Terminal possessor detection device and terminal possessor detection method

Abstract

To improve estimation accuracy for estimating a position of a possessor of a transmission terminal from an angle spectrum of reception intensity.SOLUTION: A terminal possessor detection device includes a reception unit 300 that receives a radio wave from a transmission terminal present in a monitoring space, a position detection unit 200 that detects positions of a plurality of persons present in the monitoring space, a storage unit 111 that stores in advance structure information 112 indicating information of a reflectance and a spatial structure of a radio wave at each place in the monitoring space, a propagation information calculation unit 120 that calculates, for each of the plurality of persons, a theoretical value of a reception intensity in when an indirect wave of a radio wave transmitted from a position of each of the plurality of persons is received at a position of the reception unit 300 on the basis of the structure information 112 and position information of the person, and a comparison determination unit 160 that compares an actual measurement value and the theoretical value of reception intensity of an indirect wave component of the radio wave transmitted from the transmission terminal among the plurality of persons, and determines a person who possesses the transmission terminal.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a terminal holder detection device and a terminal holder detection method. [Background technology]

[0002] In recent years, in order to prevent information leaks, there has been a demand to detect anyone who brings a transmitting device such as a smartphone into a highly confidential room. The following Patent Document 1 discloses a technology for estimating the position of a transmitting terminal, which calculates an actual measured value of the angular spectrum (i.e., the distribution of the reception strength of radio waves in each direction) from the received signal of the receiving device, detects the position of a person in a room, calculates a theoretical value of the angular spectrum of the reception strength at the receiving device when radio waves are transmitted from this detected position, and compares the theoretical value with the actual measured value to detect the holder of the transmitting terminal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6396355 Summary of the Invention [Problem to be solved by the invention]

[0004] The radio waves received by a receiving device from a transmitting terminal include direct waves that reach the receiving device directly from the transmitting terminal and indirect waves that reach the receiving device after being reflected by some object. The influence of direct waves on the angular spectrum is dominant, which can reduce the accuracy of detecting the person carrying the transmitting terminal. For example, if multiple people are positioned in the same direction as the receiving device, similar theoretical values ​​of the angular spectrum will be calculated for these people, which could make it impossible to distinguish which person is carrying the device.

[0005] Furthermore, for example, if the receiving device is shielded (occluded) from direct waves, various angular spectra are observed depending on the degree of occlusion, and there is a risk that an unrelated person may be mistakenly detected as the carrier. The present invention has been made in consideration of the above-mentioned problems, and has as its object to improve the detection accuracy of detecting the position of the carrier of a transmitting terminal from the angular spectrum of reception strength. [Means for solving the problem]

[0006] A terminal holder detection device according to one embodiment of the present invention comprises a receiving unit that receives radio waves from a transmitting terminal present within a monitored space; a position detection unit that detects the positions of multiple people present within the monitored space; a memory unit that pre-stores structural information indicating the reflectivity of radio waves and spatial structure information at various locations within the monitored space; a propagation information calculation unit that calculates, for each of the multiple people, a theoretical value of the reception strength when the indirect wave of the radio waves transmitted from the position of each of the multiple people is received at the position of the receiving unit based on the structural information and the position information of the people; and a comparison and determination unit that compares the actual measured value and theoretical value of the reception strength of the indirect wave component of the radio waves transmitted from the transmitting terminal among the multiple people, and determines which person is carrying the transmitting terminal. [Effects of the Invention]

[0007] According to the present invention, it is possible to improve the accuracy of detecting the position of the carrier of a transmitting terminal from the angular spectrum of reception strength. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram showing how a terminal owner detection system according to an embodiment is installed and operated; [Figure 2] 1 is a top view of an example of how a terminal owner detection system according to an embodiment of the present invention is installed and operated; [Figure 3] 1 is a block diagram illustrating an example of a schematic configuration of a terminal owner detection system according to an embodiment of the present invention. [Figure 4] FIG. 10 is a diagram showing an example of actual measured values ​​of the angular spectrum of radio waves received by a receiving device. [Figure 5] 10(a) to 10(c) are diagrams showing examples of theoretical values ​​of angular spectra when radio waves transmitted from the positions of persons 40, 50, and 60, respectively, are received at the position of the receiving device. [Figure 6] 1 is a bird's-eye view of an example of a situation in which a plurality of people are positioned in the same direction as seen from a receiving device. [Figure 7] FIG. 10 is a diagram showing an example of measured values ​​of the angular spectrum of an indirect wave of a radio wave received by a receiving device. [Figure 8] 10(a) to 10(c) are diagrams showing examples of theoretical values ​​of angular spectra when indirect waves of radio waves transmitted from the positions of persons 40, 50, and 60, respectively, are received at the position of the receiving device. [Figure 9] 10(a) to 10(d) are diagrams illustrating an example of a method for calculating the measured values ​​of the angular spectrum of an indirect wave. [Figure 10] FIG. 10 is an explanatory diagram of an example of a method for calculating the similarity between the actually measured values ​​of the angular spectrum of the indirect wave calculated from FIGS. 9(a) to 9(d) and the theoretical values. [Figure 11] 10(a) and 10(b) are overhead views showing an example of a receiving device shielded from direct waves. [Figure 12] 10 is a flowchart illustrating an example of a terminal owner detection method according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments of the present invention shown below are merely examples of devices and methods for embodying the technical concept of the present invention, and the technical concept of the present invention does not limit the structure, arrangement, etc. of the components to those described below. The technical concept of the present invention can be modified in various ways within the technical scope defined by the claims.

[0010] In the following, a preferred embodiment of the present invention will be described with reference to the drawings, in which a terminal holder detection system according to the present invention is installed and operated in a highly confidential room as a monitored space. In this embodiment, the transmitting terminal is assumed to be a smartphone or a tablet terminal. The reason for this is that in recent years, smartphones and tablet devices have become smaller and more powerful, making it possible to send large amounts of information with simple operations. As a result, even if such devices are hidden in a bag or clothing, they cannot be detected from the outside, and if they are brought into a room where confidential information is handled, there is a risk of information leaks, so it is necessary to discover and identify the owner.

[0011] Fig. 1 is a schematic diagram showing how a terminal holder detection system according to this embodiment is installed and operated. Fig. 1 is a schematic diagram of a highly confidential room 1, which is an example of a monitored space. As an example, there are three people in room 1, including person 40 who has a transmitting terminal 41, such as a smartphone, hidden in his or her clothing, and people 50 and 60 who do not have a transmitting terminal. The purpose of the terminal holder detection system in this example is to detect person 40 who is carrying transmitting terminal 41.

[0012] 1, room 1 is surrounded by walls 23, 24, 25, and 28 (not shown), and is further divided by floor 21 and ceiling 22. There are also windows 27 and doors 26. The walls and other components are made of common building materials, and are not perfect radio wave absorbers, but rather have the property of reflecting radio waves at least to a certain degree. Although not shown, room 1 is assumed to be equipped with appropriate desks and chairs, as well as safes and lockable cabinets for storing important items such as documents and recording media containing confidential information. The above-mentioned structural information about the interior of room 1 is assumed to be known and expressed in the world coordinate system, and is stored in the memory unit of the system main unit.

