WO2022050187A1

WO2022050187A1 - Wireless communication system

Info

Publication number: WO2022050187A1
Application number: PCT/JP2021/031538
Authority: WO
Inventors: 聡望月; 秀樹橋爪; 晴彦儘田
Original assignee: 日本板硝子株式会社
Priority date: 2020-09-01
Filing date: 2021-08-27
Publication date: 2022-03-10
Also published as: JP2023156537A

Abstract

Provided is a sustainable and robust network without degrading the characteristics of next-generation communications. This wireless communication system comprises: a UAV which functions as a relay station or a base station; a terminal which receives carrier waves via the UAV; and a window glass which includes an antenna for receiving power based on electromagnetic waves, receives power via the antenna, and wirelessly supplies, via the antenna, power to other electrically operating devices including the UAV.

Description

Wireless communication system

The present invention relates to a wireless communication system.

5G, which is currently operated as a wireless communication system, uses a high-frequency carrier wave of several GHz to several tens of G, and it is expected that a higher-frequency carrier wave will be used in the next-generation 6G and 7G wireless communication systems. Will be done. In addition, it is expected that the occupied bandwidth will be widened from several hundred MHz to several GHz.

In 5G communication systems and next-generation communication systems, while large-capacity communication and low delay characteristics can be obtained, there is a problem that the propagation distance of radio waves is significantly reduced as a physical phenomenon of radio wave propagation. It may be considered to increase the output of radio waves in order to deal with the decrease in propagation distance, but due to the influence of radio waves on the human body and restrictions such as the Radio Law and EMC standards of each country, it is not possible to increase the output of radio waves endlessly. Can not.

In order to make the next-generation communication system including 5G sustainable and robust from the conventional communication system, there are the following problems and problems.
(1) Since the carrier wave has a high frequency, the propagation distance is short due to the influence of physical propagation loss.
(2) Since the carrier wave has a high frequency, it is significantly affected by obstacles.
(3) In order to apply the communication network between terminals and base stations as constructed by 4G LTE to 5G, 6G, etc., an unrealistic number of base stations must be installed in the city.

In order to solve such a problem, a system has been proposed in which a relay station or a base station in a wireless communication system is configured by, for example, a UAV (Unmanned Aerial Vehicle) such as a drone (see, for example, Patent Document 1). By moving a drone that functions as a relay station or a base station, the problem of radio wave propagation distance can be solved.

When a large number of terminals are requesting low-delay communication from the UAV in a multi-connection state, if the UAV is about to run out of charge, there is a problem that it becomes difficult to secure the communication establishment state. As a possible example, it will be described below in this proposal.

Japanese Unexamined Patent Publication No. 2019-102872

In view of such problems, it is an object of the present invention to provide a sustainable and robust network without deteriorating characteristics such as propagation distance and communication time restrictions of next-generation communication.

In order to achieve the above object, the wireless communication system according to the present invention includes a UAV that functions as a relay station or a base station, a terminal that receives a carrier wave via the UAV, and an antenna that receives power based on electromagnetic waves. It is provided with a window glass that wirelessly feeds the power received by the antenna to other electrically operating devices including the UAV via the antenna.

According to the present invention, it is possible to provide a sustainable and robust network without deteriorating characteristics such as propagation distance and communication time restrictions of next-generation communication.

It is a schematic diagram explaining the problem of the wireless communication system based on the conventional 4G, 5G and the like. It is a schematic diagram explaining the problem of the wireless communication system based on the conventional 4G, 5G and the like. It is a schematic diagram explaining the basic structure of the wireless communication system which concerns on embodiment of this invention. It is a schematic diagram explaining the basic structure of the wireless communication system which concerns on embodiment of this invention. It is a schematic diagram explaining the flight range of UAV21. An example of the antenna units ANTs 1 to 12 constituting the array antennas A or B, which are arranged on the window glass of the building, will be described. It is a circuit diagram of an array antenna A or B (antenna unit: ANT1-12). An example of the configuration of the antenna unit arranged on one window glass will be described. An example of the configuration of the power storage circuit of the array antenna will be described. An example of a more detailed structure of the array antennas A and B is shown. It is a figure simulating a multi-band antenna pattern. An example of the band characteristic of the antenna circuit of FIG. 11 is shown.

