JP2020047996A - Radio communication device, program, and radio communication system - Google Patents

Abstract

To provide a radio communication device and the like that prevent transmission quality from deteriorating due to radio wave interference without stopping the operation of a radio communication system.SOLUTION: A radio communication device 11 includes: a first antenna 12 installed such that the polarization plane of a plane wave transmitted and received can be changed; a transmission/reception unit 13 for transmitting/receiving the plane wave to or from a communication opposite party 21 including a second antenna 22 facing the first antenna 12 via the first antenna 12; and a polarization surface control unit 14. The polarization surface control unit 14 determines whether the polarization surface is to be changed on the basis of transmission quality of the plane wave transmitted/received by the transmission/reception unit 13, and instructs the first antenna 12 to change the propagation surface of the first antenna 12 on the basis of the determination.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wireless communication device, a program, and a wireless communication system.

  There is a point-to-point wireless communication system using a plane wave. In a point-to-point wireless communication system, two communication devices each have a directional antenna. The antennas of the two communication devices are fixed to face each other. This allows the two communication devices to communicate bidirectionally.

  Such a wireless communication system may receive unexpected radio interference due to an environmental change after the start of operation. In such a case, there is a concern that the transmission quality of wireless communication is degraded due to the influence of radio wave interference. As a method of reducing the influence of such unexpected radio wave interference, it is conceivable to change the plane of polarization of the plane wave by rotating the polarization of the facing antenna, or to change the antenna azimuth, etc. . As a technique related to this, for example, Patent Literature 1 proposes a method of adjusting the azimuth of an antenna and the like in order to suppress the deterioration of transmission quality due to the influence of radio wave interference.

JP 2015-177483 A

  In the method described in Patent Literature 1, after temporarily stopping two wireless devices, a maintenance person adjusts the azimuth angle and the like of each wireless communication device. That is, there is a problem that the wireless device that has received the radio interference must temporarily stop the operation of the wireless communication system in order to adjust the transmission quality.

  The present disclosure has been made in view of the above-described problem, and provides a wireless communication device or the like that suppresses deterioration of transmission quality due to radio wave interference without stopping operation of the wireless communication system.

  According to one embodiment, a wireless communication apparatus includes a first antenna provided so that a plane of polarization of a plane wave to be transmitted / received can be changed, a communication partner having a second antenna opposed to the first antenna via the first antenna, and It has a transmission / reception unit for transmitting / receiving a plane wave and a polarization plane control unit. The polarization control unit determines whether to change the polarization plane based on the transmission quality of the plane wave transmitted and received by the transmission and reception unit, and changes the polarization plane of the first antenna based on the determination. Is instructed to the first antenna.

  A program according to an embodiment causes a computer to execute a method having the following steps. That is, the method has a determining step of determining whether to rotate the plane of polarization of the plane wave transmitted via the antenna based on the transmission quality of the plane wave received from the communication partner via the antenna. The method further includes the step of instructing the antenna to rotate the plane of polarization of the plane wave based on the determination.

  A wireless communication system according to an embodiment includes a first wireless communication device having a first antenna whose first polarization plane of a plane wave to be transmitted is rotatable around an axis parallel to a transmission direction, and a second antenna of a plane wave to be transmitted. A second wireless communication device having a second antenna whose polarization plane is rotatably installed around an axis parallel to the transmission direction, and a second wireless communication device communicably facing the first wireless communication device. In the above wireless communication system, the first wireless communication device and the second wireless communication device are configured such that an angle formed between the first polarization plane and the second polarization plane is set in advance based on the transmission quality of the plane wave received by one of them. The first polarization plane and the second polarization plane are rotated while maintaining within the range.

  According to the present disclosure, it is possible to provide a wireless communication device or the like that suppresses deterioration of transmission quality due to radio wave interference without stopping operation of the wireless communication system.

FIG. 1 is a schematic configuration diagram of a wireless communication system according to a first embodiment; 5 is a radiation pattern image when the plane of polarization of a plane wave transmitted via the antenna of the wireless communication device according to the first embodiment is rotated. 5 is a flowchart when starting operation of the wireless communication system according to the first exemplary embodiment; 5 is a flowchart of a process in which the wireless communication device according to the first embodiment determines radio interference. FIG. 9 is a schematic configuration diagram of a wireless communication system according to a second embodiment. FIG. 13 is a sequence diagram when the wireless communication system according to the second embodiment performs antenna rotation control. FIG. 9 is a schematic diagram for explaining the influence of the angle of the polarization plane and the interference wave in the wireless communication device according to the second exemplary embodiment; 9 is a flowchart illustrating a process when the wireless communication device according to the second embodiment determines a rotation direction. 9 is a flowchart illustrating a process of the wireless communication device according to the third embodiment.

  The following description and drawings are appropriately omitted and simplified for clarity of explanation. In each of the drawings, the same elements are denoted by the same reference numerals, and repeated description will be omitted as necessary.

<First Embodiment>
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of the wireless communication system according to the first embodiment. The wireless communication system according to the first embodiment is a fixed wireless communication system in which a first wireless communication device 11 and a second wireless communication device 21 installed in base stations separated from each other wirelessly communicate with each other in a point-to-point manner. It is. The wireless communication system according to the present embodiment performs wireless communication using a plane wave. The plane wave is, for example, a microwave or a millimeter wave.

  The first wireless communication device 11 has an antenna 12, a transmission / reception unit 13, and a polarization plane control unit 14 as main components. The second wireless communication device 21 has an antenna 22, a transmission / reception unit 23, and a polarization plane control unit 24 as main components. Since the second wireless communication device 21 has the same configuration as the first wireless communication device 11, each component of the first wireless communication device 11 will be described below, and each component of the second wireless communication device 21 will be described. Description of the configuration is omitted.

  The antenna 12 transmits and receives radio waves for wireless communication with the second wireless communication device 21 that is a communication partner. In the present embodiment, the antenna 12 is a parabolic antenna. The antenna 12 is fixed at a position facing the antenna 22 of the second wireless communication device 21. With such a configuration, the first wireless communication device 11 can transmit and receive radio waves with high directivity, and thus can efficiently communicate with the communication partner.

  In the present embodiment, the antenna 12 transmits and receives a plane wave. The antenna 12 is set to be rotatable around an axis X1, which is the transmission direction of the plane wave transmitted by the antenna 12. The antenna 12 is configured such that the plane of polarization transmitted by the antenna 12 rotates by rotating about the axis X1.