[0013] The room 1 is equipped with a position detection device 200. The position detection device 200 is a means for detecting the positions (coordinate values) of people (people 40, 50, and 60 in FIG. 1) and objects other than people present in the room 1, expressed in a world coordinate system defined in the room 1. The detection results by the position detection device 200 are used as information for calculating the theoretical value of the radio waves received by the receiving device. The detection results by the position detection device 200 are temporarily stored in the storage device 111 and are read out and referenced as appropriate. The position detection device 200 can be realized by a laser radar type distance sensor. Alternatively, it may be an image sensor (camera) equipped with image processing means, or pressure sensors may be installed all over the surface under the floor surface 21 to detect the position from the weight of a person.

[0014] The receiving device 300 is an antenna device installed on the ceiling surface 22 of the room 1 for receiving radio waves. The receiving device 300 is configured as an antenna array, and is configured to be able to detect not only the reception strength of the radio waves transmitted from the transmitting terminal 41, but also the direction of arrival of the radio waves. The receiving device 300 is realized by well-known technology as appropriate, and therefore a detailed description thereof will be omitted. The location where the receiving device 300 is installed (coordinate values ​​expressed in a world coordinate system defined in the room 1) is assumed to be stored in advance in the storage device 111.

[0015] Fig. 2 shows a bird's-eye view of the room 1 shown in Fig. 1 looking down from the ceiling to the floor, and a coordinate system that defines the direction from which radio waves arrive at the receiving device 300. In Fig. 2 looking down on the room 1, the coordinate system is defined so that the downward direction of the drawing is 0 degrees and the angle increases clockwise. Note that the receiving device 300 is not installed so that there are no gaps in the wall surface, but some gaps exist, so that radio waves, although weak in intensity, also arrive from the direction of the wall surface.

[0016] Figure 3 shows a block diagram of a terminal holder detection system according to the present invention. The terminal holder detection system 10 is composed of a system main unit 100 in addition to the receiving device 300 and position detection device 200 already explained. Note that the communication means connecting these devices can be realized by a wired method conforming to standards such as Ethernet (registered trademark), RS232C, or RS485, or a wireless method using Wi-Fi (registered trademark), Bluetooth (registered trademark), or the like, and therefore a description thereof will be omitted. Furthermore, descriptions of components that can be realized by well-known technologies will be simplified or omitted as appropriate.

[0017] The system main unit 100 includes a control unit 110 and a storage device 111. The control unit 110 includes a processor such as a CPU (Central Processing Unit) or an MPU (Micro-Processing Unit). The storage device 111 is a storage means realized by known means such as a magnetic medium such as a HDD or a semiconductor memory. In addition to the program that controls the overall operation of the system main unit 100, it stores the program modules that configure each part of the system main unit 100, parameters such as thresholds, an area for temporarily storing data during processing, structural information 112, and a human model 113. The stored information is exchanged between each part of the control device 110 as appropriate.

[0018] The processor of the control device 110 executes the program modules stored in the memory device 111 to realize the functions of the model generation unit 115, propagation information calculation unit 120, theoretical value buffer 140, actual measurement value spectrum calculation unit 145, actual measurement value buffer 150, comparison and determination unit 160, and output unit 170 of the system main unit 100, which will be described below.

[0019] Based on the received signal received by the array antenna of the receiving device 300, the actual measurement value spectrum calculation unit 145 calculates the actual measurement value of the angular spectrum, which is the distribution of the received strength of the radio waves for each direction from which the radio waves arrive. 4 is a diagram showing an example of the angular spectrum of radio waves received by the receiving device 300. The angular spectrum represents the distribution of reception strength, in which the strength of radio waves arriving from each angle is arranged, with a predetermined reference direction as seen from the antenna 3 being set at 0°.

[0020] The angular spectrum can be calculated using the well-known Beamformer method, MUSIC (Multiple Signal Classification) method, etc. These methods are described, for example, in "Institute of Electronics, Information and Communication Engineers, Knowledge Base, Knowledge Forest, 4th Group, Part 2, Chapter 8, 8-4, Direction of Arrival Estimation" (http: / / www.ieice-hbkb.org / files / 04 / 04gun_02hen_08.pdf#page=11).

[0021] See Figure 3. Actual measurement value buffer 150 is a buffer that temporarily stores the actual measurement values ​​of the angular spectrum calculated by actual measurement value spectrum calculation unit 145 together with time information. It can be realized using a semiconductor memory or a magnetic disk as appropriate, but it may also be realized by allocating a certain area in storage device 111 and integrating it with storage device 111 rather than as an independent element.

[0022] The structural information 112 is information about the elements that define the room 1, and is used to find the theoretical value of the reception strength of each receiving device. For example, the structural information 112 may define a coordinate system (world coordinate system) with the corner of the floor 21 as its origin, and may include geometric information such as the sizes and positions of the walls 23 to 25, 28, the ceiling 22, the floor 21, the windows 27, the doors 26, and fixtures (not shown), mathematical formula information defining the shapes of the surfaces of the walls and the like, surface material information, radio wave reflectivity, and the like, expressed using a modeling method such as BIM (Building Information Model).

[0023] Person model 113 is information that represents the three-dimensional shape of a person who may exist in room 1 using a polygon model, surface model, or the like, and is a model that represents at least the height (170 cm) and width (60 cm) of a standard human physique. Person model 113 has a reflectivity of radio waves on its body surface.

[0024] The model generation unit 115 refers to the structural information 112, virtually places a person model 113 at the position detected by the position detection device 200 for each person present in the room 1, generates a detection model that models the positional relationship of moving people inside the room 1, and outputs the detection model to the propagation information calculation unit 120.

[0025] The propagation information calculation unit 120 calculates theoretical values ​​of the path along which the radio wave transmitted from the transmitting terminal 41 can propagate to each receiving device and the strength at which the radio wave is received. To this end, the propagation information calculation unit 120 has a path information calculation unit 125 and a theoretical reception strength calculation unit 130. The path information calculation unit 125 appropriately references the detection model generated by the model generation unit 115, the structural information 112 stored in the storage device 111, and the person model 113, and sequentially sets each person present in the room 1 as a candidate, assuming that they are carrying the transmitting terminal 41, and calculates the propagation path of the radio waves from their nearby positions, taking into account reflections on wall surfaces, obstructions by other people, etc. The calculation of the propagation path is performed based on a method similar to the ray tracing method well known in the field of computer graphics. This will be explained with reference to FIG. 2.

[0026] 2, assuming that person 40 is a candidate who carries transmitting terminal 41, dashed line 400 and dashed lines 401 and 402 are shown extending from transmitting terminal 41 to its periphery. These dashed line 400 and dashed lines 401 and 402 are calculated as paths (propagation paths) along which radio waves transmitted from transmitting terminal 41 can propagate. These propagation paths can be considered in three dimensions in various directions with transmitting terminal 41 at the center, but for simplicity, the present embodiment will be described assuming propagation paths in a plane viewed from above as shown in FIG.

