Network server and terminal device

Abstract

A network server comprises: an acquisition unit that acquires, from each of a plurality of terminal devices held by the same subject at mutually different positions, radio information including radio quality information for each beam obtained between a base station capable of using a plurality of beams having directivity in different directions and each of the plurality of terminal devices, and information indicating the positions at which the plurality of terminal devices are respectively held; and a state estimation unit that estimates the state of the subject or the plurality of terminal devices on the basis of the radio information acquired by the acquisition unit.　

Description

Network Server and Terminal Device

[0001] The present invention relates to a network server and a terminal device.

[0002] In recent years, the use of millimeter waves has been widely studied to increase the speed and capacity of wireless communications. However, millimeter waves have a high degree of directivity and are subject to significant attenuation due to factors such as moisture in the atmosphere. Therefore, compared to lower frequency bands such as Sub-6 (less than 6 GHz), degradation in quality due to self-shielding by structures and human bodies, fading, or imperfect beam tracking caused by terminal rotation, etc., is a serious issue. To address this issue, terminal cooperation techniques have been proposed that improve the stability of millimeter wave communications by cooperative operation among multiple terminal devices. One form of terminal cooperation is a technology that adaptively selects a terminal device with better wireless quality from a group of multiple terminal devices and operates it as a repeater, thereby stabilizing quality.

[0003] In millimeter waves, wireless quality fluctuates significantly, and these fluctuations depend heavily on the state of the terminal device, making it important to estimate the state of the terminal device. Conventionally, in an environment where base stations are distributed and radio wave reflectors are installed, techniques for estimating user location information using radio waves arriving from a single terminal device and multiple base stations (e.g., reflectors) have been proposed (see Non-Patent Documents 1 and 2).

[0004] Z. Chen, et al., “Joint Location Sensing and Channel Estimation for IRS-Aided mmWave ISAC Systems”, IEEE Transactions on Wireless communications, 2023. P. Picazo, et al., “waveSLAM Empowering Accurate Indoor Mapping Using Off-the-Shelf Millimeter-wave Self-sensing”, in Proc. of 2023 IEEE VTC-Fall, 2023.

[0005] However, conventional techniques have had the problem that the accuracy of state estimation decreases when communication with multiple base stations is not possible or in an environment where radio wave reflectors are not installed.

[0006] In view of the above circumstances, an object of the present invention is to provide a technology that can perform state estimation with high accuracy.

[0007] One aspect of the present invention is a network server comprising: a base station capable of utilizing multiple beams having directivities in different directions; an acquisition unit that acquires, from each of multiple terminal devices, radio information including radio quality information for each beam obtained between the same object and each of multiple terminal devices held at different positions from each other, and information indicating the holding position of each of the multiple terminal devices; and a state estimation unit that performs state estimation of the object or the multiple terminal devices based on the radio information acquired by the acquisition unit.

[0008] One aspect of the present invention is a terminal device that operates as a master terminal among multiple terminal devices belonging to the same group, and that includes: a base station that can use multiple beams having directivities in different directions; an acquisition unit that acquires radio information from each of the other terminal devices, including radio quality information for each beam obtained between each of multiple terminal devices other than the terminal device itself and the other terminal devices held by the same object at different positions, and information indicating the holding positions of each of the other terminal devices; and a state estimation unit that performs state estimation of the object or the other terminal devices based on the radio information acquired by the acquisition unit.

[0009] According to the present invention, it is possible to perform state estimation with high accuracy.

[0010] FIG. 1 is a diagram illustrating an example of the configuration of a wireless communication system in a first embodiment. FIG. 2 is a diagram illustrating an example of the configuration of a terminal device in the first embodiment. FIG. 3 is a diagram illustrating an example of the configuration of a network server in the first embodiment. FIG. 4 is a sequence diagram illustrating the flow of processing in a wireless communication system in the first embodiment. FIG. 5 is a diagram illustrating a state estimation method in the first embodiment. FIG. 6 is a diagram illustrating the state estimation method in the first embodiment. FIG. 7 is a diagram illustrating the state estimation method in the first embodiment. FIG. 8 is a diagram illustrating a configuration example of a wireless communication system in a second embodiment. FIG. 9 is a diagram illustrating an example of the configuration of a terminal device in the second embodiment. FIG. 10 is a sequence diagram illustrating the flow of processing in a wireless communication system in the second embodiment.

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0012] (First embodiment) Fig. 1 is a diagram showing an example of the configuration of a wireless communication system 100 according to the first embodiment. The wireless communication system 100 includes a base station 10, a plurality of terminal devices 20, and a network server 30. Fig. 1 shows a case in which the wireless communication system 100 includes three terminal devices 20-1 to 20-3, but the number of terminal devices 20 may be any number as long as there is more than one. Furthermore, the number of base stations 10 and the number of network servers 30 may also be multiple. The base station 10 and each terminal device 20 are connected wirelessly, and the base station 10 and the network server 30 are connected wirelessly or by wire.

[0013] The base station 10 is a base station in a RAN (Radio Access Network). The base station 10 communicates with a plurality of terminal devices 20 and with a network server 30. For example, in response to a connection request transmitted from a plurality of terminal devices 20, the base station 10 transmits a reference signal to the terminal device 20 that is the source of the connection request. The connection request is a signal transmitted from the terminal device 20 to the base station 10 to request a connection. The reference signal is, for example, a sounding signal.

[0014] The base station 10 forms beams having directivities in different directions in communication with each terminal device 20. For example, the base station 10 forms beams including beam IDs corresponding to the respective beams using sequences orthogonal to each other, and transmits reference signals, etc. The base station 10 assigns beams to each terminal device 20 based on feedback information fed back from each terminal device 20, and notifies each terminal device 20 of the beam ID.

