JP2016114529A - Service area determination device, service area determination method and service area determination program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a service area determination device capable of determining whether or not a receiver is positioned in a predetermined area to which a radio wave is oriented irrespective of existence/absence of obstacle between an antenna emitting a radio wave and a receiver receiving the same.SOLUTION: The service area determination device has a determination section that determines whether the receiver is positioned in the predetermined area based on a difference in strength of reception electric field of two radio waves which are received by the receiver in the plural radio waves oriented to the predetermined area.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an area determination device, an area determination method, and an area determination program.

  As a technique for specifying the position of a person or the like moving in a room, a technique using a wireless communication device that moves with the person or the like is known. For example, the receiving terminal is provided with a directional antenna having a main beam in a direction directly below the receiving terminal as an antenna that receives radio waves from the transmitting terminal. Then, in the arithmetic device, enhancement processing for nonlinearly emphasizing the received electric field strength value obtained at the receiving terminal is performed, and the position of the transmitting terminal is calculated based on the weighted average method from the received electric field strength after enhancement (for example, patent Reference 1).

  A microwave sensor that detects an object using two types of microwaves is also known. A threshold level obtained by changing the value of the signal level of the reflected wave that transmits the object detection signal in accordance with the distance to the object is set in advance for the microwave sensor. Thereby, the phase difference of each reflected wave from the object and the signal level of the reflected wave from the object are recognized. Then, with respect to the distance to the two objects caused by the folding error obtained only by the phase difference, it is determined which distance is the correct distance based on the signal level of the reflected wave (see, for example, Patent Document 2). .

  As another example, the moving direction detection wireless system includes a transmitter and two receivers capable of wireless communication with each other, and the two receivers include an array antenna in which a plurality of antenna elements are arranged. This moving direction detection radio system is further synthesized by a synthesis circuit that synthesizes radio waves received by each antenna element, a phase shift circuit connected between one of the two antenna elements and the synthesis circuit, and a synthesis circuit. It has a receiving circuit for receiving radio waves. At this time, the pair of receivers are arranged with their directivity opposite to each other. Such a moving direction detection wireless system has a simple circuit configuration, high directivity, and reliably detects the moving direction and entry / exit of a person or an object (see, for example, Patent Document 3).

  An estimation device that estimates the position of a mobile station is also known. This estimation apparatus has an antenna capable of receiving both horizontally polarized waves and vertically polarized waves, and is a deviation that is a ratio between the received electric field strength of the horizontally polarized waves and the received electric field strength of the vertically polarized waves received by the antenna. Calculate the wave ratio. Further, the estimation device calculates the amount of time variation of the polarization ratio, and determines that the position estimation accuracy is higher as the polarization ratio is larger and the time variation of the polarization ratio is smaller (for example, Patent Document 4). reference).

JP 2011-163948 A JP 2003-139848 A JP 2008-131196 A JP 2011-257162 A

  However, the technology for detecting the position using the radio wave receiver as described above has the following problems. For example, there is an obstacle between the antenna that emits radio waves and the receiving device that receives the radio waves, the user covers the receiving device with his hand, or the user's body blocks between the antenna and the receiving device. In some cases, the position may not be detected accurately. That is, the received electric field intensity observed at the receiving device is suddenly lowered due to shielding, and as a result, the position of the receiving device cannot be detected normally, and the receiving device is present in a predetermined area where the radio wave is directed. It may be difficult to determine whether or not.

  According to one aspect, the object of the present invention is to determine whether or not the receiving device exists in a predetermined area to which the radio wave is directed, regardless of the presence or absence of a shield between the antenna that emits the radio wave and the receiving device that receives the radio wave. It is possible to judge whether or not.

  A location determination apparatus according to one aspect determines that a receiving apparatus exists in the predetermined area based on a difference in received electric field strength between two radio waves received by the receiving apparatus among a plurality of radio waves directed to the predetermined area. It is characterized by providing the judgment part to perform.

  According to one embodiment, the receiving device determines whether or not the receiving device exists in a predetermined area to which the radio wave is directed, regardless of the presence or absence of an obstacle between the antenna that emits the radio wave and the receiving device that receives the radio wave. Is possible.

It is a figure which shows an example of the radiation pattern of the some electromagnetic wave at the time of performing location determination by 1st Embodiment. It is a figure which shows an example of the hardware constitutions of the located area determination apparatus by 1st Embodiment. It is a figure explaining an example of the in-zone determination method using one electromagnetic wave by a comparative example. It is a figure which shows the example of the radiation pattern of the electromagnetic wave in the in-zone determination method using one electromagnetic wave by a comparative example. It is a figure which shows an example of the located area determination method at the time of using one electromagnetic wave by a comparative example. It is a figure explaining the electromagnetic wave shielding state in the area determination using the electromagnetic wave from one antenna by a comparative example. It is a figure which shows an example of the reception electric field strength RSSI by the located area determination apparatus by 1st Embodiment. It is a figure which shows an example of the reception electric field strength difference (DELTA) RSSI of the electromagnetic wave from two antennas by 1st Embodiment. It is a figure explaining an example of the use condition of the located area determination apparatus by 1st Embodiment. It is a figure which shows an example of the spot information by 1st Embodiment. It is a figure which shows an example of a structure of the antenna used for the area determination by the area determination apparatus by 1st Embodiment. It is a figure which shows another example of the structure of the antenna used for the area determination by the area determination apparatus by 1st Embodiment. It is a figure explaining an example of the feeding method to the antenna by a 1st embodiment. It is a figure which shows an example of the state by which a circularly polarized wave is produced | generated with the patch antenna by 1st Embodiment. It is a flowchart which shows an example of the location determination process by 1st Embodiment. It is a figure explaining an example of the use condition of the located area determination apparatus by 2nd Embodiment. It is a figure which shows an example of the spot information by 2nd Embodiment. It is a flowchart which shows an example of the area determination process by 2nd Embodiment. It is a figure which shows an example of a structure of the located area determination system by 3rd Embodiment. It is a block diagram which shows an example of the hardware constitutions of the computer by 3rd Embodiment. It is a figure which shows an example of the received electric field strength information by 3rd Embodiment. It is a figure which shows an example of the result information by 3rd Embodiment. It is a flowchart which shows an example of the area determination process in the area determination system by 3rd Embodiment. It is a flowchart which shows an example of the reception electric field strength RSSI transmission process of the radio | wireless communication apparatus by 3rd Embodiment. It is a flowchart which shows an example of the area determination process of the computer by 3rd Embodiment. It is a figure which shows an example of the received electric field strength difference information by the modification of 3rd Embodiment.

