JP6586049B2 - Antenna adjustment method and communication system - Google Patents

Description

  The present invention relates to an antenna adjustment method and a communication system.

  In wireless communication, it is expected that communication capacity can be increased by performing multiplexing in addition to the same frequency and polarization using OAM (Orbital Angular Momentum) waves (for example, Non-Patent Document 1). 2). An OAM wave is a radio wave having orbital momentum. This radio wave has the same phase spirally with respect to the traveling direction. The OAM mode differs depending on the number of phase rotations in this spiral shape. The OAM mode L1 makes one rotation, whereas the OAM mode L2 makes two rotations. Similarly, in the OAM mode L3, the number of revolutions is three times. Separate radio signals can be communicated to each of the plurality of OAM modes. Furthermore, OAM waves having such characteristics can be multiplexed in combination with V (vertical) / H (horizontal) polarization, frequency channels, and the like.

  In order to use the OAM wave for wireless communication, the radio wave may be transmitted through a parabolic antenna having a cut or a dielectric provided with a step. Alternatively, OAM waves may be transmitted and received by arranging a plurality of patch antennas on the circumference and setting a predetermined phase for each antenna element.

Fabio Spinello, Elettra Mari, Matteo Oldoni, Roberto A. Ravanelli, Carlo G. Someda, Fabrizio Tamburini, Filippo Romanato, Piero Coassini, Giuseppe Parisi, “Experimental near field OAM-based communication with circular patch array”, [online], 2015 July 24, [Search May 25, 2016], <URL: http://arxiv.org/abs/1507.06889> Zhang Y, Feng W and Ge N, “On the Restriction of Utilizing Orbital Angular Momentum in Radio Communications”, Proc. VIII International Conference on Communications and Networking in China (CHINACOM), [online], April 20, 2013, p. .271-275, [Search June 8, 2016], <URL: https://www.computer.org/csdl/proceedings/chinacom/2013/9999/00/06694604.pdf>

  In order to realize wireless communication using an OAM wave whose phase changes spirally in the transmission direction, it is necessary to accurately adjust the direction of the transmission / reception axis (transmission / reception direction) between transmission and reception. Even if there is a slight misalignment, there is a difference in the helical phase change between the communication device on the transmission side and the communication device on the reception side. Due to the influence of this axial shift, it may be difficult to distinguish multiple OAM waves (for example, OAM modes L1 and L2).

  In view of the above circumstances, an object of the present invention is to provide an antenna adjustment method and a communication system that can adjust the transmission / reception direction of an OAM wave.

  One aspect of the present invention is an antenna adjustment method in a communication system having a first communication device and a second communication device, wherein the first antenna of the first communication device transmits an OAM (Orbital Angular Momentum) wave. A transmitting step, a receiving step in which the second antenna of the second communication device receives the OAM wave, and a control unit of the second communication device received in each of the plurality of antenna elements of the second antenna Based on the phase of the OAM wave, an angle of deviation in the radio wave radiation direction from the first antenna is obtained, and based on the obtained angle, adjustment of the vertical direction of the first antenna and the first antenna And a control step for individually adjusting the horizontal direction.

  One aspect of the present invention is the antenna adjustment method described above, wherein, in the control step, the phase of the OAM wave received by each of the plurality of antenna elements included in the second antenna, Based on the characteristics of the phase change when each of the plurality of antenna elements of the second antenna receives a signal transmitted from the first antenna when there is a deviation in the radio wave radiation direction, from the first antenna The angle of the vertical or horizontal deviation of the radio wave radiation direction is obtained.

  One aspect of the present invention is the antenna adjustment method described above, in which the control unit receives a horizontal or vertical direction based on the phase of the OAM wave received by each of the plurality of antenna elements of the second antenna. A determination step for determining whether or not adjustment of the first antenna is necessary, and in the control step, the vertical rotation adjustment of the first antenna is determined when the determination step determines that the vertical adjustment is necessary. The horizontal rotation of the first antenna is adjusted when the determination step determines that horizontal adjustment is necessary.

  One aspect of the present invention is the antenna adjustment method described above, wherein the control unit is configured to control the first antenna based on the phase of the OAM wave received at each of the plurality of antenna elements included in the second antenna. The method further includes a determination step of determining whether or not there is a phase change in the other direction before and after rotating one of the horizontal direction and the vertical direction, and in the control step, the horizontal phase is determined by the determination step. When it is determined that there is a change, the vertical rotation of the first antenna is adjusted, and when the determination step determines that there is a vertical phase change, the horizontal rotation of the first antenna is adjusted. Make adjustments.

  One aspect of the present invention is the antenna adjustment method described above, wherein, in the control step, the movable unit of the first communication device determines the orientation of the first antenna in the horizontal direction based on the obtained angle. Or rotate vertically.

  One aspect of the present invention is the antenna adjustment method described above, wherein the first communication device includes a three-dimensional array in which a plurality of antenna elements are arranged in three dimensions, and the first antenna is the three-dimensional The antenna element selected from the antenna elements included in the array, and in the control step, the selection unit of the first communication device has the antenna element included in the three-dimensional array based on the obtained angle. To select an antenna element to be used as the first antenna.

  One aspect of the present invention is a communication system having a first communication device and a second communication device, wherein the first communication device includes a first antenna that transmits an OAM (Orbital Angular Momentum) wave, The two communication devices are configured to detect the direction of radio wave radiation from the first antenna based on the phase of the OAM wave received at each of a second antenna that receives the OAM wave and a plurality of antenna elements of the second antenna. A controller that obtains an angle of deviation and individually adjusts the vertical direction of the first antenna and the horizontal direction of the first antenna based on the obtained angle;

  One aspect of the present invention is the communication system described above, in which the control unit receives the phase of the OAM wave received by each of the plurality of antenna elements included in the second antenna, and radio wave radiation from the first antenna. Based on the characteristics of the phase change when the antenna element receives a signal transmitted from the first antenna when there is a deviation in direction, the vertical direction or horizontal direction of the radio wave radiation direction from the first antenna Find the angle of deviation.

  According to the present invention, the transmission / reception direction of the OAM wave can be adjusted.

1 is a configuration diagram of a communication system according to a first embodiment of the present invention. It is a figure which shows the characteristic and generation | occurrence | production of the OAM wave of mode L1. It is a figure which shows the characteristic and production | generation of an OAM wave of mode L2. It is a figure which shows the characteristic and production | generation of an OAM wave of mode L-1. It is a figure which shows the state which the transmission side rotated Z-axis. It is a figure which shows the influence of the axis shift by Z-axis rotation shown in FIG. It is a figure which shows the state of the axis shift in case mode L1 is mistaken for L2. It is a figure which shows a phase change when the axial shift by the Z-axis rotation of the transmitting side array antenna translates on the receiving side plane. It is a figure which shows the structural example of the movable part by 1st Embodiment. It is a figure which shows the other structural example of the movable part by the embodiment. It is a figure explaining biaxial rotation of the array antenna by the subarray selection from the three-dimensional array by the same embodiment. It is a figure which shows an antenna element space | interval when selecting an array from the three-dimensional array by the same embodiment. It is a figure which shows an antenna element space | interval when selecting an array from the three-dimensional array by the same embodiment. It is a figure which shows an antenna element space | interval when selecting an array from the three-dimensional array by the same embodiment. It is a figure which shows an antenna element space | interval when selecting an array from the three-dimensional array by the same embodiment. It is a figure which shows Z-axis rotation in the transmission side by 2nd Embodiment. It is a figure which shows the X-axis rotation in the transmission side by the same embodiment. It is a figure which shows the operation | movement flow of the direction adjustment by shaft rotation in the communication system by the embodiment. It is a figure which shows the phase in each antenna position when there exists transmission rotation shift by the same embodiment. It is a phase characteristic graph which shows the characteristic of the phase change in each receiving antenna position in case there exists transmission rotation gap by the embodiment. It is a figure which shows the system for calculating | requiring the characteristic of the phase change which the phase characteristic graph of FIG. 20 shows. It is a figure which shows the operation | movement subflow in the communication system by the embodiment. It is a phase characteristic graph which shows the characteristic of the phase change in each receiving antenna position in case there exists a transmission rotation axial shift by the embodiment. It is a figure which shows the operation | movement subflow in the communication system by the embodiment. It is a figure which shows the other operation | movement flow of direction adjustment by the shaft rotation in the communication system by the embodiment. It is a figure which shows the receiving position on the receiving side by the embodiment. It is a figure which shows the graph of the phase change of the receiving side when the transmission side rotates by Z axis | shaft by the embodiment. It is a figure which shows the movement of the position of the antenna element on the X-axis using the Y-axis rotation by the embodiment. It is a figure which shows the condition which adjusts direction shift in order in the transmission side and receiving side by 3rd Embodiment. It is a figure which shows the operation | movement flow of the direction shift adjustment of both transmission and reception in the communication system by the embodiment. It is a block diagram of the communication system by 4th Embodiment. It is another block diagram of the communication system by the embodiment. It is a figure which shows the table | surface of the kind of the electromagnetic wave used for communication, the method used for axis adjustment, and the combination of the component part shared. It is a block diagram of the communication system by 5th Embodiment. It is a figure which shows the operation | movement flow of the communication system in switching of the other radio signal and OAM test signal by the embodiment. It is a figure which shows an operation | movement flow.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 is a configuration diagram of a communication system 1 according to a first embodiment of the present invention. In the figure, a configuration related to the direction adjustment of the OAM (Orbital Angular Momentum) wave transmitting / receiving array antenna is extracted and shown. The communication system 1 shown in the figure includes a communication device 10 and a communication device 20. Hereinafter, the communication device 10 or the communication device 20 that transmits the OAM wave is also referred to as “transmission side”, and the communication device 10 or the communication device 20 that receives the OAM wave is also referred to as “reception side”. Hereinafter, a case where the transmission side is the communication device 10 and the reception side is the communication device 20 will be described as an example. In the following description, the radiation direction of radio waves from the transmission side is the Y axis, the horizontal direction orthogonal to the Y axis is the X axis, and the vertical direction is the Z axis.

  The communication device 10 includes a signal generation unit 11, a phase adjustment unit 12, an array antenna 13, an axis deviation estimation / control unit 15, a movable unit 16, and a control radio unit 17. For example, the communication device 10 is realized by adding an axis deviation estimation / control unit 15, a movable unit 16, and a control radio unit 17 to an existing communication device including the signal generation unit 11, the phase adjustment unit 12, and the array antenna 13. can do. On the other hand, the communication device 20 includes an array antenna 21, a phase adjustment unit 23, a signal demodulation unit 24, a phase measurement unit 25, an axis deviation estimation / control unit 26, a movable unit 27, and a control radio unit 28. For example, the communication device 20 includes a phase measurement unit 25, an axis deviation estimation / control unit 26, a movable unit 27, and a control radio unit 28 in addition to an existing communication device including an array antenna 21, a phase adjustment unit 23, and a signal demodulation unit 24. It can be realized by adding.

  Functional units shared by each device in transmission / reception are the phase adjustment unit 12, the array antenna 13, the axis deviation estimation / control unit 15, the movable unit 16, and the control radio unit 17 in the communication device 10, and the array antenna 21 in the communication device 20. , Phase adjustment unit 23, axis deviation estimation / control unit 26, movable unit 27, and control radio unit 28. That is, when the communication device 10 is the reception side, each of the phase adjustment unit 12, the array antenna 13, the axis deviation estimation / control unit 15, the movable unit 16, and the control wireless unit 17 is connected to the reception side communication device 20. Operations similar to those of the phase adjustment unit 23, the array antenna 21, the axis deviation estimation / control unit 26, the movable unit 27, and the control radio unit 28 are performed. When the communication device 20 is on the transmission side, the phase adjustment unit 23, the array antenna 21, the axis deviation estimation / control unit 26, the movable unit 27, and the control radio unit 28 are each configured to adjust the phase of the communication device 10 on the transmission side. Operations similar to those of the unit 12, the array antenna 13, the axis deviation estimation / control unit 15, the movable unit 16, and the control radio unit 17 are performed. In the figure, the communication device 10 omits the description of the signal demodulator 24 and the phase measurement unit 25 required for reception, and the communication device 20 includes the signal generator 11 required for transmission. Is omitted. The configurations of the communication device 10 on the communication side and the communication device 20 on the reception side will be described below.

<Configuration on the sending side>
The signal generator 11 has a function of generating a transmission signal used for wireless communication, and also modulates the transmission signal if necessary. The phase adjustment unit 12 adds a predetermined phase that differs depending on each antenna element 14 of the array antenna 13 to the transmission signal generated by the signal generation unit 11. The array antenna 13 is an array antenna for transmission, and has a plurality of antenna elements 14. In the figure, an example is shown in which the array antenna 13 is an eight-element array antenna and includes eight antenna elements 14. Each phase of the input signal to each antenna element 14 is adjusted by the phase adjustment unit 12. The array antenna 13 transmits these phase-adjusted transmission signals as OAM waves.

  The axis deviation estimation / control unit 15 controls the movable unit 16 to change the transmission direction of the array antenna 13 based on the information regarding the axis deviation notified from the reception side. The axis deviation is a deviation (difference) between the transmission axis and the reception axis. The transmission axis is the direction in which the transmission side transmits signals, and the reception axis is the direction in which the reception side receives signals. Further, when the own apparatus is the reception side, the axis deviation estimation / control unit 15 estimates the axis deviation due to the rotation of the array antenna on the transmission side based on information such as the phase obtained from the received signal. The axis deviation estimation / control unit 15 instructs the control radio unit 17 to communicate related information in order to instruct the information on the axis deviation estimated on the reception side to rotate the array antenna on the transmission side.

  The movable part 16 has a mechanism for changing the transmission direction of the transmitting array antenna 13 by biaxial rotation. At this time, the movable unit 16 performs two-axis rotation of the Z-axis rotation and the X-axis rotation with respect to the array antenna 13 to change the transmission direction of the antenna.

  The control radio unit 17 performs communication between the communication device 10 and the communication device 20 by control radio. The control radio is a radio different from the OAM wave communication. The control radio unit 17 performs control communication with the communication device 20 by this control radio. The control radio unit 17 transmits and receives information on the adjustment of the axis shift obtained by the receiving-side communication device 20. Using this control radio, transmission side rotation adjustment start / completion, transmission side rotation axis and rotation adjustment amount are notified / confirmed between transmission and reception. In addition, as necessary communication according to the embodiment, for example, exchange control of transmission / reception, start / completion of coarse adjustment by electric field strength of received signal and fine adjustment by phase of OAM wave are notified / confirmed between transmission and reception by control radio .