[0015] The feedback information includes at least identification information for identifying the terminal device 20 (hereinafter referred to as "terminal identification information") and information indicating the received power value for each beam ID. The base station 10 can identify the optimal beam for each terminal device 20 based on the terminal identification information included in the feedback information received from each terminal device 20 and the information indicating the received power value for each beam ID. For example, the base station 10 determines the beam corresponding to the beam ID with the largest received power value as the optimal beam. The base station 10 then notifies each terminal device 20 of the beam ID indicating the identified optimal beam for each terminal device 20. This determines the optimal beam to be used for communication between the base station 10 and each terminal device 20.

[0016] Furthermore, the base station 10 transfers the information transmitted from each of the plurality of terminal devices 20 to the network server 30 .

[0017] The terminal device 20 is a terminal that communicates in a frequency band of millimeter waves or higher. The terminal device 20 is a terminal that is powered by power supplied from a battery that the terminal device itself has. The terminal device 20 forms a group with one or more other terminal devices 20. The terminal devices 20 that belong to each group form wireless or wired PAN (Personal Area Network) links between the terminal devices 20 that belong to the same group, thereby forming a PAN network.

[0018] A PAN is a network made up of terminals located in close proximity, and is a network that uses less power than a RAN. Figure 1 shows an example in which there is one group G1 in a wireless communication system 100, and three terminal devices 20-1 to 20-3 exist in the group G1. Note that although Figure 1 shows one group, there may be multiple groups in the wireless communication system 100.

[0019] All of the multiple terminal devices 20 belonging to the same group are held by the same user. For example, multiple terminal devices 20 belonging to the same group are held around the body of the same user. Holding around the user's body does not necessarily mean that the terminal devices 20 are attached to the user's body, but may mean that the user holds all of the multiple terminal devices 20, such as that the terminal devices 20 are attached to clothing worn by the user or that the terminal devices 20 are in a pocket of the user's clothing.

[0020] The user is not limited to a person, but may be, for example, an autonomous sensing robot, etc. When the user is an autonomous sensing robot, holding the terminal devices around the user's body does not necessarily mean being attached to the autonomous sensing robot, but may mean being inside the autonomous sensing robot, as long as the autonomous sensing robot holds all of the multiple terminal devices 20.

[0021] Holding positions are registered in advance in the multiple terminal devices 20. The holding positions are information indicating a relative position with respect to the user, such as the user's right arm, left arm, or inside the right pocket. The multiple terminal devices 20 each form an independent wireless communication link with the base station 10. The multiple terminal devices 20 can acquire wireless information such as wireless quality information and wireless connection information between the base station 10 and the terminal devices 20 by using each reference signal transmitted from the base station 10 using a different beam.

[0022] The wireless quality information is information about the quality of wireless communication, such as received power (e.g., RSSI (Received Signal Strength Indicator) and RSRP (Reference Signal Received Power)), channel quality indicator (CQI), SINR (Signal to Interference Noise Ratio), throughput, communication success rate, physical layer information, etc. The wireless connection information is information about the wireless connection with the base station 10, such as the ID and frequency band of the assigned beam. The multiple terminal devices 20 transmit the acquired wireless information to the network server 30 via the base station 10.

[0023] The network server 30 is a server installed in a network (e.g., a core network) higher than the base station 10. The network server 30 estimates the state of the user using wireless information transmitted from each terminal device 20 and location information of the base station 10. The state of the user is, for example, the user's position and posture, the positional relationship with the base station 10, or the shielding state of each terminal device 20.

[0024] (Configuration of Terminal Device 20) Next, the configuration of the terminal device 20 will be described using Fig. 2. Fig. 2 is a diagram showing an example of the configuration of the terminal device 20 in the first embodiment. The terminal device 20 includes a RAN communication unit 21, a PAN communication unit 22, a reception processing unit 23, a control unit 24, and a group terminal information storage unit 25.

[0025] The RAN communication unit 21 is a wireless interface for the RAN. The RAN communication unit 21 communicates with the base station 10. For example, the RAN communication unit 21 transmits a connection request to the base station 10 and receives a reference signal transmitted from the base station 10.

[0026] The PAN communication unit 22 is a wireless interface for the PAN, and communicates with the terminal devices 20 in the group.

[0027] The reception processing unit 23 demodulates the received signal by performing digital signal processing on the signal received by the RAN communication unit 21 or the PAN communication unit 22 .

[0028] The control unit 24 controls the entire terminal device 20. The control unit 24 is configured using one or more processors such as a CPU (Central Processing Unit) and one or more memories. The control unit 24 realizes the functions of a connection request unit 241, a wireless information acquisition unit 242, and an information notification unit 243 by the one or more processors executing programs.

[0029] The connection request unit 241 transmits a connection request to the base station 10 to request a connection to the base station 10 .

[0030] The radio information acquisition unit 242 acquires radio information based on a signal (e.g., a reference signal) obtained through radio communication with the base station 10. The radio information acquisition unit 242 acquires radio quality information based on, for example, a reference signal (e.g., a sounding signal) transmitted from the base station 10 in response to a connection request. The radio information acquisition unit 242 transmits, to the base station 10, feedback information in which terminal identification information is associated with a received power value for each beam ID based on the acquired radio quality information. Note that, when the terminal device 20 selects a beam with the highest received power, the radio information acquisition unit 242 may transmit, to the base station 10, feedback information in which the beam ID corresponding to the beam with the highest received power is associated with the terminal identification information.

