Measurement device, measurement method, and measurement program

Abstract

To measure the communication performance of a communication system with high accuracy.SOLUTION: A measuring device 10 includes a detection unit 12C and a derivation unit 12D. The detection unit 12C detects vibration width of an antenna 21 that receives a measurement target radio wave 52A from a vehicle T equipped with a communication system 30 that transmits the measurement target radio wave 52A based on a first transmission radio wave 50A received by the antenna 21. When the vibration width becomes larger than 0 and equal to or less than set width that is larger than 0, the derivation unit 12D derives the communication performance of the communication system 30 based on a second received radio wave 52B, which is the measurement target radio wave 52A received by the antenna 21.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a measurement device, a measurement method, and a measurement program. [Background technology]

[0002] Conventionally, there is known a system that receives radio waves emitted from a communication system mounted on an object such as a mobile phone or a vehicle with an antenna and derives the communication performance of the communication system based on the received radio waves (see, for example, Patent Document 1). In addition, in the case of a large object, a large mechanism is prepared and radio waves are received while moving the mechanism with a movable part. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2019-505768 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the antenna may vibrate due to the movement of the moving part. In the conventional technology, in order to prevent the measurement accuracy from decreasing, the measurement is performed after waiting until the antenna stops vibrating by visual inspection. In other words, in the conventional technology, it is difficult to measure the communication performance of the communication system with high accuracy while the antenna is vibrating.

[0005] An object of the present disclosure is to provide a measurement device, a measurement method, and a measurement program that are capable of measuring the communication performance of a communication system with high accuracy. [Means for solving the problem]

[0006] The measuring device according to the present disclosure comprises: A call control unit; The detector includes a detection unit and a derivation unit. The transmission control unit causes the antenna to transmit radio waves for vibration detection.The detection unit receives the measurement target radio wave from an object equipped with a communication system that transmits the measurement target radio wave. The above The amplitude of the antenna is measured by the The vibration detection radio wave is a reflected wave from the object. First received signal and the vibration detection radio wave Based on At least one of the swing angle and the swing amount of the antenna corresponding to the difference between the derived distance between the antenna and the target and the set distance between the antenna and the target is set as the vibration width of the antenna. The derivation unit derives communication performance of the communication system based on a second received radio wave, which is the measurement target radio wave received by the antenna, when the oscillation width is greater than 0 and is equal to or smaller than a set width greater than 0. Effect of the Invention

[0007] According to the measurement device, the measurement method, and the measurement program of the present disclosure, it is possible to measure the communication performance of a communication system with high accuracy. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing an example of a measurement system according to an embodiment. [Diagram 2] FIG. 2 is a functional block diagram of an example of the measurement device. [Diagram 3] FIG. 3 is a schematic diagram of an example of the first received radio wave. [Figure 4] FIG. 4 is a flowchart showing an example of the flow of information processing executed by the measurement device. [Diagram 5] FIG. 5 is a schematic diagram showing an example of a measurement system according to an embodiment. [Figure 6] FIG. 6 is a functional block diagram of an example of a measurement device. [Figure 7] FIG. 7 is an explanatory diagram of an example of detection of the vibration amplitude of the antenna by the detection unit. [Figure 8] FIG. 8 is a flowchart showing an example of the flow of information processing executed by the measurement device. [Figure 9] FIG. 9 is a diagram illustrating a hardware configuration of an example of a measurement device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of a measurement device, a measurement method, and a measurement program according to the present disclosure will be described with reference to the accompanying drawings.

[0010] (First embodiment) 1 is a schematic diagram showing an example of a measurement system 1 according to the present embodiment. The measurement system 1 includes a measurement device 10, a measurement mechanism 20, and a fixed wave source 40.

[0011] The measurement system 1 is a system for measuring the communication performance of a communication system 30 mounted on a target.

[0012] The target is an object equipped with the communication system 30. The target may be any object capable of being equipped with the communication system 30. The target may be, for example, a vehicle T, a flying object such as an airplane, a ship, a structure such as a building, a mobile terminal, an electronic device such as a personal computer, etc. In this embodiment, a form in which the target is a vehicle T will be described as an example.

[0013] The communication system 30 is a radio wave transmitter that wirelessly transmits the measurement target radio wave 52A. In other words, the communication system 30 is a radio wave transmitter that transmits the measurement target radio wave 52A into the air. The communication system 30 is, for example, a cordless telephone device, a wireless communication device such as a Wi-Fi (Wireless Fidelity) router, a radar transmitter, etc. Also, the communication system 30 is, for example, various transmitters used for tracking, detection, communication, etc.

[0014] The measurement target radio wave 52A is a radio wave wirelessly transmitted from the communication system 30. The measurement target radio wave 52A is a radio wave to be measured in the measurement system 1 of this embodiment. The measurement target radio wave 52A may be any of millimeter waves, microwaves, ultra-high frequency radio waves, ultra-high frequency radio waves, short waves, medium waves, and long waves. The millimeter waves are radio waves in the millimeter wave frequency band of 26 GHz or higher. The millimeter waves are used in mobile communication systems such as 5G (fifth generation mobile communication system), autonomous driving technology for vehicle T, ADAS (Advanced Driver Assistance System) technology, and the like. The radio waves used in ADAS technology include, for example, radar waves.

[0015] In this embodiment, the communication system 30 is mounted on a vehicle T, which is an example of a target. In this embodiment, a form in which the communication system 30 is mounted inside the vehicle T will be described as an example.

[0016] The measurement mechanism 20 is a mechanism for receiving the measurement target radio waves 52A transmitted from the communication system 30 mounted on the vehicle T. The measurement mechanism 20 is configured to be at least partially movable so that the measurement target radio waves 52A can be received at each of the positions in all directions of the vehicle T.

[0017] In detail, the measurement mechanism 20 includes an antenna 21, a support portion 22, a support portion 23, and a support portion 24.

[0018] The antenna 21 is a device for receiving and transmitting radio waves. In other words, the antenna 21 emits radio waves into the air and receives radio waves that have propagated through the air.

[0019] The antenna 21 is supported by a support portion 24. The support portion 24 is a rod-shaped member. The support portion 24 supports the antenna 21 at one end in the longitudinal direction, and the other end is supported by the support portion 23. In this embodiment, a form in which the support portion 24 is arranged so that the longitudinal direction of the support portion 24 and a direction intersecting the vertical direction approximately coincide with each other will be described as an example.

