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

Technical Field

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

Background Art

[0002] In the 3GPP (Third Generation Partnership Project), which is an international standardization organization, a new radio access technology NR (New Radio) for the fifth-generation (5G: Fifth Generation) cellular communication system is being studied. NR is being studied for technologies that enable a wider variety of services than LTE (Long Term Evolution)-Advanced, which is a fourth-generation cellular communication system. For example, in NR, usage scenarios with different applications, such as eMBB (enhanced Mobile Broad Band) for high-speed and high-capacity communication, URLLC (Ultra-Reliable and Low Latency Communication) for ultra-high reliability and low latency communication, and mMTC (massive Machine Type Communication) for enabling simultaneous connections of a large number of IoT (Internet of Things) devices, are defined as implementation requirements.

[0003] In NR, Carrier Aggregation (CA), which allows for bandwidth expansion by aggregating multiple frequency bands, such as 20 MHz, called Component Carriers (CC), is employed (see Non-Patent Document 1). Furthermore, NR employs EN-DC (E-UTRA-NR Dual Connectivity) using base station equipment eNB (evolved NodeB) in E-UTRA (Evolved Universal Terrestrial Radio Access) and base station equipment gNB (g-NodeB) in NR (see Non-Patent Document 2). Regarding EN-DC, two scenarios are known: the Collocated scenario, in which eNBs and gNBs located at the same location communicate with terminal equipment, and the Non-collocated scenario, in which eNBs and gNBs located at different locations communicate with terminal equipment.

[0004] Furthermore, in NR, in Intra-band EN-DC and Intra-band NR CA, terminal devices support a joint deployment scenario as Type 1 UEs. In addition, in Intra-band EN-DC, terminal devices support a non-joint deployment scenario where a 2x2 MIMO method (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, terminal devices (Type 2 UEs) that support the non-joint deployment scenario notify the base station equipment of this fact by including it in the terminal capability information "UECapabilityInformation" of the terminal device (see Non-Patent Document 1).

[0005] In wireless communication systems employing non-shared deployment scenarios, the distance between a terminal device and multiple base station devices located at different locations varies. The terminal device controls its transmit power for transmitting radio signals to each base station device located at a different location, depending on these distances. Therefore, the transmit power used when a terminal device transmits a radio signal to one base station device differs from the transmit power used when transmitting radio signals to other base station devices. For example, a higher power signal is transmitted when a terminal device transmits a radio signal to base station device A located at a distance A greater than the distance B from the terminal device, compared to when a 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 a distance A from the terminal device, leaks to other frequencies (emission), causing significant interference to the low-power radio signal, i.e., the radio signal transmitted to base station device B located at a distance B from the terminal device.

[0006] Incidentally, Non-Patent Document 4 specifies the permissible emission level for terminal devices. Specifically, Non-Patent Document 4 states that when a terminal device performs wireless communication using a frequency exceeding 1 GHz, emissions up to -30 dBm / MHz are permissible. [Prior art documents] [Patent Documents]

[0007] [Non-Patent Document 1] 3GPP standard document “TS 38.306 Ver.16.7.0 (2021-12)” [Non-Patent Document 2] 3GPP standard document “TS 37.340 Ver.16.8.0 (2021-12)” [Non-Patent Document 3] 3GPP standard document “TS 38.133 Ver.17.5.0 (2022-04)” [Non-Patent Document 4] 3GPP standard document “TS 38.101-1 Ver.17.6.0 (2022-06)” [Overview of the project] [Problems that the invention aims to solve]

[0008] However, in conventional wireless communication systems, base station equipment only possesses information regarding the permissible emission levels of terminal equipment. The base station equipment cannot obtain interference information regarding interference between radio signals when transmitting radio signals to multiple base station equipment located at different locations from the terminal equipment with which it can actually communicate. Therefore, conventional communication methods cannot perform appropriate scheduling based on interference information regarding terminal equipment. Consequently, the efficiency of utilizing wireless communication resources between terminal equipment and base station equipment may decrease.