[0031] Furthermore, the wireless information acquisition unit 242 acquires wireless connection information based on a beam notification transmitted from the base station 10. The beam notification is a signal for notifying the base station 10 of the beam to be used for wireless communication with the terminal device 20, and includes information such as a beam ID and frequency band assigned to the terminal device 20, for example.

[0032] The information notification unit 243 notifies other devices of terminal information including the wireless information acquired by the wireless information acquisition unit 242 and information indicating the holding location registered in the terminal device 20. The information notification unit 243 notifies, for example, the network server 30 of the terminal information. Note that the information notification unit 243 may notify the terminal information by including information on the reception power of each received beam in the terminal information.

[0033] Identification information for identifying each terminal device 20 belonging to the same group is stored in the group terminal information storage unit 25. The group terminal information storage unit 25 is configured using a storage device such as a magnetic storage device or a semiconductor storage device.

[0034] (Configuration of Network Server 30) Next, the configuration of the network server 30 will be described with reference to Fig. 3. Fig. 3 is a diagram showing an example of the configuration of the network server 30 in the first embodiment. The network server 30 includes a communication unit 31, a storage unit 32, and a control unit 33.

[0035] The communication unit 31 is a communication interface. The communication unit 31 communicates with the base station 10 via communication or wired. The communication unit 31 receives, for example, terminal information transmitted from each terminal device 20 via the base station 10.

[0036] The storage unit 32 is configured using a storage device such as a magnetic storage device or a semiconductor storage device. The storage unit 32 stores terminal storage location information 321, radio information 322, and base station information 323. The terminal storage location information 321 is information indicating the storage location of each terminal device 20. The terminal storage location information 321 is associated with identification information of the terminal device 20. Note that if there are multiple groups in the wireless communication system 100, the storage unit 32 may store the terminal storage location information 321 for each group.

[0037] The wireless information 322 is wireless information of each terminal device 20. The wireless information 322 is associated with identification information of the terminal device 20. If multiple groups exist in the wireless communication system 100, the wireless information 322 may be stored in the storage unit 32 for each group.

[0038] The base station information 323 is information related to the base station 10. The base station information 323 includes, for example, information indicating the installation location of the base station 10 and information indicating the direction (angle) of each beam transmitted by the base station 10. The information indicating the direction (angle) of each beam transmitted by the base station 10 is, for example, information in which the beam direction (angle) is associated with each beam ID corresponding to each beam.

[0039] The control unit 33 controls the entire network server 30. The control unit 33 is configured using one or more processors such as a CPU and one or more memories. The control unit 33 realizes the functions of the acquisition unit 331 and the state estimation unit 332 by the one or more processors executing programs.

[0040] The acquisition unit 331 acquires various types of information. For example, the acquisition unit 331 acquires wireless information transmitted from each terminal device 20. For example, the acquisition unit 331 acquires information about the base station 10. The acquisition unit 331 may acquire the information about the base station 10 by any method. For example, the acquisition unit 331 may acquire the information about the base station 10 from the base station 10, or may acquire the information about the base station 10 by a user registering with the network server 30, or may acquire the information about the base station 10 from an external device.

[0041] The state estimation unit 332 estimates a state based on the information stored in the storage unit 32. The state estimation unit 332 estimates a state such as the user's position, the user's orientation, the user's moving direction, the positional relationship between the user and the base station 10, or the shielding state of each terminal device 20, for example.

[0042] (Operation of wireless communication system 100) Next, the operation of the wireless communication system 100 in the first embodiment will be described with reference to Fig. 4. Fig. 4 is a sequence diagram showing the processing flow of the wireless communication system 100 in the first embodiment. In the description of Fig. 4, three terminal devices 20 will be used as an example, and the three terminal devices 20 will be referred to as a terminal device group in Fig. 4. In the description of Fig. 4, branch numbers will be used to distinguish the functional units of each terminal device 20. For example, the functional unit of terminal device 20-1 will be described with a branch number "-1".

[0043] Each of the terminal devices 20-1 to 20-3 registers the holding position of the terminal device 20-1 to 20-3 in response to a user operation (step S101). For example, the terminal device 20-1 registers information indicating the user's right arm as the holding position of the terminal device 20-1 in response to a user operation, the terminal device 20-2 registers information indicating the user's left arm as the holding position of the terminal device 20-2 in response to a user operation, and the terminal device 20-3 registers information indicating the inside of the user's right pocket as the holding position of the terminal device 20-3 in response to a user operation.

[0044] After the information on the holding location is registered, each of the terminal devices 20-1 to 20-3 makes a connection request to the base station 10. For convenience of explanation, a case will be described here in which each of the terminal devices 20-1 to 20-3 makes a connection request to the base station 10 at different times, but any of the terminal devices 20-1 to 20-3 may make a connection request to the base station 10 at the same time.

[0045] The connection request unit 241-1 of the terminal device 20-1 transmits a connection request to the base station 10 (step S102). The base station 10 receives the connection request transmitted from the terminal device 20-1. The base station 10 transmits a reference signal to the terminal device 20-1 in response to the received connection request (step S103). At this time, the base station 10 transmits the reference signal by switching between multiple beams over time. The RAN communication unit 21-1 of the terminal device 20-1 receives the reference signal transmitted from the base station 10.

[0046] The radio information acquisition unit 242-1 of the terminal device 20-1 measures the received power based on the received reference signal (step S104). The radio information acquisition unit 242-1 performs this process for each beam formed by the base station 10. This allows the radio information acquisition unit 242-1 to acquire information on the received power for each beam formed by the base station 10. The radio information acquisition unit 242-1 transmits feedback information, which associates the terminal identification information with the acquired information on the received power for each beam ID, to the base station 10 via the RAN communication unit 21-1 (step S105).