Hereinafter, this embodiment will be described with reference to the attached drawings. In the attached drawings, functionally the same elements may be displayed with the same number. The accompanying drawings show embodiments and implementation examples in accordance with the principles of the present disclosure, but these are for the purpose of understanding the present disclosure and are never used for the limited interpretation of the present disclosure. is not it. The description of the present specification is merely a typical example, and does not limit the scope of claims or application examples of the present disclosure in any sense.

In this embodiment, the description is given in sufficient detail for those skilled in the art to implement the present disclosure, but other implementations and embodiments are also possible and do not deviate from the scope and spirit of the technical idea of the present disclosure. It is necessary to understand that it is possible to change the structure and structure and replace various elements. Therefore, the following description should not be construed as limited to this.

Before the description of the embodiment, the problems of the conventional wireless communication system based on 4G, 5G, etc. will be described with reference to FIGS. 1 and 2.

In a 5G wireless communication system, when wireless communication is used from a terminal located indoors (for example, a house 6), the radio wave may not be directly transmitted from the house 6 to the base station 1 due to the short propagation distance of the radio wave. obtain. In this case, for example, propagation paths 10 and 11 via a relay station installed on the roof of a neighboring building 3 can be secured, whereby communication between the house 6 and the base station 1 can be established. At this time, the antennas of the relay stations on the roofs of the house 6 and the building 3 can be considered to be in a fixed position and do not move, and the propagation path from the house 6 to the base station 1 is treated as being secured. Can be done.

On the other hand, mobile terminals such as smartphones and wearable devices, or wireless communication devices mounted on cars are carried by people (codes 4 and 5) or cars, and therefore, these devices and base station 1 are used. The propagation path between them changes over time. In that case, the relay stations installed on the rooftops of the

buildings

2 and 3 secure the

propagation paths

7, 8, 9, and 10, whereby the communication between those devices and the base station 1 is established. To. It should be noted that the above-mentioned communication is basically executed via the same route for both the uplink and the downlink.

When the mobile terminal or the like moves to an area that cannot be covered by the base station 1 as a result of moving by a person or a car, a hard / soft handover is performed, and an appropriate relay station for the new base station is provided in the same manner as described above. Select and communication is established. There are two ways to build a 5G system. One is a local 5G (Private 5G) that constitutes a 5G system in a closed area, and the other is WAN5G, which is often used for purposes other than corporate activities. WAN5G, which is used on a daily basis, has an overwhelmingly large number of terminals, network lines, users, applications, and market size compared to local 5G. The present invention is applicable not only to WAN 5G but also to local 5G, and is not limited by the application.

FIG. 2 is a diagram simulating the radio section from the UE (User Equipment) to the front of the gNB (base station) for a general 5G communication network regardless of whether it is a local 5G or a WAN 5G. For example, when a signal of a region 13 having a communication terminal or a network composed of a local 5G or a WAN 5G is transmitted to a base station 1, or data from a base station 1 is received in the region 13, a building is used. 12 may be present in the path connecting the base station 1 and the region 13. The signal transmitted from the region 13 propagates through the path 14, but is blocked by the building 12. Specifically, electric power cannot be propagated to the base station 1 which is a receiving point due to reflection, scattering, absorption and the like (reference numerals 15 and 16) which are physical phenomena of radio waves.

However, with the current 5G, it is possible to improve the quality of communication by using technologies such as beamforming and beam tracking. For example, as shown in FIG. 2, when communication cannot be performed on the transmission path 14, the array antenna 17 beamtracks to establish a propagation path 19 between the array antenna 17 installed on the roof of the building 12 and the region 13. And perform beamforming. Similarly, the array antenna 18 installed on the roof of the building 12 establishes a propagation path 20 between the array antenna 18 and the base station 1 by performing beam tracking and beamforming. By establishing the

propagation paths

19 and 20, communication between the base station 1 and the region 13 is established. That is, the data of the device in the area 13 can be transmitted by relaying the

array antennas

17 and 18 installed on the roof of the building 12 to the base station 1 located at a distance d.