  The antenna 12 has a motor as a driving unit for rotating around the axis X1. Further, the antenna 12 has a rotation angle sensor such as a rotary encoder and a potentiometer, so that the rotation angle can be controlled. In this rotation control, the antenna 12 is set to an initial rotation position. With such a configuration, for example, when the initial setting of the antenna 12 is horizontal polarization and the polarization angle is rotated during operation, the first wireless communication apparatus 11 can easily set the horizontal position, which is the initial position, to the horizontal position. The antenna 12 can be returned to the position of the polarization.

  The transmission / reception unit 13 receives transmission data from a back end, which is an arbitrary device, generates a transmission signal from the received transmission data, and supplies the generated transmission signal to the antenna 12. The transmitting / receiving unit 13 receives a received signal received by the antenna 12, generates received data by demodulating the received signal, and outputs the generated received data to the back end.

  The transmission / reception unit 13 detects the transmission quality of the received signal and supplies information on the detected transmission quality to the polarization plane control unit 14 in addition to the above-described functions. Here, the transmission quality is an index for indicating how faithful information included in a received signal received from an opposite communication partner is with respect to original information. The transmission quality includes information used by the polarization plane controller 14 to determine whether or not to change the polarization angle of the antenna 12. Specifically, the transmission quality includes information on the reception level of a received signal, a bit error rate (BER (Bit Error Rate)), and a carrier-to-noise ratio (C / N or CNR (Carrier to Noise Ratio)). . The information on the reception level, bit error rate, and C / N of the received signal is information indicating the radio field intensity of the received signal, the bit error rate and packet error rate of the transmission data, and the C / N when the received signal is demodulated and reproduced. It may indicate the radio wave intensity, the bit error rate, and the change rate of C / N.

  The polarization control unit 14 determines whether to rotate the polarization plane of the antenna 12 based on the reception level and the bit error rate included in the information on the transmission quality of the reception signal received from the transmission / reception unit 13. That is, the polarization controller 14 monitors, for example, the reception level and the bit error rate, and compares these values with a preset threshold. Then, for example, when the transmission quality is deteriorated as compared with the time when the operation is started, it is determined whether or not to rotate the polarization plane of the antenna 12.

  In addition, when the polarization plane control unit 14 determines to rotate the polarization plane based on the above-described determination, the polarization plane control unit 14 instructs the antenna 12 to rotate. Here, the rotation angle of the polarization plane controller 14 when the antenna 12 is rotated by one instruction is set in advance. In the present embodiment, this rotation angle is referred to as a rotation step. The polarization controller 14 instructs the antenna 12 to rotate at each rotation step. By setting the rotation step in this way, the first wireless communication device 11 can rotate the antenna 12 stably.

The setting of the rotation step will be described with reference to FIG. FIG. 2 is a radiation pattern image when the plane of polarization of a plane wave transmitted via the antenna of the wireless communication apparatus according to the first embodiment is rotated. Radiation pattern L ₁₀ shown in the drawing is an illustration of a radiation characteristic when the rotation control of the polarization plane of the antenna 12. In the figure, the abscissa indicates the inclination difference (rotation angle difference) of the polarization plane between the antenna 12 and the opposing antenna. The vertical axis indicates a reception level (radio wave intensity dBm) which is a signal level received by the facing antenna. The center point where the vertical axis and the horizontal axis intersect is a rotation point in which the inclination difference between the polarization planes of the opposed antennas 12 and 22 is zero degree, and the maintenance person has optimally adjusted the azimuth angle and the like of each wireless communication device. This is the initial position. Radiation pattern L ₁₀ of the antenna 12 for radiating plane wave, the slope of the antenna 90 degrees ± XPD: shows the case the lowest reception level by (Cross Polarization Discrimination cross polarization discrimination) characteristics. Communication using both horizontal and vertical polarizations simultaneously using this XPD characteristic is also common. When the rotation angle difference is ± 90 degrees, the reception level difference becomes the minimum (V _MIN ), and when the inclination difference is zero degrees, the reception level becomes the maximum (V _MAX ). Further, the radiation pattern L ₁₀ is a substantially symmetrical bordering the slope difference zero degree as an image. Thus, the radiation pattern L _10, when the inclination is increased from the tilt zero degrees, although there is a wave on the change rate, the signal level decreases, the inclination difference signal level is minimum at 90 ° ±.

In the above-described radiation pattern, when increasing the inclination from the inclination zero degrees, the inclination difference when the receiving level becomes V _REF was lowered 3dB from V _MAX is A _REF. In the present embodiment, when the reception level is reduced by 3 dB, stable wireless communication that can cover environmental fluctuations becomes difficult. That is, in the wireless communication system 10, the rotation step instructed by the polarization plane control unit 14 is set such that the inclination difference of the polarization plane with the communication partner does not exceed A _REF . The rotation step is set based on communication conditions including environmental fluctuations, variations in rotation control, and the like, in addition to the conditions shown in the figure.

In a situation where the polarization plane is rotated, it is assumed that the wireless communication system 10 is in a state different from an ideal reception state in at least one of the wireless communication devices. Therefore, it is important to consider the margin when setting the rotation step. For example, the rotation step is set to an inclination when the reception level corresponding to 10% of A _REF decreases by 0.3 dB in consideration of the margin. The rotation step when the rotation angle is further increased is set to, for example, about 3 times, which corresponds to 33% of A _REF , that is, the inclination when the reception level is reduced by 1 dB. By setting the rotation step in this manner, the first wireless communication device 11 can rotate the polarization plane while maintaining communication with the communication partner.

  In the first wireless communication apparatus 11 in which the rotation step is set according to the conditions described above, the polarization plane control unit 14 instructs the antenna 12 to rotate in the set rotation step. As a result, the antenna 12 rotates by an angle corresponding to the set rotation step. Note that the rotation of the polarization plane of the antenna 12 is automatically stored in the polarization plane control unit 14. Thereby, the first wireless communication device 11 manages the inclination of the polarization plane of the antenna 12.