  Although FIG. 1 shows a case where control communication is performed by wireless communication, wired communication may be performed as long as the communication device 10 and the communication device 20 can exchange related information. In this case, the communication device 10 includes a “control communication unit” that communicates with the communication device 20 by wire instead of the control wireless unit 17.

<Receiver configuration>
The array antenna 21 is a receiving array antenna and includes a plurality of antenna elements 22. The array antenna 21 receives the OAM wave transmitted from the transmitting array antenna 13. In the figure, an example is shown in which the array antenna 21 is an array antenna having the same eight elements as the array antenna 13 for transmission. However, the number of elements of the receiving array antenna 21 is not necessarily the same as the number of elements of the transmitting array antenna 13. The reception signal received by the array antenna 21 by radio is passed to the phase adjustment unit 23.

  The phase adjustment unit 23 performs adjustment to add a phase to the signal received by each antenna element 22 corresponding to the transmission side. The phase adjustment unit 23 passes the phase-adjusted reception signal to the signal demodulation unit 24. When the number of elements of the array antenna 13 on the transmission side and the number of elements of the array antenna 21 on the reception side are different, the phase adjustment unit 23 corresponds to the antenna element 14 of the array antenna 13 on the transmission side and the phase adjustment. The phase of the received signal is adjusted in consideration of the number and arrangement of the antenna elements 22 included in the array antenna 21. The signal demodulator 24 receives the phase-adjusted reception signal, performs demodulation according to the modulation performed on the transmission side, and outputs communication information.

  The phase measuring unit 25 receives signals received by all the antenna elements 22 of the receiving array antenna 21 and measures the phases of these signals. The phase measurement unit 25 passes the measured phase information to the axis deviation estimation / control unit 26.

  The axis deviation estimation / control unit 26 estimates axis deviation due to rotation of the transmitting array antenna 13 based on the phase information passed from the phase measurement unit 25. The axis deviation estimation / control unit 26 communicates with the transmitting side via the control radio about the estimated axis deviation information, and instructs the movable unit 16 to be controlled.

  The movable unit 27 has a mechanism for rotating the array antenna 21 in two axes in accordance with an instruction from the axis deviation estimation / control unit 26 to correct the axis deviation.

  The control radio unit 28 transmits related information such as an instruction for rotating the transmission array antenna 13 in two axes based on the axis deviation estimated by the axis deviation estimation / control unit 26 to the communication device 10 on the transmission side. Communicate by control radio. Using this control radio, transmission side rotation adjustment start / completion, transmission side rotation axis and rotation adjustment amount are notified / confirmed between transmission and reception. Also, according to the embodiment, transmission / reception switching adjustment, coarse adjustment based on the electric field strength of the received signal, and start / completion of fine adjustment using the OAM wave are notified / confirmed between the transmission and reception by the control radio.

  Note that the communication device 20 may perform control communication between transmission and reception by wire, not necessarily wireless. In this case, the communication device 20 includes a control communication unit that communicates with the communication device 10 by wire instead of the control wireless unit 28.

  2 to 4 are diagrams showing characteristics and generation of OAM waves. An OAM wave is a radio wave whose phase changes spirally. 2 to 4, the communication device 10 on the transmission side transmits an OAM wave using the array antenna 13 for transmission, and the communication device 20 on the reception side transmits the transmitted OAM wave to the array for transmission. Reception is performed using an array antenna 21 for reception similar to the antenna 13. A phase is set for each input signal to each antenna element 14 of the array antenna 13. The mode L of the OAM wave can be changed by setting the phase.

  FIG. 2 shows the characteristics and generation of the OAM wave in mode L1. In mode L1, the phase for each antenna element 14 is set such that all antenna elements 14 of array antenna 13 make one round and the phase is 2π (that is, 360 [°]). For example, as shown in the figure, in the case where one circuit has eight elements, the phase change between the adjacent antenna elements 14 is π / 4 (45 [°]).

  FIG. 3 shows the characteristics and generation of the OAM wave in mode L2. In mode L2, the phase for each antenna element 14 is set so that all antenna elements 14 of array antenna 13 make one round and the phase is 4π (that is, 720 [°]). In the case where one circuit is composed of 8 elements, the phase between adjacent antenna elements 14 is π / 2 (90 [°]). In mode L2, the rotation is twice that of the spiral in mode L1.

  FIG. 4 shows the characteristics and generation of an OAM wave in mode L-1. In mode L-1, the phase for each antenna element 14 is set so that all antenna elements 14 of array antenna 13 make one round and the phase is -2π (-360 [°]). In the case where one circuit has eight elements, the phase between adjacent antenna elements 14 is −π / 4 (−45 [°]). This mode L-1 becomes a reverse spiral with respect to the spiral rotation in the mode L1.

  Further, in the case of the modes L3, L4, L5,..., The phase set in one round by all the antenna elements 14 of the array antenna 13 is 6π, 8π, 10π, ... (1080 [°], 1440 [°], 1800 [ °], ...). As in the case described above, in the case where one circuit has eight elements, in the modes L3, L4, L5,..., The phase between adjacent antenna elements 14 is 3π / 4, π, 5π / 4,. ], 180 [°], 225 [°],. In the case of modes L-2, L-3, L-4,..., The phase set in one turn by all the antenna elements 14 of the array antenna 13 is −4π, −6π, −8π,. [°], −1080 [°], −1440 [°],. As in the above case, when the circumference is 8 elements, the phase between adjacent antenna elements 14 is −π / 2, −3π / 4 in modes L-2, L-3, L-4,. , -Π, ... (-90 [°], -135 [°], -180 [°], ...).

  The signal received by the antenna element 22 of the reception-side array antenna 21 is subjected to phase adjustment by the phase adjustment unit 23 in accordance with the above-described OAM mode, that is, phase adjustment corresponding to the transmission-side antenna element 14.

  As shown in FIGS. 2 to 4, when the array antenna 13 on the transmission side and the array antenna 21 on the reception side are 8 elements, the adjustment phase on the reception side is 0 [°] on the transmission side in mode L1. 45 [°], 90 [°],... 315 [°], 315 [°], 270 [°], 225 [°],. In the case of mode L2, the adjustment phase on the reception side corresponds to the adjustment phases 0 [°], 90 [°], 180 [°],..., 630 [°] on the transmission side, 630 [°], 540 [°], 450 [°],..., 0 [°]. Further, in the mode L-1, the adjustment phase on the reception side is the adjustment phase 0 [°], 315 [°] (−45 [°]), 270 [°] (−90 [°]) on the transmission side, ..., 45 [°] (-315 [°]), 45 [°] (-315 [°]), 90 [°] (-270 [°]), 135 [°] (-225 [ °]), ..., 0 [°].

Here, the influence of the axial displacement of the shaft rotation will be described with reference to FIGS. 5 and 6.
FIG. 5 is a diagram illustrating a state where the transmission side is rotated in the Z axis. FIG. 6 is a diagram showing the influence of the axis shift due to the Z-axis rotation shown in FIG. The following points can be understood from FIG.

(1) When the transmission side rotates, the transmission axis of the array antenna 13 on the transmission side (hereinafter referred to as the plane on the reception side) is parallel to the XZ plane where the array antenna 21 on the reception side is located (hereinafter referred to as the plane on the reception side). The point P at which the position (Y-axis direction) reaches is translated from the center position of the receiving-side array antenna 21.
(2) Since the transmission axis (Y-axis direction) of the array antenna 13 on the transmission side and the reception axis of the array antenna 21 on the reception side are different from each other, both the transmission and reception axes are in a mismatched state.

  Note that the calculation of the phase obtained on the receiving side based on the strict consideration due to the influence of the axial deviation with respect to the rotation of the array antenna 13 on the transmitting side will be described later in the second embodiment (FIGS. 19 to 21 and FIG. 23). By rotating the array antenna 13 on the transmission side, there is parallel movement of the axis, expansion of the distance between transmission and reception, and change in the reception direction on the reception side. The distance D between transmission and reception is sufficiently longer than the aperture diameter (radius ro) of the array antenna (D >> ro), and the angle α of rotation of the array antenna 13 on the transmission side is within a few degrees (α <5 °). ), Parallel movement mainly causes the phase to change on the receiving side. In the first embodiment, the fact that rotation on the transmission side changes the phase on the reception side will be roughly considered.

  With reference to FIG. 6, the influence of the translated axis shift will be described in the case where the receiving side is translated as shown in FIG. The eight antenna elements 22 included in the array antenna 21 are referred to as antenna elements a, b, c, d, e, f, g, and h, respectively. In FIG. 6, each phase assumed in the OAM mode L <b> 1 is centered on a point P where a transmission axis at a position parallel to the position of each antenna element a to h intersects the vertical plane on the receiving plane. Indicates placement. Also, the table shown at the bottom of the figure shows the antenna elements a to h on the receiving side and the antenna elements obtained from the phase arrangement of the OAM mode L1 when there is an axial deviation as shown in the upper diagram of FIG. The phases a to h are summarized. In the table shown in the lower side of FIG. 6, in the OAM mode L1, the original phase values of the antenna elements a to h when there is no axial deviation are shown in parentheses in the column of the antenna elements a to h. ing.

  As shown in the phase column of the table of the figure, it can be seen that the phase of each antenna element a to h is different from the original phase value when there is no axis deviation due to the influence of the axis deviation rotating on the transmission side. Moreover, when the table of FIG. 5 is examined in detail, even when the positive direction of the X-axis on the receiving side is assumed to be 0 [°] in the OAM mode L1, the phase of the antenna element a is 6 [°], and the antenna element b The phase is 18 [°], and the phase of the antenna element h is 354 [°]. That is, the phases of all the antenna elements are biased in the range of 0 to 30 [°] and 330 to 360 [°] in the axial misalignment state shown in FIG. Therefore, the reception in the OAM mode L1 (of course, in the other OAM modes L-1, L2,..., Etc.) cannot be received well.

A case where the OAM transmission modes L1 and L2 are misidentified will be described with reference to FIGS.
FIG. 7 is a diagram showing a state of axis misalignment when mode L1 is mistaken for mode L2. In the figure, the position of each antenna element on the receiving side and the phase arrangement of the OAM mode L1 centering on the point P where the transmission axis intersects the plane on the receiving side are shown. Compared to the example shown in FIG. 6, the amount of movement of the array antenna 21 on the receiving side in parallel on the plane on the receiving side is small due to the axial shift of the transmitting antenna rotating in the Z axis in FIG.

  Similar to FIG. 6, the table on the lower side of FIG. 7 shows the phases obtained by the antenna elements a to h when the axial deviation shown in the upper side of FIG. 7 occurs. The phase of the antenna element a is 55 [°], the phase of the antenna element b is 107 [°],..., And the phase of the antenna element h is 305 [°].

  Further, in this table, the phase value assumed to be obtained on the receiving side by transmission in the OAM mode L1 when there is no axis shift with each antenna element is shown in parentheses in the column of the antenna element. When there is no axial misalignment, the phase of the antenna element a is 22.5 [°], the phase of the antenna element b is 67.5 [°],..., And the phase of the antenna element h is 337.5 [°].

  Further, in this table, in the column of (L2), the phase value assumed to be obtained on the receiving side by transmission in the OAM mode L2 when there is no axis shift with each antenna element. In the OAM mode L2, the phase of the antenna element a is 45 [°], the phase of the antenna element b is 135 [°],..., And the phase of the antenna element h is 315 [°].

  In the table of FIG. 7, in the half of the antenna elements 22 surrounded by the broken line, the phase value when there is an axis shift is greater than the phase value assumed when transmitting in the OAM mode L1. It is close to the phase value assumed when transmitting with. Therefore, the OAM mode may be misidentified from the received signals obtained from these antenna elements. That is, the mode L1 is mistaken for the mode L2 in some elements of FIG.

  FIG. 8 is a diagram showing a phase change when the axial shift due to the Z-axis rotation of the array antenna 13 on the transmission side is approximated to the parallel movement on the plane on the reception side. FIG. 8 explains the influence of misidentifying the OAM mode other than the example of the eight elements described in FIG. 6 and FIG. 8, for an arbitrary number of antenna elements 22, the horizontal axis is the element position direction (0 to 360 [°]) around the point P shown in FIG. 7, and the vertical axis is the axis rotation on the transmitting side. The graph which shows the phase [°] changed by being influenced by the axis deviation due to. The value on the horizontal axis of the graph of FIG. 8 is equal to the original phase with no axis deviation in the OAM mode L1.

  Reference sign G1 indicates a phase [°] that has been changed by being affected by an axial shift caused by the shaft rotation. For reference, symbol G2 indicates the phase change of the OAM mode L1 when there is no axis shift, and symbol G3 indicates the phase change of the OAM mode L2 when there is no axis shift. The points plotted with solid lines on the respective lines G1, G2, and G3 indicate the phase values obtained by the respective antenna elements 22. As can be seen from the number of plotted points, the number of antenna elements in this example is ten. According to the figure, in six elements, which are more than half of the ten antenna elements within the range indicated by reference signs G4 and G5, the phase value is OAM more than the phase value of the original OAM mode L1 due to the axis misalignment. It can be seen that the value is close to the phase value of mode L2. In addition, the points plotted with dotted lines on the lines G1, G2, and G3 indicate the phases in the case of 8 elements.

  In the above description, the Z axis rotation misalignment has been described. However, the same problem occurs with respect to the X axis rotation misalignment. Hereinafter, a mechanism and an adjustment method necessary for adjusting the Z-axis rotation and the X-axis rotation on the transmission side, which are problems in wireless communication using OAM waves, will be described.

  FIG. 9 is a diagram illustrating a configuration example of the movable unit 16 that adjusts the positional deviation and the direction deviation. The movable part 16 in the configuration example shown in the figure has a function of rotating the array antenna 13 around two axes (X axis and Z axis). The Z axis is a vertical axis, the Y axis is a radio wave radiation direction, and the X axis is a horizontal axis perpendicular to the Z axis and the Y axis. In the figure, an array antenna 13 in which eight antenna elements 14 are arranged in a circle is taken as an example. The plate 31 of the array antenna 13 is connected to the back plate and the outer frame 33 by a plurality of back support portions 32. In the figure, the installation positions of the back support portions 32 are positions moved from the centers of the four sides on the left, right, top, and bottom of the plate 31 that supports the square array antenna 13 to the center.

  The shaft rotation of the movable part 16 shown in the figure is realized by extending and contracting a plurality of back support parts 32 as shown in the left balloon. Of the two left and right rear support portions 32 shown in the balloon, one of them is expanded and the other is contracted, whereby rotation about the Z axis (vertical axis rotation) is realized. The lower side in the balloon is a top view, and it can be seen that the plate 31 to which the array antenna 13 is attached is rotated about the Z axis (vertical axis rotation). With the rotation of the Z axis, the radio wave radiation direction changes from the Y axis to the left and right. In addition to the above-described vertical axis rotation, the rotation around the X axis (horizontal axis rotation) utilizes the expansion and contraction of the two back support portions 32 positioned above and below. By the expansion and contraction of the upper and lower back support portions 32, the rotation around the X axis (horizontal axis rotation) is realized in the same manner as the Z axis rotation by the left and right back support portions described above.

