WO2021156994A1 - Terminal device, base station device, and wireless communication method - Google Patents

Abstract

A terminal device (10) that executes wireless communication with a base station device (50) via a specific frequency band for which a plurality of types have been preset in accordance with characteristics of beams for transmitting a signal from the terminal device (10) to the base station device (50), the terminal device being provided with: a beam control unit (17) that controls a beam generated on the basis of specific one of the types by changing the specific type to another one of the types; and a transmission unit (13) that transmits type information about the types to the base station device (50) when the beam is controlled. Thus, wireless communication technology for maintaining the stability of the wireless communication between the terminal device (10) and the base station device (50) can be provided.

Description

Terminal equipment, base station equipment, and wireless communication methods

The present invention relates to a terminal device, a base station device, and a wireless communication method.

The 3GPP (Third Generation Partnership Project), an international standardization organization, is studying NR (New Radio), which is a new wireless access technology for 5th generation (5G: Fifth Generation) cellular communication systems. For NR, a technology for realizing a wide variety of services is being studied, as compared with LTE (Long Term Evolution) -Advanced, which is a fourth-generation cellular communication system. For example, in NR, eMBB (enhanced Mobile Broad Band) that realizes high-speed and large-capacity communication, URLLC (Ultra-Reliable and Low Latency Communication) that realizes ultra-high reliability and low-delay communication, and IoT (Internet of Things) devices Usage scenarios with different uses, such as mMTC (massive Machine Type Communication) that realizes multiple simultaneous connections, are defined as realization requirements.

In NR, wireless communication using millimeter waves is feasible. When wireless communication is executed using a relatively high frequency band such as millimeter waves, propagation loss and the like increase. In order to prevent such a problem, a technique (beamforming) for forming a beam having a relatively narrow beam width is known (see Non-Patent Documents 1 and 2).

In NR, beamforming is executed based on a single power class defined for each terminal device type (UE type) (see Non-Patent Document 3).

3GPP standard "TS 38.321" 3GPP standard "TS 38.331" 3GPP standard "TS 38.306"

As mentioned above, in NR, a single power class is specified for each terminal device type. That is, it is not expected that the terminal device will support multiple power classes. Therefore, for example, when one terminal device supports a plurality of power classes, if beamforming is performed by switching the power classes without notifying the core network side in advance, the beam allowed for each power class is performed. The beam search cannot be properly executed in the base station device because the search time is different. Therefore, the communication connection between the terminal device and the base station device becomes unstable, and the stability in wireless communication may not be maintained.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a wireless communication technique for maintaining stability in wireless communication between a terminal device and a base station device.

The terminal device according to one aspect of the present invention is a terminal device that executes wireless communication with a base station device via a specific frequency band, and in a specific frequency band, a signal is transmitted from the terminal device to the base station device. A plurality of types are set in advance according to the characteristics of the beam for transmitting the beam, and a beam formed based on a specific type among the plurality of types can be used as a specific type and another type among the plurality of types. It is provided with a beam control unit that is controlled by changing to, and a transmission unit that transmits type information regarding a plurality of types to the base station apparatus when the beam is controlled.

The wireless communication method according to one aspect of the present invention is a wireless communication method used for a terminal device that executes wireless communication with a base station device via a specific frequency band, and a specific frequency band can be set from the terminal device. A plurality of types are set in advance according to the characteristics of the beam for transmitting a signal to the base station device, and a plurality of specific types of beams formed based on a specific type among the plurality of types are selected. This includes a step of controlling by changing to another type among the types of the above, and a step of transmitting type information regarding a plurality of types to the base station apparatus when controlling the beam.

The base station apparatus according to one aspect of the present invention is a base station apparatus that executes wireless communication with a terminal apparatus via a specific frequency band, and in a specific frequency band, the terminal apparatus to the base station apparatus. Multiple types are preset according to the characteristics of the beam for transmitting signals, and the receiver that receives type information related to the multiple types from the terminal device and the specific type among the multiple types in the terminal device The beam formed on the basis of the beam includes a transmission unit that transmits a request to be controlled by changing a specific type to another type among a plurality of types.

The wireless communication method according to one aspect of the present invention is a wireless communication method used for a base station device that executes wireless communication with a terminal device via a specific frequency band, and the terminal device can be used for a specific frequency band. A plurality of types are preset according to the characteristics of the beam for transmitting a signal to the base station device, and a step of receiving type information regarding the plurality of types from the terminal device and a step of receiving the type information regarding the multiple types in the terminal device and a plurality of types in the terminal device. The beam formed based on the specific type includes a step of transmitting a request to the terminal device for being controlled by changing the specific type to another type among a plurality of types.

