WO2020124490A1

WO2020124490A1 - Multiple-input multiple-output antenna, base station and communication system

Info

Publication number: WO2020124490A1
Application number: PCT/CN2018/122376
Authority: WO
Inventors: 唐先锋; 张鲁奇; 刘余; 李昆
Original assignee: 华为技术有限公司
Priority date: 2018-12-20
Filing date: 2018-12-20
Publication date: 2020-06-25
Also published as: CN113169446B; CN113169446A

Abstract

The present application provides a multiple-input multiple-output antenna, a base station comprising the multiple-input multiple-output antenna, and a communication system comprising the base station. The multiple-input multiple-output antenna comprises a plurality of antenna units; a dielectric plate is provided in each antenna unit, and the dielectric plate is made from a material having a near zero refractive index, so that a phase difference between any two of the electromagnetic wave beams, emitted to the dielectric plate and transmitted by different channels, becomes larger after being refracted by the dielectric plate as compared to that before being refracted. In the present application, electromagnetic wave beams need to pass through the dielectric plates and then are transmitted to the feed source, so that before being received by the feed source, the electromagnetic wave beams transmitted by different channels pass through the dielectric plates for phase difference amplification, and therefore the phase difference between the electromagnetic wave beams transmitted by different channels and emitted from the dielectric plates is increased, thus reducing the correlation between electromagnetic beams transmitted by different channels, so that the antenna units are able to perform super-resolution on the electromagnetic wave beams transmitted by different channels.

Description

Multi-input multi-output antenna, base station and communication system

Technical field

The present application relates to the technical field of antennas, and in particular, to a multiple input multiple output antenna, a base station including the multiple input multiple output antenna, and a communication system including the base station.

Background technique

Microwave backhaul has the characteristics of rapid deployment and flexible installation, and is one of the main solutions for mobile backhaul. With the development of mobile broadband and fixed broadband networks, microwave backhaul in conventional frequency bands faces the following challenges: With the massive deployment of 4G networks and the evolution to 5G, bandwidth requirements continue to increase, and macro stations require Gbps-level bandwidth; increased bandwidth requires consumption With more frequency resources, the spectrum resources of the conventional frequency band (6-42GHz) are becoming increasingly tense, and it is very difficult to obtain frequency points to meet the demand.

Multiple-Input Multiple-Output (MIMO) antennas are important solutions for large-capacity, long-distance microwave backhaul, and can effectively increase channel capacity. However, in the practical application of MIMO antennas, the antenna array is generally required to be deployed in a small range to reduce the volume of the antenna, so that the spacing between adjacent antennas is much smaller than the Rayleigh distance, thereby allowing different channels to be transmitted The phase difference of the beam is too small, making the beam correlation of different channel transmissions too strong, making the MIMO antenna system degenerate into a single-input single-output (Single-Input Single-Output, SISO) system.

Summary of the invention

The present application provides a multiple input multiple output antenna, a base station applying the multiple input multiple output antenna, and a communication system, aiming to increase the phase difference between electromagnetic beams transmitted through different channels and reduce the electromagnetic beams transmitted through different channels The correlation between them realizes the super-resolution of electromagnetic beams transmitted by different channels.

In a first aspect, the present application provides a multiple input multiple output antenna for receiving electromagnetic beams transmitted from two or more channels. The multiple input multiple output antenna includes multiple Antenna units, each of which includes a radome, a feed, optical components, and a dielectric board. The radome has a front end, and the electromagnetic beam is transmitted into the radome through the front end. The feed source is provided in the radome for receiving the electromagnetic beam passing through the front end. The optical component is provided in the radome for converging the electromagnetic beam passing through the front end to the feed source through refraction or reflection, and the optical component includes an optical axis. The dielectric plate is disposed in the radome, the dielectric plate is disposed perpendicular to the optical axis; the electromagnetic beam is transmitted to the feed through the dielectric plate; the dielectric plate is a material with near zero refractive index Formed, the near-zero refractive material is a material with an absolute value of refractive index greater than 0 and less than 1; any two electromagnetic beams transmitted into the dielectric plate transmitted through different channels are refracted by the dielectric plate relative to The phase difference before refraction becomes larger.

In the present application, a dielectric plate formed by setting a near-zero refractive index material with an absolute value of refractive index greater than 0 and less than 1 in the antenna unit. Since the electromagnetic beams transmitted through different channels have an angle between them, that is, the incident angles of the electromagnetic beams transmitted to the dielectric plate through different channels are different. Since the dielectric plate in the present application is formed of near zero-refractive index material, the difference in the transmission distance of electromagnetic beams transmitted through different channels when passing through the dielectric plate is larger than the difference in transmission in air Much more, so that the phase difference of the electromagnetic beams transmitted by different channels will become larger after they are emitted than before they enter the dielectric plate, that is, the electromagnetic beams transmitted by different channels can be amplified by the dielectric plate to achieve two beams The phase difference, thereby reducing the correlation of beams transmitted by different channels, realizes super-resolution of beams transmitted by different channels.

In some embodiments of the present application, the absolute value of the refractive index of the dielectric plate is greater than 0 and less than 0.1. In these embodiments, the refractive index of the dielectric plate is close to zero, so that the phase difference of electromagnetic beams transmitted from different channels can be increased as much as possible to obtain a better beam resolution effect.

In some embodiments of the present application, the dielectric plate includes an incident surface and an exit surface that are opposite to each other, and a side surface connected between the incident surface and the exit surface. The side surface is covered with a reflective layer. The reflecting layer is used to reflect the electromagnetic beam directed to the side surface to the exit surface, and make the reflected electromagnetic beam produce a phase of 180°+Nⅹ360° compared to the electromagnetic beam before reflection Variation, where N is a natural number.

By providing the reflective layer, the electromagnetic beam irradiated on the side surface can be reflected to the exit surface to exit, thereby avoiding leakage caused by the electromagnetic beam exiting from the side surface and avoiding loss of the electromagnetic beam signal. And, from the perspective of the correlation between the electromagnetic beams, the phase difference between different electromagnetic beams is 0 degrees and 180 degrees, and the correlation is the same. Therefore, in this application, the electromagnetic beam generates a phase change of 180°+Nⅹ360° through the reflective layer, which can ensure that the beam reflected by the reflective layer and the beam not reflected by the reflective layer have phase consistency, that is, Avoid changing the correlation between the electromagnetic beam reflected by the reflective layer and the electromagnetic beam not reflected by the reflective layer.

