JP2018032918A - Underwater communication system and underwater communication device - Google Patents

Abstract

[Problem] An underwater communication system and an underwater communication device that allow a receiving side to easily detect the position of a transmitting side communication device. [Solution] A first communication device (1) includes a laser transmitter (11) that couples multiple lasers from multiple first laser diodes (111a to 111e) to a first multimode fiber (113) and transmits the lasers to a second communication device (2), and a laser receiver (12) that receives the lasers from the second communication device. The second communication device includes a laser transmitter (21) that couples multiple lasers from multiple second laser diodes to a second multimode fiber and transmits the lasers to the first communication device, a laser receiver (22) that receives the lasers from the first multimode fiber, an analysis unit (24) that analyzes the lasers from the first multimode fiber received by the laser receiver (22) to determine the center position of the laser from the laser transmitter (11), and a device movement unit (25) that moves the second communication device to the center position of the laser from the laser transmitter (11) determined by the analysis unit (24). [Selected Figure] FIG.

Description

  The present invention relates to an underwater communication system and an underwater communication apparatus that perform laser communication in water.

  In recent years, underwater communication using a 450 nm band blue laser diode having good transmission characteristics in water is expected. Patent Document 1 uses a blue laser diode for underwater communication, and exchanges a transmission direction and a reception direction with each other between two communication devices that communicate with each other, even if the mutual position of the two communication devices fluctuates. Can send and receive data.

JP 2009-55408 A

  However, when a directional laser is transmitted from one communication device to the other communication device in order to increase the signal transmission distance, the other communication device can easily receive the directional laser. I couldn't. For this reason, the receiving side cannot easily detect the position of the communication device on the transmitting side.

  An object of the present invention is to provide an underwater communication system and an underwater communication apparatus that allow a reception side to easily detect the position of a communication device on a transmission side.

  An underwater communication system according to the present invention is an underwater communication system that performs communication between a first communication device and a second communication device in order to solve the above-described problem, and the first communication device includes a plurality of first communication devices. A first laser transmitter for coupling a plurality of lasers of one laser diode to a first multimode fiber and transmitting the laser to the second communication device; and a first laser receiver for receiving a laser from the second communication device. . The second communication device includes a second laser transmitter that couples a plurality of lasers of a plurality of second laser diodes to a second multimode fiber and transmits the second laser to the first communication device; A second laser receiver for receiving a laser; and a second analysis for determining a center position of the laser from the first laser transmitter by analyzing the laser from the first multimode fiber received by the second laser receiver. And a second moving unit that moves the second communication device to the center position of the laser from the first laser transmitter determined by the second analyzing unit.

  Further, in the underwater communication system of the present invention, the second laser transmitter transmits the movement completion information when the movement of the second communication device from the first laser transmitter to the center position of the laser is completed. Transmitting to the first communication device, and the first laser transmitter collimates the laser from the first multimode fiber after the first laser receiver receives the movement completion information, and the second communication device. It is characterized by transmitting to.

  The present invention is also an underwater communication device that communicates with another underwater communication device, wherein the other underwater communication device couples a plurality of lasers of a plurality of first laser diodes to a first multimode fiber. A laser receiver for receiving a laser from the first multi-mode fiber and a plurality of lasers of a plurality of second laser diodes coupled to the second multi-mode fiber to transmit the other multi-mode communication device. A laser transmitter for transmitting to the laser, an analysis unit for analyzing the laser from the first multimode fiber received by the laser receiver and determining a center position of the laser from the other underwater communication device, And a moving unit for moving the own underwater communication device to the center position of the laser from the other underwater communication device.

  According to the present invention, when the first laser transmitter couples the plurality of lasers of the plurality of first laser diodes arranged at predetermined intervals to the first multimode fiber and transmits it to the second communication device, The laser receiver receives a laser from the first multimode fiber. The second analysis unit analyzes the laser from the first multimode fiber to determine the center position of the laser from the first laser transmitter, and the second moving unit transmits the first laser transmission obtained by the second analysis unit. The second communication device is moved to the center position of the laser from the vessel.

  Therefore, the reception side can easily detect the position of the communication device on the transmission side, and stable communication can be performed after the position detection.

