and cooperative operations between base station devices.

[0027] The core network device 90, for example, has the base station device 50 under its control, and mainly handles load control between base station devices, calling (paging) of the terminal device 10, location registration, and other mobility control. In NR, the core network device 90 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 E-UTRA, an MME (Mobility Management Entity) corresponding to the AMF is defined.

[0028] 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.

[0029] 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.

[0030] 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). 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 as a logical channel to be mapped. A MAC CE is transmitted as a MAC PDU (or MAC subPDU). 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.

[0031] The following describes physical channels and physical signals related to an embodiment of the present invention. 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.

[0032] In addition, in the wireless communication system according to the embodiment, there are at least a physical uplink control channel (PUCCH), a physical downlink shared channel (PDSCH), a physical uplink shared channel (PUSCH), a scheduling reference signal (SRS), and a demodulation reference signal (DMRS), but detailed description thereof will be omitted.

[0033] <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.

[0034] 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 of other system information, etc.

[0035] 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.

[0036] 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.

[0037] <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 first attempts to detect in the procedure for detecting the cell of the base station device 50 (hereinafter also referred to as the "cell search procedure"). The primary synchronization signal (PSS) repeatedly uses three signals, "0" to "2", 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.

[0038] <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 that the terminal device 10 uses 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.

[0039] <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.

[0040] <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.

[0041] <Hardware Configuration> The hardware configuration of the terminal device and the 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.

[0042] 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.

[0043] 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 a SoC (System-on-a-chip).

[0044] 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 device such as a hard disk drive (HDD), a solid state drive (SSD), and / or an embedded multi media card (eMMC).

[0045] 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.

[0046] 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 a digital baseband signal.

[0047] The input device 25 is configured to allow a user to input information through operations, and includes, for example, a keyboard, a touch panel, a mouse, and / or a microphone.

[0048] 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.

[0049] The antenna 27 is configured to emit and receive radio waves (electromagnetic waves) in one or more predetermined frequency bands. The antenna 27 may be a directional antenna. The gain of the directional antenna 27 varies depending on the orientation of the antenna. The 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.

[0050] The antenna 27 is not limited to one. The terminal device 10 and the base station device 50 may be equipped with multiple antennas. As described above, the terminal device 10 and the base station device 50 each have multiple antennas so that the 2x2 MIMO system and the 4x4 MIMO system can be used. When the terminal device 10 and the base station device 50 have multiple antennas, for example, they may be divided into transmitting antennas and receiving antennas. Furthermore, when multiple antennas are divided into transmitting antennas and receiving antennas, at least one of them may include multiple antennas. Note that when the terminal device 10 and the base station device 50 have multiple transmitting / receiving antennas or transmitting antennas, the above-mentioned beamforming technology can be used.

[0051] 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.

[0052] <Functional Block Configuration> (Terminal Device) The functional block configuration of the terminal device in this 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.

[0053] The terminal device 10 includes, as functional blocks, a receiving unit 11, a comparing unit 13, a notifying unit 15, and a transmitting unit 17, for example.

[0054] The receiver 11 receives various types of information from the base station device 50 shown in Fig. 1. The receiver 11 receives, for example, an inquiry from the base station device 50 regarding terminal capability information of the terminal device 10. As shown in Figs. 5 to 7 described below, the terminal capability information includes, for example, "UECapabilityInformation," and the inquiry regarding the terminal capability information includes "UECapabilityQuery."

[0055] When the base station device 50 (the determining unit 53 shown in FIG. 4) determines that communication with the base station device 50 is possible (simultaneous uplink transmission is possible), the receiving unit 11 receives a response to that effect.

[0056] The receiver 11 may receive a radio signal transmitted by the base station device 50 using a MIMO scheme set based on, for example, terminal capability information related to the MIMO scheme. When a MIMO scheme suitable for the terminal capability of the terminal device 10 is set, the base station device 50 executes access control processing (for example, CA processing and MIMO processing) for transmitting a radio signal to the terminal device 10. The receiver 15 receives the radio signal transmitted after the access control processing has been executed by the base station device 50.

[0057] The comparator 13 compares an interference level indicating the degree of interference of the terminal device 10 (for example, EL shown in FIG. 8: actual emission level of the terminal device) with a predetermined threshold value (for example, "tolerance value" shown in FIG. 8). The actual "emission level" of the terminal device 10 is set to a certain value for each terminal device 10, but this does not exclude the possibility that the "emission level" may vary depending on the actual communication situation. The actual "emission level" of the terminal device 10 is set based on, for example, parts and materials (for example, amplifiers and filters) used in the manufacturing process of the terminal device.