According to the present invention, it is possible to provide a wireless communication technique for maintaining stability in wireless communication between a terminal device and a base station device.

FIG. 1 is a configuration diagram showing an example of a schematic configuration of a wireless communication system according to an embodiment. FIG. 2 is a configuration diagram showing an example of the hardware configuration of the terminal device and the base station device in one embodiment. FIG. 3 is a configuration diagram showing an example of the functional block configuration of the terminal device according to the embodiment. FIG. 4 is an explanatory diagram illustrating an example of a power class in one embodiment. FIG. 5 is an explanatory diagram illustrating an example of beam control processing performed by the terminal device in one embodiment. FIG. 6 is a configuration diagram showing an example of a functional block configuration of the base station apparatus in one embodiment. FIG. 7 is a time chart for explaining a first example of the procedure of beam control processing performed by the wireless communication system in one embodiment. FIG. 8 is a time chart for explaining a second example of the procedure of the beam control processing performed by the wireless communication system in one embodiment.

An embodiment of the present invention will be described below. In the description of the drawings below, the same or similar parts are represented by the same or similar reference numerals. However, the drawings are schematic. Therefore, the specific dimensions and the like should be determined in light of the following explanations. In addition, it goes without saying that the drawings include parts having different dimensional relationships and ratios from each other. Furthermore, the technical scope of the present invention should not be construed as limited to the embodiment.

The schematic configuration of the wireless communication system according to one embodiment will be described with reference to FIG. FIG. 1 is a configuration diagram showing an example of a schematic configuration of a wireless communication system 100 according to an embodiment.

As shown in FIG. 1, the wireless communication system 100 includes a terminal device 10-1 to a terminal device 10-m, a base station device 50-1 to a base station device 50-n, and a core network device 90. It is composed.

The wireless communication system 100 is, for example, a wireless communication system for NR. 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. It can also be applied to a wireless communication system that uses NR as a part of the wireless communication system. Hereinafter, LTE and LTE-Advanced are also referred to as E-UTRA (Evolved Universal Terrestrial Radio Access), but their meanings are the same. The area (cover area) formed by the base station apparatus is referred to as a cell, and E-UTRA and NR are cellular communication systems constructed by a plurality of cells. Either TDD (Time Division Duplex) or FDD (Frequency Division Duplex) may be applied to the wireless communication system according to the present embodiment, and different methods may be applied to each cell.

The terminal device 10-1 to the terminal device 10-m are wirelessly connected to any one of the base station device 50-1 to the base station device 50-n, respectively. Further, each of the terminal devices 10-1 to the terminal device 10-m may be wirelessly connected to two or more of the base station devices 50-1 to the base station device 50-n at the same time. E-UTRA or NR can be used for the base station apparatus 50-1 to the base station apparatus 50-n, respectively. For example, the base station apparatus 50-1 may use NR and the base station apparatus 50n may use E-UTRA, and vice versa. The base station device in E-UTRA is called eNB (evolved NodeB), and the base station device in NR is called gNB (g-NodeB).

In the following, when the term "base station device" is used, it means that both eNB and gNB are included. Further, the terminal device in E-UTRA and NR is referred to as UE (User Equipment). The base station device gNB in the NR may be connected to the terminal device by using a part (BWP: Carrier bandwidth part) of the frequency band used by the base station device gNB. Hereinafter, when the term "cell" is used, BWP is included.

Note that FIG. 1 illustrates terminal devices 10-1 to 10-m as terminal devices in the m range (m is an integer of 2 or more). In the following description, when these m-unit terminal devices are described without distinction, a part of the reference numerals is omitted and the term "terminal device 10" is simply referred to. Further, FIG. 1 illustrates base station devices 50-1 to 50-n as n base station devices (n is an integer of 2 or more). In the following description, when these n base station devices are described without distinction, a part of the reference numerals is omitted, and the term "base station device 50" is simply referred to.

Examples of the communication terminal 10 include portable information communication devices such as IoT devices, smartphones, mobile phones, personal digital assistants (PDAs), tablet terminals, portable game machines, portable music players, and wearable terminals. The terminal device 10 may be connected to the base station device 50 in cell units, for example, and may be connected using a plurality of cells, for example, carrier aggregation. When the terminal device 10 is connected via a plurality of base station devices, that is, in the case of dual connectivity, the base station device to be initially connected is the master node (MN: MasterNode), and the base station device to be additionally connected is It is called a secondary node (SN: Secondary Node). The base station devices are connected by a base station interface. Further, the base station device 50 and the core network device 90 are connected by a core interface. The base station interface is used for exchanging control signals necessary for handover and cooperative operation between base station devices.