Wherein, the reflection layer is a metal reflection layer formed of a metal material, so that the electromagnetic beam reflected by the reflection layer produces a 180° phase change.

In some embodiments of the present application, the thickness h of the dielectric plate in a direction perpendicular to the incident surface satisfies the formula

Where Δφ refers to the change value of the phase difference of the first and second electromagnetic beams transmitted by different channels after being refracted by the dielectric plate compared to the phase difference before refraction; c is the speed of light and n is The refractive index of the dielectric plate, θ ₁ is the difference between the incident angle of the first electromagnetic beam and the incident angle of the second electromagnetic beam, and ω is the circular frequency of the incident electromagnetic beam.

In this application, the thickness of the dielectric plate satisfies the formula

In the case where the material of the dielectric plate and the direction in which the electromagnetic beams of different channels enter the dielectric plate are fixed, the thickness of the dielectric plate can be set according to the phase difference of the electromagnetic beams transmitted by the different channels finally required to obtain The phase difference of the electromagnetic beams required for transmission on different channels.

In some embodiments of the present application, the phase difference between the two electromagnetic beams transmitted through different channels after being refracted by the dielectric plate is 90°. By controlling the thickness of the dielectric plate or adjusting the material of the dielectric plate (that is, adjusting the refractive index of the dielectric plate), the phase difference between the two electromagnetic beams transmitted through different channels can be 90°, When the phase difference between the two electromagnetic beams is 90°, the correlation between the two electromagnetic beams is the smallest.

In some embodiments of the present application, the optical component includes a main reflector, the feed and the dielectric plate are sequentially located between the main reflector and the front end of the radome, the main reflector has a main A reflection surface, the dielectric plate faces the main reflection surface, and the main reflection surface is used to reflect the electromagnetic beam incident through the dielectric plate; the dielectric plate is on a reference plane perpendicular to the optical axis The orthographic projection covers the orthographic projection of the reflective surface on the reference surface. In these embodiments, since the orthographic projection of the dielectric plate on the reference surface covers the orthographic projection of the reflective surface on the reference surface, all electromagnetic beams incident on the main reflective surface can pass first The dielectric plate can be transmitted to the main reflection surface only after the phase difference is amplified, so that the antenna unit can better resolve all incident electromagnetic beams.

In some embodiments, the optical component further includes a sub-reflector located between the dielectric plate and the feed, and the sub-reflector includes a sub-reflective surface facing the feed. The secondary reflection surface is used to reflect the electromagnetic beam reflected by the main reflection surface to the feed source. By providing the sub-reflector, the feed source can be provided between the main reflector and the sub-reflector, and the size of the antenna along the optical axis of the optical component can be reduced. For example, when there is no secondary reflector, the feed is located at the convergence point of the electromagnetic beam in front of the main reflection; and when the secondary reflector is provided, the secondary reflector is placed on the path where the electromagnetic beam converges The electromagnetic beam is reflected on the secondary reflection surface of the secondary reflector and reflected into the feed, at this time, the size of the antenna unit in the direction of the optical axis of the optical component may be only The distance between the main reflector and the sub-reflector makes it possible to reduce the size of the antenna unit in the optical axis direction of the optical component.

In some other embodiments of the present application, the optical component includes a lens, and the lens and the dielectric plate are sequentially located between the feed and the front end of the radome, and the lens is used to pass the medium The electromagnetic beam of the plate is refracted to the feed; the orthographic projection of the dielectric plate on the reference plane covers the orthographic projection of the lens on the reference plane. In these embodiments, the lens converges the incident electromagnetic beam, so that the feed source can receive as many electromagnetic beams transmitted by different channels as possible. Similarly, by setting the orthographic projection of the dielectric plate on the reference plane perpendicular to the optical axis to cover the orthographic projection of the lens on the reference plane, the electromagnetic beams that enter the lens and converge to the feed can be first After passing through the dielectric plate, the phase difference between the electromagnetic beams transmitted by the different channels is amplified and then received by the feed source, so that the antenna unit can easily distinguish the electromagnetic beams transmitted by the different channels.

In some embodiments of the present application, the optical component includes a main reflector, a diverging lens, and a converging lens; the diverging lens is disposed coaxially with the converging lens, and the dielectric plate is located between the diverging lens and the converging lens Between, the divergent lens is used to convert the electromagnetic beam directed to the dielectric plate into a parallel electromagnetic beam, and the convergent lens is used to convert the electromagnetic beam directed from the feed to the dielectric plate into a parallel Electromagnetic beam; the feed is located on the side of the converging lens away from the dielectric plate, the main reflector has a main reflecting surface, the dielectric plate, the feed, the divergent lens and the converging lens and the main reflection The main reflection surface is used to reflect the incident electromagnetic beam to the dielectric plate.

Through the divergent lens and the converging lens, the electromagnetic beam condensed by the main reflector is converted into a parallel beam and then incident into the dielectric plate, so that the dielectric plate can realize the phase difference of the electromagnetic beams of different channels At the same time, the size of the dielectric board can be reduced, the cost can be saved, and the volume of the antenna unit can be reduced.

In some embodiments of the present application, the focal lengths of the converging lens and the diverging lens are the same, so that the electromagnetic beam entering the feed through the converging lens and the diverging lens is relative to the front of the converging lens and the diverging lens The angle of the electromagnetic beam does not change.

In some embodiments of the present application, the divergent lens, the dielectric plate, and the condensing lens are sequentially disposed between the main reflector and the feed, so that the electromagnetic beam passes through the main reflector first The reflecting surface reflects to the divergent lens, and after passing through the diverging lens, the electromagnetic beam converged after being reflected by the main reflecting surface is converted into a parallel beam, and then transmitted to the dielectric plate; the dielectric plate transmits different channels The phase difference between the electromagnetic beams is amplified and transmitted to the converging lens, and the converging lens converges the parallel electromagnetic beams exiting through the dielectric plate to the feed, and finally the feed receives a large phase difference Electromagnetic beams transmitted by different channels.