(First embodiment)
Hereinafter, the location determination apparatus 30 according to the first embodiment will be described with reference to the drawings. FIG. 1 is a diagram illustrating an example of radiation patterns of a plurality of radio waves when performing a location determination according to the first embodiment. FIG. 2 is a diagram illustrating an example of a hardware configuration of the located area determination device 30 according to the first embodiment. In addition, being in the area means that a receiving device that receives radio waves exists in a predetermined area to which the radio waves are directed.

  As shown in FIG. 1, for example, radio waves radiated from the two antennas 11 and 15 are used for the location determination according to the first embodiment. The antenna 11 radiates a radio wave α having, for example, a radiation pattern 13. The antenna 15 radiates a radio wave β having a radiation pattern 17, for example. Here, the radiation pattern 13 and the radiation pattern 17 indicate a range in which a radio wave having a predetermined intensity or more is radiated, for example. Both the radio wave α and the radio wave β are directed to the predetermined area 19. The predetermined area 19 is an example of a predetermined area where radio waves are directed. Predetermined areas such as the predetermined area 19 where radio waves used for in-zone determination are directed may be referred to as spots. In the present embodiment, the presence area means that the area determination device 30 exists in the predetermined area 19. The area determination refers to determining whether or not the area determination device 30 exists in the predetermined area 19. In the present embodiment, the area determination device 30 has the function of a receiving device.

  The antennas 11 and 15 are preferably high gain antennas having sharp directivity in a specific direction. Moreover, it is preferable that the antenna 11 and the antenna 15 radiate radio waves from a position close to each other toward the predetermined region 19. In the example of FIG. 1, the antenna 11 and the antenna 15 radiate radio waves with their radiation surfaces directed downward in the vertical direction, thereby creating a space having a strong reception electric field strength RSSI in a narrow area. That is, the antenna 11 and the antenna 15 create a steep slope of the received electric field strength RSSI at the periphery of the strong received electric field strength Received Signal Strength Indicator (RSSI) space.

  In the example of FIG. 1, the radio wave β has a wider range in which radio waves having a predetermined intensity or higher than the radio wave α are emitted. At this time, the radio waves α and β have different degrees of attenuation as the distance from the predetermined region 19 increases. The predetermined area 19 is an example, and is preferably an area corresponding to the positions of the antenna 11 and the antenna 15. For example, the predetermined area 19 is at least a part of an area where the antenna 11 and the antenna 15 overlap with each other in the vertical direction below the antenna 11 and the antenna 15. For example, the predetermined region 19 may exist in a horizontal plane. Further, when the predetermined area 19 exists in the horizontal plane, the horizontal plane may be an area in the horizontal plane in the vicinity of a height where a person having an average height carries a mobile phone or the like.

  As shown in FIG. 2, the location determination device 30 according to the first embodiment includes a processor 33, a memory 35, a wireless local area network (WLAN: wireless LAN) communication unit 43, an antenna 45, and a display. A portion 47 is provided. The location determination device 30 is, for example, a multi-function mobile phone, a portable information processing device having a radio wave reception function, or the like. The processor 33 is a processing device that performs various processes in the area determination device 30. The memory 35 is a storage device that stores information. The memory 35 stores a location determination program 37, a database 39, and the like. The located area determining program 37 is a program for controlling the operation of the located area determining device 30. The database 39 is a storage area that stores information that is referred to when the location determination program 37 is executed. The memory 35 may include a read only memory (ROM), a random access memory (RAM), and the like.

  The WLAN communication unit 43 is a communication unit that performs wireless data communication with an external device in accordance with a wireless LAN standard, for example, the IEEE 802.11 standard. The WLAN communication unit 43 includes an application program interface (API) 41. The API 41 is an interface for the area determination program 37 to use radio wave information acquired by the WLAN communication unit 43.

  The antenna 45 is a transceiver that transmits and receives radio waves. The display unit 47 is, for example, a liquid crystal display device that displays information. The processor 33 operates the location determination apparatus 30 by reading and executing the location determination program 37. At this time, the processor 33 may realize a function as a determination unit.

  The located area determination device 30 according to the first embodiment, for example, when the difference in received electric field strength received a plurality of radio waves α and β directed to the predetermined area 19 is within a predetermined value, It is determined that it is in the predetermined region 19 related to β.

  Next, a comparative example will be described with reference to FIGS. The comparative example is an example in the case where the area determination is performed using one radio wave directed to a predetermined area. FIG. 3 is a diagram for explaining an example of a location determination method using one radio wave according to a comparative example. FIG. 4 is a diagram illustrating an example of a radio wave radiation pattern in a location determination method using one radio wave according to a comparative example. FIG. 5 is a diagram illustrating an example of a location determination method using one radio wave according to a comparative example.

  As shown in FIG. 3, the antenna 15 radiates a radio wave having a radiation pattern 57 by a transmitter 60. It is assumed that the user 50 has the area determination device 10 that determines the area based on the received electric field intensity obtained by receiving the radio wave from the antenna 15. The located area determining device 10 is basically the same device as the located area determining device 30. However, unlike the location determination device 30, the location determination device 10 is assumed to be a location determination device that determines the location by comparing the intensity of radio waves from only one antenna with a threshold value.

  In the positions represented by the users 50-1, 50-3, and 50-4, whether the radio wave is not detected or the received electric field intensity of the detected radio wave is equal to or less than the threshold value, This is a non-detected state that is determined to be out of the corresponding predetermined area. At the position represented by the user 50-2, the area determination device 10 acquires the received electric field strength of the radio wave received from the antenna 15 and determines that the area is in a predetermined area corresponding to the radiation pattern 57 of the antenna 15. .

  As shown in FIG. 4, the antenna 15 is supplied with power from the transmitter 60 and radiates radio waves. At this time, the antenna 15 has a radiation pattern 72 as indicated by the gain characteristic 70 of the antenna. With such a configuration, it is possible to create a distance-received electric field strength RSSI characteristic in which the received electric field strength RSSI changes sharply according to the position on the horizontal plane as shown in FIG. For example, a range in which a received electric field intensity equal to or higher than a predetermined value is represented by a radiation pattern 57. Therefore, when the user 50 is moving with the area determination device 10 as described above, for example, when the area determination device 10 enters the predetermined area corresponding to the radiation pattern 57 having the diameter 59, the area determination device 10 detects the radio wave of the antenna 15 and acquires the received electric field strength. For example, the diameter 59 may be about 1 meter.

