KR102328882B1 - Differential mode underwater optical wireless communication method and system using optical separation lens and bandpass filter - Google Patents

Abstract

Disclosed are a differential mode underwater optical wireless communication method using an optical separation lens and a bandpass filter, which increase a peak-to-peak voltage swing of an optical detection signal, and a system thereof. According to one embodiment of the present invention, the method comprises the following steps: transmitting an optical signal through a plurality of independently controllable light sources in the water by using an optical signal transmitter; and using an optical separation lens or a bandpass filter to cancel noise signals or DC offset errors caused by turbidity or ambient light interference from a plurality of optical signals simultaneously incident from a plurality of light sources to an optical signal receiver and amplifying peak-to-peak voltage swings of the plurality of optical signals.

Description

DIFFERENTIAL MODE UNDERWATER OPTICAL WIRELESS COMMUNICATION METHOD AND SYSTEM USING OPTICAL SEPARATION LENS AND BANDPASS FILTER

The following embodiments relate to a differential mode underwater optical wireless communication method and system using an optical separation lens and a bandpass filter.

Recently, with the increase of interest in the sea in each country, the development and use of underwater drones are increasing, and their missions are gradually diversifying. In order to operate this at a lower cost and more efficiently, a system that wirelessly retrieves the Side Scan Sonar and Multi-Beam Sounder underwater terrain mapping data without lifting the AUV on duty, an underwater glider on a long-range mission or an underwater observation node buried in the seabed A system that remotely recovers large amounts of data acquired by rendezvous with a communication node or USV (unmanned aerial vehicle) installed in the water, and a tether cable that is easy to operate on subsea platforms such as subsea drilling facilities that require periodic investigation and work Real-time wireless remote control operation system for ROV, low visibility and covert underwater communication system for military submarines and military underwater drones, a system that builds a wide area underwater communication network and collects various underwater information and transmits it to the ground through an underwater base station. Ideas are being proposed. As a key means for realizing this idea, communication technology that quickly transmits a large amount of information underwater is becoming an increasingly important issue.

Currently, acoustic wave communication is capable of long-distance propagation in the water, but it is difficult to transmit a large amount of data in water at high speed due to a low bandwidth problem. As a way to solve this problem, the Woods Hole Oceanographic Research Institute (WHOI) in the US has been conducting research on high-speed underwater communication using blue light lasers and LEDs since 2006, and has achieved remarkable results in the ocean. In addition, Sonardyne International Ltd, a well-known company in the field of acoustic wave communication equipment in the UK, has commercialized an underwater optical wireless communication modem through a technology agreement with the Woods Hole Marine Research Institute, and the related market is growing significantly.

Recently, interest in underwater wireless optical communication is developing technology to increase communication distance and increase data transmission speed. Communication distance in the ocean is directly related to turbidity. As the turbidity is lower, the communication distance increases and communication data can also be increased. However, in an area with low turbidity, unless the ocean has a certain depth, sunlight or ambient light affects the light receiving sensor and acts as a noise to interfere with communication. This method of reducing the influence of ambient light is not only important for increasing the communication distance and data of underwater wireless optical communication, but also very important for extending the area or time period of using it.

Light passing through an underwater channel with turbidity collides with particles distributed in the water, scatters in an uncertain path, and reaches the receiver sensor to generate noise. In addition, ambient light interference by sunlight causes unwanted DC offset to weaken the maximum voltage swing of the photodetection signal.

S. Bloom, E. Korevaar, J. Schuster, and H. Willebrand, ``Understanding the performance of free-space optics,'' J. Opt. Network., vol. 2, no. 6, pp. 178-200, 2003.

The embodiments describe a differential mode underwater optical wireless communication method and system using an optical separation lens and a bandpass filter, and more specifically, the maximum voltage swing ( It provides technology that can improve peak-to-peak voltage).