[0027] The dashed-dotted line 400 indicates the propagation path of the direct wave that reaches the receiving device 300 directly from the transmitting terminal 41, and the dashed lines 401 and 402 indicate the propagation paths of the indirect waves that reach the receiving device 300 after being reflected by the wall surfaces 24 and 28, respectively. The path information calculation unit 125 refers to the detection model generated by the model generation unit 115 and the structural information 112 stored in the storage device 111, and calculates a propagation path to each receiving device by imaginarily considering straight lines called "rays" in each direction from the transmitting terminal 41 and taking into account reflections on walls, ceilings, etc. This is based on a method called the ray tracing method.

[0028] The path information calculation unit 125 determines the length of the ray, i.e., the maximum distance that the radio wave can propagate, by setting an upper limit on the number of times that the radio wave can be reflected from a wall. For example, the maximum number of times that the radio wave can be reflected is set to five. In Fig. 2, for simplicity, three rays are shown, and the maximum distance of each ray is not shown. In the processing described below, the angular resolution of the rays affects the calculation of theoretical values, so it is determined by taking into consideration the balance between the processing speed and the required accuracy of estimating the position of the transmitting terminal 41. For example, rays can be considered every three degrees.

[0029] In Figure 1, it is explained that person 40 is carrying transmitting terminal 41, but in reality it is unknown which person is carrying it, so route information calculation unit 125 similarly calculates rays as the propagation path of radio waves when person 50 is carrying it and when person 60 is carrying it, and outputs this information to reception strength theoretical value calculation unit 130.

[0030] The theoretical reception strength calculation unit 130 sequentially selects the persons 40, 50, and 60 detected by the position detection device 200 as candidates for carrying the transmitting terminal 41, and calculates the theoretical value of the angular spectrum of the radio waves when they are transmitted from the positions of the candidates and received at the position of the receiving device 300, based on the information on the propagation path calculated by the path information calculation unit 125. Figures 5(a) to 5(c) are diagrams showing examples of the theoretical values ​​of the angular spectrum when radio waves transmitted from the positions of the persons 40, 50, and 60, respectively, are received at the position of the receiving device 300.

[0031] See Figure 3. The theoretical value buffer 140 is a buffer that temporarily stores the theoretical value of the angular spectrum calculated for each person by the theoretical reception intensity value calculation unit 130 together with time information. This can be realized using a semiconductor memory or a magnetic disk as appropriate, but it may also be realized by allocating a certain area in the storage device 111 and integrating it with the storage device 111 rather than as an independent element. The comparison and determination unit 160 compares the theoretical values ​​of the angular spectrum stored in the theoretical value buffer 140 with the actual measured values ​​of the angular spectrum stored in the actual measured value buffer 150 for each of a plurality of persons (persons 40, 50, and 60 in the example of FIG. 1), and calculates a similarity that represents the degree of similarity between the theoretical values ​​and the actual measured values. As the similarity, a normalized correlation such as a cosine similarity may be calculated.

[0032] The comparison and determination unit 160 determines that the person whose theoretical value of the angular spectrum is most similar to the measured value of the angular spectrum received by the receiving device 300 is the person who owns the transmitting terminal 41, among the plurality of people. The output unit 170 is composed of an I / F circuit and its control program that transmits to the outside the information about the owner of the transmitting terminal 41 output from the comparison and determination unit 160. If a monitor is displayed externally, a floor plan such as the overhead view in Fig. 2 may be displayed on the screen, and the owner may be colored to distinguish them from other people.

[0033] Alternatively, if it is determined that the transmitting terminal 41 has been brought in, processing such as turning on a lighting device on the monitoring device or issuing an audio alert may be performed so that security guards waiting at the security center can recognize it. Furthermore, a voice message may be played to the person carrying the transmitting terminal 41 to instruct them not to bring the terminal into the room, as this could lead to information leakage, and to store the valuables in a locker outside the room.

[0034] In this way, by comparing the theoretical values ​​of the angular spectrum calculated for each of a plurality of persons with the actual measured values ​​of the angular spectrum, it becomes possible to determine which of the plurality of persons is carrying the transmitting terminal 41. Note that the angular spectrum in the above description includes the spectrum of the direct wave component and the spectrum of the indirect wave component. In the following description, radio waves that include both direct waves and indirect waves may be referred to as "composite waves."

[0035] In addition, the actual measured value of the angular spectrum including both the direct wave and the indirect wave shown in Figure 4 may be referred to as the "first actual measured value," and the theoretical value of the angular spectrum including both the direct wave and the indirect wave shown in Figures 5(a) to 5(c) may be referred to as the "first theoretical value." In addition, the method of calculating the similarity by comparing the first actual measurement value and the first theoretical value of the angular spectrum, and detecting the person for whom the first theoretical value of the angular spectrum that is most similar to the first actual measurement value is calculated, as the holder of the transmitting terminal 41, may be referred to as the "first detection method."

[0036] In the above-mentioned first actual measurement value and first theoretical value, if the transmitting terminal 41 and the receiving device 300 are in a line-of-sight state (for example, a state in which there is no obstruction between the transmitting terminal 41 and the receiving device 300 due to an obstacle or the like), the intensity of the direct wave component is generally higher than the intensity of the indirect wave component. Therefore, the influence of the direct wave on the entire angular spectrum becomes dominant. Because the influence of the direct wave on the angular spectrum is dominant, the detection accuracy of detecting the carrier of the transmitting terminal 41 by the first detection method may decrease.

[0037] An example of a scene in which the detection accuracy of the person carrying the transmitting terminal 41 may be reduced due to the influence of direct waves will be described with reference to Fig. 6. Fig. 6 is a bird's-eye view of an example of a situation in which multiple people 40 and 50 are located in the same direction as seen from the receiving device 300. In this figure, it is assumed that the transmitting terminal 41 and the receiving device 300 are in line of sight. In such a case, the direction of arrival of the direct wave transmitted from the position of person 40 and the direction of arrival of the direct wave transmitted from the position of person 50 are the same and become dominant components, so the theoretical value of the angular spectrum calculated for person 40 and the theoretical value of the angular spectrum calculated for person 50 will be similar. For this reason, it may become impossible to distinguish whether person 40 or person 50 is the owner of transmitting terminal 41.

[0038] Therefore, the actual measurement value spectrum calculation unit 145 calculates an actual measurement value of the angular spectrum of the indirect wave component of the radio wave received by the receiving device 300. In the following description, the actual measurement value of the angular spectrum of the indirect wave component of the radio wave received by the receiving device 300 may be referred to as a "second actual measurement value." A method for calculating the second actual measurement value will be described later. Furthermore, the theoretical reception strength calculation unit 130 calculates, for each of the plurality of people (persons 40, 50, and 60 in the example of FIG. 6), a theoretical value of the reception strength when only the indirect waves of the radio waves transmitted from the respective positions of the plurality of people are received at the position of the receiving device 300. In the following description, the theoretical value of the reception strength when only the indirect waves of the radio waves transmitted from the respective positions of the plurality of people are received at the position of the receiving device 300 may be referred to as a "second theoretical value."