[0047] The base station 10 receives the feedback information transmitted from the terminal device 20-1. The base station 10 assigns a beam to the terminal device 20-1 based on the received feedback information (step S106). For example, the base station 10 assigns to the terminal device 20-1 a beam corresponding to the beam ID with the maximum received power among the received powers for each beam ID included in the feedback information. The base station 10 transmits to the terminal device 20-1 a beam notification including the beam ID corresponding to the beam assigned to the terminal device 20-1 and information indicating the frequency band (step S107).

[0048] The RAN communication unit 21-1 of the terminal device 20-1 receives the beam notification transmitted from the base station 10. The radio information acquisition unit 242-1 of the terminal device 20-1 acquires the received beam notification. The radio information acquisition unit 242-1 outputs terminal information to the information notification unit 243-1, the terminal information including information indicating the beam ID and frequency band contained in the acquired beam notification, information indicating the reception power of the beam corresponding to the beam ID, and information indicating the holding position registered in the terminal device 20-1. The information notification unit 243-1 transmits the terminal information output from the radio information acquisition unit 242-1 to the base station 10 via the RAN communication unit 21-1 (step S108).

[0049] The processes from step S102 to step S108 described above are also performed for terminal device 20-2 and terminal device 20-3. As a result, the base station 10 receives the terminal information transmitted from each of terminal devices 20-1 to 20-3. The base station 10 transfers the received terminal information for each of terminal devices 20-1 to 20-3 to the network server 30 (step S109).

[0050] The communication unit 31 of the network server 30 receives the terminal information of each of the terminal devices 20-1 to 20-3 transferred from the base station 10. Note that, for the sake of simplicity, an example is shown in which the terminal information of each of the terminal devices 20-1 to 20-3 is transferred from the base station 10 to the network server 30 all at once, but the base station 10 may transfer the terminal information to the network server 30 at the timing of acquiring it.

[0051] The acquisition unit 331 acquires the terminal information of each of the terminal devices 20-1 to 20-3 received by the communication unit 31. The acquisition unit 331 stores the acquired terminal information of each of the terminal devices 20-1 to 20-3 in the storage unit 32. For example, the acquisition unit 331 associates information indicating a holding position included in the terminal information with identification information of the terminal device 20 and stores it as terminal holding position information 321. For example, the acquisition unit 331 associates information indicating a beam ID, a frequency band, and information indicating reception power included in the terminal information with identification information of the terminal device 20 and stores it as radio information 322.

[0052] The state estimation unit 332 performs state estimation using the information stored in the storage unit 32 (step S110). A number of state estimation methods will be described below.

[0053] (State Estimation Method 1) As state estimation method 1, a method for estimating a user's position, orientation, and movement direction will be described using FIG. 5. FIG. 5 is a diagram for explaining the state estimation method in the first embodiment. The example shown in FIG. 5 shows a case where a user U holds a terminal device 20-1 on his right arm and a terminal device 20-2 on his left arm. In this description, it is assumed that the base station 10 is capable of emitting five beams #1 to #5 with different emission angles in the horizontal direction. It is also assumed that the network server 30 holds base station information.

[0054] When user U is moving in the direction of the arrow (from the bottom to the top of FIG. 5), as viewed from the base station 10, terminal device 20-1 is in line of sight, and terminal device 20-2 is blocked by user U. The terminal devices 20-1 and 20-2 can receive beam #3 as a direct beam from the base station 10. The received power of beam #3 at terminal device 20-1 and terminal device 20-2 is respectively R ３ （１） , R ３ （２） When the user U is blocked, the received power is attenuated. ３ （１） >R ３ （２） This becomes:

[0055] On the other hand, when there are reflecting objects such as walls, such as indoors, the terminal device 20-2 can receive beams other than beam #3. In the example shown in Fig. 5, for example, the terminal device 20-2 can receive beam #2 as a reflected wave. Since both the terminal device 20-1 and the terminal device 20-2 can receive beam #3, the state estimation unit 332 of the network server 30 estimates that the user U is located in the direction (angle) of beam #3 as seen from the base station 10. Furthermore, the state estimation unit 332 estimates the direction of the user U based on the holding positions of the terminal device 20-1 and the terminal device 20-2 (for example, information indicating the right arm and the left arm), the received power of each beam, and the beam ID corresponding to the received beam.

[0056] For example, the network server 30 acquires, as terminal information, from the terminal device 20-1 held on the right arm of the user U, information indicating that the terminal device is held on the right arm, a beam ID corresponding to the received beam #3, and information indicating the received power of beam #3. Furthermore, for example, the network server 30 acquires, as terminal information, from the terminal device 20-2 held on the left arm of the user U, information indicating that the terminal device is held on the left arm, a beam ID corresponding to each of the received beams #2 and #3, and information indicating the received power of each of beams #2 and #3. As a result, the state estimation unit 332 estimates that the user U is facing in a direction in which the terminal device 20-1 held on the right arm can receive beam #2 and the terminal device 20-2 held on the left arm can receive beams #2 and #3. For example, the state estimation unit 332 estimates that the user U is facing in the direction of the arrow.

[0057] Furthermore, the state estimation unit 332 estimates the position and moving direction of the user U based on the beam angle, the position information of the base station 10, and the estimated orientation of the user U. Then, based on the orientation and position of the user U, the state estimation unit 332 estimates that the user U is moving from the location where the user U is located in the direction of the orientation of the user U (the direction of the arrow).