  In FIG. 5, the horizontal axis represents, for example, the distance in the horizontal direction of the area determination device 10 from the center of a predetermined area (predetermined area 19 in FIG. 1) to which radio waves from the antenna 15 are directed. The vertical axis represents the received electric field strength RSSI acquired by the location determination apparatus 10. The received electric field strength 82 is the received electric field strength RSSI received by the in-zone determination device 10. In the area determination device 10, when the threshold value 84 is set and the received electric field strength 82 exceeds the threshold value 84, it is determined that the antenna is located in a predetermined region to which the radio wave of the antenna is directed, and the threshold value 84 or less. In this case, it is determined that the antenna is out of range of the radio wave radiation range.

  For example, when the threshold value 84 is set to -55 dBm, the horizontal distance to the center of the predetermined area 19 is within 0.7 to 0.3 m even if the measured value of the received electric field strength RSSI includes an error of about ± 5 dB. When it becomes, it is detected that the area determination device 10 is in a predetermined area.

  FIG. 6 is a diagram for explaining a radio wave shielding state in a location determination using radio waves from one antenna according to a comparative example. As shown in FIG. 6, in the case where the user 50 exists as a shield, such as when the user 50 is crouching on the area determination device 10 on the radiometer path of the radio wave 87 incident on the area determination device 10 from the antenna 15, There are the following problems. That is, the received electric field strength RSSI in the in-zone determination apparatus 10 is lowered like the shielded received electric field strength 86. In this state, the received electric field strength RSSI decreases even if the user is in the service area, and therefore the service area cannot be accurately determined with the threshold value 84 when there is no shield.

  That is, with the technique of observing the absolute value of the received electric field strength RSSI of one type of radio wave, for example, when the received electric field strength RSSI changes from −50 dBm to −60 dBm, the cause of the change cannot be distinguished. In other words, the located area determining device 10 cannot distinguish whether the cause is a change in the position of the located area determining device 10 or a shielding of a human body or the like. In the example of FIG. 6, for example, when the threshold value for determining the presence / absence of a service area is −55 dBm, erroneous detection occurs as follows. That is, erroneous detection occurs when a received electric field strength RSSI of −65 dBm is observed due to shielding even though the in-zone determination device 10 is actually located inside a predetermined area corresponding to the radiation pattern 57. The in-zone determination device 10 erroneously detects that it has come out of the predetermined area although it actually exists in the predetermined area corresponding to the radiation pattern 57.

  FIG. 7 is a diagram illustrating an example of received electric field strength RSSI by the in-zone determination device 30 according to the first embodiment. In FIG. 7, the horizontal axis is the distance in the horizontal direction of the in-zone determination device 30 from the center of the predetermined area 19 where the radio waves from the antenna 11 and the antenna 15 are irradiated. The vertical axis represents the received electric field strength RSSI acquired by the location determination device 30.

  The received electric field strength 82 and the shielded received electric field strength 84 indicate, for example, the received electric field strength RSSI of the radio wave α from the antenna 11 of FIG. The reception electric field strength 84 at the time of shielding is an example in the case where there is a shielding object that reduces the reception electric field strength between the antenna 11 and the in-zone determination device 30 at about 15 dB. The reception electric field strength 92 and the shielded reception electric field strength 96 indicate, for example, the reception electric field strength RSSI of the radio wave β from the antenna 15 of FIG. The shielded reception field strength 96 is an example in the case where there is a shield between the antenna 15 and the area determination device 30. As shown in FIG. 7, the received electric field strength RSSI tends to attenuate as the distance increases up to a certain distance regardless of the presence or absence of a shield. However, the value of the received electric field strength RSSI is reduced by about 15 dB, for example.

  FIG. 8 is a diagram illustrating an example of a received electric field strength difference ΔRSSI of radio waves from two antennas according to the first embodiment. In FIG. 8, the horizontal axis is the distance in the horizontal direction of the located area determination device 30 from the center of the predetermined area 19 where the radio waves from the antenna 11 and the antenna 15 are irradiated. The vertical axis represents the received electric field strength difference ΔRSSI between the case where there is no shielding object and the case where there is no shielding object calculated by the located area determination device 30. The received electric field strength difference ΔRSSI is an absolute value of the difference between the radio wave from the antenna 11 and the radio wave from the antenna 15. As shown in FIG. 8, the value of the received electric field strength difference ΔRSSI draws a similar curve regardless of the presence or absence of the shield.

  In the example of FIG. 8, the two types of radio waves of the antenna 11 and the antenna 15 are transmitted from approximately the same point so that the received electric field strength RSSI distribution differs depending on the distance from the center of the predetermined region 19. . At this time, as shown in FIG. 8, in the vicinity of the center of the predetermined region 19, the amount of change in the received electric field strength RSSI due to shielding is approximately the same for both of the two types of radio waves. At this time, the difference between the received electric field strengths RSSI of these two types of radio waves is almost zero as shown in FIG. On the other hand, when the received electric field strength RSSI changes differently due to the position of the located area determination device 30 moving away from the center of the predetermined region 19, a difference occurs in the amount of change in the received electric field strength RSSI of the two types of radio waves. Therefore, the received electric field strength difference ΔRSSI of these two types of radio waves varies greatly. With this action, it is possible to detect that the located area determination device 30 has left the predetermined area 19. Therefore, by using this radio wave signal intensity difference ΔRSSI, for example, by comparing the magnitude with a threshold value Th_A or the like, it is possible to appropriately determine the location within the common threshold value regardless of whether there is shielding or not.

  FIG. 9 is a diagram illustrating an example of a usage status of the located area determination device 30 according to the first embodiment. As shown in FIG. 9, it is assumed that the antenna 11 radiates a radio wave α having a radiation pattern 13 under the control of the access point 102 of the wireless LAN. It is assumed that the antenna 15 emits a radio wave β having a radiation pattern 17 under the control of the access point 104 of the wireless LAN. The access point 102 and the access point 104 are wireless LAN access points that are independent of each other. In the present embodiment, the radio wave from antenna 11 is the radio wave of channel ch2. The radio wave from the antenna 15 is the radio wave of the channel ch1.