[0009] This invention has been made in view of these circumstances, and aims to provide a wireless communication technology for improving the utilization efficiency of wireless communication resources between terminal devices and base station devices. [Means for solving the problem]

[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, comprising: 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 one of the base station devices of interference information regarding interference between radio signals when the terminal device transmits a radio signal 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 performed 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 radio signals when the terminal device transmits radio signals to each of the plurality of base station devices located at different locations, based on the inquiry. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a wireless communication technology for improving the utilization efficiency of wireless communication resources between terminal devices and base station devices. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a diagram showing an example of the schematic configuration of a wireless communication system in an embodiment. [Figure 2] Figure 2 is a configuration diagram showing an example of the hardware configuration of the terminal device and base station device in the embodiment. [Figure 3] Figure 3 is a configuration diagram showing an example of the functional block configuration of a terminal device in an embodiment. [Figure 4] Figure 4 is a configuration diagram showing an example of the functional block configuration of a base station device in an embodiment. [Figure 5] Figure 5 is a flowchart showing an example of the wireless signal transmission process of a terminal device in an embodiment. [Figure 6] Figure 6 is a flowchart showing an example of the wireless signal transmission process of a terminal device in an embodiment. [Figure 7] Figure 7 is a flowchart showing an example of the wireless signal transmission process of a terminal device in an embodiment. [Figure 8] Figure 8 shows an example of interference between radio signals when a terminal device transmits radio signals to each of multiple base station devices located at different locations in an embodiment.

Embodiments for Carrying Out the Invention

[0014] Embodiments of the present invention will be described below. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, the drawings are schematic. Therefore, specific dimensions and the like should be determined in light of the following description. Also, it is a matter of course that there are parts where the dimensional relationships and ratios are different between the drawings. Furthermore, the technical scope of the present invention should not be construed as being limited to the embodiments.

[0015] Referring to FIG. 1, the schematic configuration of the wireless communication system in the embodiment will be described. FIG. 1 is a configuration diagram showing an example of the schematic configuration of the wireless communication system 100. The wireless communication system 100 includes 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 targeting NR (New Radio). Note that the present invention is applicable to any wireless communication system including at least a terminal device and a base station device, and is not limited to those targeting NR. For example, the present invention is also applicable to LTE and LTE-Advanced. Also, the present invention is applicable to a wireless communication system that uses NR in part of the wireless communication system.

[0016] Hereinafter, LTE and LTE-Advanced are also referred to as E-UTRA (Evolved Universal Terrestrial Radio Access). The area (coverage area) formed by the base station device is called a cell, and E-UTRA and NR are cellular communication systems constructed by a plurality of cells. The wireless communication system according to the present embodiment may apply either the TDD (Time Division Duplex) or FDD (Frequency Division Duplex) method, and different methods may be applied for each cell.

[0017] Terminal devices 10-1 to 10-m are each wirelessly connected to any one of base station devices 50-1 to 50-n. Also, each of terminal devices 10-1 to 10-m may be wirelessly connected to two or more of base station devices 50-1 to 50-n simultaneously. Each of base station devices 50-1 to 50-n can 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).

[0018] Wireless communication system 100 is, for example, a wireless communication system compatible with carrier aggregation (CA) and E-UTRA-NR dual connectivity (EN-DC). Carrier aggregation refers to a process in which component carriers (CCs), for example, frequency bands of 20 MHz, are aggregated (bundled) to enable bandwidth expansion.

[0019] In EN-DC (E-UTRA-NR dual connectivity), base station device eNB and base station device gNB can cooperate to communicate with terminal device 10. For example, a scenario in which an eNB and a gNB arranged at the same location communicate with terminal device 10 is called a collocated scenario, and a scenario in which an eNB and a gNB arranged at different locations communicate with terminal device 10 is called a non-collocated scenario.