  Note that the position of the back support portion 32 is not necessarily near the center of each of the left, right, upper, and lower sides of the plate 31 that supports the square array antenna 13. For example, the four corners of the square may be the positions of the back support portion 32. In this case, the expansion and contraction of the back support part 32 for the X-axis rotation and the Z-axis rotation means that the installation position of the back support part 32 is shifted from the center of the four sides of the square plate 31 to the center as described above. It is a little different from the case. For example, in the Z-axis rotation, the two sets of back support portions 32 at the upper and lower corners of the right side are simultaneously expanded and contracted simultaneously, and the two back support portions 32 at the upper and lower corners of the left side are simultaneously reversed. Stretch.

  FIG. 10 is a diagram illustrating another configuration example of the movable unit 16 that adjusts the direction deviation. The movable part 16 having the configuration shown in the figure has a function of rotating around two axes, as in the case of FIG. Also in this figure, the array antenna 13 in which the eight antenna elements 14 are arranged in a circle is attached to the mounting plate 40. In FIG. 9, similarly to FIG. 9, the Z-axis is a vertical axis, the Y-axis is a radio wave radiation direction, and the X-axis is a horizontal axis perpendicular to the Z-axis and the Y-axis. In order to perform rotation about the X axis (horizontal axis rotation), the left and right arms 44 supporting the mounting plate 40 of the array antenna 13 are provided with rotating portions 45 and 46 that rotate the X axis, respectively. . As indicated by the curved arrows, the rotation units 45 and 46 rotate in the same direction before and after to achieve X-axis rotation.

  In addition, rotation about the Z axis (vertical axis rotation) includes a support 42 standing on the bottom plate 41, and a rotating unit 47 that can rotate all parts above the bottom plate 41 about the Z axis. It is realized by. The rotating unit 47 rotates in the Z axis as indicated by the curved arrow. An arm 44 that supports the mounting plate 40 of the array antenna 13 and extends to the left and right is attached to the column 42. Accordingly, since the arm 44 and the mounting plate 40 of the array antenna 13 also rotate on the Z axis, the array antenna can be rotated on two axes together with the rotation of the X axis described above.

  Furthermore, the movable part 16 having the configuration shown in FIG. 10 can be realized by adding a mechanism for rotating the Y-axis. The arm 44 that extends to the left and right is connected to the column 42 by a rotating unit 48 that rotates the array antenna 13 about the Y-axis as indicated by the dashed arrows. By rotating the rotating unit 48 in the Y axis, the position of the antenna element 14 can be changed, which can be used for adjusting the direction of the array antenna shown in FIG. 26 of the second embodiment described later.

  FIG. 11 is a diagram for explaining biaxial rotation of the array antenna 13 by selecting a sub-array from a three-dimensional array. In the figure, a sub-array corresponding to the direction is selected from a three-dimensional array 131 in which a large number of antenna elements 132 are arranged. FIG. 11A shows the three-dimensional array 131. The three-dimensional array 131 is a large-scale array in which many antenna elements 132 are three-dimensionally arranged in a rectangular parallelepiped region. FIG. 11B is a top view of the three-dimensional array 131 having the same arrangement of the antenna elements 132 as FIG.

  In FIG. 11A and FIG. 11B, two planar sub-arrays SA1 and SA2 are selected in the rectangular parallelepiped region of the three-dimensional array 131. Subarrays SA1 and SA2 indicate two planar subarrays selected as the subarray range. In the figure, the antenna elements 132 used in the subarrays SA1 and SA2 are eight elements arranged in a circle within the subarray range. The antenna elements 132 used in the subarrays SA1 and SA2 are indicated by shading.

  According to the drawing of these two selected subarrays SA1 and SA2 as seen from above, shown in FIG. 11B, the transmission axes of the subarrays SA1 and SA2 are different. If the transmission axis of the subarray SA1 before rotation is B1, the transmission axis of the subarray SA2 in the rotation embodiment is B2. As shown in FIG. 11, a subarray in which a plurality of antenna elements are appropriately selected from a large number of antenna elements 132 arranged three-dimensionally in a three-dimensional array 131, and another antenna element 132 is selected again from this subarray. With this subarray, an operation for rotating the transmission shaft can be realized.

  11 is adopted, the communication apparatus 10 shown in FIG. 1 includes a “subarray selection function unit” that selects a subarray from the three-dimensional array 131 instead of the movable unit 16. . In the selection of the sub-array from the three-dimensional array 131, there may be a situation where a number of antenna elements 132 that are not selected are arranged before and after the direction of radiating radio waves. A supplementary explanation will be given as to how the coupling effect affects these antenna elements.

  The antenna element intervals when different arrays are selected from the three-dimensional array are compared using FIGS. In FIGS. 12-15, the arrays selected from the three-dimensional arrays are different. FIG. 12 shows the selection of the front direction with a small antenna element spacing, FIG. 13 shows the selection of the diagonal direction with a small antenna element spacing, FIG. 14 shows the selection of the front direction with a large antenna element spacing, and FIG. Indicates diagonal selection.

  12 (a), 13 (a), 14 (a), and 15 (a) show the position of the array selected from the three-dimensional array. The three-dimensional arrays shown in these figures have a configuration in which eight antenna elements are arranged on a circumference on a two-dimensional plane and four layers of the two-dimensional plane array are stacked. The antenna element constituting this three-dimensional array is a dipole antenna having an antenna length of λ / 4 (λ is a wavelength). In each two-dimensional planar array of four layers, the diameter of the circumference where the antenna elements are arranged is 4λ, and the element spacing between the layers is small in FIGS. 12 and 13 (shorter than the wavelength (element spacing <λ)). In FIG. 15, the interval is increased (approximately the same as the wavelength (element interval≈λ)). The antenna element 141 is an antenna element not included in the selected array, and the antenna element 142 is an antenna element included in the selected array. 12 (b), FIG. 13 (b), FIG. 14 (b), and FIG. 15 (b) show the selected arrays in FIG. 12 (a), FIG. 13 (a), and FIG. 14 (a), respectively. FIG. 15 shows the radiation pattern of the array at the array position of FIG.

  12A and 14A, from the three-dimensional array, eight antenna elements in one layer of the two-dimensional planar array, specifically, the third layer in the four-layer two-dimensional planar array. All eight elements on the two-dimensional plane are selected. In this case, as shown in FIGS. 12B and 14B, a main lobe having a high electric field strength in the front direction (Y-axis direction) is obtained. However, as indicated by the arrows, the OAM wave is divided into two in the radial direction.

  On the other hand, in FIG. 13A and FIG. 15A, an antenna element is selected from a two-dimensional planar array of a plurality of layers, and radio wave radiation is set in an oblique direction. In this case, in FIG. 13B, the main lobe is inclined in a desired direction as indicated by an arrow. Also in FIG. 15B, the main lobe can be changed to the desired direction of the arrow D1. However, a strong side lobe also occurs in the other direction indicated by the arrow D2.

  12 to 15 show simulations in which the antenna element interval is changed. In addition to this, for example, the position of the antenna element, that is, the position of the antenna element before and after the radiation direction is slightly changed, and the antenna element is changed in the front and rear direction. It is also conceivable not to overlap, that is, not to match the positions. From such simulation analysis, for example, by devising the spacing and arrangement of the antenna elements as shown in FIG. 13, an operation of rotating the transmission axis by selecting the antenna elements from the three-dimensional array can be realized.

  9 to 11 show an example of the mechanism of the movable portion 16 for adjusting the axial deviation, the mechanism of the movable portion 27 for adjusting the axial deviation on the receiving side is also shown in FIGS. It is the same. When the selection of the subarray shown in FIG. 11 is adopted, the communication device 20 shown in FIG. 1 includes a subarray selection function unit that selects a subarray from the three-dimensional array 131 instead of the movable unit 27.

  Up to this point, in the first embodiment, with regard to the direction adjustment of the array antenna that transmits and receives the OAM wave, the direction adjustment movable mechanism (FIGS. 9 and 10) or the realization of the direction adjustment by selecting the subarray (FIG. 11) has been shown. Thereafter, in the second and subsequent embodiments, the direction adjustment process will be described.

[Second Embodiment]
In the second embodiment, a method will be described in which the transmission side adjusts the reception direction by sequentially performing horizontal rotation and vertical rotation.

  The adjustment of the antenna direction by vertical / horizontal axis rotation on the transmission side will be described with reference to FIGS. In FIGS. 16 and 17, the case where both the transmitting side and the receiving side are provided with an array antenna in which eight elements are arranged in a circle is taken as an example. 16 and 17, the vertical direction is the Z axis, the horizontal horizontal direction is the X axis, and the transmission / reception direction is the Y axis.

  FIG. 16 is a diagram illustrating Z-axis rotation on the transmission side. When the transmitting-side array antenna 13 is rotated about the Z-axis (vertical axis rotation), the point on the receiving side where the transmitting axis intersects the plane including the receiving-side array antenna 21 is left and right (parallel to the X-axis). Move in the right direction). For example, the array antenna 13 on the transmission side is rotated about the Z axis by several degrees clockwise as viewed from above (from the plus side to the minus side of the Z axis) (rotation in the direction of arrow E1). By this rotation, the orientation of the array antenna 13 on the transmission side moves from the original position on the reception side (triple circle with the symbol F0) to the right side (triple circle with the symbol F1). Conversely, the array antenna 13 on the transmission side is rotated about the Z axis counterclockwise as viewed from above (rotation in the direction of arrow E2). The direction of the array antenna 13 on the transmission side moves from the original position on the reception side (triple circle with reference F0) to the left side (triple circle with reference F2).

FIG. 17 is a diagram illustrating X-axis rotation on the transmission side. When the transmitting-side array antenna 13 is rotated (horizontal axis rotation) about the X axis as a central axis, the point on the receiving side where the transmitting axis intersects the plane including the receiving-side array antenna 21 is up and down (parallel to the Z-axis). Move in the right direction). For example, the X-axis rotation (rotation in the direction of the arrow E3) counterclockwise as viewed from the left side to the right side (from the negative X-axis side to the positive side) causes the direction of the array antenna 13 on the transmission side to be received. It changes from the original position on the side (triple circle with reference F0) to the lower part (triple circle with reference F3). Conversely, when the array antenna 13 on the transmission side is rotated in the clockwise direction (rotation in the direction of the arrow E4) as viewed from the left, the direction of the array antenna 13 on the transmission side is the original position on the reception side (reference F0). From the triple circle) to the top (triple circle with the symbol F4).
By adjusting the Z-axis (vertical axis) and X-axis (horizontal axis) rotations in order, the direction of the array antenna 13 on the transmission side is aligned with the origin of the XZ plane on the reception side, that is, coincides with the Y-axis. Can be made.

  FIG. 18 is a diagram illustrating an operation flow of direction adjustment by shaft rotation in the communication system 1. In this operation flow, the transmission and reception directions are adjusted by rotating the vertical and horizontal axes (Z axis and X axis) of the array antenna 13 on the transmission side on the transmission side. Further, in this operation flow, adjustment is performed in stages by rotating the Z axis and the X axis. In this adjustment, whether or not the transmission axis is aligned with the original direction is determined using the characteristics of phase change which will be described in detail later.

  The operation flow shown in the figure consists of four stages. These four stages include “adjustment confirmation check”, “Z-axis rotation adjustment”, “X-axis rotation adjustment”, and “adjustment completion confirmation”.

  In the “necessity check for adjustment” stage, first, the transmission / reception side and the reception side perform notification and confirmation of “starting adjustment of Z-axis rotation on the transmission side” by control radio. For example, the receiving-side communication device 20 notifies the transmitting-side communication device 10 of “starting adjustment of Z-axis rotation on the transmitting side” by control radio, and the communication device 10 receives the control radio, “Z axis rotation adjustment start” is recognized. Note that the communication device 10 may notify the communication device 20.

  In the operation flow shown in the figure, in the “necessity check for adjustment” stage, the axis deviation estimation / control unit 26 of the communication device 20 on the receiving side moves to the “Z-axis rotation axis adjustment” stage. It is determined whether or not adjustment by shaft rotation is unnecessary (or whether or not adjustment has been completed) (step S105). If it is determined that adjustment of the Z-axis rotation is necessary (step S105: NO), the axis deviation estimation / control unit 26 proceeds to the next step S110. The receiving-side axis deviation estimation / control unit 26 determines whether or not confirmation has been made within the entire Z-axis rotation range (step S110).

  When the receiving-side axis deviation estimation / control unit 26 determines that the Z-axis rotation has not yet been confirmed for the entire range (step S110: NO), the communication system 1 is in the second stage. Proceeding to the “adjustment of Z-axis rotation” stage, adjustment is performed with Z-axis rotation (step S115). In the adjustment process in the Z-axis rotation in step S115, the Z-axis rotation angle of the communication device 10 on the transmission side is changed. Specifically, in the adjustment process of the Z-axis rotation in step S115, first, the axis deviation estimation / control unit 26 of the communication device 20 on the reception side receives the OAM received by each of the plurality of antenna elements 22 included in the array antenna 21. Based on the wave phase, the amount of adjustment of the Z-axis rotation instructed to the transmission side is calculated. The communication device 20 on the reception side instructs the transmission-side communication device 10 to notify “adjustment amount of transmission side Z-axis rotation” using the control radio. The transmission-side axis deviation estimation / control unit 15 controls the movable unit 16 and changes the Z-axis rotation angle of the array antenna 13 based on the “adjustment amount of transmission-side Z-axis rotation” received from the reception side. After the adjustment process with the Z-axis rotation in step S115, the communication system 1 returns to the first step S105, and repeats the determination and the adjustment with the Z-axis rotation (steps S105 to S115).

  If the axis deviation estimation / control unit 26 of the communication device 20 on the receiving side determines that the adjustment by the Z-axis rotation is not necessary (or finished) in Step S105 (Step S105: YES), the adjustment of the Z-axis rotation (Step S105). It is determined that step S115) has been completed. The communication system 1 shifts to an operation stage that combines the third stage “adjustment of X-axis rotation” and the final stage “confirmation of adjustment completion”. However, if the axis deviation estimation / control unit 26 of the communication device 20 on the receiving side determines that the Z-axis rotation has been confirmed within the entire range in step S110 (step S110: YES), the rotation adjustment incomplete is displayed. (Step S140), the operation flow process of FIG. 18 is terminated.