[0058] (State Estimation Method 2) Next, as state estimation method 2, a method for estimating the position, orientation, and moving direction of a user and the shielding state of the terminal device 20 using reflected waves will be described with reference to Fig. 5. The state estimation unit 332 of the network server 30 estimates the position of the user U using the angle of the beam. In an environment where there are reflecting objects on all sides as shown in Fig. 5, the terminal device 20-1 and the terminal device 20-2 receive beams reflected from walls in addition to the direct wave (beam #3).

[0059] Here, beam #3 is received by terminal device 20-1 and terminal device 20-2, beam #1 is received only by terminal device 20-1, and beam #2 is received only by terminal device 20-2. Since both terminal device 20-1 and terminal device 20-2 can receive beam #3, the state estimation unit 332 estimates that user U is located in the direction (angle) of beam #3 as seen from the base station 10. Furthermore, the state estimation unit 332 compares the angle (α°) between beam #3 and beam #2 with the angle (β°) between beam #3 and beam #1, and estimates that terminal device 20-2, which receives beam #2 with a smaller angle, is behind the user (shielded). Furthermore, the state estimation unit 332 estimates the user's orientation based on the holding position of each terminal device 20 using the method described above.

[0060] (State Estimation Method 3) As state estimation method 3, a method for estimating the user's movement direction will be described using Figs. 6 to 8. Figs. 6 to 8 are diagrams for explaining the state estimation method in the first embodiment. Let X and Y be the number of horizontal beams and vertical beams of the base station 10. The information on X and Y may be held by the network server 30 as base station information 323. In the example shown in Figs. 6 to 8, X = 8 and Y = 8. The received signal vector is converted into an X x Y matrix.

[0061] Fig. 6 shows, from left to right, the received power for each beam number of each terminal device 20. For example, the diagram shown in the upper part of Fig. 6 shows the received power for each beam number of terminal device 20-1, the diagram shown in the middle part of Fig. 6 shows the received power for each beam number of terminal device 20-2, and the diagram shown in the lower part of Fig. 6 shows the received power for each beam number of terminal device 20-3.

[0062] Here, the received power vector for each beam of terminal device 20-n (n is an integer equal to or greater than 1) is expressed by the following equation (1).

[0063]

[0064] In equation (1), M represents the number of beams. A small value such as -120 dB is assigned to beams for which the received power cannot be obtained. The state estimation unit 332 calculates the average value of the received power vectors for each beam of all the terminal devices 20 based on the following equation (2).

[0065]

[0066] N in equation (2) represents the number of terminal devices 20. The average value of the received power vector for each beam of all terminal devices 20 is shown in Fig. 7. Thereafter, the state estimation unit 332 calculates the center of gravity in the X direction and the center of gravity in the Y direction shown in Fig. 7 and estimates normalized position information of the user by normalizing the center of gravity so that the average is 0 and the variance is 1 in a certain time interval. The estimated result of the normalized position information of the user is shown in Fig. 8. The state estimation unit 332 estimates the user's moving direction based on the time series of the user's normalized position information.

[0067] (State Estimation Method 4) As state estimation method 4, a method for estimating a user's position will be described using FIG. 9 . FIG. 9 is a diagram for explaining the state estimation method in the first embodiment. The state estimation unit 332 estimates the user's position using a learning approach such as a random forest algorithm. In this case, a trained model is used that is trained to output an estimation result of the user's position by using the received power for each beam of multiple terminal devices 20 as the input data set and the user's position information as the training data. The network server 30 obtains an estimation result of the user's position by inputting the received power for each beam acquired from each terminal device 20 into the trained model. In this way, the network server 30 estimates the user's position. FIG. 9A shows an estimation result of the user's position when the received power for each beam of one terminal is used, and FIG. 9B shows an estimation result of the position of a user who carries three terminals in different locations using the received power for each beam of three terminals.

[0068] According to the wireless communication system 100 configured as described above, the network server 30 comprises an acquisition unit 331 that acquires wireless information from each of the multiple terminal devices 20, including wireless quality information for each beam obtained between the base station 10 and each of the multiple terminal devices 20 held at different positions by the same user or robot, and information indicating the holding position of each of the multiple terminal devices 20, and a state estimation unit 332 that estimates the state of the user or robot or the multiple terminal devices 20 based on the wireless information acquired by the acquisition unit 331.

[0069] As described above, in the wireless communication system 100, the network server 30 performs state estimation based on wireless communication quality information (e.g., beam reception power) between the base station 10 and the target, which is acquired by multiple terminal devices 20 held by the same user or robot and located in close proximity. Because the multiple terminal devices 20 held by the same target are installed in different locations, the assigned beam IDs and beam reception power values ​​vary depending on the target's position, posture (orientation), and positional relationship with the base station 10. The network server 30 estimates the state of the target and the multiple terminal devices 20 using information obtained from the multiple terminal devices 20 that satisfy such conditions (e.g., different reception power values ​​for each beam ID). Therefore, the state can be estimated even when communication with multiple base stations is not possible or in an environment where radio wave reflectors are not installed. This enables accurate state estimation.

