JP2015220735A - Antenna direction adjusting device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide antenna direction adjusting device and method that measure the inclination of a polarization plane of an antenna by a simple method.SOLUTION: A maximum power searching unit 131 of a controller 13 equipped to an antenna direction adjusting device 1 changes the azimuth of a pan direction and the elevation angle of a tilt direction while the polarization angle is set to any value, and searches the direction(azimuth θ, elevation angle θ, polarization angle θ) of a reception antenna 11 at which the reception power is maximum. A polarization angle fine adjusting unit 132 finely adjusts the polarization angle on the basis of the direction (azimuth θ, elevation angle θ, polarization angle θ) searched by the maximum power searching unit 131, changes the azimuth of the pan direction and specifies the polarization angle θat which the deterioration amount of a bit error rate is minimum. A tilt direction elevation angle finely adjusting unit 133 finely adjusts the elevation angle of the tilt direction on the basis of the direction (azimuth θ, elevation angle θ, polarization angle θ) in which the reception power is maximum when the polarization angle θis specified by the polarization angle finely adjusting unit 132, changes the azimuth angle of the pan direction and specifies the elevation angle θat which the deterioration amount of the bit error rate is minimum.

Description

  The present invention relates to an antenna direction adjustment apparatus and method for adjusting the direction of an antenna, and more particularly to a technique for measuring the inclination of the polarization plane of linearly polarized waves.

  Conventionally, in a one-to-one wireless transmission system using a microwave and a millimeter wave band, a directional antenna (parabolic antenna, cassegrain antenna, etc.) having a large antenna gain is usually used. In this wireless transmission system, in order to transmit a large amount of information, two polarized waves in the same frequency band are often used. Polarization refers to a state in which radio waves have a specific vibration direction. Examples of polarization include linear polarization (vertical polarization, horizontal polarization, etc.), circular polarization, and the like.

  For example, large-capacity information transmission can be performed by simultaneously using both vertically polarized waves and horizontally polarized waves at the same frequency. This is because both signals can be distinguished using the orthogonality. Here, the vertical polarization means that the electric field wave vibrates in the vertical direction with respect to the ground plane, and the horizontal polarization means that the electric field wave vibrates in the horizontal direction. Vertically polarized waves and horizontally polarized waves are called “cross-polarized waves” because their planes of polarization are orthogonal. The degree of distinction between both signals is referred to as “cross polarization discrimination”.

  In such a radio transmission system using polarized waves, it is necessary to consider interference due to cross-polarized waves when a sufficiently high cross-polarized wave identification degree cannot be ensured compared to the required CNR. In other words, when the interference due to cross polarization is dominant, it is extremely important to ensure the cross polarization discrimination. In addition, in order to increase the cross polarization discrimination between the vertical polarization and the horizontal polarization, the transmission side transmits two polarizations that are accurately orthogonal to each other, and the reception side accurately determines these two polarizations. It is necessary to receive it.

  When transmitting and receiving two orthogonal polarized waves, a large-scale wireless transmission system such as a satellite communication system or a terrestrial fixed-station communication system uses an integrated antenna or a separate antenna. An antenna placed in a physically accurate positional relationship is used. In such a radio transmission system, the cross polarization interference characteristic as a radio transmission system is largely determined by the degree of cross polarization discrimination of the antenna.

  As an example of a technique for adjusting the polarization plane, a technique for accurately matching the polarization plane of a radio wave to be transmitted with the polarization plane of an opposing reference station is known (see, for example, Patent Document 1). In this method, in order to match the plane of polarization of two transmission signals transmitted by a radio apparatus with the plane of polarization of an opposing reference station, radio signals with two orthogonal polarizations are received from the reference station and propagated between the reference stations. A path matrix is obtained, and based on the element of the propagation path matrix, the angle difference between the polarization plane of the transmission signal transmitted by the wireless device and the polarization plane of the opposite reference station is detected. The amplitude of the transmission signal is adjusted.

  Such a wireless transmission system is provided with a function for accurately aligning the polarization plane, and the polarization plane can be adjusted relatively easily. Also, a compensator that compensates for cross-polarization interference is often used so that the cross-polarization discrimination itself does not become a problem due to the physical shape of the antenna.

  On the other hand, when a satellite broadcast home receiving antenna is used, signals of two orthogonally polarized waves are transmitted from the satellite at a constant level. In this case, the cross polarization discrimination degree in the transmission side satellite is a good value. For this reason, assuming that the two radio waves are orthogonal and can be received at approximately the same level, a method of adjusting the antenna direction and polarization plane based on the received signal level and the measured bit error rate is used. (See, for example, Patent Document 2).

  This method detects the level of the received signal and the bit error rate, thresholds the received signal level, and thresholds the bit error rate to detect the presence or absence of antenna polarization plane angle deviation. In addition, when the level of the received signal is within a predetermined range, it is determined that the signal quality is deteriorated due to the interference signal by the adjacent carrier, and the polarization plane angle deviation is estimated from the D / U ratio using a table. is there.

JP 2010-187068 A JP-A-11-251945

  However, in a simple wireless transmission system using a broadcast program material transmission device (FPU), each time an FPU is used, a transmitter with a transmission antenna and a receiver with a reception antenna are placed on a simple tripod. May be installed in. When transmitting each cross-polarized wave from the transmitting side to the receiving side using separate antennas, not only the cross-polarization discrimination of the antenna itself but also the conditions for installing the antenna (for example, the inclination of the transmitter itself, the receiver The cross polarization interference characteristic is influenced by the inclination of itself.

  An antenna used in such a wireless transmission system is usually covered with a radome or the like for protection from rain or the like, and a waveguide portion serving as an interface with a transmitter can be observed from the outside. it can. The same applies to the receiver. However, in many cases, the polarization plane of the radio wave radiated from or incident on the antenna cannot be determined from the outside.

  As described above, in a simple wireless transmission system using a broadcast program material transmission device (FPU), the antenna itself may be inclined, the transmitter and / or the receiver itself may be inclined, and the antenna itself. Is not very complete. For this reason, it is often impossible to accurately determine the inclination of the polarization plane of the actually transmitted radio wave.

  In such a radio transmission system, there is no guarantee that the cross polarization discrimination on the transmission side is good. For example, in a wireless transmission system that transmits vertical polarization and horizontal polarization using two transmission antennas and two reception antennas, respectively, so that transmission quality (reception power, bit error rate, etc.) is the best, By finely adjusting the polarization planes of the transmission antenna and the reception antenna, a condition that provides the best degree of cross polarization discrimination can be obtained.

  This is based on the premise that when two radio waves are orthogonal, the transmission quality is best if the polarization planes of the transmitting antenna and the receiving antenna are finely adjusted. Applies when

  This fine adjustment is performed on the premise that the inclination angle of each polarization plane itself is unknown because the transmission quality is optimized from the relationship between the two polarizations. Further, when the reception levels of the two polarized waves are different, fine adjustment cannot be performed with high accuracy because the reception level is governed by the influence of radio waves having a high reception level.

  Note that when only one polarization is received and the polarization planes of the transmission antenna and the reception antenna are finely adjusted so that the reception level becomes a peak value (when the direction of the transmission antenna and the reception antenna is adjusted), Even if the polarization plane is slightly rotated by adjustment, the transmission quality hardly changes. For this reason, even when adjustment is performed using one polarized wave, it is difficult to accurately measure the inclination of the polarization plane of the radio wave.

  Accordingly, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide an antenna direction adjustment apparatus and method that can measure the inclination of the polarization plane of the antenna by a simple method. .

  In order to achieve the above object, the antenna direction adjustment apparatus according to claim 1 includes a reception antenna that receives linearly polarized waves, and transmits a transmission that transmits the linearly polarized waves by adjusting a direction determined by an angle of the reception antenna. In the antenna direction adjustment device that measures the inclination of the polarization plane of the reception antenna so as to correspond to the antenna, a receiver that detects the reception power and the bit error rate of the linearly polarized signal received by the reception antenna; A control signal including an angle of the receiving antenna is input, and a direction adjusting unit that adjusts a direction of the receiving antenna based on the control signal, and a control signal including an angle for adjusting the direction of the receiving antenna, A plurality of signals are generated for each different angle, the plurality of control signals are output to the direction adjustment unit, and detected in the direction of the receiving antenna corresponding to each of the plurality of control signals. The received reception power and the bit error rate are input from the receiver, the amount of deterioration of the bit error rate with respect to the amount of decrease in reception power accompanying the change in the angle is calculated, and the angle at which the amount of deterioration of the bit error rate is minimized And a measurement unit that measures the angle as an inclination of the polarization plane.