  Information about the inclination of the polarization plane of the first wireless communication device 11 is notified to the second wireless communication device 21 as a communication partner by an arbitrary method. Then, the second wireless communication device 21 that has received the notification rotates the antenna 22 to tune the inclination of the polarization plane so as to correspond to the inclination of the polarization plane of the first wireless communication apparatus 11. As described above, the configuration for tuning the inclinations of the polarization planes of the first wireless communication device 11 and the second wireless communication device 21 may be configured to use a communication function so that the communication function can be performed without a user. However, a configuration in which the user performs an operation to tune the inclination of the polarization plane of the second wireless communication device 21 may be employed.

  Next, a process for starting operation of the wireless communication system according to the first embodiment will be described with reference to FIG. FIG. 3 is a flowchart when starting operation of the wireless communication system according to the first embodiment. The flowchart shown in the figure is applied to both the first wireless communication device 11 and the second wireless communication device 21.

  First, the user enters a base station set for the first wireless communication device 11 and a base station set for the second wireless communication device 21, and enters the first wireless communication device 11 and the second wireless communication device. The devices 21 are installed (step S11).

  Next, the user adjusts the antenna positions of the first wireless communication device 11 and the second wireless communication device 21 (step S12). Here, the user installs the antenna 12 included in the first wireless communication device 11 and the antenna 22 included in the second wireless communication device 21 so as to face each other, and then sets the azimuth angle so that good communication is realized. , Elevation angle or polarization angle respectively. By this operation, the state where the inclination difference between the polarization planes of the opposed antennas 12 and 22 is zero degree (initial rotation position) is determined.

  Next, the user activates the first wireless communication device 11 and the second wireless communication device 21 to start the operation of the wireless communication system 10 in a state where the inclination difference of the polarization plane is zero degrees (step S13). . By starting the operation, the first wireless communication device 11 and the second wireless communication device 21 can communicate with each other.

  Next, the user saves the parameters at the start of operation in the first wireless communication device 11 and the second wireless communication device 21, respectively (step S14). Here, the parameters are information on transmission quality of received signals received by the first wireless communication device 11 and the second wireless communication device 21 at the start of operation of the wireless communication system 10, and information on rotational positions of the antennas 12 and 22, respectively. And a rotation step when the antenna 12 and the antenna 22 are rotated.

  Next, the first wireless communication device 11 and the second wireless communication device 21 start monitoring transmission quality (step S15). That is, the polarization control unit 14 of the first wireless communication apparatus 11 monitors the information on the transmission quality received from the transmission / reception unit 13 and determines whether to instruct the antenna 12 to rotate. Similarly, the polarization plane control unit 24 of the second wireless communication device 21 monitors the information on the transmission quality received from the transmission / reception unit 23 and determines whether to instruct the antenna 22 to rotate.

  Next, the first wireless communication device 11 and the second wireless communication device 21 each determine whether or not transmission quality degradation due to radio wave interference has occurred in the received signal (step S16). When it is not determined that the transmission quality deterioration due to the radio wave interference has occurred in the first wireless communication apparatus 11 (Step S16: No), the polarization control unit 14 monitors the information regarding the transmission quality by repeating Step S16. Similarly, if it is not determined that the transmission quality has deteriorated due to radio wave interference in the second wireless communication device 21 (step S16: No), the polarization plane control unit 24 monitors the information on the transmission quality by repeating step S16. I do.

  When determining that the transmission quality has deteriorated due to radio wave interference in the first wireless communication device 11 (step S16: Yes), the polarization controller 14 instructs the antenna 12 to rotate (step S17). . Similarly, when it is determined that the transmission quality has deteriorated due to radio wave interference in the second wireless communication device 21 (step S16: Yes), the polarization controller 24 instructs the antenna 22 to rotate (step S16). Step S17). After instructing the antenna to rotate, the first wireless communication device 11 or the second wireless communication device 21 returns to step S16 and monitors information related to transmission quality.

  Next, the process in which the first wireless communication device 11 and the second wireless communication device 21 determine radio interference will be described in detail with reference to FIG. FIG. 4 is a flowchart of a process in which the wireless communication device according to the first embodiment determines radio interference. The flowchart described below describes processing in the polarization plane controller 14 of the first wireless communication device 11. However, the following flowchart is similarly applied to the polarization plane controller 24 of the second wireless communication apparatus 21.

  First, the polarization control unit 14 determines whether or not the mutual communication state is maintained (step S21). Specifically, for example, the polarization control unit 14 transmits a request signal for requesting a response to the second wireless communication device 21 that is the communication partner via the transmission / reception unit 13 and the antenna 12. Then, when the response signal is received from the second wireless communication device 21 within the preset period, the polarization controller 14 determines that the mutual communication state is maintained. On the other hand, when the response signal is not received from the second wireless communication device 21 within the preset period, the polarization control unit 14 does not determine that the mutual communication state is maintained.

  When it is not determined that the mutual communication state is maintained (Step S21: No), the polarization control unit 14 determines that the wireless communication is in a disconnected state (Step S22). In this case, the polarization plane controller 14 proceeds to the initialization routine. In the initialization routine, for example, the polarization plane control unit 14 instructs to set the inclination of the antenna 12, which is the initial position of the rotation, to zero degrees without using the set rotation step. With such a configuration, in the wireless communication system 10, when the mutual communication state is not maintained, each wireless communication device returns to the initial state, and the communication state can be recovered.

On the other hand, when it is determined that the mutual communication state is maintained (Step S21: Yes), the polarization control unit 14 determines whether or not the transmission quality is degraded after Step S23. Specifically, the polarization control unit 14 starts measuring the bit error rate (BER) included in the information on the transmission quality (step S23). That is, the polarization control unit 14 measures, for example, the BER during a preset period, and determines whether or not the number of bit error occurrences C _TMP during the period is greater than the threshold value C _TH (step S24).

If it is not determined that the bit error occurrence count C _TMP is greater than the preset threshold C _TH (step S24: No), the polarization control unit 14 determines that the transmission quality has not deteriorated (step S25). Therefore, in step S16 shown in FIG. 3, the polarization controller 14 makes a No determination.

On the other hand, when it is determined that the bit error occurrence count C _TMP is greater than the threshold value C _TH (the transmission quality is degraded) (step S24: Yes), the polarization control unit 14 may be receiving radio interference. It is determined that there is a possibility. In this case, the polarization plane controller 14 subsequently determines whether the reception level V _TMP is higher than a preset threshold V _TH (step S26).