[0039] The comparison and determination unit 160 compares the second actual measurement value of the angular spectrum with the second theoretical value (i.e., the actual measurement value and theoretical value of the angular spectrum of the indirect wave) to calculate the similarity, and detects the person for whom the calculated second theoretical value of the angular spectrum is most similar to the second actual measurement value as the owner of the transmitting terminal 41. In the following description, the method of comparing the second actual measurement value of the angular spectrum with the second theoretical value to calculate the similarity and detecting the person for whom the calculated second theoretical value of the angular spectrum is most similar to the second actual measurement value as the owner of the transmitting terminal 41 may be referred to as the "second detection method."

[0040] Fig. 7 is a diagram showing an example of actual measurement values ​​(second actual measurement values) of the angular spectrum of the indirect wave of the radio wave received by the receiving device 300. Fig. 8(a) to Fig. 8(c) are diagrams showing an example of theoretical values ​​(second theoretical values) of the angular spectrum when the indirect wave of the radio wave transmitted from the positions of the persons 40, 50, and 60, respectively, is received at the position of the receiving device 300. Even if the persons 40 and 50 are located in the same direction as seen from the receiving device 300, the second theoretical value of the angular spectrum of the person 40 shown in Fig. 8(a) deviates from the second theoretical value of the angular spectrum of the person 50 shown in Fig. 8(b). Therefore, it can be accurately detected that the person 40 whose calculated second theoretical value is close to the second actual measurement value is carrying the transmitting terminal 41.

[0041] According to the second detection method, the influence of the direct wave on the second actual measured value and the second theoretical value of the angular spectrum can be eliminated, thereby preventing a decrease in the detection accuracy of detecting the holder of the transmitting terminal 41 due to the dominance of the influence of the direct wave on the angular spectrum. Therefore, for example, the comparison and determination unit 160 may detect the holder of the transmitting terminal 41 using the second detection method when multiple people are located in the same direction as seen from the receiving device 300, and may detect the holder of the transmitting terminal 41 using the first detection method when multiple people are not located in the same direction as seen from the receiving device 300.

[0042] For example, the comparison and determination unit 160 may determine whether multiple people are located in the same direction as seen from the receiving device 300, based on the detection result of the person's position by the position detection device 200. In other words, the comparison and determination unit 160 may determine, based on the positional relationship of the multiple people detected by the position detection device 200, whether to detect the person carrying the transmitting terminal 41 by the first detection method or the second detection method.

[0043] Furthermore, when multiple people are located in the same direction as seen from the receiving device 300, the similarities between the first actual measurement values ​​and the first theoretical values ​​are close to each other among these multiple people. Therefore, when the similarities between the first actual measurement values ​​and the first theoretical values ​​are different among multiple people present in the monitored space 1, it may be determined that multiple people are not located in the same direction as seen from the receiving device 300, and the holder of the transmitting terminal 41 may be detected by the first detection method. On the other hand, when the similarities between the first actual measurement values ​​and the first theoretical values ​​are close to each other among the multiple people present in the monitored space 1, the holder of the transmitting terminal 41 may be detected by the second detection method.

[0044] Next, an example of a method for acquiring the actual measurement value (that is, the second actual measurement value) of the angular spectrum of the indirect wave component of the radio wave received by the receiving device 300 will be described. (First example of how to obtain the second measured value of the angular spectrum) 6, first, the actual measurement value spectrum calculation unit 145 acquires the angle of arrival θ (direction of arrival) of the direct wave arriving at the receiving device 300 from the transmitting terminal 41. For example, the actual measurement value spectrum calculation unit 145 may acquire, as the angle of arrival θ of the direct wave, the azimuth angle at which the angular spectrum of the radio wave, including the direct wave, received by the receiving device 300, reaches its peak value.

[0045] The actual measurement value spectrum calculation unit 145 generates a theoretical value of the reception intensity of the direct wave arriving at each element antenna of the array antenna of the receiving device 300 from the direction of the arrival angle θ (hereinafter sometimes referred to as the “theoretical value of the direct wave component”). The actual measurement value spectrum calculation unit 145 calculates the reception strength of the indirect wave by subtracting the theoretical value of the direct wave component from the actual measurement value of the reception strength of the radio waves (i.e., the composite wave) received by each element antenna, and converts the reception strength of the indirect wave of each element antenna into an angular spectrum to obtain the actual measurement value (second actual measurement value) of the angular spectrum of the indirect wave component.

[0046] 9(a) to 9(d) are explanatory diagrams of an example of a method for calculating the second measured value of the angular spectrum of an indirect wave. Although Fig. 9(a) to Fig. 9(c) show an example in which the array antenna has four element antennas (first element antenna to fourth element antenna), the number of element antennas may be other than four. Wc1 to Wc4 in Figure 9(a) show time series data of the actual measured values ​​of the receiving strength of the first element antenna to the fourth element antenna, and Wd1 to Wd4 in Figure 9(b) show time series data of the theoretical values ​​of the direct wave components of the radio waves arriving at the first element antenna to the fourth element antenna.

[0047] The phase difference between the element antennas for the direct wave component theoretical values ​​Wd1 to Wd4 is set according to the direct wave arrival angle θ. In the following description, data obtained by combining time series data for multiple direct wave component theoretical values ​​Wd1 to Wd4 generated for each of multiple element antennas of the array antenna of one receiving device 300 may be referred to as "time series data for a set of direct wave component theoretical values."

[0048] 9(c), the actual measurement value spectrum calculation unit 145 calculates time series data of the reception intensities Wi1 to Wi4 of the indirect waves received by the first to fourth element antennas by subtracting time series data of the direct wave component theoretical values ​​Wd1 to Wd4 from time series data of the actual measurement values ​​Wc1 to Wc4, respectively. The actual measurement value spectrum calculation unit 145 converts the time series data of the reception intensities Wi1 to Wi4 into an angular spectrum to obtain the actual measurement value (second actual measurement value) of the angular spectrum of the indirect wave component shown in FIG. 9(d).

[0049] However, when calculating the theoretical value of the direct wave component, the phase and amplitude of the direct wave arriving at the receiving device 300 from the transmitting terminal 41 are unknown. For this reason, the actual measurement value spectrum calculation section 145 prepares a plurality of sets of time-series data of the direct wave component theoretical values ​​Wd1 to Wd4, each having a plurality of different combinations of phase and amplitude, which are obtained by changing the overall phase and amplitude of each of the time-series data of a set of the direct wave component theoretical values ​​Wd1 to Wd4. For example, 18×20=360 sets of time-series data of the direct wave component theoretical values ​​Wd1 to Wd4, each having 18 different phases and 20 different amplitudes, may be prepared by shifting the overall phase of each of the time-series data of a set of the direct wave component theoretical values ​​Wd1 to Wd4 by 10 degrees.