In some embodiments of the present application, the reflective surface antenna further includes a secondary reflector, the divergent lens, the dielectric plate, the condensing lens, and the feed are sequentially located on the secondary reflector and the primary reflector In between, the sub-reflector includes a sub-reflection surface toward the feed, and the sub-reflection surface is used to reflect the electromagnetic beam reflected by the main reflection surface to the dielectric plate. In these embodiments, the electromagnetic beam reflected by the main reflection surface of the main reflector needs to be reflected by the sub-reflection surface of the sub-reflector before entering the divergent lens, the dielectric plate, and the convergence The lens and the feed. That is, the sub-reflector is located on the transmission path where the electromagnetic beam is transmitted from the main reflector to the feed, therefore, compared with the antenna unit without the sub-reflector, the provision of the sub-reflector can be reduced The size of the antenna unit along the optical axis of the optical component reduces the volume of the antenna unit.

Wherein, the diameters of the divergent lens, the converging lens and the diameter of the dielectric plate are smaller than the diameter of the secondary reflector, in order to minimize the diameters of the diverging lens, the converging lens and the dielectric plate For the occlusion of the electromagnetic beam.

In some embodiments of the present application, the optical components include a refractive lens, a diverging lens, and a condensing lens, and the refractive lens, the diverging lens, the dielectric plate, and the converging lens are sequentially disposed on the radome along the optical axis Between the front end of the antenna and the feed; the refractive lens is used to converge the electromagnetic beam passing through the front end of the radome, and the divergent lens is used to convert the electromagnetic beam converged by the refractive lens into parallel electromagnetic waves The beam is incident on the dielectric plate, and the converging lens is used to converge the electromagnetic beam passing through the dielectric plate to the feed source.

In these embodiments, the refractive lens converges the incident electromagnetic beams, so that the feed source can receive as many electromagnetic beams transmitted by different channels as possible. In addition, the divergent lens and the convergent lens convert the electromagnetic beam converged by the main reflector into a parallel beam and then enter the dielectric plate, so that the phase of the electromagnetic plate on the electromagnetic beams of different channels can be realized When the difference is changed, the size of the dielectric board can be reduced, the cost can be saved, and the volume of the antenna unit can be reduced.

In a second aspect, the present application also provides a base station, including the multiple-input multiple-output antenna in the foregoing various embodiments. Since the multiple-input multiple-output antenna can distinguish the electromagnetic beams transmitted by different channels, the base station has a better signal transmission effect.

In a third aspect, the present application also provides a communication system, the communication system includes at least two of the above base stations, and two adjacent base stations perform communication. Since the multiple-input multiple-output antennas of the base station can distinguish the electromagnetic beams transmitted by different channels at a high level, a signal transmission effect between two adjacent base stations can be improved.

BRIEF DESCRIPTION

FIG. 1 is a schematic diagram of a communication architecture of a multiple input multiple output antenna provided by an embodiment of the present application;

2 is a schematic structural diagram of a multi-input multi-output antenna provided by an embodiment of the present application;

3 is a schematic diagram of a phase difference amplification model of an electromagnetic beam transmitted through different channels by a dielectric board according to an embodiment of the present application;

4 is a schematic structural diagram of another multiple input multiple output antenna provided by an embodiment of the present application;

5 is a schematic structural diagram of another multiple input multiple output antenna provided by an embodiment of the present application;

6a is a schematic structural diagram of another multiple input multiple output antenna provided by an embodiment of the present application;

FIG. 6b is an enlarged schematic diagram of position II in the multiple input multiple output antenna provided by the embodiment of FIG. 6a;

7 is a schematic structural diagram of another multiple input multiple output antenna provided by an embodiment of the present application;

8 is a schematic structural diagram of another multiple input multiple output antenna provided by an embodiment of the present application;

9 is a schematic structural diagram of a base station according to an embodiment of the present application.

detailed description

The technical solutions in the embodiments of the present application will be described clearly and completely with reference to the drawings in the embodiments of the present application. Among them, the drawings are for illustrative purposes only, and only schematic diagrams are shown, which cannot be understood as limitations to the patent.

The present application provides a multiple-input multiple-output (MIMO) antenna. The MIMO antenna includes multiple antenna units, so that when two groups of MIMO antennas communicate, signals can pass through multiple antennas of the MIMO antenna simultaneously. The unit performs antenna transmission and reception, thereby improving communication quality. And can make full use of space resources, achieve multiple transmission and multiple reception through multiple antenna units, without increasing the spectrum resources and antenna transmission power, the system channel capacity can be doubled. That is, each group of the MIMO antennas can receive electromagnetic beams transmitted from two or more channels, or send electromagnetic beams through two or more channels. For example, in the embodiment shown in FIG. 1, the MIMO antenna A includes an antenna unit A1 and an antenna unit A2; the MIMO antenna B includes an antenna unit B1 and an antenna unit B2. Among them, each antenna unit in the MIMO antenna can be used as a signal receiving antenna or a signal transmitting antenna. In FIG. 1, MIMO antenna A is used as a signal transmitting antenna, and MIMO antenna B is used as a signal receiving antenna. The electromagnetic beam emitted by antenna unit A1 is transmitted through channel h11 and channel h12 to antenna unit B1 and antenna unit B2, respectively. The electromagnetic beam mirror channel h12 and channel h22 transmitted by A2 are transmitted, that is, when the MIMO antenna A transmits the channel to the MIMO antenna B, it can be transmitted through multiple channels, which increases the channel transmission capacity. In addition, the directions of electromagnetic beams transmitted to different channels through the same antenna unit are different, and the directions of electromagnetic beams transmitted to the same antenna unit through different channels are also different.

Referring to FIG. 2, this application provides a MIMO antenna. The MIMO antenna includes multiple antenna units 100, and the multiple antenna units 100 are arranged in an array. It can be understood that, in other embodiments of the present application, the multiple antenna units 100 may also be arranged in other ways, for example, they may be arranged in a chaotic manner, or may be arranged according to a certain rule.

Each antenna unit 100 includes a feed 10, a dielectric board 20, a radome 30, and an optical component 40. The feed source 10, the dielectric board 20 and the optical component 40 are all contained in the radome 30.

The radome 30 has a front end 31, and the front end 31 is transmitted into the radome 30 through electromagnetic beams transmitted through different channels. The radome 30 may be made of polycarbonate (PC), polyethylene (PE), or other materials, to protect the internal structure of the antenna from the influence and interference of the space environment, and at the same time improve the operational reliability of the antenna.

The feed 10 can transmit or receive electromagnetic beams. Wherein, the transmission path of the electromagnetic beam received by the feed source 10 is the same as the transmission path of the electromagnetic beam sent by the feed source 10. The following mainly describes the electromagnetic beam reception by the feed source 10 for unilateral description.