When it is not determined that the reception level V _TMP is higher than the threshold value V _TH (step S26: No), the polarization plane controller 14 determines that there is no radio interference. That is, in this case, the deterioration of the transmission quality is not caused by the radio wave interference, but is considered to be caused by, for example, a decrease in the reception level and a decrease in the C / N due to environmental fluctuations such as rainfall fluctuations and fading fluctuations. Thus, the polarization controller 14 waits for a predetermined period to elapse (step S28). Then, the polarization controller 14 returns to step S23, and again compares the number of bit error occurrences C _TMP with the threshold value C _TH .

On the other hand, when it is determined that the reception level V _TMP is higher than the threshold V _TH (step S26: Yes), the bit error rate is higher than the threshold, the transmission quality is degraded, and the reception level of the reception signal is lower than the threshold. If it is high, the transmission quality is degraded due to radio wave interference, and the polarization control unit 14 determines that radio wave interference has occurred (step S27). Therefore, in this case, the polarization plane controller 14 makes a Yes determination in step S16 shown in FIG.

  The first embodiment has been described above. According to the first embodiment, it is possible to detect deterioration of transmission quality due to radio wave interference, instruct rotation of the antenna polarization plane, and restore the initial rotation position when wireless communication is interrupted, without stopping operation of the wireless communication system. Thus, it is possible to provide a wireless communication device or the like having an instruction step of instructing to rotate the antenna polarization plane.

  The wireless communication system 10 according to the first embodiment transmits and receives a plane wave, and does not matter whether it is a horizontally polarized wave or a vertically polarized wave. The antennas 12 and 22 are not limited to parabolic antennas as long as the plane of polarization can be rotated. Further, the antenna 12 and the antenna 22 may have a configuration in which the driver does not have a motor and the user manually drives the antenna.

<Embodiment 2>
Next, a second embodiment will be described. The wireless communication system according to the second embodiment has a specific configuration for rotating the antenna while maintaining that the angle formed by the polarization planes of the opposing antennas is within a preset range. This is different from the first embodiment.

  FIG. 5 is a schematic configuration diagram of the wireless communication system according to the second embodiment. The wireless communication system 100 according to the second embodiment is a fixed wireless communication system in which a first wireless communication device 101 and a second wireless communication device 201 wirelessly communicate with each other in a point-to-point manner.

  The first wireless communication device 101 has, as main components, an antenna 102, a transmitter 103, a receiver 104, a modulator 105, a demodulator 106, a driving unit 107, a control unit 108, and an interface unit 109. The second wireless communication apparatus 201 has an antenna 202, a transmitter 203, a receiver 204, a modulator 205, a demodulator 206, a drive unit 207, a control unit 208, and an interface unit 209 as main components. Since the second wireless communication device 201 has the same configuration as the first wireless communication device 101, each configuration of the first wireless communication device 101 will be described below, and each configuration of the second wireless communication device 201 will be described below. Is omitted.

  The antenna 102 transmits and receives radio waves for wireless communication with the second wireless communication device 201 that is a communication partner. The antenna 102 is fixed at a position facing the antenna 202 of the second wireless communication device 201. The antenna 102 is set to be rotatable around an axis X1 parallel to the transmission direction of the plane wave to be transmitted.

  The transmitter 103 converts the modulated signal received from the modulator 105 into a radio output signal that can be output from the antenna 102 as a plane wave. The transmitter 103 supplies the converted wireless output signal to the antenna 102.

  The receiver 104 receives the radio reception signal received by the antenna 102 and converts the received radio reception signal into a reception reproduction signal. Then, the receiver 104 supplies the converted received reproduction signal to the demodulator 106. Further, receiver 104 generates reception signal level information from the wireless reception signal, and supplies the generated reception signal level information to control section 108. The reception signal level information includes information on the reception level of the reception signal.

  The modulator 105 receives transmission data from the back end via the interface unit 109. Further, modulator 105 receives the own station signal from control section 108 and multiplexes the signal with transmission data. The own-station signal received from the control unit 108 is a signal including a predetermined parameter in the first wireless communication apparatus 101 that is the own station or a request for an opposite communication partner. Modulator 105 multiplexes the transmission data with the own station signal and modulates to generate a modulated signal. The modulator 105 supplies the generated modulation signal to the transmitter 103.

  The demodulator 106 receives the received reproduction signal from the receiver 104, and demodulates the received reproduction signal to generate demodulated data and an opposite station signal. Also, the demodulator 106 generates demodulated data quality information from the generated demodulated data. The demodulated data quality information includes information on the bit error rate and C / N of the demodulated data. The demodulator 106 supplies the generated demodulated data to the interface unit 109. Then, the demodulator 106 supplies the opposite station signal and the demodulated data quality information to the control unit 108.

  The driving unit 107 rotates the antenna 102 in response to an instruction from the control unit 108. When the antenna 102 rotates, the plane of polarization of the antenna 102 rotates. The driving unit 107 has a rotation angle sensor such as a rotary encoder and a potentiometer, in addition to the motor, and can control the rotation angle. Thereby, the driving unit 107 can rotate the antenna 102 according to the set rotation step. The initial position of the rotation of the drive unit 107 is set. Thus, when an instruction to move to the initial position is issued from the control unit 108, the driving unit 107 can move to the set initial position.

  The control unit 108 includes a CPU (Central Processing Unit), a memory, and the like, and controls each component based on the received predetermined information. Specifically, control section 108 receives the received signal level information from receiver 104 and receives the opposite station signal and demodulated data quality information from demodulator 106.

  Further, the control unit 108 determines from the received received signal level information and the demodulated data quality information, for example, whether or not the transmission quality is deteriorated as compared with the time of starting operation, and determines whether to rotate the polarization plane of the antenna 102. Determine whether or not. When it is determined that the polarization plane of the antenna 102 is to be rotated, the control unit 108 supplies a signal regarding a rotation instruction to the driving unit 107. Further, control section 108 supplies modulator 105 with its own signal, which is information or a signal to be transmitted to a communication partner.

  The interface unit 109 is an interface that exchanges data between the first wireless communication device 101 and the back end. Specifically, the interface unit 109 supplies the transmission data received from the back end to the modulator 105, and outputs the reception data received from the demodulator 106 to the back end.

  Note that the transmitter 103, the receiver 104, the modulator 105, the demodulator 106, and the control unit 108 included in the first wireless communication device 101 may be configured as, for example, one semiconductor, or may be configured as one semiconductor. May be constituted by a plurality of electronic components mounted on the substrate. Alternatively, in these configurations, separate hardware may be connected by wire or wirelessly.