[0058] The "predetermined threshold" is a tolerance value, for example, a tolerance emission level. The tolerance emission level is set according to the frequency used by the terminal device 10. For example, the tolerance emission level may be set to -30 dBm / MHz when the frequency used by the terminal device 10 is 1 GHz or higher. The "predetermined threshold" may be stored in advance by the terminal device 10, or may be transmitted to the terminal device 10 as a report signal from at least one base station device of the multiple base station devices 50.

[0059] The notification unit 15 notifies the base station device 50 of various information in response to an inquiry from the base station device 50. For example, the notification unit 13 responds (notifies) the base station device 50 of “UECapabilityInformation” based on “UECapabilityEnquiry” received from the base station device 50.

[0060] The notification unit 15 notifies the base station device 50 of the comparison result, obtained by the comparison unit 13 comparing the interference level indicating the degree of interference of the terminal device 10 with a predetermined threshold, as terminal capability information (interference information). The notification unit 15 may notify the base station device 50 of the comparison result as terminal capability information when the comparison result by the comparison unit 13 satisfies a predetermined condition. The "comparison result" may include, for example, information indicating that the interference level of the terminal device 10 is significantly smaller than the allowable value, as well as information regarding at least one of the difference and ratio between the interference level of the terminal device 10 and the allowable value.

[0061] The "predetermined condition" includes a condition regarding at least one of the difference and ratio between the interference level of the terminal device 10 and the allowable value. The "predetermined condition" includes, for example, the difference (absolute value) between the interference level of the terminal device 10 and the allowable value being greater than a set value (for example, the interference level of the terminal device 10 being significantly smaller than the allowable value).

[0062] The notification unit 15 may notify, as interference information, an interference level indicating the degree of interference of the terminal device 10. Furthermore, the notification unit 15 may notify, as interference information, information based on the interference level of the terminal device 10 and a tolerance (predetermined threshold) (e.g., −30 dBm / MHz). The information based on the interference level of the terminal device 10 and the tolerance includes, for example, information on at least one of the difference and ratio between the interference level of the terminal device 10 and the tolerance.

[0063] The notification unit 15 may notify the base station device 50 of the availability information in any form as long as it can notify the base station device 50. The notification unit 15 is not limited to notifying the interference information as "UECapabilityInformation", and may notify the availability information as other information.

[0064] The transmitter 17 transmits a radio signal to the base station device 50. The transmitter 17 executes simultaneous uplink transmission based on a response from the terminal device 50 that simultaneous uplink transmission is possible.

[0065] Furthermore, the transmitter 17 transmits radio signals by dynamically changing bands that can be simultaneously transmitted in carrier aggregation, for example, based on radio resources allocated by the base station device 50. The transmitter 17 executes access control processing (for example, CA processing and MIMO processing) for transmitting radio signals from the terminal device 10 to the base station device 50.

[0066] The receiving unit 11, the comparing unit 13, the notifying unit 15, and the transmitting unit 17 may be realized by, for example, the communication device 24 shown in FIG. 2 , 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).

[0067] (Base Station Device) The functional block configuration of a base station device in this 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.

[0068] The base station device 50 includes, as functional blocks, an inquiry unit 51, a determination unit 53, and a transmission unit 55, for example.

[0069] The inquiry unit 51 transmits a "UECapabilityQuery" 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.

[0070] The determination unit 53 determines whether the terminal device 10 is capable of simultaneous uplink transmission based on the interference information notified by the notification unit 15 of the terminal device 10. The determination unit 53 determines that the terminal device 10 is capable of simultaneous uplink transmission when the comparison result of the comparison unit 13 of the terminal device 10 indicates, for example, that the interference level of the terminal device 10 is significantly smaller than the allowable value.

[0071] If the determining unit 53 determines that communication with a plurality of base station devices 50 is possible (simultaneous uplink transmission is possible), the transmitting unit 55 transmits a response to that effect.

[0072] The transmitter 55 transmits various setting information for simultaneous uplink transmission of the terminal device 10 to the terminal device 10. Furthermore, when the transmitter 55 determines that simultaneous uplink transmission is possible, the transmitter 55 shares various setting information (e.g., CA setting information) for simultaneous uplink transmission of the terminal device 10 with other base station devices. Furthermore, the transmitter 55 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.

[0073] The query unit 51, the determination unit 53, and the transmission unit 55 may be realized by, for example, the communication device 24 shown in FIG. 2 , 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.