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

Note that FIG. 1 shows an example in which the core network device 90 is composed of one device, but the present invention is not limited to this. For example, the core network device may include a server, a gateway, and the like, and may be composed of a plurality of devices.

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

Further, the terminal device 10 and the base station device 50 transmit and receive a MAC control element (MAC CE: MAC Control Element) in the medium access control (MAC: Medium Access Control) layer. The RRC message is transmitted as an RRC PDU (Protocol Data Unit), and as the mapped logical channels, a common control channel (CCCH: Common Control Channel), an individual control channel (DCCH: Dedicated Control Channel), and a paging control channel (PCCH:). A Paging Control Channel), a Broadcast Control Channel (BCCH: Broadcast Control Channel), or a multicast control channel (MCCH: Multicast Control Channel) is used. The MAC CE is transmitted as a MAC PDU (or MAC sub PDU). A MAC subPDU is equivalent to a service data unit (SDU: Service Data Unit) in the MAC layer plus, for example, an 8-bit header, and a MAC PDU includes one or more MAC subPDUs.

The physical channels and physical signals related to this embodiment will be described. Among the physical channels according to the embodiment of the present invention, a physical broadcast channel (PBCH: Physical Broadcast Channel), a primary synchronization signal (PSS: Primary Synchronization Signal), a secondary synchronization signal (SSS: Secondary Synchronization Signal), and a physical random access channel (SSS: Secondary Synchronization Signal). The PRACH: Physical Random Access Channel) and the physical downlink control channel (PDCCH: Physical Downlink Control Channel) will be described below. In the wireless communication system according to the embodiment, a physical uplink control channel (PUCCH: Physical Uplink Control Channel), a physical downlink shared channel (PDSCH: Physical Downlink Shared Channel), and a physical uplink shared channel (PUSCH: Physical) are also used. Uplink Shared Channel), scheduling reference signal (SRS: Scheduling Reference Signal), and demodulation reference signal (DMRS: Demodulation Reference Signal) exist at least, but detailed description will be omitted.

<Physical notification 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 a common parameter (system information) in a cell under the base station device 50. System information is further classified into a master information block (MIB: Master Information Block) and a system information block (SIB: System Information Block). The system information block is further subdivided into SIB1, SIB2, ..., And transmitted. The system information includes information necessary for connecting to the cell. For example, the MIB includes information such as a system frame number and information indicating whether or not to camp on the cell. Further, SIB1 contains parameters for calculating cell quality (cell selection parameters), cell-common channel information (random access control information, PUCCH control information, PUSCH control information), scheduling information of other system information, and the like. include. The physical broadcast channel (PBCH) is a synchronization signal block (SSB: Synchronization Signal Block (or SS / PBSH)), which is a set with a synchronization signal composed of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS). Is transmitted periodically. By receiving the synchronization signal block (SSB), the terminal device 10 can measure the signal quality of the cell in addition to acquiring the cell identifier (cell ID) information and the reception timing.

The system information notified by the physical notification channel (PBCH) or the like is also called "system notification information" or "notification information". Further, when camping on a cell, the terminal device 10 completes cell selection and / or cell reselection, and the terminal device 10 selects a cell for monitoring system notification information and paging information. It means to be in a state of being in a state of being. The terminal device 10 establishes the above-mentioned RRC connection with the base station device 50 forming the camp-on cell.

<Primary Sync 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 a signal that the terminal device 10 first attempts to detect in a procedure for detecting a cell of the base station device 50 (hereinafter, also referred to as a “cell search procedure”). As the primary synchronization signal (PSS), three types of signals "0" to "2" are repeatedly used based on the physical cell ID. The physical cell ID is a physical cell identifier, and 504 IDs are used in E-UTRA and 1008 IDs are used in NR.

<Secondary sync 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 for the terminal device 10 to detect the physical cell ID in the cell search procedure. As the secondary synchronization signal (SSS), 168 signals from "0" to "167" are repeatedly used in E-UTRA, and 336 signals from "0" to "335" are repeatedly used in NR based on the physical cell ID. ..

<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 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. Used for resource requests. Information indicating a radio resource capable of transmitting a random access preamble is transmitted to a terminal using broadcast information or an RRC message.