The optical component 40 is used to refract or reflect the electromagnetic beam passing through the front end of the radome 30, and the electromagnetic beam refracted or reflected by the optical component 40 is received by the feed source 10. Here, the optical component 40 has an optical axis 41 at a substantially center. The optical axis 41 is an imaginary line in the optical component 40, and the electromagnetic beam rotates around the rotation axis 41 without any change in optical characteristics.

The dielectric board 20 is provided in the radome 30. The dielectric plate 20 has a plate shape and is disposed perpendicular to the optical axis 41. Wherein, the dielectric plate 20 and the optical axis 41 arranged perpendicularly in this application may mean that the dielectric plate 20 and the optical axis 41 are strictly perpendicular, or may mean that the dielectric plate 20 and the optical axis 41 are close to vertical, that is, a certain angle is allowed deviation. In the present application, the dielectric plate 20 uses a near zero refractive index material, that is, the refractive index of the material forming the dielectric plate 20 is close to zero. Specifically, the absolute value of the refractive index of the dielectric plate 20 is greater than 0 and less than 1. Preferably, in some embodiments of the present application, the near-zero refractive index material is a material having an absolute refractive index greater than 0 and less than 0.1. Any two beams of electromagnetic beams transmitted into the dielectric plate 20 that are transmitted through different channels are refracted by the dielectric plate 20 and the phase difference becomes larger than before the refraction.

Referring to FIG. 3, taking the change of the phase difference of the electromagnetic beam passing through the dielectric plate 20 in FIG. 3 as an example, the principle of the amplification of the phase difference between the electromagnetic beams transmitted by the dielectric plate 20 to different channels is described. In the present application, the pair of dielectric plates 20 includes an incident surface 21 and an exit surface 22 that are opposite to each other, and a side surface 23 connected between the incident surface 21 and the exit surface 22. Since the electromagnetic beams transmitted through different channels have an angle between them, that is, the incident angles of the electromagnetic beams transmitted to the dielectric plate 20 through different channels are different. In this embodiment, first beam 21 perpendicular to the electromagnetic wave, an electromagnetic beam with the beam normal of the second surface 21 form an incident angle of θ ₁ degrees to the incident surface of the dielectric plate 20, i.e., the first beam and the second beam of electromagnetic waves The angle between the two electromagnetic beams is θ ₁ . It can be understood that, in an actual situation, the first electromagnetic beam and the second electromagnetic beam may be two electromagnetic beams that are transmitted at different angles from the dielectric plate 20 by different channels. In this application, the dielectric plate 20 is formed with a near-zero refractive index material, and its refractive index is 0 or close to 0. Therefore, the angles at which electromagnetic beams with different incident angles are refracted in the dielectric plate 20 are different, so that the electromagnetic wave The difference in the distance transmitted by the beam when passing through the dielectric plate 20 is much larger than the difference in transmission in the air, so that the phase difference of the electromagnetic beams transmitted by different channels after exiting will be compared to that entering the The dielectric plate 20 has previously become larger, that is, the dielectric plate 20 can achieve the purpose of amplifying the phase difference of the two beams of the electromagnetic beams transmitted by different channels, thereby reducing the correlation of the beams transmitted by different channels. For example, in this embodiment, the refraction angle of the first electromagnetic beam after passing through the incident surface 21 is 0, and the refraction angle of the second electromagnetic beam after passing through the incident surface 21 is θ ₂ , so that the first electromagnetic beam The distance d1 transmitted in the dielectric plate is very different from the distance d2 transmitted in the dielectric plate 20 by the second electromagnetic beam, thereby changing the phase of the first electromagnetic beam and the second electromagnetic beam after exiting the dielectric plate 20 difference. Specifically, the phase difference of the electromagnetic beam transmitted according to different channels after exiting through the dielectric plate 20 with respect to the change value before exiting meets the formula:

(Among them, Δφ refers to the change value of the phase difference of the first electromagnetic beam and the second electromagnetic beam that enter the dielectric plate 20 at different incident angles after being refracted by the dielectric plate 20, that is, through different channels The electromagnetic beam transmitted to the same dielectric plate 20; c is the speed of light, n is the refractive index of the dielectric plate 20, θ ₁ is the difference between the incident angle of the first electromagnetic beam and the incident angle of the second electromagnetic beam, h is the thickness of the dielectric plate, and ω is the circular frequency. In this application, the circular frequencies of the electromagnetic beams transmitted through different channels are the same.) It can be seen that when the refractive index n of the dielectric plate 20 approaches two beams and enters the dielectric plate 20 When the sinusoidal value of the angle θ ₁ between the electromagnetic beams in is the change value of the phase difference of the two electromagnetic beams emitted through the dielectric plate 20 can be the largest, that is, the two electromagnetic beams emitted from the dielectric plate 20 can be made The phase difference between them can be amplified as much as possible, so that the purpose of amplifying the phase difference of the electromagnetic beams transmitted by different channels can be better achieved. Since the distance between the two groups of MIMO antennas is relatively long, the angle θ ₁ between the first electromagnetic beam and the second electromagnetic beam is small, and its sine value is close to 0, and the dielectric plate 20 in this application is The near-zero refractive index material is formed, and its refractive index is 0 or close to 0, so that after being refracted by the dielectric plate 20, the phase difference between the outgoing beams refracted by the dielectric plate 20 for beams transmitted by different channels It will be amplified, so that the correlation of the electromagnetic beams transmitted by different channels can be reduced by the dielectric plate 20, and super resolution of the electromagnetic beams transmitted by different channels can be achieved.

Further, in some implementations of the present application, the side surface 23 is covered with a reflective layer 24, and the reflective layer 24 can reflect the electromagnetic beam incident on the side surface 23 to the incident surface 21 or the exit surface 22, Therefore, the electromagnetic beam does not leak from the side 23 and the loss of the electromagnetic beam signal is avoided. And, from the perspective of the correlation between the electromagnetic beams, the phase difference between different electromagnetic beams is 0 degrees and 180 degrees, and the correlation is the same. Therefore, in this application, the electromagnetic beam irradiated on the reflective layer 24 produces a phase change of 180°+Nⅹ360°, which can ensure that the electromagnetic beam reflected by the reflective layer 24 and the electromagnetic beam not reflected by the reflective layer 24 have the same phase In other words, to avoid changes in the correlation between the electromagnetic beam reflected by the reflective layer 24 and the electromagnetic beam not reflected by the reflective layer 24. In this embodiment, the reflective layer 24 is formed of a metal material, which can cause a 180° phase change of the electromagnetic beam reflected on its surface.