  The antenna direction adjustment apparatus according to claim 2 is the antenna direction adjustment apparatus according to claim 1, wherein the measurement unit includes a maximum power search unit, a polarization angle fine adjustment unit, and a tilt direction elevation angle fine adjustment unit. When the direction of the receiving antenna is an orthogonal X axis, Y axis, and Z axis, an azimuth angle that rotates in the pan direction with the Z axis as a support axis, an elevation angle that rotates in the tilt direction with the Y axis as a support axis, and an X axis When determined by the polarization angle rotating in the polarization plane direction as a support axis, the maximum power search unit generates a control signal including the arbitrarily set polarization angle and outputs the control signal to the direction adjustment unit, and the direction The control signal including the azimuth and the control signal including the elevation angle when the angle and the elevation angle are respectively changed are generated and output to the direction adjustment unit, and the received power corresponding to the control signal is maximized. Of the receiving antenna A control including a plurality of different polarization angles when the polarization angle fine adjustment unit fine-tunes the polarization angle with reference to the direction of the reception antenna searched by the maximum power search unit. Each of the signals is generated and output to the direction adjustment unit, and the control signal for changing the azimuth angle until the received power is reduced from a maximum value to a predetermined value is generated and output to the direction adjustment unit. Calculating a deterioration amount of a bit error rate with respect to received power corresponding to a control signal for changing an azimuth angle, and specifying a polarization angle that minimizes the deterioration amount of the bit error rate among the plurality of polarization angles; Control including a plurality of different elevation angles when the tilt angle elevation angle fine adjustment unit adjusts the elevation angle with reference to the direction in which the received power becomes maximum when the polarization angle is specified by the polarization angle fine adjustment unit Before each signal is generated A control signal that is output to the direction adjustment unit, generates a control signal that changes the azimuth angle until the received power decreases from a maximum value to a predetermined value, and outputs the control signal to the direction adjustment unit to change the azimuth angle. The amount of degradation of the bit error rate with respect to the received power corresponding to is calculated, and the elevation angle that minimizes the amount of degradation of the bit error rate is specified among the plurality of elevation angles.

  The antenna direction adjustment apparatus according to claim 3 includes a transmission antenna that transmits linearly polarized waves, adjusts a direction determined by an angle of the transmission antenna, and corresponds to a reception antenna that receives the linearly polarized waves. In the antenna direction adjustment device that measures the inclination of the polarization plane of the transmission antenna, a direction adjustment unit that inputs a control signal including the angle of the transmission antenna and adjusts the direction of the transmission antenna based on the control signal; , Generating a plurality of control signals including angles for adjusting the direction of the transmitting antenna for each different angle, outputting the plurality of control signals to the direction adjusting unit, and corresponding to each of the plurality of control signals When the receiving antenna receives the linearly polarized wave transmitted from the transmitting antenna in the direction, the received power and the bead detected by the receiver provided for the receiving antenna are received. Error rate is input, the amount of bit error rate degradation is calculated with respect to the amount of reduction in received power due to the change in angle, the angle at which the bit error rate degradation is minimum is specified, and the angle is And a measuring unit that measures the inclination of the wavefront.

  The antenna direction adjustment apparatus according to claim 4 is the antenna direction adjustment apparatus according to claim 3, wherein the measurement unit includes a maximum power search unit, a polarization angle fine adjustment unit, and a tilt direction elevation fine adjustment unit. When the direction of the transmitting antenna is an orthogonal X axis, Y axis, and Z axis, an azimuth angle that rotates in the pan direction with the Z axis as a support axis, an elevation angle that rotates in the tilt direction with the Y axis as a support axis, and an X axis When determined by the polarization angle rotating in the polarization plane direction as a support axis, the maximum power search unit generates a control signal including the arbitrarily set polarization angle and outputs the control signal to the direction adjustment unit, and the direction The control signal including the azimuth and the control signal including the elevation angle when the angle and the elevation angle are respectively changed are generated and output to the direction adjustment unit, and the received power corresponding to the control signal is maximized. Transmit antenna A control including a plurality of different polarization angles when the polarization angle fine adjustment unit finely adjusts the polarization angle with reference to the direction of the transmission antenna searched by the maximum power search unit. Each of the signals is generated and output to the direction adjustment unit, and the control signal for changing the azimuth angle until the received power is reduced from a maximum value to a predetermined value is generated and output to the direction adjustment unit. Calculating a deterioration amount of a bit error rate with respect to received power corresponding to a control signal for changing an azimuth angle, and specifying a polarization angle that minimizes the deterioration amount of the bit error rate among the plurality of polarization angles; Control including a plurality of different elevation angles when the tilt angle elevation angle fine adjustment unit adjusts the elevation angle with reference to the direction in which the received power becomes maximum when the polarization angle is specified by the polarization angle fine adjustment unit Before each signal is generated A control signal that is output to the direction adjustment unit, generates a control signal that changes the azimuth angle until the received power decreases from a maximum value to a predetermined value, and outputs the control signal to the direction adjustment unit to change the azimuth angle. The amount of degradation of the bit error rate with respect to the received power corresponding to is calculated, and the elevation angle that minimizes the amount of degradation of the bit error rate is specified among the plurality of elevation angles.

  Furthermore, the antenna direction adjustment method according to claim 5 is a receiving antenna that receives linearly polarized waves, a receiver that detects received power and a bit error rate of a linearly polarized signal received by the receiving antenna, and the reception A direction adjustment unit that adjusts the direction of the reception antenna based on a control signal including an angle of the antenna is provided, and a polarization plane inclination of the reception antenna is measured so as to correspond to the transmission antenna that transmits the linearly polarized wave. In the antenna direction adjustment method by the antenna direction adjustment device, a control signal including an angle for adjusting the direction of the reception antenna is generated, and the direction adjustment unit is configured to adjust the direction of the reception antenna based on the control signal. The linearly polarized signal when the linearly polarized wave is received by the receiving antenna in the direction adjusted in the first step and the first step. A second step of inputting a signal power and a bit error rate from the receiver, and for each of a plurality of control signals at different angles, the direction of the receiving antenna is adjusted in the first step, and the second step The received power and the bit error rate are input in the step, the third step for calculating the amount of deterioration of the bit error rate with respect to the amount of decrease in the received power due to the change in angle, and the bit calculated in the third step A fourth step of identifying an angle at which an error rate degradation amount is minimum and measuring the angle as an inclination of the polarization plane.

  The antenna direction adjustment method according to claim 6 includes a transmission antenna that transmits linearly polarized waves, and a direction adjustment unit that adjusts the direction of the transmission antenna based on a control signal including an angle of the transmission antenna. Control including an angle for adjusting the direction of the transmitting antenna in an antenna direction adjusting method by an antenna direction adjusting device that measures the inclination of the polarization plane of the transmitting antenna so as to correspond to a receiving antenna that receives linearly polarized waves A first step of generating a signal and causing the direction adjustment unit to adjust the direction of the transmission antenna based on the control signal, and a straight line transmitted from the transmission antenna in the direction adjusted in the first step A reception power and a bit error rate detected by a receiver equipped with the reception antenna when the reception antenna receives polarization are input. And for each of a plurality of control signals at different angles, the direction of the transmitting antenna is adjusted in the first step, the received power and the bit error rate are input in the second step, and the angle A third step of calculating a deterioration amount of the bit error rate with respect to a reduction amount of the received power due to a change in the above, and an angle at which the deterioration amount of the bit error rate calculated in the third step is minimized, And a fourth step of measuring an angle as an inclination of the polarization plane.

  As described above, according to the present invention, using one of two orthogonal linearly polarized waves, the angle of the antenna having the smallest bit error rate degradation with respect to the received power is obtained, and the polarization plane The inclination was measured. As a result, the inclination of the polarization plane of the antenna can be measured by a simple method.

It is a block diagram which shows the structure of the antenna direction adjustment apparatus of Example 1. FIG. It is a figure explaining the rotating shaft and angle of a receiving antenna. It is a block diagram which shows the structure of a control part. It is a flowchart which shows the process of a control part. It is a flowchart which shows the process of step S402 by the polarization angle fine adjustment part. It is a flowchart which shows the process of step S403 by the tilt direction elevation angle fine adjustment part. It is a characteristic view which shows the relationship between the reception power and bit error rate of each candidate. It is a figure explaining the data stored in the memory by the polarization angle fine adjustment part. It is a figure explaining the data stored in memory by the tilt direction elevation angle fine adjustment part. It is a block diagram which shows the structure of the antenna direction adjustment apparatus of Example 2. FIG.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. The present invention focuses on the property that the amount of deterioration of the bit error rate (BER) of a received signal varies depending on the frequency characteristics of the transmitted signal even with the same received power. When the transmitting antenna and the receiving antenna are facing each other including the plane of polarization, the frequency characteristic of the transmission signal is the best. That is, by using only one side of the linearly polarized wave and searching for the frequency characteristic (the direction of the transmission antenna or the reception antenna) with the smallest amount of degradation of the bit error rate with respect to the reception power, as in Example 1 described later, The polarization plane of the reception antenna can be matched with the polarization plane of the transmission antenna, and the polarization plane of the transmission antenna can be matched with the polarization plane of the reception antenna as in Example 2 described later.

