CN112291019A - Underwater wireless optical communication method and system - Google Patents
Underwater wireless optical communication method and system Download PDFInfo
- Publication number
- CN112291019A CN112291019A CN202011618350.6A CN202011618350A CN112291019A CN 112291019 A CN112291019 A CN 112291019A CN 202011618350 A CN202011618350 A CN 202011618350A CN 112291019 A CN112291019 A CN 112291019A
- Authority
- CN
- China
- Prior art keywords
- optical
- signal
- original
- dpsk
- underwater wireless
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/80—Optical aspects relating to the use of optical transmission for specific applications, not provided for in groups H04B10/03 - H04B10/70, e.g. optical power feeding or optical transmission through water
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/50—Transmitters
- H04B10/516—Details of coding or modulation
- H04B10/548—Phase or frequency modulation
- H04B10/556—Digital modulation, e.g. differential phase shift keying [DPSK] or frequency shift keying [FSK]
- H04B10/5561—Digital phase modulation
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/60—Receivers
- H04B10/66—Non-coherent receivers, e.g. using direct detection
- H04B10/69—Electrical arrangements in the receiver
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Optical Communication System (AREA)
Abstract
The invention discloses an underwater wireless optical communication method and system, wherein the method comprises the following steps: controlling a sending end to pre-code an original electric signal and perform phase modulation on the light by using an optical phase modulator to generate an optical modulation signal; transmitting the light modulation signal to a receiving end through an underwater channel; and controlling the receiving end to perform self-coherent demodulation on the optical modulation signal so as to convert the optical modulation signal into an original optical signal, and converting the original optical signal into an original electric signal through the optical signal detector. The underwater wireless transmission device can convert an electric signal into an optical modulation signal, does not change the intensity of light, only carries information through the phase of the light, is different from the traditional mode of realizing modulation by changing the light intensity and transmits the optical modulation signal to a receiving end through an underwater channel, and the receiving end can eliminate various interferences and losses of the signal in the underwater transmission process when demodulating by using a single photon detector array, increase the signal-to-noise ratio and improve the transmission distance, the anti-interference capability and the stability of underwater wireless transmission.
Description
Technical Field
The invention relates to the field of communication, in particular to an underwater wireless optical communication method and system.
Background
At present, with the continuous progress of human exploration for oceans, underwater activities are rapidly increased. Underwater network technology has also been widely used in marine environments. Existing underwater wireless communication is mainly achieved by sound waves. The bandwidth of the sound wave is limited, the delay is high, and the sound wave is not suitable for high-speed data transmission. Therefore, in underwater short-distance communication links, the way of acoustic wave communication has gradually been replaced by the way of optical wireless communication.
The existing underwater optical communication method is based on amplitude modulation and is easy to be subjected to a flicker effect caused by turbulence. In an optical communication system based on amplitude modulation, the non-linear effect is generated when the change of the amplitude is reflected on the change of the light intensity. In underwater optical wireless communication, information data takes water as a medium, is wirelessly transmitted through light waves, and is received, detected and decoded at a corresponding receiving end. In the existing UWOC (Underwater Wireless Optical Communication) technology, a laser diode LD or a light emitting diode LED is used as a light source, and a photodiode is used as a detector of an Optical signal at a receiving end to convert the received Optical signal into an electrical signal. At a transmitting end, a driving circuit can convert external data into a radio frequency signal and control a light source to generate an optical modulation signal with variable intensity, for example, strong light represents data "1", weak light represents data "0", and at a receiving end, the intensity of the optical modulation signal is directly detected by a detector and converted into a corresponding electrical signal, so that data transmission is realized. However, when water is used as a transmission channel, the optical signal will be severely attenuated during the channel transmission process, for example, water molecules absorb photons, or scattering causes the optical signal to change the propagation direction so that the optical signal cannot reach the receiving end, and the like, thereby distorting the signal received by the receiving end. Therefore, the existing underwater wireless optical communication technology has the defects of poor stability and poor noise interference resistance.
Disclosure of Invention
The invention mainly aims to provide an underwater wireless optical communication method and system, and aims to solve the problems of low signal-to-noise ratio and poor stability of the existing optical communication technology.
