Information processing device, base station, and program

Abstract

This information processing device (20) comprises: an acquisition unit (22) that acquires reception times at which each of a plurality of antennas arranged in a predetermined plane received a reflected wave; a first estimation unit (23) that estimates, on the basis of the reception times, virtual reception times at which it is assumed that virtual antennas will receive the reflected wave if more virtual antennas than antennas are virtually arranged in the predetermined plane; and a second estimation unit (24) that estimates, on the basis of the virtual reception times, directions from which it is assumed that the reflected wave will arrive at the virtual antennas.

Description

Information Processing Apparatus, Base Station, and Program

[0001] The present invention relates to an information processing apparatus, a base station, and a program.

[0002] Patent Document 1 discloses a technique in which a plurality of receiving antennas receive reflected waves obtained by reflecting a transmission wave by a predetermined object, and based on the phases of the reflected waves received by the plurality of receiving antennas and the path differences of the respective reflected waves, the direction in which the reflected waves arrive at the receiving antennas is estimated.

[0003] Japanese Patent Application Laid-Open No. 2021-73452

[0004] In a technique for receiving reflected waves reflected by an object with a plurality of receiving antennas and estimating the direction in which the object exists, the estimation accuracy depends on the number of receiving antennas that receive the reflected waves. However, due to constraints on the frequency of the transmission wave and the antenna size, it may not be possible to secure a sufficient number of receiving antennas for estimating the position of the object.

[0005] An information processing apparatus according to an aspect of the present invention aims to improve the estimation accuracy of the direction in which an object exists.

[0006] In order to solve the above problems, an information processing apparatus according to the present invention includes an acquisition unit that acquires reception times at which a plurality of antennas arranged on a predetermined plane respectively receive reflected waves obtained by reflecting a predetermined transmission wave from the surface of an object, a first estimation unit that estimates virtual reception times at which each of a plurality of virtual antennas, which are more in number than the plurality of antennas, would receive the reflected waves when the plurality of virtual antennas are virtually arranged on the predetermined plane, based on each reception time acquired by the acquisition unit, and a second estimation unit that estimates the direction in which the reflected waves would arrive at each of the plurality of virtual antennas, based on the virtual reception times estimated by the first estimation unit.

[0007] Each aspect of the present invention may be implemented by a computer, in which case a control program for the information processing device that enables the computer to implement the information processing device by operating the computer as each part (software element) of the information processing device, and a computer-readable recording medium on which the program is recorded, also fall within the scope of the present invention.

[0008] This can improve the accuracy of estimating the direction in which an object is located.

[0009] This figure shows an example of a base station configuration according to one embodiment of the present invention. This figure is used to explain the principle of direction estimation based on the reception time of reflected waves. This block diagram shows an example of an information processing device according to one embodiment of the present invention. This figure is used to explain a virtual antenna.

[0010] Figure 1 is a diagram showing an example of the configuration of a base station according to one embodiment of the present invention. The position estimation system SYS shown in Figure 1 includes a base station 1 that conforms to the standard specifications of fifth-generation or later mobile communication systems. The base station 1 is, for example, a base station that performs wireless communication using the Massive MIMO method and comprises an array antenna 10 and an information processing device 20. Hereinafter, as defined by the arrows in Figure 1, the X-axis direction and Y-axis direction are defined with respect to the transmitting and receiving surface 11 of the array antenna 10. The transmitting and receiving surface 11 is an example of a predetermined plane.

[0011] Multiple antenna units A are arranged in a two-dimensional array on the transmitting and receiving surface 11 of the array antenna 10. The multiple antenna units A are arranged at equal intervals of a first interval d in the X-axis direction and the Y-axis direction, respectively. The first interval d is determined based on the wavelength λ of the signals transmitted and received by the antenna units A. For example, the first interval d is set to 1 / 2 or 1 / 4 of the wavelength of the signals transmitted and received by the antenna units A.

[0012] The information processing device 20 is a server device that controls the array antenna 10 and is realized by the base station 1 and the computing resources arranged around the base station 1. The information processing device 20 has a RIC (RAN Intelligent Controller) that uses at least one of the technologies of artificial intelligence and machine learning to improve the efficiency and performance of a radio access network (RAN).

[0013] The information processing device 20 causes a transmission wave W of a predetermined frequency f to be transmitted from each antenna unit A of the array antenna 10 toward the object 30. T The frequency f is, for example, 2.5 GHz. The wavelength λ of a signal with a frequency f of 2.5 GHz is approximately 12 cm. The transmission wave W T is reflected by the surface of the object 30, and a reflected wave W T corresponding to the transmission wave W R arrives at the transmission / reception surface 11 of the array antenna 10.