  The location determination device 30 has a location determination program 37 for the location determination device 30 to make a location determination. The in-zone determination device 30 may realize the function as the determination unit 34 by the processor 33 reading and executing the in-zone determination program 37. Further, a state where the located area determination device 30 exists in a range corresponding to the predetermined area 19 is shown. Location determination device 30 receives broadcast signals output from access point 102 and access point 104, respectively. In other words, the location determination device 30 receives the radio wave of the channel ch1 and the radio wave of the channel ch2, and calculates the radio wave signal intensity difference ΔRSSI with reference to spot information 106 described later. The in-zone determination device 30 performs in-zone determination based on the calculated received electric field strength difference ΔRSSI.

  FIG. 10 is a diagram illustrating an example of the spot information 106 according to the first embodiment. For example, the spot information 106 stores channel information of two radio waves directed to a spot that is a predetermined area capable of receiving two radio waves as shown in FIG. 9 and a threshold value for determining the location. Information. The spot information 106 is preferably stored in advance in, for example, the database 39 of the location determination device 30. The spot information 106 includes two pieces of channel information Ch1 and Ch2 of the spot A and threshold information Th_A. The channel information ch1 and ch2 are preferably information indicating the physical frequency of each radio wave, for example, XX GHz, XX GHz band xx ch, and the like. The threshold information Th_A is a value such as x × dB, for example. The threshold information location determination device 30 calculates the received electric field strength difference ΔRSSI and determines the location by comparing with the threshold if there is a combination of channel radio waves stored in the spot information 106 among the detected radio waves. .

  FIG. 11 and FIG. 12 are diagrams illustrating an example of the configuration of the antenna used for the area determination by the area determination device 30 according to the first embodiment. FIG. 13 is a diagram illustrating an example of a method for feeding power to the antenna according to the first embodiment. FIG. 14 is a diagram illustrating an example of a state where circularly polarized waves are generated by the patch antenna according to the first embodiment.

  FIG. 11 shows an example of the antenna 11. The antenna 11 is a nine-element planar patch antenna, and includes patches 108 in three rows. For example, the used frequency can be 5.18 to 5.7 MHz.

  FIG. 12 shows an example of the antenna 15. The antenna 15 is a four-element planar patch antenna, and includes patches 108 in two rows. For example, the used frequency can be 5.18 to 5.7 MHz. The antenna 15 has a lower gain and a larger half width than the antenna 11. That is, the antenna 11 can have a narrower radiation pattern than the antenna 15.

  FIG. 13 shows a method for supplying power to the patch 108. As shown in FIG. 13, an x-axis and a y-axis perpendicular to the surface of the patch 108 are taken, and a z-axis is defined in the direction of the thickness d. On the x-axis, a feeding point P1 is provided at a position equidistant from the origin O on the y-axis. Voltages having a phase difference of 90 degrees are fed to the two feeding points P1 and P2. For example, a case where a sine wave having an angular velocity of angular velocity ω = 2π / T is input to the feeding point P1, and a sine wave having an angular velocity ω and having a phase difference π / 2 is input to the feeding point P2. Think. In this case, current Im1 = Eodcos (ωt) and Im2 = Eodsin (ωt) are generated in the direction shown in FIG. Note that the period T is the period of the feed wave, and the thickness d is the thickness of the patch 108.

  As shown in FIG. 14, as a result of the power supply as described above, an electric field of, for example, Ex = Acos (ωt−kz) is generated in the x-axis direction, and for example, Ey = Asin (ωt−kz) in the y direction. An electric field is generated. Thus, in front of the patch 108, an electric wave 109 is generated that travels while the electric field vector (Ex, Ey) perpendicular to the z-axis rotates rightward in a direction opposite to the z-axis. Since the electric field vector advances while rotating clockwise with respect to the z axis, the polarization of the patch 108 becomes a right-handed circularly polarized wave. Therefore, the polarization of the antennas such as the antenna 11 and the antenna 15 that combine a plurality of patches 108 is also a right-handed circularly polarized wave, and the gain increases in proportion to the number of combined patches.

  Next, the area determination processing by the area determination device 30 will be described with reference to FIG. FIG. 15 is a flowchart showing the location determination processing according to the first embodiment. The area determination process is performed by the processor 33 reading and executing the area determination program 37 in the area determination device 30.

  As shown in FIG. 15, in the area determination device 30, the WLAN communication unit 43 is activated (S111). The WLAN communication unit 43 receives a radio wave such as a broadcast signal output from a wireless LAN access point, for example. The processor 33 requests the API 41 of the WLAN communication unit 43 to acquire information regarding the radio wave channel acquired by the WLAN communication unit 43 (S112). The processor 33 refers to the radio wave channels ch1 and ch2 used in the area determination in the spot information 106. If there is a channel ch1 in the read radio wave channel information (S113: YES), the processor 33 determines whether there is a channel ch2 (S114). When the channel ch2 is also present (S114: YES), the processor 33 sets the reception field strength RSSI of the channel ch1 as the radio signal strength RSSI1, and sets the reception field strength RSSI of the channel ch2 as the radio signal strength RSSI2 (S115). When there is no channel ch1 or channel ch2 (S113: NO or S114: NO), the processor 33 returns to S112 and repeats the process.

  The processor 33 calculates the received electric field strength difference ΔRSSI = | RSSI1−RSSI2 | from the acquired received electric field strengths RSSI1 and RSSI2 (S116). The processor 33 refers to the spot information 106 and sets a threshold value (S117). For example, in the example of the spot information 106, a threshold value Th_A is set.

  If the received electric field strength difference ΔRSSI is equal to or greater than the threshold (S118: YES), the processor 33 determines that the located area determination device 30 is located. For example, the processor 33 displays “spot detection in progress” or the like on the display unit 47 to indicate that a spot is detected (S119). When the received electric field strength difference ΔRSSI is less than the threshold (S118: NO), the processor 33 determines that the located area determination device 30 is not located. The processor 33 displays “no spot detected” or the like on the display unit 47 to indicate that no spot is detected (S120). The detection of a spot means a state in which it is determined that the located area determination device 30 exists in the predetermined area 19 to which two certain radio waves are directed. The processor 33 returns to S112 and repeats the process.

  As described above, according to the located area judging device 30 according to the first embodiment, for example, the plurality of radio waves α and β directed to the predetermined area 19 are received by the located area judging device 30 having the radio wave receiving device. The received electric field strength difference ΔRSSI which is the difference between the received electric field strengths is calculated. The channel information of the radio waves α and β is preferably stored in advance as spot information 106, for example. That is, the radio wave α and the radio wave β are two predetermined radio waves that are used when determining the presence in the predetermined area 19. The located area determination apparatus 30 determines that the radio wave receiving apparatus, that is, itself is in the predetermined area 19 when the received electric field strength difference ΔRSSI is within a predetermined value. That is, the located area determination device 30 determines its own area based on the received electric field strength difference ΔRSSI. The predetermined area 19 is at least a part of a radio wave detection area such as the access point 102 and the access point 104 that output the radio wave α and the radio wave β.