  When the process proceeds to the “adjustment of X-axis rotation” stage, the transmission / reception side and the reception side perform notification and confirmation of “start of transmission side X-axis rotation adjustment” by control radio. For example, the receiving-side communication device 20 notifies the transmitting-side communication device 10 of “starting adjustment of X-axis rotation on the transmitting side” by the control radio, and the communication device 10 receives the control radio and “Adjustment start of X-axis rotation” is recognized. Note that the communication device 10 may notify the communication device 20. The axis deviation estimation / control unit 26 of the receiving-side communication device 20 determines whether or not adjustment by X-axis rotation is unnecessary (or finished) (step S120). When it is determined that the adjustment by the X-axis rotation is necessary (step S120: NO), the axis deviation estimation / control unit 26 determines whether the X-axis rotation is confirmed within the entire range (step S125). .

  If the axis deviation estimation / control unit 26 on the receiving side determines that the confirmation of the X-axis rotation has not yet reached the entire range (step S125: NO), the adjustment on the X-axis rotation is performed (step S130). In the adjustment process by the X-axis rotation in step S130, the X-axis rotation angle of the communication device 10 on the transmission side is changed. In this X-axis rotation adjustment process, first, the axis deviation estimation / control unit 26 of the receiving-side communication device 20 is based on the phase of the OAM wave received by each of the plurality of antenna elements 22 included in the array antenna 21. The adjustment amount of the X-axis rotation instructed to the transmission side is calculated. The communication device 20 on the reception side uses the control radio to instruct the communication device 10 on the transmission side to notify the “adjustment amount of the transmission side X-axis rotation”. The transmission-side axis deviation estimation / control unit 15 controls the movable unit 16 and changes the X-axis rotation angle of the array antenna 13 based on the “adjustment amount of transmission-side X-axis rotation” received from the reception side. After the adjustment process by the X-axis rotation in Step S130, the communication system 1 returns to Step S120, and repeats the determination whether the adjustment by the X-axis rotation is unnecessary or not and the adjustment by the X-axis rotation (Step S120). -Step S130).

  When the axis deviation estimation / control unit 26 of the communication device 20 on the receiving side determines that the adjustment by the Z-axis rotation is unnecessary (or finished) in Step S120 (Step S120: YES), the communication system 1 completes the rotation adjustment. (Step S135). In step S135, using the control radio, the transmission / reception side and the reception side perform notification and confirmation of “transmission side rotation adjustment completion” by the control radio. For example, “control-side rotation adjustment completion” is notified from the reception-side communication device 20 to the transmission-side communication device 10 using control radio. The transmission-side communication device 10 receives this control radio and recognizes “transmission-side rotation adjustment completion”.

  If the axis deviation estimation / control unit 26 of the communication device 20 on the receiving side determines that the X-axis rotation of the entire range has been confirmed during the adjustment of the X-axis rotation (step S125: YES), the rotation adjustment is performed. Incomplete is displayed (step S140), and the operation flow of FIG. 18 is terminated. In the process of step S140, the control side is used to notify “transmission side rotation adjustment incomplete” from the reception side to the transmission side.

  Up to this point, the method of adjusting the direction of the array antenna 13 on the transmission side in stages by rotating the Z axis and the X axis has been described. Whether or not adjustment by each rotation is necessary is determined based on the characteristics of the phase change due to the rotation of the shaft. In the following, some examples of characteristics of phase change due to shaft rotation, which are used for determining whether adjustment is necessary, and detailed processing of adjustment using the characteristics will be described.

<Detailed processing example 1>
FIG. 19 is a diagram illustrating the phase at each antenna position when there is a transmission rotation shift. Here, the parameter conditions in the figure are defined. A distance between transmission and reception (between the communication device 10 and the communication device 20) is D [m]. Further, a circle where all the antenna elements 22 on the receiving side are arranged on the circumference is defined as C1. If the center of the circle C1 is the point Ro and the center of the circle where all the antenna elements 14 on the transmitting side are arranged is the point 0, the distance D is the distance between the point 0 and the point Ro. The position of the antenna element 22 on the reception side is determined by the central angle θ _o in the circle C1 and the angle β [°] of the spread from the transmission side of the antenna element 22 arranged on the circumference of the circle C1. That is, the radius of the circle C1 in which the antenna element 22 on the receiving side is arranged is obtained by D · tan β.

In the example of the array antenna 21 on the receiving side shown in the figure, eight antenna elements 22 are arranged in a circle. Antenna elements 22 having central angles θ _o = 22.5 [°], 67.5 [°], 112.5 [°],..., 337.5 [°] are respectively antenna elements a, b, c,. , H. Then, the transmitting-side array antenna 13 is rotated in the Z-axis direction by a deviation rotation angle (also referred to as an axis deviation rotation angle) α [°]. The phase value (phase change) due to this rotational deviation is defined as θ ₁ [°]. For OAM mode L1, with no rotational shift (original) phase, it will now be considered as the same as if the center angle theta _o for easy study. By applying this assumption in the same manner, the phase angle of the rotational deviation is set to θ _{1 as the} central angle at which the position of the antenna element 22 on the receiving side is seen around the axis having the axial deviation. As a result, the amount of phase change Δθ (= θ ₁ −θ _o ) due to the axis deviation is obtained.

In FIG. 19, the number of elements arranged in a circle is eight. However, for example, when the number of elements is ten, the central angles θ _o of the ten antenna elements 22 are 18 [°] and 54, respectively. [°], 90 [°],..., 342 [°]. For example, when the number of elements is 6, the center angles θ _o of the six antenna elements 22 are 30 [°], 90 [°], 150 [°],..., 330 [°].

Although here is a simple consideration on the premise when the OAM mode L1, if if the case of OAM mode L2, with no rotational deviation must have (original) phase considered 2 times the central angle theta _o There is. In another assumption, in the case of the OAM mode L3, the central angle θ _o is considered to be three times, or in another case of the OAM mode L−1, the central angle θ _{o is} −1 times, that is, plus or minus (± ) Consider that the sign is reversed.

20 and 23 are phase characteristic graphs showing the characteristics of the phase change at each receiving antenna position when there is a transmission rotation shift. Hereinafter, the phase characteristic graph illustrated in FIG. 20 is referred to as a phase characteristic graph (A), and the phase characteristic graph illustrated in FIG. 23 is referred to as a phase characteristic graph (B). 20 and FIG. 23 show a phase change when the shift rotation angle α is changed from −6 to 6 [°] as an example under the condition shown in FIG. Points plotted in the phase characteristic graph (A) shown in FIG. 20 represent phase changes when the rotation angle α = −6, −4, −2,..., 6 [°]. As for the position of the receiving antenna, the positions of the eight antenna elements a, b, c,..., H when the angle β = 8 [°] (center angle θ _o = 22.5 [°], 67 .5 [°], 112.5 [°],..., 337.5 [°]).

As shown in the phase characteristic graph (A) in FIG. 20, the center angle θ _o = 22.5 [°] of the circle C1 in which the antenna element 22 is arranged on the circumference in accordance with the change of the shift rotation angle α, 67. 5 [°], 112.5 [°],..., 337.5 [°] (corresponding to the position of each antenna element a, b, c,..., H), the phase change θ ₁ is different. I understand that. Further, when the shift rotation angle α is changed, the phase θ ₁ in each antenna element is changed as shown in the phase characteristic graph (A) of FIG. 20, and the phase θ is changed as shown in the phase characteristic graph (B) of FIG. The change amount Δθ (= θ ₁ −θ _o ) is the position of each of the antenna elements a, b, c,..., H (θ _o = 22.5 [°], 67.5 [°], 112.5 [°]. , ..., 337.5 [°]). If the phase of each antenna element 22 is known from the characteristics of these changes, the deviation rotation angle α can be specified.

  The characteristics of the phase change at each receiving antenna position when there is a transmission rotation axis shift shown in FIG. 20 can be obtained from the system shown in FIG.

FIG. 21 is a diagram showing a system for obtaining the characteristics of the phase change. FIG. 21A is a diagram in which the XZ plane on the reception side is the front, and FIG. 21B is an enlarged view of a part of FIG. In FIG. 21, the position of the antenna element 22 on the receiving side is defined as a point Rx. On the reception-side plane (XZ plane), there is a point Rx on the circumference of a circle C1 (circle of reception element arrangement) where the antenna element 22 is arranged. When the transmitting side rotates the Z axis at the rotation angle α, the transmission / reception direction changes. A circle C2 (phase calculation auxiliary circle) for obtaining a phase is assumed on a plane perpendicular to the transmission / reception direction. There is also a point Rx on the circumference of the auxiliary circle C2 for this phase calculation. Let P ₁ be the center of the auxiliary circle C2 for phase calculation.

Here, considering the length Zo of the vertical (Z-axis) component of the point Rx from the auxiliary circle C2 for phase calculation, Zo = r ₁ · sin θ ₁ is obtained. On the other hand, when the same length Zo is viewed from the circle C1 of the receiving element arrangement, Zo = ro · sin θ _o . Therefore, the following equation (1) is established.

Let T be the point where the point Rx is projected onto the X axis. The distance between the points P ₁ and T is r ₁ · cos θ _{1 when} considered from the auxiliary circle C 2 for phase calculation (triangle T (P ₁ ) (Rx) in a plane perpendicular to the transmission axis). The distance between the points P ₁ and T is Δx ₁ · cos α when viewed from the triangle T (P ₁ ) (R ₁ ) on the horizontal plane (XY plane). From the distance of point P ₁ and the point T, the following equation (2).

The center of the receiving element arrangement circle C1 is a point Ro. A straight line shifted in the X-axis direction by the rotation angle α with respect to the Y-axis from the point 0 that is the center of the circle where the antenna element 14 is disposed (transmission axis when the reception side rotates the Z-axis by the rotation angle α) is received. A point on the X axis that intersects the XZ plane on the side is defined as R1. At this time, the distance Δx between the point Ro and the point R ₁ is Δx = D · tan α from the distance D between the transmission surface and the reception surface (point 0 and point Ro) and the rotation angle α. Also, the distance [Delta] x is the relationship of Δx = Xo-Δx _1. Here we point Xo is horizontal point Rx (X-axis) is a component, strikes the ro · cos [theta] _o. From these relationships, the following equation (3) is obtained.

  Then, when this equation (3) is substituted into the above equation (2), the following equation (4) is obtained.

The above equations (1) and (4) are squared on both sides, and the sum of those sides is taken. Here, since the left side is gathered as r ₁ ² · (sin ² θ ₁ + cos ² θ ₁ ) = r ₁ ² , the following equation (5) is obtained.

Further, by dividing both sides of the equation (4) by r ₁ and then substituting the square root of the equation (5) into the denominator r ₁ on the right side, the following equation (6) is obtained.

Therefore, the phase θ ₁ is given by the following equation (7).

  The phase characteristic shown in the phase characteristic graph (A) of FIG. 20 is calculated by the above equation (7) when the transmission side rotates on the Z axis at the rotation angle α.

  FIG. 22 is a diagram illustrating an operation subflow of the communication system 1 using the characteristics of the phase change indicated by the phase characteristic graph (A) of FIG. The operation subflow shown in FIG. 22 is whether or not the adjustment by the Z-axis rotation in step S105 is unnecessary in a part of the operation flow of the direction adjustment shown in FIG. 18 (step S105 to step S115). ) Determination processing and details of the adjustment (change of the Z-axis rotation angle) in the Z-axis rotation in step S115.

  First, the detailed process of the determination process whether or not the adjustment in step S105 is unnecessary (or finished) will be described. In step S105, the communication device 20 performs processing and determination in the following four stages.

  As a first step, first, the phase measurement unit 25 of the communication device 20 acquires a phase from each antenna element 22 (step S205). Since the receiving-side array antenna 21 assumed in FIG. 20 (or FIG. 23 described later) is in the form of eight elements, the phase measurement unit 25 uses the phase value of the radio signal received by each of these antenna elements 22. Get.

In the second stage, the axis deviation estimation / control unit 26 of the communication device 20 calculates the relative phases of all the antenna elements 22 (step S210). In the phase characteristic graph (A) used for comparison in the subsequent step S215, the phase value of reception by the OAM wave is assumed based on the phase θ _o at the position of the antenna element 22 in the array antenna 21 on the reception side. . That is, θ _o = 22.5 [°], 67.5 [°], 112.5 [°],..., 337.5 [°] means that the position of the antenna element 22 is on the plane of the XZ coordinate. And the X axis direction is 0 [°], and the positions are 22.5 [°], 67.5 [°], 112.5 [°], ..., 337.5 [°] counterclockwise. Therefore, the axis deviation estimation / control unit 26 adds an appropriate phase difference to the phases acquired for each antenna element 22 (all eight phases if there are eight elements). As such a phase difference, for example, for each antenna element 22, a difference between a value obtained by adding a certain phase difference to the acquired phase and a phase θ _o corresponding to the antenna element 22 is obtained, and these differences are obtained. What is necessary is just to obtain | require the phase difference which becomes the minimum of the square sum of. Specifically, for each antenna element 22 at a position of phase θ _o = 22.5 [°], 67.5 [°], 112.5 [°],..., 337.5 [°], the phase value − When 38.6 (321.4) [°], 5.8 [°], 51.9 [°],..., 278.2 [°] are obtained, the axis deviation estimation / control unit 26 determines the position. Add the phase difference of 60 [°]. By this addition, θ _o = 21.4 [°], 65.8 [°], 111.9 [°],..., 338.2 [°], which is close to the antenna element position θ _o . In this description, the case of the OAM mode L1 is described, but in the case of the OAM mode L2, L3,..., The phase 2θ _o , 3θ that is two times, three times, etc. with respect to the antenna element position θ _o . _The phase difference to be added is calculated assuming _o,. In the case of OAM mode L-1 determines the phase difference to be added by assuming the phase - [theta] _o obtained by inverting the plus or minus sign of the antenna position theta _o.

  In the third stage, the axis deviation estimation / control unit 26 compares the phase calculated in the previous step S210 with the phase characteristic graph (A) shown in FIG. 20 (step S215). The axis deviation estimation / control unit 26 collates the relative phases of all the antenna elements 22 calculated in step S210 with the phase characteristic graph (A). In the phase characteristic graph (A), the phase change is shown for a condition where the deviation rotation angle α is different from −6 to 6 [°]. However, in the comparison process in step S210, the axis deviation estimation / control unit 26 determines how much the phase calculated in step S210 matches the phase characteristic when there is no deviation (α = 0 [°]). Alternatively, it is checked whether the characteristics are close to the characteristics when the deviation is the smallest (α = ± 2 [°] in FIG. 20).

