JP2012070210A - Antenna system, relay station, and wireless communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve wireless communication characteristics at a low cost without making the number of antennae increase.SOLUTION: In an antenna system 1, a route of a signal is changed by a signal branch device 3, and a phase amount which phase shifters 4to 4apply is changed. The phase shifters 4to 4give each different phase change to n signals, and thereby, a directivity pattern of an antenna 2 is changed. The phase change amount of phase shifters 4to 4is set by phase shift change data etc. in advance so that a desired antenna directivity pattern may be acquired. A signal output from power distribution/composition devices 5to 5becomes a signal received by the antenna 2 having the antenna directivity pattern corresponding to the phase change amount set to the phase shifters 4to 4, and a signal input to power distribution/composition devices 5to 5is transmitted by the antenna 2 having the antenna directivity pattern corresponding to the phase change amount set to the phase shifters 4to 4.

Description

  The present invention relates to a technique for improving communication characteristics in wireless communication, and more particularly to a technique effective for improving the performance of an antenna used for wireless communication.

  In wireless communication in which a base station and a terminal communicate with each other, a wireless signal is attenuated according to the distance from the base station to the terminal, so that communication characteristics deteriorate at a terminal far from the base station. In addition, when a terminal located between the first base station and the second base station receives a radio signal transmitted from the first base station, the radio signal transmitted from the second base station is also an interference signal. In this case, the communication characteristics also deteriorate. In order to solve these problems, it is considered to arrange a relay station.

  The relay station receives a signal transmitted from the base station (hereinafter referred to as a donor station), generates a new signal based on the signal, and transmits the generated signal to the terminal. The communication partner of the relay station is both the donor station and the terminal, and both are located in different directions when viewed from the relay station.

  Therefore, it is possible to improve the communication performance between the relay station and the donor station or between the relay station and the terminal by switching the antenna directivity of the relay station according to the communication partner.

  As a technique for improving the communication performance of a directional antenna in this type of relay station, for example, a base station side antenna that transmits and receives radio waves to and from a base station is configured by a horizontal stack antenna, and the base station side antenna Is an antenna having a high antenna gain and a sharp directivity compared to a terminal-side antenna that transmits and receives radio waves to and from a portable terminal (see, for example, Patent Document 1), or any of a plurality of antenna units One or more antenna units are selected, and an arbitrary antenna directivity is set for the selected antenna unit (see, for example, Patent Document 2).

JP 2009-239874 A JP-A-11-261474

  However, the present inventor has found that there are the following problems in the technology for improving the communication characteristics by switching the directivity of the antenna using the relay station as described above.

  That is, as described above, since the donor station and the terminal are located in different directions when viewed from the relay station, it is necessary to separately prepare an antenna that communicates with the donor station and an antenna that communicates with the terminal.

  As a result, the number of antennas installed in the relay station increases, and there is a problem that the cost increases significantly.

  An object of the present invention is to provide a technique capable of improving wireless communication characteristics at low cost without increasing the number of antennas.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the inventions disclosed in the present application, the outline of typical ones will be briefly described as follows.

  The present invention relates to an antenna unit composed of a plurality of antenna elements, a signal branching unit that splits the paths of the signal sets received by the plurality of antenna elements into m sets, with the signals received by the plurality of antenna elements as one signal set. , M phase shifters that respectively change the phase of the signal branched by the signal branching unit based on phase change amount data, and power for combining the m signals output from the phase shifter into one signal And a distributor / combiner, and a signal output from the power distributor / combiner is formed into an antenna directivity pattern corresponding to a communication destination.

  Further, the present invention is a relay station that receives a signal transmitted by a base station, generates a new signal based on the signal, and transmits the generated signal to a communication destination terminal. The antenna system has an antenna unit including a plurality of antenna elements, a signal received by the plurality of antenna elements as one signal set, and m sets of paths of the signal sets received by the plurality of antenna elements. A signal branching device branching into two, m phase shifters for changing the phase of the signal branched by the signal branching device based on phase change data, and m signals output from the phase shifting device. The antenna system includes a power distributor / combiner that combines signals into one signal, and the antenna system forms a signal output from the power distributor / combiner in the shape of an antenna directivity pattern corresponding to a communication destination.