  The main configuration of the first wireless communication device 101 has been described above. With such a configuration, the wireless communication system 100 allows the antenna 102 and the antenna 102 while maintaining that the angle formed by the polarization plane of the antenna 102 and the polarization plane of the antenna 202 is within the range of a preset inclination difference. The antenna 202 is rotated.

Next, an example of antenna rotation control performed by the wireless communication system 100 will be described with reference to FIG. FIG. 6 is a sequence diagram when the wireless communication system according to the second embodiment performs antenna rotation control. Here, the wireless communication system 100 is in operation, and the deterioration of transmission quality due to radio wave interference has been detected in the received signal received by the first wireless communication apparatus 101, so that the control unit 108 has determined that the antenna is to be rotated. (Step S17 in FIG. 3). Further, here, the first wireless communication apparatus 101 rotates the plane of polarization of the antenna by the rotation angle A _TGT which is a rotation step in order to reduce signal deterioration due to radio wave interference. With respect to the angle information at the start of operation, the rotation angle A _TGT is controlled to increase in the direction of +90 degrees in the case of clockwise increase direction control, and is increased in the direction of -90 degrees in the case of counterclockwise control. The increase / decrease control is controlled for each rotation angle A _{TGT in} a range from degrees to +90 degrees. The rotation angle A _{TGT corresponding} to the rotation step increases / decreases at each rotation control step. Angle information is collected by a rotation angle sensor or the like, and it is confirmed that the rotation angle A _TGT has been reached. Further, the rotation angle information (A _CRT in FIG. 8 described later) with respect to the rotation angle (zero degree) of the initial position at the start of operation is updated in the memory.

First, the first wireless communication apparatus 101 determines to rotate the antenna by monitoring the transmission quality received from the received signal, and starts antenna rotation control (step S30). Here, the first wireless communication apparatus 101 determines to rotate the antenna by the rotation angle A _TGT .

Note that the rotation angle A _TGT is not limited to a relative angle, and may be an absolute angle from an initial rotation position (zero degrees). Further, the rotation angle A _TGT of the rotation step value may be a preset constant value, may be a value corresponding to an actually measured value of the XPD characteristic of the antenna as shown in FIG. It may be determined by a value according to the degree of deterioration of transmission quality (BER or C / N). As an example according to the degree of deterioration of the transmission quality, in a state where the degree of deterioration is small at about the BER threshold (for example, about 1E-5), the rotation step value is reduced and an error 10 times as large as the BER threshold occurs. When the degree of deterioration of the transmission quality is large (for example, about 1E-4), the control is such that the rotation step value is increased to twice or three times the rotation angle _{ATGT in} order to increase the rotation speed.

  Next, the first wireless communication device 101 transmits a request signal for requesting the second wireless communication device 201 to rotate the antenna (step S31). Specifically, when generating a request signal, control section 108 of first wireless communication apparatus 101 supplies the generated request signal to modulator 105 as a local station signal. The modulator 105 multiplexes the own-station signal (request signal) received from the control unit 108 with the transmission data received from the back end, modulates the multiplexed signal, and generates a modulated signal. The modulated signal in which the request signal has been multiplexed in this manner is transmitted to the second wireless communication apparatus 201 that is the communication partner via the transmitter 103 and the antenna 102.

  Next, the second wireless communication device 201 that has received the request signal transmits a signal notifying the angle of its own antenna 202 to the first wireless communication device 101 together with a response signal to the request (step S32). Specifically, the request signal transmitted from first wireless communication apparatus 101 is supplied to demodulator 206 via antenna 202 and receiver 204. The demodulator 206 demodulates the received modulated signal, and supplies the control unit 208 with the own station signal (request signal) of the first wireless communication apparatus 101 included in the modulated signal. Upon receiving the request signal, control unit 208 generates a response signal for notifying that the request signal has been received. Further, the control unit 208 reads the angle information of the antenna 202 stored in advance, and supplies the read angle information and the generated response signal to the modulator 205. Subsequent processing is the same as in the case of the above-described first wireless communication apparatus 101, and a description thereof will be omitted.

  Next, when receiving the response signal from the second wireless communication device 201, the first wireless communication device 101 instructs the driving unit 107 to rotate the antenna 102 (step S33). At this time, the control unit 108 reads the angle information of its own antenna 102 stored in advance. Then, the read angle information of the antenna 102 is compared with the angle information of the antenna 202 received from the second wireless communication apparatus 201, and the polarization planes of the two substantially match (the antenna rotation angle difference between the opposing antennas is zero degree). ). Here, “substantially coincide” means that variation in operation, measurement accuracy, and the like are allowed, and that, for example, an angle shift of one-fourth or less of the rotation step is allowed. If the two polarization planes do not coincide with each other, the control unit 108 instructs the drive unit 107 to perform the rotation step by instructing the angle corrected for the generated angle shift. If the two polarization planes match, the control unit 108 instructs the drive unit 107 to perform a preset rotation step.

  Next, the control unit 108 transmits an antenna rotation notification signal to the second wireless communication device 201 (Step S34). The antenna rotation notification signal includes a signal for notifying rotation of its own antenna 102 and a signal for requesting rotation of antenna 202 of second wireless communication apparatus 201.

  Next, upon receiving the antenna rotation notification signal, the control unit 208 of the second wireless communication device 201 instructs the driving unit 207 to rotate the antenna 202 (Step S35). The control unit 208 instructs the drive unit 207 to rotate in a rotation step.

  Next, when the rotation of the antenna 202 is completed, the control unit 208 transmits a rotation completion notification signal, which is a signal for notifying the rotation completion, to the first wireless communication apparatus 101 (step S36).

Next, when the first wireless communication device 101 receives the rotation completion notification signal from the second wireless communication device 201, the rotation angle A _REQ by the processing performed after starting the rotation control reaches the determined rotation angle A _TGT . It is determined whether or not it has been performed (step S37).

When it is not determined that the rotation angle A _REQ is equal to or _larger than the determined rotation angle A _TGT (step S37: No), the first wireless communication device 101 returns to step S31 to further rotate the antenna 102, and further switches the antenna 102 Perform rotation processing. On the other hand, when determining that the rotation angle A _REQ is equal to or greater than the determined rotation angle A _TGT (step S37: Yes), the first wireless communication apparatus 101 ends the antenna rotation control.