In order to achieve the above object, the present invention provides an underwater wireless optical communication system, wherein the underwater wireless optical communication system includes a transmitting end, a channel and a receiving end, and the underwater wireless optical communication method includes the following steps:
controlling the sending end to pre-code the original electric signal and perform phase modulation on the light by using an optical phase modulator so as to generate an optical modulation signal;
transmitting the optical modulation signal to a receiving end through the channel;
and controlling the receiving end to perform self-coherent demodulation on the optical modulation signal so as to convert the optical modulation signal into an original optical signal, and converting the original optical signal into an original electric signal through an optical signal detector.
Optionally, the step of controlling the sending end to precode the original electrical signal and perform phase modulation on the light by using an optical phase modulator to generate the modulated optical signal includes:
controlling an encoding module of the sending end to convert the original electric signal into a Differential Phase Shift Keying (DPSK) electric signal for modulating an optical phase, wherein the original electric signal is generated by overlapping the DPSK electric signal with a DPSK electric signal delayed by a preset period;
and inputting the DPSK electric signal and the light source signal into a phase modulator, and generating an optical modulation signal according to the DPSK electric signal through the phase modulator.
Optionally, the step of controlling the encoding module of the transmitting end to convert the original electrical signal into a differential phase shift keying DPSK electrical signal for modulating an optical phase includes:
controlling an encoding module of the sending end to obtain the original electric signal;
and converting the original electric signal into a DPSK electric signal for modulating the optical phase according to the DPSK coding mode.
Optionally, the step of inputting the DPSK electrical signal and a light source signal into a phase modulator, and generating an optical modulation signal according to the DPSK electrical signal by the phase modulator includes:
the light source signal is input into a phase modulator after being collimated, and the DPSK electric signal for modulating the optical phase is input into the phase modulator;
and controlling the phase modulator to convert the light source signal into an optical modulation signal for modulating the optical phase according to the DPSK electric signal.
Optionally, the step of sending the optical modulation signal to a receiving end through the channel includes:
and outputting the light modulation signal to the channel through a collimator so as to transmit the light modulation signal to a receiving end through the channel, and acquiring the light modulation signal through the collimator arranged at a port of the receiving end.
Optionally, the step of controlling the receiving end to perform an auto-coherent demodulation on the optical modulation signal to convert the optical modulation signal into an original optical signal includes:
controlling a light beam splitting module of the receiving end to convert the light modulation signal into a first light signal and a second light signal;
sending the first optical signal and the second optical signal to an optical coupling module, wherein the difference between the arrival time of the first optical signal and the arrival time of the second optical signal is a preset period;
and interfering the first optical signal and the second optical signal through an optical coupling module, and determining an original optical signal according to the generated interference signal.
Optionally, the step of sending the first optical signal and the second optical signal to an optical coupling module includes:
and sending the first optical signal to an optical coupling module through a first optical path, and sending the second optical signal to the optical coupling module through a second optical path, wherein the length difference between the first optical path and the second optical path is an optical path difference corresponding to a preset period.
Optionally, the step of converting the original optical signal into an original electrical signal by an optical signal detector includes:
and detecting the original optical signal through an optical signal detector, and generating a corresponding original electric signal according to a detection result.
In addition, to achieve the above object, the present invention further provides an underwater wireless optical communication system, including a memory, a processor, and an underwater wireless optical communication program stored in the memory and operable on the processor, wherein: the underwater wireless optical communication program when executed by the processor implements the steps of the underwater wireless optical communication method as described above.
According to the underwater wireless optical communication method and system provided by the embodiment of the invention, the original electric signal at the receiving end is pre-coded, so that the electric signal directly carrying data information can be converted into a DPSK signal carrying information through continuous signals, and the DPSK signal is converted into an optical modulation signal carrying information through phase change through phase modulation. The transmitting end may transmit the optical modulated signal to the receiving end through a channel. The receiving end can perform self-coherent demodulation, i.e. delay superposition processing, on the optical modulation signal, so as to generate an original optical signal corresponding to the original electrical signal through the continuous optical modulation signal. The high-sensitivity single-photon optical signal detector can detect an original optical signal and convert the original optical signal into an original electric signal. Data communication can be realized through the transmission process of the original electric signal from the sending end to the receiving end. Because the data carrier transmitted in the channel is the optical modulation signal, and the optical modulation signal does not directly carry information, but the optical modulation signal needs to be subjected to interference (self-coherent superposition) processing, interference signals or attenuation loss generated in the optical signal transmission process can be filtered in the superposition processing process, the stability and the anti-interference capability in the optical signal transmission process are ensured, and the transmission distance and the stability of wireless transmission are improved.