[0014] The information processing device 20 estimates the position of the object 30 with respect to the array antenna 10 based on the transmission time t T when each antenna unit A transmits the transmission wave W T and the reception time t R when each antenna unit A receives the reflected wave W R For example, the information processing device 20 estimates the length L of the propagation path between the array antenna 10 and the object 30 based on the time difference between the transmission time t T when each antenna unit A transmits the transmission wave W T and the reception time t R when each antenna unit A receives the reflected wave W R Further, the information processing device 20 estimates the incident angle θ indicating the direction in which the reflected wave W R arrives at each antenna unit A based on the reception time t R when each antenna unit A receives the reflected wave W R The length L of the propagation path between the array antenna 10 and the object 30 and the reflected wave W RBy estimating the incident angle θ, which indicates the direction in which the rays arrive at each antenna unit A, the position of the object 30 can be estimated.

[0015] (Principle of direction estimation) Figure 2 shows the reflected wave W. R Reception time t R This figure is used to explain the principle of direction estimation based on [the given method]. Multiple antenna units A are arranged on the transmitting / receiving surface 11 of the array antenna 10 at a first interval d in the X-axis direction. In Figure 2, for the sake of simplicity, the reflected wave W is shown. R It is assumed that this is a plane wave. Reflected wave W R The rays are directed in the direction R from the transmitting / receiving surface 11 to the direction in which each antenna unit A extends. A It is tilted by an incident angle θ relative to the reflected wave W. R Wavefront WF R The antenna is tilted by θ with respect to the X-axis of the transmitting / receiving surface 11 of the array antenna 10. Under these conditions, the reflected wave W reaches two adjacent antenna units A in the X-axis direction. R The path lengths L of the transport paths differ from each other by dsinθ. Therefore, if the speed of light in air is c, the two adjacent antenna units A in the X-axis direction reflect the wave W. R Received at time t R The time difference Δt1 is given by Δt1 = dsinθ / c. Two adjacent antenna units A in the X-axis direction reflect the wave W. R Received at time t R If the time difference is Δt1, the value of the angle of incidence θ can be estimated as arcsin{c・Δt1 / d}.

[0016] The information processing device 20 estimates the length L of the transport path between the array antenna 10 and the object 30 for each position of the antenna unit A of the array antenna 10, and the reflected wave W RThis involves estimating the incidence angle θ, which indicates the direction in which the signal arrives at each antenna unit A of the array antenna 10. Then, the position of the object 30 is estimated based on the planar distribution of the estimation results for each position of the antenna unit A. In this method of estimating the position of the object 30, the estimation accuracy improves as the number of antenna units A arranged on the transmitting / receiving surface 11 of the array antenna 10 increases. However, as mentioned above, the first interval d of the antenna units A is determined based on the wavelength λ of the signal transmitted and received by the antenna units A, so there is a limit to the number of antenna units A that can actually be arranged on the transmitting / receiving surface 11 of the array antenna 10.

[0017] (Position estimation using super-resolution technology) The information processing device 20 virtually increases the number of antenna units A arranged on the transmitting / receiving surface 11 of the array antenna 10 using super-resolution technology utilizing a RIC or the like. By virtually increasing the number of antenna units A, the information processing device 20 improves the resolution for estimating the position of the object 30 and improves the accuracy of estimating the position of the object 30.

[0018] Figure 3 is a block diagram showing an example of an information processing device 20 according to one embodiment of the present invention. The information processing device 20 functions, for example, as a transmission unit 21, an acquisition unit 22, a first estimation unit 23, a second estimation unit 24, a third estimation unit 25, and a fourth estimation unit 26.

[0019] The transmitting unit 21 controls the antenna unit A of the array antenna 10 to transmit a predetermined wave W T The transmitting unit 21 transmits the transmission wave W. T The transmission time t T Information indicating this is input to the third estimation unit 25.