In this embodiment, the dielectric plate 20 has a circular plate-like structure, and the electromagnetic beam enters from the incident surface 21 and is reflected from the dielectric plate 20 and exits from the exit surface 22. In addition, the outgoing range of the electromagnetic beam is [min(h tanθ ₂ ,D _Z -h tanθ ₂ ),D _Z ], where θ ₂ is the angle between the two electromagnetic beams with different incident angles refracted in the dielectric plate 20 ; D _Z is the diameter of the dielectric plate 20.

Further, in some embodiments of the present application, the refractive index of the dielectric plate 20 is close to 0, and its dielectric constant and magnetic permeability are close to zero. In order to ensure that neither the vertically polarized waves nor the horizontally polarized waves in the electromagnetic beam are reflected by the dielectric plate 20, the dielectric plate 20 is prevented from weakening the energy of the electromagnetic beam.

Further, according to different incident angles, the first beam electromagnetic beam and the second beam electromagnetic beam incident on the dielectric plate 20 are refracted by the dielectric plate 20 and the phase difference change formula

It can be seen that the material (refractive index n) and thickness h of the dielectric plate 20 have an influence on the phase difference change value of electromagnetic beams with different incident angles before and after passing through the dielectric plate 20. Therefore, according to the material of the selected dielectric plate 20, the thickness of the dielectric plate 20 can be set to an appropriate value, so that the phase difference of the electromagnetic beam refracted by the mirror dielectric plate 20 changes the most, thereby making the phase difference at the time of incidence After almost two electromagnetic beams emerge, the phase difference can reach the maximum, thus achieving high resolution of the electromagnetic beam. Specifically, the thickness h of the dielectric plate 20 in the direction perpendicular to the incident surface 21 satisfies the formula

When the phase difference change value Δφ of the two electromagnetic beam mirrors with different incident angles after being refracted by the dielectric plate 20 is 90°, since the incident angles of the two electromagnetic beams are similar, when the two electromagnetic beams exit through the dielectric plate 20 The phase difference is close to 90°, at this time, the correlation between the two electromagnetic beams is the smallest, so that the maximum resolution of the beams can be achieved.

Please refer back to FIG. 2. In this embodiment, the antenna unit 100 is a single-reflection antenna, and the optical component 40 is a main reflector 42. The feed 10 is located between the dielectric plate 20 and the main reflector 42. The dielectric plate 20 is located between the feed 10 and the front end of the radome 30, that is, the feed 10 and The dielectric plate 20 is sequentially disposed between the main reflector 42 and the front end 31. In this embodiment, the feed source 10 is located on the optical axis 41, and the central axis of the dielectric plate 20 coincides with the optical axis 41. It can be understood that, in some embodiments of the present application, the feed source 10 may also slightly deviate from the optical axis 41, and the central axis of the dielectric plate 20 may also deviate slightly from the optical axis 41. The main reflector 42 has a concave portion, and the inner wall of the concave portion is the main reflection surface 421, and the electromagnetic beam is transmitted to the main reflection surface 421 to cause reflection. Moreover, since the main reflection surface 421 is a concave surface, the electromagnetic beams projected parallel on the main reflection surface 421 can be converged. In this embodiment, the orthographic projection of the dielectric plate 20 on the reference plane perpendicular to the optical axis 41 covers the orthographic projection of the main reflective surface 421 on the reference plane. In this embodiment, the dielectric plate 20 is a circular plate, the main reflective surface 421 is a parabolic surface, and the optical axis 41 is the center of rotation of the parabolic surface. The diameter of the dielectric plate 20 is greater than or equal to the diameter of the opening of the main reflective surface 421, so that the orthographic projection of the dielectric plate 20 on a reference surface covers the main reflective surface 421 on the reference surface Orthographic projection. It can be understood that, in other embodiments of the present application, the dielectric plate 20 may also be a plate-like structure of other shapes, for example, the dielectric plate 20 may be a square plate with a side length greater than or equal to the main The diameter of the opening of the reflecting surface 421 makes the projection of the dielectric plate 20 on the plane where the opening of the main reflecting surface 421 covers the opening of the main reflecting surface 421.

In this embodiment, the feed source 10 is located between the dielectric plate 20 and the main reflector 42, and the inner wall of the main reflection surface 421 is used to reflect the electromagnetic beam incident through the dielectric plate 20 to The feed source 10, that is, when the feed source 10 receives the electromagnetic beam, the electromagnetic beam transmitted from different channels to the feed source 10 first passes through the dielectric plate 20 and then passes through the inner wall of the main reflection surface 421 It is reflected to the feed 10 and is received by the feed 10. Further, in this embodiment, the phase center of the feed 10 is located on the central axis of the main reflection surface 421, so that all the electromagnetic beams reflected by the inner wall surface of the main reflection surface 421 can be affected by The feed 10 is received to ensure the transmission quality of the signal.

The dielectric plate 20 amplifies the phase difference of the electromagnetic beams transmitted to the feed 10 by different channels, so that the phase difference between the electromagnetic beams of the different channels received by the feed 10 is large, which can increase Correlation between electromagnetic wave speeds between widely different channels. It can be understood that, since the feed 10 can receive both electromagnetic beams and electromagnetic beams, when the feed 10 sends an electromagnetic beam, its transmission path is the same as the transmission path when the feed 10 receives an electromagnetic beam Inversely, that is, the electromagnetic beams emitted by the feed 10 are transmitted through different channels, and the electromagnetic beams transmitted through the different channels are first reflected by the inner wall of the main reflection surface 421, and then passed through the dielectric plate. 20 sent out. When the feed source 10 sends an electromagnetic beam, the electromagnetic beam emitted by the feed source 10 is reflected by the main reflection surface 421 and then becomes a parallel beam to exit from the dielectric plate 20, so that the electromagnetic beam emitted from the feed source 10 The phase difference will not change after being ejected through the dielectric plate 20.

Further, in this embodiment, the transceiver port of the feed 10 faces the inner wall of the main reflection surface 421 so that the electromagnetic beam reflected by the inner wall of the main reflection surface 421 can be directly reflected to the feed 10 The transceiver port is received by the transceiver port of the feed 10.