Drawings
FIG. 1 is a schematic diagram of an apparatus in a hardware operating environment according to an embodiment of the present invention;
FIG. 2 is a schematic flow chart of a first embodiment of the underwater wireless optical communication method according to the present invention;
FIG. 3 is a schematic flow chart of a second embodiment of the underwater wireless optical communication method according to the present invention;
FIG. 4 is a schematic flow chart of a third embodiment of the underwater wireless optical communication method according to the present invention;
FIG. 5 is a schematic flow chart of a fourth embodiment of the underwater wireless optical communication method according to the present invention;
FIG. 6 is a schematic flow chart of a fifth embodiment of the underwater wireless optical communication method according to the present invention;
FIG. 7 is a schematic flow chart of a sixth embodiment of the underwater wireless optical communication method according to the present invention;
FIG. 8 is a flow chart of a seventh embodiment of the underwater wireless optical communication method according to the present invention;
fig. 9 is a schematic flow chart of an eighth embodiment of an underwater wireless optical communication method according to the present invention;
FIG. 10 is a schematic diagram illustrating the process of encoding and demodulating the original electrical signal in the underwater wireless optical communication method according to the present invention;
FIG. 11 is a block diagram of an embodiment of an underwater wireless optical communication system of the present invention;
fig. 12 and 13 are schematic diagrams illustrating device types of a transmitting end and a receiving end in the underwater wireless optical communication method according to the present invention;
fig. 14 is a schematic diagram of interference of two optical signals in the underwater wireless optical communication method according to the present invention.
The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.
Detailed Description
It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
As shown in fig. 1, fig. 1 is a schematic device structure diagram of a hardware operating environment according to an embodiment of the present invention.
The terminal of the embodiment of the invention can be an underwater wireless optical communication system, and mainly comprises a sending end, a channel and a receiving end. It is understood that the channel in the underwater wireless optical communication system may be water, or may be other media such as air.
As shown in fig. 1, the terminal may include: a processor 1001, such as a CPU, a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. Wherein a communication bus 1002 is used to enable connective communication between these components. The user interface 1003 may include a Display screen (Display), an input unit such as a Keyboard (Keyboard), and the optional user interface 1003 may also include a standard wired interface, a wireless interface. The network interface 1004 may optionally include a standard wired interface, a wireless interface (e.g., WI-FI interface). The memory 1005 may be a high-speed RAM memory or a non-volatile memory (e.g., a magnetic disk memory). The memory 1005 may alternatively be a storage device separate from the processor 1001.
Optionally, the transmitting end or the receiving end may further include a camera, a Radio Frequency (RF) circuit, a sensor, an audio circuit, a WiFi module, and the like. Such as light sensors, motion sensors, and other sensors. Specifically, the light sensor may include an ambient light sensor that adjusts the brightness of the display screen based on the ambient light level and a proximity sensor that turns off the display screen and/or backlight when the hardware device is moved to the ear. As one of the motion sensors, the gravity acceleration sensor can detect the magnitude of acceleration in each direction (generally, three axes), can detect the magnitude and direction of gravity when the motion sensor is stationary, and can be used for applications (such as horizontal and vertical screen switching, related games, magnetometer attitude calibration) for recognizing the attitude of hardware equipment, and related functions (such as pedometer and tapping) for vibration recognition; of course, the hardware device may also be configured with other sensors such as a gyroscope, a barometer, a hygrometer, a thermometer, an infrared sensor, and so on, which are not described herein again.
Those skilled in the art will appreciate that the terminal structure shown in fig. 1 is not intended to be limiting and may include more or fewer components than those shown, or some components may be combined, or a different arrangement of components.
As shown in fig. 1, a memory 1005, which is a kind of computer storage medium, may include therein an operating system, a network communication module, a user interface module, and an underwater wireless optical communication program.
In the terminal shown in fig. 1, the network interface 1004 is mainly used for connecting to a backend server and performing data communication with the backend server; the user interface 1003 is mainly used for connecting a client (user side) and performing data communication with the client; and the processor 1001 may be configured to invoke the underwater wireless optical communication program stored in the memory 1005 and perform the following operations:
controlling the sending end to pre-code the original electric signal and perform phase modulation on the light by using an optical phase modulator so as to generate an optical modulation signal;
transmitting the optical modulation signal to a receiving end through the channel;
and controlling the receiving end to perform self-coherent demodulation on the optical modulation signal so as to convert the optical modulation signal into an original optical signal, and converting the original optical signal into an original electric signal through an optical signal detector.