  Furthermore, the present invention receives a base station as a signal transmission / reception source, a signal transmitted by the base station, generates a new signal based on the signal, and transmits the generated signal to a communication destination terminal. The relay station includes an antenna system, and the antenna system includes an antenna unit including a plurality of antenna elements and a signal received by the plurality of antenna elements as one signal. A signal branching device that branches the path of a signal set received by a plurality of antenna elements into m pairs, and m shifts that respectively change the phase of the signal branched by the signal branching device based on the phase change amount data. A phase shifter and a power distributor / combiner that combines the m signals output from the phase shifter into one signal, and the antenna system receives the signal output from the power distributor / combiner as a communication destination Corresponding to And it forms the shape of the antenna directivity pattern.

  Furthermore, the outline | summary of the other invention of this application is shown briefly.

  The present invention comprises an antenna composed of a plurality of antenna elements, a signal branching device, and a plurality of phase shifters, and the signal branching device branches into a plurality of signal paths connected to the respective antenna elements. Changes the phase of a signal passing through a plurality of signal paths, thereby realizing directivity switching corresponding to the communication partner.

  Among the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows.

  (1) Directivity switching corresponding to each communication partner can be performed without increasing the number of antennas.

  (2) The above (1) can be expected to reduce the number of antennas and the installation area of the antenna, so that the installation cost of the antenna system can be reduced.

  (3) Further, by forming appropriate signal directivity, the communication speed can be increased and the communication quality can be stabilized.

It is a block diagram which shows an example of the antenna system by Embodiment 1 of this invention. It is explanatory drawing which shows an example which applied the antenna system of FIG. 1 to cellular radio | wireless communication. It is explanatory drawing which shows the other example which applied the antenna system of FIG. 1 to cellular radio | wireless communication. It is a block diagram which shows an example of the antenna system by Embodiment 2 of this invention. FIG. 5 is a block diagram showing an example of an antenna system according to Embodiment 3 of the present invention. It is explanatory drawing which shows an example at the time of applying the antenna system of FIG. 5 to frequency conversion resending. It is a block diagram which shows an example of the antenna system by Embodiment 4 of this invention. It is explanatory drawing which shows an example which applied the antenna system of FIG. 7 to the relay station which operate | moves by frequency division duplex. It is a block diagram which shows an example of the antenna system by Embodiment 5 of this invention. It is a block diagram which shows an example of the antenna system by Embodiment 6 of this invention. It is a flowchart which shows an example of switch switching control in the antenna system of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

(Embodiment 1)
FIG. 1 is a block diagram illustrating an example of an antenna system according to Embodiment 1 of the present invention, FIG. 2 is an explanatory diagram illustrating an example in which the antenna system of FIG. 1 is applied to cellular radio communication, and FIG. It is explanatory drawing which shows the other example which applied the antenna system to cellular radio | wireless communication.

In the first embodiment, the antenna system 1 includes an antenna 2, a signal branching unit 3, phase shifters 4 ₁ to 4 _m , and power distribution / combining units 5 _{1 to} 5 _m, as shown in FIG. Yes. The antenna 2 serving as an antenna unit is composed of a plurality of antenna elements 2 ₁ to 2 _n as seen in the cellular radio base station antenna. However, the n antenna elements 2 ₁ to 2 _n do not need to be installed at the same position, and one antenna 2 may be configured by combining antenna elements installed at distant positions. A set of n signals is used as a signal set, and the antenna 2 outputs one signal set.

The signal branching device 3 branches the signal set of the antenna 2 into m signal sets. The phase shifters 4 ₁ to 4 _m give different phase changes to the signals in the signal sets corresponding to the _n antenna elements 2 ₁ to 2 _n . The power distributor / combiners 5 _{1 to} 5 _m distribute one signal to n signals to generate a signal set, or combine n signals in the signal set into one signal.

The phase shifters 4 ₁ to 4 _m include components that branch signals, such as a power distributor / combiner, a duplexer, a directional coupler, or a switch. The power distribution ratio of the power distribution / combiners 5 _{1 to} 5 _m is not necessarily equal power distribution, and may be arbitrarily designed.

  Although m signal lines can be obtained from the antenna system 1 in FIG. 1, the signal lines may be collected into a smaller number of signal lines using, for example, a signal branching unit.

By configuring the antenna system 1 as shown in FIG. 1, the signal path can be changed by the signal branching device 3, and the phase change amount applied by the phase shifters 4 ₁ to 4 _m can be changed. The phase shifter 4 ₁ to 4 _m can change the directivity pattern of the antenna 2 by giving different phase changes to n signals in the signal set.