  In the fourth stage, the axis deviation estimation / control unit 26 determines whether or not the phase characteristics determined to be identical in step S215 coincide with the straight line graph when there is no deviation (Z-axis rotation adjustment unnecessary) (step S215). S220). That is, the axis deviation estimation / control unit 26 compares the phase characteristics graph (A) in step S215 with the phase of all the antenna elements 22 calculated in step S210 being free from deviation (α = 0 [°]). ) Is not necessary to adjust the Z-axis rotation, or similar to the other curve graph (α ≠ 0 [°]) when there is a deviation, Check if it is necessary.

  Alternatively, the axis deviation estimation / control unit 26 confirms here that, when comparing all phases with the phase characteristic graph (A), than the straight line graph when there is no deviation (α = 0 [°]), It is similar to the graph when the deviation is minimum (rotation angle α = ± 2 [°] in FIG. 20), and it is necessary to adjust the Z-axis rotation or when there is no deviation (α = 0 [°] It is also possible to determine whether or not the Z-axis rotation adjustment is necessary. In the phase characteristic graph (A) shown in FIG. 20, α = ± 2 [°] is the minimum deviation angle, but more detailed rotation angle α = ± 1 [°], or α = ± as necessary. A graph of 0.1 [°] may be obtained by calculation and prepared and set as a reference value for determining the necessity of rotation adjustment.

Next, the details of the adjustment process in the shaft rotation in step S115 will be described. In step S115, the axis deviation estimation / control unit 26 of the receiving-side communication device 20 performs the following two processes.
In the first process, the axis deviation estimation / control unit 26 determines which curve in the phase characteristic graph (A) shown in FIG. 20 is close to the relative phase of each antenna element 22 (step S305). The axis deviation estimation / control unit 26 determines whether or not the adjustment of the Z-axis rotation is unnecessary before the process of step S305 (step S105), and all the antenna elements 22 of the array antenna 21 on the reception side. The phase obtained by the phase measurement unit 25 was set as a relative value (step S210), and then compared with a straight line graph without deviation (α = 0 [°]) in the phase characteristic graph (A) (step S215). In step S305, the axis deviation estimation / control unit 26 determines the relative phase of each of the antenna elements 22 in the other phase characteristic graph (A) (in FIG. 20, α = ± 2 [°] with axis deviation). Compare with curve. Then, the axis deviation estimation / control unit 26 specifies a curve closest to the phases of the eight antenna elements 22.

  In the second process, the axis deviation estimation / control unit 26 rotates the array antenna 13 on the transmission side in the Z-axis direction in the opposite direction to the deviation rotation angle α, which is the parameter of the closest curve obtained (step). S310). In this Z-axis rotation operation, the transmitting-side array antenna 13 is rotated in the reverse direction by the shift angle α obtained from the phase obtained for the receiving-side array antenna 21 so that there is no axial shift. That is, the axis deviation estimation / control unit 26 of the communication device 20 instructs the array antenna 13 to rotate in the Z-axis direction by a rotation angle (−α) opposite to the deviation rotation angle α calculated in step S305. The control wireless unit 28 wirelessly transmits the generated control signal to the communication device 10. The control radio unit 17 of the communication apparatus 10 receives the control signal, and the axis deviation estimation / control unit 15 rotates the array antenna 13 in the Z-axis direction by a rotation angle (−α) based on the received control signal. The movable part 16 is controlled.

  In FIG. 22 (step S105 to step S115, step S205 to step S220, step S305 to step S310), only the adjustment process in the Z-axis rotation has been described. In addition to this, in the X-axis rotation corresponding to the second stage process (step S120 to step S130) in the operation flow shown in FIG. 18, the communication system 1 sets the X axis in step S105 to step S115 to the Z axis, and the Z axis to Instead of the X axis, processing is performed by the same operation subflow as in FIG.

<Detailed processing example 2>
The phase characteristic graph (B) shown in FIG. 23 represents the characteristics of the phase change at each receiving antenna position when there is a transmission rotation axis shift. The phase characteristic graph (B) is obtained under the same conditions as in FIG. That is, the deviation rotation angle α when the Z-axis is rotated on the transmission side is set to −6 to 6 [°]. There are eight antenna elements 22 on the receiving side, and the positions of the antenna elements 22 are arranged on the circumference of a circle C1 shown in FIG. The spread angle β of the antenna elements 22 from the transmission side is β = 8 [°], and the position of each antenna element 22 is the central angle θ _o = 22.5 [°] on the circumference of the circle C1, 67. The positions are 5 [°], 112.5 [°], ..., 337.5 [°].

On the other hand, the phase characteristic graph (B) shown in FIG. 23 differs from the phase characteristic graph (A) shown in FIG. 20 in that the horizontal axis indicates the shift rotation angle α and the vertical axis indicates the phase change amount Δθ (= θ ₁ − Take θ _o ) [°]. In this phase characteristic graph (B), how much the phase obtained in each antenna element 22 in the array antenna 21 on the reception side changes when the array antenna 13 on the transmission side is rotated at a rotation angle α [°]. Represents. In the phase characteristic graph (B) shown in FIG. 23, any antenna element 22 is based on the phase when there is no axis shift (α = 0 [°] which is the center in the graph).

  FIG. 24 is a diagram illustrating an operation subflow of the communication system 1 using the characteristics of the phase change indicated by the phase characteristic graph (B) of FIG. The operation subflow shown in FIG. 24 is whether or not the adjustment by the Z-axis rotation in step S105 is unnecessary in a part of the operation flow of the direction adjustment shown in FIG. 18 (step S105 to step S115). ) Determination processing and details of the adjustment (change of the Z-axis rotation angle) in the Z-axis rotation in step S115. The excerpt from FIG. 18 is the same processing as in FIG. 22, but the specific processing contents are different in the operation subflow shown in FIG.

  First, the detailed process of the determination process whether or not the adjustment in step S105 is unnecessary (or finished) will be described. In step S105, the communication device 20 acquires the phase of the receiving antenna (step S405), grasps the amount of phase change (step S410), compares it with the phase characteristic graph (B) (step S415), and determines whether or not there is a deviation (step S420). ) In order.

  In the reception antenna phase acquisition process (step S405), the communication device 20 rotates the array antenna 13 on the transmission side in the Z-axis and each of all the antenna elements 22 of the array antenna 21 on the reception side when the shift rotation angle α is different. To obtain two phase values. Here, it is assumed that the number of elements of the array antenna 21 on the receiving side is eight. The phase measurement unit 25 of the communication device 20 rotates the Z-axis by a predetermined angle difference (approximately Δα = ± 1 to 3 °) from the rotation angle α1 when the transmitting-side array antenna 13 is at the rotation angle α1. The phase value in each antenna element 22 at the time (when the rotation angle α2 = α1 + Δα) is acquired. That is, a total of 16 phase values obtained by all the antenna elements 22 on the receiving side are obtained (8 elements × 2 times: at the rotation angles α1 and α2).

  Specifically, the phase measurement unit 25 of the communication device 20 acquires the phase when each antenna element 22 receives an OAM wave transmitted from the communication device 10. Subsequently, the axis deviation estimation / control unit 26 of the communication device 20 transmits to the communication device 10 a control radio that instructs the Z-axis rotation by the rotation angle Δα. The axis deviation estimation / control unit 15 of the communication apparatus 10 controls the movable unit 16 so that the transmitting-side array antenna 13 rotates in the Z axis by the rotation angle Δα based on the control radio. If the rotation angle Δα is known on the transmission side and the reception side, the rotation angle Δα may not be set in the control radio. Alternatively, the transmitting-side array antenna 13 may be rotated about the Z-axis by the rotation angle Δα at a predetermined timing on the transmitting side without using the control radio. The phase measuring unit 25 of the communication device 20 acquires the phase of the OAM wave received from the communication device 10 by each antenna element 22 after the array antenna 13 on the transmission side rotates in the Z axis.

  In the process of grasping the amount of phase change (step S410), the receiving-side axis deviation estimating / controlling unit 26 acquires different rotation angles α by rotating the transmitting-side array antenna 13 in the immediately preceding step S405 by rotating the Z-axis. The difference between the two phase values for each antenna element 22 on the receiving side is calculated, and the phase change amount of each antenna element 22 is grasped. By obtaining the amount of phase change of each antenna element 22, the process of calculating an appropriate relative phase (step S 210) required in the previous FIG. 22 is replaced with simple difference calculation (simply measuring two phases). It is possible to replace the process with only a difference in values.

In the comparison process with the phase characteristic graph (B) (step S415), the receiving-side axis deviation estimation / control unit 26 shows the phase change amounts calculated for all the receiving-side antenna elements 22 as shown in FIG. Compare with the phase characteristic graph (B). In comparison with the phase characteristic graph (B), an angle Δα (= α1−α2) rotated when acquiring two phases is considered. For example, when Δα = 2 [°], the antenna element 22 (position θ _o on the circumference of the circle C1: 22.5 [°], 67.5 [°], 112.5 [°],... 337.5 [°]) are calculated to be −12.3 [°], −15.6 [°], −9.1 [°], ... 12.2 [°], respectively. To do. When these phase changes are obtained, in the phase characteristic graph (B) of FIG. 23, it is close to the time when the shift rotation angle changes from α = −4 [°] to −2 [°].

  In the determination process of whether or not there is a deviation (step S420), the receiving-side axis deviation estimation / control unit 26 determines that the current rotation angle is based on the result of comparison with the phase characteristic graph (B) in the immediately preceding step S415. It is determined whether or not it coincides with the rotation angle α = 0 [°] (whether adjustment of the Z-axis rotation is unnecessary). That is, for example, when the Z-axis rotation Δα = −3 [°], the phase change of the antenna element 22 is −7.2 [°], −17.7 [°], −22.9 [°],. When the angle is 1 [°], the Z-axis is rotated from α1 = 3 [°] to α2 = 0 [°]. Therefore, in such a case (α2 = 0 [°]), the rotation angle α = 0 [°] (= α2), and it can be determined that rotation adjustment is unnecessary. As can be seen from the phase characteristic graph (B) shown in FIG. 23, not only does the antenna direction exactly coincide with α = 0 [°], but it is also acceptable in response to necessity such as communication quality in wireless communication. The value α = ± 1 [°] or α = ± 0.1 [°] may be used.

  On the other hand, in the adjustment process with Z-axis rotation (step S115), the communication system 1 confirms the rotation angle α by comparing the phase change amount with the phase characteristic graph (B) (step S505), and the confirmed rotation angle. The transmitting side array is rotated in the Z axis direction opposite to α (step S510).

  The axis deviation estimation / control unit 26 of the communication device 20 compares the phase change amount with the phase characteristic graph (B), and calculates two phase differences (phase change amounts) at the different rotation angles α1 and α2. The phase characteristic graph (B) is compared and a close rotation angle α is confirmed (step S505). Specifically, in the above-described example, the axis deviation estimation / control unit 26 of the communication device 20 shows the phase obtained by all the antenna elements 22 on the reception side in the case of Δα = 2 [°] in FIG. Comparison is made with the phase characteristic graph (B) shown. The axis deviation estimation / control unit 26 specifies a graph having the closest phase difference obtained for each antenna element 22 as compared with the phase characteristic graph (B), and changes the rotation angle from α1 = −4 [°] to α2 =. Confirm that the phase is acquired by rotating the Z-axis to -2 [°].

  The communication device 20 rotates the transmission-side array in the direction opposite to the rotation angle α confirmed in step S505 (step S510). That is, it is assumed that the axis deviation estimation / control unit 26 of the communication device 20 acquires the phase rotated from the rotation angle α1 = −4 [°] to the rotation angle α2 = −2 [°] as described above. In this case, the axis deviation estimation / control unit 26 rotates the Z axis in the direction opposite to the rotation angle 2 [°], that is, the rotation angle α2 = −2 [°] from the current rotation angle α2 = −2 [°]. Then, the array antenna 13 on the transmission side is further rotated. That is, the axis deviation estimation / control unit 26 of the communication device 20 transmits a control radio that instructs to rotate the Z axis in the direction opposite to the rotation angle α2. The axis deviation estimation / control unit 15 of the communication apparatus 10 controls the movable unit 16 to rotate the array antenna 13 in the direction opposite to the rotation angle α2 based on the control radio. By this rotation, the rotation angle α = 0 [°], and it can be expected that the axis deviation of the Z-axis rotation is eliminated.

  Up to now, in the operation subflows of FIGS. 22 and 24, it has been described that the adjustment of the Z-axis rotation and the X-axis rotation in the operation flow of FIG. 18 is performed in order. However, the phase characteristic graph (A) (FIG. 20) and the phase characteristic graph (B) (FIG. 23) used for the description of the operation subflows of FIGS. 22 and 24 are based on the calculation analysis of only the Z-axis rotation. Here, a case where there is an axial shift of both Z-axis rotation and X-axis rotation will be described. When the phase characteristic graph (A) and the phase characteristic graph (B) are examined in detail, the phase of each antenna element 22 is several tens at the maximum due to axial misalignment of several degrees or less (≦ 6 [°]). It changes by about degrees (≈50 [°]). However, when the change amounts of the phases of all the antenna elements 22 are averaged, the change amounts cancel each other, and the average change amount becomes small. Using this property, the rotation adjustment of the axis shift performed based on the phase change obtained by the receiving-side antenna element 22 using the OAM wave is performed as in the fifth embodiment to be described later on the transmitting / receiving-side array antenna. Start from a state where the directions of are generally opposed. If the Z-axis rotation is adjusted in this state, the phase characteristic of each antenna element 22 on the receiving side is affected by the X-axis rotation axis shift in addition to the Z-axis rotation axis shift. The antenna element 22 can be dealt with by averaging the phase characteristics. Specifically, all the phase characteristics of each antenna element 22 may be dealt with by giving a certain range of numerical values by a certain amount (for example, about a dozen degrees). In other words, when adjusting the Z-axis rotation, the adjustment may be performed assuming that the phase amount for adjusting the X-axis rotation later is added.

  In FIG. 24 (step S105 to step S115, step S405 to step S420, step S505 to step S510), only the adjustment processing in the Z-axis rotation has been described. In addition to this, in the X-axis rotation corresponding to the second stage process (step S120 to step S130) in the operation flow shown in FIG. 18, the communication system 1 sets the X axis in step S105 to step S115 to the Z axis, and the Z axis to Instead of the X axis, processing is performed by the same operation subflow as in FIG.

<Example of other processing for adjusting the direction by rotating the shaft>
FIG. 25 is a diagram showing another operation flow of direction adjustment by shaft rotation in the communication system 1. 25 shows another method of adjusting the transmission / reception direction by rotating the vertical and horizontal axes (Z axis and X axis) on the transmission side. In this adjustment, the receiving side determines whether or not the direction of adjustment of the shaft rotation is in accordance with the presence or absence of a phase change due to the rotation of another shaft. That is, the receiving side uses the phase change of the X-axis rotation for determination in the Z-axis adjustment, and uses the phase change of the Z-axis rotation for determination in the X-axis adjustment.