Regarding the change of the bit error rate depending on the frequency characteristics, an example in which a 10 Gbps FPU of 120 GHz band is used has been reported. Refer to the following documents for details.
“Okabe, Tsumochi, Suginoshita,“ Examination of 120 GHz band wireless transmission system for program material transmission ”, 2012 IEICE Communication Society, B-5-95 (2012)”

[Example 1]
First, the antenna direction adjustment apparatus of Example 1 will be described. The antenna direction adjustment apparatus according to the first embodiment is a reception-side apparatus that measures the inclination of the polarization plane when receiving a vertically polarized wave by a receiving antenna, and the amount of bit error rate degradation with respect to the amount of reduction in received power. By specifying the angle of the smallest receiving antenna, the plane of polarization of the receiving antenna is matched with the plane of polarization of the transmitting antenna (the plane of polarization of the vertically polarized wave transmitted from the transmitting antenna).

  FIG. 1 is a block diagram illustrating the configuration of the antenna direction adjusting apparatus according to the first embodiment. The antenna direction adjusting device 1 includes a receiving antenna 11, a receiver 12, a control unit (measuring unit) 13 and a direction adjusting unit 14. Hereinafter, a case where the direction of the transmission antenna 21 installed in the transmitter 22 is fixed and only the vertically polarized wave is transmitted from the transmission antenna 21 will be described.

  The receiving antenna 11 is installed in the receiver 12 and its direction is adjusted by the direction adjusting unit 14. Further, the receiving antenna 11 receives vertically polarized waves that are radio waves from the transmitting antenna 21 installed in the transmitter 22. The direction of the receiving antenna 11 is determined by an azimuth angle, an elevation angle, and a polarization angle, which will be described later.

  The receiver 12 detects the power (reception power) of the reception signal of vertical polarization received by the reception antenna 11, converts it to a baseband signal, quantizes it, performs demodulation processing and decoding processing, and performs a bit error rate. (BER) is detected. Here, the received power is detected using a predetermined calculation formula or the like. The reception power and bit error rate detection methods are known and will not be described in detail here.

  The receiver 12 outputs the detected received power and bit error rate to the control unit 13. Note that the receiver 12 may detect a reception voltage that changes according to the value of the received power instead of the received power, and output the received voltage to the control unit 13.

  The control unit 13 generates a control signal including an angle for adjusting the direction of the reception antenna 11 and outputs the control signal to the direction adjustment unit 14. The control unit 13 also inputs from the receiver 12 received power and a bit error rate when the receiving antenna 11 receives vertical polarization in the direction of the receiving antenna 11 adjusted by the angle included in the control signal. To do.

  The control unit 13 inputs the reception power and the bit error rate, specifies the direction of the reception antenna 11 with the smallest amount of bit error rate degradation with respect to the amount of decrease in reception power, and sets the inclination of the polarization plane of the vertical polarization. taking measurement.

  As described above, it is known that the frequency characteristic changes depending on the direction of the receiving antenna 11, and the deterioration amount of the bit error rate changes depending on the frequency characteristic. Due to this property, when the angle is gradually shifted from the direction of the receiving antenna 11 at which the received power is maximized, the received power is lowered and the bit error rate is deteriorated (increased). In this case, when the angle of the receiving antenna 11 is shifted so that the plane of polarization rotates, the amount of degradation of the bit error rate with respect to the amount of reduction in received power increases. That is, by specifying the direction of the receiving antenna 11 with the least amount of bit error rate degradation relative to the amount of reduction in received power, the angle that is not affected by the rotation of the polarization plane, that is, the inclination of the polarization plane of the vertical polarization is measured. Is done. By adjusting the reception antenna 11 in a direction corresponding to the measured inclination of the polarization plane, the polarization plane of the reception antenna can be matched with the polarization plane of the transmission antenna. Details of the control unit 13 will be described later.

  Here, the rotation axis and angle of the receiving antenna 11 will be described. FIG. 2 is a diagram for explaining the rotation axis and angle of the receiving antenna 11. The receiving antenna 11 is located at the origin of FIG. 2 and can be rotationally driven by the direction adjusting unit 14 with each of three orthogonal fixed axes (X axis, Y axis, and Z axis) as supporting axes. The vertically polarized electric field transmitted from the transmitting antenna 21 oscillates in the Z-axis direction, and the radio wave travels from the plus direction of the X axis to the minus direction. The polarization plane in this case is a plane on which the electric field vibrates.

  When the receiving antenna 11 rotates in the XY plane, which is a plane parallel to the ground plane, that is, when the receiving antenna 11 rotates in the pan direction with the Z axis as a supporting axis, the azimuth angle changes with respect to the reference position. Since the direction of the receiving antenna 11 rotates while maintaining the orthogonal relationship with the electric field of vertical polarization existing only in the Z-axis direction, the plane of polarization is maintained with respect to the rotation of the receiving antenna 11.

  When the receiving antenna 11 rotates in the ZX plane, which is one surface perpendicular to the ground plane, that is, when the receiving antenna 11 rotates in the tilt direction with the Y axis as a support shaft, the elevation angle changes with respect to the reference position. The direction component of the receiving antenna 11 that changes with the rotation of the tilt direction includes the same component as the electric field of the vertically polarized wave that exists only in the Z-axis direction. Therefore, the plane of polarization also changes with the rotation of the receiving antenna 11. End up. For example, when the receiving antenna 11 is rotated in the tilt direction from the state in which the receiving antenna 11 and the transmitting antenna 21 are physically facing each other and the planes of polarization coincide with each other, the relationship that the two antennas are facing each other is As it collapses, the polarization planes of the transmitting antenna 21 and the receiving antenna 11 also do not match.

  When the receiving antenna 11 rotates in the YZ plane, which is another plane perpendicular to the ground plane, that is, when the receiving antenna 11 rotates in the polarization plane direction with the X axis as a supporting axis, the polarization angle changes with respect to the reference position. Since the direction component of the receiving antenna 11 that changes with the rotation of the polarization plane direction includes the same component as the electric field of the vertically polarized wave that exists only in the Z-axis direction, the polarization plane naturally follows the rotation of the reception antenna 11. To change. For example, when the receiving antenna 11 and the transmitting antenna 21 are rotated in the polarization plane direction from the state where the reception antenna 11 and the transmission antenna 21 are physically facing each other, the relationship between the two antennas is maintained. Only the polarization planes of the transmission antenna 21 and the reception antenna 11 change. In such a wireless transmission system, since the transmitting antenna 21 and the receiving antenna 11 are used in a substantially facing relationship, the direction in which the receiving antenna 11 rotates in the polarization plane direction is larger than that in the tilt direction. The influence (degree) of the change of the polarization plane accompanying the rotation is large.

  The control unit 13 of the antenna direction adjusting apparatus 1 shown in FIG. 1 includes an azimuth angle corresponding to a predetermined amount to be rotated from the reference position when the receiving antenna 11 is rotated by a predetermined amount in the pan direction with the Z axis as a support shaft. The control signal is output to the direction adjustment unit 14. Further, when the control unit 13 rotates the reception antenna 11 by a predetermined amount in the tilt direction with the Y axis as a support shaft, the control unit 13 outputs a control signal including an elevation angle corresponding to the predetermined amount to be rotated from the reference position to the direction adjustment unit 14. To do. In addition, when the control unit 13 rotates the reception antenna 11 by a predetermined amount in the polarization plane direction about the X axis as a support shaft, the control unit 13 transmits a control signal including a polarization angle corresponding to the predetermined amount to be rotated from the reference position to the direction adjustment unit. 14 for output.

  Returning to FIG. 1, the direction adjustment unit 14 receives a control signal from the control unit 13, and adjusts the direction of the reception antenna 11 by rotating the reception antenna 11 to an angle included in the control signal. Specifically, the direction adjustment unit 14 rotates the rotation axis (Z-axis) of the azimuth angle in the pan direction so that the azimuth angle included in the control signal matches the azimuth angle of the reception antenna 11. In addition, the direction adjustment unit 14 rotates the rotation axis (Y axis) of the elevation angle in the tilt direction so that the elevation angle included in the control signal matches the elevation angle of the reception antenna 11. In addition, the direction adjusting unit 14 rotates the rotation axis (X axis) of the polarization angle in the polarization plane direction so that the polarization angle included in the control signal matches the polarization angle of the reception antenna 11.

  In addition, the direction adjustment unit 14 outputs the azimuth angle, the elevation angle, and the polarization angle, which are the directions of the reception antenna 11, as rotation amounts of the respective axes to a display (not shown) or the like. In this case, the direction adjustment unit 14 may be configured to manually rotate the reception antenna 11 according to an operator's operation based on the azimuth angle displayed on the display, or automatically based on the control signal. Alternatively, the receiving antenna 11 may be rotated.

(Control unit 13)
Next, the control unit 13 shown in FIG. 1 will be described in detail. FIG. 3 is a block diagram illustrating a configuration of the control unit 13, and FIG. 4 is a flowchart illustrating processing of the control unit 13. As shown in FIG. 3, the control unit 13 includes a maximum power search unit 131, a polarization angle fine adjustment unit 132, a tilt direction elevation angle fine adjustment unit 133, and a memory 134.

3 and 4, the maximum power searching unit 131 of the control unit 13 changes the azimuth angle in the pan direction and the elevation angle in the tilt direction while arbitrarily setting the polarization angle, and the received power is maximized. The direction (azimuth angle θ ₁ , elevation angle θ ₂ , polarization angle θ ₃ ) of the receiving antenna 11 is searched (step S401). Then, the maximum power search unit 131 outputs the search result directions (azimuth angle θ ₁ , elevation angle θ ₂ , polarization angle θ ₃ ) to the polarization angle fine adjustment unit 132.