<Physical downlink control channel (PDCCH)>
The physical downlink control channel (PDCCH) is transmitted from the base station apparatus 50 to notify the terminal apparatus 10 of downlink control information (DCI). The downlink control information includes uplink radio resource information (uplink grant (UL grant)) that can be used by the terminal device 10 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 sent 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 a random access preamble. Index information, transmission timing adjustment information, uplink grant, etc. are included.

<Hardware configuration>
The hardware configuration of the terminal device and the base station device according to the embodiment will be described with reference to FIG. FIG. 2 is a configuration diagram showing an example of the hardware configuration of the terminal device 10 and the base station device 50.

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, respectively. Be prepared.

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 includes, for example, 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) and other integrated circuits are included.

The memory 22 and the storage device 23 are each configured to store programs, data, and the like. The memory 22 is composed of, for example, a ROM (ReadOnlyMemory), an EPROM (ErasableProgrammableROM), an EEPROM (ElectricallyErasableProgrammableROM), and / or a RAM (RandomAccessMemory). The storage device 23 is composed of, for example, storage such as an HDD (Hard Disk Drive), an SSD (Solid State Drive) and / or an eMMC (embedded MultiMediaCard).

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, and the like. Further, the communication device 24 may include an amplifier, an RF (Radio Frequency) device that performs processing related to radio signals, and a BB (BaseBand) device that performs baseband signal processing.

The RF device, for example, performs D / A (Digital to Analog) conversion, modulation, frequency conversion, power amplification, etc. on the digital baseband signal received from the BB device to transmit a radio signal transmitted from the antenna 27. Generate. Further, the RF device 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 BB device. The BB apparatus performs a process of converting a digital baseband signal into an IP packet and a process of converting an IP packet into a digital baseband signal.

The input device 25 is configured so that information can be input by a user operation. The input device 25 includes, for example, a keyboard, a touch panel, a mouse, and / or a microphone.

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

The antenna 27 is configured to be able to radiate (radiate) and receive radio waves (electromagnetic waves) in one or a plurality of predetermined frequency bands. The antenna 27 may be a directional antenna. The gain of the directional antenna 27 differs depending on the orientation of the antenna. The antenna 27 may have no directivity, that is, one having omnidirectionality. The omnidirectional antenna 27 has approximately the same gain from all 360 degrees directions in the horizontal plane, in the vertical plane, or both in the horizontal plane and in the non-horizontal plane and in the vertical plane.

The number of antennas 27 is not limited to one. The terminal device 10 and the base station device 50 may include a plurality of antennas. When the terminal device 10 and the base station device 50 include a plurality of antennas, they may be divided into, for example, a transmitting antenna and a receiving antenna. Further, when a plurality of antennas are divided into a transmitting antenna and a receiving antenna, at least one of them may include a plurality of antennas. When the terminal device 10 and the base station device 50 are provided with a plurality of transmission / reception antennas or transmission antennas, a beamforming technique described later can be used.

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

<Functional block configuration>
(Terminal device)
With reference to FIG. 3, a functional block configuration of a terminal device that executes wireless communication with a base station device via a specific frequency band (frequency band) according to one embodiment will be described. FIG. 3 is a configuration diagram showing an example of a functional block configuration of the terminal device 10. Note that FIG. 3 is for showing the functional blocks required in the description of the present embodiment, and does not exclude that the terminal device 10 includes the functional blocks other than those shown in the drawings.

As shown in FIG. 3, the terminal device 10 includes a receiving unit 11, a transmitting unit 13, a measuring unit 15, and a beam control unit 17 as functional blocks.

The receiving unit 11 receives various information from the base station device 50 shown in FIG. For example, the receiving unit 11 receives from the base station device 50 a "UECapacityEncurry" for inquiring about the terminal capability information ("UECapacity Information") of the terminal device 10.

The transmission unit 13 transmits various information to the base station device 50. For example, the transmission unit 13 transmits the terminal capability information of the terminal device 10 to the base station device 50 as a response to the "UECapacityEncurry".

The transmission unit 13 provides, for example, type information regarding a plurality of power class PCs (types) when the beam control unit 17 controls a beam for transmitting a signal from the terminal device 10 to the base station device 50. Send to 50. The type information may be recorded in advance in the storage device 23 of the terminal device 10 shown in FIG. 2, for example. Further, the terminal device 10 may acquire the type information recorded in advance in the external device, for example, the base station device 50 or the core network device 90 shown in FIG.