  As described above, by performing processing while monitoring the rotation angles of the antennas of the first wireless communication apparatus 101 and the second wireless communication apparatus 201, the wireless communication system 100 rotates the polarization plane while maintaining the communicable state. be able to. Step S33 and step S34 may be performed simultaneously, or step S34 may be performed first.

  Note that, when the rotation control ends, the first wireless communication apparatus 101 performs a process of determining whether or not the transmission quality has deteriorated due to the radio wave interference again, as described with reference to FIG. Then, when it is determined that the deterioration of the transmission quality has been suppressed, the process of determining whether or not the deterioration of the transmission quality has occurred due to the new radio wave interference is repeated without performing the control of rotating the antenna.

  Next, the above-described rotation control will be further described with reference to FIG. FIG. 7 is a schematic diagram for explaining the influence of the angle of the polarization plane and the interference wave in the wireless communication apparatus according to the second embodiment.

The schematic diagram of FIG. 7 will be described below. In the figure, the circle L _20, if there is no radio interference, shows the relationship between the rotation angle of the case of rotating while synchronizing the antenna 102 and the antenna 202 and the reception level. Zero degree in the figure indicates the antenna angle zero degree at the initial position at the start of operation. Further, the radius at which the arrow V20 circle L ₂₀ shows the reception level of the received signal. That is, in this example, when the antenna 102 and the antenna 202 are rotated while being synchronized with each other, the maximum reception level when the antenna 102 is not affected by the interference wave is constant (V ₂₀ ) regardless of the rotation angle. Here, the reception level originally fluctuates due to fluctuations in the environment of the propagation path or the like, but such fluctuations are omitted from the description.

Rotation angle of the antenna 102, the position A21 that intersects the dashed line extending from the center of the circle L ₂₀ upward indicates the initial position of the operation start time of the antenna 102 (angle 0 °). As shown in the figure, the rotation direction of the antenna 102 is defined as a plus direction when the antenna 102 is rotated clockwise rightward from the initial position, and a minus direction when the antenna 102 is rotated counterclockwise leftward. I do. Position A _{+ 90} is the reception level when antenna 102 is rotated 90 degrees in the plus direction from the initial position. Similarly, the position A- ₉₀ is a reception level when the antenna 102 is rotated 90 degrees in the minus direction from the initial position. For example, in the control range in which the antenna polarization plane control is performed in the range from the position A _{+ 90} to the position A− ₉₀ , increase / decrease control is performed while comparing.

Curve W which exists inside the circle L ₂₀ represents the signal level of the interference wave generated after the start of operation, in which qualitatively shown in accordance with the rotation angle of the antenna 102. For example, assuming that interference waves due to overreach occur when adjacent same wireless communication systems operate on the same polarization plane, the interference waves have a flat shape that is long in the vertical direction and short in the horizontal direction, as shown in the figure. ing. This is a state in which the interference wave is affected at the operation initial value of the angle of zero degree (position A ₂₁ ). This interference is greatly affected at position A ₂₁ near illustrates an example in which the influence is small tendency toward the A ₊₉₀ or A _-90.

Arrow _{V 21} from the position _{A 21} extending to the center of the circle _{L 20} is an image of the received signal at position _{A 21.} The length of the arrow V ₂₁ is about half of the arrow V ₂₀ is the receiving level in the absence of radio interference. That is, when there is no radio interference should receive level is V _20, since the radio wave interference occurs, when the antenna 102 is in position A _21, the arrows V ₂₁ the received signal is deteriorated It is in the state of. Here, the arrows V ₂₁ the transmission quality has deteriorated, the control unit 108 is assumed to be level to determine to rotate the antenna 102. Therefore, the control unit 108, for example, determines to rotate the antenna 102 from the position _{A 21} to the plus direction.

As described with reference to FIG. 6, the first wireless communication apparatus 101 controls the rotation of the antenna 102 and the antenna 202 of the communication partner. Here, the result of the rotation control, the antenna 102 has been rotated to the position A ₂₂ and. Arrow _{V 22} shows the state of the received signal at position _{A 22.} Although the arrow V ₂₂ are affected by radio interference, it is assumed the controller 108 is not at a level that determines to rotate the antenna. In this case, the first wireless communication device 101 terminates the antenna rotation control rotated to the position _{A 22} and antenna 102 from the position _{A 21.} Thus, the wireless communication system 100 rotates the antenna to a position where the influence of radio wave interference is relatively small. Thereby, the wireless communication system 100 can automatically suppress the influence of radio wave interference due to an environmental change or the like occurring after the operation. In addition, since the rotation angles of both antennas are controlled at each preset rotation step, the wireless communication system 100 can automatically suppress the influence of radio wave interference without stopping operation.

Next, an example of a process for determining a rotation direction in the above-described rotation control will be described with reference to FIGS. 7 and 8. In this embodiment, the antenna 102 is set so as to rotate the control at the position _A rotation angle _A range of _TGT 180 degrees in the range of ₊₉₀ from the position _{A -90.} The reason for this setting is that the antenna 102 receives a plane wave, and the characteristics of the plane wave tend to be so-called two-fold symmetrical with respect to the position rotated by 180 degrees. With such a configuration, the wireless communication system 100 can efficiently reduce the influence of the interference wave. Further, with such a configuration, physical signal wiring to the antenna 102 is facilitated, excessive bending can be prevented, and a rotation control error that occurs when the antenna rotation angle is rotated infinitely can be suppressed.

7, referred to as increasing control control to rotate the antenna in a direction away from the position A ₂₁ is the initial position. Also referred to as reduction control the control to rotate the antenna in a direction approaching to the position A ₂₁ is the initial position. In the present embodiment, wireless communication system 100 controls the position of the antenna so as not to be separated from the initial position (position A ₂₁ ) by 90 degrees or more. For example, when having reached the position A ₊₉₀ by increasing control when finishing the antenna rotation control (at S37 in FIG. 6 Yes), it starts controlling the direction from next position A ₂₁ (decreasing direction). Also, further, beyond the position A _21, performs increase control toward the position A _-90, it will control to find a rotational position which is not influenced by the interference waves.

  FIG. 8 is a flowchart illustrating processing when the wireless communication device according to the second embodiment determines a rotation direction. The flowchart of FIG. 8 illustrates details of step S33 in the sequence diagram of FIG.