Accordingly, the direction (azimuth angle θ ₁ , elevation angle θ ₂ , polarization angle θ ₃ ) of the searched reception antenna 11 is determined by the polarization angle fine adjustment unit 132 and the tilt direction elevation angle fine adjustment unit 133 described later. Can be used as a reference angle for obtaining a desired direction by finely adjusting the polarization angle and the elevation angle.

  For example, the maximum power search unit 131 outputs a control signal including an arbitrarily set polarization angle to the direction adjustment unit 14 to adjust the direction of the receiving antenna 11 to the direction of the polarization angle included in the control signal. Then, the maximum power search unit 131 outputs a control signal in which the azimuth angle of the predetermined range and the elevation angle of the predetermined range are changed to the direction adjustment unit 14, and the direction of the reception antenna 11 is the direction of the angle included in the control signal. To adjust.

Then, the maximum power searching unit 131 inputs the received power and the bit error rate when the receiving antenna 11 in the adjusted direction receives the radio wave from the receiver 12 respectively, and the azimuth angle, the elevation angle, the polarization angle, and the received power. And the bit error rate are stored in the memory 134 in association with each other. The maximum power searching unit 131 specifies the azimuth angle corresponding to the maximum received power based on the received power with respect to the predetermined range of azimuth angles and the predetermined range of elevation angles stored in the memory 134, and the received power is maximized. The direction of the receiving antenna 11 (azimuth angle θ ₁ , elevation angle θ ₂ , polarization angle θ ₃ ) is specified. A technique for searching for the direction of the receiving antenna 11 that maximizes the received power is known. For details, see, for example, Patent Document 2 described above.

  Here, referring to FIG. 2, changing the azimuth angle means rotating in the pan direction with the Z axis as a support axis, and therefore the receiving antenna 11 rotates in the XY plane. The XY plane is orthogonal to the direction of the vertical polarization electric field component (Z-axis direction). However, because the radiator portion of the receiving antenna 11 is physically rotated, the polarization plane of the waveguide as the interface is shifted, or the tripod that supports the receiving antenna 11 and the receiver 12 is tilted. For example, the receiving antenna 11 may be installed at an angle. For this reason, the polarization plane of the reception antenna 11 is often at a position rotated from the polarization plane of the original vertical polarization transmitted from the transmission antenna 21. Therefore, the rotational deviation is finely adjusted by the polarization angle fine adjustment unit 132 and the tilt direction elevation angle fine adjustment unit 133.

Returning to FIGS. 3 and 4, the polarization angle fine adjustment unit 132 determines the direction (azimuth angle θ ₁ , elevation angle θ ₂ , polarization angle θ ₃ ) of the reception antenna 11 searched from the maximum power search unit 131 in step S 401. ) And finely adjust the polarization angle in the polarization plane direction based on the direction (azimuth angle θ ₁ , elevation angle θ ₂ , polarization angle θ ₃ ), change the azimuth angle in the pan direction, and bit error The polarization angle θ _3best that minimizes the rate degradation rate is identified (step S402). Details of the polarization angle fine adjustment unit 132 will be described later.

The tilt direction elevation angle fine adjustment unit 133 is a direction (azimuth angle θ ₁ , elevation angle θ ₂ , polarization direction in which the received power becomes maximum when the polarization angle fine adjustment unit 132 specifies the polarization angle θ _3best in step S402. Angle θ _3best ) is input from the polarization angle fine adjustment unit 132, and the elevation angle in the tilt direction is finely adjusted based on the directions (azimuth angle θ ₁ , elevation angle θ ₂ , polarization angle θ _3best ), and the pan direction The azimuth angle is changed, and the elevation angle θ _2best that minimizes the amount of degradation of the bit error rate is specified (step S403). Details of the tilt direction elevation fine adjustment unit 133 will be described later.

Thereby, the control unit 13 determines the direction (azimuth angle θ ₁ , elevation angle θ _2best , polarization angle θ _3best) in which the received power becomes maximum when the tilt direction elevation angle fine adjustment unit 133 specifies the elevation angle θ _{2best in} step S403. ), The control signal including the azimuth angle θ ₁ , the control signal including the elevation angle θ _2best , and the control signal including the polarization angle θ _3best are output to the direction adjustment unit 14 to adjust the receiving antenna 11 to the angle. Can do.

Therefore, the YZ plane (the YZ plane including the Z axis that is the rotation axis in the pan direction of the receiving antenna 11) that minimizes the amount of degradation of the bit error rate in step S403 is the vertical deviation currently transmitted from the transmitting antenna 21. The antenna direction adjustment apparatus 1 on the receiving side can determine that the plane is orthogonal to the wave. That is, by using only vertical polarization and detecting reception power and bit error rate, the optimal direction (azimuth angle θ ₁ , elevation angle θ _{2best) of} the reception antenna 11 corresponding to the transmission antenna 21 to which the vertical polarization is transmitted. , it is possible to obtain the polarization angle _θ 3best), at the receiving side, the polarization angle theta _3Best and elevation theta _2Best the slope of the polarization plane of vertical polarization, it is possible to measure by simple method .

(Polarization angle fine adjustment unit 132)
Next, the polarization angle fine adjustment unit 132 of the control unit 13 shown in FIG. 3 will be described in detail. FIG. 5 is a flowchart showing the process of step S402 by the polarization angle fine adjustment unit 132.

First, the polarization angle fine adjustment unit 132 is directed to the direction of the reception antenna 11 (azimuth angle θ ₁ , elevation angle θ ₂ , polarization angle θ ₃ ) in which the received power searched for by the maximum power search unit 131 is maximum. In order to finely adjust the polarization angle, the polarization angle θ _3-n is set (step S501). Then, the polarization angle fine adjustment unit 132 outputs a control signal including the polarization angle θ _3-n to the direction adjustment unit 14. Thereby, the direction adjusting unit 14 inputs the control signal from the control unit 13 and rotates the receiving antenna 11 to the polarization angle θ _3-n included in the control signal.

n is a positive integer (n = 1, 2,...). In the first process, the polarization angle θ _3-1 = θ ₃ is set. For example, in the second process that moves from step S507 described later, the polarization angle θ _3-2 = θ _3-1 + α is set, and the third In the processing, the polarization angle θ _3-3 = θ _3-1 −α is set, and in the subsequent processing, the polarization angle θ _3-1 = θ ₃ is set as the center so that α changes to the plus side and the minus side. Is set to a polarization angle θ _3-n . α is an angle set in advance to finely adjust the polarization angle.

The polarization angle fine adjustment unit 132 changes the azimuth angle in the pan direction and the elevation angle in the tilt direction in a state where the polarization angle θ _3-n is set, and the direction of the reception antenna 11 (azimuth angle θ ₁ , elevation angle θ ₂ , polarization angle θ _3-n ) (step S502). In the first processing, the polarization angle θ _3-1 = θ ₃ , and the direction (azimuth angle θ ₁ , elevation angle θ ₂ , polarization direction of the reception antenna 11 in which the reception power becomes maximum in step S 401 in FIG. Since the angle θ ₃ ) has already been searched, it can be omitted.

The polarization angle fine adjustment unit 132 outputs a control signal including the azimuth angle θ ₁ and the elevation angle θ ₂ in the direction of the searched reception antenna 11 to the direction adjustment unit 14. Thus, the direction adjustment unit 14 receives the control signal from the control unit 13 rotates the receiving antenna 11 to the azimuth angle theta ₁ and elevation theta ₂ contained in the control signal.

The polarization angle fine adjustment unit 132 sets the azimuth angle θ _1-p in order to change the azimuth angle in the pan direction (step S503). Then, the polarization angle fine adjustment unit 132 outputs a control signal including the azimuth angle θ _1-p to the direction adjustment unit 14 in order to adjust the azimuth angle of the reception antenna 11 to θ _1-p .

p is a positive integer (n = 1, 2,...). In the first process, the azimuth angle θ _1-1 = θ ₁ (the azimuth angle θ ₁ in the direction searched by the maximum power search unit 131) is set. For example, in the second process that moves from step S505 described later, the azimuth angle θ _1-2 = θ _1-1 + β, and in the third process, the azimuth angle θ _1-3 = θ _1-1 −β, and in the subsequent processes, the azimuth angle θ _1-1 = θ ₁ is the center. The azimuth angle θ _1-p is set so as to change to the plus side and the minus side with β as a unit. β is an angle set in advance to change the azimuth angle.

The polarization angle fine adjustment unit 132 determines that the direction of the receiving antenna 11 is the azimuth angle θ _1-p (the azimuth angle set in step S503), the elevation angle θ ₂ (the elevation angle in the direction searched in step S502), and the deviation. The reception power and the bit error rate when the reception antenna 11 receives the radio wave in the state of the wave angle θ _3-n (polarization angle set in step S501) are input from the receiver 12, and the input reception The power and bit error rate are stored in the memory 134 in association with the direction of the receiving antenna 11 (azimuth angle θ _1-p , elevation angle θ ₂ , polarization angle θ _3-n ) (step S504).