In the communication path design in the conventional wireless communication system, the frequency to be used is fixed in a certain band, and the cell has a margin in consideration of the carrier frequency, the output level of the device, the spatial transmission loss, the transmission / reception antenna gain, and the like. We have been designing, that is, designing the layout of base stations. However, for 5G and next-generation wireless communication, a large-capacity line that bundles various other wireless protocols such as 4G band, 5G (Sub6 band (FR1)), 28GHz band (FR2), LPWA (920MHz band), etc. Will be transmitted to the backbone radio protocol with. It is important for software base stations that are functional / physically distributed, rather than fixed base stations and centralized to one station, to dynamically move hard devices. In the future, when the communication generation shifts to 6G and beyond, the center frequency of the carrier wave will surely increase, and the communication distance will be physically shortened. This shortening of the propagation distance has a trade-off relationship with the improvement of the communication speed.

In the existing wireless communication system used in 5G, the general concept of existing 5G wireless communication has been explained, but the frequency of the carrier wave used for future wireless communication will be higher and the bandwidth will be wider. Therefore, the communication distance and propagation loss L in the free space of radio waves under the same conditions of frequency, band, antenna gain, antenna height, transmission power, reception sensitivity, directivity, propagation environment, etc. are expressed by the following equation [Equation 1]. Can be expressed more generally.

[Number 1]
L = (4πd / λ) ²
However,
L: Free space propagation loss d: Communication distance λ: Wavelength

If the communication distance is doubled, the loss will be quadrupled, that is, the transmission power will be quadrupled. Considering the power ratio, it is 6 dB down. If the carrier frequency used for communication is doubled, the loss will be quadrupled. In addition to further shortening the communication distance, physical phenomena such as reflection, scattering, absorption, and interference cause adverse effects, and the stability of the network is significantly impaired. Since the optimum transmission / reception point always fluctuates with time due to multipath fading, the higher the frequency handled, the shorter the communication distance.

FIG. 3 is a schematic diagram illustrating a basic configuration of a wireless communication system according to an embodiment of the present invention, which is proposed in view of such a viewpoint. Since the same components as those in FIG. 2 are designated by the same reference numerals in FIG. 3, duplicated description will be omitted.

The wireless communication system of the present embodiment includes a drone or UAV21 that functions as a relay station. The UAV 21 has a function corresponding to the array antennas (repeaters) 17 and 18 of FIG. 2 and a base station function, and is configured to be able to fly in the air. The number of UAV21s is not limited to one as needed, and several tens of UAV21s may be arranged within a predetermined range, and the number of arrangements is not limited to a specific number.

The UAV 21 in FIG. 3 is a high-frequency carrier signal used for 5G or next-generation wireless communication with respect to a transmission signal to a region 13 having a terminal operating under local 5G or WAN 5G network conditions and a reception signal from the region 13, respectively. The contract is established through the propagation paths 23, 24, 25, and 26 using the above. At that time, in order to establish communication with UAV21, the terminal in the area 13 performs beam tracking and

beamforming

27 and 28 before communication, confirms the positions of the terminal and UAV21, and RSSI, S / N, Carrier Sense. Information related to communication quality such as Level and packet error rate (PER), communication path, delay time, etc. is shared. FIG. 3 is an example of a wireless network to be configured, and there is no limitation on the number of UAVs such as drones used as an actual configuration.

Similarly, in order to establish communication between UAV 21 and base station 1, beam tracking and beam forming 29 and 30 are performed before communication to confirm whether or not they can communicate with each other, and communication quality, communication path, and delay time are performed. Information related to the above is shared between the UAV 21 and the base station 1.

At this time, the position of the UAV 21 is not fixed as in the array antennas (repeaters) 17 and 18 in FIG. 2, and the UAV 21 automatically and dynamically selects the position and flies. As an example of the function possessed at that time, the UAV 21 shares information on the reception sensitivity of the radio wave with the terminal in the region 13 and / or the base station 1, so that the possibility of interruption of the propagation path and the error rate are minimized. In addition, the flight position is selected so that the reception intensity RSSI is maximized and the S / N ratio is maximized.

When a plurality of UAV21s are flying in the same area at the same time, the plurality of UAVs 21 grasp each other's positions based on GNSS information and avoid collisions, and from the terminals held by the UAV 21s. Considering information related to communication quality, communication route, delay time, etc., the optimization of each other's relative position is measured, and the optimization of the own machine position is automatically and dynamically determined.