Embodiments establish a structure for communicating with a plurality of light sources and a plurality of light detection sensors by using a light separation lens that separates light rays received from a plurality of light sources at once by the principle of refraction to form a dispersed image at a certain position, and this structure A differential mode underwater optical wireless communication method using an optical separation lens and a bandpass filter that can amplify the maximum voltage swing of the light source signal while canceling and canceling the noise signal caused by turbidity and ambient light interference by applying a differential signal structure to the to provide a system.

In addition, the embodiments apply a bandpass filter (wavelength band filter) that passes light of a specific wavelength as the optical signals having different wavelengths are transmitted in different phases so that only optical signals of a specific wavelength can be detected. Differential mode underwater using an optical separation lens and bandpass filter that can amplify the maximum voltage swing of the light source signal while canceling and canceling the noise signal caused by turbidity and ambient light interference by applying a differential signal structure to this structure To provide an optical wireless communication method and system.

Underwater optical wireless communication method according to an embodiment, transmitting an optical signal through a plurality of light sources each independently controllable underwater using an optical signal transmitter; and a noise signal or DC offset generated by turbidity or ambient light interference using an optical separation lens or a band pass filter for the plurality of optical signals simultaneously incident from the plurality of light sources to the optical signal receiver. ) canceling the error and amplifying the maximum voltage swing of the plurality of optical signals.

The transmitting of the optical signal through the plurality of light sources may include transmitting a square wave first light source having a specific frequency and a second light source having an opposite phase to the first light source.

The step of amplifying the maximum voltage swing of the plurality of optical signals may include: refracting the plurality of optical signals simultaneously incident from the plurality of light sources using the optical separation lens; and imaging the plurality of refracted optical signals through a plurality of independently arranged optical sensors.

The amplifying the maximum voltage swing of the plurality of optical signals may include: classifying the plurality of optical signals simultaneously incident from the plurality of light sources by wavelength using the bandpass filter; and detecting each wavelength of the plurality of optical signals classified by wavelength through the plurality of optical sensors arranged independently.

In the step of amplifying the maximum voltage swing of the plurality of optical signals, the plurality of light sources and the plurality of optical sensors form a pair to transmit and receive optical signals, and collect signals output from each pair A noise signal of the same phase may be canceled, and an original signal of a different phase may be amplified through a differential amplifier.

Underwater optical wireless communication system according to another embodiment, an optical signal transmitter for transmitting an optical signal through a plurality of light sources each independently controllable in the water; and a noise signal or DC offset error generated by turbidity or ambient light interference using an optical separation lens or a band pass filter for the plurality of optical signals simultaneously incident from the plurality of light sources and an optical signal receiver for amplifying the maximum voltage swing of the plurality of optical signals.

The optical signal transmitter may transmit a square wave first light source having a specific frequency and a second light source having an opposite phase to the first light source.

The optical signal receiver may include: an optical separation lens configured to refract the plurality of optical signals simultaneously incident from the plurality of light sources; and a plurality of independently arranged optical sensors for imaging the plurality of refracted optical signals.

The optical signal receiver may include: a bandpass filter for classifying the plurality of optical signals simultaneously incident from the plurality of light sources by wavelength; and the plurality of optical sensors arranged independently for detecting each wavelength from the plurality of optical signals classified by wavelength.

In the optical signal receiver, the plurality of light sources and the plurality of optical sensors each form a pair to transmit and receive optical signals, collect signals output from each pair to cancel a noise signal of the same phase, It may include a differential amplifier for amplifying the original signals of different phases.

According to embodiments, a differential mode underwater using an optical separation lens and a bandpass filter capable of effectively removing scattered light noise and ambient light noise caused by turbidity and improving the peak-to-peak voltage of the light detection signal It is possible to provide an optical wireless communication method and system.

In addition, according to embodiments, it is possible to remove in-phase noise such as scattered light incident noise, increase the optical transmission/reception distance by improving the signal-to-noise ratio by improving the voltage swing by the phase difference amplification principle, and increase the transmission speed with multiple transmission signals It is possible to provide a differential mode underwater optical wireless communication method and system using an optical separation lens and a bandpass filter.