  The operation flow shown in FIG. 25 is roughly composed of four stages, similar to the operation flow shown in FIG. These four stages include “adjustment necessity confirmation”, “Z-axis rotation adjustment”, “X-axis rotation adjustment”, and “adjustment completion confirmation”.

  In the “necessity check for adjustment” stage, first, the transmission side and the reception side perform notification and confirmation of “starting adjustment of Z-axis rotation on the transmission side” by control radio. For example, the receiving-side communication device 20 notifies the transmitting-side communication device 10 of “starting adjustment of Z-axis rotation on the transmitting side” by control radio, and the communication device 10 receives the control radio, “Z axis rotation adjustment start” is recognized. Note that the communication device 10 may notify the communication device 20.

  In the operation flow shown in the figure, at the “necessity check for adjustment” stage, the axis deviation estimation / control unit 26 of the communication device 20 on the receiving side moves to the “axis adjustment for Z-axis rotation” stage. It is determined whether or not there is a phase change due to shaft rotation (step S605). If it is determined that there is a phase change in the X-axis rotation (step S605: YES), the axis deviation estimation / control unit 26 proceeds to the next step S610. The receiving-side axis deviation estimation / control unit 26 determines whether or not confirmation has been made within the entire range of Z-axis rotation (step S610).

  If the receiving-side axis deviation estimation / control unit 26 determines that the Z-axis rotation has not yet been confirmed for the entire range (step S610: NO), the communication system 1 is in the second stage. Proceeding to the “adjustment of Z-axis rotation” stage, adjustment is performed with Z-axis rotation (step S615). In the adjustment processing with Z-axis rotation in step S615, the Z-axis rotation angle of the communication device 10 on the transmission side is changed. Specifically, in the adjustment of the Z-axis rotation in step S615, first, using the control radio, a notification instruction is given from the receiving-side communication device 20 to the transmitting-side communication device 10 of “the transmitting-side Z-axis rotation adjustment amount”. . The transmission-side axis deviation estimation / control unit 15 controls the movable unit 16 and changes the Z-axis rotation angle of the array antenna 13 based on the “adjustment amount of transmission-side Z-axis rotation” received from the reception side. After the adjustment (Z-axis rotation angle change) process in the Z-axis rotation in step S615, the communication system 1 returns to the first step S605, and repeats the determination and the adjustment in the Z-axis rotation (steps S605 to S615).

  After the end of the second stage, the communication system 1 shifts to an operation stage that combines “adjustment of X-axis rotation” in the third stage and “confirmation of completion of adjustment” in the last stage. When determining that there is no phase change in the X-axis rotation in step S605 (step S605: NO), the axis shift estimation / control unit 26 of the receiving-side communication device 20 determines that the adjustment of the Z-axis rotation has been completed. Then, the process proceeds to the subsequent “adjustment of X-axis rotation” stage. Note that if the axis deviation estimation / control unit 26 of the communication device 20 on the receiving side determines that confirmation has been made within the entire range of the Z-axis rotation during the adjustment of the Z-axis rotation (step S610: YES), the rotation adjustment is performed. Incomplete is displayed and the process ends (step S640).

  In the “adjustment of X-axis rotation” stage that has shifted, the axis deviation estimation / control unit 26 of the communication device 20 on the receiving side determines whether or not there is a phase change due to the Z-axis rotation (step S620). In this “adjustment of X-axis rotation” stage, prior to this determination, notification and confirmation of “transmission-side X-axis rotation adjustment start” are performed between transmission and reception using the control radio. For example, the receiving-side communication device 20 notifies the transmitting-side communication device 10 of “starting adjustment of X-axis rotation on the transmitting side” by the control radio, and the communication device 10 receives the control radio and “Adjustment start of X-axis rotation” is recognized. Note that the communication device 10 may notify the communication device 20. If the axis deviation estimation / control unit 26 of the communication device 20 on the receiving side determines that there is a phase change due to the Z-axis rotation (step S620: YES), whether or not it has been confirmed within the entire range of the X-axis rotation. Is determined (step S625).

  When determining that the X-axis rotation has not yet been confirmed for the entire range (step S625: NO), the receiving-side axis deviation estimation / control unit 26 performs adjustment with the X-axis rotation (step S630). In the adjustment process by the X-axis rotation in step S630, the X-axis rotation angle of the communication device 10 on the transmission side is changed. In this X-axis rotation adjustment process, first, the control side wireless communication device 20 instructs the transmission-side communication device 10 to notify the “transmission-side X-axis rotation adjustment amount”. The transmission-side axis deviation estimation / control unit 15 controls the movable unit 16 and changes the X-axis rotation angle of the array antenna 13 based on the “adjustment amount of transmission-side X-axis rotation” received from the reception side. After the adjustment process with the X-axis rotation in step S630, the communication system 1 returns to step S620, and repeats the determination as to whether or not there is a phase change in the Z-axis rotation and the adjustment with the X-axis rotation (step S620 to S620). Step S630).

  When the axis deviation estimation / control unit 26 of the communication device 20 on the receiving side determines that there is no phase change due to the Z-axis rotation in step S620 (step S620: NO), the communication system 1 completes the rotation adjustment (step S635). ). In step S635, the transmission / reception side and the reception side perform notification and confirmation of "adjustment of transmission side rotation" using the control radio. For example, “control-side rotation adjustment completion” is notified from the reception-side communication device 20 to the transmission-side communication device 10 using control radio. The transmission-side communication device 10 receives this control radio and recognizes “transmission-side rotation adjustment completion”.

  If the axis deviation estimation / control unit 26 of the communication device 20 on the receiving side determines that the X axis rotation of the entire range has been confirmed during the adjustment of the X axis rotation (step S625: YES), the rotation adjustment is performed. Incomplete is displayed (step S640), and the operation flow of FIG. 25 is terminated. In the process of step S640, the control side is used to notify “transmission side rotation adjustment incomplete” from the reception side to the transmission side.

26 and 27 are diagrams showing the characteristics of the phase change used in the rotation adjustment.
FIG. 26 shows the receiving position on the receiving side. In the figure, four reception positions in the XZ plane including the receiving-side antenna element 22 are PA, PB, PC, and PD. The positions PA, PB, PC, and PD are positions on the circumference where the receiving-side antenna element 22 is arranged, and the central angle θ _o of each position is 90 [°], 67.5 [°], 22.5 [°] and 0 [°].

FIG. 27 is a graph showing a phase change graph on the reception side when the transmission side rotates in the Z axis. The horizontal axis of the graph shown in FIG. 27 is the angle of Z-axis rotation on the transmission side, and the vertical axis is the phase change amount on the reception side. Reference sign L _PA indicates the position PA, reference sign L _PB indicates the position PB, reference sign L _PC indicates the position PC, and reference sign L _PD indicates the relationship between the transmission side Z-axis rotation angle and the phase change amount.

The graph shown in FIG. 27 is obtained by replacing the “deviation rotation angle α [°]” on the horizontal axis in FIG. 23 with “the angle [°] of the transmission side Z-axis rotation”. That is, the phase θ ₁ with respect to the angle θ corresponding to the position of the antenna element 22 on the receiving side is calculated by the equation (7) described in FIG. 21, and the reference phase θ _o and The phase change amount Δθ [°] can be obtained from the difference between the two.

  When the transmission side rotates in the Z axis, the phase changes at positions other than on the X axis, for example, reception at positions PA, PB, and PC. Further, the amount of phase change varies depending on the vertical component (Z-axis component) of the distance from the X-axis to the positions PA, PB, PC, and PD (position of the antenna element 22). Further, as the distance from the X axis is longer (distance between position PA and X axis> distance between position PB and X axis> distance between position PC and X axis), the phase change becomes larger. Conversely, when the transmission side rotates on the X axis, the phase at the position on the Z axis (position PD) does not change, and the phase change increases as the distance from the Z axis increases.

  In the operation flow of FIG. 25, the graph shown in FIG. 27 utilizes the feature of phase change in the determination processing in step S605 and step S620. That is, in step S605, there is a phase change in the antenna element 22 that is not on the X axis (for example, the antenna element 22 at the positions PA, PB, and PC), and the antenna element 22 on the X axis (for example, the antenna at the position PD). It is determined whether there is a phase change in the element 22). In step S620, there is a phase change in the antenna element 22 on the Z axis (for example, the antenna element 22 at positions PB, PC, and PD), and the antenna element 22 on the Z axis (for example, at the position PA) It is determined whether there is a phase change in the antenna element 22).

The position of the antenna element 22 in the receiving-side array antenna 21 may be devised, such as providing the antenna element 22 on the X axis. Further, the position of the antenna element can be moved on the X-axis by using the Y-axis rotation shown in FIG. FIG. 28 is a diagram illustrating movement of the position of the antenna element 22 on the reception side on the X axis using the Y axis rotation. In the figure, the antenna element 22 located at the position PE is moved to the position PD ′ on the X axis using the Y-axis rotation, so that, for example, the antenna element 22 located at the position PB is moved on the Z-axis. Move to position PA ′. When the position of the antenna element 22 is moved on the X axis using the Y-axis rotation, the antenna element 22 is tilted and the direction of the polarization is slightly shifted. For example, although mixed a little H polarization components in the V-polarized wave, there is no change in phase with respect to the Z-axis rotation of the array antenna 21, a characteristic such as L _PD in Figure 27. Alternatively, it is possible to adjust the axis deviation by utilizing the difference in the amount of phase change, instead of making a determination based on whether or not there is a simple phase change. If this difference in phase change is utilized, the antenna element 22 is arranged at the position PA and position PD of the central angle θ _o = 90 [°], 0 [°] on the circumference where the antenna element 22 is arranged. Even if not, a determination is made based on the phase change of the antenna element 22 arranged at another position, for example, the position PB of each center θ _o = 67.5 [°], 22.5 [°], and PC. Also good.

  According to the first embodiment and the second embodiment described above, the communication system that performs wireless communication using OAM waves adjusts the direction of radio wave radiation on the transmission side. In order to adjust the direction of radio wave radiation on the transmitting side, processing is performed in the following order. That is, whether the receiving side needs to adjust the direction based on the characteristics of the phase change of the received signal assumed from the rotation of the radio wave radiation on the transmitting side with respect to the phase of the received signal obtained from all antenna elements of the receiving array antenna. Determine whether. When direction adjustment is necessary based on the characteristics of the phase change determined by the reception side, the communication system performs direction adjustment of the transmission array antenna in the following order. First, the communication system performs adjustment to rotate the array antenna on the transmission side in the Z axis (vertical direction). Next, the communication system performs adjustment for rotating the array antenna on the transmission side in the X axis (horizontal direction orthogonal to the transmission direction).

  In order to determine whether or not direction adjustment is necessary in the adjustment of the direction of radio wave radiation on the transmission side described above, reception at all antenna elements of the reception array antenna assumed by the rotation of the axis of radio wave radiation on the transmission side. You may utilize the characteristic (characteristic) of the phase change of a signal.

  Further, in order to determine whether or not the direction adjustment is necessary in the adjustment of the direction of the radio wave radiation on the transmission side described above, the reception array when rotated around an axis different from the rotation axis for adjusting the radio wave radiation on the transmission side The characteristics (features) of the phase change of the received signal at the antenna may be used.

The transmission side has a movable mechanism for rotating the array antenna about two axes, the X axis (horizontal direction orthogonal to the transmission direction) and the Z axis (vertical direction).
Alternatively, the transmission side includes a three-dimensional array antenna in which a large number of antenna elements are three-dimensionally arranged, and a selection unit that selects a sub-array from the three-dimensional array antenna. The selection unit selects an antenna element in a partial region from the three-dimensional array antenna, and configures a subarray used as a transmission array antenna. The selection unit adjusts the axial rotation of the transmission array antenna by selecting another subarray that matches the axial rotation from the currently selected subarrays.

[Third Embodiment]
Up to the second embodiment, the method of adjusting the axial deviation due to the rotation on the transmission side based on the phase obtained for the antenna element 22 on the reception side has been described. In the third embodiment, the transmitting and receiving array antennas are adjusted in order.

FIG. 29 is a diagram illustrating a situation in which the direction deviation is adjusted in order on the transmission side and the reception side.
FIG. 29 (a) is a diagram showing a direction misalignment state on both the transmission side and the reception side. The transmitting-side array antenna 13a is a state in which the transmitting-side array antenna 13 on the XZ plane is rotated in the Z axis, and the receiving-side array antenna 21a is the receiving-side array antenna 21 on the XZ plane. This is the state rotated in the Z-axis. The centers of the array antenna 13 and the array antenna 13a coincide, and the centers of the array antenna 21 and the array antenna 21a coincide. The direction DS1 of the array antenna 13a on the transmission side and the direction DR1 of the array antenna 21a on the reception side do not coincide with the center of the array antenna 21a on the reception side and the center of the array antenna 13a on the transmission side. In this state, the axis adjustment is not performed at all on both the transmission side and the reception side.

  FIG. 29B is a diagram illustrating a state in which only the direction deviation on the transmission side has been adjusted. The direction DS2 of the array antenna 13 on the transmission side coincides with the center of the array antenna 21a on the opposite reception side. On the other hand, the direction DR2 of the receiving-side array antenna 21a does not coincide with the center of the opposing transmitting-side array antenna 13. The adjustment method described in the previous second embodiment is used for adjustment on the transmission side to change from the state of FIG. 29 (a) to the state of FIG. 29 (b).

  FIG. 29C is a diagram illustrating a state in which the direction deviation has been adjusted on both the transmission side and the reception side. The direction DS3 of the array antenna 13 on the transmission side and the direction DR3 of the array antenna 21 on the reception side coincide with the center of the array antenna 21 on the reception side and the center of the array antenna 13 on the transmission side. In order to change from the state of FIG. 29 (a) or FIG. 29 (b) to the state of FIG. 29 (c), the communication system 1 performs an adjustment operation described later. In this state, there is no influence of axis misalignment in both transmission and reception, and wireless communication using OAM waves can be performed without any problem.