The phase change amounts of the phase shifters 4 ₁ to 4 _m are set in advance by phase change amount data or the like. Since a typical phase shifter changes the phase of a signal according to the path length of the signal transmission path, setting the phase change amount adjusts the length of the signal transmission path. The phase change amount data is a phase change amount calculated in advance by design or the like so that the antenna directivity pattern of the antenna 2 becomes a desired pattern.

As described above, the signal output from the power distributor / combiners 5 _{1 to} 5 _m is a signal received by the antenna 2 having the antenna directivity pattern corresponding to the phase change amount set in the phase shifters 4 ₁ to 4 _m. The signals input to the power distributor / combiners 5 _{1 to} 5 _m are transmitted by the antenna 2 having an antenna directivity pattern corresponding to the phase change amount set in the phase shifters 4 ₁ to 4 _m .

  FIG. 2 is an explanatory diagram showing an example in which the antenna system 1 is applied to cellular wireless communication.

FIG. 2 shows a wireless communication system including a donor station 6 serving as a base station and a relay station 7 and wireless communication of terminals 8 ₁ to 8 ₃ . A donor station 6 is provided on the left side of FIG. 2, and a relay station 7 is provided on the right side of FIG.

The relay station 7 receives a signal transmitted from the donor station 6 which is a base station as a base, generates a new signal based on the signal, and transmits the generated signal to a terminal 8 such as a mobile phone. It is sent to the _{1-8 3.} The communication partner of the relay station is both the donor station and the terminal, and both are located in different directions when viewed from the relay station.

  An antenna system 1 is installed above the donor station 6, and an antenna system 1 a is installed above the relay station 7. Here, the antenna system 1a has the same configuration as the antenna system 1 (FIG. 1).

  In FIG. 2, fan-shaped patterns indicated by dotted lines below and on the right side of the antenna system 1 of the donor station 6 indicate directivity patterns 9 and 10 in the antenna system 1, respectively.

  Further, fan-shaped patterns indicated by dotted lines below and on the left side of the antenna system 1a of the relay station 7 indicate directivity patterns 11 and 12 in the antenna system 1a, respectively.

  When the donor station 6 and the relay station 7 communicate with an arbitrary terminal, the terminal position is likely to be lower than the position of the antenna systems 1 and 1a. The pattern should be turned down.

  When the donor station 6 and the relay station 7 communicate with each other, the directivity pattern should be oriented horizontally like the directivity patterns 9 and 11 because the antenna position of each other is high.

The antenna system 1 of FIG. 1 in which the phase shift amount of the phase shifters 4 ₁ to 4 _m and the power distribution ratio of the power distributor / combiners 5 _{1 to} 5 _m are designed so as to realize the above two directivity patterns. By using it, communication speed can be increased and communication quality can be stabilized.

  FIG. 3 is an explanatory diagram showing another example in which the antenna system 1 of FIG. 1 is applied to cellular radio communication.

FIG. 3 shows the wireless communication system including the donor station 6 and the relay station 7 and the wireless communication of the terminals 8 ₁ and 8 ₂ , and shows the positional relationship in the horizontal direction. Further, the dotted fan-shaped patterns shown on the right side and the left side of the relay station 7 represent the directivity patterns 12 and 13 of the antenna of the relay station 7, respectively.

As shown in the figure, when the terminals 8 ₁ and 8 ₂ communicating with the relay station 7 are located in the opposite direction to the donor station 6, the relay station 7 determines the horizontal directivity pattern according to the communication partner. The communication performance can be improved by switching 12 or the directivity pattern 13.

The antenna system 1 (FIG. 1) which designed the phase change amount of the phase shifters 4 ₁ to 4 _m and the power distribution ratio of the power distributor / combiners 5 _{1 to} 5 _m so as to realize these directivity patterns 12 and 13 By using, communication speed can be increased and communication quality can be stabilized.

  The cellular wireless communication has been described above as an example, but the present invention is not limited thereto. For example, it can be applied to wireless communication such as television broadcasting.

(Embodiment 2)
FIG. 4 is a block diagram showing an example of an antenna system according to Embodiment 2 of the present invention.