1 is a diagram for explaining an example of a signal subjected to ambient light interference according to an embodiment.
2 is a flowchart illustrating an underwater optical wireless communication method according to an embodiment.
3 is a block diagram illustrating an underwater optical wireless communication system according to an embodiment.
4 is a view for explaining a differential mode underwater optical wireless communication system using an optical separation lens according to an embodiment.
5 is a diagram for explaining a driving principle of a differential mode underwater optical wireless communication system using an optical separation lens according to an embodiment.
6 is a diagram for explaining a differential mode underwater optical wireless communication system using a bandpass filter according to an embodiment.
7 is a diagram for explaining a driving principle of a differential mode underwater optical wireless communication system using a bandpass filter according to an embodiment.
8 is a diagram for explaining a performance experiment of a differential mode underwater optical wireless communication system using a bandpass filter according to an embodiment.
9 is a view showing a performance test result of a differential mode underwater optical wireless communication system using a bandpass filter according to an embodiment.

Hereinafter, embodiments will be described with reference to the accompanying drawings. However, the described embodiments may be modified in various other forms, and the scope of the present invention is not limited by the embodiments described below. In addition, various embodiments are provided in order to more completely explain the present invention to those of ordinary skill in the art. The shapes and sizes of elements in the drawings may be exaggerated for clearer description.

In order to overcome this problem, the following embodiments provide the following two methods that can improve the peak-to-peak voltage of the light detection signal while effectively removing the scattered light noise and ambient light noise caused by turbidity. suggest One is a differential mode underwater optical wireless communication method using an optical separation lens, and the other is a differential mode underwater optical wireless communication method using a bandpass filter.

When predicting the change of light passing through seawater theoretically, there are absorption coefficients of water molecules in seawater according to wavelength and scattering coefficients due to floating matter and plankton distributed in seawater. is an important variable that determines the performance of underwater visible light communication.

Table 1 below shows the absorption coefficient, scattering coefficient and attenuation coefficient for 514nm wavelength in various seawater environments.

[Table 1]

The absorption coefficient is a unique property of water molecules, and the value does not change significantly depending on the water body and shows a characteristic that depends on the wavelength of light. On the other hand, the scattering coefficient is related to turbidity, and the coefficient value varies greatly depending on the degree of turbidity of the water body.

In addition, the light passing through the turbid water channel collides with the particles distributed in the water, scatters in an uncertain path, and arrives at the optical receiver sensor, which is the main cause of noise.

1 is a diagram for explaining an example of a signal subjected to ambient light interference according to an embodiment.

In shallow waters, ambient light interference by sunlight is easy to occur, and from the viewpoint of the light sensor output signal, ambient light interference causes an unwanted DC offset to weaken the maximum voltage swing of the light detection signal, so it is difficult to restore the light detection signal. make it difficult Referring to FIG. 1 , an example of a signal subjected to ambient light interference is shown. 110 denotes a signal subjected to ambient light interference, and 120 denotes a normal signal.

In the ocean, there are few suspended matter such as organic matter and sand particles, so the scattering coefficient is small, and as you go down to the deep sea, you do not receive any interference by sunlight. The optical communication system developed by the Woods Hole Oceanographic Research Institute in the United States is designed for use in the deep-sea environment of the Atlantic and Pacific oceans. It uses a PMT sensor that has a very high photoelectric gain compared to a semiconductor optical sensor. Communication speed has been achieved. And Sonadyne, a British company that signed a technical agreement with the Woods Hall Ocean Research Institute, has also commercialized a deep-sea optical wireless communication modem capable of communication speeds of up to 12.5Mbps and up to 150M in deep-sea environments. Table 2 below shows the specifications of the underwater optical wireless communication modem technology developed by the Woods Hole Oceanographic Research Institute as of 2015.