FIG. 30 is a diagram illustrating an operation flow of direction deviation adjustment for both transmission and reception in the communication system 1.
To start the operation of the operation flow shown in the figure, first, adjustment of the communication device 10 on the transmission side is performed (step S705). In the process of step S705, the control radio is used to notify / confirm “start of rotation adjustment on the transmission side” between the transmission side and the reception side. For example, the receiving-side communication device 20 notifies the transmitting-side communication device 10 of “starting adjustment of rotation on the transmitting side” by control radio, and the communication device 10 receives the control radio and receives “ "Adjustment start" is recognized. Alternatively, the transmission-side communication device 10 notifies the reception-side communication device 20 of “start of adjustment of rotation on the transmission side” by the control radio, and the communication device 20 receives the control radio and receives “the rotation of the transmission-side rotation”. "Adjustment start" is recognized. In the adjustment process on the transmission side in step S705, the biaxial rotation of the array antenna 13 on the transmission side in the state shown in FIG. Further, this adjustment method is performed by the method of adjusting the axial deviation described in the second embodiment.

  The axis deviation estimation / control unit 26 of the communication device 20 determines whether or not the phase at the direction deviation is within an allowable range (step S710). When it is determined that the phase deviation phase is within the allowable range (step S710: YES), the axis deviation estimation / control unit 26 displays the completion of adjustment (step S715) and ends the process. In the adjustment completion display process in step S715, the communication apparatus 20 notifies the communication apparatus 10 of “adjustment of rotation on the transmission side” by control radio.

  On the other hand, if the axis deviation estimation / control unit 26 of the communication device 20 determines that the phase deviation is beyond the allowable range (step S710: NO), the transmission / reception is switched to become a new transmission side. The communication device 20 is adjusted (step S720). In order to shift to the process of step S720, the control radio notifies and confirms “adjustment start with exchange of transmission and reception” between the transmission side and the reception side. For example, the receiving-side communication device 20 notifies the transmitting-side communication device 10 of “adjustment start with exchange of transmission / reception” by a control radio, and the communication device 10 receives the control radio and receives “adjustment start with exchange of transmission / reception”. Is recognized. Alternatively, the transmission-side communication device 10 notifies the reception-side communication device 20 of “adjustment start after switching transmission / reception” by the control radio, and the communication device 20 receives the control radio and receives “adjustment start after transmission / reception switching”. Is recognized. Then, the communication device 10 performs the processing of the communication device 20 in the adjustment process on the transmission side in step S705, and the communication device 20 performs the processing of the communication device 10.

  In the adjustment process in which transmission / reception is switched in step S720, the biaxial rotation of the array antenna 21 which is on the reception side and becomes the transmission side in the state shown in FIG. 29B is adjusted. The axis deviation estimation / control unit 15 of the communication apparatus 10 determines whether or not the direction deviation (difference from the original phase) is within an allowable range (step S725). When the axis deviation estimation / control unit 15 determines that the direction deviation is within the allowable range (step S725: YES), the communication system 1 completes the adjustment in which transmission / reception is switched (step S730), and ends the process. When the adjustment is completed, the communication system 1 enters the state shown in FIG. When the adjustment in step S730 is completed, the communication device 10 that has become the receiving side by switching transmission / reception to the communication device 20 that has become the transmitting side by switching transmission / reception uses the control radio to “adjust the transmission and reception switching”. “Complete”.

  Note that the determination in step S725 can be a phase range in which a plurality of OAM modes used for communication can be identified without problems. For example, in the case of wireless communication that uses the OAM modes L1 to L3 in a multiplexed manner, the phase can be within an allowable range of about ± 10 [°]. When it is determined that the direction deviation exceeds the allowable range (step S725: NO), the axis deviation estimation / control unit 15 of the communication device 10 displays the transmitted and received adjustment amount over (step S735) and ends the operation. In the process of step S735 before the end of the operation, the control wireless communication is used to notify the transmission-side communication device 20 that the transmission-and-reception communication device 20 has been exceeded.

[Fourth Embodiment]
In the present embodiment, a method for adjusting the direction of an OAM wave generated by a method different from the above-described embodiment will be described.

  From the first embodiment to the third embodiment, the array antenna 13 including the antenna elements 14 arranged in a circle transmits an OAM wave, and a similar array antenna 21 is transmitted through each antenna element 22 with an OAM wave. Was based on the form of receiving. However, the adjustment of the axis shift utilizing the phase change of the OAM wave is not necessarily limited to the OAM wave transmitted using the array antenna. Therefore, two examples shown in FIGS. 31 and 32 are given as modes for transmitting OAM waves in addition to the array antenna.

  FIGS. 31 and 32 are configuration diagrams of a communication system using OAM waves generated by a method different from the above-described embodiment. FIG. 31 shows a configuration example of a communication system 1a that uses a cut-in parabolic antenna to generate an OAM wave, and FIG. 32 shows a configuration example of a communication system 1b that uses transmission of a dielectric with a step to generate an OAM wave. Show.

  A communication system 1 a illustrated in FIG. 31 includes a communication device 51 and a communication device 55. In the figure, the same parts as those of the communication system 1 according to the first embodiment shown in the figure are denoted by the same reference numerals, and the description thereof is omitted. The communication device 51 is different from the communication device 10 shown in FIG. 1 in that the cutout parabolic antenna 52 is provided instead of the array antenna 13 and the phase adjustment unit 12 is not provided. The communication device 55 is different from the communication device 20 shown in FIG. 1 in that a cut-out parabolic antenna 56 is provided instead of the array antenna 21, a plurality of array antennas 57 are provided around the cut-out parabolic antenna 56, and The phase adjustment unit 23 is not provided.

  By using the cut-in parabolic antenna 52, in the transmission of the OAM wave, the function of setting the phase with respect to the signal input to each antenna element 14 on the transmission side becomes unnecessary. On the other hand, on the receiving side, in order to detect whether or not there is an axis misalignment adjustment (whether or not there is an axis misalignment) and to detect the adjustment amount (deviation amount), the receiving side cut-out parabolic antenna 56 An array antenna 57 is arranged around the circumference. The phase measurement unit 25 measures the phase based on signals from all antenna elements of the array antenna 57. The axis deviation estimation / control unit 26 estimates the axis deviation using the phase measurement result, and can adjust the axis deviation of the cut parabolic antenna 56 based on the estimation. Note that the phase changes by 360 [°] at the cut position of the cut parabolic antenna 52 used for generating the OAM wave. The number of cuts in the cut parabolic antenna 52 determines the OAM mode. That is, if the cut parabolic antenna 52 has cuts at one, two, three,..., OAM modes L1, L2, L3,.

  FIG. 32 shows a mode in which radio waves are transmitted through a stepped dielectric and communicated as OAM waves. A communication system 1b illustrated in FIG. 32 includes a communication device 61 and a communication device 65. In the figure, the same parts as those of the communication system 1 according to the first embodiment shown in FIG. The communication device 61 is different from the communication device 10 shown in FIG. 1 in that instead of the array antenna 13, a directional antenna 62 and a dielectric 63 having a step for transmitting radio waves transmitted by the directional antenna 62 are provided. And the phase adjustment unit 12 is not provided. The communication device 65 differs from the communication device 20 shown in FIG. 1 in that instead of the array antenna 21, a directional antenna 66 and a dielectric 67 having a step for transmitting radio waves transmitted by the directional antenna 66 are provided. It is a point provided, a point provided with a plurality of array antennas 68 around the dielectric 67, and a point provided with no phase adjustment unit 23.

  Also in this configuration example, as in FIG. 31, phase setting is unnecessary, and the array antenna 68 is arranged around the reception-side dielectric 67. The dielectric 63 used for generating the OAM wave has eight steps radially. When the OAM mode is set to L1, the step where the path difference passing through the dielectric 63 is maximized is one place, and the phase of the path difference is changed by 360 [°] at the position of the step.

  Both of the communication system 1a of FIG. 31 and the communication system 1b of FIG. 32 have a phase based on signals from all antenna elements of the array antennas 57 and 68 arranged around the parabolic antenna 56 or the dielectric 67 on the receiving side. taking measurement. The axis deviation estimation / control unit 26 of the communication devices 55 and 65 estimates the axis deviation from the measured phases of all the antenna elements, and the cut parabolic antenna 56 or the directional antenna 66 and the dielectric are estimated by the estimation. 67 is translated to adjust the axis deviation.

[Fifth Embodiment]
In the present embodiment, the direction adjustment of wireless communication other than the OAM wave is performed using the OAM wave. The first to fourth embodiments are based on the premise that the wireless communication to be adjusted for the antenna direction uses OAM waves. However, in general, a dedicated test signal different from wireless communication may be used for antenna direction adjustment. Similarly, OAM waves can be used as test signals for antenna direction adjustment, and other wireless communication can be performed using the antenna whose direction is adjusted.

  FIG. 33 is a diagram showing a table of types of radio waves used for communication, methods used for axis adjustment (coarse adjustment / fine adjustment), and combinations of components to be shared. By combining these, communication systems with various mechanisms can be considered.

  FIG. 34 shows a configuration example of a communication system 1c having a mechanism in which candidates indicated by underlining are selected from communication, an axis adjustment method, and shared components from the table shown in FIG. That is, from the table shown in FIG. 33, “other wireless communication that is not an OAM wave” is used for communication, “adjustment based on received radio wave intensity” is used for coarse adjustment, and “OAM wave is used for fine adjustment for phase characteristics. "Direction adjustment by", "Transmission / reception array antenna" is selected for each shared component.

  FIG. 34 is a configuration diagram of the communication system 1c of the present embodiment. The configuration of the communication system 1c is similar to the configuration of the communication system 1 of the first embodiment shown in FIG. The communication system 1 c includes a communication device 70 and a communication device 80. Hereinafter, a case where the transmission side is the communication device 70 and the reception side is the communication device 80 will be described as an example. In the figure, the same parts as those of the communication system 1 according to the first embodiment shown in FIG. In the figure, a portion indicated by a dotted line is another wireless communication component, and an additional portion of the present embodiment relative to the other wireless communication component is the same as the communication system 1 of the first embodiment shown in FIG. It is the same. A portion common to the first embodiment is used for adjusting the axial deviation (in particular, fine adjustment described later with reference to FIG. 35).

  The communication device 70 includes a test signal generation unit 72, a phase adjustment unit 73, a communication signal generation unit 74, an adjustment unit 75, an array antenna 13, an axis deviation estimation / control unit 15, a movable unit 16, and a control radio unit 17. In the communication device 70 on the transmitting side, other wireless communication components (corresponding to components performing communication by OAM in FIG. 1) include a communication signal generator 74, an adjustment unit 75, and the array antenna 13. The array antenna 13 is shared with other wireless communications for axis adjustment.

  The communication signal generator 74 is the same as the signal generator 11 of FIG. The adjustment unit 75 adjusts the amplitude and phase of the transmission signal fed to each antenna element 14 and corresponds to the phase adjustment unit 12 in FIG. However, they are used for other wireless communications that are not OAM waves. Therefore, the communication signal generation unit 74 performs modulation in accordance with wireless communication in addition to the transmission signal generation function. In addition, the adjustment unit 75 may perform the same phase adjustment on a plurality of antenna elements 14 or change the signal amplitude for each antenna element 14 in other wireless communication different from OAM.

  Subsequently, a configuration added on the transmission side in the present embodiment will be described. The axis deviation estimation / control unit 15, the movable unit 16, and the control radio unit 17 are all the same as those in the first embodiment shown in FIG. Functions that the communication device 70 has and that the communication device 10 of FIG. 1 does not have are realized by the test signal generation unit 72 and the phase adjustment unit 73. The test signal generator 72 generates an input signal to the antenna that becomes an OAM wave wirelessly. The phase adjustment unit 73 adjusts a different phase for each antenna element 14. The phase adjustment unit 73 for the test OAM signal in FIG. 34 has the same function as the phase adjustment unit 12 in the wireless communication using the OAM in FIG.

  The configuration of the communication device 70 on the transmission side has been described so far, and the communication device 80 on the reception side will be described from here. The communication device 80 includes an array antenna 21, an adjustment unit 83, a communication signal demodulation unit 84, a phase measurement unit 25, an axis deviation estimation / control unit 26, a movable unit 27, and a control radio unit 28. The adjustment unit 83 and the communication signal demodulation unit 84 of the communication device 80 correspond to the phase adjustment unit 12 and the signal demodulation unit 24 of the first embodiment shown in FIG. The adjustment unit 83 adjusts the amplitude and phase of the reception signal for each antenna element 22. However, in FIG. 34, in order to perform other wireless communication that is not an OAM wave, the adjustment unit 83 performs other adjustments different from OAM when performing adjustment for each antenna element on the reception side, similarly to the communication device 70 on the transmission side. In communication, the same phase adjustment is performed by a plurality of antenna elements 22 or the signal amplitude is changed for each antenna element 22. The communication signal demodulation unit 84 receives the reception signal from the adjustment unit 83 and also performs demodulation in accordance with the modulation performed by the communication device 70.

  In addition, the phase measurement unit 25, the axis deviation estimation / control unit 26, the movable unit 27, and the control radio unit 28 of the communication device 80 are the same as those in the first embodiment shown in FIG. However, in FIG. 1, the OAM wave is used for both the adjustment of the axis shift of the array antenna 21 and the wireless communication. However, the communication device 80 of FIG. 34 performs other radio communication other than the OAM wave, and the OAM wave is not aligned with the axis shift of the array antenna. Use only for adjustment. In particular, the OAM wave is used for fine adjustment of the axial deviation described later with reference to FIG.

  With the configuration of the communication device 70 and the communication device 80 described above, the communication system 1c is configured to use an OAM wave as a test signal in the direction adjustment of other wireless communication. A switching operation between other wireless communication and axis adjustment using OAM waves as test signals in the communication system 1c will be described. Therefore, an example in which an OAM wave is used as a test signal in other radio communication direction adjustment will be described.

  FIG. 35 shows an operation flow of the communication system 1c in switching between another radio signal and the OAM test signal. This operation flow relates to antenna direction adjustment before performing communication using other radio signals that are not OAM waves.

  In FIG. 35, first, rough direction adjustment of the receiving-side array antenna is performed based on the radio field intensity (step S805). In this rough direction adjustment, control radio is used to notify and confirm “start of coarse adjustment based on radio wave intensity of received signal” between transmission and reception. In this rough direction adjustment, a method other than the radio wave intensity may be used, such as using a sighting device such as a scope, or adjusting the antenna direction to a direction obtained by calculation from information on the latitude and longitude of the transmission / reception antenna. Thereafter, the communication system 1c proceeds with processing in the following order.

  The axis misalignment estimation / control unit 26 of the communication device 80 on the receiving side determines whether or not the coarse direction adjustment of the array antenna has been completed (step S810). If the axial deviation estimation / control unit 26 determines that the rough adjustment has not been completed (step S810: NO), the communication system 1c performs the rough direction adjustment in step S805 again. If the axis deviation estimation / control unit 26 of the communication device 80 determines that the rough adjustment has been completed (step S810: YES), the communication device 70 sets the generation of the OAM wave in the test signal (step S815).