[0020] Herein, an overview of the wireless communication system 100 in an embodiment of the present invention will be described below. Figure 8 is a diagram showing an example of interference between radio signals when a terminal device transmits a radio signal to each of a plurality of base station devices located at different locations in an embodiment. For example, the transmit power output P1 when a terminal device transmits a radio signal at frequency F1 to a base station device A located at a distance A greater than the distance B from the terminal device is higher than the transmit power output P2 when a terminal device transmits a radio signal at frequency F2 to a base station device B located at a distance B from the terminal device.

[0021] As described above, in conventional wireless communication systems, the base station equipment only possesses information regarding the permissible emission levels of the terminal equipment. Therefore, if the actual emission level EL of the transmit power output P2 at frequency F2 is approximately the same as the permissible emission level AL, or if it is below the permissible emission level AL but not significantly lower than AL, the base station equipment will determine that the transmit power output P2 will be greatly affected by interference with the transmit power output P1 (the transmit power output P2 will be overwhelmed by interference), and will not allow simultaneous uplink transmission from multiple carriers (multiple terminal equipment).

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

[0023] Therefore, the terminal device in the embodiment of the present invention is a terminal device capable of wireless communication with a plurality of base station devices, comprising: a receiving unit that receives an inquiry regarding capability information of the terminal device from one of the plurality of base station devices; and a notification unit that, when the terminal device is capable of communicating with a plurality of base station devices located at different locations, notifies one of the base station devices 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, based on the inquiry.

[0024] Thus, the base station equipment can obtain interference information regarding interference between radio signals when a terminal device transmits radio signals to multiple base station equipment located at different locations, by querying the base station equipment. Therefore, the base station equipment can perform appropriate scheduling based on the acquired interference information. Consequently, it is possible to improve the utilization efficiency of wireless communication resources between the terminal device and the base station equipment. Furthermore, because appropriate scheduling is performed, the uplink communication throughput of the terminal device can be improved. For this reason, the technology according to this embodiment can contribute to achieving Sustainable Development Goal (SDG) 9, "Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation."

[0025] The following describes in detail each component of the wireless communication system 100. Figure 1 shows terminal devices 10-1 to 10-m as m units (where m is an integer of 2 or more). In the following description, when these m units of terminal devices are described without distinction, some of the symbols will be omitted and they will simply be referred to as "terminal device 10". Also, Figure 1 shows base station devices 50-1 to 50-n as n units (where n is an integer of 2 or more). In the following description, when these n units of base station devices are described without distinction, some of the symbols will be omitted and they will simply be referred to as "base station device 50". Terminal devices in E-UTRA and NR are called UE (User Equipment). Base station device gNB in ​​NR may be connected to terminal devices using a portion of the frequency band it uses (BWP: Carrier bandwidth part). In the following, when referred to as a cell, it will include the BWP.

[0026] Examples of portable information and communication devices include 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 the base station device 50 on a cell-by-cell basis, or it may be connected using multiple cells, such as carrier aggregation. When the terminal device 10 is connected via multiple base station devices, that is, in the case of DC (Dual Connectivity), the base station device to which it is initially connected is called the master node (MN), and the base station devices to which it is additionally connected are called secondary nodes (SN). The base station devices are connected to each other by base station interfaces. In addition, the base station device 50 and the core network device 90 are connected by a core interface. The base station interface is used to exchange control signals necessary for handover and coordinated operation between base station devices.

[0027] The core network device 90, for example, has base station devices 50 under its control and primarily handles load control between base station devices, calling (paging) terminal devices 10, and mobility control such as location registration. In NR, the core network device 90 defines the Access and Mobility Management Function (AMF) for managing mobility and the Session Management Function (SMF) for managing sessions as a set of control plane (C-plane) functions. E-UTRA defines the Mobility Management Entity (MME) corresponding to the AMF.

[0028] Although Figure 1 shows an example where the core network device 90 consists of a single device, it is not limited to this. For example, the core network device may include servers, gateways, etc., and may consist of multiple devices.