The wireless communication system in which the UAV 21 functions as a communication relay station or a base station as shown in FIG. 3 has an advantage that it can also support ultra-high frequency wireless communication having a short radio wave propagation distance. On the other hand, the problem is how to secure the charge of the UAV 21 while minimizing the adverse effect on the communication delay specification of the wireless protocol used in the wireless network as much as possible.

Therefore, as shown in FIG. 4, the wireless communication system of this embodiment is arranged on the window glass of the

buildings

2 and 3, and receives and stores the electric power of various electromagnetic waves traveling in the air and stores the electric power. We propose array antennas A and B that radiate the generated power.

In FIG. 4, it is assumed that the UAV 21 has established a communication 38 with an area 13 having a terminal operating under local 5G or WAN 5G network conditions.
UAV21 is
・ Information from base station 1,
-Positional relationship information and transmission output information with the array antenna A or B-Output information transmitted from the UAV 21 to the array antenna A or B-RSSI (electrical strength) information received from the array antenna A or B-

Communication paths

36 and 37 From the PER (Packet Error Rate) information calculated from the communication data obtained by sending and receiving the test pilot signal used, the optimization of the position of the own aircraft is judged in real time and the flight is performed.

At this time, the flightable range of the UAV 21 is represented by the area S as a cross-sectional view along the vertical direction. The area S may be defined by the directions (30-32, 33-35) at which the array antennas A and B are capable of beam tracking and beamforming. The flight range can be recognized by the UAV 21.

In reality, as shown in FIG. 5, the flight range of UAV21 can be grasped as the volume of an elliptical cone in consideration of the radiation directivity of the array antennas A and B, and the volume V is given by the following equation. Be done. The

[Number 2]
V = 2/3 ・ r1 ・ r2 ・ d
V: Volume of flightable space r1: Horizontal plane Frenel radius r2: Vertical plane Frenel radius d: Height when made into an elliptical cone

The UAV21 determines its own communication quality environment, communication priority, and flightable range from the array antennas A and B that give control signals to the UAV21 and parameters such as RSSI, PER, and communication delay time of the UAV21. It is possible to recognize autonomously based on the information such as the pilot signal before the signal transmission. The UAV 21 can be controlled to satisfy various parameters regarding the flight range and ensure communication quality. There is no limit to the number of UAV21 aircraft that exist within the flight range (volume V).

However, since the UAV 21 has the role of a relay station or a base station, the communication quality with the higher-level base station 1 must be ensured. Therefore, the UAV 21 grasps the charge capacity of its own unit and calculates the communication quality with the base station 1. When the charge capacity is equal to or higher than the threshold value, the UAV 21 flies within the flightable range (volume V) and functions as a relay station or the like to ensure communication quality in the wireless communication system. On the other hand, when the charge capacity is below the threshold value, the UAV 21 can fly the same UAV 21'as the UAV 21 into the flightable range, transfer its own data to the UAV 21', and take over the role. Hereinafter, the same UAV21'that takes over may be referred to as a "copier".

The UAV21 can fly within the flightable range while sharing roles with the UAV21'which is a copier, and can receive wireless power supply from the array antenna A or B. Since the UAV 21 can receive wireless power supply from the array antennas A or B embedded in the window glass of the

buildings

2, 3 and the like, the charge capacity of the UAV 21 rarely falls below the threshold value, and the copy operation from the UAV 21 to the UAV 21'is performed. Can be reduced in the number of situations where.

In addition to the window glass of buildings (for construction), for example, by arranging similar array antennas on the shield glass (window glass) of automobiles and the glass of touch panels of mobile terminals such as smartphones, such The UAV 21 can also receive wireless power supply from the window glass. When a failure related to some hardware is detected in the UAV 21, information on the cause of the failure is transmitted via the base station 1 or the like, and the UAV 21 is ordered to return to the base station (not shown). At that time, the UAV 21 will let the UAV 21', which is a copier, take over the information and the role.

An example of the antenna units ANTs 1 to 12 constituting the array antennas A or B, which are arranged on the window glass of the building, will be described with reference to FIG. Each of the antenna units ANTs 1 to 12 is configured to receive electromagnetic waves from the outside, store the electromagnetic waves in a storage battery or the like, and wirelessly supply power to the UAV 21 by microwaves. The antenna configured on the window glass may be configured to have an array antenna configuration. Therefore, it can also have the functions of beamforming and beam tracking by a single window glass. The stored electric power is not limited to the electric power used in the UAV 21, but may be used for other purposes.