[0050] Furthermore, for example, time series data of a plurality of sets of direct wave component theoretical values ​​Wd1 to Wd4 in which the phase difference between the element channels is shifted within one set of direct wave component theoretical values ​​Wd1 to Wd4 may be prepared in consideration of an error when the actual measurement value spectrum calculation unit 145 acquires the arrival angle θ of the direct wave. The magnitude ε by which the phase difference between the element channels of the direct wave component theoretical values ​​Wd1 to Wd4 is shifted may be determined, for example, according to the accuracy when the actual measurement value spectrum calculation unit 145 acquires the arrival angle θ. For example, 18×20×3=1080 sets of time series data of the direct wave component theoretical values ​​Wd1 to Wd4 may be prepared, each set having 18 different phases obtained by shifting the overall phase of the time series data of the direct wave component theoretical values ​​Wd1 to Wd4, 20 different amplitudes, and three different phase differences between the element channels (for example, θ−ε, θ, θ+ε).

[0051] The actual measurement value spectrum calculation unit 145 calculates time series data of multiple sets of reception intensities Wi1 to Wi4 of indirect waves by subtracting time series data of multiple sets of theoretical values ​​Wd1 to Wd4 of direct wave components from time series data of actual measurement values ​​Wc1 to Wc4. Then, the time series data of multiple sets of reception intensities Wi1 to Wi4 of indirect waves is converted into angular spectra, thereby acquiring actual measurement values ​​(second actual measurement values) of the angular spectra of multiple indirect wave components.

[0052] For example, if 1080 sets of direct wave component theoretical values ​​Wd1 to Wd4 are prepared, 1080 sets of indirect wave reception intensities Wi1 to Wi4 are calculated by subtracting the 1080 sets of direct wave component theoretical values ​​Wd1 to Wd4 from the actual measurement values ​​Wc1 to Wc4, respectively, to obtain 1080 second actual measurement values. In the following description, the plurality of second measured values ​​of the angular spectrum (1080 in the above example) acquired for a single angle of arrival θ will be referred to as a "group of second measured values ​​of the angular spectrum."

[0053] The comparison determination section 160 compares the plurality of second actual measured values ​​with the second theoretical value for each person, and calculates the similarity between the plurality of second actual measured values ​​and the second theoretical value for each person. 9(a) to 9(d), the comparison and determination unit 160 compares each of the second actual measurement values ​​S1, S2, S3, S4, S5, ... of the angular spectrum of the indirect wave with the second theoretical value Sa of one of the plurality of persons (person 40 in the example of FIG. 6), and calculates a plurality of similarities (i.e., the similarity between the second actual measurement value S1 and the second theoretical value Sa, the similarity between the second actual measurement value S2 and the second theoretical value Sa, the similarity between the second actual measurement value S3 and the second theoretical value Sa, the similarity between the second actual measurement value S4 and the second theoretical value Sa, the similarity between the second actual measurement value S5 and the second theoretical value Sa, ...).

[0054] The comparison and determination section 160 calculates a frequency distribution (histogram) Ha of the similarities between the second measured values ​​S1, S2, S3, S4, S5 . . . of the group of angular spectra and the second theoretical values ​​Sa. Similarly, the comparison determination unit 160 calculates the second theoretical values ​​Sb, Sc of other persons (persons 50 and 60 in the example of FIG. 6) and the frequency distributions Hb, Hc of the similarities between the second measured values ​​S1, S2, S3, S4, S5... of the group of angular spectra and the second theoretical value Sa.

[0055] The comparison determination unit 160 calculates the average value of a predetermined percentage of the top similarities in the frequency distributions Ha, Hb, Hc as the similarities between the second theoretical values ​​Sa, Sb, and Sc and the second measured values ​​S1, S2, S3, S4, S5, ... of the group of angular spectra, respectively. The comparison determination unit 160 detects, among a plurality of persons (persons 40, 50, and 60 in the example of FIG. 6), person 40 for whom the second theoretical value Sa was calculated to be most similar to the group of second actual measurement values ​​S1, S2, S3, S4, S5, ... of the angular spectrum, as the owner of the transmitting terminal 41.

[0056] (Second example of how to obtain the second measured value of the angular spectrum) As an example of another method for obtaining the second measured value of the angular spectrum, the receiving device 300 may control the directivity of the antenna so as to make it difficult to receive a direct wave. For example, the receiving device 300 obtains the arrival angle θ of the direct wave based on the azimuth angle at which the angular spectrum of the radio wave, including the direct wave, received by the receiving device 300 reaches a peak value. The directivity of the antenna is controlled so that the reception sensitivity of the radio wave arriving from the arrival angle θ decreases and the reception sensitivity of the radio wave arriving from directions other than the arrival angle θ increases. For example, the directivity of the antenna may be controlled so that the reception sensitivity of the radio wave arriving from the arrival angle θ is minimized and the reception sensitivity of the radio wave arriving from directions other than the arrival angle θ is maximized. This makes it possible to minimize the reception strength of the direct wave component and maximize the reception strength of the indirect wave component.

[0057] Next, with reference to Figures 11(a) and 11(b), another example of a scene in which the detection accuracy of the person carrying the transmitting terminal 41 may be reduced due to the influence of direct waves will be described. Figure 11(a) shows a scene in which the receiving device 300 is occluded from direct waves by an obstacle other than the person 40 carrying the transmitting terminal 41 (person 50 in the example of Figure 11(a)). In other words, the transmitting terminal 41 and the receiving device 300 are not in line of sight. Note that the obstacle blocking the receiving device 300 from direct waves may be an object other than a person. Figure 11(b) shows a scene in which the receiving device 300 is occluded from direct waves by the person 40 carrying the transmitting terminal 41.

[0058] If the receiving device 300 is shielded from direct waves, various angular spectra are observed depending on the degree of shielding, and there is a risk that an unrelated person may be mistakenly detected as the carrier. Therefore, the comparison and determination unit 160 may detect the holder of the transmitting terminal 41 using the first detection method when there is no risk that the receiving device 300 is shielded from direct waves, and may detect the holder of the transmitting terminal 41 using the second detection method when there is a risk that the receiving device 300 is shielded from direct waves.

[0059] For example, the comparison and determination unit 160 may determine whether or not there is a risk that the receiving device 300 is shielded from direct waves, based on the positional relationship of a person or object detected by the position detection device 200. That is, the comparison and determination unit 160 may determine whether to detect the holder of the transmitting terminal 41 by the first detection method or the second detection method, based on the positional relationship of a person or object detected by the position detection device 200.

[0060] For example, the comparison and determination unit 160 may detect the holder of the transmitting terminal 41 using the second detection method when an obstacle (person 50 in the example of Figure 11(a)) is present near (including on) the line segment connecting one of multiple people (persons 40, 50, and 60 in the example of Figure 11(a)) (person 40 in the example of Figure 11(a)) and the receiving device 300, and may detect the holder of the transmitting terminal 41 using the first detection method when no obstacle is present near any of the line segments connecting each of the multiple people and the receiving device 20.

[0061] Furthermore, when the receiving device 300 is shielded from direct waves, the degree of time fluctuation of the reception intensity at the receiving device 300 increases. For example, the degree of time fluctuation of the shape of the angular spectrum increases. For this reason, for example, the comparison and determination unit 160 may determine whether the degree of time fluctuation of the reception strength or the shape of the angular spectrum of the radio waves including the direct wave received by the receiving device 300 is greater than a threshold. If the degree of time fluctuation is greater than the threshold, the carrier of the transmitting terminal 41 may be detected by the second detection method, and if the degree of time fluctuation is equal to or less than the threshold, the carrier of the transmitting terminal 41 may be detected by the first detection method.