[0029] The terminal device 10 and the base station device 50 communicate via radio resource control (RRC) messages at the RRC layer to proceed with session processing (also called a connection sequence). As session processing progresses, the terminal device 10 changes from an idle state (RRC Idle) to a connected state to the base station device 50 (RRC Connected). The idle state corresponds to the waiting 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) at the Medium Access Control (MAC) layer. RRC messages are transmitted as RRC PDUs (Protocol Data Units). Common Control Channels (CCCH), Dedicated Control Channels (DCCH), Paging Control Channels (PCCH), Broadcast Control Channels (BCCH), or Multicast Control Channels (MCCH) are used as the mapped logical channels. MAC CEs are transmitted as MAC PDUs (or MAC subPDUs). A MAC subPDU is equivalent to a Service Data Unit (SDU) at the MAC layer with, for example, an 8-bit header added, and a MAC PDU contains one or more MAC subPDUs.

[0031] A physical channel and physical signal relating to one embodiment of the present invention will be described below. Among the physical channels relating to the embodiment of the present invention, the Physical Broadcast Channel (PBCH), Primary Synchronization Signal (PSS), Secondary Synchronization Signal (SSS), Physical Random Access Channel (PRACH), and Physical Downlink Control Channel (PDCCH) will be described below.

[0032] In addition, the wireless communication system according to this embodiment also includes 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 a detailed explanation is omitted.

[0033] <Physical Notification Channel (PBCH)> The Physical Broadcast Channel (PBCH) is transmitted from the base station equipment 50 to the terminal equipment 10 and is used to notify common parameters (system information) in the cells under the base station equipment 50. The system information is further classified into Master Information Blocks (MIBs) and System Information Blocks (SIBs). The System Information Blocks are further subdivided and transmitted as SIB1, SIB2, etc.

[0034] System information includes the information necessary to connect to a cell. For example, the MIB contains the system frame number and information indicating whether camp-on to the cell is possible. The SIB1 also contains parameters for calculating cell quality (cell selection parameters), common channel information for cells (random access control information, PUCCH control information, PUSCH control information), and scheduling information for other system information.

[0035] The physical broadcast channel (PBCH) is periodically transmitted as a synchronization signal block (SSB: Synchronization Signal Block (or SS / PBSH)) in conjunction 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 obtain cell identifier (cell ID) information and reception timing, as well as measure the signal quality of the cell in question.

[0036] System information notified via a physical broadcast channel (PBCH), etc., is also called "system broadcast information" or "broadcast information." Camping on to a cell means that the terminal device 10 has completed cell selection and / or cell reselection, and has selected a cell to monitor system broadcast information and paging information. The terminal device 10 establishes the aforementioned 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 received symbol timing and frequency of the downlink signal from 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 a cell on the base station device 50 (hereinafter also referred to as the "cell search procedure"). Based on the physical cell ID, three types of signals, "0" to "2", are repeatedly used for the Primary Synchronization Signal (PSS). The physical cell ID is an identifier for a physical cell; 504 types of IDs are used in E-UTRA, and 1008 types of 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 used by the terminal device 10 to detect the physical cell ID during the cell search procedure. Based on the physical cell ID, 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.

[0039] <Physical Random Access Channel (PRACH)> A 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 when uplink synchronization has not been 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 available radio resources for transmitting the random access preamble is transmitted to the terminal using broadcast information or RRC messages.

[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 it of Downlink Control Information (DCI). The Downlink Control Information includes radio resource information for the uplink available to the terminal device 10 (Uplink Grant (UL grant)) or radio resource information for the downlink (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 as a 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 the index information of the random access preamble, transmission timing adjustment information, and the Uplink Grant.

[0041] <Hardware Configuration> Referring to Figure 2, the hardware configuration of the terminal device and base station device in one embodiment will be described. Figure 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 Figure 2, the terminal device 10 and the base station device 50 each include, for example, a processor 21, memory 22, storage device 23, communication device 24, input device 25, output device 26, antenna 27, and sensor 29.

[0043] The processor 21 is configured to control the operation of various parts of the terminal device 10 or base station device 50. The processor 21 is composed of integrated circuits such as a CPU (Central Processing Unit), DSP (Digital Signal Processor), ASIC (Application Specific Integrated Circuit), PLD (Programmable Logic Device), FPGA (Field Programmable Gate Array), and SoC (System-on-a-chip).