[Table 2]

On the other hand, the water area around Korea is a shallow sea environment with low water depth, and the bottom of the sea is mostly mud. In such a shallow sea environment, a very sensitive light detection sensor such as PMT amplifies a noise optical signal by a noise element as well, so it is difficult to actually apply the sensor technology alone in a shallow sea environment. Accordingly, in order to improve the underwater visible light communication performance, there is a need for a method capable of effectively removing noise caused by scattering and ambient light while improving the maximum voltage swing of the light detection signal.

2 is a flowchart illustrating an underwater optical wireless communication method according to an embodiment.

Referring to FIG. 2 , the underwater optical wireless communication method according to an embodiment includes transmitting an optical signal through a plurality of independently controllable light sources in the water using an optical signal transmitter (S110), and a plurality of light sources A plurality of optical signals simultaneously incident to the optical signal receiver from The step of amplifying the maximum voltage swing of the plurality of optical signals ( S120 ) may be included.

Here, the amplifying the maximum voltage swing of the plurality of optical signals includes: refracting the plurality of optical signals simultaneously incident from the plurality of light sources using an optical separation lens, and independently disposing the plurality of refracted optical signals It may include forming an image through a plurality of optical sensors.

In addition, the amplifying the maximum voltage swing of the plurality of optical signals includes: classifying a plurality of optical signals simultaneously incident from a plurality of light sources by wavelength using a bandpass filter, and dividing the plurality of optical signals classified by wavelength The method may include detecting each wavelength through a plurality of independently arranged optical sensors.

Each step of the underwater optical wireless communication method according to an embodiment will be described below.

The underwater optical wireless communication method according to an embodiment can be described as an example through the underwater optical wireless communication system according to an embodiment.

3 is a block diagram illustrating an underwater optical wireless communication system according to an embodiment.

Referring to FIG. 3 , the underwater optical wireless communication system 300 according to an embodiment may include an optical signal transmitter 310 and an optical signal receiver 320 , and the optical signal receiver 320 includes a differential amplifier. may include Here, according to an embodiment, the underwater optical wireless communication system 300 may include the optical signal receiver 320 including an optical separation lens and a plurality of optical sensors. In addition, the underwater optical wireless communication system 300 may include a bandpass filter and a plurality of optical sensors.

In step S110 , the optical signal transmitter 310 may transmit an optical signal through a plurality of independently controllable light sources in water. For example, the optical signal transmitter 310 may transmit a square wave first light source having a specific frequency and a second light source having an opposite phase to the first light source.

In step S120 , the optical signal receiver 320 receives a plurality of optical signals simultaneously incident from a plurality of light sources using an optical separation lens or a band pass filter to generate noise caused by turbidity or ambient light interference. It is possible to cancel a signal or DC offset error, and to amplify the maximum voltage swing of a plurality of optical signals.

For example, the optical signal receiver 320 may include an optical separation lens and a plurality of optical sensors. Accordingly, a plurality of optical signals simultaneously incident from a plurality of light sources may be refracted using an optical separation lens, and the plurality of refracted optical signals may be imaged through a plurality of independently arranged optical sensors.

As another example, the optical signal receiver 320 may include a bandpass filter and a plurality of optical sensors. Accordingly, a plurality of optical signals simultaneously incident from a plurality of light sources are classified by wavelength using a bandpass filter, and each wavelength can be detected through a plurality of independently arranged optical sensors for a plurality of optical signals classified by wavelength. have.

Also, the optical signal receiver 320 may include a differential amplifier. Accordingly, the plurality of light sources and the plurality of optical sensors each form a pair to transmit and receive optical signals, collect signals output from each pair to cancel noise signals of the same phase, and original signals of different phases It can be amplified through a differential amplifier.

Below, a differential mode underwater optical wireless communication method and system using an optical separation lens or a bandpass filter will be divided and described in more detail.