Further, the processor 1001 may invoke an underwater wireless optical communication program stored in the memory 1005, and further perform the following operations:
controlling an encoding module of the sending end to convert the original electric signal into a Differential Phase Shift Keying (DPSK) electric signal for modulating an optical phase, wherein the original electric signal is generated by overlapping the DPSK electric signal with a DPSK electric signal delayed by a preset period;
and inputting the DPSK electric signal and the light source signal into a phase modulator, and generating an optical modulation signal according to the DPSK electric signal through the phase modulator.
Further, the processor 1001 may invoke an underwater wireless optical communication program stored in the memory 1005, and further perform the following operations:
controlling an encoding module of the sending end to obtain the original electric signal;
and converting the original electric signal into a DPSK electric signal for modulating the optical phase according to the DPSK coding mode.
Further, the processor 1001 may invoke an underwater wireless optical communication program stored in the memory 1005, and further perform the following operations:
the light source signal is input into a phase modulator after being collimated, and the DPSK electric signal for modulating the optical phase is input into the phase modulator;
and controlling the phase modulator to convert the light source signal into an optical modulation signal for modulating the optical phase according to the DPSK electric signal.
Further, the processor 1001 may invoke an underwater wireless optical communication program stored in the memory 1005, and further perform the following operations:
and outputting the light modulation signal to the channel through a collimator so as to transmit the light modulation signal to a receiving end through the channel, and acquiring the light modulation signal through the collimator arranged at a port of the receiving end.
Further, the processor 1001 may invoke an underwater wireless optical communication program stored in the memory 1005, and further perform the following operations:
controlling a beam splitting module of the receiving end to convert the optical modulation signal into a first optical signal and a second optical signal;
sending the first optical signal and the second optical signal to an optical coupling module, wherein the difference between the arrival time of the first optical signal and the arrival time of the second optical signal is a preset period;
and interfering the first optical signal and the second optical signal through an optical coupling module, and determining an original optical signal according to the generated interference signal.
Further, the processor 1001 may invoke an underwater wireless optical communication program stored in the memory 1005, and further perform the following operations:
and sending the first optical signal to an optical coupling module through a first optical path, and sending the second optical signal to the optical coupling module through a second optical path, wherein the length difference between the first optical path and the second optical path is an optical path difference corresponding to a preset period.
Further, the processor 1001 may invoke an underwater wireless optical communication program stored in the memory 1005, and further perform the following operations:
and detecting the original optical signal through an optical signal detector, and generating a corresponding original electric signal according to a detection result.
The specific embodiment of the present invention applied to the underwater wireless optical communication system is basically the same as the following embodiments of the underwater wireless optical communication method, and is not described herein again.
Referring to fig. 2, fig. 2 is a schematic flow chart of a first embodiment of the underwater wireless optical communication method of the present invention, wherein the underwater wireless optical communication method includes the following steps:
step S10, controlling the sending terminal to pre-code the original electric signal and to modulate the phase of the light by the optical phase modulator to generate the light modulation signal;
in this embodiment, the underwater wireless optical communication system includes a transmitting end, a receiving end, and a channel. When the system is applied to underwater wireless communication, the channel may be water.
The transmitting end and the receiving end are separated by a certain distance, and the medium between the transmitting end and the receiving end is water. It is understood that the attenuation rate of light at different wavelengths is not the same as the water quality changes. Generally, the attenuation rate of light waves with the wavelength between 400nm and 550nm in most water is small, so that the light serving as a data carrier in a channel can adopt a blue-green wave band in visible light, so that the attenuation coefficient of the light in the process of propagating in the channel is as small as possible.
A transmitting end in the system may receive an original electrical signal to be transmitted to a receiving end, and the original electrical signal may be transmitted to the transmitting end in a binary coding manner. After the sending end acquires the original electrical signal, the sending end may perform precoding on the original electrical signal to convert the original electrical signal into a DPSK signal in which information is carried by a continuous electrical signal. The DPSK signal and the original electrical signal may be mutually encoded and converted, and each two adjacent electrical signals in the DPSK signal may correspond to one electrical signal of the original electrical signals. After the original electrical signal is converted into a DPSK signal through pre-coding at the transmitting end, the DPSK signal may be phase-modulated to generate an optical modulation signal corresponding to the DPSK signal. The optical modulation signal can carry and transmit the signal through the change of the phase, and the specific phase corresponds to the signal type in the original electric signal. It will be appreciated that where the original electrical signal is a binary encoded signal, the phase of the optical modulation signal may be set to 0 and pi, corresponding to 0 and 1 in the binary encoding, respectively.