FIG. 8 is a diagram for explaining the data stored in the memory 134 in the process of step S504 by the polarization angle fine adjustment unit 132. The data stored in the memory 134 in the process of step S504 by the polarization angle fine adjustment unit 132 corresponds to the elevation angle θ ₂ , the polarization angle θ _3-n, and the plurality of azimuth angles θ _1-p for each candidate. Received power and bit error rate. In step S504, the received power and the bit error rate are stored corresponding to the elevation angle θ ₂ indicating the direction of the receiving antenna 11, the polarization angle θ _3-n, and the azimuth angle θ _1-p .

Returning to FIG. 5, the polarization angle fine adjustment unit 132 compares the received power input from the receiver 12 and stored in the memory 134 in step S <b> 504 with a predetermined value, and determines whether the received power is equal to or lower than the predetermined value. Is determined (step S505). When the polarization angle fine adjustment unit 132 determines in step S505 that the received power is not equal to or less than the predetermined value (step S505: N), the polarization angle fine adjustment unit 132 proceeds to step S503 and sets a new azimuth angle θ _1-p .

When the polarization angle fine adjustment unit 132 determines in step S505 that the received power is equal to or less than the predetermined value (step S505: Y), the repetition power of step S503 to step S505 is used to increase the received power from the maximum value. The direction of the receiving antenna 11 (azimuth angle θ _{1-1, 1-2,...} , Elevation angle θ ₂ , polarization angle θ _3-n ) when lowered to a predetermined value is set as a candidate (step S506). Referring to FIG. 8, for example, candidate 1 is set in the first process in step S506, and candidate 2 is set in the second process.

FIG. 7 is a characteristic diagram showing the relationship between the received power and the bit error rate of each candidate. The horizontal axis indicates the relative power level in the received power, and the vertical axis indicates the bit error rate. Here, the measurement limit of the bit error rate on the vertical axis is 10 ⁻¹⁰ , and below this, it is assumed that no error can be observed. The characteristic of the square mark indicates candidate 1, for example, and the characteristic of the rhombus mark indicates candidate 2, for example. As shown in FIG. 8, each characteristic shows the relationship between the relative power level and the bit error rate corresponding to changes in the azimuth angles θ _1-1 , θ _1-2,. In a candidate 1, a change in the azimuth angle θ _1-p in the pan direction causes the received power to decrease from the maximum value and the characteristics change in the direction of the arrow. In step S505 in FIG. A relative power level and a bit error rate when the received power is determined to be equal to or less than a predetermined value are shown. b indicates the relative power level and the bit error rate in the candidate 2 when it is determined in step S505 in FIG. 5 that the received power is equal to or lower than the predetermined value.

Returning to FIG. 5, the polarization angle fine adjustment unit 132 determines whether or not the number of processes in steps S501 to S506 has reached a predetermined number (step S507), and if the number of processes has not reached the predetermined number. If it is determined (step S507: N), the process proceeds to step S501 to set a new polarization angle θ _3-n .

  When the polarization angle fine adjustment unit 132 determines in step S507 that the number of processing times has reached the predetermined number (step S507: Y), the received power and the bit from the memory 134 for each candidate set in step S506. The error rate is read (step S508).

  The polarization angle fine adjustment unit 132 calculates the deterioration amount of the bit error rate with respect to the reduction amount of the reception power for each candidate (step S509). For example, the polarization angle fine adjustment unit 132 sets the bit error rate when the relative power level is −5 as the deterioration amount of the bit error rate with respect to the reduction amount of the reception power. The bit error rate when the relative power level is −5 corresponds to the bit error rate when it is determined in step S505 in FIG. 5 that the received power is equal to or less than a predetermined value.

The polarization angle fine adjustment unit 132 selects a candidate that minimizes the deterioration amount of the bit error rate with respect to the reduction amount of the reception power calculated in step S509 (step S510). In the example of FIG. 7, the bit error rate at the relative power level −5 in the candidate 1 is 1.5 × 10 ⁻⁴ (see the point a), and the bit at the relative power level −5 in the candidate 2 Since the error rate is 5 × 10 ⁻⁵ , candidate 2 has a smaller amount of bit error rate degradation with respect to the amount of reduction in received power.

The polarization angle fine adjustment unit 132 reads out the candidate polarization angle selected in step S510 from the memory 134, and specifies the read polarization angle as the polarization angle θ _3best (step S511).

In this way, the polarization angle fine adjustment unit 132 finely adjusts the polarization angle θ ₃ that is most susceptible to the influence of the polarization plane, and changes the azimuth angle θ ₁ until the received power decreases from the maximum value to a predetermined value. The amount of degradation of the bit error rate with respect to the amount of decrease in received power is calculated by changing the amount, and the amount of degradation of the bit error rate with respect to the amount of decrease in received power is the smallest among the multiple candidates that have finely adjusted the polarization angle θ ₃ Candidate is selected, and the polarization angle θ ₃ of the candidate is specified as the polarization angle θ _3best . Thereby, the polarization angle θ _3best of the receiving antenna 11 that can receive the vertical polarization transmitted from the transmitting antenna 21 in the optimum direction can be specified.

(Tilt direction elevation fine adjustment unit 133)
Next, the tilt direction elevation angle fine adjustment unit 133 of the control unit 13 shown in FIG. 3 will be described in detail. FIG. 6 is a flowchart showing the process of step S403 by the tilt direction elevation angle fine adjustment unit 133.

First, the tilt direction elevation angle fine adjustment unit 133 sets the elevation angle θ _2-m in order to finely adjust the elevation angle of the receiving antenna 11 (step S601). Then, the tilt direction elevation angle fine adjustment unit 133 outputs a control signal including the elevation angle θ _2-m to the direction adjustment unit 14. Thereby, the direction adjustment unit 14 receives a control signal from the control unit 13 and rotates the reception antenna 11 to an elevation angle θ _2-m included in the control signal.

m is a positive integer (m = 1, 2,...). In the first process, the elevation angle θ _2-1 = θ ₂ (elevation angle θ _{2 in} the direction searched by the maximum power searching unit 131) is set. For example, in the second process that proceeds from step S605 described later, the elevation angle θ _{2− 2} = θ _2-1 + γ, and in the third process, the elevation angle θ _2-3 = θ _2-1 −γ, and in the subsequent processes, the elevation angle θ _2-1 = θ ₂ is the center and γ is added as a unit. The elevation angle θ _2-m is set so as to change to the negative side and the negative side. γ is an angle set in advance for fine adjustment of the elevation angle.

The tilt direction elevation angle fine adjustment unit 133 changes the azimuth angle in the pan direction while maintaining the elevation angle θ _2-m and the polarization angle θ _3best, and the direction (azimuth angle θ _{1) of the} reception antenna 11 that maximizes the reception power. , Elevation angle θ _2−m , polarization angle θ _3best ) (step S602). Note that it is assumed that the receiving antenna 11 is adjusted to the polarization angle θ _3best by step S402 in FIG. 4 and the processing in FIG. In the first process, the elevation angle θ _2-1 = θ ₂ , and the direction (azimuth angle θ ₁ , elevation angle θ) of the reception antenna 11 at which the reception power becomes maximum in step S402 of FIG. 4 and step S502 of FIG. ₂ and the polarization angle θ _3best ) have already been searched and can be omitted.

The tilt direction fine adjustment unit 133 outputs a control signal including the azimuth angle θ ₁ in the direction of the searched reception antenna 11 to the direction adjustment unit 14. Thereby, the direction adjustment part 14 inputs a control signal from the control part 13, and rotates the receiving antenna 11 to the azimuth angle (theta) ₁ contained in a control signal.

The tilt direction elevation angle fine adjustment unit 133 sets the azimuth angle θ _1-p in order to change the azimuth angle in the pan direction (step S603). The tilt direction fine adjustment unit 133 then outputs a control signal including the azimuth angle θ _1-p to the direction adjustment unit 14 in order to adjust the azimuth angle of the receiving antenna 11 to θ _1-p . Step S603 is the same as step S503 shown in FIG.

The tilt direction elevation fine adjustment unit 133 determines the direction of the receiving antenna 11 as the azimuth angle θ _1-p (azimuth angle set in step S603) and the polarization angle θ _3best (identified in steps S402 and FIG. 5 in FIG. 4). The received power and the bit error rate when the receiving antenna 11 receives the radio wave in the state of the polarization angle) and the elevation angle θ _2-m (the elevation angle set in step S601) are input from the receiver 12. The received reception power and bit error rate are stored in the memory 134 in association with the direction of the receiving antenna 11 (azimuth angle θ _1-p , elevation angle θ _2-m , polarization angle θ _3best ) (step S604).