  As described above, according to the in-zone determination device 30, by using the received electric field strength difference ΔRSSI of a plurality of radio waves, it is possible to accurately determine the location of the receiving device regardless of the presence or absence of the shielding object. For example, when the user covers the area determination device 30 with his / her hand, or when the user's body obstructs between the antennas 11 and 15 and the area determination device 30, observation is performed at the terminal for shielding. The received electric field strength RSSI decreases rapidly. However, since the received electric field strength difference ΔRSSI does not change abruptly, as a result, the in-zone determination device 30 can normally detect the spot, and the in-zone determination can be performed accurately.

  At this time, for example, when two radio waves are set to different frequency radio waves and the frequencies are stored in advance, even when many radio waves are detected, the received electric field strength difference ΔRSSI between the two radio waves stored. Can be calculated. In addition, since the received electric field strength difference ΔRSSI is used, time is not required, for example, measurement is performed in advance to determine a threshold value in accordance with the received electric field strength RSSI. That is, the threshold value does not need to be finely adjusted for each measurement depending on the sensitivity difference due to the model of the location determination device 30 or individual differences, the magnitude of the radio wave transmission output of the antennas 11 and 15 and the access points 102 and 104, and the like. Therefore, it is a location determination apparatus that is highly convenient and reliable and can accurately determine the location. By using circularly polarized waves as radio waves, the radio waves are stably received regardless of the direction of the antenna 45 of the located area determination device 30, and the located area is accurately determined.

  At this time, for example, when it is determined that the area is in the area, the area determination device 30 may output position information indicating the position of the corresponding spot. For example, the output position information may be displayed on a map. The configurations of the antenna 11 and the antenna 15 are not limited to the configurations described above. Further, the polarization state is not limited to circular polarization. The radio wave from the antenna 11 and the radio wave from the antenna 15 are preferably radio waves having different half widths, for example. The frequencies of the radio waves radiated from the antenna 11 and the antenna 15 are preferably different so that, for example, the propagation characteristics in the atmosphere and the degree of attenuation by the shielding are not significantly different from each other.

(Second Embodiment)
Hereinafter, the location determination apparatus 220 according to the second embodiment will be described. In the second embodiment, the same configurations and operations as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 16 is a diagram for explaining an example of a usage situation of the located area determination apparatus according to the second embodiment. As shown in FIG. 16, in the second embodiment, the access point 202 outputs the radio wave represented by the radiation pattern 213 from the antenna 211. Further, the access point 204 outputs a radio wave represented by a radiation pattern 217 from the antenna 215. In the second embodiment, the access point 202 and the access point 204 are independent wireless LAN access points. The radio wave γ from the antenna 211 and the radio wave δ from the antenna 215 preferably have the same frequency, but are modulated with different signals. For example, the radio wave from the antenna 211 is a radio wave modulated according to the identifier Service Set Identifier (SSID) 2 of the access point 202. The radio wave from the antenna 215 is a radio wave modulated according to the identifier SSID 1 of the access point 204. The antenna 211 and the antenna 215 are directional antennas that output radio waves having radiation patterns with different half-widths, for example.

  The hardware configuration of the location determination device 220 may be the same as the hardware configuration of the location determination device 30. The located area determining device 220 includes an existing area determining program 221 that performs different control from the located area determining device 30 and a different data table to be described later. The radiation pattern 213 and the radiation pattern 13 may be substantially the same. The radiation pattern 217 and the radiation pattern 17 may be substantially the same. In the same radiation pattern, the degree of change in the received electric field strength RSSI according to the distance from the center to the in-zone determination device 220 may be the same. Location determination apparatus 220 receives broadcast signals transmitted from access point 202 and access point 204, and acquires the SSID and received field strength RSSI.

  Next, the spot information 225 used when determining the location is described. FIG. 17 is a diagram illustrating an example of spot information according to the second embodiment. As shown in FIG. 17, the spot information 225 is information for determining presence in a plurality of predetermined areas such as a spot C and a spot D, for example. For example, if a predetermined area to which radio waves from the access point 202 and the access point 204 shown in FIG. 16 are directed is a spot C, the spot information 225 includes a spot corresponding to a predetermined area different from the predetermined area of the spot C. Information on D and the like is also stored.

  For one spot, the identifiers SSID1 and SSID2 of the access points that output each of the two radio waves, and a threshold value used for determining the location are stored. For the spot C, for example, the identifier SSID1 is stored as “AA”, the identifier SSID2 is stored as “AB”, and the threshold is stored as a threshold Th_C. The threshold value information Th_C of the spot C and the threshold value information Th_D of the spot D may be the same value. In this case, the threshold information may not be included in the spot information 225.

  Hereinafter, the location determination processing according to the second embodiment will be described with reference to a flowchart. FIG. 18 is a flowchart showing a location determination process according to the second embodiment. The area determination process is performed by the processor 33 reading and executing the area determination program 221 in the area determination device 220. Here, for example, a location determination process regarding the spot C will be described.

  As shown in FIG. 18, in the located area determination apparatus 220, the WLAN communication unit 43 is activated (S231). The WLAN communication unit 43 receives a radio wave such as a broadcast signal output from a wireless LAN access point, for example. The processor 33 requests the API 41 of the WLAN communication unit 43 to acquire information related to the radio wave acquired by the WLAN communication unit 43 (S232). The processor 33 refers to the identifiers SSID1 and SSID2 of the radio waves used for determining the location of the spot C in the spot information 205. In the spot C, according to the spot information 205, SSID1 = AA and SSID2 = AB.

  The processor 33 analyzes the read radio wave and, for example, if there is SSID1 = AA (S233: YES), it determines whether there is SSID2 = AB (S234). If there is also the identifier SSID2 = AB (S234: YES), the processor 33 sets the reception field strength RSSI of the identifier SSID1 as the radio signal strength RSSI1, and sets the reception field strength RSSI of the identifier SSID2 as the radio signal strength RSSI2 (S235). ). When there is no identifier SSID1 or identifier SSID2 (S233: NO or S234: NO), the processor 33 returns to S232 and repeats the process. At this time, for example, the processor 33 may proceed to S204 to be described later, and display “Spot not detected” on the display unit 47.