FIG. 4 is an explanatory diagram illustrating an example of a power class PC in a frequency band (Band n257) in the 28 GHz band (for example, 27.0 GHz to 29.5 GHz). As shown in FIG. 4, a plurality of power class PCs according to the characteristics of the beam for transmitting a signal from the terminal device 10 to the base station device 50 are preset in the "Band n257" (specific frequency band). Has been done. For example, a plurality of power class PCs are preset according to the transmission power of the terminal device 10.

Specifically, as shown in FIG. 4, a plurality of power classes PC1 to PC4 are associated with "Band n257". The type of terminal device is associated with each of the power classes PC1 to PC4. For example, the power class PC1 is a fixed installation type fixed wireless communication terminal, the power class PC2 is an in-vehicle terminal, the power class PC3 is a portable terminal (for example, a smartphone), and the power class PC4 is a high power fixed wireless communication terminal. Alternatively, an in-vehicle terminal is associated with it.

Information on EIRP (Equivalent Iso-tropic Radiated Power) and TRP (Total Radiated Power) is associated with each of the power classes PC1 to PC4, for example. Here, EIRP is equivalent isotropic radiated power in the beam direction, and includes transmission power at a predetermined point on the radio wave radiation space. The TRP includes a total radiated power that defines the total power radiated from the terminal device 10. Further, "Min. Peak EIRP" includes a value (minimum peak value) that at least one of the measured EIRPs should satisfy at a minimum. "Max EIRP" includes a value (EIRP maximum permissible value) that is not allowed to exceed the maximum value of EIRP among the measured EIRPs. "EIRP Physical coverage" includes a value to be guaranteed by the (100-X)% area on the radio spherical space with respect to the measured EIRP. "Max TRP" includes a value (TRP maximum permissible value) that is not allowed to exceed the maximum value of EIRP among the TRPs to be measured.

In the power class PC1, since "Max TRP" is defined as "35 dBm" which is larger than other power classes, relatively strong power radiation is allowed. Further, in the power class PC1, since high "Min. Peak EIRP" and "Sphere cover" are specified, the formation of a relatively sensitive beam is permitted. The power class PC2 has the same power radiation characteristics as the power class PC3, but "Min. Peak EIRP" and "Sphere coverage" are higher than the power class PC3, and the formation of a sharper beam is allowed. As described above, the power class PC3 is assumed to be a type of smartphone that moves frequently, so "Sphere cover" is defined as a relatively wide range of "50%". In the power class PC5, "Spherical cover" is defined as "20%" in a wider range, and "Min. Peak EIRP" is defined as "34 dBm", so that a wide range and strong power radiation is allowed.

In the above, an example of a plurality of power class PCs associated with "Band n257" has been described, but a plurality of power class PCs are provided for each of the other plurality of bands, for example, "Band n258" and "Band n261". It may be associated. Further, a plurality of power classes may be associated with each of a plurality of bands in a frequency band other than the 28 GHz band (millimeter wave band).

The measuring unit 15 measures the status of the terminal device 10. For example, the measuring unit 15 measures the antenna characteristics (for example, transmission power or reception sensitivity) of the terminal device 10. The measuring unit 15 determines the antenna identification by measuring at least one of the communication status in the wireless communication between the terminal device 10 and the base station device 50 or the movement status of the terminal device 10.

As a communication status measuring unit, for example, the measuring unit 15 measures the reception status of the signal transmitted by the base station device 50 using the beam at one or more antennas 27 of the terminal device 10. The measuring unit 15 measures the signal reception status based on a predetermined physical quantity, for example, the level of the received signal level (reception intensity). Specifically, at least one of RSRP (Reference Signal Received Power) and RSSI (Received Signal Strength Indicator) is referred to as the received signal level.

RSRP is a basic parameter for evaluating the received signal level of radio waves from the base station device 50. RSRP is measured based on the beamforming situation of the base station apparatus 50. Further, the RSRP determines the installation conditions of the base station device 50 including the transmission power of the base station device 50, the direction and height of the antenna of the base station device 50, the distance from the base station device 50, the presence or absence of obstacles, and the like. Determined based on the measurement environment involved. Like RSRP, RSSI is a basic parameter for evaluating the received signal level of radio waves from the base station apparatus 50. However, unlike RSRP, RSSI is a parameter that can change not only depending on the installation conditions and measurement environment of the base station apparatus 50, but also on the traffic volume of the base station to be measured and the peripheral base stations.