Please refer to FIG. 4. FIG. 4 shows another antenna unit 200 of the present application. The antenna unit 200 is a dual-reflection antenna (such as a Cassegrain antenna). In this embodiment, the difference between the antenna unit 200 and the antenna unit 100 in the embodiment of FIG. 2 is that the optical component 40 further includes a secondary reflector 43. The secondary reflector 43 is located between the dielectric plate 20 and the feed 10, and the size of the secondary reflector 43 is much smaller than the size of the primary reflector 42, so as to prevent the secondary reflector 43 from Blocking of the electromagnetic beam transmission path. Further, the sub-reflector 43 includes a sub-reflection surface 431 that faces the feed 10, and the sub-reflection surface 431 is used for further reflection of the electromagnetic beam reflected by the main reflection surface 421 and after being reflected by the sub-reflection surface 431 Of the electromagnetic beam is received by the feed 10. In this embodiment, the transceiver port of the feed 10 faces the secondary reflective surface 431.

In this embodiment, by setting the secondary reflector 43 and positioning the secondary reflector on the reflection path of the electromagnetic beam reflected from the main reflection surface 421 to the feed source 10 in the embodiment of FIG. 2, Therefore, when the electromagnetic beam is transmitted to the secondary reflector 43, it is reflected back by the secondary emitter 40 and received by the feed source 10. Therefore, it can be easily known that the sub-reflector 43 is provided in this embodiment to further reflect the electromagnetic beam reflected by the main reflection surface 421 to the feed source 10. Therefore, the antenna unit 200 of this embodiment The dimension in the direction of the axis 41 can be smaller than the dimension of the antenna unit 100 in the direction of the optical axis 41, that is, the size of the antenna unit 200 can be reduced.

Please refer to FIG. 5, which shows another antenna unit 300 of the present application. The antenna unit 300 is a lens antenna. In this embodiment, the difference between the antenna unit 300 and the antenna unit 100 in the embodiment of FIG. 2 is that in this embodiment, the optical component 40 is a refractive lens 44, and the refractive lens 44 and the dielectric plate 20 It is located between the feed 10 and the front end 31 of the radome 30 in sequence. The refractive lens 44 is used to refract the electromagnetic beam passing through the dielectric plate 20 to the feed source 10. The orthographic projection of the dielectric plate 20 on the reference plane covers the orthographic projection of the refractive lens 44 on the reference plane. In this embodiment, the refractive lens 44 converges the incident electromagnetic beam, so that the feed source 10 can receive as many electromagnetic beams transmitted by different channels as possible. Similarly, by setting the orthographic projection of the dielectric plate 20 on the reference plane perpendicular to the optical axis to cover the orthographic projection of the refractive lens 44 on the reference plane, the electromagnetic waves entering the refractive lens 44 converging to the feed 10 Both beams can be amplified by the dielectric plate 20 for phase difference and then received by the feed source 10, so that the antenna unit 300 can easily distinguish electromagnetic beams transmitted by different channels.

Please refer to FIG. 6a and FIG. 6b. In another embodiment of the present application, an antenna unit 400 is provided. The antenna unit 400 is a single reflection antenna. The difference between the antenna unit 400 and the antenna unit 100 of FIG. 2 is: The optical component 40 further includes a diverging lens 45 and a condensing lens 46. The diverging lens 45, the condensing lens 46 and the main reflector 42 are all coaxially arranged along the optical axis 41. The divergent lens 45 may be a single lens or an equivalent lens of a lens group formed by a plurality of lenses; the converging lens 46 may also be a single lens or an equivalent lens of a lens group formed by a plurality of lenses . Wherein, the equivalent lens of the lens group means that the refractive effect of the equivalent lens is the same as that of the lens group. Wherein, the lens group may only have a diverging lens or a converging lens, or may include both a diverging lens and a converging lens. For example, when the condensing lens 46 is a lens group, there may be a plurality of individual condensing lenses in the lens group, and the convergence effect of the lens group formed by the plurality of condensing lenses is equivalent to the required converging lens 46; the lens group 60 may also be a combined lens group formed by a convergent lens and a divergent lens, so that the convergent effect of the combined lens group is equivalent to the desired convergent effect of the convergent lens 46.

The dielectric plate 20 is located between the divergent lens 45 and the condensing lens 46. In addition, the central axis of the dielectric plate 20 is also coaxial with the diverging lens 45 and the condensing lens 46. The divergent lens 45 is used to convert the electromagnetic beam directed to the dielectric plate 20 into a parallel electromagnetic beam, and the convergent lens 46 is used to convert the electromagnetic beam directed from the feed source 10 to the dielectric plate 20 into The parallel electromagnetic beams, that is, through the diverging lens 45 or the converging lens 46, make the electromagnetic beams entering the dielectric plate 20 all parallel beams.

In this embodiment, the feed 10 is located on the side of the converging lens 46 away from the dielectric plate 20. The dielectric plate 20, the feed 10, the divergent lens 45 and the converging lens 46 and the main reflector 42的主反射面421.

Further, in some embodiments of the present application, the focal lengths of the converging lens 46 and the diverging lens 45 are the same, so that the propagation direction of the electromagnetic beam refracted by the converging lens 46 and the diverging lens 45 is not changes happened. Further, in this application, the distance L1 between the phase center of the feed 10 and the center of the condensing lens 46 satisfies the formula:

Where, D1 is the radius of the condensing lens 46, and θ is the half angle of the irradiation angle of the feed 10, so that the electromagnetic beam refracted by the condensing lens 46 can be completely received by the feed 10.

In this embodiment, the divergent lens 45, the dielectric plate 20, and the condensing lens 46 are sequentially located between the main reflector 42 and the feed source 10, and the signal receiving end of the feed source 10 faces the dielectric plate 20 . The electromagnetic beams transmitted from different channels are transmitted to the main reflector 42 through the front end 31 of the radome 30. The main reflector 42 reflects and converges the electromagnetic beams and passes through the main reflector 42 The reflected electromagnetic beam passes through the divergent lens 45, the dielectric plate 40, and the condensing lens 46 in sequence, and is finally received by the feed source 10. The divergent lens 45 is used to convert the electromagnetic beam reflected and converged by the main reflector 42 into a parallel beam and then pass through the dielectric plate 20, so that the phase of the electromagnetic beam transmitted through different channels of the dielectric plate 20 The difference can be amplified according to requirements; finally, the electromagnetic beam after the phase difference amplification of the dielectric plate 20 is converged to the feed source 10 through the condensing lens 46.