  The processor 33 calculates the received electric field strength difference ΔRSSI = | RSSI1−RSSI2 | from the acquired received electric field strengths RSSI1 and RSSI2 (S236). The processor 33 refers to the spot information 106 and sets the threshold value to, for example, the threshold value Th_C (S237). When the received electric field strength difference ΔRSSI is equal to or larger than the threshold (S238: YES), the processor 33 displays, for example, “spot is being detected” on the display unit 47 to indicate that a spot is detected (S239). . When the received electric field strength difference ΔRSSI is less than the threshold (S238: NO), the processor 33 displays “Spot not detected” or the like on the display unit 47 to indicate that no spot is detected (S240). Returning to S232, the process is repeated.

  As described above, according to the location determination apparatus 220 according to the second embodiment, for example, a plurality of radio waves γ and δ directed to the predetermined area 19 are received by the location determination apparatus 220 having a reception device. A received electric field strength difference ΔRSSI that is a difference in received electric field strength is calculated. Information relating to the radio waves γ and δ, here, the identifier SSID, is preferably held in advance as, for example, spot information 205. The located area determination apparatus 220 determines that the radio wave receiving apparatus, that is, itself is in the predetermined area 19 when the received electric field strength difference ΔRSSI is within a predetermined value. The predetermined region 19 is, for example, a region to which the radio wave α and the radio wave β are directed, and may be at least a part of a region where the radio signal intensity RSSI of a predetermined level or higher is observed.

  As described above, according to the in-zone determination device 220, by using the received electric field strength difference ΔRSSI of a plurality of radio waves, it is possible to accurately determine the location of the receiving device regardless of the presence or absence of a shield. For example, when the user covers the area determination device 220 with his / her hand or the user's body obstructs the area between the antennas 11 and 15 and the area determination device 220, the terminal is observed for shielding. The received electric field strength RSSI decreases rapidly. However, since the received electric field strength difference ΔRSSI does not change abruptly, as a result, the in-zone determination device 220 can normally detect the spot and perform the in-zone determination.

  In the area determination device 220 according to the second embodiment, in addition to the effects of the area determination device 30 according to the first embodiment, there are the following effects. That is, since there are more types of identifiers SSID than types of radio wave frequencies that can be used, it is possible to create a larger number of two types of radio waves. Therefore, it is possible to determine the presence of many areas.

(Third embodiment)
Hereinafter, the location determination system 320 according to the third embodiment will be described. The third embodiment is an example in which a device that receives radio waves and a device that determines a location are different devices. In the third embodiment, configurations and operations similar to those in the first embodiment or the second embodiment are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 19 is a diagram illustrating an example of a configuration of a location determination system 320 according to the third embodiment. The located area determination system 320 is a system in which a computer 300 and a wireless communication device 330 are connected via a communication network 350. The wireless communication device 330 is an example of a receiving device.

  As shown in FIG. 19, whether or not the wireless communication device 330 is in a predetermined area to which the radio wave α from the antenna 11 and the radio wave β from the antenna 15 are directed is the same as that in the first embodiment. An explanation will be given using a case where the area is determined as an example. That is, the radio wave α, the radio wave, and β are radio waves having different frequencies. The wireless communication device 330 is, for example, a mobile phone or a portable information processing device having a radio wave reception function.

  As an example of the hardware configuration of the wireless communication device 330, the same configuration as that of the location determination device 30 according to the first embodiment can be considered. However, as a program, it is preferable to have, for example, a radio wave signal strength transmission program 332 instead of the in-zone determination program 37. The radio signal strength transmission program 332 is a program for transmitting the acquired radio wave channel information, the received electric field strength RSSI, and the like to the computer 300 via the communication network 350, receiving the location determination result, and displaying the result. is there.

  In the third embodiment, the wireless communication device 330 uses the received radio wave channel information and the received electric field strength RSSI of each radio wave as the received electric field strength information 360, which will be described later, via the communication network 350. To the computer 300. The communication network 350 may be any one of the Internet, a mobile phone communication network, an intranet, and the like, for example. The communication network 350 may be a wireless communication network, a wired communication network, or the like. As a method of performing communication via the communication network 350, the wireless communication device 330 may perform communication via the access point 102 or the access point 104 by wireless communication 334. In the wireless communication device 330, the processor may perform the above process by reading and executing the radio signal strength transmission program 332.

  When the computer 300 receives the received electric field strength information 360 from, for example, the wireless communication device 330, the computer 300 performs a process of determining the location as in the location determination device 30. As a result of the processing, it is preferable to transmit information indicating presence / absence of the service area and information indicating the position of the service area to the wireless communication device 330 when the service area is present. For example, the computer 300 preferably transmits result information 362 to be described later to the wireless communication device 330. As a program for performing such processing, the computer 300 preferably has a location determination program 321. The computer 300 may be a standard computer.

  FIG. 20 is a block diagram illustrating an example of a hardware configuration of the computer 300. As shown in FIG. 20, a computer 300 includes a central processing unit (CPU) 302, a memory 304, an input device 306, an output device 308, an external storage device 312, a medium drive device 314, a network connection device 318, and the like via a bus 310. Connected.

  The CPU 302 is an arithmetic processing unit that controls the operation of the entire computer 300. The memory 304 is a storage unit for storing in advance a program for controlling the operation of the computer 300 or using it as a work area when necessary when executing the program. The memory 304 is, for example, a random access memory (RAM), a read only memory (ROM), or the like. The input device 306 is a device that, when operated by a computer user, acquires various information input from the user associated with the operation content and sends the acquired input information to the CPU 302. Keyboard device, mouse device, etc. The output device 308 is a device that outputs a processing result by the computer 300, and includes a display device and the like. For example, the display device displays text and images according to display data sent by the CPU 302.

  The external storage device 312 is a storage device such as a hard disk, and stores various control programs executed by the CPU 302, acquired data, and the like. In the present embodiment, the location determination program 321 may be stored in the external storage device 312. Further, the received electric field strength information 360 received from the wireless communication device 330 may be stored in the external storage device 312, for example. Further, the spot information 106 described in the first embodiment may be stored as the database 323 of the external storage device 312.

  The medium driving device 314 is a device for writing to and reading from the portable recording medium 316. The CPU 302 can read out and execute a predetermined control program recorded on the portable recording medium 316 via the medium driving device 314 to perform various control processes. The portable recording medium 316 is, for example, a Compact Disc (CD) -ROM, a Digital Versatile Disc (DVD), a Universal Serial Bus (USB) memory, or the like. The network connection device 318 is an interface device that manages transmission / reception of various data performed with the outside, such as the wireless communication device 330 via the communication network 350, by wire or wireless. A bus 310 is a communication path for connecting the above devices and the like to exchange data.