[0074] <Radio Signal Transmission Processing> (First Example) A first example of radio signal transmission processing of a terminal device according to an embodiment will be described with reference to FIG. 5 . The first example of radio signal transmission processing is an example in which, as a premise, multiple base station devices 50-1...50-n support a non-collocated scenario, and the terminal device 10 also supports the non-collocated scenario. Furthermore, an RRC connection is established between the terminal device 10 and the base station device 50. For example, the terminal device 10 and the base station device 50 transmit and receive RRC messages in the RRC layer, and proceed with session processing (also referred to as a connection sequence). The prerequisites for the first example of radio signal transmission processing described above also apply to second and third examples of radio signal transmission processing described below.

[0075] As shown in FIG. 5, for example, a base station device 50-1 (one of the base station devices) among the multiple base station devices 50 transmits a "UECapabilityQuery" to the terminal device 10 to inquire about the terminal capability information "UECapabilityInformation" of the terminal device 10 (step S1).

[0076] When the terminal device 10 receives an inquiry ("UECapabilityInquiry") from the base station device 50-1, it compares the interference level indicating the degree of interference of the terminal device 10 (for example, EL shown in Figure 8: actual emission level of the terminal device) with a predetermined threshold value (for example, "tolerance value" shown in Figure 8) (step S2).

[0077] Specifically, in response to an inquiry from the base station device 50-1, the terminal device 10 returns (notifies) its own terminal capability information "UECapabilityInformation" to the base station device 50-1 (step S3A). The terminal device 10 compares an interference level indicating the degree of interference of the terminal device 10 with a predetermined threshold, and notifies the base station device 50 of the comparison result as terminal capability information I1. In addition, the terminal device 10 transmits information regarding at least one of Intra-band EN-DC and Intra-band NR CA that it supports to the base station device 50-1.

[0078] The base station device 50-1 determines whether the terminal device 10 is capable of simultaneous uplink transmission based on the interference information included in the terminal capability information of the terminal device 10 received from the terminal device 10 (step S4A).

[0079] The base station device 50-1 can communicate with other base station devices 50-n that support the non-co-location scenario. Therefore, the base station device 50-1 transmits (shares) to the other base station devices 50-n various setting information for simultaneous uplink transmission of the terminal device 10 and information that the terminal device 10 is capable of simultaneous uplink transmission (step S5).

[0080] The base station device 50-1 may share the setting information with the other base station devices 50-n at any timing. The setting information and the determination result may be transmitted to the other base station devices 50-n at each timing set and generated by the base station device 50-1, or may be transmitted in response to a request from the other base station devices 50-n.

[0081] If the terminal device 10 is capable of simultaneous uplink transmission, the base station device 50-1 transmits the determination result to the terminal device 10 (step S6). The base station device 50-1 transmits various setting information for simultaneous uplink transmission of the terminal device 10 to the terminal device 10.

[0082] Upon receiving various information from the base station device 50-1, the terminal device 10 executes simultaneous uplink transmission (steps S7 and S8). As described above, the base station device 50-1 shares the setting information and determination results with the other base station devices 50-n. Therefore, the other base station devices 50-n can receive radio signals from the terminal device 10 based on the setting information for simultaneous uplink transmission set by the base station device 50-1, just like the base station device 50-1.

[0083] As described above, according to the first example of the radio signal transmission processing, the terminal device 10 includes a receiving unit 11 that receives an inquiry from one of the multiple base station devices 50, and a notification unit 15 that, when the terminal device 10 is capable of communicating with the multiple base station devices 50 located at different locations, notifies the one base station device of interference information regarding interference between radio signals when the terminal device 10 transmits radio signals to each of the multiple base station devices 50 located at different locations based on the inquiry.

[0084] In this way, the base station device can obtain, through an inquiry, interference information regarding interference between radio signals when a terminal device transmits radio signals to each of multiple base station devices located at different locations. Therefore, the base station device can perform appropriate scheduling based on the obtained interference information. Therefore, it is possible to improve the utilization efficiency of radio communication resources between the terminal device and the base station device. Furthermore, because appropriate scheduling is performed, it is possible to improve the throughput of uplink communication for the terminal device.

[0085] (Second Example) A second example of the radio signal transmission process of the terminal device according to the embodiment will be described with reference to Fig. 6. In the second example of the radio signal transmission process, the terminal device 10 notifies the base station device 50-1 of the emission level (interference level) of the terminal device 10 as terminal capability information in addition to the comparison result of the comparator 13. Below, differences from the first example of the radio signal transmission process will be particularly described.