1 is a configuration block diagram of an underwater communication system according to a first embodiment. It is the figure which showed the mode output from the multimode fiber of the underwater communication system of Example 1, Comprising: This mode represents the light intensity distribution with respect to a horizontal direction position. 3 is a flowchart for explaining the operation of the underwater communication system according to the first embodiment. It is a figure which shows the state which the 2nd communication apparatus received the minimum value MN1 of the light intensity of the mode output from the multimode fiber of a 1st communication apparatus. It is a figure which shows the state which moved the 2nd communication apparatus to the center position of the laser which shows the maximum value MX of the light intensity of the mode output from the multimode fiber of a 1st communication apparatus. It is a figure which shows the state which collimated the laser from a multimode fiber, and transmitted to the 2nd communication apparatus after the 1st communication apparatus received the completion of movement of a 2nd communication apparatus. It is a block diagram of the main part of the underwater communication system according to the second embodiment. It is a figure which shows the relationship between the modulation speed of the underwater communication system of Example 2, and apparatus movement amount. FIG. 6 is a configuration block diagram of a main part of an underwater communication system according to a third embodiment. It is a figure which shows the relationship between the wavelength of the underwater communication system of Example 3, and apparatus movement amount.

  Hereinafter, embodiments of an underwater communication system and an underwater communication apparatus of the present invention will be described in detail with reference to the drawings.

Example 1
FIG. 1A is a configuration block diagram of the underwater communication system according to the first embodiment. FIG. 1B is a detailed configuration diagram of the laser transmitter.

  The underwater communication system according to the first embodiment performs laser communication between the first communication device 1 and the second communication device 2. The first communication device 1 includes a laser transmitter 11, a laser receiver 12, a control unit 13, an analysis unit 14, and a device moving unit 15.

  The laser transmitter 11 corresponds to the first laser transmitter of the present invention. As shown in FIG. 1B, the laser transmitter 11 combines a plurality of lasers of a plurality of laser diodes 111a to 111e arranged at predetermined intervals. And coupled to the multimode fiber 113 (the first multimode fiber of the present invention) and transmitted to the second communication device 2.

  The plurality of laser diodes 111a to 111e are 450 nm band blue laser diodes or green laser diodes.

  The multimode fiber 113 includes a core 114 having a large diameter necessary and sufficient for generating a multimode and a clad 115 surrounding the core 114, and has a fiber output light corresponding to the arrangement pattern of the plurality of laser diodes 111a to 111e. An intensity distribution occurs.

  FIG. 2 is a diagram illustrating a mode representing a light intensity distribution with respect to a lateral position output from the multimode fiber 113 of the underwater communication system according to the first embodiment. In the example shown in FIG. 2, the light intensity of the laser diodes 111a and 111e at both ends is set low, and the light intensity of the center laser diode 111c is set high. MN2, the center of the mode is the maximum value MX, and the mode has symmetrical light intensity.

  The laser receiver 12 corresponds to the first laser receiver of the present invention and receives a laser from the second communication device 2. The control unit 13 controls the laser transmitter 11 and the laser receiver 12.

  The analysis unit 14 corresponds to the first analysis unit of the present invention, and analyzes the mode from the second multimode fiber 113 received by the laser receiver 12 and analyzes the mode of the laser from the laser transmitter 21 based on the analyzed mode. Find the center position. The device moving unit 15 corresponds to the first moving unit of the present invention, and moves the first communication device 1 to the center position of the laser from the laser transmitter 21 obtained by the analyzing unit 14.

  The second communication device 2 includes a laser transmitter 21, a laser receiver 22, a control unit 23, an analysis unit 24, and a device moving unit 25.

  The laser transmitter 21 corresponds to the second laser transmitter of the present invention, and combines a plurality of lasers of a plurality of first laser diodes 111a to 111e arranged at predetermined intervals as shown in FIG. The lens 112 is coupled to the multimode fiber 113 (the second multimode fiber of the present invention) and transmitted to the first communication device 1.

  The laser receiver 22 corresponds to the second laser receiver of the present invention, and receives a mode from the multimode fiber 113 of the first communication device 1. The control unit 23 controls the laser transmitter 21 and the laser receiver 22.