[0044] The memory 22 and the storage device 23 are configured to store programs, data, etc. The memory 22 consists of, for example, ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), and / or RAM (Random Access Memory). The storage device 23 consists of, for example, HDD (Hard Disk Drive), SSD (Solid State Drive), and / or eMMC (embedded Multi Media Card).

[0045] The communication device 24 is configured to communicate via wired and / or wireless networks. The communication device 24 includes, for example, a network card, a communication module, etc. Furthermore, the communication device 24 may also include, exemplary, an amplifier, an RF (Radio Frequency) front-end 243 for processing wireless signals, and a signal processing unit 241 for processing baseband signals.

[0046] The RF front-end 243 generates a radio signal to be transmitted from the antenna 27 by 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 generates a digital baseband signal by performing frequency conversion, demodulation, A / D (Analog to Digital) conversion, etc., on the radio signal received from the antenna 27 and transmits it to the signal processing unit 241. The signal processing unit 241 performs processing to convert the digital baseband signal into an IP packet, and processing to convert the IP packet into a digital baseband signal.

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

[0048] The output device 26 is configured to output information. The output device 26 includes, for example, a display device such as a liquid crystal display, an EL (Electro Luminescence) display, or a plasma display, and / or a speaker.

[0049] Antenna 27 is configured to radiate and receive radio waves (electromagnetic waves) in one or more predetermined frequency bands. Antenna 27 may be a directional antenna. A directional antenna 27 has different gains depending on the orientation of the antenna. Antenna 27 may also be non-directional, i.e., omnidirectional. An omnidirectional antenna 27 has approximately equal gains from all 360 degrees in the horizontal plane, the vertical plane, or both horizontal and vertical planes.

[0050] The antenna 27 is not limited to being a single antenna. The terminal device 10 and the base station device 50 may be equipped with multiple antennas. As described above, each of the terminal device 10 and the base station device 50 is equipped with multiple antennas to enable the use of 2x2 MIMO and 4x4 MIMO systems. When the terminal device 10 and the base station device 50 are equipped with multiple antennas, they may be divided into, for example, transmitting antennas and receiving antennas. Also, when multiple antennas are divided into transmitting antennas and receiving antennas, at least one of them may include multiple antennas. Furthermore, when the terminal device 10 and the base station device 50 are equipped with multiple transmitting and receiving antennas or transmitting antennas, the beamforming technology described above can be used.

[0051] The sensors 29 provided by the terminal device 10 include sensors for detecting the position, orientation, and acceleration of the terminal device 10. The sensors 29 provided by the terminal device 10 include, for example, at least one of the following sensors: a GPS (Global Positioning System) sensor, a gyroscope sensor, and an acceleration sensor. On the other hand, the sensors 29 provided by the base station device 50 may include, for example, sensors for detecting environmental information such as temperature, humidity, weather, or seismic intensity at the base station device 50.

[0052] <Functional Block Configuration> (Terminal device) Referring to Figure 3, the functional block configuration of the terminal device in this embodiment will be described. Figure 3 is a configuration diagram showing an example of the functional block configuration of the terminal device 10. Note that Figure 3 is intended to show the functional blocks necessary for describing this embodiment and does not exclude the possibility that the terminal device 10 may have functional blocks other than those shown.

[0053] The terminal device 10 includes, as an example of a functional block, a receiving unit 11, a comparison unit 13, a notification unit 15, and a transmission unit 17.

[0054] The receiving unit 11 receives various information from the base station device 50 shown in Figure 1. For example, the receiving unit 11 receives inquiries from the base station device 50 regarding terminal capability information of the terminal device 10. As shown in Figures 5 to 7 described later, the terminal capability information includes, for example, "UECapabilityInformation," and inquiries regarding terminal capability information include "UECapabilityEnquriry."

[0055] The receiving unit 11 receives a response from the base station device 50 (determination unit 53 shown in Figure 4) if it determines that communication with the base station device 50 is possible (uplink simultaneous transmission is possible).