  The location determination program 321 that causes the computer to execute the location determination method according to the third embodiment is stored in the external storage device 312 as described above, for example. The CPU 302 reads an area determination program 321 from the external storage device 312 and executes the program using the memory 304 to perform an area determination operation. At this time, first, a location determination program 321 for causing the CPU 302 to perform a location determination process is created and stored in the external storage device 312. Then, a predetermined instruction is given to the CPU 302 from the input device 306 so that the location determination program 321 is read from the external storage device 312 and executed. Further, the location determination program 321 may be stored in the portable recording medium 316.

  As described above, the computer 300 receives the received electric field strength RSSI from the wireless communication device 330, refers to the spot information 106, and calculates the received electric field strength difference ΔRSSI when the corresponding received electric field strength RSSI. , Make a location determination.

  21 and 22 show an example of information exchanged in the third embodiment. FIG. 21 is a diagram illustrating an example of the received electric field strength information 360 according to the third embodiment. FIG. 22 is a diagram illustrating an example of the result information 362 according to the third embodiment.

  As shown in FIG. 21, the received electric field strength information 360 is information for notifying the reception status of radio waves from the wireless communication device 330 to the computer 300. The received electric field strength information 360 may include channel information of all detected radio waves and the received electric field strength RSSI. The received electric field strength information 360 can be modified, for example, to include information on a predetermined number of radio waves having a large received electric field strength RSSI among the detected radio waves.

  As shown in FIG. 22, the result information 362 is information for notifying the wireless communication device 330 of the result of the area determination in the computer 300. The result information 362 includes, for example, information indicating whether a spot is detected and information indicating a spot name. For example, when the computer 300 has only the spot information 106, the spot name may be omitted.

  Hereinafter, the area determination processing by the area determination system 320 according to the third embodiment will be described with reference to a flowchart. FIG. 23 is a flowchart showing the area determination processing in the area determination system 320 according to the third embodiment. FIG. 24 is a flowchart illustrating received field strength RSSI transmission processing of the wireless communication device 330 according to the third embodiment. FIG. 25 is a flowchart showing the location determination process of the computer 300 according to the third embodiment.

  As shown in FIG. 23, first, the wireless communication device 330 transmits a radio wave reception result to the computer 300 (S371). For example, the transmitted information is received field strength information 360. Details of the processing of S371 will be described later. The transmission method is performed via the communication network 350 as described above.

  When the computer 300 receives, for example, the received electric field strength information 360 from the wireless communication device 330, the computer 300 determines the location (S372). For the location determination, for example, the method described in the first embodiment or the second embodiment is employed. Here, the case where two radio waves described in the first embodiment are modulated at different frequencies will be described.

  The computer 300 transmits, for example, result information 362 to the wireless communication device 330 as the determination result in S372 (S373). The wireless communication device 330 receives the result (S374), and outputs the result based on the received result information 362 (S375).

  As shown in FIG. 24, in S371, the wireless communication device 330 activates the WLAN communication unit 43 (S381). The WLAN communication unit 43 receives a radio wave such as a broadcast signal output from a wireless LAN access point, for example. The processor 33 requests the API 41 of the WLAN communication unit 43 for information on the acquired radio wave channel (S382). The processor 33 acquires a set of channel information (for example, channel ch1) of each of the detected plurality of radio waves and a reception field intensity RSSI (for example, reception field intensity RSSI1) of each radio wave (S383). The wireless communication device 330 transmits, for example, the received electric field strength information 360 including the set of the acquired radio wave channel information and the received electric field strength RSSI to the computer 300 (S384). The wireless communication device 330 returns the process to the process of FIG.

  As shown in FIG. 25, the computer 300 receives a set of channel information and received field strength RSSI based on information from the wireless communication device 330 such as received field strength information 360 (S391). The computer 300 determines whether there is a combination of channels in the spot information 106 in the received channel information, and if not, repeats the processing from S391 (S392: NO).

  When the combination of channels in the spot information 106 is included in the received channel information (S392: YES), the computer 300 calculates the received electric field strength difference ΔRSSI (S393). The computer 300 reads and sets the threshold value from the spot information 106 (S394). When the calculated received electric field strength difference ΔRSSI is equal to or less than the set threshold value (S395: YES), the computer 300 determines that the wireless communication device 330 is located in the spot A (S396). If the calculated received electric field strength difference ΔRSSI is larger than the set threshold (S395: NO), the computer 300 determines that the wireless communication device 330 is not located in the spot A (S396). The computer 300 transmits a determination result such as the result information 362 to the wireless communication device 330 (S398).

  As described above, in the located area determination system 320 according to the third embodiment, the computer 300 determines whether or not the wireless communication device 330 is located in a predetermined area. The determination method is the same as in the first embodiment, but as described in the second embodiment, radio waves modulated by different signals may be used.

  According to the location determination system 320 according to the third embodiment, in addition to the effects of the location determination method according to the first embodiment and the second embodiment, there are the following effects. That is, it is not necessary to have the in-zone determination program and spot information for the wireless communication device 330 to determine. Therefore, the wireless communication device 330 can reduce the load on the memory and the processor. In addition, it is generally possible to make the area determination more quickly by performing the area determination process using the computer 300 having a higher processing capability than the wireless communication device 330.

(Modification of the third embodiment)
Hereinafter, a modification of the third embodiment will be described. The same configurations and operations as those in the first to third embodiments are denoted by the same reference numerals, and redundant description is omitted. This modification is an example in which in-zone determination system 320 according to the third embodiment transmits reception field strength difference information 364 from wireless communication device 330 to computer 300 instead of reception field strength information 360.

  FIG. 26 is a diagram illustrating an example of the received electric field strength difference information 364 according to the modification of the third embodiment. As shown in FIG. 26, in the present modification, the wireless communication device 330 calculates the received electric field strength difference ΔRSSI instead of the received electric field strength RSSI and transmits it to the computer 300. In the computer 300, the channel information included in the received electric field strength difference information 364 is referred to by the spot information 106, and the in-service area determination is performed by setting a corresponding threshold value.

  When three or more radio waves are acquired, the wireless communication device 330 may calculate the difference between two radio waves of all combinations selected from the acquired received electric field strength RSSI as the received electric field strength difference ΔRSSI. . At this time, the wireless communication device 330 may have the spot information 106 and calculate the difference in the received electric field strength RSSI corresponding to the spot in advance.