  The analysis unit 24 corresponds to the second analysis unit of the present invention and analyzes the mode from the first multimode fiber 113 received by the laser receiver 22 and analyzes the mode of the laser from the laser transmitter 11 based on the analyzed mode. Find the center position. The device moving unit 25 corresponds to the second moving unit of the present invention, and moves the second communication device 2 to the center position of the laser from the laser transmitter 11 obtained by the analyzing unit 24.

  The laser transmitter 21 transmits movement completion information to the first communication device 1 when the movement of the second communication device 2 from the laser transmitter 11 to the center position of the laser is completed. The laser transmitter 11 collimates the laser from the multimode fiber 113 and transmits it to the second communication device 2 after the laser receiver 12 receives the movement completion information.

  The laser transmitter 11 transmits movement completion information to the second communication device 2 when the movement of the first communication device 1 from the laser transmitter 21 to the center position of the laser is completed. The laser transmitter 21 collimates the laser from the multimode fiber 113 and transmits it to the first communication device 1 after the laser receiver 22 receives the movement completion information.

  FIG. 3 is a flowchart for explaining the operation of the underwater communication system according to the first embodiment. Next, the operation of the underwater communication system will be described with reference to FIGS. Here, as an example, the operation when the first communication device 1 is the transmission side and the second communication device 2 is the reception side will be described. The same applies to the case where the second communication device 2 is the transmission side and the first communication device 1 is the reception side.

  First, from the multimode fiber 113, the first communication apparatus 1 has light intensity at both ends in the lateral direction as shown in FIG. 2 as the minimum values MN1 and MN2, and the light intensity at the center in the lateral direction as the maximum value MX. Is transmitted to the second communication device 2 (step S11). As shown in FIG. 4, this mode is a lateral mode having a spread with respect to the lateral position.

  Then, as shown in FIG. 4, the laser receiver 22 of the second communication device 2 receives and detects the mode minimum value MN1 from the multimode fiber 113 of the first communication device 1 (step S12). The analysis unit 24 analyzes the detected mode (step S13).

  This mode pattern is determined in advance between the first communication device 1 and the second communication device 2, and for example, the end of the lateral position of the mode is the minimum value MN1, and the center of the lateral position of the mode is the center. Is predetermined as the maximum value MX. In this case, the horizontal position of the maximum value MX is the center position of the laser from the multimode fiber 113 of the first communication device 1.

  For this reason, the analysis unit 24 calculates the movement amount of its own communication device where the mode value becomes the maximum value MX based on the minimum value MN1 and the gradient of the light intensity shown in FIG. The center position of the laser from the multimode fiber 113 of one communication device 1 is obtained (step S14). In this case, the analysis unit 24 decreases the movement amount of the communication device 2 as the inclination of the light intensity shown in FIG. 2, that is, tan θ is larger, and increases the movement amount of the communication device 2 as the tan θ is smaller. To do. Further, the position of the maximum value MX is predicted from the minimum value MN1.

  The device moving unit 25 moves the own communication device 2 based on the movement amount of the own communication device 2 calculated by the analysis unit 24, thereby moving the second communication device 2 to the center position of the laser of the first communication device 1. (Step S15). FIG. 5 shows a state in which the second communication device 2 is moved to the center position of the laser output from the multimode fiber 113 of the first communication device 1.

  Next, when the movement is completed, the second communication device 2 transmits a ready state to the first communication device 1 (step S16). After the first communication device 1 receives the completion of movement of the second communication device 2, the communication state between the second communication device 2 and the first communication device 1 is established (step S17).

  Next, as shown in FIG. 6, the first communication device 1 collimates the laser from the multimode fiber 113 with the collimating lens 16 and transmits it to the second communication device 2 (step S <b> 18). Thereby, the stable communication can be performed between the 1st communication apparatus 1 and the 2nd communication apparatus 2 (step S19).

  Thus, according to the underwater communication system of the first embodiment, the laser transmitter 11 couples the plurality of lasers of the plurality of laser diodes 111a to 111e arranged at predetermined intervals to the multimode fiber 113 to perform the second communication. Transmit to device 2. Then, the laser receiver 22 receives the mode from the multimode fiber 113, and the analysis unit 24 analyzes the mode from the multimode fiber 113 and obtains the center position of the laser from the laser transmitter 11. The device moving unit 25 moves the second communication device 2 to the center position of the laser from the laser transmitter 11 obtained by the analyzing unit 24.