[0020] The acquisition unit 22 receives reflected waves W from multiple antenna units A arranged on the transmitting / receiving surface 11 of the array antenna 10. R The reception time t was received. R The antenna unit A obtains the reflected wave W. R The reception time t was received. R The information provided includes the antenna position of each antenna unit A and the reception time t of each antenna unit A. RIt is sufficient to have a data structure that clearly shows the correspondence between them. For example, if antenna unit A is reflected wave W R The reception time t was received. R The information indicating this may be a two-dimensional array having the same number of elements as the number of antenna units A arranged on the transmitting / receiving surface 11 of the array antenna 10. Alternatively, it may be image data having the same number of pixels as the number of antenna units A arranged on the transmitting / receiving surface 11 of the array antenna 10.

[0021] The first estimation unit 23 determines that if more virtual antennas B than the number of antenna units A are virtually placed on the transmitting / receiving surface 11 of the array antenna 10, then each virtual antenna B will reflect the wave W R The virtual reception time t that is expected to be received VR The reception time t of each antenna unit A acquired by the acquisition unit 22 R We estimate based on this.

[0022] Figure 4 is a diagram used to explain virtual antenna B. In Figure 4, multiple virtual antennas B are virtually arranged on the transmitting / receiving surface 11 of the array antenna 10 as if they were arranged at equal intervals of a second interval in both the X-axis and Y-axis directions. In Figure 4, the second interval is half the first interval d. In reality, virtual antennas B are not arranged on the transmitting / receiving surface 11 of the array antenna 10, but the virtual reception time t is calculated as if virtual antennas B were arranged. VR This is estimated. In Figure 4, the number of virtual antennas B virtually placed on the transmitting / receiving surface 11 of the array antenna 10 is four times the number of antenna units A actually placed on the transmitting / receiving surface 11 of the array antenna 10.

[0023] The first estimation unit 23 uses upscaling technology to determine the reception time t of each antenna unit A acquired by the acquisition unit 22. R Based on this, the virtual reception time t of each virtual antenna B VRThe first estimation unit 23 estimates the virtual reception time t of each virtual antenna B. VR RIC may be used for estimation.

[0024] The first estimation unit 23, for example, determines the reception time t of each antenna unit A acquired by the acquisition unit 22. R The virtual reception time t of each virtual antenna B is input to the trained model M. VR The estimated value is obtained from the trained model M. The trained model M is, for example, the reception time t of all antenna units A. R The data array and the virtual reception time t of all virtual antennas B. VR This is a convolutional neural network (CNN) generated by learning from multiple training data sets consisting of pairs of data arrays. The trained model M is pre-stored in the information processing device 20. The first estimation unit 23 obtains the virtual reception time t of each virtual antenna B from the trained model M. VR This is input to the second estimation unit 24 and the third estimation unit 25.

[0025] The second estimation unit 24 calculates the virtual reception time t of each virtual antenna B estimated by the first estimation unit 23. VR Based on this, reflected wave W R The second estimation unit 24 estimates the incident angle θ, which indicates the direction in which the reflected wave W is expected to arrive at each virtual antenna B. The second estimation unit 24 estimates the reflected wave W, for example, in the following way. R We estimate the incidence angle θ, which indicates the direction in which the signal is expected to arrive at each virtual antenna B.

[0026] The second estimation unit 24 selects from among the virtual antennas B estimated by the first estimation unit 23 the virtual reception time t VR Information is obtained indicating the antenna position of each virtual antenna B (hereinafter referred to as the earliest virtual antenna) that has the earliest reception time t. VR The earliest reception time t e It should be written as follows.

[0027] The second estimation unit 24 determines the virtual reception time t of each virtual antenna B. VR And, the reception time t e The second estimation unit 24 calculates the time difference Δt2 between each virtual antenna B and the first virtual antenna. The second estimation unit 24 then calculates the interval d2 between the antenna position of each virtual antenna B and the antenna position of the first virtual antenna. Based on the time difference Δt2 and interval d2 calculated for each virtual antenna B, the second estimation unit 24 calculates the reflected wave W R The second estimation unit 24 estimates the incident angle θ, which indicates the direction in which the rays are expected to arrive at each virtual antenna B. The second estimation unit 24 estimates the incident angle θ as arcsin{c・Δt² / d²}. The second estimation unit 24 inputs the estimated result of the incident angle θ to the fourth estimation unit 26.

[0028] The second estimation unit 24 determines the reception time t of each antenna unit A acquired by the acquisition unit 22. R Based on this, reflected wave W R The angle of incidence θ, which indicates the direction in which the signal arrived at each antenna unit A, may be further estimated. For example, from among the antenna units A, the reception time t R The antenna position of antenna unit A that has the earliest reception time t is obtained, and the earliest reception time t for each antenna unit A is obtained. R The time difference and the reception time t R The distance between the antenna position of antenna unit A and the position where the reflection wave W occurs earliest is calculated, and the reflected wave W is based on these values. R The angle of incidence θ that arrived at each antenna unit A may be estimated.