Differential mode underwater optical wireless communication method using optical separation lens

A structure for communicating with a plurality of light sources and a plurality of light detection sensors is established using a light separation lens that separates the light rays received from a plurality of light sources at once by the principle of refraction to form a dispersed image at a certain position, and a differential signal is applied to this structure By applying the structure, it is possible to provide an underwater optical wireless communication system capable of amplifying the maximum voltage swing of a light source signal while canceling and canceling a noise signal caused by turbidity and ambient light interference.

4 is a view for explaining a differential mode underwater optical wireless communication system using an optical separation lens according to an embodiment.

4, it shows a differential mode underwater optical wireless communication system using an optical separation lens according to an embodiment, wherein a plurality of light sources 411 and 412 and a plurality of light sensors 431 and 432 are each two. Assume and explain That is, an underwater optical wireless communication system of a dual-channel transmission mode will be described as an example. If two or more visible ray wavelengths with good transmittance in seawater are selected, and a light receiving system that can selectively detect only the selected visible ray wavelength is developed and applied to an underwater wireless communication system, the By solving the problems, it is possible to provide a better communication system as a result.

The first light source 411 and the second light source 412 may each transmit an optical signal by inverting the phase. The light separation lens 420 separates the light bundles incident at once from the plurality of light sources 411 and 412 by the principle of refraction so that they are dispersed and imaged at a predetermined position, and at this time, the first optical sensor ( 431 and the second optical sensor 432 may receive a signal from each light source. That is, the first light source 411 <-> the second light sensor 432, the second light source 412 <-> the first light sensor 431 forms a pair to transmit and receive signals, and in this case, the pair ) can be said.

For example, a BLUE LED and a BLUE Laser can be used as the light sources 411 and 412 of the optical signal transmitter of the underwater optical wireless communication system, and a case in which the BLUE LED is used as the light sources 411 and 412 will be described. . Basically, LED, LED Driver, and Collimate Lens are composed of one set module, and a total of 2 modules can be configured. And since one of the two modules must operate in the opposite phase of the input PWM signal, it can be configured by placing an inverter at the input terminal of one module.

A lens disposed at the front end of a general optical signal receiver is designed for the purpose of condensing the received light to increase the intensity of the light irradiated to the optical sensors 431 and 432, but in this case, from the light sources 411 and 412 at different positions A light separation lens 420 designed to separate a bundle of rays incident at once by the principle of refraction and disperse and form an image at a predetermined position may be applied. The current signal output from the optical sensors 431 and 432 is converted into a voltage signal through the differential amplifier 440 of the previous stage. Accordingly, it is possible to demodulate a signal while effectively removing noise.

5 is a diagram for explaining a driving principle of a differential mode underwater optical wireless communication system using an optical separation lens according to an embodiment.

Referring to FIG. 5 , light sources 511 and 512 having different phases may be transmitted through an underwater channel having turbidity. The optical signal passing through the turbid water channel collides with the particles distributed in the water, scatters in an uncertain path, is refracted by the optical separation lens 520, and then reaches the optical sensors 531 and 532 of the optical signal receiver. noise, and ambient light interference by sunlight causes an unwanted DC offset to weaken the maximum voltage swing of the photodetection signal.

At this time, since noise due to scattering, ambient light noise, etc. give the same noise signal in the same phase to each optical sensor 531 and 532, the signal output from each pair is canceled in the same phase and the other phase is amplified. By passing through 540, noise is removed and a demodulated signal having an amplified maximum voltage swing can be obtained, and consequently, a signal to noise ratio (SNR) can be improved.

Such a structure can also be implemented as a wavelength band filter that selectively transmits a specific visible light wavelength.

Differential mode underwater optical wireless communication method using bandpass filter

6 is a diagram for explaining a differential mode underwater optical wireless communication system using a bandpass filter according to an embodiment.

Referring to FIG. 6 , the optical signal transmitter is configured to transmit optical signals 611 and 612 having different wavelengths in different phases, and the optical signal receiver includes a bandpass filter (wavelength) that passes light of a specific wavelength. A plurality of optical sensors 631 and 632 can be configured by applying band filters) 621 and 622 to detect only an optical signal of a specific wavelength.