  Accordingly, it is possible to provide an underwater communication system and an underwater communication device that allow the receiving side to easily detect the position of the communication device on the transmitting side and perform stable communication with a high SN ratio after position detection. it can.

(Example 2)
FIG. 7 is a configuration block diagram of a main part of the underwater communication system according to the second embodiment. The underwater communication system according to the second embodiment is characterized in that a modulation rate control unit 13a is used instead of the control unit 13 with respect to the configuration of the underwater communication system according to the first embodiment.

  As described in the first embodiment, different laser intensities are set in advance for the plurality of laser diodes 111a to 111e.

  The modulation speed control unit 13a controls the modulation speed individually for the plurality of laser diodes 111a to 111e. For example, the modulation speed control unit 13a has the highest modulation speed for the laser diode 111c, and the laser diodes 111a and 111e On the other hand, modulation speed information is added to the plurality of laser diodes 111a to 111e by slowing down the modulation speed. The modulation speed can be changed by shortening or lengthening the period for turning on / off the laser diode.

  For this reason, the laser transmitter 11 transmits a laser to which the mode and the modulation speed information are added to the second communication device 2. The laser receiver 22 receives and detects the mode and modulation speed information from the multimode fiber 113 of the first communication device 1. The analysis unit 24 analyzes the detected mode and modulation speed information. The mode analysis is as described in the first embodiment.

  The pattern of the modulation rate information is determined in advance between the first communication device 1 and the second communication device 2. In this case, the position where the modulation speed is the fastest is the center position of the laser from the multimode fiber 113 of the first communication device 1.

  For this reason, the analysis unit 24 obtains the center position of the laser on the transmission side by calculating the amount of movement of its own communication device where the modulation speed is the fastest based on the modulation speed information. FIG. 8 shows the relationship between the modulation speed and the device movement amount.

  The device moving unit 25 moves the own communication device 2 based on the movement amount of the own communication device 2 calculated by the analysis unit 24, thereby moving the second communication device 2 to the center position of the laser of the first communication device 1. Move to.

  According to the underwater communication system of the second embodiment, since the mode and the modulation speed information are used, the center position of the laser can be analyzed more clearly than the underwater communication system of the first embodiment.

(Example 3)
FIG. 9 is a configuration block diagram of a main part of the underwater communication system according to the third embodiment. In FIG. 9, for example, the first communication device 1 is a transmission side, and the second communication device 2 is a reception side. The second communication device 2 may be the transmission side and the first communication device 1 may be the reception side.

  In the plurality of laser diodes 111a to 111e on the transmission side in FIG. 9, different wavelengths are set in advance. In the example shown in FIG. 9, the laser diode 111c oscillates at the shortest wavelength λmin, the laser diodes 111a and 111e oscillate at the longest wavelength λmax, and the laser diodes 111b and 111d oscillate at the intermediate wavelength λmid.

  For this reason, the laser transmitter 11 transmits lasers having different wavelengths to the second communication device 2. The spectrum analyzer 22a composed of a laser receiver receives lasers having different wavelengths from the multimode fiber 113 of the first communication apparatus 1 and detects different wavelengths. The analysis unit 24 analyzes the detected different wavelengths.

  Different wavelength patterns are determined in advance between the first communication device 1 and the second communication device 2. In this case, the position where the wavelength is the shortest is the center position of the laser from the multimode fiber 113 of the first communication device 1.

  For this reason, the analysis unit 24 obtains the center position of the laser on the transmitting side by calculating the amount of movement of its own communication device that has the shortest wavelength based on the received different wavelengths. FIG. 10 shows the relationship between the wavelength and the amount of device movement.

  The device moving unit 25 moves the own communication device 2 based on the movement amount of the own communication device 2 calculated by the analysis unit 24, thereby moving the second communication device 2 to the center position of the laser of the first communication device 1. Move to.

  According to the underwater communication system of the third embodiment, since different wavelengths are used, the same effect as the underwater communication system of the first embodiment can be obtained.