[0020] The support portion 23 is a rod-shaped member. In this embodiment, a form in which the support portion 23 is arranged so that the longitudinal direction of the support portion 23 and the vertical direction are approximately aligned will be described as an example. One end of the support portion 23 in the longitudinal direction is supported by the support portion 22. The support portion 22 is a rod-shaped member that is arranged on the ground or the like. In this embodiment, a form in which the longitudinal direction of the support portion 22 is approximately aligned with the horizontal direction will be described as an example.

[0021] The support part 25 is a member that supports the vehicle T. In this embodiment, the support part 25 is a disk-shaped member. In this embodiment, the disk-shaped surface of the support part 25 is arranged so as to be oriented along the horizontal direction. A drive part 25A is provided at the center of the circle of the support part 25. The drive part 25A is driven under the control of the measuring device 10, which will be described later. Drive of the drive part 25A causes the support part 25 to rotate at predetermined angles around the center of the circle as the center of rotation (in the direction of arrow Q). As the support part 25 rotates, the vehicle T placed on the support part 25 rotates (in the direction of arrow Q).

[0022] Support section 23 is provided with drive section 23A. Support section 24 is provided with drive section 24A. Drive sections 23A and 24A are driven under the control of measuring device 10, which will be described later. Drive section 23A moves support section 23 along the longitudinal direction of support section 22 (arrow X direction). Drive section 24A moves support section 24 along the longitudinal direction of support section 23 (arrow Z direction).

[0023] Antenna 21 supported by support unit 24 is supported so as to be movable in a direction approaching or moving away from vehicle T in the vertical direction and in a direction intersecting the vertical direction, by the drive of drive unit 23A and drive unit 24A. In other words, antenna 21 is supported so as to be movable between the apex of hemisphere C, whose center is vehicle T, and the periphery of hemisphere C, by the drive of drive unit 23A and drive unit 24A.

[0024] The fixed wave source 40 is a stationary radio wave transmission source. In this embodiment, the radio wave transmission source is a radio wave transmission device that wirelessly transmits the first transmission radio wave 50A. That is, the fixed wave source 40 is a radio wave transmission device that transmits the first transmission radio wave 50A into the air.

[0025] The first transmission radio wave 50A transmitted from the fixed wave source 40 is a constant radio wave whose wavelength, period, amplitude, and speed do not change over time. The period means the number of vibrations or frequency. The speed is expressed by the absolute value of the speed. In this embodiment, the first transmission radio wave 50A is described as a sine wave as an example.

[0026] The stationary state means that a state in which the fixed wave source 40 does not vibrate is maintained even if at least one of the measurement device 10, the measurement mechanism 20, and the vehicle T vibrates. In other words, the fixed wave source 40 is a radio wave emitting source that maintains a stationary state in which the fixed wave source 40 does not vibrate even if at least one of the measurement device 10, the measurement mechanism 20, and the vehicle T vibrates.

[0027] For example, the fixed wave source 40 is installed in a location that is not affected by vibrations of the measurement device 10, the measurement mechanism 20, and the vehicle T. Also, for example, the fixed wave source 40 may be configured to be placed on a vibration absorbing member that absorbs vibrations.

[0028] The fixed wave source 40 may be any radio wave transmitting source that transmits the first transmitted radio wave 50A in a stationary state. For example, the same radio wave transmitting device as that of the communication system 30 may be used as the fixed wave source 40, or a radio wave transmitting device different from that of the communication system 30 may be used. When the same radio wave transmitting device as that of the communication system 30 is used as the fixed wave source 40, the radio wave transmitting device can be used as the fixed wave source 40 by installing the radio wave transmitting device in a place where the stationary state is maintained.

[0029] It is preferable that the fixed wave source 40 maintains a stationary state and is placed in an environment where no other members are present between the fixed wave source 40 and the antenna 21. Alternatively, it is preferable that the fixed wave source 40 maintains a stationary state and is placed in an environment where the conditions of the other members present between the fixed wave source 40 and the antenna 21 do not change over time. The conditions of the other members refer to elements of the other members that affect the radio waves received by the antenna 21. The conditions of the other members include, for example, the type, position, and shape of the other members.

[0030] Next, a description will be given of the measurement device 10. The measurement device 10 is a device for measuring the communication performance of the communication system 30 based on a measurement target radio wave 52A of the communication system 30 received by an antenna 21.

[0031] Fig. 2 is a functional block diagram of an example of the measurement device 10. Fig. 2 also shows electrical components other than the measurement device 10 included in the measurement system 1.

[0032] The measurement device 10 includes a processing unit 12, a communication unit 14, a storage unit 16, and an output unit 18. The processing unit 12, the communication unit 14, the storage unit 16, and the output unit 18 are connected to each other so as to be able to communicate with each other via a bus 19, for example.

[0033] The communication unit 14 is communicatively connected to the drive units 23A, 24A, 25A, and the antenna 21. In this embodiment, a form in which the communication unit 14 is communicatively connected to each of the drive units 23A, 24A, 25A, and the antenna 21 via wires will be described as an example. Also, in this embodiment, a form in which the communication unit 14 is communicatively connected to each of the fixed wave source 40 and the communication system 30 via wires will be described as an example.

[0034] The storage unit 16 stores various types of information. The output unit 18 outputs various types of information. The output unit 18 is, for example, a display that displays images, a speaker that outputs sound, etc. The output unit 18 may have a communication function for communicating with an external information processing device via a network or the like. By having the communication function, the output unit 18 can transmit various types of information to the external information processing device.

[0035] The processing unit 12 executes various information processing. In this embodiment, the processing unit 12 includes a drive control unit 12A, a transmission control unit 12B, a detection unit 12C, and a derivation unit 12D. Some or all of the drive control unit 12A, the transmission control unit 12B, the detection unit 12C, and the derivation unit 12D may be realized by, for example, having a processing device such as a CPU (Central Processing Unit) execute a program, that is, by software, or by hardware such as an IC (Integrated Circuit), or by using both software and hardware. In addition, at least one of the drive control unit 12A, the transmission control unit 12B, the detection unit 12C, and the derivation unit 12D may be mounted on an external information processing device communicably connected to the measurement device 10 via a network or the like.

[0036] The drive control unit 12A controls the drive units 23A, 24A, and 25A. For example, the drive control unit 12A drives the drive units 23A, 24A, and 25A so that the antenna 21 is sequentially arranged in each region obtained by dividing the outer periphery of a hemisphere C (see FIG. 1) centered on the vehicle T into a plurality of regions. In detail, the drive control unit 12A controls the drive unit 25A every time the position of the antenna 21 is moved and controlled to the next measurement position between the apex of the hemisphere C and the periphery of the hemisphere C by driving the drive units 23A and 24A. By controlling the drive unit 25A, the drive control unit 12A rotates the vehicle T placed on the support unit 25 by a predetermined rotation angle.

[0037] In the measurement device 10, the antenna 21 is moved to the next measurement position by the drive control of the drive control unit 12A, and the communication performance of the communication system 30 is derived using the second received radio wave 52B of the measurement target radio wave 52A received by the antenna 21 every time the vehicle T placed on the support unit 25 is rotated and driven by a predetermined rotation angle. That is, the measurement device 10 is configured to be able to acquire the second received radio wave 52B received in each region obtained by dividing the outer periphery into a plurality of regions along the outer periphery of a hemisphere C centered on the vehicle T. In other words, the measurement device 10 is configured to be able to acquire the second received radio wave 52B received at each position in all directions of the vehicle T.

[0038] The transmission control unit 12B controls the fixed wave source 40 and the communication system 30 to start and stop transmitting radio waves.

[0039] In detail, the transmission control unit 12B transmits a transmission start signal, which indicates the start of transmission of the first transmission radio wave 50A, to the fixed wave source 40 via the communication unit 14. The fixed wave source 40, which has received the transmission start signal for the first transmission radio wave 50A, starts transmitting the first transmission radio wave 50A wirelessly. In addition, the transmission control unit 12B transmits a transmission stop signal, which indicates the stop of transmission of the first transmission radio wave 50A, to the fixed wave source 40 via the communication unit 14. The fixed wave source 40, which has received the transmission stop signal for the first transmission radio wave 50A, stops transmitting the first transmission radio wave 50A.

[0040] Furthermore, the transmission control unit 12B transmits a transmission start signal, which indicates the start of transmission of the measurement target radio waves 52A, to the communication system 30 via the communication unit 14. The communication system 30, which has received the transmission start signal of the measurement target radio waves 52A, starts wirelessly transmitting the measurement target radio waves 52A. Furthermore, the transmission control unit 12B transmits a transmission stop signal, which indicates the stop of transmission of the measurement target radio waves 52A, to the communication system 30 via the communication unit 14. The communication system 30, which has received the transmission stop signal of the measurement target radio waves 52A, stops transmitting the measurement target radio waves 52A.

[0041] The fixed wave source 40 and the communication system 30 may be configured to switch between starting and stopping the transmission of the first transmitted radio wave 50A and starting and stopping the transmission of the measurement target radio wave 52A in response to an operational instruction by a user. The communication unit 14 may wirelessly transmit a transmission start signal and a transmission stop signal of the first transmitted radio wave 50A to the fixed wave source 40. Similarly, the communication unit 14 may wirelessly transmit a transmission start signal and a transmission stop signal of the measurement target radio wave 52A to the communication system 30. In this case, the transmission control unit 12B may transmit the transmission start signal and the transmission stop signal via the antenna 21, for example.

[0042] The detection unit 12C detects the amplitude of vibration of the antenna 21. The detection unit 12C detects the amplitude of vibration of the antenna 21 based on the radio waves received by the antenna 21.

[0043] The amplitude of the antenna 21 means the amplitude of the antenna 21's swing.

[0044] Vibrations may occur in at least a part constituting the measurement mechanism 20. For example, as described above, in the measurement device 10, the antenna 21 is sequentially moved to the next measurement position by the drive control of the drive control unit 12A. Therefore, vibrations occur in the antenna 21 supported by the measurement mechanism 20 every time the antenna 21 is moved to the next measurement position. For example, vibrations shown in the direction of the arrow S in FIG. 1 may occur in the antenna 21. In addition, vibrations may occur in the antenna 21 due to factors other than the movement of the measurement mechanism 20.

[0045] In this embodiment, the detection unit 12C detects the vibration amplitude of the antenna 21 based on the first received radio wave 50B received by the antenna 21. The first received radio wave 50B is a received radio wave obtained by receiving the first transmitted radio wave 50A transmitted from the fixed wave source 40 by the antenna 21.

[0046] 3 is a schematic diagram of an example of the first received radio wave 50B. The detector 12C calculates the difference Wd between the maximum amplitude Wmax and the minimum amplitude Wmin of the first received radio wave 50B within a predetermined period P as the vibration width of the antenna 21.

[0047] The predetermined period P may be determined by measuring the period from when vibrations occur in antenna 21 due to movement or the like until the vibrations stop a number of times in advance, and using the maximum value of the measured periods as the predetermined period P. The predetermined period P may be changeable by an administrator of measurement mechanism 20 or the like.

[0048] As described above, the first transmitted radio wave 50A transmitted from the fixed wave source 40 is a constant radio wave whose wavelength, period, amplitude, and speed do not change over time. Therefore, when the first transmitted radio wave 50A is received without the antenna 21 vibrating, the first received radio wave 50B, which is the received radio wave of the first transmitted radio wave 50A, does not vary in amplitude. On the other hand, the greater the vibration of the antenna 21, the greater the difference Wd between the maximum amplitude Wmax and the minimum amplitude Wmin of the first received radio wave 50B received by the vibrating antenna 21.

[0049] Therefore, in this embodiment, the detection unit 12C calculates the difference Wd between the maximum amplitude Wmax and the minimum amplitude Wmin within the predetermined period P of the first received radio wave 50B as the vibration width of the antenna 21.

[0050] Returning to FIG. 2, we continue the explanation.

[0051] The derivation unit 12D derives the communication performance of the communication system 30 based on the second received radio wave 52B, which is the measurement target radio wave 52A received by the antenna 21, when the vibration amplitude of the antenna 21 detected by the detection unit 12C is greater than 0 and less than a set amplitude greater than 0.

[0052] In detail, when the oscillation width of the antenna 21 detected by the detection unit 12C is greater than 0 and is equal to or less than a set width according to the frequency of the measurement target radio wave 52A, the derivation unit 12D derives the communication performance of the communication system 30 based on the second received radio wave 52B. In further detail, when the oscillation width of the antenna 21 detected by the detection unit 12C is greater than 0 and is equal to or less than a set width that decreases as the frequency of the measurement target radio wave 52A increases, the derivation unit 12D derives the communication performance based on the second received radio wave 52B.

[0053] Specifically, the set range may be set in advance to a maximum value of the vibration range of antenna 21 that does not affect the derivation of the communication performance of communication system 30. In other words, the set range may be set in advance to a value that is greater than 0 and less than the minimum value of the vibration range of antenna 21 that affects the derivation of the communication performance of communication system 30. As described above, a value that exceeds 0 is set in advance to the set range. That is, a vibration range that represents the vibration of antenna 21 is set in advance as the set range, rather than a state in which antenna 21 does not vibrate at all.

[0054] The set width is preset as an oscillation width according to the frequency of the measurement target radio wave 52A. In detail, the higher the frequency of the measurement target radio wave 52A, the smaller the oscillation width that should be preset as the set width. This is because the higher the frequency of the measurement target radio wave 52A, the higher the measurement accuracy, such as to the millimeter, is required to derive the communication performance of the communication system 30. On the other hand, the lower the frequency of the measurement target radio wave 52A, the larger the oscillation width that should be preset as the set width.

[0055] For example, the derivation unit 12D stores the set width correspondence table 16A in the storage unit 16 in advance.

[0056] The set width correspondence table 16A is a table in which the frequency of the measurement target radio wave 52A is associated with the set width. The data format of the set width correspondence table 16A may be a database or the like, and is not limited to a table.

[0057] The set width correspondence table 16A is a table in which the higher the frequency of the measurement target radio wave 52A, the smaller the set width is associated with it. Also, the set width correspondence table 16A is a table in which the lower the frequency of the measurement target radio wave 52A, the larger the set width is associated with it. Also, the set width correspondence table 16A has set widths that represent values ​​greater than 0 registered in advance.

[0058] The derivation unit 12D acquires, for example, the frequency of the measurement target radio wave 52A transmitted from the communication system 30 from the communication system 30 via the communication unit 14. Note that the derivation unit 12D may acquire the frequency of the measurement target radio wave 52A input by a user's operation instruction from an input unit such as a keyboard.

[0059] The derivation unit 12D reads the set width corresponding to the frequency of the acquired measurement target radio wave 52A from the set width correspondence table 16A, thereby acquiring the set width used for the derivation.

[0060] Then, when the vibration amplitude of the antenna 21 detected by the detection unit 12C is greater than 0 and is equal to or smaller than the acquired set amplitude, the derivation unit 12D acquires the second received radio wave 52B, which is the measurement target radio wave 52A received by the antenna 21. The derivation unit 12D derives the communication performance of the communication system 30 by using the acquired second received radio wave 52B.

[0061] For example, the derivation unit 12D derives, as the communication performance, information that associates information indicating the acquired second received radio wave 52B with position information of the antenna 21 in real space at the time of acquiring the second received radio wave 52B. For the position of the antenna 21 in real space, the position of the antenna 21 on the outer surface of the hemisphere C derived by the control of the drive unit 23A, the drive unit 24A, and the drive unit 25A by the drive control unit 12A may be used.

[0062] The derivation unit 12D may use at least one of the amplitude, wavelength, period, amplitude, and speed of the acquired second received radio wave 52B as information representing the second received radio wave 52B.

[0063] Next, an example of the flow of information processing executed by the measurement device 10 of this embodiment will be described.

[0064] Fig. 4 is a flowchart showing an example of the flow of information processing executed by the measurement device 10. The description will be made on the assumption that the fixed wave source 40 and the communication system 30 are not emitting radio waves immediately before the flowchart shown in Fig. 4 is executed. The description will be made on the assumption that the derivation unit 12D has acquired the frequency of the measurement target radio waves 52A emitted from the communication system 30 before the flowchart shown in Fig. 4 is executed.

[0065] The drive control unit 12A controls the movement of the antenna 21 to the next measurement position (step S100). The drive control unit 12A controls the drive units 23A and 24A to move the position of the antenna 21 on the outer periphery of a hemisphere C (see FIG. 1) centered on the vehicle T to the next measurement position between the apex of the hemisphere C and the peripheral edge of the hemisphere C on the outer periphery.

[0066] The transmission control unit 12B transmits a transmission start signal representing the start of transmission of the first transmission radio wave 50A to the fixed wave source 40 (step S102). Upon receiving the transmission start signal, the fixed wave source 40 starts transmitting the first transmission radio wave 50A.

[0067] The detection unit 12C acquires the first received radio wave 50B, which is the first transmitted radio wave 50A received by the antenna 21 (step S104). The detection unit 12C acquires the first received radio wave 50B from the antenna 21 via the communication unit .

[0068] The detection unit 12C detects the vibration amplitude of the antenna 21 based on the first received radio wave 50B acquired in step S104 (step S106). The detection unit 12C calculates the difference Wd between the maximum amplitude Wmax and the minimum amplitude Wmin within the predetermined period P of the first received radio wave 50B acquired in step S104 as the vibration amplitude of the antenna 21.

[0069] The derivation unit 12D determines whether the vibration amplitude of the antenna 21 detected in step S106 is greater than 0 and equal to or less than the set width (step S108). The derivation unit 12D reads the set width corresponding to the frequency of the measurement target radio wave 52A from the set width correspondence table 16A. Then, the derivation unit 12D determines whether the vibration amplitude of the antenna 21 detected in step S106 is greater than 0 and equal to or less than the read set width.

[0070] When it is determined that the vibration amplitude is a value exceeding the set amplitude (step S108: No), the process returns to step S104. On the other hand, when it is determined that the vibration amplitude is greater than 0 and equal to or less than the set amplitude (step S108: Yes), the process proceeds to step S110. Note that the derivation unit 12D may also make a positive determination in step S108 when it is determined that the vibration amplitude is 0.

[0071] In step S110, the transmission control unit 12B transmits a transmission stop signal representing the stop of transmission of the first transmission radio wave 50A to the fixed wave source 40 (step S110). The fixed wave source 40 that has received the transmission stop signal stops transmission of the first transmission radio wave 50A.

[0072] Next, the transmission control unit 12B transmits a transmission start signal indicating the start of transmission of the measurement target radio wave 52A to the communication system 30 (step S112). The communication system 30 that has received the transmission start signal starts transmitting the measurement target radio wave 52A.

[0073] The derivation unit 12D acquires the second received radio wave 52B, which is the measurement target radio wave 52A received by the antenna 21 (step S114). The derivation unit 12D acquires the second received radio wave 52B from the antenna 21 via the communication unit .

[0074] The derivation unit 12D derives the communication performance of the communication system 30 based on the second received radio wave 52B acquired in step S114 (step S116). Then, the derivation unit 12D stores the communication performance derived in step S116 in the storage unit 16 (step S118).

[0075] Then, the drive control unit 12A controls the drive unit 25A to rotate the vehicle T placed on the support unit 25 by a predetermined rotation angle. Every time the vehicle T is rotated by a predetermined rotation angle, the derivation unit 12D repeats the acquisition of the second received radio wave 52B in step S114, the derivation of the communication performance in step S116, and the storage of the communication performance in step S118 in the storage unit 16 (step S120). Then, when the rotation of the support unit 25 in the circumferential direction by 360° by the rotation by the predetermined rotation angle is completed, the process proceeds to step S122.

[0076] In step S122, the transmission control unit 12B transmits a transmission stop signal representing the stop of transmission of the measurement target radio wave 52A to the communication system 30 (step S122). The communication system 30 that has received the transmission stop signal stops transmission of the measurement target radio wave 52A.

[0077] Next, the processing unit 12 judges whether or not to end the measurement process (step S124). For example, the processing unit 12 makes the judgment in step S124 by determining whether or not the measurement of measurement positions in all directions along the outer periphery of the hemisphere C (see FIG. 1) centered on the vehicle T has been completed. If the judgment in step S124 is negative (step S124: No), the process returns to step S100. If the judgment in step S124 is positive (step S124: Yes), the process ends this routine.

[0078] As described above, the measurement device 10 of this embodiment includes the detection unit 12C and the derivation unit 12D. The detection unit 12C detects the amplitude of the antenna 21 that receives the measurement target radio wave 52A from the vehicle T equipped with the communication system 30 that transmits the measurement target radio wave 52A, based on the first transmitted radio wave 50A received by the antenna 21. When the amplitude is greater than 0 and equal to or less than a set amplitude greater than 0, the derivation unit 12D derives the communication performance of the communication system 30 based on the second received radio wave 52B, which is the measurement target radio wave 52A received by the antenna 21.

[0079] As the object to be measured, such as the vehicle T, becomes larger, a larger measurement mechanism 20 must be used to derive the communication performance of the communication system 30 mounted on the object. However, as the measurement mechanism 20 becomes larger, the influence of vibrations propagated from each part of the measurement mechanism 20 to the antenna 21 becomes stronger. Also, from the viewpoint of suppressing the influence of radio waves, the measurement mechanism 20 may be made of a non-metallic material. In this case, the antenna 21 supported by the measurement mechanism 20 becomes more susceptible to vibration.

[0080] In the conventional technology, the measurement is performed after waiting visually until the vibration of the antenna 21 completely stops. In other words, in the conventional technology, it is difficult to perform a highly accurate measurement while the antenna 21 is vibrating.

[0081] Meanwhile, the detection unit 12C of the measurement device 10 of this embodiment detects the vibration amplitude of the antenna 21 based on the first transmitted radio wave 50A received by the antenna 21. Then, the derivation unit 12D derives the communication performance of the communication system 30 based on the second received radio wave 52B, which is the measurement target radio wave 52A received by the antenna 21, when the vibration amplitude is greater than 0 and equal to or less than a set amplitude greater than 0.

[0082] Since the vibration amplitude of the antenna 21 is detected based on the first transmitted radio wave 50A received by the antenna 21, the measurement device 10 of this embodiment can detect the vibration of the antenna 21 with high accuracy. Furthermore, the measurement device 10 of this embodiment derives the communication performance of the communication system 30 based on the second received radio wave 52B, which is the measurement target radio wave 52A received by the antenna 21, when the detected vibration amplitude is greater than 0 and equal to or less than a set amplitude greater than 0, rather than the vibration amplitude of zero "0" which indicates a state in which the vibration of the antenna 21 has completely stopped. Therefore, the measurement device 10 of this embodiment can derive, i.e., measure, the communication performance of the communication system 30 with high accuracy even if the antenna 21 is vibrating.

[0083] Therefore, the measurement device 10 of this embodiment can measure the communication performance of the communication system 30 with high accuracy.

[0084] In addition, the time required for the vibration of antenna 21 to converge varies depending on the size of measurement mechanism 20, the weight of measurement mechanism 20, the size of antenna 21, and the weight of antenna 21. In the conventional technology, the measurement was performed after waiting visually until the vibration of antenna 21 completely stopped, which required a long time for the measurement.

[0085] On the other hand, the measurement device 10 of this embodiment derives the communication performance of the communication system 30 based on the second received radio wave 52B received by the antenna 21 when the detected vibration amplitude is greater than 0 and equal to or less than a set amplitude greater than 0. Therefore, the measurement device 10 of this embodiment can measure the communication performance of the communication system 30 with high accuracy without waiting until the vibration of the antenna 21 completely stops. Therefore, in addition to the above effects, the measurement device 10 of this embodiment can shorten the measurement time.

[0086] Second embodiment In this embodiment, a form will be described in which, instead of the first transmitted radio wave 50A received from the fixed wave source 40, a received radio wave reflected from a vehicle T is used as the first received radio wave used to detect the vibration amplitude of the antenna 21.

[0087] In this embodiment, parts having the same functions or configurations as those in the above embodiment are given the same reference numerals and detailed description thereof will be omitted.

[0088] 5 is a schematic diagram showing an example of a measurement system 2 of this embodiment. The measurement system 2 includes a measurement device 11 and a measurement mechanism 20. The measurement system 2 is similar to the measurement system 1 of the above embodiment, except that the measurement system 2 includes the measurement device 11 instead of the measurement device 10 and does not include the fixed wave source 40.

[0089] The measurement device 11 is a device that measures the communication performance of the communication system 30 based on the second received radio waves 52B. The second received radio waves 52B are measurement target radio waves 52A of the communication system 30 received by the antenna 21. In this embodiment, the measurement device 11 detects the vibration amplitude of the antenna 21 by using the first received radio waves 54B, which are reflected waves by the vehicle T of the vibration detection radio waves 54A transmitted from the antenna 21 to the vehicle T.

[0090] Fig. 6 is a functional block diagram of an example of the measurement device 11. Fig. 6 also shows electrical components other than the measurement device 11 included in the measurement system 2.

[0091] The measuring device 11 includes a processing unit 13, a communication unit 14, a storage unit 16, and an output unit 18. The processing unit 13, the communication unit 14, the storage unit 16, and the output unit 18 are communicatively connected, for example, via a bus 19. The communication unit 14, the storage unit 16, and the output unit 18 are similar to those in the above embodiment.

[0092] The processing unit 13 executes various information processing. In this embodiment, the processing unit 13 includes a drive control unit 12A, a transmission control unit 13B, a detection unit 13C, and a derivation unit 12D. A part or all of the drive control unit 12A, the transmission control unit 13B, the detection unit 13C, and the derivation unit 12D may be realized by, for example, having a processing device such as a CPU execute a program, that is, by software, or by hardware such as an IC, or by using both software and hardware. In addition, at least one of the drive control unit 12A, the transmission control unit 13B, the detection unit 13C, and the derivation unit 12D may be mounted on an external information processing device communicatively connected to the measuring device 11 via a network or the like.

[0093] The transmission control unit 13B controls the start and stop of transmission of radio waves from the communication system 30.

[0094] The transmission control unit 13B transmits a transmission start signal, which indicates the start of transmission of the measurement target radio waves 52A, to the communication system 30 via the communication unit 14. The communication system 30, which has received the transmission start signal of the measurement target radio waves 52A, starts wirelessly transmitting the measurement target radio waves 52A. In addition, the transmission control unit 13B transmits a transmission stop signal, which indicates the stop of transmission of the measurement target radio waves 52A, to the communication system 30 via the communication unit 14. The communication system 30, which has received the transmission stop signal of the measurement target radio waves 52A, stops transmitting the measurement target radio waves 52A.

[0095] Furthermore, the transmission control unit 13B causes the antenna 21 to transmit the vibration detection radio waves 54A.

[0096] The vibration detection radio waves 54A are radio waves used to detect vibration of the antenna 21. In this embodiment, an embodiment in which the vibration detection radio waves 54A are modulated waves will be described as an example. For example, the transmission control unit 13B outputs a transmission signal of the vibration detection radio waves 54A, which represents a pulse wave of a predetermined specific frequency, to the antenna 21 via the communication unit 14. When the antenna 21 receives the transmission signal from the transmission control unit 13B via the communication unit 14, it starts transmitting the vibration detection radio waves 54A represented by the transmission signal.

[0097] The detection unit 13C detects the vibration amplitude of the antenna 21. The detection unit 13C detects the vibration amplitude of the antenna 21 based on the radio waves received by the antenna 21.

[0098] In this embodiment, the detection unit 12C detects the vibration amplitude of the antenna 21 based on the first received radio wave 54B received by the antenna 21. The first received radio wave 54B is a received radio wave that is a reflected wave of the vibration detection radio wave 54A transmitted from the antenna 21 and reflected by the vehicle T and received by the antenna 21. That is, the antenna 21 receives the first received radio wave 54B, which is a reflected wave of the first received radio wave 54B by the vehicle T. The detection unit 12C detects the vibration amplitude of the antenna 21 based on the first received radio wave 54B.

[0099] FIG. 7 is an explanatory diagram of an example of detection of the vibration amplitude of the antenna 21 by the detection unit 12C.

[0100] The detector 12C calculates the distance R between the antenna 21 and the vehicle T based on the vibration detection radio waves 54A and the first received radio waves 54B.

[0101] For example, the detection unit 12C derives the time from the transmission of the vibration detection radio wave 54A to the reception of the first received radio wave 54B, which is a reflected wave of the vibration detection radio wave 54A, using a known time domain method, etc. Then, the detection unit 12C calculates the distance R using the time from the transmission of the vibration detection radio wave 54A to the reception of the first received radio wave 54B, which is a reflected wave of the vibration detection radio wave 54A, and the speed of the radio wave.

[0102] The transmission control unit 13B may transmit a modulated wave by FMCW (frequency continuous modulation) from the antenna 21 as the vibration detection radio wave 54A. In this case, the detection unit 12C generates an IF (Intermediate Frequency) signal from the vibration detection radio wave 54A and the first received radio wave 54B, and performs known signal processing on the IF signal to calculate the distance R. For example, the detection unit 12C converts the IF signal into an analog-to-digital (AD) signal, and further performs a Fourier transform (FFT) to derive a frequency spectrum. The detection unit 12C then calculates the distance R from the derived frequency spectrum.

[0103] Furthermore, the detection unit 12C may calculate the distance R between the antenna 21 and the vehicle T based on the difference between the intensity of the vibration detection radio wave 54A and the intensity of the first received radio wave 54B. For example, the detection unit 12C may previously associate the distance R corresponding to the difference between the amplitude intensity of the vibration detection radio wave 54A and the amplitude intensity of the first received radio wave 54B with each other and store the distance R in the storage unit 16. Then, the detection unit 12C may derive the distance R by reading the distance R corresponding to the difference between the amplitude intensity of the vibration detection radio wave 54A and the amplitude intensity of the first received radio wave 54B from the storage unit 16.

[0104] Then, the detection unit 12C calculates the difference between the calculated distance R between the antenna 21 and the vehicle T and the set distance R'. The set distance R' is the set distance between the assumed position of the antenna 21 in real space and the vehicle T. The assumed position of the antenna 21 in real space may be the position on the outer surface of the hemisphere C of the antenna 21 derived by the control of the drive units 23A, 24A, and 25A by the drive control unit 12A. Moreover, the position of the vehicle T may be calculated in advance and used taking into account the size of the vehicle T on the support unit 25.

[0105] When antenna 21 does not vibrate, distance R and set distance R' have the same value. However, as shown in Fig. 7, for example, when antenna 21 vibrates between the position of antenna 21A and the position of antenna 21B, distance R and set distance R' have different values.

[0106] The detection unit 12C associates the difference between the distance R and the set distance R' with an oscillation amplitude that indicates at least one of the swing angle θ and the swing amount W' of the antenna 21 in advance and stores them in the storage unit 16. Then, the detection unit 12C reads the oscillation amplitude that corresponds to the difference between the distance R and the set distance R' from the storage unit 16, thereby detecting the oscillation amplitude that indicates at least one of the swing angle θ and the swing amount W' of the antenna 21.

[0107] The detection unit 12C may calculate the vibration amplitude from the difference between the distance R and the set distance R'. In this case, for example, the detection unit 12C may calculate the vibration amplitude that represents at least one of the swing angle θ and the swing amount W' of the antenna 21 by a trigonometric function using the distance R and the set distance R'.

[0108] The detection unit 12C may calculate the vibration amplitude of the antenna 21 from the transition of the distance R between the antenna 21 and the vehicle T during a set period, which is calculated from the phase shift between the vibration detection radio waves 54A and the first received radio waves 54B. For example, the detection unit 12C may calculate the difference between the maximum distance R and the minimum distance R during the set period as the vibration amplitude of the antenna 21.

[0109] Returning to Fig. 6, the description will be continued. The derivation unit 12D is the same as in the above embodiment. In this embodiment, the derivation unit 12D may derive the communication performance of the communication system 30 based on the second received radio wave 52B received by the antenna 21 when the vibration amplitude of the antenna 21 detected by the detection unit 13C instead of the detection unit 12C becomes greater than 0 and equal to or less than a set amplitude greater than 0.

[0110] Next, an example of the flow of information processing executed by the measuring device 11 of this embodiment will be described.

[0111] Fig. 8 is a flowchart showing an example of the flow of information processing executed by the measuring device 11. The following description will be made on the assumption that the antenna 21 and the communication system 30 are not transmitting radio waves immediately before the flowchart shown in Fig. 8 is executed. The following description will be made on the assumption that the derivation unit 12D has acquired the frequency of the measurement target radio waves 52A transmitted from the communication system 30 before the flowchart shown in Fig. 8 is executed.

[0112] The drive control unit 12A controls the movement of the antenna 21 to the next measurement position (step S200). The drive control unit 12A controls the drive units 23A and 24A to move the position of the antenna 21 on the outer periphery of a hemisphere C (see FIG. 5) centered on the vehicle T to the next measurement position between the apex of the hemisphere C and the peripheral edge of the hemisphere C on the outer periphery.

[0113] The transmission control unit 13B outputs a transmission signal of the vibration detection radio waves 54A to the antenna 21 via the communication unit 14 (step S202). The antenna 21 that has received the transmission signal of the vibration detection radio waves 54A starts transmitting the vibration detection radio waves 54A.

[0114] The detection unit 13C acquires the first received radio wave 54B, which is the vibration detection radio wave 54A received by the antenna 21 and reflected by the vehicle T (step S204). The detection unit 13C acquires the first received radio wave 54B from the antenna 21 via the communication unit 14.

[0115] The detection unit 13C detects the vibration amplitude of the antenna 21 based on the first received radio wave 54B acquired in step S204 (step S206).

[0116] The derivation unit 12D determines whether the vibration width of the antenna 21 detected in step S206 is equal to or smaller than the set width (step S208). The derivation unit 12D reads the set width corresponding to the frequency of the measurement target radio wave 52A from the set width correspondence table 16A. Then, the derivation unit 12D determines whether the vibration width of the antenna 21 detected in step S206 is equal to or smaller than the read set width.

[0117] If it is determined that the vibration amplitude exceeds the set amplitude (step S208: No), the process returns to step S204. On the other hand, if it is determined that the vibration amplitude is equal to or smaller than the set amplitude (step S208: Yes), the process proceeds to step S210.

[0118] In step S210, the transmission control unit 13B stops transmitting the transmission signal of the vibration detection radio waves 54A to the antenna 21 (step S210). The antenna 21, for which the transmission of the transmission signal of the vibration detection radio waves 54A has been stopped, stops transmitting the vibration detection radio waves 54A.

[0119] Next, the transmission control unit 13B transmits a transmission start signal indicating the start of transmission of the measurement target radio wave 52A to the communication system 30 (step S212). The communication system 30 that has received the transmission start signal starts transmitting the measurement target radio wave 52A.

[0120] The derivation unit 12D acquires the second received radio wave 52B, which is the measurement target radio wave 52A received by the antenna 21 (step S214). The derivation unit 12D acquires the second received radio wave 52B from the antenna 21 via the communication unit .

[0121] The derivation unit 12D derives the communication performance of the communication system 30 based on the second received radio wave 52B acquired in step S214 (step S216). Then, the derivation unit 12D stores the communication performance derived in step S216 in the storage unit 16 (step S218).

[0122] Then, the drive control unit 12A controls the drive unit 25A to rotate the vehicle T placed on the support unit 25 by a predetermined rotation angle. Every time the vehicle T is rotated by a predetermined rotation angle, the derivation unit 12D repeats the acquisition of the second received radio wave 52B in step S214, the derivation of the communication performance in step S216, and the storage of the communication performance in step S218 in the storage unit 16 (step S220). Then, when the rotation of the support unit 25 by the predetermined rotation angle completes 360° in the circumferential direction, the process proceeds to step S222.

[0123] In step S222, the transmission control unit 13B transmits a transmission stop signal representing the stop of transmission of the measurement target radio wave 52A to the communication system 30 (step S222). The communication system 30 that has received the transmission stop signal stops transmission of the measurement target radio wave 52A.

[0124] Next, the processing unit 13 judges whether or not to end the measurement process (step S224). For example, the processing unit 13 makes the judgment in step S224 by determining whether or not the measurement of the measurement positions in all directions along the outer periphery of the hemisphere C (see FIG. 5) centered on the vehicle T has been completed. If the judgment in step S224 is negative (step S224: No), the process returns to step S200. If the judgment in step S224 is positive (step S224: Yes), the process ends this routine.

[0125] As described above, the detection unit 13C of the measurement device 11 of this embodiment detects the vibration amplitude of the antenna 21 based on the first received radio wave 54B, which is a wave reflected by the vehicle T of the vibration detection radio wave 54A transmitted from the antenna 21 to the vehicle T. That is, the detection unit 13C of this embodiment detects the vibration amplitude of the antenna 21 based on a phase shift between the vibration detection radio wave 54A and the first received radio wave 54B, etc. Then, when the vibration amplitude becomes equal to or less than a set amplitude larger than 0, the derivation unit 12D derives the communication performance of the communication system 30 based on the second received radio wave 52B, which is the measurement target radio wave 52A received by the antenna 21.