In FIG. 8, the control unit 108 reads its own antenna angle _ACRT and antenna rotation angle _ATGT stored in advance (step S41). The own antenna angle _ACRT is the antenna angle after the rotation is controlled by the rotation angle _ATGT of the rotation step. After the rotation control, when the control value obtained by adding A _CRT and A _TGT exceeds 90 degrees, that is, when | A _CRT + A _TGT |> 90, the rotation control direction is changed. This is the angle range of the rotation control (position A- ₉₀ to position A _{+ 90} ) and prevents infinite rotation control of the antenna rotation control. After the control is completed, the memory value of the A _CRT is updated to the added value of A _CRT + A _TGT .

  Next, the control unit 108 determines whether or not the response signal received from the second wireless communication device 201 includes an initialization request (step S42). When the response signal includes the initialization request (Step S42: Yes), the control unit 108 proceeds to an initialization routine. In the initialization routine, for example, the control unit 108 instructs to set the angle of the antenna 102 to zero degrees without using the set rotation step. On the other hand, when the response signal does not include the initialization request (Step S42: No), the control unit 108 proceeds to Step S43.

Next, the control unit 108 performs a process of selecting a direction in which the antenna is rotated. That is, the control unit 108 determines whether or not the angle obtained by adding the rotation angle _ATGT to the latest antenna angle _ACRT stored in the memory exceeds the control range (step S43). Specifically, for example, it is determined whether or not a value obtained by adding the rotation angle A _TGT to its own antenna angle A _CRT exceeds 90 degrees.

If the value obtained by adding its own antenna angle _{A CRT} to the rotation angle _{A TGT} is determined to exceed 90 degrees (step S43: Yes), the angle of the antenna after rotation will be greater than 90 degrees from the initial position. Therefore, the control unit 108 performs reduction control so that the angle of the antenna after rotation does not exceed 90 degrees from the initial position. In this case, the control unit 108 performs the rotation control as the decrease control after reversing the sign of the rotation angle _ATGT . After the rotation control, the data in the memory of the antenna angle A _CRT after the rotation control is updated (step S44).

On the other hand, if the value obtained by adding the rotation angle _{A TGT} to its own antenna angle _{A CRT} is not determined to exceed 90 degrees (step S43: No), the angle of the antenna after rotation will not exceed 90 degrees from the initial position. Therefore, the control unit 108 performs rotation control in a direction according to the read value. After the rotation control, the data in the memory of the antenna angle A _CRT after the rotation control is updated (step S45).

  The second embodiment has been described above. According to the second embodiment, there is provided a wireless communication device or the like that suppresses deterioration of transmission quality due to radio wave interference without stopping operation of a wireless communication system and without a user performing a work of connecting an antenna. can do.

<Embodiment 3>
Next, a third embodiment will be described. Embodiment 3 is different from Embodiment 2 in that the radiation patterns of the opposed antennas are different. That is, the radiation pattern of the antenna 102 of the first wireless communication device 101 and the radiation pattern of the antenna 202 of the second wireless communication device 201 according to the third embodiment are different. Therefore, the rate of change of the signal level when the polarization plane is rotated is different. Therefore, in the third embodiment, when starting operation, the rotation step determined by the antenna 102 and the rotation step determined by the antenna 202 are compared, and a smaller rotation step is selected, and the selected rotation step is performed. Steps are shared by both parties.

  FIG. 9 is a flowchart illustrating processing of the wireless communication device according to the third embodiment. The flowchart shown in FIG. 9 differs from the flowchart shown in FIG. 3 in the processing between step S13 and step S15. Hereinafter, step S51 and step S53 will be described.

  After step S13, the first wireless communication device 101 and the second wireless communication device 201 detect their own parameters at the start of operation, respectively (step S51). Here, the first wireless communication device 101 and the second wireless communication device 201 have a preset rotation step based on the radiation pattern of the antenna of each.

  Next, the first wireless communication device 101 and the second wireless communication device 201 share their parameters by transmitting their own parameters and receiving the parameters of the communication partner (step S52). The parameters shared here include information on the radiation pattern or information on the rotation step.

  Next, the first wireless communication apparatus 101 and the second wireless communication apparatus 201 compare the shared parameters with each other, and select a smaller rotation step as a result of the comparison. Then, the selected rotation step is determined as an operation parameter (step S53). After determining the operation parameters, the first wireless communication device 101 and the second wireless communication device 201 continue operation according to the determined operation parameters.

  Although the third embodiment has been described above, the processing of the wireless communication system according to the third embodiment is not limited to this. For example, only one of the wireless communication devices determines the operation parameter. By notifying the operation parameter determined by one to the other, the rotation step of both may be determined. With such a configuration, the wireless communication apparatus according to the third embodiment does not stop the operation of the wireless communication system even when the wireless communication apparatus has antennas having different sizes and characteristics, and allows the user to operate the wireless communication system. It is possible to provide a wireless communication device or the like that suppresses deterioration of transmission quality due to radio wave interference without performing an operation of connecting an antenna.

  It should be noted that the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist.

  Some or all of the above embodiments may be described as in the following supplementary notes, but are not limited thereto.

(Appendix 1)
A first antenna whose polarization plane is rotatable around an axis parallel to the transmission direction of the plane wave to be transmitted;
A transmitting / receiving unit that transmits or receives a plane wave with a communication partner having a second antenna facing the first antenna via the first antenna;
A polarization control unit that determines whether to rotate the polarization plane based on the transmission quality of the plane wave received by the transmission / reception unit, and instructs the first antenna to rotate the polarization plane based on the determination. When,
A wireless communication device comprising:

(Appendix 2)
A driving unit that rotates the first antenna around an axis parallel to a plane wave transmission direction to rotate the polarization plane;
The wireless communication device according to claim 1, wherein the polarization control unit instructs the driving unit to rotate the first antenna.

(Appendix 3)
The radio wave according to claim 1 or 2, wherein the polarization plane control unit instructs to change the polarization plane at every rotation step having a preset angle, with respect to a rotation angle at which the first antenna rotates. Communication device.

(Appendix 4)
The wireless communication device according to claim 3, wherein the rotation step instructed by the polarization plane control unit is set based on a relationship between an angle when the polarization plane is rotated and a radio wave intensity of a received plane wave.

(Appendix 5)
The polarization plane control unit according to any one of Supplementary notes 1 to 4, wherein at least one of a signal level of the received plane wave, a bit error rate of the received plane wave, or a carrier to noise ratio is processed as the transmission quality. Wireless communication device.