In this embodiment, the divergent lens 45 and the converging lens 46 convert the electromagnetic beam converged by the main reflector 42 into a parallel beam and then enter the dielectric plate 20, so that the dielectric plate 20 can be realized While changing the phase difference of the electromagnetic beams of different channels, the size of the dielectric board 20 can be reduced, the cost can be saved, and the volume of the antenna unit 400 can be reduced.

Please refer to FIG. 7. In another embodiment of the present application, an antenna unit 500 is provided. The antenna unit 500 is a dual-reflection antenna (such as a Cassegrain antenna). The antenna unit 500 is the same as the antenna unit shown in FIG. 6 a. The difference between 400 is that the optical component 40 further includes a sub-reflector 43, the divergent lens 45, the dielectric plate 20, the condensing lens 46, and the feed 10 are located in turn on the sub-reflector 43 and all Between the main reflector 42, the sub-reflector 43 includes a sub-reflection surface 431 toward the feed 10 for reflecting the electromagnetic beam reflected by the inner wall of the main reflection surface 421 to the dielectric plate 20. The diameter of the secondary reflector 43 is much smaller than the diameter of the main reflection surface 421, and the diameters of the diverging lens 45, the condensing lens 46 and the diameter of the dielectric plate 20 are much smaller than the diameter of the secondary reflector 43 The diameter is to prevent the diverging lens 45, the converging lens 46, the dielectric plate 20, and the secondary reflector 43 from blocking the transmission of the electromagnetic beam signal to the main reflecting surface 421. In this embodiment, the diameter of the dielectric plate 20 is the same as the diameter of the diverging lens 45 and the condensing lens 46. It can be understood that, in some embodiments, the diameter of the dielectric plate 20 may be slightly different from the diameters of the diverging lens 45 and the converging lens 46.

In this embodiment, by adding the secondary reflector 43 on the basis of the antenna unit 400, the secondary reflector 43 is located on the transmission path where the electromagnetic beam is transmitted from the primary reflector 42 to the feed 10, so that the slave The electromagnetic beam reflected by the main reflector 42 is transmitted to the secondary reflector 43 and then further reflected to the feed source 10. Therefore, with respect to an antenna unit (such as the antenna unit 400) where the sub-reflector 43 is not provided, providing the sub-reflector 43 can reduce the size of the antenna unit 500 along the optical axis 41 of the optical component, The volume of the antenna unit 500 is reduced.

Please refer to FIG. 8. In another embodiment of the present application, an antenna unit 600 is provided. The antenna unit 600 is a lens antenna. The difference between the antenna unit 600 and the antenna unit 400 of FIG. 6a is that the optical component 40 The refractive lens 44 is included, but the main reflector 42 is included. The condensing lens 46, the dielectric plate 20, the divergent lens 45 and the refractive lens 44 are sequentially disposed between the feed source 10 and the front end 31 of the radome 30. The refractive lens is used to radiate the electromagnetic beam passing through the front end 31 of the radome 30, converge through the refractive lens 44 and transmit to the divergent lens 45, and the divergent lens 45 converts the refractive lens 44 The converged electromagnetic beam is converted into a parallel electromagnetic beam and is directed to the dielectric plate 20. After the phase difference of the dielectric plate 20 is changed, the electromagnetic beam transmitted through different channels is condensed to the feed source 10 through the condensing lens 46. In this embodiment, the size of the refractive lens 31 is the same as the size of the front end of the radome 30, so that all electromagnetic beams incident through the front end 31 of the radome 30 can be refracted so as to be The feed 10 receives. The divergent lens 45, the condensing lens 46, and the dielectric plate 20 can all be set smaller than the size of the refractive lens 44, so as to achieve the effect while reducing the volume of the antenna unit 600 and reducing the manufacturing cost.

In this application, by providing a dielectric plate 20 in the antenna unit, the electromagnetic beams transmitted through different channels are amplified by the dielectric plate 20 for phase difference amplification before being received by the feed source 10, so that different channels after exiting from the dielectric plate 20 The phase difference between the transmitted electromagnetic beams increases, thereby reducing the correlation between the electromagnetic beams transmitted by different channels, so that the antenna unit can super-resolve the electromagnetic beams transmitted by different channels.

Please refer to FIG. 9, this application also provides a base station 200. The base station 200 may include an antenna 210, an outdoor unit (ODU) 220, an indoor unit (IDU) 230, and a cable 240. The ODU 220 and the IDU 230 can be connected by a cable 240, and the ODU 220 and the antenna 210 can be connected by a feed waveguide.

The antenna 210 may be implemented by using any one of the antenna units in the above embodiments. The antenna 210 mainly provides the directional transmission and reception function of the electromagnetic beam, and realizes conversion between the radio frequency signal generated or received by the ODU 220 and the radio frequency signal in the atmospheric space. In the transmission direction, the antenna 210 converts the radio frequency signal output by the ODU 220 into a directional electromagnetic beam, and radiates to the space through the different channel. In the receiving direction, the antenna 210 receives electromagnetic beams transmitted by different channels in the space and transmits them to the ODU 220.

The ODU 220 may include an intermediate frequency module, a sending module, a receiving module, a multiplexer, a duplexer, and so on. ODU 220 mainly provides the conversion function between the intermediate frequency analog signal and the radio frequency signal. In the transmission direction, ODU 220 up-converts and amplifies the intermediate frequency analog signal from IDU 230, converts it into a radio frequency signal of a specific frequency, and sends it to antenna 210. In the receiving direction, ODU 220 down-converts and amplifies the radio frequency signal received from antenna 210, converts it to an intermediate frequency analog signal, and sends it to IDU 230.

IDU 230 can include single-board types such as main control switching clock board, intermediate frequency board, and service board, and can provide Gigabit Ethernet (GE) services and synchronous transfer mode-1 (synchronous transfer module-1, STM-1) services Interface with multiple services such as E1 services. IDU 230 mainly provides the baseband processing of business signals, the conversion between baseband signals and intermediate frequency analog signals. In the transmission direction, IDU 230 modulates the baseband digital signal into an intermediate frequency analog signal. In the receiving direction, IDU 230 demodulates and digitizes the received intermediate frequency analog signal and decomposes it into a baseband digital signal.