[0062] If the receiving device 300 is shielded from the direct wave, the angle (azimuth) at which the peak value of the angular spectrum appears changes depending on the degree of shielding. Therefore, it is difficult to obtain the arrival angle θ of the direct wave from the angle at which the peak value of the angular spectrum appears, as in the above-described method of obtaining the second actual measurement value. It is not possible to uniquely determine the second actual measurement value of a group of angular spectra based on a single arrival angle θ.

[0063] Therefore, the actual measurement value spectrum calculation unit 145 assumes that radio waves are being emitted from the positions of multiple people (persons 40, 50, and 60 in the example of Figure 11(a) or Figure 11(b)), and calculates a group of second actual measurement values ​​of the angular spectrum for each of the multiple people. The comparison and determination unit 160 compares the second actual measurement values ​​of the group of angular spectra calculated for each of the plurality of people with the second theoretical value of the angular spectrum calculated for each of the plurality of people, thereby calculating the similarity between the second actual measurement values ​​of the group of angular spectra and the second theoretical value of the angular spectrum for each of the plurality of people, and then detects the person for whom the highest similarity is calculated as the owner of the transmitting terminal 41.

[0064] When calculating the second actual measurement values ​​of the group of angular spectra, the actual measurement value spectrum calculation unit 145 assumes the azimuth angles of the multiple people as seen from the receiving device 300 as candidates for the arrival angle θ of the direct wave, based on the person position detection results obtained by the position detection device 200. Hereinafter, the assumed arrival angles for the people 40, 50, and 60 will be referred to as "θa," "θb," and "θc," respectively.

[0065] Based on these arrival angles, the actual measurement value spectrum calculation unit 145 generates time-series data of a set of direct wave component theoretical values ​​Wd1-Wd4 ( FIG. 9( b) ) for calculating a set of second actual measurement values ​​of angular spectra for each of the multiple people. For example, it generates time-series data of a set of direct wave component theoretical values ​​Wd1-Wd4 for person 40 based on arrival angle θa, generates time-series data of a set of direct wave component theoretical values ​​Wd1-Wd4 for person 50 based on arrival angle θb, and generates time-series data of a set of direct wave component theoretical values ​​Wd1-Wd4 for person 60 based on arrival angle θc. In this case, the magnitude ε by which the phase difference between the element channels of the direct wave component theoretical values ​​Wd1-Wd4 may be determined depending on, for example, the accuracy of position detection of a person or object by the position detection device 200.

[0066] Then, by subtracting each of the time series data of the set of direct wave component theoretical values ​​Wd1 to Wd4 generated for each of the multiple people from the time series data of the actual measurement values ​​Wc1 to Wc4 (Figure 9(a)), time series data of the indirect wave receiving intensities Wi1 to Wi4 (Figure 9(c)) are calculated for each of the multiple people. The actual measurement value spectrum calculation unit 145 converts the time series data of the reception intensities Wi1 to Wi4 of the indirect waves calculated for each of the plurality of people into angular spectra, thereby calculating a group of second actual measurement values ​​of the angular spectra for each of the plurality of people.

[0067] Furthermore, when controlling the directivity of the receiving device 300 to obtain the second actual measured value of the angular spectrum (the second example of the method for obtaining the second actual measured value of the angular spectrum described above), the azimuth angles of multiple people as seen from the receiving device 300 may be assumed as candidates for the arrival angle θ of the direct wave based on the person position detection results by the position detection device 200, and the directivity of the antenna may be controlled so that the reception sensitivity of radio waves arriving from each of these arrival angles θ decreases and the reception sensitivity of radio waves arriving from directions other than the arrival angle θ increases, thereby obtaining the second actual measured value of the angular spectrum for each of the multiple people.

[0068] In the above description, when a plurality of people are positioned in the same direction as seen from receiving device 300, a group of second measured values ​​of the angular spectrum is obtained based on a single angle of arrival θ. Alternatively, even when multiple people are positioned in the same direction as seen from receiving device 300, a group of second actual measured values ​​of angular spectra may be obtained for each of the multiple people, and the second actual measured values ​​of angular spectra obtained for each of the multiple people may be compared with the second theoretical values ​​of angular spectra calculated for each of the multiple people, thereby calculating the similarity between the second actual measured values ​​of the group of angular spectra and the second theoretical values ​​of angular spectra for each of the multiple people.

[0069] Furthermore, even when multiple people are located in the same direction as seen from the receiving device 300, when controlling the directivity of the receiving device 300 to obtain the second measured value of the angular spectrum, the azimuth angles of the multiple people as seen from the receiving device 300 may be assumed as candidates for the arrival angle θ of the direct wave based on the person position detection results by the position detection device 200, and the directivity of the antenna may be controlled so that the reception sensitivity of radio waves arriving from each of these arrival angles θ decreases and the reception sensitivity of radio waves arriving from directions other than the arrival angle θ increases, thereby obtaining the second measured value of the angular spectrum for each of the multiple people.

[0070] (operation) FIG. 12 is a flowchart illustrating an example of a terminal owner detection method according to the embodiment. In step S1, the position detection device 200 detects the positions of objects and people present in the room 1 in the world coordinate system and transmits the detected positions to the propagation information calculation unit 120 of the system main unit 100. In step S2, the model generation unit 115 refers to the structural information 112 and the person model 113 stored in the storage device 111, creates a detection model from the position of each person in the room 1 measured by the position detection device 200 in step S1, and outputs the detection model to the propagation information calculation unit 120.

[0071] In step S3, the comparison and determination unit 160 determines whether to detect the holder of the transmitting terminal 41 using the first detection method or the second detection method. For example, it may determine that detection should be performed using the first detection method if there are no multiple people in the same direction as seen from the receiving device 300 and the receiving device 300 is not shielded from direct waves, and it may determine that detection should be performed using the second detection method if there are multiple people in the same direction as seen from the receiving device 300 or the receiving device 300 is shielded from direct waves. If detection should be performed using the first detection method (step S4: Y), the process proceeds to step S5. If detection should be performed using the second detection method (step S4: N), the process proceeds to step S8.

[0072] In step S5, the actual measurement value spectrum calculation unit 145 calculates an actual measurement value (i.e., a first actual measurement value) of the angular spectrum of the composite wave including both the direct wave component and the indirect wave component, based on the received signal received by the receiving device 300. In step S6, the theoretical reception intensity calculation unit 130 sequentially selects the people detected by the position detection device 200 as candidates who possess the transmitting terminal, and calculates the theoretical value (i.e., the first theoretical value) of the angular spectrum of the composite wave when radio waves transmitted from the position of the candidate are received at the position of the receiving device 300.