  In the underwater communication system and the underwater communication device according to the first to third embodiments, each of the first communication device 1 and the second communication device 2 includes the analysis unit and the device moving unit. The analysis unit 24 and the device moving unit 25 may be provided only in the second communication device 2. Alternatively, the analysis unit 14 and the device moving unit 15 may be provided only in the first communication device 1.

  Further, in the underwater communication system and the underwater communication apparatus of Examples 1 and 2, the light intensity of the laser diode 111c arranged at the center was set larger than the light intensity of the laser diodes 111a and 111e arranged at both ends. For example, the light intensity of the laser diode 111c arranged at the center may be set smaller than the light intensity of the laser diodes 111a and 111e arranged at both ends.

  The underwater communication system according to the present invention can be applied to a laser communication apparatus.

DESCRIPTION OF SYMBOLS 1 1st communication apparatus 2 2nd communication apparatus 11,21 Laser transmitter 12,22 Laser receiver 13,23 Control part 13a Modulation speed control part 14,24 Analysis part 15,25 Apparatus moving part 16 Collimating lens 22a Spectrum analyzer 111a ~ 111e Laser diode 112 Coupled lens 113 Multimode fiber 114 Core 115 Clad MN1, MN2 Minimum value MX Maximum value

Claims (7)

An underwater communication system that performs communication between a first communication device and a second communication device,
The first communication device is
A first laser transmitter for coupling a plurality of lasers of a plurality of first laser diodes to a first multimode fiber and transmitting to the second communication device;
A first laser receiver for receiving a laser from the second communication device,
The second communication device is
A second laser transmitter for coupling a plurality of lasers of a plurality of second laser diodes to a second multimode fiber and transmitting to the first communication device;
A second laser receiver for receiving a laser from the first multimode fiber;
A second analyzer for analyzing the laser from the first multimode fiber received by the second laser receiver to determine the center position of the laser from the first laser transmitter;
A second moving unit that moves the second communication device to the center position of the laser from the first laser transmitter determined by the second analyzing unit;
An underwater communication system comprising: The second laser transmitter transmits movement completion information to the first communication device when the movement of the second communication device to the center position of the laser from the first laser transmitter is completed,
The first laser transmitter collimates a laser beam from the first multimode fiber and transmits the laser beam to the second communication device after the first laser receiver receives the movement completion information. The underwater communication system according to claim 1. The first communication device further includes:
A first analysis unit for analyzing a laser from the second multimode fiber received by the first laser receiver and obtaining a center position of the laser from the second laser transmitter;
A first moving unit that moves the first communication device to a center position of a laser from the second laser transmitter determined by the first analyzing unit;
The underwater communication system according to claim 1, further comprising: The first multi-mode fiber outputs a mode indicating a light intensity distribution in which light intensity is set according to an arrangement of the plurality of first laser diodes;
The second laser receiver receives the mode from the first multimode fiber;
2. The second analysis unit analyzes the mode received by the second laser receiver and obtains the center position of the laser from the first laser transmitter based on the analyzed mode. The underwater communication system according to claim 3.   The underwater communication system according to claim 4, further comprising a modulation speed control unit that individually controls a modulation speed for the plurality of first laser diodes. The plurality of first laser diodes are individually set with different wavelengths in advance,
The second laser receiver receives the different wavelengths from the first multimode fiber;
The said 2nd analysis part calculates | requires the center position of the laser from a said 1st laser transmitter based on the analyzed wavelength which analyzed the said different wavelength received with the said 2nd laser receiver. The underwater communication system according to any one of claims 3 to 3. An underwater communication device that communicates with other underwater communication devices,
A laser receiver that receives a laser from the first multimode fiber when the other underwater communication device transmits a plurality of lasers of a plurality of first laser diodes coupled to the first multimode fiber;
A laser transmitter that couples a plurality of lasers of a plurality of second laser diodes to a second multimode fiber and transmits to the other underwater communication device;
Analyzing the laser from the first multimode fiber received by the laser receiver to determine the center position of the laser from the other underwater communication device;
A moving unit that moves the own underwater communication device to the center position of the laser from the other underwater communication device obtained by the analysis unit;
An underwater communication device comprising:

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