[0070] Here, we explain why the accuracy of state estimation can be improved by using information obtained from multiple terminal devices 20 that satisfy the following criteria: different received power values ​​for each beam ID. In low-frequency bands such as microwaves, there is little difference in received power values ​​between terminal devices 20 installed in close proximity. In contrast, in high-frequency bands such as millimeter waves, which are within the scope of application of the present invention, there may be terminal devices 20 located in close proximity but with different shielding conditions, for example, due to shielding by a user or a robot, and the received power values ​​may differ between the terminal devices 20. For example, considering a situation in which two terminal devices 20 (e.g., terminal devices 20-1 and 20-2) receive beams with the same beam ID but have different received powers (e.g., when the difference is large), it becomes possible to estimate a state in which a shield is present between terminal device 20-1 and terminal device 20-2. In other words, even if terminal device 20-1 and terminal device 20-2 are located in approximately the same position as viewed from the base station 10, their received power values ​​differ due to their different holding conditions. This improves spatial resolution, which ultimately leads to improved accuracy of state estimation.

[0071] Second Embodiment In the first embodiment, an external device (e.g., a network server) different from the multiple terminal devices belonging to a group is configured to estimate the status, etc., of users who own the multiple terminal devices. In contrast, in the second embodiment, a configuration will be described in which a master terminal among the multiple terminal devices belonging to a group estimates the status, etc., of users who own the multiple terminal devices.

[0072] Fig. 10 is a diagram showing an example of the configuration of a wireless communication system 100a according to the second embodiment. The wireless communication system 100a includes a base station 10 and a plurality of terminal devices 20a. Fig. 10 shows a case in which the wireless communication system 100a includes three terminal devices 20a-1 to 20a-3, but the number of terminal devices 20a may be any number as long as it is plural. The number of base stations 10 may also be plural. The base station 10 and each terminal device 20a are connected wirelessly.

[0073] In the wireless communication system 100a, one terminal device 20a, which is a master terminal among a plurality of terminal devices 20a belonging to the same group, estimates the status of users who own the plurality of terminal devices 20a.

[0074] The base station 10 performs the same processing as the base station 10 in the first embodiment. Note that the wireless communication system 100a does not include the network server 30, and therefore the base station 10 does not perform the processing for the network server 30 shown in the first embodiment.

[0075] The terminal devices 20a other than the master terminal perform the same processing as the terminal devices 20 in the first embodiment. Here, the terminal devices 20a other than the master terminal are normal terminal devices 20a that perform the same processing as the terminal devices 20 in the first embodiment. The terminal devices 20a other than the master terminal transmit the acquired wireless information to the master terminal. The master terminal estimates the user's state using the wireless information transmitted from each terminal device 20a other than the master terminal.

[0076] The user operates one of the multiple terminal devices 20a to be the master terminal and sets it up to function as the master terminal. Each of the multiple terminal devices 20a can determine whether it is the master terminal based on whether it has been set up as the master terminal. Each of the multiple terminal devices 20a operates as a master terminal when it has been set up to function as the master terminal. Each of the multiple terminal devices 20a operates as a normal terminal device 20a when it has not been set up to function as the master terminal.

[0077] (Configuration of terminal device 20a) Next, the configuration of terminal device 20a will be described using Fig. 11. Fig. 11 is a diagram showing an example of the configuration of terminal device 20a in the second embodiment. Terminal device 20a includes a RAN communication unit 21, a PAN communication unit 22, a reception processing unit 23, a control unit 24a, and a group terminal information storage unit 25a.

[0078] The configuration of the terminal device 20a differs from that of the terminal device 20 in that the terminal device 20a includes a control unit 24a and a group terminal information storage unit 25a instead of the control unit 24 and the group terminal information storage unit 25. The other configuration of the terminal device 20a is the same as that of the terminal device 20. The following description will focus on the differences from the terminal device 20.

[0079] The control unit 24a controls the entire terminal device 20a. The control unit 24a is configured using one or more processors such as a CPU and one or more memories. The one or more processors execute programs to realize the functions of a connection request unit 241, a wireless information acquisition unit 242, an information notification unit 243, an operation control unit 244, an acquisition unit 245, and a state estimation unit 246.

[0080] The operation control unit 244 sets the operation mode of the own device. Specifically, the operation control unit 244 sets the operation mode of the own device to operate in either normal terminal mode or master terminal mode. The normal terminal mode is a mode for operating as a normal terminal device 20a. The master terminal mode is a mode for operating as a master terminal.

[0081] For example, when the device is set to function as a master terminal, the operation control unit 244 sets the operation mode of the device to the master terminal mode. For example, when the device is not set to function as a master terminal, the operation control unit 244 sets the operation mode of the device to the normal terminal mode.

[0082] The connection request unit 241, the wireless information acquisition unit 242, and the information notification unit 243 are functional units that function when the operation mode of the terminal device 20a is the normal terminal mode. The acquisition unit 245 and the state estimation unit 246 are functional units that function when the operation mode of the terminal device 20a is the master terminal mode. The connection request unit 241, the wireless information acquisition unit 242, and the information notification unit 243 have been described in the first embodiment, so their description will be omitted.

[0083] The acquisition unit 245 acquires various types of information, such as wireless information transmitted from each terminal device 20a.

[0084] The state estimation unit 246 estimates the state based on the information stored in the group terminal information storage unit 25 a. The state estimation unit 246 estimates the state of the user, such as the user's position, the user's orientation, and the user's moving direction.

[0085] The group terminal information storage unit 25a stores group terminal information 251, terminal location information 252, and wireless information 253. The group terminal information 251 is identification information for identifying each terminal device 20 belonging to the same group. The terminal location information 252 is information indicating the location of each terminal device 20a. The terminal location information 252 is associated with the identification information of the terminal device 20a. Note that if there are multiple groups in the wireless communication system 100a, the group terminal information storage unit 25a may store the terminal location information 252 separately for each group.