In the second embodiment, the antenna system 1 includes an antenna 2, a directional coupler 14, phase shifters 4 ₁ and 4 ₂ , power distribution / combiners 5 ₁ and 5 ₂ , and signals as shown in FIG. It consists of a processor 15.

The antenna 2 includes a plurality of antenna elements 2 ₁ to 2 _n as in FIG. 1 of the first embodiment. The antenna 2 receives a radio signal. The directional coupler 14 transmits a signal set received by the antenna 2 to the phase shifter 4 _1.

Phase shifter 4 _1, directivity pattern during reception rotates the phase of the signal so as to correspond to the direction 1 (in FIG. 4 'direction-1'). Power divider / combiner 5 ₁ synthesizes the n output signals of the signal set in the output from the phase shifter 4 _1.

Signal processor 15 processes the output signal of the power distributor / combiner 5 ₁ to generate and output a further transmission signal. Power divider / combiner 5 ₂ outputs a signal set by distributing the output signal of the signal processor 15 into n. Phase shifter 4 _2, directivity pattern during transmission rotates the phase of the signal so as to correspond to the direction 2 (in FIG. 4 'direction-2').

The directional coupler 14 transmits the output signal set to the phase shifter 4 ₂ antenna 2. The antenna 2 transmits the signal transmitted from the directional coupler 14.

  If such a configuration is used, the path is switched depending on the direction of signal transmission, that is, the difference in transmission and reception, depending on the operation of the directional coupler 14, so that the directivity pattern at the time of reception and the transmission time at the time of transmission are used while using one antenna 2. It becomes possible to design directivity patterns separately. This is suitable for application to broadcasting by wireless communication, for example.

Here, in FIG. 3 shown in the first embodiment, it is assumed that the donor station 6 is transmitting a broadcast radio wave and the relay station 7 retransmits toward the terminal 8 ₁ (, 8 ₂ ). In this case, communication from the terminal 8 ₁ (, 8 ₂ ) to the relay station 7 and communication from the relay station 7 to the donor station 6 do not occur.

Then, the relay station 7 receives only the radio wave transmitted from the donor station 6, and the relay station 7 transmits only the radio wave directed to the terminal 8 ₁ (, 8 ₂ ). Therefore, the direction 1 in FIG. 4 ('direction-1' in FIG. 4) is the direction from the relay station 7 to the donor station 6, and the directivity pattern at the time of reception is made to correspond to the directivity pattern 12.

Further, the direction 2 in FIG. 4 (“direction-2” in FIG. 4) is the direction from the relay station 7 to the terminal 8 ₁ (, 8 ₂ ), and the directivity pattern at the time of transmission is made to correspond to the directivity pattern 13. With this configuration, the antenna system 1 can realize a directivity switching antenna that does not require dynamic control.

  The processing contents of the signal processor 15 include amplification of a signal attenuated by spatial propagation, signal equalization for restoring a signal waveform distorted by spatial propagation, and transmission of the relay station 7 itself mixed in the received signal of the relay station 7 By including a function such as signal removal, transmission characteristics can be improved.

  It is also possible to remove interference signals and noise by error correction decoding by digital signal processing, and reconfigure and transmit the signal.

(Embodiment 3)
FIG. 5 is a block diagram showing an example of an antenna system according to Embodiment 3 of the present invention, and FIG. 6 is an explanatory diagram showing an example when the antenna system of FIG. 5 is applied to frequency conversion retransmission.

In the third embodiment, as shown in FIG. 5, the antenna system 1 includes an antenna 2 composed of a plurality of antenna elements 2 ₁ to 2 _n , a duplexer 16, phase shifters 4 ₁ and 4 ₂ , power distribution / It comprises synthesizers 5 ₁ and 5 ₂ and a signal processor 15.

Demultiplexer 16, the signal set from the antenna 2, to extract a signal set of one carrier frequency freq1 connected to the phase shifter 4 _1, phase shifter extracts a signal set of the other carrier frequencies freq2 4 Connect to ₂ .

Phase shifter 4 ₁ rotates the phase of the signal as the directional pattern of the signal of the carrier frequency freq1 corresponds to the first direction direction-1.

Phase shifter 4 ₂ rotates the phase of the signal as directivity pattern of the signal of the carrier frequency freq2 corresponds to the second direction direction-2.

The power distributor / combiners 5 ₁ and 5 ₂ respectively distribute one signal to n signals to generate a signal set, or combine n signals in the signal set into one signal. The signal processor 15 processes the output signals of the power distributor / combiners 5 ₁ and 5 ₂ , and further generates and outputs a transmission signal.