Step S20, the modulated optical signal is sent to a receiving end through the channel;
after the original electric signal is converted into an optical modulation signal carrying data information through a phase, the optical modulation signal can be sent to a receiving end through a channel arranged between the sending end and the receiving end. It can be understood that the transmission path of light in the channel is generally straight, but because the light propagates in water and has scattering phenomenon, and part of scattered light deviates from the optical axis, the receiving end may be in the direction of the optical axis from which the laser beam is emitted, or in other positions where the scattered light can be received.
Step S30, controlling the receiving end to perform self-coherent demodulation on the optical modulation signal, so as to convert the optical modulation signal into an original optical signal, and converting the original optical signal into an original electrical signal by using an optical signal detector.
After a receiving end receives an optical modulation signal transmitted by a transmitting end through a channel, the optical modulation signal needs to be subjected to self-coherent demodulation so as to be converted into an original optical signal. The phase information in the optical modulation signal corresponds to the coding information of the pre-coded DPSK signal, and the self-coherent demodulation of the optical modulation signal means that the optical modulation signal is delayed and the delayed optical modulation signal and the original optical modulation signal are subjected to superposition interference processing.
It can be understood that, since the precoded DPSK signal can implement inverse coding to regenerate the original electrical signal through the same self-delaying and superposition operations, the modulated optical signal can generate the original optical signal corresponding to the original electrical signal through the delay processing and the superposition interference with the original modulated optical signal.
After the original optical signal is generated, the original optical signal can be sent to an optical signal detector for detection, and the optical signal detector can convert the received original optical signal into an original electric signal according to the intensity of the received original optical signal and output the original electric signal, so that the transmission process of the original electric signal from a sending end to a receiving end is realized.
It should be noted that, in the optical modulation signal transmitted from the transmitting end to the receiving end, the manner of carrying information is phase change of the optical wave. And the original optical signal generated according to the optical modulation signal carries information in the mode of the intensity of the optical wave. For example, when the original electrical signal is encoded in a binary manner, the generated original optical signal may be a transmission photon and a non-transmission photon, that is, when the optical signal detector detects a photon, it indicates that the original optical signal corresponds to a 1 in the original electrical signal, and when the optical signal detector does not detect a photon, it indicates that the original optical signal corresponds to a 0 in the original electrical signal.
In this embodiment, by pre-coding the original electrical signal at the receiving end, the electrical signal directly carrying information can be converted into a DPSK signal carrying information by a continuous signal, and the DPSK signal can be converted into an optical modulation signal carrying information by phase variation by phase modulation. The transmitting end may transmit the optical modulated signal to the receiving end through a channel. The receiving end can perform self-coherent demodulation, i.e. delay superposition processing, on the optical modulation signal, so as to generate an original optical signal corresponding to the original electrical signal through the continuous optical modulation signal. The original optical signal can be detected by an optical signal detector after being generated, and the original optical signal is converted into an original electric signal. Data communication can be realized through the transmission process of the original electric signal from the sending end to the receiving end. Because the data carrier of transmission is the light modulation signal in the channel, and the light modulation signal does not directly carry information, but need carry out the autocorrelation stack processing with the light modulation signal, can filter the interfering signal or the decay loss that produce in the light signal transmission course in the stack processing procedure, guarantee stability and the interference killing feature in the light signal transmission course, promote wireless transmission's transmission distance and stability.
It should be noted that, at present, all modulation modes of underwater optical communication carry information through amplitude, and are susceptible to a flicker effect caused by turbulence. In an amplitude modulation based optical communication system, a nonlinear effect is generated when a change in amplitude is reflected on a change in light intensity. Compared with the prior art, the light intensity in the phase modulation communication mode is kept unchanged, and the nonlinear effect is avoided. In addition, the phase modulation and the amplitude modulation are not in the same dimension, and the one dimension of the amplitude modulation is changed into the two dimensions of the phase modulation, so that the possibility of high-order modulation and high spectrum efficiency can be opened.