A plurality of optical sensors 631 and 632 equipped with wavelength band filters 621 and 622 detect incident light of a specific wavelength and output a signal, and at this time, noise of the same phase component due to turbidity and DC offset due to ambient light Errors and the like can be detected in the same way. Here, when the output signals of the plurality of optical sensors 631 and 632 are differentially amplified, noise of the in-phase component can be canceled and the original signal can be amplified.

7 is a diagram for explaining a driving principle of a differential mode underwater optical wireless communication system using a bandpass filter according to an embodiment.

Referring to FIG. 7 , a differential mode underwater optical wireless communication system using a bandpass filter according to an embodiment may include an optical signal transmitter and an optical signal receiver. The optical signal transmitter may select two or more wavelengths of a cyan wavelength band (450 to 580 nm), which have the best transmittance in water, as a light source source, and may independently transmit information. In addition, the optical signal receiver may be configured by mounting two or more optical detection sensors designed to detect only optical signals of specific wavelengths.

8 is a diagram for explaining a performance experiment of a differential mode underwater optical wireless communication system using a bandpass filter according to an embodiment.

Referring to FIG. 8 , a performance experiment platform can be configured to check whether the designed bandpass filter works well. For example, in a 2.4M acrylic tank, different data signal waveforms were applied to a 450NM light source and a 520NM light source, respectively, and the signal waveforms detected at the receiving end to which a bandpass filter was applied were observed with an oscilloscope and a logic analyzer.

As a result of the experiment, even if blue-green light waves are simultaneously emitted as different signal waveforms, each band-pass filter transmits only the designed wavelength and is detected by the light detection sensor, confirming that the band-pass filter works well.

9 is a view showing a performance test result of a differential mode underwater optical wireless communication system using a bandpass filter according to an embodiment.

Referring to FIG. 9 , a performance test result for verifying the effect of a differential mode underwater optical wireless communication system using a bandpass filter according to an embodiment is shown. When looking at a signal detected by an optical signal receiver, turbidity or external factors It can be seen that a large amount of noise is generated by When demodulation is performed by applying the structure according to the embodiments, noise of the in-phase component is removed, effectively eliminating noise caused by turbidity and ambient light without applying separate signal processing, while completely demodulating the voltage swing to a level close to the maximum. It can be confirmed that

Embodiments may have the following advantages in underwater optical communication. DC offset error is automatically cleared, and an offset control device is unnecessary. In-phase noise such as scattered light incident noise is removed, and the signal-to-noise ratio can be increased by improving the voltage swing with the phase difference amplification principle. Also, it is possible to increase the transmission speed with multiple transmission signals.

The device described above may be implemented as a hardware component, a software component, and/or a combination of the hardware component and the software component. For example, devices and components described in the embodiments may include, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable array (FPA), It may be implemented using one or more general purpose or special purpose computers, such as a programmable logic unit (PLU), microprocessor, or any other device capable of executing and responding to instructions. The processing device may execute an operating system (OS) and one or more software applications running on the operating system. The processing device may also access, store, manipulate, process, and generate data in response to execution of the software. For convenience of understanding, although one processing device is sometimes described as being used, one of ordinary skill in the art will recognize that the processing device includes a plurality of processing elements and/or a plurality of types of processing elements. It can be seen that can include For example, the processing device may include a plurality of processors or one processor and one controller. Other processing configurations are also possible, such as parallel processors.

Software may comprise a computer program, code, instructions, or a combination of one or more of these, which configures a processing device to operate as desired or is independently or collectively processed You can command the device. The software and/or data may be any kind of machine, component, physical device, virtual equipment, computer storage medium or device, to be interpreted by or to provide instructions or data to the processing device. may be embodied in The software may be distributed over networked computer systems, and stored or executed in a distributed manner. Software and data may be stored in one or more computer-readable recording media.