  If such a configuration is used, the path is switched due to the difference in the carrier frequency of the signal by the operation of the duplexer 16, and therefore the directivity pattern of the signal having a different carrier frequency can be designed separately while using the same antenna. It becomes possible. This is suitable for application to frequency conversion retransmission in wireless communication, for example.

  FIG. 6 is an explanatory diagram showing an example in which the antenna system 1 of FIG. 5 is applied to frequency conversion retransmission.

  From the left side to the right side of FIG. 6, a donor station 6, a relay station 7, a relay station 7a, and a terminal 8 are arranged. The donor station 6, the relay station 7, and the relay station 7a constitute a radio communication system.

  The donor station 6 transmits a signal at the carrier frequency freq1, and the relay station 7 receives the signal. The relay station 7 converts the received signal of the carrier frequency freq1 into a signal of the carrier frequency freq2 and transmits it, and the relay station 7a receives it. Then, the relay station 7a converts the received signal of the carrier frequency freq2 into a signal of the carrier frequency freq1 and transmits it, and the terminal 8 receives it.

  Here, it is desirable that the relay stations 7 and 7a form different directivity patterns with respect to the signals of the two carrier frequencies freq1 and freq2, and this is determined by the configuration of the antenna system 1 shown in the third embodiment. Can be achieved.

  In addition to carrier frequency conversion, the processing content of the signal processor 15 includes an increase in signals attenuated by spatial propagation and signal equalization that restores a signal waveform distorted by spatial propagation to improve transmission characteristics. be able to.

  It is also possible to remove interference signals and noise by error correction decoding by digital signal processing, and reconfigure and transmit the signal. In FIG. 5, the duplexer 16 separates signals of two carrier frequencies, but a configuration of separating signals of three or more carrier frequencies is also conceivable.

(Embodiment 4)
FIG. 7 is a block diagram showing an example of an antenna system according to Embodiment 4 of the present invention, and FIG. 8 is an explanatory diagram showing an example in which the antenna system of FIG. 7 is applied to a relay station operating with frequency division duplex. .

In the fourth embodiment, the antenna system 1 includes an antenna 2 composed of a plurality of antenna elements 2 ₁ to 2 _n , a duplexer 16, directional couplers 17 ₁ and 17 ₂ , a phase shift, as shown in FIG. vessel ₄₁ to _4, and a power divider / combiner 5 ₁ to 5 _4.

The duplexer 16 extracts the signal set of the carrier frequency freq1 from the signal set of the antenna 2 and connects it to the directional coupler 17 ₁ , extracts the signal set of the carrier frequency freq2 and sends it to the directional coupler 17 ₂ . Connecting.

The directional coupler 17 _1, transmits a signal set transmitted from the demultiplexer 16 to the phase shifter 4 _1, it transmits a signal set transmitted from the phase shifter 4 ₂ demultiplexer 16. The directional coupler 17 ₂ transmits the signal set transmitted from the branching filter 16 to the phase shifter 4 _3, and transmits the signal set transmitted from the phase shifter 4 ₄ to the branching filter 16.

The phase shifters 4 ₁ to 4 ₄ rotate the phase of the signal so that the directivity patterns correspond to the directions direction-1, direction-2, direction-3, and direction-4, respectively.

The power distributor / combiners 5 ₁ and 5 ₃ synthesize and output n output signals in the output signal sets of the phase shifters 4 ₁ and 4 ₃ , respectively. Further, the power distributor / combiners 5 ₂ and 5 ₄ respectively distribute and output n input signals to generate signal sets, which are input to the phase shifters 4 ₂ and 4 ₄ .

By using such a configuration, the path is switched by the difference in signal carrier frequency and transmission / reception by the operations of the duplexer 16 and the directional couplers 17 ₁ and 17 ₂ , so that the carrier can be used while using the same antenna. The directivity pattern of the signal can be designed separately according to the difference in frequency and transmission / reception.

  This is suitable, for example, for application to a relay station in frequency division duplex wireless communication. FIG. 8 is an explanatory diagram showing an example in which the antenna system 1 of FIG. 7 is applied to a relay station that operates in frequency division duplex.