In many cases, the windowpanes of buildings are arranged in a grid pattern or other regularly. Taking advantage of the structural characteristics of the windowpanes on the wall surface of the regularly arranged building, the windowpanes having an array antenna or a single antenna are lined up as shown in FIGS. 6 and ANT1-12. Since the array antennas configured on each of these windowpanes are further arranged as shown in ANTs 1 to 12 as shown in FIG. 6, the array antennas should be used as a group of windowpanes arranged in an orderly manner on the wall surface of the building. Is possible. It is possible to supply the UAV 21 with the electric power used in the UAV 21 as a wireless power supply by microwaves, and also transmit a control signal necessary for the UAV 21 at an appropriate timing. Further, the UAV 21 can be wirelessly fed while performing beamforming and beam tracking appropriately.

The circuit diagram and operating principle of the array antennas A or B (antenna units ANT1 to 12) will be described with reference to FIG. 7. The array antennas A or B include, in addition to the antenna units ANT1 to 12, a CPU 40, a down-convert demodulation mixer 41, RF switches 42, 45, a preamplifier 43, a power amplifier 44, a power distributor 46, and a phase detector 47 to 52. It is composed of.

The CPU 40 controls the antenna units ANTs 1 to 12, specifically, generation of a baseband signal, demodulation of a received signal, estimation of an arrival direction of a radio wave based on phase calculation, determination of a transmission direction of a radio wave, and reception strength /. Calculation of PER / delay amount, calculation of attenuator adjustment amount for transmission / reception power, etc. are executed.

The RF switches 42 and 45 are connected to the power amplifier 44 side when emitting radio waves to the outside and transmitting electric power, and are connected to the preamplifier 43 side when receiving radio waves from the outside and receiving electric power. It works to be done. The carrier wave generated by the CPU 40 is sent to the power amplifier 44 via the down-convert demodulation mixer 41 and the RF switch 42, amplified, and then passed through the power distributor 46 and the phase detectors 47 to 52 to each antenna unit ANT1. It is supplied to ~ 12. An attenuator may be arranged in the circuit block of FIG. 7 for matching adjustment or output adjustment.

The preamplifier 43 and the power amplifier 44 are not limited to the positions shown in FIG. 7, and may be arranged on the antenna units ANT1 to 12 side of the power distributor 46 in a one-to-one correspondence with the individual antenna units ANT1 to 12. Further, an AD converter (ADC) may be mounted in the CPU 40, may be provided between the CPU 40 and the mixer 41, or an AD converter may be provided in each of the antenna units ANTs 1 to 12 on a one-to-one basis. May be good.

Further, the antenna units ANTs 1 to 12 may be arranged so as to support digital beamforming, analog beamforming, and hybrid beamforming in which analog / digital are mixed. Generally, a DA converter (Digital-Analog Converter) is arranged in front of the power amplifier 44, and an AD converter (Analog-Digital Converter) is arranged in front of the preamplifier 43.

The circuit block of FIG. 7 is a configuration example of a hardware circuit related to beamforming and beamforming, and a configuration example of a circuit that realizes beamtracking and beamforming is not limited to FIG. Further, the basic principles regarding beamforming and beam tracking in both of the array antennas configured as a single windowpane and the windowpanes group having the array antenna shown in FIG. 7 will be described below.
When the arrangement interval of the antenna units ANT1 to 12 is W (see FIG. 6) and the phase difference between the antenna units ANT1 to 12 is φ1 to φ12, the phase difference Δφ when power is received by each of the antenna units ANT1 to 12 Can be given by the following equation.

[Number 3]
Δφ = (2π / λ) ・ W ・ sinθ

In the circuit illustrated in FIG. 7, when the time delay amount of the signal received by each antenna unit ANT1 to 12 is represented by the phase difference φ1 to φ12 of the signal, the arrival direction of the radio wave is determined based on the phase difference φ1 to 12. be able to. Further, a confirmation response signal for transmitting the reception of the radio wave to the transmission destination UAV 21 may be transmitted from the array antenna A or B. Similarly, when the transmission destination is ANT1 to 12, the confirmation response signal is transmitted from the UAV21.