The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc. alone or in combination. The program instructions recorded on the medium may be specially designed and configured for the embodiment, or may be known and available to those skilled in the art of computer software. Examples of the computer-readable recording medium include magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic such as floppy disks. - includes magneto-optical media, and hardware devices specially configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine language codes such as those generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like.

As described above, although the embodiments have been described with reference to the limited embodiments and drawings, various modifications and variations are possible from the above description by those skilled in the art. For example, the described techniques are performed in a different order than the described method, and/or the described components of the system, structure, apparatus, circuit, etc. are combined or combined in a different form than the described method, or other components Or substituted or substituted by equivalents may achieve an appropriate result.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

Claims (10)

transmitting an optical signal through a plurality of independently controllable light sources in the water using an optical signal transmitter; and
A noise signal or DC offset generated by turbidity or ambient light interference using an optical separation lens or a band pass filter for the plurality of optical signals simultaneously incident from the plurality of light sources to the optical signal receiver canceling the error and amplifying the maximum voltage swing of the plurality of optical signals;
including,
The optical signal transmitter includes a square wave first light source having a specific frequency and a second light source having an opposite phase to the first light source,
In the second light source, an inverter for the opposite phase to the first light source is disposed at the input end,
The optical signal receiver includes a plurality of optical sensors including a first optical sensor and a second optical sensor, and a differential amplifier,
Each pair is formed between the light source and the optical sensor to transmit and receive optical signals,
The step of amplifying the maximum voltage swing of the plurality of optical signals comprises:
Collecting signals output from each pair, canceling a noise signal of the same phase and amplifying an original signal of a different phase through the differential amplifier
characterized in that, the underwater optical wireless communication method. delete According to claim 1,
The step of amplifying the maximum voltage swing of the plurality of optical signals comprises:
refracting the plurality of optical signals simultaneously incident from the plurality of light sources using the optical separation lens; and
imaging the plurality of refracted optical signals through the plurality of independently arranged optical sensors
Including, underwater optical wireless communication method. According to claim 1,
The step of amplifying the maximum voltage swing of the plurality of optical signals comprises:
classifying the plurality of optical signals simultaneously incident from the plurality of light sources by wavelength using the bandpass filter; and
Detecting each wavelength through the plurality of optical sensors arranged independently of the plurality of optical signals classified by wavelength
Including, underwater optical wireless communication method. delete an optical signal transmitter for transmitting an optical signal through a plurality of independently controllable light sources in the water; and
A noise signal or DC offset error generated by turbidity or ambient light interference by using an optical separation lens or a band pass filter for the plurality of optical signals simultaneously incident from the plurality of light sources, and , an optical signal receiver for amplifying the maximum voltage swing of the plurality of optical signals
including,
The optical signal transmitter includes a square wave first light source having a specific frequency and a second light source having an opposite phase to the first light source,
In the second light source, an inverter for the opposite phase to the first light source is disposed at the input end,
The optical signal receiver includes a plurality of optical sensors including a first optical sensor and a second optical sensor, and a differential amplifier,
Each pair is formed between the light source and the optical sensor to transmit and receive optical signals,
The optical signal receiver,
Collecting signals output from each pair, canceling a noise signal of the same phase and amplifying an original signal of a different phase through the differential amplifier
characterized in that, an underwater optical wireless communication system. delete 7. The method of claim 6,
The optical signal receiver,
a light separation lens that refracts the plurality of optical signals simultaneously incident from the plurality of light sources; and
The plurality of independently arranged optical sensors for imaging the plurality of refracted optical signals
Including, an underwater optical wireless communication system. 7. The method of claim 6,
The optical signal receiver,
a bandpass filter for classifying the plurality of optical signals simultaneously incident from the plurality of light sources by wavelength; and
The plurality of independently arranged optical sensors for detecting each wavelength from the plurality of optical signals classified by wavelength
Including, an underwater optical wireless communication system. delete

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