Even if the measuring unit 15 further refers to at least one of RSRQ (Reference Signal Received Quality) and SINR (Signal to Interference plus Noise power Ratio) as a physical quantity for determining the reception status, and determines the signal reception status. good.

RSRQ is one of the indexes showing the reception quality of radio waves from the base station device 50, and is a parameter calculated by the ratio of RSRP and RSSI. SINR is a parameter indicating the received signal power to interference and noise power ratio in consideration of interference from surrounding base station devices and other relay devices.

In addition to the above measurement results, the measuring unit 15 may further measure PHR (Power Headroom), that is, information on the remaining transmission power of the terminal device 10 as information on the transmission power of the terminal device 10. Further, the measuring unit 15 may measure EIS (Equivalent Iso-tropic Sensitivity), which is the received power (equivalent isotropic sensitivity) at a predetermined point on the radio wave receiving space.

The measurement unit 15 measures the movement status of the terminal device 10, for example, as a movement status measurement unit. For example, the measuring unit 15 acquires the detection information of the sensor 29 (for example, the GPS sensor) shown in FIG. 2, measures the moving state of the terminal device 10, and outputs it as the moving state information. The movement status information may be information indicating the presence / absence (binary value) of movement of the terminal device 10. The movement status information may include, for example, the movement speed information of the terminal device 10 and may be information such as the actual movement speed (m / s) of the terminal device 10, or the movement speed of the terminal device 10 may be "high speed". , "Medium speed", "Low speed", etc. may be information indicated by three or more values.

The beam control unit 17 forms or controls a beam for transmitting a signal from the terminal device 10 to the base station device 50. The beam control executed by the beam control unit 17 will be specifically described. In NR and E-UTRA, the terminal device 10 employs beamforming in order to secure the communicable distance and area between the terminal device 10 and the base station device 50. Beamforming is a technique for forming a directional pattern or a directional beam by controlling the amplitude and phase of each of a plurality of antennas 27 to increase or decrease the gain of the antenna in a specific direction. By applying beamforming, it is possible to concentrate the signal strength of the transmission signal (transmission beam) in a specific direction and extend the communication distance. On the other hand, since the signal strength decreases in directions other than the specific direction, the reachable range of the transmitted signal becomes narrow. Therefore, NR supports beam sweeping in which the directions of transmission signals are sequentially switched and a plurality of transmission signals (transmission beams) are transmitted. The base station device 2 is not limited in the number of directions in which the beam is switched, but for example, the base station device 2 switches in eight directions to transmit a transmission signal. Although the beamforming technique in the terminal device 10 has been described above, the technique may be similarly adopted in the base station device 50 as well.

The beam control unit 17 controls the beam according to the situation of the terminal device 10. The beam control unit 17 changes, for example, a beam formed based on a specific power class PC among a plurality of power class PCs 1 to PC4 from a specific power class PC to another power class PC among the plurality of power class PCs 1 to PC4. Control. For example, the beam control unit 17 may control the beam by changing a specific power class PC to another power class PC based on the measurement result of the measurement unit 15.

FIG. 5 is an explanatory diagram illustrating an example of beam control processing performed by the terminal device according to the embodiment. As shown in FIG. 5, for example, when the terminal device 10 is located at the point P1 in the cell C of the base station device 50, the power class PC2 is adopted and the radio wave transmission range is relatively narrow, but comparison is made. It forms a beam that can transmit radio waves far away. After that, when the terminal device 10 moves at a high speed at a point P3 farther from the base station device 50 than the point P1, the power class PC 3 is adopted based on the measurement result regarding the situation of the terminal device 10. Then, the terminal device 10 forms a beam in which the radio wave transmission distance is short and the radio wave transmission range is relatively wide as compared with the case where the power class PC2 is adopted. In this way, the beam control unit 17 controls the beam by switching to the optimum power class according to the situation of the terminal device 10.

The receiving unit 11 and the transmitting unit 13 may be realized by, for example, the communication device 24, or may be realized by the processor 21 executing the program stored in the storage device 23 in addition to the communication device 24. .. The measuring unit 15 and the beam control unit 17 may be realized by the processor 21 executing a program stored in the storage device 23. When executing a program, the program may be stored in a storage medium. The storage medium in which the program is stored may be a computer-readable non-transitory storage medium (Non-transitory computer readable medium). The non-temporary storage medium is not particularly limited, but may be, for example, a storage medium such as a USB (Universal Serial Bus) memory or a CD-ROM (Compact Disc ROM).