FIG. 9 is a diagram for explaining data stored in the memory 134 in the process of step S604 by the tilt direction elevation angle fine adjustment unit 133. FIG. The data stored in the memory 134 in the process of step S604 by the tilt direction elevation angle fine adjustment unit 133 corresponds to the polarization angle θ _3best , the elevation angle θ _2-m, and the plurality of azimuth angles θ _1-p for each candidate. Received power and bit error rate. In step S604, the received power and the bit error rate are stored corresponding to the polarization angle θ _3best indicating the direction of the receiving antenna 11, the elevation angle θ _2-m, and the azimuth angle θ _1-p .

Returning to FIG. 6, the tilt direction elevation fine adjustment unit 133 compares the received power input from the receiver 12 in step S604 and stored in the memory 134 with the predetermined value, and determines whether the received power is equal to or lower than the predetermined value. Is determined (step S605). When it is determined in step S605 that the received power is not less than or equal to the predetermined value (step S605: N), the tilt direction elevation angle fine adjustment unit 133 proceeds to step S603 and sets a new azimuth angle θ _1-p .

When the tilt direction elevation fine adjustment unit 133 determines in step S605 that the received power is equal to or less than the predetermined value (step S605: Y), the repetition power of steps S603 to S605 is used to increase the received power from the maximum value. The direction of the receiving antenna 11 (azimuth angle θ _{1-1, 1-2,...} , Elevation angle θ _2-m , polarization angle θ _3best ) when lowered to a predetermined value is set as a candidate (step S606). Referring to FIG. 9, for example, candidate 1 is set in the first process in step S606, and candidate 2 is set in the second process.

Returning to FIG. 6, the tilt direction elevation fine adjustment unit 133 determines whether or not the number of processes in steps S601 to S606 has reached a predetermined number (step S607), and if the number of processes has not reached the predetermined number. When it determines (step S607: N), it transfers to step S601 and sets new elevation angle (theta) _2-m .

  When it is determined in step S607 that the number of processing times has reached the predetermined number in step S607 (step S607: Y), the tilt direction elevation fine adjustment unit 133 receives received power and bits from the memory 134 for each candidate set in step S606. The error rate is read (step S608).

  The tilt direction elevation angle fine adjustment unit 133 calculates, for each candidate, a bit error rate deterioration amount with respect to a reception power decrease amount (step S609). For example, like the polarization angle fine adjustment unit 132, the tilt direction elevation angle fine adjustment unit 133 sets the bit error rate when the relative power level is −5 as the degradation amount of the bit error rate with respect to the reduction amount of the received power. To do.

Tilt direction elevation fine adjustment section 133 selects a candidate that minimizes the amount of bit error rate degradation with respect to the amount of reduction in received power calculated in step S609 (step S610). Then, tilt direction elevation fine adjustment unit 133 reads the elevation angle of the candidate selected in step S610 from memory 134, and identifies the read elevation angle as elevation angle θ _2best (step S611).

In this way, the tilt direction elevation angle fine adjustment unit 133 finely adjusts the elevation angle θ ₂ affected by the polarization plane, and changes the azimuth angle θ ₁ until the received power decreases from the maximum value to a predetermined value. Then, the amount of degradation of the bit error rate with respect to the amount of decrease in received power is calculated, and the candidate that minimizes the amount of degradation in bit error rate with respect to the amount of decrease in received power is selected from among a plurality of candidates that finely adjust the elevation angle θ ₂ Thus, the elevation angle θ ₂ of the candidate is specified as the elevation angle θ _2best . Thereby, the elevation angle θ _2best of the receiving antenna 11 that can receive the vertically polarized wave transmitted from the transmitting antenna 21 in the optimum direction can be specified.

As described above, according to the antenna direction adjusting apparatus 1 of the first embodiment provided on the receiving side, the maximum power searching unit 131 of the control unit 13 is set in the direction of the pan direction with the polarization angle arbitrarily set. By changing the elevation angle in the angle and tilt directions, the direction of the reception antenna 11 (azimuth angle θ ₁ , elevation angle θ ₂ , polarization angle θ ₃ ) that maximizes the received power is searched to obtain the reference angle. Then, the polarization angle fine adjustment unit 132 finely adjusts the polarization angle based on the directions searched by the maximum power search unit 131 (azimuth angle θ ₁ , elevation angle θ ₂ , polarization angle θ ₃ ), and pans. By changing the azimuth angle of the direction, the polarization angle θ _3best that minimizes the amount of degradation of the bit error rate is specified. Then, the tilt direction elevation angle fine adjustment unit 133 is the direction (azimuth angle θ ₁ , elevation angle θ ₂ , polarization angle) in which the received power is maximized when the polarization angle θ _3best is specified by the polarization angle fine adjustment unit 132. With reference to θ _3best ), the elevation angle in the tilt direction is finely adjusted, the azimuth angle in the pan direction is changed, and the elevation angle θ _{2best at} which the amount of bit error rate degradation is minimized is specified.

Thus, the direction (azimuth angle θ _{1) of the} reception antenna 11 that can receive the vertical polarization transmitted from the transmission antenna 21 in the optimum direction by using only the vertical polarization and detecting the reception power and the bit error rate. , elevation theta _2Best, polarization angle _θ 3best) can be obtained, at the receiving side, which is the inclination of the polarization plane polarization angle theta _3Best and elevation theta _2Best receiving antenna 11, measuring by a simple technique Is possible.

[Example 2]
Next, the antenna direction adjustment apparatus of Example 2 will be described. The antenna direction adjustment apparatus according to the second embodiment is an apparatus on the transmission side that measures the inclination of the plane of polarization when transmitting vertical polarization from the transmission antenna, and the received power and bit error rate detected on the reception side are measured. Use to identify the transmit antenna's polarization plane (vertical polarization polarization plane transmitted from the transmit antenna) by specifying the angle of the transmit antenna that minimizes the amount of bit error rate degradation relative to the amount of received power reduction. It matches the polarization plane of the antenna.

  FIG. 10 is a block diagram illustrating a configuration of the antenna direction adjusting apparatus according to the second embodiment. The antenna direction adjustment device 2 includes a transmission antenna 21, a transmitter 22, a control unit (measurement unit) 23, and a direction adjustment unit 24. Hereinafter, the case where the direction of the receiving antenna 11 installed in the receiver 12 is fixed and only the vertically polarized wave is transmitted to the receiving antenna 11 will be described.

  The transmission antenna 21 is installed in the transmitter 22, and its direction is adjusted by the direction adjustment unit 24. The transmitter 22 transmits the data to be transmitted from the transmission antenna 21 while forming a vertically polarized wave. The vertically polarized wave transmitted from the transmitting antenna 21 is received by the receiving antenna 11 installed in the receiver 12. The direction of the transmission antenna 21 is determined by the azimuth angle, the elevation angle, and the polarization angle, similarly to the reception antenna 11 described above.

  The control unit 23 outputs a control signal including an angle for adjusting the direction of the transmission antenna 21 to the direction adjustment unit 24. Further, when a radio wave is transmitted in the direction of the transmission antenna 21 adjusted by the angle included in the control signal, the radio wave is received by the reception antenna 11, and the receiver 12 detects the reception power and the bit error rate, The control unit 23 inputs the received power and the bit error rate detected by the receiver 12.

  For example, the control unit 23 inputs the received power and the bit error rate detected by the receiver 12 according to the operation of the operator. The receiver 12 stores the detected received power and bit error rate in a storage medium, and the control unit 23 reads and inputs the received power and bit error rate from the storage medium in accordance with the operation of the operator. Good. In addition, a transmitter (not shown) provided on the receiving side modulates the received power and bit error rate detected by the receiver 12 and transmits the radio wave, and a receiver (not shown) provided on the transmitting side The reception power and the bit error rate may be demodulated by receiving radio waves, and the control unit 23 may input the reception power and the bit error rate demodulated by the receiver.

  The control unit 23 performs the same process as the control unit 13 described above. The control unit 23 inputs the reception power and the bit error rate, specifies the direction of the transmission antenna 21 with the smallest amount of degradation of the bit error rate with respect to the amount of reduction of the reception power, and sets the inclination of the polarization plane of the vertical polarization. taking measurement. The rotation axis and angle of the transmission antenna 21 are the same as the rotation axis and angle of the reception antenna 11 shown in FIG. The difference from FIG. 2 is that vertically polarized radio waves transmitted from the transmitting antenna 21 located at the origin are traveling in the plus direction from the origin.

  The control unit 23 includes a maximum power search unit 131, a polarization angle fine adjustment unit 132, a tilt direction elevation angle fine adjustment unit 133, and a memory 134, similarly to the configuration of the control unit 13 shown in FIG. The same processing as in FIG.

  The direction adjustment unit 24 performs the same processing as the direction adjustment unit 14 described above. The direction adjustment unit 24 receives the control signal from the control unit 23 and adjusts the direction of the transmission antenna 21 by rotating the transmission antenna 21 to an angle included in the control signal.

Thus, the control unit 23, the azimuth angle in the direction received power when tilt direction elevation fine adjustment unit 133 has identified the elevation angle theta _2Best is maximum (azimuth theta _1, elevation theta _2Best, polarization angle _θ 3best) By _{outputting the} control signal including θ ₁ , the control signal including the elevation angle θ _2best , and the control signal including the polarization angle θ _3best to the direction adjusting unit 24, the transmitting antenna 21 can be adjusted to the angle.