[0073] In step S7, the theoretical reception strength calculation unit 130 compares the first theoretical value with the first actual measurement value for each person detected by the position detection device 200, calculates the similarity between the first theoretical value and the first actual measurement value, and determines that the person with the highest calculated similarity is carrying the transmitting terminal. Then, the process proceeds to step S11. On the other hand, in step S8, the actual measurement value spectrum calculation unit 145 calculates an actual measurement value of the angular spectrum including only the indirect wave component of the radio wave received by the receiving device 300 (that is, a second actual measurement value). In step S9, the theoretical reception intensity calculation unit 130 sequentially selects the people detected by the position detection device 200 as candidates who possess the transmitting terminal, and calculates the theoretical value (i.e., the second theoretical value) of the angular spectrum of only the indirect waves when radio waves transmitted from the position of the candidate are received at the position of the receiving device 300.

[0074] In step S10, the theoretical reception strength value calculation unit 130 compares the second theoretical value with the second actual measurement value for each person detected by the position detection device 200, calculates the similarity between the second theoretical value and the second actual measurement value, and determines that the person with the highest calculated similarity is carrying the transmitting terminal. Then, the process proceeds to step S11. In step S11, the output unit 170 outputs to the outside the information about the owner of the transmitting terminal input from the comparison and determination unit 160. As already mentioned, an external device (not shown) performs a notification process to alert the owner of the transmitting terminal, and then the process ends.

[0075] (Effects of the embodiment) (1) The terminal holder detection device includes a receiving unit 300 that receives radio waves from a transmitting terminal present within the monitored space, a position detection unit 200 that detects the positions of multiple people present within the monitored space, a memory unit 111 that pre-stores structural information indicating the reflectivity of radio waves and spatial structure information at various locations within the monitored space, a propagation information calculation unit 120 that calculates, for each of the multiple people, a theoretical value of the reception strength when the indirect wave of the radio waves transmitted from the position of each of the multiple people is received at the position of the receiving unit 300 based on the structural information and the position information of the people, and a comparison and determination unit 160 that compares the actual measurement value and theoretical value of the reception strength of the indirect wave component of the radio waves transmitted from the transmitting terminal among the multiple people and determines which person is carrying the transmitting terminal. This prevents a decrease in the accuracy of detecting the carrier of the transmitting terminal, which is caused by the dominant effect of the direct wave on the angular spectrum, and as a result, improves the accuracy of detecting the position of the carrier of the transmitting terminal from the angular spectrum of the received signal strength.

[0076] (2) The terminal carrier detection device may include an actual measurement value calculation unit that calculates multiple candidates for the actual measurement value of the reception strength of the indirect wave component by subtracting multiple different direct wave component theoretical values ​​that are generated in advance as theoretical values ​​of the reception strength of the direct wave component of the radio waves arriving at the reception unit 300 from the transmitting terminal from the reception strength of the radio waves received by the reception unit 300. The comparison and determination unit 160 may determine that the person whose calculated theoretical value is most similar to the multiple candidates is the person who carries the transmitting terminal. As a result, the actual measurement value of the reception intensity of the indirect wave component of the radio wave received by the receiving unit 300 can be obtained.

[0077] (3) The directivity of the receiving unit 300 may be controlled so that the receiving strength of the direct wave component arriving at the receiving unit 300 from the transmitting terminal decreases and the receiving strength of the indirect wave component increases, thereby obtaining an actual measurement value of the receiving strength of the indirect wave component. As a result, the actual measurement value of the reception intensity of the indirect wave component of the radio wave received by the receiving unit 300 can be obtained.

[0078] (4) Based on the structural information and the positional information, the propagation information calculation unit 120 may calculate, as a first theoretical value, the theoretical value of the reception strength when both direct waves and indirect waves of radio waves transmitted from the positions of each of the multiple people are received at the position of the receiving unit 300, and may calculate, as a second theoretical value, the theoretical value of the reception strength when indirect waves of radio waves transmitted from the positions of each of the multiple people are received at the position of the receiving unit 300. The comparison and determination unit 160 may compare a first actual measurement value, which is the actual measurement value of the reception strength of the total of the direct wave component and the indirect wave component of the radio waves received by the receiving unit 300, with a first theoretical value to determine the person carrying the transmitting terminal, and if the first actual measurement value and the first theoretical value are similar between multiple people, may compare a second actual measurement value, which is the actual measurement value of the reception strength of the indirect wave component of the radio waves received by the receiving unit 300, with a second theoretical value to determine the person carrying the transmitting terminal. This makes it possible to prevent a decrease in the detection accuracy of the person carrying the transmitting terminal due to the influence of direct waves when a plurality of people are positioned in the same direction as seen from the receiving unit 300.

[0079] (5) Based on the relative positions of multiple people, the comparison and determination unit 160 may determine whether to determine the person carrying the transmitting terminal by comparing a first actual measurement value, which is the actual measurement value of the reception strength of the total of the direct wave component and the indirect wave component of the radio waves received by the receiving unit 300, with a first theoretical value, or to determine the person carrying the transmitting terminal by comparing a second actual measurement value, which is the actual measurement value of the reception strength of the indirect wave component of the radio waves received by the receiving unit 300, with a second theoretical value. This prevents a decrease in the detection accuracy of the person carrying the transmitting terminal due to the influence of direct waves when multiple people are located in the same direction as seen from the receiving unit 300 or when the receiving unit 300 is shielded from direct waves.

[0080] (6) When an obstacle is present near the line segment connecting any one of the multiple persons to the receiving unit 300, the comparison and determination unit 160 may compare a second actual measurement value, which is the actual measurement value of the reception strength of the indirect wave component of the radio waves received by the receiving unit 300, with a second theoretical value to determine the person carrying the transmitting terminal; when no obstacle is present near any of the line segments connecting each of the multiple persons to the receiving unit 300, the comparison and determination unit 160 may compare a first actual measurement value, which is the actual measurement value of the reception strength of the total of the direct wave component and indirect wave component of the radio waves received by the receiving unit 300, with a first theoretical value to determine the person carrying the transmitting terminal. This makes it possible to prevent a decrease in the accuracy of detecting the owner of the transmitting terminal due to the influence of the direct wave when the receiving unit 300 is shielded from the direct wave.

[0081] (7) Based on the degree of time variation in the actual measurement value of the reception strength of the radio waves received by the receiving unit 300, the comparison and determination unit 160 may determine whether to compare a first actual measurement value, which is the actual measurement value of the reception strength of the total of the direct wave component and the indirect wave component of the radio waves received by the receiving unit 300, with a first theoretical value to determine the person carrying the transmitting terminal, or to compare a second actual measurement value, which is the actual measurement value of the reception strength of the indirect wave component of the radio waves received by the receiving unit 300, with a second theoretical value to determine the person carrying the transmitting terminal. This makes it possible to prevent a decrease in the accuracy of detecting the owner of the transmitting terminal due to the influence of the direct wave when the receiving unit 300 is shielded from the direct wave.