(Base station equipment)
With reference to FIG. 6, a functional block configuration of a base station device that executes wireless communication with a terminal device via a specific frequency band according to one embodiment will be described. FIG. 6 is a configuration diagram showing an example of a functional block configuration of the base station device 50. Note that FIG. 6 is for showing the functional blocks required in the description of the present embodiment, and does not exclude that the base station apparatus 50 includes functional blocks other than those shown in the drawings.

As shown in FIG. 6, the base station apparatus 50 includes a receiving unit 51, a transmitting unit 53, and a beam control unit 55 as functional blocks.

The receiving unit 51 receives type information related to a plurality of power class PCs from the terminal device 10. The transmission unit 53 controls the beam formed based on a specific power class PC among the plurality of power class PCs in the terminal device 10 by changing the specific power class PC to another power class PC among the plurality of power class PCs. A request to be made is transmitted to the terminal device 10.

The beam control unit 55 forms or controls a beam for transmitting a signal from the base station device 50 to the terminal device 10. The beam control unit 55 searches for the beam formed or controlled in the terminal device 10 and adapts the beam in the base station device 50 to the beam formed or controlled in the terminal device 10.

The receiving unit 51 and the transmitting unit 53 may be realized by, for example, the communication device 24, or may be realized by the processor 21 executing the program stored in the storage device 23 in addition to the communication device 24. .. The beam control unit 55 may be realized by the processor 21 executing a program stored in the storage device 23. When executing a program, the program may be stored in a storage medium. The storage medium in which the program is stored may be a non-temporary storage medium that can be read by a computer. The non-temporary storage medium is not particularly limited, but may be, for example, a storage medium such as a USB memory or a CD-ROM.

<Beam control processing>
(Embodiment 1)
FIG. 7 is a flowchart showing an example of the beam control process according to the first embodiment of the present invention. As a premise, 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).

As shown in FIG. 7, the base station apparatus 50 transmits “UECapacityEncurry” to the terminal apparatus 10 (step S1). The terminal device 10 transmits "UECapacity Information" to the base station device 50 as a response to the "UECapacityEnquiry" (step S3). For example, the "UE Capacity Information" includes type information regarding a plurality of power class PCs associated with each frequency band as shown in FIG. As shown in FIG. 4, the type information may include information (UE-PowerClass) in which parameters of a plurality of power classes PC1 to PC5 are listed for each frequency band. The type information may be transmitted to the base station apparatus 50 in a new format as "additional UE-powerClass capability".

The terminal device 10 measures the status of the terminal device 10 (step S5). The terminal device 10 notifies the base station device 50 that the power class PC is switched in order to control the beam in the terminal device 10 based on the measurement result (step S7). The base station device 50 responds to the notification from the terminal device 10 (step S9). The terminal device 10 controls the beam in the terminal device 10 (step S11). After that, the terminal device 10 may notify the base station device 50 that the beam in the terminal device 10 has been controlled. The beam search in the base station apparatus 50 or the beam control in the base station apparatus 50 is performed before or after the base station apparatus 50 receives the notification indicating that the beam in the terminal apparatus 10 has been controlled. It may be executed.

After the beam control process in step S11, the status of the terminal device 10 may be measured again (step S13). Then, the terminal device 10 may notify the base station device 50 that the power class PC is switched in order to control the beam in the terminal device 10 based on the measurement result (step S15). In this way, the terminal device 10 can measure the current state of its own device periodically or at an arbitrary timing, and appropriately control the beam based on the measurement result.

As described above, according to the first embodiment, a plurality of types according to the characteristics of the beam for transmitting a signal from the terminal device 10 to the base station device 50 are preset in the specific frequency band. When the terminal device 10 controls a beam formed based on a specific type among a plurality of types by changing the specific type to another type among the plurality of types, the type information regarding the plurality of types is used. Is transmitted to the base station device 50. Therefore, since the base station apparatus 50 can acquire the type information in advance, the base station apparatus 50 appropriately executes the beam search and the like. Therefore, since the communication connection between the terminal device 10 and the base station device 50 is appropriately executed, the stability in wireless communication is maintained.

(Embodiment 2)
In the second embodiment, the terminal device 10 voluntarily controls the beam in the terminal device 10 by changing the specific type to another type based on the request from the base station device 50. It is different from the first embodiment in which the beam is controlled. Hereinafter, the points different from the first embodiment will be particularly described.

FIG. 8 is a flowchart showing an example of the beam control process according to the second embodiment of the present invention. Since steps S21, S23 and S25 in FIG. 8 are the same processes as steps S1, S3 and S5 in FIG. 7, description thereof will be omitted.