[0086] As shown in FIG. 6, the terminal device 10 notifies the base station device 50-1 of the comparison result of the comparison unit 13 and the terminal capability information I2 including the emission level of the terminal device 10 (step S3B).

[0087] The base station device 50-1 determines whether or not the terminal device 10 is capable of simultaneous uplink transmission based on the comparison result of the comparator 13 and the emission level of the terminal device 10 (step S4B).

[0088] According to the second example of the wireless signal transmission processing, the base station device 50-1 determines whether or not the terminal device 10 is capable of simultaneous uplink transmission, taking into account the emission level of the terminal device 10 in addition to the comparison result of the comparator 13. Therefore, the terminal device 10 can further refer to the actual emission level of the terminal device 10, and can therefore more accurately determine whether or not the terminal device 10 is capable of simultaneous uplink transmission.

[0089] (Third Example) A third example of the radio signal transmission processing of the terminal device according to the embodiment will be described with reference to Fig. 7. In the third example of the radio signal transmission processing, the terminal device 10 notifies the base station device 50-1 of information based on the interference level of the terminal device 10 and a predetermined threshold as terminal capability information, in addition to the comparison result of the comparator 13. Below, differences from the first example of the radio signal transmission processing will be particularly described.

[0090] As shown in Figure 7, the terminal device 10 notifies the base station device 50-1 of terminal capability information I3, which includes the comparison result of the comparison unit 13 and information based on the interference level of the terminal device 10 and a predetermined threshold (for example, information regarding at least one of the difference and ratio between the emission level of the terminal device 10 and the allowable value) (step S3C).

[0091] The base station device 50-1 determines whether the terminal device 10 is capable of simultaneous uplink transmission based on the comparison result of the comparator 13 and information based on the emission level of the terminal device 10 and a predetermined threshold (step S4C).

[0092] According to the third example of the wireless signal transmission processing, the base station device 50-1 determines whether the terminal device 10 is capable of simultaneous uplink transmission based on information based on the interference level of the terminal device 10 and a predetermined threshold in addition to the comparison result of the comparator 13. Therefore, the terminal device 10 can further refer to information on at least one of the difference and ratio between the emission level of the terminal device 10 and the allowable value, for example, and therefore can more accurately determine whether the terminal device 10 is capable of simultaneous uplink transmission.

[0093] 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.

[0094] The determination unit 53 shown in Fig. 4 may further include functions related to the comparison unit 13 of the terminal device 10 shown in Fig. 3. The determination unit 53 may acquire information on an interference level indicating the degree of interference of the terminal device 10 from the terminal device 10, and compare the acquired interference level of the terminal device 10 with a predetermined threshold. Then, the determination unit 53 may determine whether or not the terminal device 10 is capable of simultaneous uplink transmission based on the comparison result between the interference level of the terminal device 10 and the predetermined threshold.

[0095] 10 (10-1...10-m)...terminal device, 11...receiving unit, 13...comparison unit, 15...notification unit, 17...transmission 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...determination unit, 55...transmission unit, 90...core network device, 100...wireless communication system

Claims

1. A terminal device capable of wireless communication with a plurality of base station devices, a receiving unit that receives an inquiry from one of the plurality of base station devices; a notification unit that notifies the one base station device of interference information regarding interference between radio signals caused by a radio signal transmitted by the terminal device when the terminal device transmits a radio signal to each of the plurality of base station devices that are located at different positions based on the inquiry, when the terminal device is capable of communicating with the plurality of base station devices that are located at different positions; A terminal device comprising:

2. A comparison unit that compares an interference level indicating the degree of interference of the terminal device with a predetermined threshold value, The notification unit notifies the comparison result as the interference information when the comparison result by the comparison unit satisfies a predetermined condition. The terminal device according to claim 1 .

3. the predetermined threshold is transmitted to the terminal device as a broadcast signal from at least one base station device of the plurality of base station devices; The terminal device according to claim 2.

4. The notification unit notifies an interference level indicating a degree of the interference of the terminal device as the interference information. The terminal device according to claim 1 .

5. The notification unit notifies, as the interference information, information based on an interference level indicating the degree of interference of the terminal device and a predetermined threshold value. The terminal device according to claim 1 .

6. A wireless communication method executed by a terminal device capable of wireless communication with a plurality of base station devices, comprising: receiving an inquiry from one of the plurality of base station devices; when the terminal device is capable of communicating with the plurality of base station devices arranged at different positions, notifying the one base station device of interference information regarding interference between radio signals caused by the radio signals transmitted by the terminal device when the terminal device transmits radio signals to each of the plurality of base station devices arranged at different positions based on the inquiry; A wireless communication method comprising: