WO2024075180A1

WO2024075180A1 - Propagation environment reproduction device, propagation environment reproduction method, and propagation environment reproduction system

Info

Publication number: WO2024075180A1
Application number: PCT/JP2022/037145
Authority: WO
Inventors: 諒太郎谷口; 友規村上; 智明小川; 泰司鷹取
Original assignee: 日本電信電話株式会社
Priority date: 2022-10-04
Filing date: 2022-10-04
Publication date: 2024-04-11

Abstract

This disclosure relates to a propagation environment reproduction device that reproduces a propagation environment for verifying the communication performance and the like of an object of measurement. The device comprises: an electromagnetic anechoic chamber 10 that blocks electromagnetic waves from the outside; reconfigurable intelligent surfaces (RISs) 16 installed in the electromagnetic anechoic chamber 10; an RIS control device 22 that provides control signals to the RISs 16; transmitting antennas 20 installed in the electromagnetic anechoic chamber 10; a channel emulator 24 that controls the characteristics of electromagnetic waves transmitted from the transmitting antennas 20; and a control server 26 that controls the RIS control device 22 and the channel emulator 24. The RISs 16 are reflective plates having the characteristic of changing the reflection pattern in response to the control signals.

Description

Propagation environment reproducing device, propagation environment reproducing method, and propagation environment reproducing system

This disclosure relates to a propagation environment reproducing device, a propagation environment reproducing method, and a propagation environment reproducing system, and in particular to a propagation environment reproducing device, a propagation environment reproducing method, and a propagation environment reproducing system that are suitable for reproducing a propagation environment to verify the communication performance, etc., of an object to be measured.

The following non-patent document 1 discloses technology related to OTA (Over The Air) testing, which uses equipment used for wireless communication as the measurement object to verify its performance and quality. In OTA testing, one or more transmitting antennas are placed in an anechoic chamber or shielded room to recreate an environment within that space that exhibits the same propagation characteristics as the real space.

If you measure the communication quality of the object in a propagation environment that reproduces the propagation characteristics that occur in real space, you can measure the communication quality that is demonstrated in real space. Therefore, by using OTA techniques, you can easily and accurately evaluate the performance of devices used for wireless communication.

The biggest challenge in carrying out OTA testing is how to accurately reproduce the desired radio propagation environment that occurs in real space. On the other hand, a reflector called a Reconfigurable Intelligent Surface (RIS) is known as a device that controls the reflection of radio waves.

RIS is a tunable reflector that uses metamaterial technology. Metamaterials refers to artificially changing the properties of a material, and with this technology, for example, it is possible to create a phenomenon in which the refractive index of electromagnetic waves becomes negative.

This disclosure has been made in consideration of the above problems, and has as its first objective to provide a propagation environment reproducing device that accurately reproduces a desired wireless propagation environment by placing a RIS in a space such as an anechoic chamber and simultaneously controlling the direction and intensity of reflection of electromagnetic waves by the RIS.

A second object of the present disclosure is to provide a method for reproducing a propagation environment by placing a RIS in a space such as an anechoic chamber and simultaneously controlling the direction and intensity of reflection of electromagnetic waves by the RIS, thereby accurately reproducing a desired wireless propagation environment.

A third object of the present disclosure is to provide a propagation environment reproduction system that accurately reproduces a desired wireless propagation environment by placing a RIS in a space such as an anechoic chamber and simultaneously controlling the direction and intensity of reflection of electromagnetic waves by the RIS.

In order to achieve the above object, a first aspect is a propagation environment reproducing device, comprising:
A Reconfigurable Intelligent Surface (RIS) is installed in a space that reproduces the electromagnetic wave propagation environment.
a RIS controller for providing control signals to the RIS;
A transmitting antenna installed in the propagation environment reproduction space;
a channel emulator for controlling the characteristics of the electromagnetic wave transmitted from the transmitting antenna;
a control server for controlling the RIS control device and the channel emulator;
The RIS is preferably a reflector having a characteristic of changing its reflection pattern in response to the control signal.

A second aspect is a propagation environment reproduction method for reproducing a desired propagation environment using a RIS installed in a propagation environment reproduction space for reproducing an electromagnetic wave propagation environment and a transmission antenna installed in the propagation environment reproduction space, comprising:
The RIS is a reflector having a characteristic of changing a reflection pattern in response to a control signal,
Calculating, by simulation, propagation characteristics generated in the propagation environment reproduction space under each parameter while changing parameters related to the propagation environment reproduction space, the RIS, and the transmitting antenna;
providing a propagation environment model with a combination of actual characteristics, which are propagation characteristics actually measured at a measurement position in a real space, and reproduction parameters, which are parameters calculated to generate propagation characteristics identical to the actual characteristics in the propagation environment reproduction space, as teacher data, to create a learning model that derives parameters to generate the propagation characteristics in the propagation environment reproduction space when a propagation characteristic to be reproduced is given;
providing desired propagation characteristics to the learning model to cause the learning model to derive parameters for generating the desired propagation characteristics;
constructing the propagation environment reproduction space according to the parameters derived by the learning model;
Arranging the RIS and the transmitting antenna in the propagation environment reproduction space according to the parameters derived by the learning model;
Controlling the RIS so that the RIS exhibits a reflex pattern represented by the parameters derived by the learning model;
Controlling a transmission signal from the transmitting antenna so that the transmitting antenna transmits electromagnetic waves with characteristics indicated by parameters derived by the learning model;
It is preferable that the present invention includes the following:

A third aspect is a propagation environment reproduction system, comprising:
The RIS was installed in a space that reproduced the electromagnetic wave propagation environment,
A transmitting antenna installed in the propagation environment reproduction space,
The RIS is a reflector having a characteristic of changing a reflection pattern in response to a control signal,
the propagation environment reproduction space is configured according to specifications indicated by parameters set to reproduce desired characteristics, which are propagation characteristics occurring at a measurement position in a real space;
The RIS and the transmitting antenna are arranged according to the specifications indicated by the parameters,
a function of controlling the RIS so that the RIS exhibits a reflection pattern indicated by the parameters;
a function of controlling a transmission signal from the transmitting antenna so that the transmitting antenna transmits electromagnetic waves with characteristics indicated by the parameters;
It is preferable that the optical fiber 100 is configured to have the following characteristics:

According to the first to third aspects, the desired radio propagation environment can be accurately reproduced by simultaneously controlling the reflection direction and reflection intensity of the electromagnetic waves by the RIS.

1 is a diagram showing an overall configuration of a propagation environment reproduction device according to a first embodiment of the present disclosure; 4 is a flowchart for explaining a procedure for deriving parameters for reproducing a desired propagation environment by the propagation environment reproduction device shown in FIG. 1 . FIG. 1 is a diagram for explaining one of the typical characteristics that can be imparted to a RIS. FIG. 13 is a diagram for explaining other typical characteristics that can be imparted to the RIS. FIG. 1 is a diagram showing reflections occurring in a normal room. FIG. 13 is a diagram for explaining a limit imposed by a RIS for controlling reflected power. 1A to 1C are diagrams for explaining characteristics of reflection by a RIS that controls the reflection direction. 1 is a diagram showing how the device according to the first embodiment of the present disclosure uses a RIS that controls the reflection direction to control reflected power at the same time as the reflection direction. 1 is a diagram showing how the device of the first embodiment of the present disclosure absorbs and eliminates unnecessary reflected signals from a RIS using an absorber. FIG. 2 is a diagram for explaining a hardware configuration of a control server provided in an apparatus according to a first embodiment of the present disclosure. FIG. 1 is a flowchart for explaining a flow when evaluating communication performance, etc. of a measuring object using an apparatus according to an embodiment of the present disclosure.

Embodiment 1.
[Configuration of First Embodiment]
1 is a diagram showing an overall configuration of a propagation environment reproducing device according to a first embodiment of the present disclosure. The propagation environment reproducing device according to the present embodiment includes an anechoic chamber 10. The anechoic chamber 10 is a chamber capable of blocking the influence of electromagnetic waves from the outside, and may also be called a shielded room or a reverberation chamber. In the present embodiment, the anechoic chamber 10 is used for the purpose of reproducing within itself a desired propagation environment for a wireless signal, more specifically, a real propagation environment occurring in a real space such as a city street.

The object to be measured 12 is placed in the anechoic chamber 10. The object to be measured 12 is, for example, a mobile terminal equipped with multiple antennas to achieve MIMO functionality. In the example shown in FIG. 1, the object to be measured 12 is placed on a stand 14. The stand 14 is used to hold the object to be measured 12 in a desired space within the anechoic chamber 10. In real spaces such as city streets, a situation may arise in which a mobile terminal or the like is mounted on a drone and positioned in the air. By using the stand 14, the object to be measured 12 can be held in a position within the anechoic chamber 10 that corresponds to the air in real space.

Multiple RISs 16 are placed inside the anechoic chamber 10. The RISs 16 can be installed on the walls, ceiling, or floor of the anechoic chamber 10. The RISs 16 can also be placed in the air inside the anechoic chamber 10 by supporting them with a jig installed on the floor or by hanging them from the ceiling (not shown).

A radio wave absorber 18 can be placed anywhere in the anechoic chamber 10. The radio wave absorber 18 has the function of absorbing irradiated electromagnetic waves. The radio wave absorber 18 can eliminate radio waves inside the anechoic chamber 10 that are unnecessary for simulating a propagation environment in a real space.

One or more transmitting antennas 20 are arranged in the anechoic chamber 10. The positions of the transmitting antennas 20 can be determined arbitrarily. Figure 1 shows an example in which three transmitting antennas 20 are arranged inside the anechoic chamber 10.

A RIS control device 22 is connected to the RIS 16. In this embodiment, all RIS 16 are provided with a function for varying the reflection direction of the electromagnetic waves, or more specifically, the reflection pattern of the electromagnetic waves. The RIS control device 22 provides a control signal to each of the RIS 16. Each of the RIS 16 changes its reflection pattern in response to the received control signal. Therefore, in this embodiment, it is possible to cause each of the RIS 16 installed in the anechoic chamber 10 to form a desired reflection pattern.

A channel emulator 24 is connected to the transmitting antenna 20. The channel emulator has a function of controlling the characteristics of the electromagnetic waves transmitted from the transmitting antenna 20. Specifically, the channel emulator 24 can control the radiation direction, power, radiation timing, etc. of the electromagnetic waves transmitted from the transmitting antenna 20.

A control server 26 is connected to the RIS control device 22 and the channel emulator 24. The control server 26 controls the RIS control device 22 and the channel emulator 24 so that the desired propagation environment is reproduced at the position of the receiving antenna provided on the object to be measured 12. By appropriately setting the specifications of the propagation environment reproduction device and appropriately controlling the RIS control device 22 and the channel emulator 24, respectively, it is possible to reproduce the desired propagation environment inside the anechoic chamber 10, particularly at the position of the object to be measured 12.

The configuration shown in FIG. 1 is an example of one form of a propagation environment reproduction device. The shape and size of the anechoic chamber 10 can be changed. The shape can be, for example, a sphere, an n-hedron (n is an integer), an n-sided prism, an n-sided pyramid, etc. Any number of RIS 16 and transmitting antennas 20 greater than or equal to one can be placed, and the placement positions can also be arbitrary.

[Method of deriving reproduction parameters]
FIG. 2 is a flowchart for explaining a procedure for deriving parameters for reproducing a desired propagation environment by the propagation environment reproducing device shown in FIG.

First, various parameters related to the characteristics of the propagation environment reproduction device are changed in various ways, and the propagation characteristics generated in the anechoic chamber 10 under each combination of parameters are calculated by simulation (step 100). The type of simulation may be, for example, ray tracing (ray launching method), ray tracing (imaging method), electromagnetic field analysis (FDTD method), etc.

The parameters to be set include, for example, the following:
The shape, size and material of the anechoic chamber 10 The shape, size, number, arrangement, controllable angle and controllable reflectance of the RIS 16 The location, number and characteristics of the transmitted signal of the transmitting antennas 20 The location, number and characteristics of the received signal of the receiving antennas The direction of the transmitted beam The position, size, number and shape of the radio wave absorber

The propagation characteristics are the characteristics of the electromagnetic wave at the receiving point, and specifically, the following physical quantities are included:
・Received power ・XPR (Cross Polarization Ratio, vertical-horizontal power ratio)
- Delay time - Direction of arrival (horizontal/vertical)
- Delay spread - Angular spread - Number of clusters that make up the radio wave mass

Once the processing of step 100 above is completed, the propagation characteristics that are actually generated in the real space (hereinafter referred to as "actual characteristics") are identified. In addition, parameters that produce the actual characteristics in the anechoic chamber 10 (hereinafter referred to as "reproduced parameters") are identified based on the results of the simulation above. By repeating this processing, multiple sets of actual characteristics and parameters are prepared (step 102).

The above "actual characteristics" are the propagation characteristics that are actually measured at the position of the measurement object 12, which is an actual device placed in a real space such as a city center. The "reproduction parameters" are parameters obtained by simulation to generate the "actual characteristics" inside the anechoic chamber 10. Therefore, if a propagation environment reproduction device is prepared according to the reproduction parameters, the same characteristics as the above "actual characteristics" should be generated inside it.

The set of "actual characteristics" and "reproduced parameters" is used as training data for machine learning. In other words, in this embodiment, the multiple data sets prepared in step 102 above are provided to the propagation environment model as training data for machine learning. Then, by repeating learning using a large amount of training data, when an actual characteristic is given, a learning model is created that derives parameters that will generate that characteristic within the anechoic chamber 10 (step 104).

Once the learning model has been created, the propagation characteristics to be reproduced within the anechoic chamber 10 (hereinafter referred to as the "desired characteristics") are provided to the learning model (step 106).

As a result, parameters for generating the desired characteristics within the anechoic chamber 10 are derived from the learning model (step 108).

After that, a propagation environment reproducing device is prepared according to the parameters derived in step 108 above, and electromagnetic waves are sent into it. This reproduces the desired characteristics in the anechoic chamber 10 at the position of the measurement object 12 (step 110).

Once the desired characteristics have been reproduced, the communication performance, communication quality, etc. of the measurement object 12 placed in the anechoic chamber 10 are measured, and the results are evaluated (step 112).

As described above, the propagation environment reproducing device of this embodiment can reproduce the desired characteristics in the anechoic chamber 10 and evaluate the object to be measured 12. Therefore, this device can accurately evaluate the capabilities of the object to be measured 12 in real space without performing measurements in real space.

[RIS characteristics]
3A is a diagram for explaining an example of a property that can be imparted to a RIS using metamaterial technology. As shown in FIG. 3A, the RIS can be given a property that changes the direction in which it reflects an incident wave in response to a control signal provided from a controller.

Figure 3B shows other typical properties that can be given to a RIS. As shown in Figure 3B, a RIS can be given the property of transmitting an incident wave, the property of concentrating a reflected wave at a specific location, the property of absorbing part of the incident wave and reflecting it with a reduced intensity, and the property of scattering the incident wave. Depending on the type of structure adopted, a RIS can be selectively given the properties shown in Figure 3B in addition to the properties shown in Figure 3A.

The RIS 16 used in this embodiment has the characteristic shown in FIG. 3A, that is, the characteristic of varying the direction of the reflected wave. More specifically, the RIS 16 in this embodiment has the characteristic of varying the reflection pattern in response to a control signal.

Figure 4A shows how reflections occur in a normal room. In this case, the electromagnetic waves emitted from the transmitting antenna 20 are reflected by the wall surface and change direction. The angle of incidence of the electromagnetic waves on the wall surface is the same as the angle of reflection of the electromagnetic waves on the wall surface. Furthermore, power 1 after reflection is maintained approximately equal to transmission power 1.

FIG. 4B shows the state of reflection when a RIS with a characteristic of varying the reflected power is placed on the wall of the anechoic chamber 10. Path 28 shown in FIG. 4B shows the desired path for making the electromagnetic wave incident on the receiving point where the object to be measured 12 is placed. Meanwhile, path 30 shows the path that actually occurs in this example. The RIS shown in FIG. 4B reflects the electromagnetic wave at the same reflection angle as in the case shown in FIG. 4A. Therefore, if the position of the transmitting antenna 20 and the position of the object to be measured 12 are not symmetrically placed on either side of the RIS, the reflected electromagnetic wave will not reach the object to be measured 12. In this way, with a RIS with a variable reflected power, although it is possible to control the power after reflection, a situation may occur in which the reflected wave generated as a result cannot reach the object to be measured 12. In other words, with a RIS with such characteristics, it is impossible to make the reflected wave with the desired power travel in the desired direction.

FIG. 5 is a diagram for explaining in detail the reflection characteristics of the RIS 16 used in this embodiment. As described above, the RIS 16 is given the characteristic of varying the reflection direction according to a control signal. FIG. 5 shows an example of a reflection pattern formed by giving a specific control signal to the RIS 16. Here, the largest reflection occurs in the reflection direction of path 32. Also, attenuated reflection occurs in the direction of path 34. The reflection pattern of the RIS 16 changes according to the control signal. Therefore, if a receiving antenna exists in the direction of path 34, and a reflection pattern is created in which the reflection in the direction of path 34 has the desired power, it becomes possible for the RIS 16 to control both the direction and strength of the reflection.

[Example of control of reflection direction and reflection intensity]
Fig. 6A shows an example of the state in which the RIS 16 simultaneously controls the reflection direction and reflected power of the electromagnetic wave transmitted from the transmitting antenna 20. Here, an electromagnetic wave with a power of 1 is transmitted from the transmitting antenna to the RIS 16, and the RIS 16 reflects an electromagnetic wave with a power of 0.5 in the incident direction toward the object to be measured 12. In this way, if the reflection pattern shown in Fig. 6A is generated in the RIS 16, a reflected wave with half the power can be made to enter the object to be measured 12. In this case, it is assumed that the reflected wave traveling in a direction other than the object to be measured 12 is dispersed to an extent that does not affect the propagation environment of the receiving point.

FIG. 6B shows an example of using a radio wave absorber 18 to absorb unwanted reflected waves and create a desired propagation environment. When generating a reflected wave of desired intensity toward the object to be measured 12, the RIS 16 shown in FIG. 6B generates a high-intensity reflected wave in the direction of path 38. Here, the reflected wave from path 38 is reflected by the RIS 16 and directed toward the radio wave absorber 18. The radio wave absorber 18 has the function of absorbing electromagnetic waves. Therefore, the high-intensity reflected wave heading toward path 38 does not affect the propagation environment at the position where the object to be measured 12 is placed. As a result, regardless of the generation of a reflected wave in the direction of path 38, the desired propagation space is reproduced inside the anechoic chamber 10.

[Hardware configuration of control server]
7 shows the hardware configuration of the control server 26. The control server 26 is configured as a general computer system, and includes a central processor (CPU) 40. Memories such as a ROM 44, a RAM 46, and a storage 48 are connected to the CPU 40 via a communication bus 42. A communication interface 50, an operation unit 52 and a display unit 54 serving as a user interface are further connected to the communication bus 42.

The control server 26 realizes the various functions described above by the CPU 40 executing the programs stored in the ROM 44. Specifically, the control server 26 realizes the simulation in step 100, the learning in step 104, the parameter derivation in step 108, the control of the RIS 16 and the channel emulator 24 in step 110, and the evaluation of the object to be measured 12 in step 112 by the CPU 40 proceeding with processing in accordance with the programs.

[Evaluation of the measured object]
Fig. 8 is a flow chart for explaining in detail the processing of steps 110 and 112 shown in Fig. 2. Here, first, the anechoic chamber 10 is set up (step 120). Specifically, the anechoic chamber 10 is set up with the shape, size, and material indicated by the parameters derived in step 108 above. In addition, the RIS 16, transmitting antenna 20, and receiving antenna (object of measurement 12) are set up in the anechoic chamber 10 according to the above parameters. If the parameters require the installation of a radio wave absorber 18, this is also installed.

Then, the control server 26 controls the RIS control device 22 and the channel emulator 24 as indicated by the above parameters (step 122).

As a result, a desired propagation environment that mimics the characteristics of real space is reproduced inside the anechoic chamber 10, particularly at the position of the measurement object 12 (step 124). In this step, it may be verified that the desired propagation environment is reproduced using a receiving antenna with known performance.

Once the desired propagation space has been recreated within the anechoic chamber 10, the control server 26 measures the communication quality, etc. of the measurement object 12 (step 126).

Then, the control server 26 is caused to perform an evaluation of the measured object 12 based on the measurement results (step 128).

[Modification of the first embodiment]
In the above example, the simulation in step 100, the learning in step 104, and the parameter derivation in step 108 are performed by the control server 26, but the present disclosure is not limited to this. These processes may be executed by another computer prepared separately from the control server 26.

In addition, in the above example, the control server 26 is configured to measure the communication quality and the like of the object 12 to be measured and evaluate the object 12 based on the results, but the present disclosure is not limited to this. These processes may be executed by other evaluation devices prepared separately from the control server 26.

Furthermore, in the above-mentioned embodiment 1, the propagation environment in real space is reproduced in the anechoic chamber 10. However, the present disclosure is not limited to this. The space in which the propagation environment is reproduced may be an outdoor space, or may be a normal indoor space that does not have a shielding function.

10 anechoic chamber 12 measurement object 16 RIS
18 Radio wave absorber 20 Transmitting antenna 22 RIS control device 24 Channel emulator 26 Control server 40 CPU
44 ROM

Claims

A Reconfigurable Intelligent Surface (RIS) is installed in a space that reproduces the electromagnetic wave propagation environment.
a RIS controller for providing control signals to the RIS;
A transmitting antenna installed in the propagation environment reproduction space;
a channel emulator for controlling the characteristics of the electromagnetic wave transmitted from the transmitting antenna;
a control server for controlling the RIS control device and the channel emulator;
The RIS is a propagation environment reproducing device that is a reflector having a characteristic of changing a reflection pattern in response to the control signal.
the propagation environment reproduction space is configured according to specifications indicated by parameters set to reproduce desired characteristics, which are propagation characteristics occurring at a measurement position in a real space;
The RIS and the transmitting antenna are arranged according to the specifications indicated by the parameters,
The control server includes:
controlling the RIS control device so that the RIS exhibits a reflection pattern indicated by the parameters;
2. The propagation environment reproducing device according to claim 1, further comprising: a process for controlling the channel emulator so that the transmitting antenna transmits electromagnetic waves with characteristics indicated by the parameters.
The propagation environment reproduction device according to claim 2, wherein the reflection pattern is a pattern that generates a reflection of a desired intensity in a direction toward a measurement position within the propagation environment reproduction space.
The propagation environment reproduction device according to claim 2, further comprising a radio wave absorber installed in the propagation environment reproduction space so as to absorb electromagnetic waves reflected by the RIS under the reflection pattern in a direction different from the direction toward the measurement position.
A propagation environment reproduction method for reproducing a desired propagation environment using a RIS installed in a propagation environment reproduction space for reproducing an electromagnetic wave propagation environment and a transmission antenna installed in the propagation environment reproduction space, comprising:
The RIS is a reflector having a characteristic of changing a reflection pattern in response to a control signal,
Calculating, by simulation, propagation characteristics generated in the propagation environment reproduction space under each parameter while changing parameters related to the propagation environment reproduction space, the RIS, and the transmitting antenna;
providing a propagation environment model with a combination of actual characteristics, which are propagation characteristics actually measured at a measurement position in a real space, and reproduction parameters, which are parameters calculated to generate propagation characteristics identical to the actual characteristics in the propagation environment reproduction space, as teacher data, to create a learning model that derives parameters to generate the propagation characteristics in the propagation environment reproduction space when a propagation characteristic to be reproduced is given;
providing desired propagation characteristics to the learning model to cause the learning model to derive parameters for generating the desired propagation characteristics;
constructing the propagation environment reproduction space according to the parameters derived by the learning model;
Arranging the RIS and the transmitting antenna in the propagation environment reproduction space according to the parameters derived by the learning model;
Controlling the RIS so that the RIS exhibits a reflex pattern represented by the parameters derived by the learning model;
Controlling a transmission signal from the transmitting antenna so that the transmitting antenna transmits electromagnetic waves with characteristics indicated by parameters derived by the learning model;
A method for reproducing a propagation environment including:
The propagation environment reproduction method according to claim 5, wherein the reflection pattern is a pattern that generates a reflection of a desired intensity in a direction toward a measurement position in the propagation environment reproduction space.
The method for reproducing a propagation environment according to claim 6, further comprising installing a radio wave absorber in the propagation environment reproduction space that absorbs electromagnetic waves reflected by the RIS in a direction different from the direction toward the measurement position under the reflection pattern.
The RIS was installed in a space that reproduced the electromagnetic wave propagation environment,
A transmitting antenna installed in the propagation environment reproduction space,
The RIS is a reflector having a characteristic of changing a reflection pattern in response to a control signal,
the propagation environment reproduction space is configured according to specifications indicated by parameters set to reproduce desired characteristics, which are propagation characteristics occurring at a measurement position in a real space;
The RIS and the transmitting antenna are arranged according to the specifications indicated by the parameters,
a function of controlling the RIS so that the RIS exhibits a reflection pattern indicated by the parameters;
a function of controlling a transmission signal from the transmitting antenna so that the transmitting antenna transmits electromagnetic waves with characteristics indicated by the parameters;
A propagation environment reproduction system configured to have the following.