[0086] The wireless information 253 is wireless information of each terminal device 20a other than the master terminal. The wireless information 253 is associated with the identification information of the terminal device 20a. If multiple groups exist in the wireless communication system 100a, the group terminal information storage unit 25a may store the wireless information 253 for each group.

[0087] (Operation of wireless communication system 100a) Next, the operation of the wireless communication system 100a in the second embodiment will be described using FIG. 12. FIG. 12 is a sequence diagram showing the processing flow of the wireless communication system 100a in the second embodiment. In the description of FIG. 12, three terminal devices 20a will be used as an example, and in FIG. 12, the three terminal devices 20a will be described as a terminal device group. In the description of FIG. 12, branch numbers will be added to distinguish the functional units of each terminal device 20a. For example, the functional units included in terminal device 20a-1 will be added with "-1" in the description. In addition, in the description of FIG. 12, a case will be described in which terminal device 20-1 is the master terminal.

[0088] Terminal devices 20a-2 to 20a-3 other than the master terminal register the storage locations of terminal devices 20a-2 to 20a-3 in response to user operation (step S201). After the storage location information is registered, terminal devices 20a-2 to 20a-3 make a connection request to base station 10. Here, for convenience of explanation, a case will be described in which terminal devices 20a-2 to 20a-3 make a connection request to base station 10 at different times, but any of terminal devices 20a-2 to 20a-3 may make a connection request to base station 10 at the same time.

[0089] The connection request unit 241-2 of the terminal device 20a-2 transmits a connection request to the base station 10 (step S202). The base station 10 receives the connection request transmitted from the terminal device 20a-2. The base station 10 transmits a reference signal to the terminal device 20a-2 in response to the received connection request (step S203). At this time, the base station 10 transmits the reference signal by switching between multiple beams over time. The RAN communication unit 21-2 of the terminal device 20a-2 receives the reference signal transmitted from the base station 10.

[0090] The radio information acquisition unit 242-2 of the terminal device 20a-2 measures the received power based on the received reference signal (step S204). The radio information acquisition unit 242-2 performs this process for each beam formed by the base station 10. This allows the radio information acquisition unit 242-2 to acquire information on the received power for each beam formed by the base station 10. The radio information acquisition unit 242-2 transmits feedback information, in which the terminal identification information and the acquired information on the received power for each beam ID are associated, to the base station 10 via the RAN communication unit 21-2 (step S205).

[0091] The base station 10 receives the feedback information transmitted from the terminal device 20a-2. The base station 10 assigns a beam to the terminal device 20a-2 based on the received feedback information (step S206). For example, the base station 10 assigns to the terminal device 20a-2 a beam corresponding to the beam ID with the maximum received power among the received powers for each beam ID included in the feedback information. The base station 10 transmits to the terminal device 20a-2 a beam notification including the beam ID corresponding to the beam assigned to the terminal device 20a-2 and information indicating the frequency band (step S207).

[0092] The RAN communication unit 21-2 of the terminal device 20a-2 receives the beam notification transmitted from the base station 10. The radio information acquisition unit 242-2 of the terminal device 20a-2 acquires the received beam notification. The radio information acquisition unit 242-2 outputs terminal information including information indicating the beam ID and frequency band contained in the acquired beam notification, information indicating the reception power of the beam corresponding to the beam ID, and information indicating the holding position registered in the terminal device 20a-2 to the information notification unit 243-2. ​​The information notification unit 243-2 transmits the terminal information output from the radio information acquisition unit 242-2 to the terminal device 20a-1, which is the master terminal, via the PAN communication unit 22-2 (step S208).

[0093] The terminal device 20a-3 also performs the above-described processes from step S202 to step S208. As a result, the master terminal receives the terminal information transmitted from each of the terminal devices 20a-2 to 20a-3. The PAN communication unit 22-1 of the master terminal receives the terminal information from each of the terminal devices 20a-2 to 20a-3.

[0094] The acquisition unit 245-1 of the master terminal acquires the terminal information of each of the terminal devices 20a-2 to 20a-3 received by the PAN communication unit 22-1. The acquisition unit 245-1 stores the acquired terminal information of each of the terminal devices 20a-2 to 20a-3 in the group terminal information storage unit 25a. For example, the acquisition unit 245-1 associates information indicating a holding position included in the terminal information with identification information of the terminal device 20a and stores it as terminal holding position information 252. For example, the acquisition unit 245-1 associates information indicating a beam ID, a frequency band, and information indicating reception power included in the terminal information with identification information of the terminal device 20a and stores it as radio information 253.

[0095] The state estimation unit 246 performs state estimation using the information stored in the group terminal information storage unit 25a (step S209). The state estimation method will be described below.

[0096] (State Estimation Method 1) As state estimation method 1 in the second embodiment, a method for estimating a user's orientation will be described using Fig. 5. Here, the terminal devices 20-1 and 20-2 shown in Fig. 5 will be replaced with terminal devices 20a-1 and 20a-2, respectively. Assume that a user U holds terminal device 20a-1 on his right arm and terminal device 20a-2 on his left arm. Here, the base station 10 is capable of emitting five beams #1 to #5 with different radiation angles in the horizontal direction.

[0097] When the user U is moving in the direction of the arrow, the terminal device 20a-1 is in a line-of-sight situation, and the terminal device 20a-2 is in a state of being blocked by the user U. The terminal devices 20a-1 and 20a-2 can receive beam #3 as a direct beam from the base station 10. The received power of beam #3 of the terminal devices 20a-1 and 20a-2 is respectively represented by R ３ （１） , R ３ （２） When the user U is blocked, the received power is attenuated. ３ （１） >R ３ （２） This becomes:

[0098] On the other hand, if there is a reflecting object such as a wall indoors, the terminal device 20a-2 can receive beams other than beam #3. In the example shown in Fig. 5, for example, the terminal device 20a-2 can receive beam #2 as a reflected wave. The state estimation unit 246 of the master terminal estimates the orientation of the user U based on the holding positions of the terminal device 20a-1 and the terminal device 20a-2 (for example, information indicating the right arm and the left arm), the received power of each beam, and the beam ID corresponding to the received beam.