[0029] The third estimation unit 25 determines the virtual reception time t of each virtual antenna B estimated by the first estimation unit 23. VR Then, the transmitting unit 21 transmits the wave W T The transmission time t T Based on this, the transmission wave W assumed to be between each virtual antenna B and the object 30 T and reflected wave W R The length L of the transport path is estimated. The third estimation unit 25 estimates the length L of the transport path from each virtual antenna B to the object 30, for example, L = c(t VR -t T ) is estimated to be the speed of light in air.

[0030] The third estimation unit 25 determines the reception time t of each antenna unit A acquired by the acquisition unit 22. R Then, the transmitting unit 21 transmits the wave W T The transmission time t T Based on this, the transmitted wave W between each antenna unit A and the object 30 T and reflected wave W R The length L of the transport path may be further estimated. The third estimation unit 25 estimates the length L of the transport path from each antenna unit A to the object 30 as, for example, L = c(t R -t T ) We may also assume that this is the case.

[0031] The fourth estimation unit 26 estimates the position of the object 30 based on the estimation results of the second estimation unit 24 and the estimation results of the third estimation unit 25. Reflected wave W R The method for estimating the position of the object 30 based on multiple reception results regarding the reception of signals may use various known methods.

[0032] Since the number of virtual antennas B virtually arranged on the transmitting / receiving surface 11 of the array antenna 10 is greater than the number of antenna units A arranged on the transmitting / receiving surface 11 of the array antenna 10, the reception time t of each antenna unit A R The accuracy of estimating the position of object 30 is improved compared to when only that method is used for estimation.

[0033] [Modification] In the above embodiment, the multiple virtual antennas B are virtually arranged on the transmitting / receiving surface 11 of the array antenna 10 at equal intervals of d / 2 in the X-axis direction and the Y-axis direction, respectively. However, the second interval between two adjacent virtual antennas B is not limited to d / 2. Any value can be adopted for the second interval as long as it is a value that virtually arranges the virtual antennas B more densely than the antenna units A arranged on the transmitting / receiving surface 11 of the array antenna 10.

[0034] In the above embodiment, the transmitting unit 21 transmits a wave W from a plurality of antenna units A arranged on the transmitting / receiving surface 11 of the array antenna 10. T It was explained as transmitting the wave W. TThe transmission may be made from an antenna other than antenna unit A of the array antenna 10, and the transmitted wave W T The antenna that transmits the signal may be located outside base station 1. Transmitted wave W T If the antenna that transmits the signal is located outside the base station 1, the transmitting unit 21 of the information processing device 20 receives the transmission wave W from the control device that controls the antenna located outside the base station 1. T The transmission time t T Alternatively, the transmission wave W may be obtained from a portion of the multiple antenna units A arranged on the transmitting / receiving surface 11 of the array antenna 10. T You may also choose to have it sent.

[0035] [Example of implementation by software] The functions of the information processing device 20 (hereinafter referred to as "device") can be realized by a program that causes the device to function as a computer, and by a program that causes each control block of the device to function as a computer.

[0036] In this case, the device includes a computer having at least one control device (e.g., a processor) and at least one storage device (e.g., memory) as hardware for executing the program. By executing the program using this control device and storage device, the functions described in each of the embodiments are realized.

[0037] The above program may be recorded on one or more computer-readable recording media, not temporary ones. These recording media may or may not be provided by the above device. In the latter case, the program may be supplied to the above device via any wired or wireless transmission medium.

[0038] Furthermore, some or all of the functions of each of the above control blocks can also be realized by logic circuits. For example, an integrated circuit in which logic circuits functioning as each of the above control blocks are formed is also included in the scope of the present invention. In addition, it is also possible to realize the functions of each of the above control blocks by, for example, a quantum computer.

[0039] Furthermore, each process described in the above embodiments may be performed by AI (Artificial Intelligence). In this case, the AI ​​may operate on the control device described above, or it may operate on another device (for example, an edge computer or a cloud server).