  In FIG. 8, the donor station 6, the relay station 7, and the terminal 8 are shown from the left side to the right side. The relay station 7 relays the signal transmitted by the donor station 6 and the terminal 8 receives it. Conversely, the relay station 7 relays the signal transmitted by the terminal 8 and the donor station 6 receives it.

  Here, the direction of communication from the donor station 6 to the terminal 8 is referred to as downlink, and the direction of communication from the terminal 8 to the donor station 6 is referred to as uplink. In frequency division duplex, radio waves having different carrier frequencies (respectively f_down and f_up) are used in the downlink and uplink.

  In FIG. 8, a carrier frequency f_down indicates a carrier frequency in the downlink, and a carrier frequency f_up indicates a carrier frequency in the uplink.

Carrier frequency of the signal relay station 7 receives from the donor station 6 is a carrier frequency F_down, the received signal passes through the phase shifter 4 ₁ and the power distributor / combiner 5 _1. Therefore, it is preferable to form a directivity pattern with the direction direction-1 (FIG. 7) as the direction from the relay station 7 to the donor station 6.

  Similarly, direction direction-1 and direction direction-4 (FIG. 7) are directed from relay station 7 to donor station 6, and direction direction-2 (FIG. 7) and direction direction-3 (FIG. 7) are relayed. The direction from the station 7 to the terminal 8 may be set.

  Thereby, according to the present embodiment, it becomes possible to switch the directivity pattern of the relay station antenna in frequency division duplex without increasing the number of antennas, and the communication characteristics can be improved.

  Further, although the duplexer 16 in FIG. 7 separates the signals of the two carrier frequencies freq1 and freq2, a configuration in which the signal is separated into signals of three or more carrier frequencies is also conceivable. Further, in the above description, the direction direction-1 and the direction direction-4, and the direction direction-2 and the direction direction-3 are set in the same direction, but the present invention does not limit the direction of the directivity pattern. .

(Embodiment 5)
FIG. 9 is a block diagram showing an example of an antenna system according to Embodiment 5 of the present invention.

In the fifth embodiment, as shown in FIG. 9, the antenna system 1 includes an antenna 2 composed of a plurality of antenna elements 2 ₁ to 2 _n , demultiplexers 16 and 19, directional couplers 17 and 18, phase shifters. It comprises devices 4 ₁ and 4 ₂ and power distributor / combiners 5 ₁ and 5 ₂ .

The duplexer 16 branches the signal set of the antenna 2 into a signal set of carrier frequencies freq 1 and freq 2 and connects it to the directional coupler 17. The directional coupler 17 transmits the signal sets input from the branching filter 16 and the phase shifters 4 ₁ and 4 ₂ to each other according to the direction.

The phase shifters 4 ₁ and 4 ₂ rotate the phase of the signal so that the directivity patterns correspond to the directions direction-1 and direction-2, respectively. The power distributor / combiners 5 ₁ and 5 ₂ synthesize the n output signals in the output signal sets of the phase shifters 4 ₁ and 4 ₂ , respectively, or distribute one signal into n signals to generate signals. Create a tuple.

The directional coupler 18 transmits signals input from the duplexer 19 and the power distributor / combiners 5 ₁ and 5 ₂ to each other according to the direction. The duplexer 16 branches an input signal from the outside into signals of the carrier frequency freq 1 and the carrier frequency freq 2 and connects to the directional coupler 18.

When the antenna system 1 shown in the fourth embodiment is applied to a relay station that operates in frequency division duplex, the direction directions-1, the direction direction-4, and the direction direction-2 in FIG. And direction direction-3 are the same, and it is necessary to prepare components having the same characteristics in the corresponding phase shifters 4 ₁ to 4 ₄ and power distribution / combiners 5 _{1 to} 5 ₄ .

On the other hand, in the antenna system 1 shown in FIG. 9, the phase shifters 4 ₁ and 4 ₂ and the power distributor / combiners 5 ₁ and 5 _{2 having} the same characteristics can be avoided and the number of parts can be reduced. Can do.

  In addition, the directional coupler 18 and the duplexer 19 play a role of combining an interface with the outside into one signal line. In particular, when the control device of the relay station is installed at a location far from the antenna, only one signal line needs to be installed, so that the installation cost can be reduced.

(Embodiment 6)
10 is a block diagram showing an example of an antenna system according to Embodiment 6 of the present invention, and FIG. 11 is a flowchart showing an example of switch switching control in the antenna system of FIG.