[0099] For example, the master terminal acquires, as terminal information, from the terminal device 20a-1 held on the right arm of the user U, information indicating that the terminal device is held on the right arm, a beam ID corresponding to the received beam #3, and information indicating the received power of beam #3. Furthermore, for example, the master terminal acquires, as terminal information, from the terminal device 20a-2 held on the left arm of the user U, information indicating that the terminal device is held on the left arm, a beam ID corresponding to each of the received beams #2 and #3, and information indicating the received power of each of beams #2 and #3. As a result, the state estimation unit 246 of the master terminal estimates that the user U is facing in a direction in which the terminal device 20a-1 held on the right arm can receive beam #2 and the terminal device 20a-2 held on the left arm can receive beams #2 and #3. For example, the state estimation unit 246 of the master terminal estimates that the user U is facing in the direction of the arrow.

[0100] (State Estimation Method 2) As state estimation method 2 in the second embodiment, the state estimation unit 246 of the master terminal estimates the user's position using a learning approach such as a random forest algorithm. This process has been described in (State Estimation Method 4) of the first embodiment, so a detailed description of the process will be omitted.

[0101] According to the wireless communication system 100a configured as described above, even if any one of the multiple terminal devices 20 belonging to the same group operates as the master terminal, it is possible to obtain the same effects as in the first embodiment.

[0102] (Variation of the Second Embodiment) The master terminal may be configured to acquire base station information 323, as in the first embodiment. The master terminal may acquire information about the base station 10 by any method. For example, the master terminal may acquire information about the base station 10 from the base station 10, or may acquire information about the base station 10 by a user registering with the master terminal, or may acquire information about the base station 10 from an external device.

[0103] When configured in this manner, the state estimation unit 246 of the master terminal may estimate the user's position and movement direction as in the first embodiment (state estimation method 1). The state estimation unit 246 of the master terminal may also estimate the user's position, orientation, movement direction, and occlusion state of the terminal device 20a based on reflected waves as in the first embodiment (state estimation method 2). The state estimation unit 246 of the master terminal may also estimate the user's movement direction as in the first embodiment (state estimation method 3).

[0104] The terminal devices 20, 20a and network server 30 described above may be implemented by a computer. In this case, a program for implementing this function may be recorded on a computer-readable recording medium, and the program may be loaded into a computer system and executed. Note that the term "computer system" as used herein includes hardware such as an operating system (OS) and peripheral devices. Furthermore, the term "computer-readable recording medium" refers to portable media such as flexible disks, magneto-optical disks, read-only memories (ROMs), and CD-ROMs, as well as storage devices such as hard disks built into computer systems.

[0105] Furthermore, the term "computer-readable recording medium" may include a medium that dynamically stores a program for a short period of time, such as a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line, or a medium that stores a program for a certain period of time, such as a volatile memory within a computer system that serves as a server or client in such a case. The program may also be one that realizes part of the above-mentioned functions, or one that can realize the above-mentioned functions in combination with a program already stored in the computer system, or one that can be realized using a programmable logic device such as an FPGA (Field Programmable Gate Array).

[0106] Although an embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes designs within the scope of the gist of the present invention.

[0107] The present invention is applicable to wireless access networks.

[0108] DESCRIPTION OF SYMBOLS 10... base station, 20, 20-1 to 20-3, 20a, 20a-1 to 20a-3... terminal device, 21... RAN communication unit, 22... PAN communication unit, 23... reception processing unit, 24, 24a, 33... control unit, 25... group terminal information storage unit, 30... network server, 31... communication unit, 32... storage unit, 100, 100a... wireless communication system, 241... connection request unit, 242... wireless information acquisition unit, 243... information notification unit, 244... operation control unit, 245, 331... acquisition unit, 246, 332... state estimation unit, 251... group terminal information, 252, 321... terminal held location information, 253, 322... wireless information, 323... base station information

Claims

1. A network server comprising: a base station capable of using multiple beams with directivity in different directions; an acquisition unit that acquires wireless information from each of multiple terminal devices, the wireless information including wireless quality information for each beam obtained between the base station and each of multiple terminal devices held at different positions by the same object, and information indicating the holding position of each of the multiple terminal devices; and a state estimation unit that performs state estimation of the object or the multiple terminal devices based on the wireless information acquired by the acquisition unit.

2. The network server according to claim 1, wherein the state estimation unit estimates at least one of the position, orientation, or direction of movement of the target, or the occlusion state of any of the plurality of terminal devices.

3. A terminal device that operates as a master terminal among multiple terminal devices belonging to the same group, comprising: a base station that can use multiple beams with directivity in different directions; an acquisition unit that acquires from each of the other terminal devices wireless information including wireless quality information for each beam obtained between each of multiple terminal devices other than the own device among multiple terminal devices held by the same object at different positions, and information indicating the holding position of each of the other terminal devices; and a state estimation unit that performs state estimation of the object or the other terminal devices based on the wireless information acquired by the acquisition unit.

4. The terminal device according to claim 3, wherein the state estimation unit estimates at least one of the position, orientation, or direction of movement of the target, or an occlusion state of one of the other terminal devices.

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