[0040] [Summary] An information processing device according to embodiment 1 of the present invention includes: an acquisition unit that acquires the reception time at which a plurality of antennas arranged in a predetermined plane each receive a reflected wave obtained by reflecting a predetermined transmission wave off the surface of an object; a first estimation unit that estimates, based on the reception times acquired by the acquisition unit, a virtual reception time at which each of the plurality of virtual antennas is assumed to receive the reflected wave when a plurality of virtual antennas, more than the plurality of antennas, are virtually arranged in the predetermined plane; and a second estimation unit that estimates the direction in which the reflected wave is assumed to arrive at each of the plurality of virtual antennas based on the virtual reception time estimated by the first estimation unit.

[0041] According to the above configuration, when more virtual antennas than the number of antennas actually placed on a given plane are virtually placed on that plane, the virtual reception time at which each of the virtual antennas is expected to receive reflected waves is estimated based on the individual reception times received by each of the multiple antennas. This allows the number of antennas that can be virtually placed on the given plane to be increased. Therefore, the accuracy of estimating the direction in which an object exists can be improved.

[0042] An information processing device according to embodiment 2 of the present invention may further include, in embodiment 1 above, a transmitting unit that causes each of the plurality of antennas to transmit a predetermined transmission wave, and a third estimation unit that estimates the length of the carrier path between the transmission wave and the reflected wave, which is assumed to be between the virtual antenna and the object, based on the transmission time when each of the plurality of antennas transmits the predetermined transmission wave and the virtual reception time.

[0043] According to the above configuration, since the length of the transmission path between the antenna and the object is estimated based on the transmission time and the virtual reception time, the estimation accuracy of the distance to the object can be improved.

[0044] In the information processing apparatus according to Embodiment 3 of the present invention, in the above Embodiment 1 or 2, the plurality of antennas may be arranged at equal intervals with a first interval in the predetermined plane, and the plurality of virtual antennas may be virtually arranged as if they are arranged at equal intervals with a second interval shorter than the first interval in the predetermined plane.

[0045] The interval between adjacent virtual antennas is shorter than the interval between adjacent antennas. According to the above configuration, the direction in which the object exists can be accurately estimated regardless of the positional relationship between the plurality of antennas and the object.

[0046] The base station according to Embodiment 4 of the present invention may be configured to include the information processing apparatus according to any one of the above Embodiments 1 to 3 and the plurality of antennas.

[0047] The program according to Embodiment 5 of the present invention is a program for causing a computer to function as the information processing apparatus according to any one of the above Embodiments 1 to 3, and causes the computer to function as the acquisition unit, the first estimation unit, and the second estimation unit.

[0048] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. Furthermore, by combining the technical means disclosed in each embodiment, new technical features can be formed.

[0049] 1 Base station 10 Array antenna 11 Transmission / reception surface 20 Information processing apparatus 21 Transmission unit 22 Acquisition unit 23 First estimation unit 24 Second estimation unit 25 Third estimation unit 26 Fourth estimation unit 30 Object A Antenna unit B Virtual antenna W T Transmission wave W R Reflected wave d First interval t T Transmission time t RReception time t VR Virtual reception time θ Incident angle

Claims

1. An information processing device comprising: an acquisition unit that acquires the reception time at which a plurality of antennas arranged in a predetermined plane each receive a reflected wave obtained by reflecting a predetermined transmission wave off the surface of an object; a first estimation unit that estimates, based on the reception times acquired by the acquisition unit, a virtual reception time at which each of the plurality of virtual antennas is assumed to receive the reflected wave when a plurality of virtual antennas, more than the plurality of antennas, are virtually arranged in the predetermined plane; and a second estimation unit that estimates the direction in which the reflected wave is assumed to arrive at each of the plurality of virtual antennas based on the virtual reception time estimated by the first estimation unit.

2. The information processing apparatus according to claim 1, further comprising: a transmitting unit that causes each of the plurality of antennas to transmit a predetermined transmission wave; and a third estimation unit that estimates the length of the carrier path of the transmission wave and the reflected wave assumed to be between the virtual antenna and the object, based on the transmission time when the predetermined transmission wave was transmitted from each of the plurality of antennas and the virtual reception time.

3. The information processing apparatus according to claim 1, wherein the plurality of antennas are arranged at equal intervals at a first interval on the predetermined plane, and the plurality of virtual antennas are virtually arranged as if they were lined up at equal intervals at a second interval shorter than the first interval on the predetermined plane.

4. A base station comprising the information processing device according to any one of claims 1 to 3, and the plurality of antennas.

5. A program for causing a computer to function as an information processing device according to claim 1, wherein the computer functions as the acquisition unit, the first estimation unit, and the second estimation unit.

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