Therefore, the YZ plane (the YZ plane including the Z axis that is the rotation axis in the pan direction of the transmission antenna 21) that minimizes the amount of degradation of the bit error rate by the processing of the tilt direction elevation angle fine adjustment unit 133 is The antenna direction adjusting device 2 on the transmission side can determine that the plane is orthogonal to the plane of polarization. In other words, by using only vertical polarization and detecting reception power and bit error rate, the optimal direction (azimuth angle θ ₁ , elevation angle θ _2best , transmission antenna 21 corresponding to reception antenna 11 receiving vertical polarization is _determined . it is possible to obtain the polarization angle _θ 3best), at the transmitting side, the polarization angle theta _3Best and elevation theta _2Best the slope of the polarization plane of vertical polarization, it is possible to measure by a simple technique.

As described above, according to the antenna direction adjustment apparatus 2 of the second embodiment provided on the transmission side, the maximum power searching unit 131 of the control unit 23 is set in the direction of the pan direction with the polarization angle arbitrarily set. By changing the elevation angle in the angle and tilt directions, the direction of the transmission antenna 21 (azimuth angle θ ₁ , elevation angle θ ₂ , polarization angle θ ₃ ) that maximizes the reception power on the reception side is searched to obtain the reference angle. did.

Thereby, the polarization angle fine adjustment unit 132 and the tilt direction elevation fine adjustment unit 133 indicate the directions (azimuth angle θ ₁ , elevation angle θ ₂ , polarization angle θ ₃ ) of the transmission antenna 21 searched by the maximum power search unit 131. As a reference, the polarization angle and the elevation angle can be finely adjusted.

Then, the polarization angle fine adjustment unit 132 of the control unit 23 finely adjusts the polarization angle with reference to the directions (azimuth angle θ ₁ , elevation angle θ ₂ , polarization angle θ ₃ ) searched by the maximum power search unit 131. Adjustment was made to change the azimuth angle in the pan direction, and the polarization angle θ _3best that minimizes the amount of degradation of the bit error rate was specified.

Thereby, the polarization angle θ _3best of the transmission antenna 21 capable of transmitting the vertical polarization received by the reception antenna 11 in the optimum direction can be specified.

Then, the tilt direction elevation angle fine adjustment unit 133 of the control unit 23 is a direction (azimuth angle θ ₁ , elevation angle θ ₂₎ in which the received power becomes maximum when the polarization angle fine adjustment unit 132 specifies the polarization angle θ _3best. , The polarization angle θ _3best ) as a reference, the elevation angle in the tilt direction is finely adjusted, the azimuth angle in the pan direction is changed, and the elevation angle _θ2best that minimizes the amount of bit error rate degradation is specified.

Thereby, the elevation angle θ _2best of the transmission antenna 21 that can transmit the vertical polarization received by the reception antenna 11 in the optimum direction can be specified.

Therefore, the direction (azimuth angle θ ₁ , elevation angle) of the transmission antenna 21 that can transmit the vertical polarization received by the receiving antenna 11 in the optimum direction by using only the vertical polarization and detecting the reception power and the bit error rate. theta _2Best, polarization angle _θ 3best) can be obtained, at the transmitting side, which is the inclination of the polarization plane polarization angle theta _3Best and elevation theta _2Best transmit antennas 21, it can be measured by a simple technique It becomes.

  In the first and second embodiments, the inclination of the reception antenna 11 or the transmission antenna 21 (specifically, the inclination of the direction adjustment units 14 and 24 such as a tripod) is measured as the inclination of the polarization plane, but is transmitted. The polarization plane of the radio wave itself is not measured. In this case, by using an antenna (for example, a standard horn antenna) capable of confirming the polarization plane of the radio wave itself from either the reception antenna 11 or the transmission antenna 21, an absolute value including the inclination of the polarization plane of the radio wave itself can be obtained. It is possible to know the inclination of the polarization plane.

In addition, when the plane of polarization of the reception antenna 11 or the transmission antenna 21 is substantially the same as the plane of polarization of the waveguide interface, the plane of polarization rotates even if the reception antenna 11 or the like is changed in the pan direction in vertical polarization. When the fine adjustment of the elevation angle in the tilt direction is completed, the polarization plane does not rotate so much in the vicinity of the peak (in the vicinity of the specified elevation angle θ _{2best in} the tilt direction). However, if the plane of polarization of the reception antenna 11 or the transmission antenna 21 is considerably deviated from the plane of polarization of the waveguide interface, the plane of polarization rotates when the reception antenna 11 or the like is changed in the pan direction and the tilt direction. Therefore, it becomes difficult to specify an optimum angle by fine adjustment of the polarization angle in the polarization plane direction and fine adjustment of the elevation angle in the tilt direction. The same applies to the case where the plane of polarization rotates in the receiving antenna 11 or the like because the operator cannot recognize it from the outside. In this case, these fine adjustments can be smoothly performed by recognizing the inclination of the polarization plane of the receiving antenna 11 to be used in advance.

  The present invention has been described with reference to the first and second embodiments. However, the present invention is not limited to the first and second embodiments, and various modifications can be made without departing from the technical idea thereof. In the first and second embodiments, the case where only the vertically polarized wave is transmitted from the transmission antenna 21 installed in the transmitter 22 has been described. There is an application when only a wave (for example, a 45-degree inclined polarization) is transmitted. In short, the present invention is applicable when linearly polarized waves are used.

  In the first and second embodiments, the polarization angle fine adjustment unit 132 reads the candidate received power and bit error rate for a predetermined number of times from the memory 134 in steps S508 to S510 illustrated in FIG. The amount of degradation of the bit error rate is calculated for the candidate, and the candidate that minimizes the amount of degradation is selected. On the other hand, instead of Step S506 and Steps S508 to S510, the polarization angle fine adjustment unit 132 compares the deterioration amounts of the two candidates and narrows down the candidates having a small deterioration amount, thereby reducing the deterioration amount to the minimum. May be selected. Specifically, the polarization angle fine adjustment unit 132 calculates the deterioration amount of the bit error rate from the reception power and the bit error rate stored in the memory 134 in the first process before the process of step S507, and 2 The amount of deterioration of the bit error rate is calculated from the received power and the bit error rate stored in the memory 134 in the first processing, the two amounts of deterioration are compared, and the smaller one is set as a candidate. Then, the polarization angle fine adjustment unit 132 compares the degradation amount calculated in the next process with the degradation amount of the set candidate, sets the smaller one as a candidate, and repeats such a process a predetermined number of times. Thus, the candidate that minimizes the deterioration amount is selected. The same applies to the processing of the tilt direction elevation fine adjustment unit 133 shown in FIG.

  Further, in the first and second embodiments, the polarization angle fine adjustment unit 132 repeats the processing of step S501 to step S506 shown in FIG. 5 for the number of processing times. The process may be repeated until it is determined that the bit error rate is equal to or lower than a predetermined value (the bit error rate at a predetermined reception power has decreased to a predetermined value). In this case, in step S507, the polarization angle fine adjustment unit 132 compares the bit error rate when the received power is equal to or lower than the predetermined value in step S505 with the predetermined value, and determines that the bit error rate is not lower than the predetermined value. If it is determined that the bit error rate is equal to or less than the predetermined value, the process proceeds to step S508. As a result, when the bit error rate becomes equal to or lower than the predetermined value, it is not necessary to perform the processes in steps S501 to S506, so that the number of processes can be reduced and the processing load can be reduced. The same applies to the processing of the tilt direction elevation fine adjustment unit 133 shown in FIG.

In the first and second embodiments, the polarization angle fine adjustment unit 132 sets the relative power level as the amount of deterioration of the bit error rate with respect to the amount of decrease in received power for each candidate in step S509 shown in FIG. The bit error rate at -5 is extracted (see FIG. 7), and a candidate that minimizes the bit error rate is selected in step S510. On the other hand, in step S509, the polarization angle fine adjustment unit 132 extracts the relative power level when the bit error rate is 10 ⁻⁵ as the amount of degradation of the bit error rate with respect to the received power for each candidate (FIG. 7), in step S510, a candidate whose relative power level is minimum (negative level is maximum) may be selected. That is, the polarization angle fine adjustment unit 132 may select a candidate that minimizes the received power with respect to the bit error rate, instead of selecting a candidate that minimizes the degradation amount of the bit error rate with respect to the received power. . The same applies to the processing of the tilt direction elevation fine adjustment unit 133 shown in FIG.

  In the first and second embodiments, the polarization angle fine adjustment unit 132 rotates in the YZ plane to finely adjust the polarization angle in the polarization plane direction, and then the tilt direction elevation fine adjustment unit 133 The elevation angle in the tilt direction was finely adjusted by rotating in the plane. In this case, the polarization angle has a larger influence on the change of the polarization plane with respect to the direction of the receiving antenna 11 than the elevation angle, and the large influence angle is finely adjusted first. 5 and the predetermined number of times shown in step S607 in FIG. 6 can be reduced, and the inclination of the polarization plane can be measured with high accuracy. On the other hand, the order of fine adjustment may be reversed. Specifically, the tilt direction fine adjustment unit 133 rotates in the ZX plane to finely adjust the elevation angle in the tilt direction, and then the polarization angle fine adjustment unit 132 performs rotation in the YZ plane. Finely adjust the polarization angle in the polarization plane direction.