Further, the radiation direction of the radio wave transmitted at the next timing is determined based on the phase difference φ1 to 12 calculated at the time of receiving the radio wave and in consideration of RSSI (electric field strength), PER, etc. received at the same time at the time of reception. At this time, the gain amount of the power amplifier 44 or the attenuation amount of the programmable attenuator (attenuator) is also adjusted, and the radio wave indicated by the arrow 53 in FIG. 7 is adjusted together with the radiation angle θ determined from the phase shift amount. The radial direction is controlled.

How much antenna gain is given in which radiation direction when the phase difference φ1 to 12 of each antenna unit ANT1 to 12 is set is analyzed in advance at the time of array antenna design. According to this preliminary analysis result, the CPU 40 performs beamforming by giving phase differences φ1 to φ12 to each antenna unit ANT1 to ANT1 to 12 when transmitting radio waves, and also performs beamforming when receiving radio waves. Beamtracking is executed by detecting the phase difference φ1 to φ12 of the received signal in 12. By providing a power detector (not shown), the correction amount for correcting the mismatch regarding the amplitude or phase generated by the adjustment of the power amplifier 44 at the time of transmitting the radio wave and the adjustment of the preamplifier 43 at the time of receiving the radio wave is also provided. , It is possible to realize maximum power transmission in a form in which phase matching is obtained.

The antenna units ANTs 1 to 12 have a function of receiving electric power from innumerable radio waves propagating in space and storing the received electric power in a storage battery. The stored electric power is wirelessly supplied to the UAV 21 by electromagnetic waves transmitted via the antenna units ANTs 1 to 12, whereby the UAV 21 is charged. Currently, radio waves used in various wireless protocols are crowded and flying in space. Radio waves cannot be visually observed, and it is difficult to grasp the status of innumerable radio waves in real time. Such radio waves cause an interference phenomenon due to interference, which causes deterioration of communication quality. By recovering the electric power from such innumerable radio waves, it can be used as a power source for charging the UAV 21 as described above, and can also contribute to the improvement of communication quality.

Even in the next-generation wireless communication network including 5G, where beamforming is the basic technology, the radio waves generated during antenna radiation include radiation other than the main lobe such as side lobes and back lobes, which depend on the antenna system design. Also, the radio waves radiated by the antenna include radiated power in directions that the antenna does not need / does not need, which has characteristics such as omnidirectionality in the horizontal plane. In the present invention, such unnecessary radio waves can be collected in the vicinity of the transmitting antenna and used as electric power for charging the UAV 21.

Many of the antennas currently in use radiate a lot of power in a useless direction different from the direction in which radio waves should be radiated. According to the present embodiment, the array antenna arranged on the window glass or the like recovers these useless electric powers in the vicinity of the transmitting antenna or in the distant field region, and stores the electric powers for another work amount. It can be converted and reused.

With reference to FIG. 8, a configuration example of an antenna unit arranged on one window glass will be described. The antenna unit is arranged in a module 64 provided in the window sash 60, and the antenna element 62 may be arranged on the window glass 61. In the example of FIG. 8, the antenna elements 62 are arranged in a grid pattern in 4 rows and 4 columns, but the present invention is not limited to this, and it is sufficient if the antenna elements 62 are arranged with a certain regularity. Is not limited to the illustrated example. The antenna arranged instead of the entire surface of the window as shown in FIG. 8 may be provided for a part of the area with respect to the window.

Further, it is not necessary to arrange a plurality of antenna elements 62 in one window, one antenna element 62 is formed in one window, and the array antenna A or the array antenna A or by the plurality of antenna elements 62 arranged in the entire building. B may be formed. The plurality of antenna elements 62 have the RF module and the power storage circuit shown in FIG. 9 in the RF line 63 and the conductive window sash 60. The antenna element 62 is a rectangular conductive layer in the example shown in FIG. 8, but is not limited thereto. The type of antenna element is not limited to the pattern antenna, and general sleeve antennas, Yagi antennas, waveguides, horn antennas, leaky coaxial cables, dipole antennas, flat opening antennas, etc. can also be adopted. Further, the antenna may be directional or omnidirectional.