  As described above, according to the modification according to the third embodiment, in addition to the effect of the location determination method according to the first embodiment and the second embodiment, as in the third embodiment. It has the following effects. That is, it is not necessary to have the in-zone determination program and spot information for the wireless communication device 330 to determine. Therefore, the wireless communication device 330 can reduce the load on the memory and the processor. In addition, it is generally possible to make the area determination more quickly by performing the area determination process using the computer 300 having a higher processing capability than the wireless communication device 330.

  As described above, according to the first to third embodiments and the modification of the third embodiment, the difference in the received electric field intensity received by the receiving device among the plurality of radio waves directed to the predetermined area. Thus, the presence / absence of the receiving device is determined. That is, the presence / absence of a receiving device is determined in a predetermined area where radio waves from a plurality of antennas are radiated. At this time, the antenna preferably has high directivity. According to the location determination method, the position of the wireless communication device or the like can be detected with high accuracy, for example, from several tens of centimeters to several meters. Moreover, it is possible to detect a region where the received electric field strength RSSI changes with a steep slope of a certain level or more using two radio waves. Therefore, the position is accurately detected regardless of the presence or absence of the shielding object and the performance of the apparatus.

  The present invention is not limited to the embodiments described above, and various configurations or embodiments can be adopted without departing from the gist of the present invention. For example, the radio wave radiation pattern is not limited to the illustrated example. Further, the predetermined area 19 can be modified, for example, when a person moves with the area determination device 30 or the like at a position where there is a high probability that the area determination device 30 exists. The processing order of the flowchart described above is an example, and is not limited to the example described.

The following additional notes are disclosed with respect to the first to third embodiments and the modified examples of the third embodiment.
(Appendix 1)
A judging unit for judging that the receiving device exists in the predetermined region based on a difference in received electric field strength between two radio waves received by the receiving device among a plurality of radio waves directed to the predetermined region. Location determination device.
(Appendix 2)
The area determination device according to appendix 1, wherein the plurality of radio waves have different degrees of attenuation as the distance from the predetermined area increases.
(Appendix 3)
The in-zone determination device according to appendix 1 or appendix 2, wherein the plurality of radio waves are two types of radio waves having different frequencies such that differences in properties such as attenuation and propagation characteristics can be ignored.
(Appendix 4)
The in-zone determination device according to any one of appendix 1 to appendix 3, wherein the plurality of radio waves are two types of radio waves modulated by different signals.
(Appendix 5)
The in-zone determination device according to any one of appendix 1 to appendix 4, wherein each of the plurality of radio waves is a circularly polarized radio wave.
(Appendix 6)
The computer that makes the location determination
Determining that the receiving apparatus is present in the predetermined area when a difference in received electric field strength between two radio waves received by the receiving apparatus is within a predetermined value among a plurality of radio waves directed to the predetermined area; How to determine where you are.
(Appendix 7)
The location determination method according to appendix 6, wherein the plurality of radio waves have different degrees of attenuation as the distance from the predetermined area increases.
(Appendix 8)
The location determination method according to appendix 6 or appendix 7, wherein the plurality of radio waves are two types of radio waves having different frequencies such that differences in properties such as attenuation and propagation characteristics can be ignored.
(Appendix 9)
The location determination method according to any one of appendix 6 to appendix 8, wherein the plurality of radio waves are two types of radio waves modulated by different signals.
(Appendix 10)
The location determination method according to any one of appendix 6 to appendix 9, wherein each of the plurality of radio waves is a circularly polarized radio wave.
(Appendix 11)
Processing for determining that the receiving device is present in the predetermined region when a difference in received electric field strength between two radio waves received by the receiving device is within a predetermined value among a plurality of radio waves directed to the predetermined region A location determination program to be executed.
(Appendix 12)
The presence determination program according to appendix 11, wherein the plurality of radio waves have different degrees of attenuation as the distance from the predetermined area increases.
(Appendix 13)
The presence determination program according to appendix 11 or appendix 12, wherein the plurality of radio waves are two types of radio waves having different frequencies such that differences in properties such as attenuation and propagation characteristics can be ignored.
(Appendix 14)
14. The location determination program according to any one of appendix 11 to appendix 13, wherein the plurality of radio waves are two types of radio waves modulated by different signals.
(Appendix 15)
The location determination program according to any one of Supplementary Note 11 to Supplementary Note 14, wherein the plurality of radio waves are radio waves that are circularly polarized.

DESCRIPTION OF SYMBOLS 11 Antenna 13 Radiation pattern 10 Area determination apparatus 15 Antenna 17 Radiation pattern 19 Predetermined area 30 Area determination apparatus 33 Processor 34 Determination part 35 Memory 37 Area determination program 39 Database 41 API
43 WLAN communication unit 45 Antenna 47 Display unit 50 User 52 Movement direction 55 Transmitter 57 Radiation pattern 52 Processor 60 Transmitter 70 Antenna gain characteristic 72 Radiation pattern 80 Received electric field strength change example 82 Received electric field strength 84 Threshold 86 Received electric field when shielded Strength 92 Received electric field strength 94 Shielded received field strength 96 Received field strength difference 98 Shielded received field strength difference 102 Access point 104 Access point 106 Spot information 108 Patch 109 Radio wave

Claims (7)

A determination unit that determines that the receiving device is present in the predetermined region based on a difference in received electric field strength between two radio waves received by the receiving device among a plurality of radio waves directed to the predetermined region;
A location determination apparatus comprising: The in-zone determination apparatus according to claim 1, wherein the plurality of radio waves have different degrees of attenuation as the distance from the predetermined area increases. The in-zone determination device according to claim 1 or 2, wherein the plurality of radio waves are two types of radio waves having different frequencies such that differences in properties such as attenuation and propagation characteristics can be ignored. The in-zone determination device according to any one of claims 1 to 3, wherein the plurality of radio waves are two types of radio waves modulated by different signals. The in-zone determination apparatus according to any one of claims 1 to 4, wherein each of the plurality of radio waves is a circularly polarized radio wave. The computer that makes the location determination
Determining that the receiving apparatus is present in the predetermined area when a difference in received electric field strength between two radio waves received by the receiving apparatus is within a predetermined value among a plurality of radio waves directed to the predetermined area; How to determine where you are. Processing for determining that the receiving device is present in the predetermined region when a difference in received electric field strength between two radio waves received by the receiving device is within a predetermined value among a plurality of radio waves directed to the predetermined region A location determination program to be executed.