[0082] In the above embodiment, the location where the receiving device 300 is installed is stored in advance in the storage device 111, and the location where the receiving device 300 is installed, the location of each candidate, and the structural information 112 are used to determine the theoretical values ​​(first and second theoretical values) of the reception strength when received at the location of the receiving device 300. However, without being limited to this, the theoretical values ​​of the reception strength may be determined using the location of each candidate and the structural information 112 without storing the location of the receiving device 300 in advance by setting the origin of the world coordinate system defined in room 1 as the location of the receiving device 300. [Explanation of symbols]

[0083] 10...terminal holder detection system, 20...receiving device, 21...floor surface, 22...ceiling surface, 23-25, 28...wall surface, 26...door, 27...window, 40, 50, 60...person, 41...transmitting terminal, 100...system main unit, 110...control device, 111...storage device, 112...structural information, 113...person model, 115...model generation unit, 120...propagation information calculation unit, 125...route information calculation unit, 130...receiving strength theoretical value calculation unit, 140...theoretical value buffer, 145...actual measurement value spectrum calculation unit, 150...actual measurement value buffer, 160...comparison determination unit, 170...output unit, 200...position detection device, 300...receiving device

Claims

1. a receiving unit that receives radio waves from a transmitting terminal present within the monitored space; a position detection unit that detects the positions of a plurality of people present in the monitored space; a storage unit that stores in advance structural information indicating the reflectivity of radio waves and spatial structure information at each location within the monitored space; a propagation information calculation unit that calculates, for each of the plurality of people, a theoretical value of reception intensity when an indirect wave of a radio wave transmitted from the position of each of the plurality of people is received at the position of the receiving unit, based on the structural information and position information of the person; a comparison and determination unit that compares an actual measurement value of the reception strength of the indirect wave component of the radio wave transmitted from the transmitting terminal with the theoretical value and determines a person who carries the transmitting terminal among the plurality of persons; A terminal holder detection device comprising:

2. a measurement value calculation unit that calculates a plurality of candidates for the actual measurement value of the reception strength of the indirect wave component by subtracting a plurality of different direct wave component theoretical values ​​that are generated in advance as theoretical values ​​of the reception strength of the direct wave component of the radio wave arriving at the reception unit from the reception strength of the radio wave received by the reception unit, the comparison determination unit determines that the person for whom the theoretical value most similar to the plurality of candidates is calculated owns the calling terminal.

2. The terminal holder detection device according to claim 1.

3. 2. The terminal holder detection device according to claim 1, characterized in that the directivity of the receiving unit is controlled so that the receiving strength of the direct wave component arriving at the receiving unit from the transmitting terminal decreases and the receiving strength of the indirect wave component increases, thereby obtaining an actual measured value of the receiving strength of the indirect wave component.

4. the propagation information calculation unit calculates, based on the structural information and the position information, a theoretical value of reception strength when both direct waves and indirect waves of radio waves transmitted from the positions of each of the plurality of people are received at the position of the receiving unit, as a first theoretical value, and calculates, based on the structural information and the position information, a theoretical value of reception strength when indirect waves of radio waves transmitted from the positions of each of the plurality of people are received at the position of the receiving unit, as a second theoretical value; the comparison and determination unit compares a first actual measurement value, which is an actual measurement value of the total reception strength of the direct wave component and the indirect wave component of the radio wave received by the receiving unit, with the first theoretical value to determine the person carrying the transmitting terminal, and if the first actual measurement value and the first theoretical value are similar among the plurality of people, compares a second actual measurement value, which is an actual measurement value of the reception strength of the indirect wave component of the radio wave received by the receiving unit, with the second theoretical value to determine the person carrying the transmitting terminal.

4. The terminal holder detection device according to claim 1, wherein the terminal holder detection device is a terminal holder.

5. the propagation information calculation unit calculates, based on the structural information and the position information, a theoretical value of reception strength when both direct waves and indirect waves of radio waves transmitted from the positions of each of the plurality of people are received at the position of the receiving unit, as a first theoretical value, and calculates, based on the structural information and the position information, a theoretical value of reception strength when indirect waves of radio waves transmitted from the positions of each of the plurality of people are received at the position of the receiving unit, as a second theoretical value; the comparison and determination unit determines whether to determine the person carrying the transmitting terminal by comparing a first actual measurement value, which is an actual measurement value of the total reception strength of the direct wave component and the indirect wave component of the radio wave received by the receiving unit, with the first theoretical value, based on the positional relationship of the plurality of persons, or to determine the person carrying the transmitting terminal by comparing a second actual measurement value, which is an actual measurement value of the reception strength of the indirect wave component of the radio wave received by the receiving unit, with the second theoretical value.

4. The terminal holder detection device according to claim 1, wherein the terminal holder detection device is a terminal holder.

6. the propagation information calculation unit calculates, based on the structural information and the position information, a theoretical value of reception strength when both direct waves and indirect waves of radio waves transmitted from the positions of each of the plurality of people are received at the position of the receiving unit, as a first theoretical value, and calculates, based on the structural information and the position information, a theoretical value of reception strength when indirect waves of radio waves transmitted from the positions of each of the plurality of people are received at the position of the receiving unit, as a second theoretical value; the comparison and determination unit, when an obstacle is present near the line segment connecting any one of the plurality of persons and the receiving unit, compares a second actual measurement value, which is an actual measurement value of the reception strength of the indirect wave component of the radio wave received by the receiving unit, with the second theoretical value to determine the person carrying the transmitting terminal; and, when no obstacle is present near any of the line segments connecting each of the plurality of persons and the receiving unit, compares a first actual measurement value, which is an actual measurement value of the reception strength of the total of the direct wave component and the indirect wave component of the radio wave received by the receiving unit, with the first theoretical value to determine the person carrying the transmitting terminal.

4. The terminal holder detection device according to claim 1, wherein the terminal holder detection device is a terminal holder.

7. the propagation information calculation unit calculates, based on the structural information and the position information, a theoretical value of reception strength when both direct waves and indirect waves of radio waves transmitted from the positions of each of the plurality of people are received at the position of the receiving unit, as a first theoretical value, and calculates, based on the structural information and the position information, a theoretical value of reception strength when indirect waves of radio waves transmitted from the positions of each of the plurality of people are received at the position of the receiving unit, as a second theoretical value; The comparison and determination unit determines whether to determine the person carrying the transmitting terminal by comparing a first actual measurement value, which is the actual measurement value of the reception strength of the total of the direct wave component and the indirect wave component of the radio wave received by the receiving unit, with the first theoretical value, based on the magnitude of the degree of time fluctuation of the actual measurement value of the reception strength of the radio wave received by the receiving unit, or to determine the person carrying the transmitting terminal by comparing a second actual measurement value, which is the actual measurement value of the reception strength of the indirect wave component of the radio wave received by the receiving unit, with the second theoretical value.

4. The terminal holder detection device according to claim 1, wherein the terminal holder detection device is a terminal holder.

8. A receiving device receives radio waves from a transmitting terminal present in the monitored space, Detecting the positions of a plurality of people present within the monitored space; calculating, for each of the plurality of people, a theoretical value of reception strength when an indirect wave of a radio wave transmitted from the position of each of the plurality of people is received at the position of the receiving device, based on structural information stored in advance in a storage device as information on the reflectivity of the radio wave and spatial structure at each location within the monitored space, and position information of the receiving device and the person; Among the plurality of people, an actual measurement value of the reception strength of the indirect wave component of the radio wave transmitted from the transmitting terminal is compared with the theoretical value, and a person who carries the transmitting terminal is identified. A terminal owner detection method characterized by:

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