(Appendix 6)
The polarization plane control unit instructs to rotate the polarization plane while monitoring the angle formed by the first polarization plane of the plane wave transmitted by the first antenna and the second polarization plane of the plane wave transmitted by the second antenna. The wireless communication device according to any one of supplementary notes 1 to 5, wherein

(Appendix 7)
7. The wireless communication apparatus according to claim 6, wherein the polarization control unit notifies the communication partner of rotating the first polarization plane and instructs the first antenna to rotate the first polarization plane.

(Appendix 8)
The supplementary note 7, wherein the polarization control unit receives permission from the communication partner to rotate the first polarization plane, and instructs the first antenna to rotate the first polarization plane according to the permission. The wireless communication device according to claim 1.

(Appendix 9)
The polarization plane control unit, when the second polarization plane of the communication partner is rotatably installed,
The wireless communication device according to any one of Supplementary Notes 6 to 8, which requests the communication partner to rotate the second polarization plane so as to correspond to the rotation of the first polarization plane.

(Appendix 10)
The polarization plane control unit, when the second polarization plane of the communication partner is rotatably installed,
When the communication partner requests to rotate the first polarization plane, the first polarization plane is rotated according to the request, and after the rotation is completed, the communication partner is notified that the request has been responded to. 10. The wireless communication device according to any one of supplementary notes 6 to 9, wherein

(Appendix 11)
The rotation step instructed by the polarization plane control unit,
A first angle determined based on a relationship between an angle when the plane of polarization is rotated in the first antenna and the radio wave intensity of the received plane wave;
Of the second angle determined based on the relationship between the angle when the plane of polarization is rotated in the second antenna and the radio wave intensity of the received plane wave,
4. The wireless communication device according to claim 3, wherein the wireless communication device is set based on a smaller one of the angles.

(Appendix 12)
Based on the transmission quality of the plane wave received from the communication partner via the antenna, a determination step of determining whether to rotate the plane of polarization of the plane wave transmitted via the antenna,
Instructing the antenna to rotate the plane of polarization of the plane wave based on the determination.

(Appendix 13)
A first wireless communication device having a first antenna in which a first polarization plane of a plane wave to be transmitted is rotatably installed around an axis parallel to a transmission direction;
A second wireless communication device having a second antenna in which a second plane of polarization of the plane wave to be transmitted is rotatably installed around an axis parallel to the transmission direction, and facing the first wireless communication device in a communicable manner; ,
The first wireless communication device and the second wireless communication device each have a range in which an angle formed by the first polarization plane and the second polarization plane is set based on transmission quality of a plane wave received by one of the first and second wireless communication apparatuses. A wireless communication system for rotating the first and second polarization planes while maintaining the distances within the range.

(Appendix 14)
The wireless communication device according to claim 3, wherein the rotation step instructed by the polarization plane control unit is set based on a measured value of the cross polarization discrimination of the first antenna or the second antenna.

(Appendix 15)
The wireless communication device according to claim 3, wherein the rotation step instructed by the polarization plane control unit is set according to a degree of deterioration of transmission quality of the plane wave.

10, 100 Wireless communication system
12, 22, 102, 202 antenna
13, 23 Transceiver
14, 24 Polarization plane controller
103, 203 Transmitter
104, 204 Receiver
105, 205 Modulator
106, 206 Demodulator
107, 207 Drive part
108, 208 Control unit
109, 209 Interface section

Claims (10)

A first antenna whose polarization plane is rotatable around an axis parallel to the transmission direction of the plane wave to be transmitted;
A transmitting / receiving unit that transmits or receives a plane wave with a communication partner having a second antenna facing the first antenna via the first antenna;
A polarization control unit that determines whether to rotate the polarization plane based on the transmission quality of the plane wave received by the transmission / reception unit, and instructs the first antenna to rotate the polarization plane based on the determination. When,
A wireless communication device comprising: A driving unit that rotates the first antenna around an axis parallel to a plane wave transmission direction to rotate the polarization plane;
The wireless communication device according to claim 1, wherein the polarization plane control unit instructs the driving unit to rotate the first antenna. The said polarization plane control part instruct | indicates changing the said polarization plane for every rotation step which has a preset angle about the rotation angle which is the angle which the said 1st antenna rotates. Wireless communication device. The wireless communication device according to claim 3, wherein the rotation step instructed by the polarization plane control unit is set based on a relationship between an angle when the polarization plane is rotated and a radio wave intensity of a received plane wave. The polarization plane control unit instructs to rotate the polarization plane while monitoring the angle formed by the first polarization plane of the plane wave transmitted by the first antenna and the second polarization plane of the plane wave transmitted by the second antenna. The wireless communication device according to claim 1. The wireless communication device according to claim 5, wherein the polarization plane control unit notifies the communication partner of rotating the first polarization plane and instructs the first antenna to rotate the first polarization plane. . 7. The polarization plane control unit receives permission from the communication partner to rotate the first polarization plane, and instructs the first antenna to rotate the first polarization plane according to the permission. A wireless communication device according to claim 1. The rotation step instructed by the polarization plane control unit,
A first angle determined based on a relationship between an angle when the plane of polarization is rotated in the first antenna and the radio wave intensity of the received plane wave;
Of the second angle determined based on the relationship between the angle when the plane of polarization is rotated in the second antenna and the radio wave intensity of the received plane wave,
The wireless communication device according to claim 3, wherein the wireless communication device is set based on any smaller angle. Based on the transmission quality of the plane wave received from the communication partner via the antenna, a determination step of determining whether to rotate the plane of polarization of the plane wave transmitted via the antenna,
Instructing the antenna to rotate the plane of polarization of the plane wave based on the determination. A first wireless communication device having a first antenna in which a first polarization plane of a plane wave to be transmitted is rotatably installed around an axis parallel to a transmission direction;
A second wireless communication device having a second antenna in which a second plane of polarization of the plane wave to be transmitted is rotatably installed around an axis parallel to the transmission direction, and facing the first wireless communication device in a communicable manner; ,
The first wireless communication device and the second wireless communication device each have a range in which an angle formed by the first polarization plane and the second polarization plane is set based on transmission quality of a plane wave received by one of the first and second wireless communication apparatuses. A wireless communication system for rotating the first and second polarization planes while maintaining the distances within the range.

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