An example of the configuration of the power storage circuit of the array antenna will be described with reference to FIG. This power storage circuit includes a rectifier circuit 65 connected to the antenna unit ANT and a power storage circuit 66. The rectifier circuit 65 is a full-wave rectifier circuit in the example of FIG. 9, but is not limited thereto. The high frequency power (waveform) received by the antenna unit ANT is rectified via the rectifier circuit 65 composed of the inductance and the capacitance, and is stored in the power storage circuit 66. As an example, the power storage circuit 66 can be mounted as a module 64 on a window sash 60 or the like. The circuit configuration of the power storage circuit 66 is not limited to a specific one.

Further, the array antenna A or B is not limited to the one that receives the radio wave of the radio protocol using the radio wave of a specific frequency, and the frequency of the received radio wave does not matter as long as it can be used for storage. The type of wireless protocol is also not limited to a specific one. Further, there are no restrictions on the wireless power feeding method of the array antennas A or B, the structure of the software, and the operation.

The pattern antenna to be realized may be a multi-band system or a single-band system, and whether it is a single band or a multi-band can be selected according to the antenna design. Further, the antenna may have a structure capable of giving a varicap diode or a physical reactance component change, and may be configured to be able to dynamically change the frequency characteristics. Further, as a mounting technique for adjusting the frequency characteristics, a left-handed circuit using CRLH or a metamaterial may be mounted to realize real-time performance.

With reference to FIG. 10, an example of a more detailed structure of the array antennas A and B is shown. The array antenna A or B includes a transparent conductor 71 formed in the window 70. The transparent conductors 71 are neatly arranged in the window 70 and function as an antenna. Each antenna element 71 is composed of, for example, a cross-shaped conductor portion and a conductor orthogonal to the tip of the cross-shaped portion, but this is an example and is not limited to this shape.

Each antenna element 71 includes through conductors (VIA) 73 to 78 at the intersection 72 of the cross conductor portions. In the example of FIG. 10, the MIMO array antennas arranged in a grid pattern in 3 rows × 3 columns are illustrated, but the number of antennas in the vertical and horizontal directions of the grid is not limited to a specific number. The VIA 73 to 78, which are feeding points provided in each antenna element 71, use a medium 70 as a window as a substrate, and high-frequency signals are transmitted and received at these feeding points. FIG. 11 is a diagram simulating a multi-band antenna pattern. FIG. 12 shows an example of the frequency characteristics of the antenna circuit of FIG.

The frequency characteristics of the antenna of this embodiment are not limited to those having one pass band. As shown in FIG. 12, it may have two or more pass bands centered on frequencies f1 and f2. Further, the antenna may have a function of mounting a structure using a liquid crystal display or a metamaterial structure and dynamically adjusting the optimum frequency characteristics.

[effect]
As described above, according to the system of the present embodiment, the following effects can be obtained.
(1) The end-to-end communication distance can be secured in a wider area than in the past.
(Explanation) Since a UAV capable of flying in the air is used as a base station or a relay station to form a wireless communication network, a propagation path is formed three-dimensionally, unlike a conventional system that is a communication network that is almost horizontal to the ground. can do. Therefore, it is possible to avoid obstacles and form a propagation path, and it becomes easy to secure a propagation distance in a wider area than in the conventional case.

(2) It is possible to improve the reliability of the entire communication network using wireless signals.
(Explanation) Since the UAV can be a relay station or a base station, obstacles can be avoided and a propagation path can be formed, so that the occurrence of multipath can be suppressed and communication quality deterioration due to fading can be suppressed. It can be suppressed. In addition, by using the UAV as a relay station or base station, unlike the relay station or base station that is conventionally fixed to the ground object, the position of the UAV that is the relay station or base station can be determined in real time depending on the communication state. , It becomes possible to optimize spatially. Then, the frequency with which the UAV returns to the base station is determined by wirelessly supplying power to the UAV functioning as such a relay station or base station from an array antenna installed on the window glass of a building or an automobile. It can be significantly reduced and the continuous flight time will be longer. If the flight time is long, one UAV can continuously function as a base station and a relay station, and communication efficiency is improved. There will be a considerable amount of delay when performing the takeover function with the alternative device at the time of replacement, but since the frequency of replacement can be reduced as much as possible, it will occur in the wireless network of the own device. The delay frequency can be suppressed as much as possible.