[0056] The receiving unit 11 may receive radio signals transmitted by the base station device 50 using a MIMO scheme set based on terminal capability information related to the MIMO scheme, for example. Once a MIMO scheme suitable for the terminal capability of the terminal device 10 is set, the base station device 50 performs success control processing (e.g., CA processing and MIMO processing) to transmit radio signals to the terminal device 10. The receiving unit 15 receives the radio signals transmitted after the success control processing by the base station device 50 has been performed.

[0057] The comparison unit 13 compares the interference level (for example, EL shown in Figure 8: the actual emission level of the terminal device) which indicates the degree of interference of the terminal device 10 with a predetermined threshold (for example, the "tolerance value" shown in Figure 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 rule out the possibility that the "emission level" may fluctuate depending on the actual communication conditions. The actual "emission level" of the terminal device 10 is set, for example, based on the parts and materials (for example, amplifiers and filters) used in the manufacturing process of the terminal device.

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

[0059] The notification unit 15 notifies the base station device 50 of various information in response to inquiries from the base station device 50. For example, the notification unit 13 replies (notifies) the base station device 50 of "UECapabilityInformation" based on the "UECapabilityEnquriry" 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, which compares 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 also notify the comparison result as terminal capability information if the comparison result obtained by the comparison unit 13 satisfies predetermined conditions. 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 conditions" include conditions relating to at least one of the difference and ratio between the interference level of the terminal device 10 and the allowable value. The "predetermined conditions" include, for example, that the difference (absolute value) between the interference level of the terminal device 10 and the allowable value is greater than the set value (for example, that the interference level of the terminal device 10 is significantly smaller than the allowable value).

[0062] The notification unit 15 may notify the interference level, which indicates the degree of interference from the terminal device 10, as interference information. The notification unit 15 may also notify information based on the interference level of the terminal device 10 and an acceptable value (a predetermined threshold) (e.g., -30 dBm / MHz) as interference information. The information based on the interference level of the terminal device 10 and the acceptable value includes, for example, information regarding at least one of the difference and ratio between the interference level of the terminal device 10 and the acceptable value.

[0063] Furthermore, the notification unit 15 only needs to be able to notify the base station device 50 of usable information, and the form of notification is arbitrary. The notification unit 15 is not limited to notifying interference information as "UECapabilityInformation," but may also notify usable information as other information.

[0064] The transmitting unit 17 transmits a radio signal to the base station device 50. Based on the response from the terminal device 50 that simultaneous uplink transmission is possible, the transmitting unit 17 performs simultaneous uplink transmission.

[0065] Furthermore, the transmitting unit 17 dynamically changes the bands that can be transmitted simultaneously in carrier aggregation based on the radio resources allocated from the base station equipment 50, for example, and transmits radio signals. The transmitting unit 17 also performs success control processing (e.g., CA processing and MIMO processing) for transmitting radio signals from the terminal equipment 10 to the base station equipment 50.

[0066] The receiving unit 11, the comparison unit 13, the notification unit 15, and the transmitting unit 17 may be implemented by, for example, the communication device 24 shown in Figure 2, or by the processor 21 executing a program stored in the storage device 23 in addition to the communication device 24. 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, but may be, for example, a USB (Universal Serial Bus) memory or a CD-ROM (Compact Disc ROM).

[0067] (Base station equipment) Referring to Figure 4, the functional block configuration of the base station device in this embodiment will be described. Figure 4 is a configuration diagram showing an example of the functional block configuration of the base station device 50. Note that Figure 4 is intended to show the functional blocks necessary for describing this embodiment and does not exclude the possibility that the base station device 50 may have functional blocks other than those shown.

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

[0069] The inquiry unit 51 sends a "UECapabilityEnquriry" to query the terminal capability information "UECapabilityInformation" of the terminal device 10. The inquiry unit 51 receives the terminal capability information provided in response from the terminal device 10.