As shown in FIG. 8, the terminal device 10 notifies the base station device 50 of the measurement result (step S7). The base station device 50 requests the terminal device 10 to switch the power class PC in order to control the beam in the terminal device 10 (step S29). The terminal device 10 controls the beam in the terminal device 10 based on the request from the base station device 50 (step S31). The terminal device 10 notifies the base station device 50 that the beam in the terminal device 10 has been controlled (step S33). The beam search in the base station apparatus 50 or the beam control in the base station apparatus 50 is performed before or after the base station apparatus 50 receives the notification indicating that the beam in the terminal apparatus 10 has been controlled. It may be executed.

After the beam control process in step S31, the status of the terminal device 10 may be measured again (step S35). Then, the terminal device 10 may notify the base station device 50 of the measurement result (step S37). In this way, the terminal device 10 measures the current state of its own device periodically or at an arbitrary timing, notifies the base station device 50 of the measurement result, and the base station device 50 uses the terminal. The device 10 may be required to control the beam in the terminal device 10.

As described above, according to the second embodiment, in addition to the effect of the first embodiment, the terminal device 10 changes the specific type to another type based on the request from the base station device 50, so that the beam in the terminal device 10 is used. Can be controlled.

Each of the above embodiments is for facilitating the understanding of the present invention, and does not limit the interpretation of the present invention. The present invention can be modified / improved without departing from the spirit of the present invention, and the present invention also includes an equivalent thereof.

10 (10-1 ... 10-m) ... Terminal device, 11,51 ... Receiver unit, 13,53 ... Transmitter unit, 15 ... Measurement unit, 17,55 ... Beam control unit, 21 ... Processor, 22 ... Memory, 23 ... storage device, 24 ... communication device, 25 ... input device, 26 ... output device, 27 ... antenna, 29 ... sensor, 50 (50-1 ... 50-n) ... base station device, 90 ... core network device, 100 ... Wireless communication system

Claims (8)

A terminal device that performs wireless communication with a base station device via a specific frequency band.
In the specific frequency band, a plurality of types according to the characteristics of the beam for transmitting a signal from the terminal device to the base station device are preset.
A beam control unit that controls the beam formed based on a specific type among the plurality of types by changing the specific type to another type among the plurality of types.
A transmission unit that transmits type information regarding the plurality of types to the base station apparatus when controlling the beam is provided.
Terminal equipment. Further, a measuring unit for measuring at least one of the communication status in the wireless communication or the movement status of the terminal device based on the position information of the terminal device is provided.
The beam control unit controls the beam by changing the specific type to the other type based on the measurement result of the measurement unit.
The terminal device according to claim 1. The beam control unit controls the beam by changing the specific type to the other type based on a request from the base station apparatus.
The terminal device according to claim 1 or 2. The plurality of types are preset according to the transmission power of the terminal device.
The terminal device according to any one of claims 1 to 3. The plurality of types are set according to at least one of the equivalent isotropic radiant power in the direction of the beam or the total radiated power indicating the total power radiated from the terminal device.
The terminal device according to claim 4. A wireless communication method used for a terminal device that performs wireless communication with a base station device via a specific frequency band.
In the specific frequency band, a plurality of types according to the characteristics of the beam for transmitting a signal from the terminal device to the base station device are preset.
A step of controlling the beam formed based on a specific type among the plurality of types by changing the specific type to another type among the plurality of types.
A step of transmitting type information regarding the plurality of types to the base station apparatus when controlling the beam is included.
Wireless communication method. A base station device that performs wireless communication with a terminal device via a specific frequency band.
In the specific frequency band, a plurality of types according to the characteristics of the beam for transmitting a signal from the terminal device to the base station device are preset.
A receiving unit that receives type information related to the plurality of types from the terminal device, and
A request for controlling the beam formed in the terminal device based on a specific type among the plurality of types by changing the specific type to another type among the plurality of types. A transmission unit that transmits to the terminal device is provided.
Base station equipment. A wireless communication method used for a base station device that performs wireless communication with a terminal device via a specific frequency band.
In the specific frequency band, a plurality of types according to the characteristics of the beam for transmitting a signal from the terminal device to the base station device are preset.
A step of receiving type information regarding the plurality of types from the terminal device, and
A request for controlling the beam formed in the terminal device based on a specific type among the plurality of types by changing the specific type to another type among the plurality of types. Including a step of transmitting to the terminal device.
Wireless communication method.

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