In the sixth embodiment, the antenna system 1 includes an antenna 2 composed of a plurality of antenna elements 2 ₁ to 2 _n , switches 20 and 21, phase shifters 4 ₁ to 4 _m , and power distribution as shown in FIG. / Synthesizer 5 _{1 to} 5 _m .

  The antenna system 1 is connected to a control device 22 of a relay station. The control device 22 includes a signal processing unit 23, a synchronization unit 24, and a control unit 25.

The switch 20 switches the connection between the signal set of the antenna 2 and the m phase shifters 4 ₁ to 4 _m in accordance with a control signal from the control device 22. The phase shifters 4 ₁ to 4 _m give different phase changes to the signals corresponding to the antenna elements 2 ₁ to 2 _n , respectively.

The power distributor / combiners 5 _{1 to} 5 _m distribute one signal to n signals to generate a signal set, or combine n signals in the signal set into one signal. The switch 21 switches connection of m signals to the power distributor / combiners 5 _{1 to} 5 _m and a signal to the control device 22 in accordance with a control signal from the control device 22.

  In the control device 22, the signal processing unit 23 restores the received signal and generates the transmission signal, and the synchronization unit 24 performs synchronization processing between the control device 22 and the wireless communication system, and the control unit 25 switches the switches 20 and 21. Generation control signal and switching control of transmission / reception operation of the signal processing unit 23 are performed.

  If such a configuration is used, the signal path is switched by switching the switches 20 and 21, so that the directivity pattern of the signal can be designed separately while using the same antenna 2.

  For example, the directivity pattern can be switched actively by performing switching control in the control device 22. In a relay station employing time division duplex wireless communication, directivity pattern switching by branching using a duplexer or a directional coupler is difficult. However, as shown in the sixth embodiment, the switch 20, In the configuration using 21, the change can be made by switching the directivity pattern according to time.

  FIG. 11 is a flowchart illustrating an example of switch switching control in the antenna system 1 illustrated in FIG. 10.

  In a wireless communication system, since each wireless station needs to operate in synchronization, a base station (donor station) transmits a signal called a synchronization signal or a synchronization channel. Based on this signal, the relay station synchronizes operation with the donor station (step S101).

  The synchronization unit 24 in FIG. 10 performs this synchronization processing. When synchronization is established, it is necessary to acquire timing for switching the switches 20 and 21. This timing corresponds to the timing of switching the communication partner of the relay station between the donor station and the terminal. The method of determining this timing differs for each standard specification of wireless communication.

  For example, when it is determined by a time fixed with respect to the time of the synchronization signal described above, the control unit 25 (FIG. 10) counts the time from the synchronization time and immediately before reaching the time, the switch 20, It is sufficient to generate 21 switching signals.

  Alternatively, when the switching timing is notified as a part of the control signal from the donor station, the signal processing unit 23 (FIG. 10) restores the control signal to obtain the switching timing, and the control is performed based on the information. The unit 25 may generate a switching control signal for the switches 20 and 21.

  With the above technique, a synchronization signal acquired from the donor station or a control signal including switching timing information is acquired, and switching timing is acquired from the information (step S102). Thereafter, the data signal from the donor station is received to generate a reproduction signal (step S103), and the directivity is switched by switching the switches 20 and 21 according to the acquired timing (step S104), toward the terminal. Send a data signal.

  Further, a data signal is received from the terminal to generate a reproduction signal (step S105), and the directivity is switched by switching the switches 20 and 21 according to the acquired timing (step S106), and the data signal is sent to the donor station. Send. Thereafter, the operation is repeated.

  In FIG. 10, the configuration in which the directivity pattern is switched using only the switches 20 and 21 is shown. However, not only the switch but also the configuration in which the directivity pattern is switched by combining the duplexer, the directional coupler, and the switch, It can be configured similarly.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.

  The present invention is suitable for a technique for improving wireless communication characteristics in an antenna system used for a relay station or a base station.