[0070] The determination unit 53 determines whether the terminal device 10 is capable of simultaneous uplink transmission based on 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 if, for example, the comparison result of the comparison unit 13 of the terminal device 10 is significantly smaller than the allowable value of the interference level of the terminal device 10.

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

[0072] The transmitting unit 55 transmits various setting information for simultaneous uplink transmission of the terminal device 10 to the terminal device 10. Furthermore, if the transmitting unit 55 determines that simultaneous uplink transmission is possible, it shares the various setting information for simultaneous uplink transmission of the terminal device 10 (e.g., CA setting information) with other base station devices. In addition, the transmitting unit 55 performs 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 inquiry unit 51, determination unit 53, and transmission unit 55 may be implemented by, for example, the communication device 24 shown in Figure 2, or by the processor 21 executing a program stored in the storage device 23 in addition to the communication device 24. 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-temporary storage medium. The non-temporary storage medium is not particularly limited, but may be, for example, a USB memory or a CD-ROM.

[0074] <Wireless signal transmission processing> (Example 1) Referring to Figure 5, a first example of the wireless signal transmission process of a terminal device according to the embodiment will be described. The first example of the wireless signal transmission process assumes that, in addition to the fact that multiple base station devices 50-1...50-n support a non-collocated scenario, the terminal device 10 also supports a non-collocated scenario. Furthermore, an RRC connection is established between the terminal device 10 and the base station devices 50. For example, the terminal device 10 and the base station devices 50 send and receive RRC messages at the RRC layer and proceed with session processing (also called a connection sequence). The preconditions for the first example of the wireless signal transmission process described above are similarly applied to the second and third examples of the wireless signal transmission process described later.

[0075] As shown in Figure 5, one of the multiple base station devices 50, for example, base station device 50-1 (one base station device), sends a "UECapabilityEnquriry" to the terminal device 10 to query the terminal capability information "UECapabilityInformation" of the terminal device 10 (step S1).

[0076] When terminal device 10 receives an inquiry ("UECapabilityEnquriry") from base station device 50-1, it compares the interference level (e.g., EL shown in Figure 8: actual emission level of terminal device) which indicates the degree of interference of terminal device 10 with a predetermined threshold (e.g., "acceptable 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 sends back (notifies) its own terminal capability information "UECapabilityInformation" to the base station device 50-1 (step S3A). The terminal device 10 notifies the base station device 50 of the comparison result, which is obtained by comparing the interference level indicating the degree of interference of the terminal device 10 with a predetermined threshold, as terminal capability information I1. The terminal device 10 also transmits to the base station device 50-1 information regarding at least one of the Intra-band EN-DC and Intra-band NR CA that it supports.

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

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

[0080] The timing at which base station device 50-1 shares configuration information with other base station devices 50-n is arbitrary. The configuration information and determination results may be transmitted to other base station devices 50-n at each timing set and generated by base station device 50-1, or they may be transmitted in response to requests from other base station devices 50-n.

[0081] The base station device 50-1 transmits the determination result to the terminal device 10 if the terminal device 10 is capable of simultaneous uplink transmission (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] When terminal device 10 receives various information from base station device 50-1, it performs simultaneous uplink transmission (steps S7 and S8). As described above, the base station device 50-1 shares the configuration information and determination results with other base station devices 50-n. Therefore, other base station devices 50-n can receive radio signals from terminal device 10 based on the configuration information for simultaneous uplink transmission set by base station device 50-1, just like base station device 50-1.

[0083] According to the first example of wireless signal transmission processing described above, 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, if the terminal device 10 can communicate with multiple base station devices 50 located at different locations, notifies one of the base station devices of interference information regarding interference between wireless signals when the terminal device 10 transmits a wireless signal to each of the multiple base station devices 50 located at different locations, based on the inquiry.

[0084] Thus, the base station equipment can obtain interference information regarding interference between radio signals when a terminal device transmits radio signals to multiple base station equipment located at different locations, through queries. Therefore, the base station equipment can perform appropriate scheduling based on the acquired interference information. Consequently, it is possible to improve the utilization efficiency of wireless communication resources between the terminal device and the base station equipment. Furthermore, because appropriate scheduling is performed, the uplink communication throughput of the terminal device can be improved.