[0126] Therefore, the measurement device 11 of this embodiment can measure the communication performance of the communication system 30 with high accuracy even when the antenna 21 is shaking, similar to the above embodiment.

[0127] Furthermore, the measuring device 11 of this embodiment detects the vibration amplitude of the antenna 21 based on the first received radio wave 54B, which is a reflected wave by the vehicle T of the vibration detection radio wave 54A transmitted from the antenna 21 to the vehicle T. Therefore, the measuring device 11 of this embodiment can detect the vibration amplitude of the antenna 21 without providing a separate device for measuring the vibration of the antenna 21, such as an acceleration sensor.

[0128] Therefore, in addition to the above-mentioned effects, the measuring device 11 of this embodiment can suppress the device from becoming complicated.

[0129] Next, an example of the hardware configuration of the measurement device 10 and the measurement device 11 of the above embodiment will be described.

[0130] FIG. 9 is a diagram showing an example of a hardware configuration of the measurement device 10 and the measurement device 11 of the above embodiment.

[0131] The measuring device 10 and the measuring device 11 of the above embodiments are equipped with a control device such as a CPU 60A, storage devices such as a ROM (Read Only Memory) 60B, a RAM (Random Access Memory) 60C, and a HDD (Hard Disk Drive), an I / F section 60D that interfaces with various devices, and a bus 60E that connects each section, and are configured as hardware using a normal computer.

[0132] In the measuring device 10 and the measuring device 11 of the above-described embodiments, the CPU 60A reads a program from the ROM 60B onto the RAM 60C and executes it, thereby realizing each of the above-described units on the computer.

[0133] The programs for executing the above-mentioned processes executed by the measuring device 10 and the measuring device 11 of the above-mentioned embodiment may be stored in the HDD. Also, the programs for executing the above-mentioned processes executed by the measuring device 10 and the measuring device 11 of the above-mentioned embodiment may be provided by being pre-installed in the ROM 60B.

[0134] The programs for executing the above processes executed by the measuring device 10 and the measuring device 11 of the above embodiment may be stored in a computer-readable storage medium such as a CD-ROM, a CD-R, a memory card, a DVD (Digital Versatile Disk), or a flexible disk (FD) in an installable or executable format file and provided as a computer program product. The programs for executing the above processes executed by the measuring device 10 and the measuring device 11 of the above embodiment may be stored on a computer connected to a network such as the Internet and provided by downloading the programs via the network. The programs for executing the above processes executed by the measuring device 10 and the measuring device 11 of the above embodiment may be provided or distributed via a network such as the Internet.

[0135] Although the embodiment of the present invention has been described above, the embodiment is presented as an example and is not intended to limit the scope of the invention. This new embodiment can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. This embodiment and its modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0136] 10, 11 Measuring device 12A Drive control unit 12B, 13B Transmission control section 12C, 13C Detector 12D Derivation part 21 Antenna 30 Communication Systems 40 Fixed wave source

Claims

1. A transmission control unit that transmits vibration detection radio waves from an antenna; a detection unit that detects, as the vibration amplitude of the antenna, at least one of a swing angle and a swing amount of the antenna corresponding to a difference between a distance between the antenna and the target derived based on a first received radio wave, which is a reflected wave of the vibration detection radio wave received by the antenna from the target equipped with a communication system that transmits the measurement target radio wave, and a set distance between the antenna and the target; a derivation unit that derives communication performance of the communication system based on a second received radio wave, which is the measurement target radio wave received by the antenna, when the oscillation width is greater than 0 and is equal to or smaller than a set width greater than 0; A measuring device comprising:

2. The lead-out portion is When the oscillation width is greater than 0 and is equal to or smaller than the set width corresponding to the frequency of the measurement target radio wave, the communication performance is derived based on the second received radio wave.

2. The measuring device of claim 1.

3. The lead-out portion is When the oscillation width is greater than 0 and is equal to or smaller than the set width, the set width decreasing as the frequency of the measurement target radio wave increases, the communication performance is derived based on the second received radio wave. The measuring device according to claim 1 or 2.

4. A step of transmitting vibration detection radio waves from an antenna; a step of detecting, as the vibration amplitude of the antenna receiving the radio wave to be measured from an object equipped with a communication system that transmits the radio wave to be measured, at least one of a swing angle and a swing amount of the antenna corresponding to a difference between a distance between the antenna and the object derived based on a first received radio wave, which is a reflected wave of the vibration detection radio wave received by the antenna by the object, and the vibration detection radio wave, and a set distance between the antenna and the object; When the oscillation width is greater than 0 and is equal to or smaller than a set width greater than 0, deriving a communication performance of the communication system based on a second received radio wave, which is the measurement target radio wave received by the antenna; Measurement methods including:

5. The deriving step comprises: When the oscillation width is greater than 0 and is equal to or smaller than the set width corresponding to the frequency of the measurement target radio wave, the communication performance is derived based on the second received radio wave. The measurement method according to claim 4.

6. The deriving step comprises: When the oscillation width is greater than 0 and is equal to or smaller than the set width, the set width decreasing as the frequency of the measurement target radio wave increases, the communication performance is derived based on the second received radio wave. The measurement method according to claim 4 or 5.

7. A step of transmitting a vibration detection radio wave from an antenna; a step of detecting, as the vibration amplitude of the antenna receiving the radio wave to be measured from an object equipped with a communication system that transmits the radio wave to be measured, at least one of a swing angle and a swing amount of the antenna corresponding to a difference between a distance between the antenna and the object derived based on a first received radio wave, which is a reflected wave of the vibration detection radio wave received by the antenna by the object, and the vibration detection radio wave, and a set distance between the antenna and the object; When the oscillation width is greater than 0 and is equal to or smaller than a set width greater than 0, deriving a communication performance of the communication system based on a second received radio wave, which is the measurement target radio wave received by the antenna; A measurement program for causing a computer to execute the above.

8. The deriving step comprises: When the oscillation width is greater than 0 and is equal to or smaller than the set width corresponding to the frequency of the measurement target radio wave, the communication performance is derived based on the second received radio wave. The measurement program according to claim 7.

Images