1 antenna system 1a antenna system 2 antenna 2 ₁ to 2 _n antenna element 3 signal branching unit 4 ₁ to 4 _m phase shifter 5 _{1 to} 5 _m power distributor / combiner 6 donor station 7 relay station 7a relay station 8 terminal 8 ₁ 8 ₃ terminal 9 directivity pattern 10 directivity pattern 11 directivity pattern 12 directivity pattern 13 directivity pattern 14 directional coupler 15 signal processor 16 duplexer 17 directional coupler 17 _1, 17 ₂ directional coupler 18 Directional coupler 19 Demultiplexer 20 Switch 21 Switch 22 Controller 23 Signal processor 24 Synchronizer 25 Controller

Claims (16)

An antenna unit composed of a plurality of antenna elements;
A signal branching device that splits signals received by a plurality of antenna elements into one signal set, and branches a path of the signal sets received by the plurality of antenna elements into m sets;
M phase shifters that respectively change the phase of the signal branched by the signal branching unit based on phase change amount data;
A power distributor / combiner that combines m signals output from the phase shifter into one signal;
An antenna system, wherein a signal output from the power distributor / combiner is formed into an antenna directivity pattern corresponding to a communication destination. The antenna system according to claim 1, wherein
The signal splitter is
An antenna system comprising a directional coupler. The antenna system according to claim 1, wherein
The signal splitter is
An antenna system comprising a duplexer. The antenna system according to claim 1, wherein
The antenna branching system is configured by combining at least two of a directional coupler, a duplexer, and a switch. A relay station that receives a signal transmitted by a base station, generates a new signal based on the signal, and transmits the generated signal to a communication destination terminal,
The relay station has an antenna system;
The antenna system is
An antenna unit composed of a plurality of antenna elements;
A signal branching device that splits signals received by a plurality of antenna elements into one signal set, and branches a path of the signal sets received by the plurality of antenna elements into m sets;
M phase shifters that respectively change the phase of the signal branched by the signal branching unit based on phase change amount data;
A power distributor / combiner that combines m signals output from the phase shifter into one signal;
The said antenna system forms the signal output from the said electric power divider / combiner in the shape of the antenna directivity pattern corresponding to a communication destination, The relay station characterized by the above-mentioned. The relay station according to claim 5,
The signal splitter is
A relay station comprising a directional coupler. The relay station according to claim 5,
The signal splitter is
A relay station comprising a duplexer. The relay station according to claim 5,
The signal branching unit is configured by combining at least two of a directional coupler, a duplexer, and a switch. The relay station according to claim 5,
A control device for controlling the operation of the antenna system;
The controller is
A signal processing unit for restoring a received signal and generating a transmission signal;
A synchronization unit that performs synchronization processing of the antenna system;
A relay station, comprising: a control unit that performs switching control of transmission operation / reception operation of the signal processing unit and switching control of the signal branching unit. The relay station according to claim 9, wherein
The signal splitter is
A relay station comprising a switch that switches connection between the signal of the antenna unit and the m phase shifters based on a control signal output from the control unit. A base station that is a signal transmission / reception source, and a relay station that receives the signal transmitted by the base station, generates a new signal based on the signal, and transmits the generated signal to a communication destination terminal. A wireless communication system comprising:
The relay station has an antenna system;
The antenna system includes an antenna unit composed of a plurality of antenna elements,
A signal branching device that splits signals received by a plurality of antenna elements into one signal set, and branches a path of the signal sets received by the plurality of antenna elements into m sets;
M phase shifters that respectively change the phase of the signal branched by the signal branching unit based on phase change amount data;
A power distributor / combiner that combines m signals output from the phase shifter into one signal;
The said antenna system forms the signal output from the said electric power divider / combiner in the shape of the antenna directivity pattern corresponding to a communication destination, The radio | wireless communications system characterized by the above-mentioned. The wireless communication system according to claim 11, wherein
The signal splitter is
A wireless communication system comprising a directional coupler. The wireless communication system according to claim 11, wherein
The signal splitter is
A radio communication system comprising a duplexer. The wireless communication system according to claim 11, wherein
The signal branching unit has a configuration in which at least two of a directional coupler, a duplexer, and a switch are combined. The wireless communication system according to claim 11, wherein
A control device for controlling the operation of the antenna system;
The controller is
A signal processing unit for restoring a received signal and generating a transmission signal;
A synchronization unit that performs synchronization processing of the antenna system;
A wireless communication system, comprising: a control unit that performs switching control of transmission operation / reception operation of the signal processing unit and switching control of the signal branching unit. The wireless communication system according to claim 15,
The signal splitter is
A wireless communication system comprising a switch that switches connection between the signal of the antenna unit and the m phase shifters based on a control signal output from the control unit.

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