[0085] (Example 2) Referring to Figure 6, a second example of the wireless signal transmission process of the terminal device according to the embodiment will be described. In the second example of the wireless 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 comparison unit 13. The following will specifically describe the points that differ from the first example of the wireless signal transmission process.

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

[0087] 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 comparison unit 13 and the emission level of the terminal device 10 (step S4B).

[0088] According to the second example of wireless signal transmission processing, the base station device 50-1 determines whether 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 comparison unit 13. Therefore, the terminal device 10 can further refer to its actual emission level, making it possible to determine more accurately whether the terminal device 10 is capable of simultaneous uplink transmission.

[0089] (Example 3) Referring to Figure 7, a third example of the wireless signal transmission process of the terminal device according to the embodiment will be described. In the third example of the wireless signal transmission process, 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, in addition to the comparison result of the comparison unit 13, as terminal capability information. The following will specifically describe the differences from the first example of the wireless signal transmission process.

[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 from 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 comparison unit 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 wireless signal transmission processing, the base station device 50-1 determines whether the terminal device 10 is capable of simultaneous uplink transmission, taking into account information based on the interference level of the terminal device 10 and a predetermined threshold, in addition to the comparison result of the comparison unit 13. Therefore, the terminal device 10 can more accurately determine whether it is capable of simultaneous uplink transmission, for example, by further referring to information regarding at least one of the difference and ratio between the emission level of the terminal device 10 and the allowable value.

[0093] The above embodiments or examples are provided to facilitate understanding of the present invention and are not intended to limit it. The present invention can be modified or improved without departing from its spirit, and equivalents thereof are also included. Furthermore, the present invention can form various disclosures by appropriately combining the multiple components disclosed in the above embodiments or examples. For example, some components may be deleted from all the components shown in an embodiment. Moreover, components may be appropriately combined in different embodiments.

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

[0095] 10(10-1…10-m)…Terminal device, 11…Receiver, 13…Comparison unit, 15…Notification unit, 17…Transmitter, 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…Transmitter, 90…Core network device, 100…Wireless communication system

Claims

1. Multiple base station devices and terminal devices capable of wireless communication are arranged in different locations and cooperate with each other, A receiving unit that receives an inquiry from one of the aforementioned multiple base station devices, When the terminal device is able to communicate with the plurality of base station devices, a notification unit notifies one of the base station devices of interference information regarding interference between radio signals caused by the radio signals transmitted by the terminal device when the terminal device transmits a radio signal to each of the plurality of base station devices based on the inquiry, Equipped with, The notification unit notifies information based on an interference level indicating the degree of interference of the terminal device and a predetermined threshold, wherein the information provided is information relating to at least one of the difference and ratio between the interference level and the predetermined threshold, as interference information. Terminal device.

2. The terminal device further comprises a comparison unit that compares the interference level, which indicates the degree of interference, with a predetermined threshold value. The notification unit notifies the comparison result as interference information when the comparison result obtained by the comparison unit satisfies predetermined conditions. 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 of the multiple base station devices. The terminal device according to claim 2.

4. The notification unit notifies the interference level, which indicates the degree of interference of the terminal device, as interference information. The terminal device according to claim 1.

5. A wireless communication method performed by multiple base station devices and wireless communication terminal devices arranged at different locations and coordinating with each other, Receiving an inquiry from one of the aforementioned multiple base station devices, When the terminal device is able to communicate with the multiple base station devices, the terminal device transmits a radio signal to each of the multiple base station devices based on the inquiry, and the terminal device notifies one base station device of interference information regarding interference between radio signals caused by the radio signal transmitted by the terminal device. Includes, The notification includes providing information based on an interference level indicating the degree of interference of the terminal device and a predetermined threshold, wherein the notification includes information relating to at least one of the difference and ratio between the interference level and the predetermined threshold as interference information. Wireless communication method.

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