DESCRIPTION OF SYMBOLS 1, 2 Antenna direction adjustment apparatus 11 Reception antenna 12 Receiver 13, 23 Control part 14, 24 Direction adjustment part 21 Transmission antenna 22 Transmitter 131 Maximum power search part 132 Polarization angle fine adjustment part 133 Tilt direction elevation angle fine adjustment part 134 memory

Claims (6)

A receiving antenna that receives linearly polarized waves is provided, the direction determined by the angle of the receiving antenna is adjusted, and the inclination of the polarization plane of the receiving antenna is measured so as to correspond to the transmitting antenna that transmits the linearly polarized waves In the antenna direction adjustment device,
A receiver for detecting a reception power and a bit error rate of a linearly polarized signal received by the reception antenna;
A direction adjustment unit that inputs a control signal including an angle of the reception antenna and adjusts a direction of the reception antenna based on the control signal;
A plurality of control signals including angles for adjusting the direction of the receiving antenna are generated for each different angle, the plurality of control signals are output to the direction adjustment unit, and reception corresponding to each of the plurality of control signals is performed. The received power and the bit error rate detected in the direction of the antenna are input from the receiver, the amount of degradation of the bit error rate relative to the amount of reduction of the received power accompanying the change in the angle is calculated, and the degradation of the bit error rate A measurement unit that identifies an angle with a minimum amount and measures the angle as a slope of the polarization plane;
An antenna direction adjusting device comprising: The antenna direction adjusting device according to claim 1,
The measurement unit includes a maximum power search unit, a polarization angle fine adjustment unit, and a tilt direction elevation angle fine adjustment unit,
When the direction of the receiving antenna is an orthogonal X axis, Y axis, and Z axis, an azimuth angle that rotates in the pan direction with the Z axis as a support axis, an elevation angle that rotates in the tilt direction with the Y axis as a support axis, and an X axis When it is determined by the polarization angle that rotates in the direction of the polarization plane as the support axis,
The maximum power search unit includes:
A control signal including the azimuth angle and a control signal including the elevation angle when the control signal including the polarization angle set arbitrarily is generated and output to the direction adjustment unit, and the azimuth angle and elevation angle are respectively changed. Are respectively generated and output to the direction adjustment unit, and the direction of the reception antenna that maximizes the reception power corresponding to the control signal is searched for,
The polarization angle fine adjustment unit is
With reference to the direction of the receiving antenna searched by the maximum power search unit, each of the control signals including a plurality of different polarization angles when finely adjusting the polarization angle is generated and output to the direction adjustment unit, A bit for the received power corresponding to the control signal for changing the azimuth angle by generating a control signal for changing the azimuth angle until the received power drops from a maximum value to a predetermined value and outputting the control signal to the direction adjustment unit. An error rate degradation amount is calculated, and a polarization angle that minimizes the bit error rate degradation amount among the plurality of polarization angles is specified,
The tilt direction elevation fine adjustment unit is
The direction by generating a control signal including a plurality of different elevation angles when adjusting the elevation angle with reference to the direction in which the received power is maximized when the polarization angle is specified by the polarization angle fine adjustment unit. A control signal that is output to the adjustment unit and that changes the azimuth angle until the received power decreases from a maximum value to a predetermined value is generated and output to the direction adjustment unit, and the control signal that changes the azimuth angle An antenna direction adjustment apparatus characterized in that a bit error rate deterioration amount with respect to corresponding received power is calculated, and an elevation angle that minimizes the bit error rate deterioration amount is specified among the plurality of elevation angles. A transmitting antenna that transmits linearly polarized waves is provided, and the direction determined by the angle of the transmitting antenna is adjusted, and the inclination of the polarization plane of the transmitting antenna is measured so as to correspond to the receiving antenna that receives the linearly polarized waves In the antenna direction adjustment device,
A direction adjustment unit that inputs a control signal including an angle of the transmission antenna and adjusts a direction of the transmission antenna based on the control signal;
A plurality of control signals including angles for adjusting the direction of the transmitting antenna are generated for each different angle, the plurality of control signals are output to the direction adjustment unit, and directions corresponding to the plurality of control signals When the receiving antenna receives the linearly polarized wave transmitted from the transmitting antenna, the received power and the bit error rate detected by the receiver provided in the receiving antenna are input, and the reception according to the change in the angle is received. Calculating a bit error rate degradation amount with respect to a power reduction amount, identifying an angle at which the bit error rate degradation amount is minimum, and measuring the angle as an inclination of the polarization plane;
An antenna direction adjusting device comprising: In the antenna direction adjustment device according to claim 3,
The measurement unit includes a maximum power search unit, a polarization angle fine adjustment unit, and a tilt direction elevation angle fine adjustment unit,
When the direction of the transmitting antenna is an orthogonal X axis, Y axis, and Z axis, an azimuth angle that rotates in the pan direction with the Z axis as a support axis, an elevation angle that rotates in the tilt direction with the Y axis as a support axis, and an X axis When it is determined by the polarization angle that rotates in the direction of the polarization plane as the support axis,
The maximum power search unit includes:
A control signal including the azimuth angle and a control signal including the elevation angle when the control signal including the polarization angle set arbitrarily is generated and output to the direction adjustment unit, and the azimuth angle and elevation angle are respectively changed. Are respectively generated and output to the direction adjustment unit, and the direction of the transmission antenna that maximizes the reception power corresponding to the control signal is searched for,
The polarization angle fine adjustment unit is
With reference to the direction of the transmission antenna searched by the maximum power search unit, a control signal including a plurality of different polarization angles when finely adjusting the polarization angle is generated and output to the direction adjustment unit, A bit for the received power corresponding to the control signal for changing the azimuth angle by generating a control signal for changing the azimuth angle until the received power drops from a maximum value to a predetermined value and outputting the control signal to the direction adjustment unit. An error rate degradation amount is calculated, and a polarization angle that minimizes the bit error rate degradation amount among the plurality of polarization angles is specified,
The tilt direction elevation fine adjustment unit is
The direction by generating a control signal including a plurality of different elevation angles when adjusting the elevation angle with reference to the direction in which the received power is maximized when the polarization angle is specified by the polarization angle fine adjustment unit. A control signal that is output to the adjustment unit and that changes the azimuth angle until the received power decreases from a maximum value to a predetermined value is generated and output to the direction adjustment unit, and the control signal that changes the azimuth angle An antenna direction adjustment apparatus characterized in that a bit error rate deterioration amount with respect to corresponding received power is calculated, and an elevation angle that minimizes the bit error rate deterioration amount is specified among the plurality of elevation angles. A receiving antenna that receives linearly polarized waves, a receiver that detects received power and a bit error rate of a linearly polarized signal received by the receiving antenna, and the reception based on a control signal including an angle of the receiving antenna In the antenna direction adjustment method by the antenna direction adjustment device that includes a direction adjustment unit that adjusts the direction of the antenna and measures the inclination of the polarization plane of the reception antenna so as to correspond to the transmission antenna that transmits the linearly polarized wave,
Generating a control signal including an angle for adjusting the direction of the receiving antenna, and causing the direction adjusting unit to adjust the direction of the receiving antenna based on the control signal;
A second step of inputting, from the receiver, received power and a bit error rate of the linearly polarized signal when the linearly polarized wave is received by the receiving antenna in the direction adjusted in the first step; ,
For each of a plurality of control signals at different angles, the direction of the receiving antenna is adjusted in the first step, the reception power and the bit error rate are input in the second step, and the change in the angle is accompanied. A third step of calculating a bit error rate degradation amount with respect to a reception power decrease amount;
A fourth step of identifying an angle at which the amount of bit error rate degradation calculated in the third step is minimized, and measuring the angle as a slope of the polarization plane;
An antenna direction adjusting method comprising: A transmission antenna that transmits linearly polarized waves, and a direction adjustment unit that adjusts the direction of the transmission antenna based on a control signal including an angle of the transmission antenna, so as to correspond to the receiving antenna that receives the linearly polarized waves In the antenna direction adjustment method by the antenna direction adjustment device that measures the inclination of the polarization plane of the transmission antenna,
Generating a control signal including an angle for adjusting the direction of the transmission antenna, and causing the direction adjustment unit to adjust the direction of the transmission antenna based on the control signal;
Received power and bit error rate detected by a receiver equipped with the receiving antenna when the receiving antenna receives linearly polarized waves transmitted from the transmitting antenna in the direction adjusted in the first step. A second step of entering
For each of a plurality of control signals at different angles, the direction of the transmitting antenna is adjusted in the first step, the reception power and the bit error rate are input in the second step, and the change in the angle is accompanied. A third step of calculating a bit error rate degradation amount with respect to a reception power decrease amount;
A fourth step of identifying an angle at which the amount of bit error rate degradation calculated in the third step is minimized, and measuring the angle as a slope of the polarization plane;
An antenna direction adjusting method comprising:

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