(3) It is physically possible to select the priority of the information to be communicated.
(Explanation) In a conventional wireless communication system, selection of priority of transmitted / received wireless signals is included in a pilot signal transmitted / received before transmission / reception of a wireless signal or a signal header related to information, as is used in 5G. It is executed according to the status information. In the event of an emergency / emergency, the UAV's flight path is automatically determined with the highest priority to ensure the radio signal quality with any specified information, in addition to the conventional electrical priority selection. It can be physically selected and flown.

(4) By collecting and storing radio waves that are not related to the main communication existing in the space (energy harvesting), it leads to cutting off unnecessary multipath paths on the propagation path and coexisting with other systems. It will be more effective.
(Explanation) Under conditions such as interference with other systems and cell-to-cell interference between adjacent cells using the same frequency, recovering the power of unnecessary radio waves does not give interference waves to other systems, and other systems. It will not receive the interference wave from the above, which will lead to the suppression of the generation of unnecessary multipath at the receiving point.
However, in the communication method that positively uses the communication path from the multipath, the collection function can be stopped (OFF) by software.

(5) It is possible to perform more efficient wireless power supply as compared with the conventional technology.
(Explanation) Using a MIMO array antenna, information on the position of a UAV to be fed can be acquired by GNSS, beam tracking by a MIMO array antenna, or the like, and wireless power can be supplied to the UAV by beamforming technology. When the MIMO array antenna is embedded in the window of a building, the obstacles between the MIMO array antenna and the UAV can be reduced, so that power can be supplied while suppressing interference from other systems. Further, since the loss between communication paths can be suppressed, it is possible to realize highly efficient wireless power supply.

[Modification example]
The various configurations shown in the above-described embodiments can be added, replaced, modified, deleted, and the like within a range obvious from well-known techniques and conventional means. Further, the communication system is not limited to 5G and 6G, and can be applied to Wi-Fi, LPWA, and all other radio protocols (modulated signal, unmodulated signal, and type of modulated signal). Further, the present invention is not limited to the radio communication frequency including AM / FM wave, millimeter wave, optical communication and the like, and the signal frequency band.

The present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the described configurations. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. .. Further, it is possible to add / delete / replace other known configurations with respect to a part of the configurations of each embodiment.

1 ... base station, 2, 3 ... building, 6 ... house, 7, 8, 9, 10 ... propagation path, 12 ... building, 13 ... area, 14 ... transmission path, 17, 18 ... array antenna (repeater)
19-26 ... Propagation path, 40 ... CPU, 41 ... Mixer, 42 ... RF switch, 43 ... Preamplifier, 44 ... Power amplifier, 45 ... RF switch, 46 ... Power distributor, 47-52 ... Phaser, 61 ... Window Glass, 62 ... antenna element, 63 ... RF line, 64 ... window sash, 65 ... rectifying circuit, 66 ... power storage circuit, 70 ... window, 71 ... transparent conductor, 72 ... intersection, 73-78 ... through conductor (VIA) , A, B ... Array antenna, ANT1-12 ... Antenna unit.

Claims

UAVs that function as relay stations or base stations,
A terminal that receives a carrier wave via the UAV,
A wireless device including an antenna that receives electric power based on electromagnetic waves, and a window glass that wirelessly supplies electric power received and stored by the antenna to other electrically operating devices including the UAV via the antenna. Communications system.
The wireless communication system according to claim 1, wherein the window glass is a glass for a mobile terminal such as a window glass for construction, a window glass for automobiles, and a smartphone.
The wireless communication system according to claim 1, wherein the window glass includes a device configured to supply electric power stored toward the UAV.
The wireless communication system according to claim 1, wherein the window glass includes a device configured to confirm the position of the UAV by beam tracking and emit an electromagnetic wave toward the UAV by beamforming.
The wireless communication system according to claim 1, wherein the antenna includes a plurality of antenna units arranged on a plurality of windowpanes of a building.
The UAV autonomously determines its own communication quality environment and communication priority based on various parameters including RSSI, PER, and communication delay information (Communication Latency), and satisfies the above various parameters regarding the flight range. The wireless communication system according to claim 1, which has a function of ensuring communication quality.
A second UAV different from the UAV is further provided, and when the UAV returns to the base station for charging, the second UAV functions as a copier that inherits the information of the UAV. The wireless communication system described in.
The wireless communication system according to claim 1, which uses a UAV having a function of significantly reducing the frequency of return for charging rather than wireless power supply.