  When shifting to the adjustment using the OAM wave for the test signal, the communication device 80 notifies the communication device 70 of “end of coarse adjustment” using the control radio, and the OAM between the communication device 70 and the communication device 80 is notified. Mutually notify and confirm the start of fine adjustment by waves. The communication device 80 receives the OAM wave and performs a direction deviation fine adjustment process (step S820). The communication device 80 performs fine adjustment of the direction of the array antenna by the OAM wave by this direction deviation fine adjustment processing.

  The fine adjustment processing of the direction of the array antenna in step S820 is the same processing as in the first to third embodiments. That is, the communication device 80 or the processing similar to steps S105 to S130 in FIG. 18, the processing similar to steps S605 to S630 in FIG. 25, or the processing similar to steps S705 to S720 in FIG. The communication device 80 and the communication device 70 perform axis misalignment adjustment using the phase characteristics of the OAM wave.

  The axis deviation estimation / control unit 26 of the communication device 80 on the receiving side or the axis deviation estimation / control unit 15 of the communication device 70 determines whether or not the direction fine adjustment by the test signal of the OAM wave is finished (step S825). If the axis deviation estimation / control unit 26 of the communication device 80 on the receiving side or the axis deviation estimation / control unit 15 of the communication device 70 determines that fine adjustment has not been completed (step S825: NO), the communication system In step 1c, the direction fine adjustment in step S820 is performed again. If the axis deviation estimation / control unit 26 of the communication device 80 on the receiving side or the axis deviation estimation / control unit 15 of the communication device 70 determines that the fine adjustment has been completed (step S825: YES), the process of step S830 is performed. That is, the axis deviation estimation / control unit 26 of the communication device 80 on the receiving side or the axis deviation estimation / control unit 15 of the communication device 70 determines whether the axis deviation is within an allowable range (step S830). When the axis deviation estimation / control unit 26 of the communication device 80 on the receiving side or the axis deviation estimation / control unit 15 of the communication device 70 determines that the axis deviation is within the allowable range (step S830: YES), the communication device 70 And the communication apparatus 80 switches to the communication signal of another radio | wireless communication, and starts communication (step S835).

  When communication is started in step S835, the control radio transmits from the communication device 80 or communication device 70 on the reception side to the communication device 70 or communication device 80 on the transmission side, “within the allowable range by the axis adjustment by the OAM wave. ”And from the receiving side to the transmitting side (or from the transmitting side to the receiving side) to notify“ start normal communication ”, thereby confirming each other between sending and receiving.

  On the other hand, if the axis deviation estimation / control unit 26 of the communication device 80 on the receiving side or the axis deviation estimation / control unit 15 of the communication device 70 determines that the axis deviation is not within the allowable range (step S830: NO), the direction It is displayed that the fine adjustment (movement adjustment) is not successful (step S840). The axis deviation estimation / control unit 15 of the communication device 80 on the receiving side or the communication device 70 uses the control radio to transmit to the communication device 70 or the communication device 80 on the transmission side. Notify ”.

Here, in relation to the coarse adjustment / fine adjustment, for example, in other wireless communication, the distance between transmission and reception is 400 m, and the angle ≦ 0.1 [°] at the position of the reception antenna with respect to the transmission antenna direction by the coarse adjustment is an allowable range. Assume. In addition, in the first stage of antenna direction adjustment, it is considered that only coarse adjustment of angle ≦ 0.3 [°] can be performed. Naturally, in these assumptions, the angle of the allowable range is exceeded when only the coarse adjustment is performed, so the communication system 1c performs the fine adjustment using the OAM wave of the present embodiment. In this case, with respect to the difference from a state where there is no ideal axis deviation, that is, the rotation angle α = 0 [°] of the axis deviation shown in FIG. About 5 [°] is required. In FIG. 23, this accuracy value is obtained by using an antenna element of θ _o = 112.5 [°] when the rotational angle α of the axial deviation is in the plus range and θ _o = 67.5 [°] when the rotational angle α is negative. When α = ± 6 [°], Δθ = ± 44.5 [°], and changes substantially proportionally (linearly) in the range of α = 0 to ± 6 [°]. It can be calculated as 74 [°] (≈0.1 × 44.5 / 6). Therefore, the identification accuracy 0.5 [°] of the phase change amount Δθ due to the axis deviation is higher than 0.74 [°] calculated from the phase change feature shown in FIG. 1 [°] can be adjusted sufficiently.

  Alternatively, as another form such as the first to fourth embodiments, in communication using OAM waves, the distance between transmission and reception is 100 m, and the allowable range is an angle ≦ 0 with respect to the direction of the transmission antenna. .03 [°]. Also, consider the case where the angle can only be set to an angle ≦ 0.05 [°] by coarse adjustment. From these assumptions, if the discrimination accuracy value of the shift phase change amount Δθ can be set to 0.1 [°] by fine adjustment using the OAM wave, the allowable range condition can be sufficiently satisfied. Similarly to the above description related to the fine adjustment and the allowable range, from FIG. 23, the phase change amount Δθ is within 0.22 (≈0.03 × 44.5 / 6), and the allowable range angle ≦ 0.03. This corresponds to a discrimination ability with a precision of more than twice that of [°].

  According to the embodiment described above, the communication system includes a first communication device (for example, communication devices 10, 51, 61, and 70) and a second communication device (for example, communication devices 20, 55, 65, and 80). Have. The first antenna (for example, the array antenna 13, the parabolic antenna 52, and the dielectric 63) of the first communication device transmits an OAM wave. The second antenna (for example, the array antennas 21, 57, 68) of the second communication device receives the OAM wave transmitted from the first antenna. The control unit (for example, the axis deviation estimation / control unit 26) of the second communication device is configured to radiate a radio wave from the first antenna based on the phase of the OAM wave received at each of the plurality of antenna elements of the second antenna. The deviation angle of the first antenna is obtained, and the adjustment of the vertical direction of the first antenna and the adjustment of the horizontal direction of the first antenna are individually performed based on the obtained angle.

  The control unit of the second communication device transmits from the first antenna when there is a difference between the phase of the OAM wave received at each of the plurality of antenna elements of the second antenna and the radio wave radiation direction from the first antenna. Based on the characteristics of the phase change when each of the plurality of antenna elements of the second antenna receives the received signal, the angle of the vertical or horizontal deviation of the radio wave radiation direction from the first antenna is obtained. Also good.

Further, the control unit of the second communication device determines whether adjustment in the horizontal direction or the vertical direction is necessary based on the phase of the OAM wave received by each of the plurality of antenna elements included in the second antenna. Then, the control unit of the second communication device adjusts the vertical rotation of the first antenna when determining that vertical adjustment is necessary, and adjusts the first antenna when determining that horizontal adjustment is required. Adjust the horizontal rotation.
Alternatively, the control unit of the second communication device may perform before or after rotating one of the horizontal direction and the vertical direction of the first antenna based on the phase of the OAM wave received at each of the plurality of antenna elements of the second antenna. Then, it is determined whether or not there is a phase change in the other direction. Then, the control unit of the second communication device adjusts the vertical rotation of the first antenna when it is determined that there is a horizontal phase change, and when it determines that there is a vertical phase change, Adjust the horizontal rotation of the antenna.

In addition, the first communication device includes a movable portion of a mechanism that rotates the direction of the first antenna in the horizontal direction and the vertical direction based on adjustment by the control unit of the second communication device.
Alternatively, the first communication device has a three-dimensional array in which a plurality of antenna elements are three-dimensionally arranged, and the first antenna is configured by an antenna element selected from the antenna elements included in the three-dimensional array. The selection unit of the first communication device selects an antenna element to be used as the first antenna from the antenna elements included in the three-dimensional array based on the adjustment by the control unit.

  According to the above-described embodiment, wireless communication using OAM waves can be realized by accurately adjusting the transmission / reception axis. Also in other wireless communications, the transmission and reception axes can be adjusted with high accuracy by using OAM waves as test signals.

  Some functions such as the axis deviation estimation / control unit 15 of the communication devices 10, 51, 61, and 70 and the axis deviation estimation / control unit 26 of the communication devices 20, 55, 65, and 80 in the above-described embodiment are performed by a computer. You may make it implement | achieve, You may implement | achieve using hardware, such as ASIC (Application Specific Integrated Circuit), PLD (Programmable Logic Device), FPGA (Field Programmable Gate Array). When some functions such as the axis deviation estimation / control unit 15 of the communication devices 10, 51, 61, 70 and the axis deviation estimation / control unit 26 of the communication devices 20, 55, 65, 80 are realized by a computer, The program for realizing the function may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read by a computer system and executed. Here, the “computer system” includes an OS and hardware such as peripheral devices. The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory inside a computer system serving as a server or a client in that case may be included and a program held for a certain period of time. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes designs and the like that do not depart from the gist of the present invention.

  The present invention can be used for a communication system that performs communication using OAM waves. In addition, it can be used for highly accurate direction adjustment of a transmission / reception antenna in wireless communication.

DESCRIPTION OF SYMBOLS 1, 1a, 1b, 1c ... Communication system 10, 20, 51, 55, 61, 65, 70, 80 ... Communication apparatus 11 ... Signal generation part 12, 23, 73 ... Phase adjustment part 13, 21, 57, 68 ... Array antennas 14, 22, 132 ... Antenna elements 15, 26 ... Axial misalignment estimation / control unit 16, 27 ... Movable unit 17, 28 ... Control radio unit 24 ... Signal demodulation unit 25 ... Phase measurement unit 31 ... Plate 32 ... Back support Part 33 ... Outer frame 40 ... Mounting plate 41 ... Bottom plate 42 ... Post 44 ... Arms 45, 46, 47, 48 ... Rotating parts 52, 56 ... Parabolic antennas 62, 66 ... Directional antennas 63, 67 ... Dielectric 72 ... Test signal generation unit 74 ... communication signal generation unit 75, 83 ... adjustment unit 84 ... communication signal demodulation unit 131 ... three-dimensional array

Claims (7)

An antenna adjustment method in a communication system having a first communication device and a second communication device,
A transmission step in which the first antenna of the first communication device transmits an OAM (Orbital Angular Momentum) wave;
A receiving step in which a second antenna of the second communication device receives the OAM wave;
Based on the phase of the OAM wave received by each of the plurality of antenna elements of the second antenna, the control unit of the second communication device obtains the angle of deviation of the radio wave radiation direction from the first antenna, A control step for individually adjusting the vertical direction of the first antenna and adjusting the horizontal direction of the first antenna based on the obtained angle;
I have a,
In the control step,
The plurality of antenna elements included in the second antenna, which are obtained by the information indicating the phase of the OAM wave received by each of the plurality of antenna elements included in the second antenna and the angle of deviation in the radio wave radiation direction from the first antenna. By comparing the information indicating the phase of the OAM wave received by each of the antenna elements, the vertical or horizontal deviation angle of the radio wave radiation direction from the first antenna is obtained.
An antenna adjustment method characterized by that. In the control step, the movable part of the first communication device rotates the direction of the first antenna in the horizontal direction or the vertical direction based on the obtained angle.
The antenna adjustment method according to claim 1 . An antenna adjustment method in a communication system having a first communication device and a second communication device,
A transmission step in which the first antenna of the first communication device transmits an OAM (Orbital Angular Momentum) wave;
A receiving step in which a second antenna of the second communication device receives the OAM wave;
Based on the phase of the OAM wave received by each of the plurality of antenna elements of the second antenna, the control unit of the second communication device obtains the angle of deviation of the radio wave radiation direction from the first antenna, A control step for individually adjusting the vertical direction of the first antenna and adjusting the horizontal direction of the first antenna based on the obtained angle;
Have
The first communication device has a three-dimensional array in which a plurality of antenna elements are arranged in three dimensions,
The first antenna is constituted by an antenna element selected from the antenna elements of the three-dimensional array,
In the control step, the selection unit of the first communication device selects an antenna element to be used as the first antenna from the antenna elements of the three-dimensional array, based on the obtained angle.
Features and to luer antenna adjusting method that. The control unit further includes a determination step of determining whether adjustment in the horizontal direction or the vertical direction is necessary based on the phase of the OAM wave received at each of the plurality of antenna elements of the second antenna. ,
In the control step, the vertical rotation of the first antenna is adjusted when the determination step determines that vertical adjustment is necessary, and the horizontal adjustment is determined by the determination step. In the case of adjusting the horizontal rotation of the first antenna,
The antenna adjustment method according to any one of claims 1 to 3, wherein the antenna adjustment method is performed. Based on the phase of the OAM wave received at each of the plurality of antenna elements of the second antenna, the control unit rotates one of the first antenna in the horizontal direction or the vertical direction before and after rotating the other. A determination step for determining whether there is a change in direction phase;
In the control step, when the determination step determines that there is a horizontal phase change, the vertical rotation of the first antenna is adjusted, and the determination step determines that there is a vertical phase change. Adjusting the horizontal rotation of the first antenna when
The antenna adjustment method according to any one of claims 1 to 3, wherein the antenna adjustment method is performed. A communication system having a first communication device and a second communication device,
The first communication device includes a first antenna that transmits an OAM (Orbital Angular Momentum) wave,
The second communication device is
A second antenna for receiving the OAM wave;
Based on the phase of the OAM wave received at each of the plurality of antenna elements of the second antenna, an angle of deviation of the radio wave radiation direction from the first antenna is obtained, and the first angle is obtained based on the obtained angle. A control unit that individually adjusts the vertical direction of one antenna and the horizontal direction of the first antenna ;
The control unit obtains the information indicating the phase of the OAM wave received by each of the plurality of antenna elements of the second antenna and the angle of deviation of the radio wave radiation direction from the first antenna, By comparing the information indicating the phase of the OAM wave received by each of the plurality of antenna elements of the two antennas, the vertical or horizontal deviation angle of the radio wave radiation direction from the first antenna is obtained.
A communication system characterized by that. A communication system having a first communication device and a second communication device,
The first communication device includes a first antenna that transmits an OAM (Orbital Angular Momentum) wave,
The second communication device is
A second antenna for receiving the OAM wave;
Based on the phase of the OAM wave received at each of the plurality of antenna elements of the second antenna, an angle of deviation of the radio wave radiation direction from the first antenna is obtained, and the first angle is obtained based on the obtained angle. A control unit that individually adjusts the vertical direction of one antenna and the horizontal direction of the first antenna;
The first communication device has a three-dimensional array in which a plurality of antenna elements are arranged in three dimensions,
The first antenna is constituted by an antenna element selected from the antenna elements of the three-dimensional array,
The control unit causes the selection unit of the first communication device to select an antenna element to be used as the first antenna from the antenna elements of the three-dimensional array based on the obtained angle.
A communication system characterized by that.

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