In this application, since the antenna unit of the antenna 210 can distinguish the electromagnetic beams transmitted by different channels well, that is, the antenna 210 can clearly distinguish different radio frequency signals, so that the base station 200 has good signal transmission effect.

The present application also provides a communication system including at least two of the base stations 200, and two adjacent base stations 200 perform communication through electromagnetic beams transmitted between different antenna units. In this application, the base station 200 has a good signal transmission effect, that is, it can also have a good communication effect between the communication systems.

The above are only the specific embodiments of the present invention, but the scope of protection of the present invention is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present invention. It should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

A multi-input multi-output antenna with at least two receiving channels, characterized by comprising a plurality of antenna units, each of which includes:

A radome with a front end;

A feed source, which is provided in the radome and used to receive the electromagnetic beam passing through the front end;

An optical component provided in the radome for converging the electromagnetic beam passing through the front end to the feed source, the optical component including an optical axis;

A dielectric plate, the dielectric plate is disposed in the radome, the dielectric plate is disposed perpendicular to the optical axis; the electromagnetic beam is transmitted to the feed via the dielectric plate; the dielectric plate is a refractive index The absolute value of is greater than 0 and less than 1; the dielectric plate is used to increase the phase difference of any two electromagnetic beams received from different channels of the at least two receiving channels.
The multiple-input multiple-output antenna according to claim 1, wherein the absolute value of the refractive index of the dielectric plate is greater than 0 and less than 0.1.
The multiple-input multiple-output antenna according to claim 1 or 2, wherein the dielectric plate includes an incident surface and an exit surface disposed opposite to each other, and a side surface connected between the incident surface and the exit surface , The side surface is covered with a reflective layer, and the reflective layer is used to reflect the electromagnetic beam directed to the side surface to the exit surface, and make the reflected electromagnetic beam compare to that before reflection The electromagnetic beam produces a phase change of 180°+Nⅹ360°, where N is a natural number.
The multiple input multiple output antenna according to any one of claims 1 to 3, wherein the thickness h of the dielectric plate in a direction perpendicular to the incident surface satisfies the formula
Where Δφ refers to the change value of the phase difference of the first and second electromagnetic beams transmitted by different channels after being refracted by the dielectric plate compared to the phase difference before refraction; c is the speed of light and n is The refractive index of the dielectric plate, θ 1 is the difference between the incident angle of the first electromagnetic beam and the incident angle of the second electromagnetic beam, and ω is the circular frequency of the incident electromagnetic beam.
The multiple-input multiple-output antenna according to claim 4, wherein the phase difference of the two electromagnetic beams transmitted through different channels after being refracted by the dielectric plate is 90° different from the phase difference before the refraction.
The multiple-input multiple-output antenna according to any one of claims 1 to 5, wherein the optical component includes a main reflector, and the feed and the dielectric plate are sequentially located on the main reflector and the Between the front ends of the radome, the main reflector has a main reflection surface, and the dielectric plate faces the main reflection surface, and the main reflection surface is used to reflect the electromagnetic beam incident through the dielectric plate; The orthographic projection of the dielectric plate on the reference plane perpendicular to the optical axis covers the orthographic projection of the main reflective surface on the reference plane.
The multiple-input multiple-output antenna according to claim 6, wherein the optical component further includes a secondary reflector, the secondary reflector is located between the dielectric plate and the feed source, and the secondary reflector It includes a secondary reflection surface toward the feed, and the secondary reflection surface is used to reflect the electromagnetic beam reflected by the main reflection surface to the feed.
The multi-input multi-output antenna according to any one of claims 1-5, wherein the optical component includes a refractive lens, and the refractive lens and the dielectric plate are sequentially located on the feed source and the radome Between the front ends of the, the refractive lens is used to refract the electromagnetic beam passing through the dielectric plate to the feed; the orthographic projection of the dielectric plate on the reference plane perpendicular to the optical axis covers the The orthographic projection of the refractive lens on the reference plane.
The multiple-input multiple-output antenna according to any one of claims 1 to 5, wherein the optical component includes a main reflector, a diverging lens, and a condensing lens;

The diverging lens is arranged coaxially with the converging lens, the dielectric plate is located between the diverging lens and the converging lens, and the diverging lens is used to convert the electromagnetic beam directed to the dielectric plate into parallel An electromagnetic beam, and the converging lens is used to convert the electromagnetic beam emitted from the feed to the dielectric plate into a parallel electromagnetic beam;

The feed is located on the side of the converging lens away from the dielectric plate, the main reflector has a main reflecting surface, the dielectric plate, the feed, the divergent lens and the converging lens and facing the main reflecting surface, so The main reflection surface is used to reflect the incident electromagnetic beam to the dielectric plate.
The multiple input multiple output antenna according to claim 9, wherein the focal length of the converging lens and the diverging lens are the same.
The multiple-input multiple-output antenna according to claim 9 or 10, wherein the divergent lens, the dielectric plate, and the converging lens are sequentially disposed between the main reflector and the feed source.
The multi-input multi-output antenna according to claim 9 or 10, wherein the optical component further includes a sub-reflector, the divergent lens, the dielectric plate, the convergent lens, and the feed are provided in this order Between the sub-reflector and the main reflector, the sub-reflector includes a sub-reflection surface toward the feed, and the sub-reflection surface is used to reflect the electromagnetic beam reflected by the main reflection surface to The dielectric board.
The multi-input multi-output antenna according to claim 12, wherein the diameters of the divergent lens, the converging lens, and the diameter of the dielectric plate are smaller than the diameter of the sub-reflector.
The multiple-input multiple-output antenna according to any one of claims 1 to 5, wherein the optical components include a refractive lens, a diverging lens, and a condensing lens; the refractive lens, the diverging lens, the dielectric plate, and all The converging lens is sequentially arranged along the optical axis between the front end of the radome and the feed; the refractive lens is used to converge the electromagnetic beam passing through the front end of the radome, and the diverging lens is used In order to convert the electromagnetic beam condensed by the refractive lens into a parallel electromagnetic beam and emit it to the dielectric plate, the converging lens is used to condense the electromagnetic beam passing through the dielectric plate to the feed source.
A base station, characterized by comprising the multiple-input multiple-output antenna according to any one of claims 1-14.
A communication system, characterized in that it includes at least two base stations as claimed in claim 15, and two adjacent base stations perform communication.