Further, referring to fig. 3, fig. 3 is a flowchart illustrating a second embodiment of the underwater wireless optical communication method according to the present invention, based on the embodiment shown in fig. 2, in step S10, the step of controlling the sending end to precode the original electrical signal and perform phase modulation on the light by using the optical phase modulator to generate the optical modulation signal includes:
step S11, controlling the encoding module of the transmitting end to convert the original electrical signal into a Differential Phase Shift Keying (DPSK) electrical signal for modulating an optical phase, wherein the original electrical signal is generated by superimposing the DPSK electrical signal and a DPSK electrical signal delayed by a preset period;
and step S12, inputting the DPSK electric signal and the light source signal into a phase modulator, and generating an optical modulation signal according to the DPSK electric signal through the phase modulator.
In this embodiment, the sending end may perform precoding on the original electrical signal, and then perform phase modulation on the precoded DPSK signal. The transmitting end is internally provided with an encoding module, and when the transmitting end receives an original electric signal, the original electric signal can be converted into a Differential Phase Shift Keying (DPSK) electric signal for modulating the optical phase through the encoding module. Namely, the DPSK electrical signal may be delayed by a preset period and superimposed with the original DPSK electrical signal, and the corresponding original electrical signal may be determined according to the superimposed DPSK electrical signal.
As shown in fig. 10, when the preset period is set to one bit, i.e., one period, each of the original electrical signals corresponds to two adjacent DPSK electrical signals, respectively. When a certain DPSK electric signal is the same as the previous DPSK electric signal, the original electric signal corresponding to the DPSK electric signal is 1, and if the certain DPSK electric signal is different from the previous DPSK electric signal, the original electric signal corresponding to the DPSK electric signal is 0. After converting the original electrical signal into a DPSK electrical signal according to the precoding rule, the DPSK electrical signal and the laser signal provided by the light source may be input to a phase modulator.
The DPSK signal after precoding can be input into a function generator to generate a point modulation signal, the function generator outputs corresponding modulation voltage to a phase modulator according to the point modulation signal, and the phase modulator can convert a laser signal into an optical modulation signal with the phase changing from 0 to pi according to different modulation voltages. Compared with the prior art in which information is carried by the output intensity of the optical signal, the phase-modulated optical signal converted by the phase modulator is changed only in phase, and the light intensity of the optical signal can be always kept as a strong optical signal, so that distortion caused by absorption or scattering and other phenomena in the channel transmission process when the signal is transmitted to a receiving end is avoided.
Further, referring to fig. 4, fig. 4 is a schematic flowchart of a third embodiment of the underwater wireless optical communication method of the present invention, based on the embodiment shown in fig. 3, in step S11, the step of controlling the encoding module at the transmitting end to convert the original electrical signal into a DPSK electrical signal for modulating an optical phase includes:
step S111, controlling the encoding module of the transmitting end to obtain the original electric signal;
step S112, converting the original electrical signal into a DPSK electrical signal for modulating the optical phase according to the DPSK encoding method.
In this embodiment, after receiving the original electrical signal, the sending end may send the original electrical signal to the encoding module for precoding, so as to convert the original electrical signal into a DPSK electrical signal.
After the encoding module acquires the original electrical signal, the DPSK electrical signal corresponding to the original electrical signal may be generated according to the original electrical signal and the generated DPSK electrical signal. As shown in fig. 10, when the preset period is set to be one period, the pre-coding rule of the coding module may be that an original electrical signal and a DPSK electrical signal that has been generated before are obtained, and if the original electrical signal is 1, a DPSK electrical signal that is newly generated and corresponds to the original electrical signal is the same as the DPSK electrical signal that has been generated before; if the original electrical signal is 0, the newly generated DPSK electrical signal corresponding to the original electrical signal is opposite to the previous generated DPSK electrical signal. That is, when the original electrical signal is 1, the previous DPSK electrical signal is 1, and the new DPSK electrical signal is also 1; the previous DPSK electrical signal is 0, then the new DPSK electrical signal is also 0. When the original electrical signal is 0, the previous DPSK electrical signal is 1, and the new DPSK electrical signal is 0; the former DPSK electrical signal is 0, and the new DPSK electrical signal is 1.
It is to be understood that the encoding module may implement the encoding process of converting the original electrical signal into the DPSK electrical signal by setting an encoding circuit or a function generator, and may also implement other devices capable of implementing differential encoding. Specifically, the encoding module can implement the pre-encoding function of the original electrical signal through the combination of the PC application and the function generator.
In the above coding rule, an original electrical signal directly containing data information is converted into a DPSK electrical signal, and an optical modulation signal is generated from the DPSK electrical signal. When the optical modulation signal is transmitted in a channel, even if the optical modulation signal is acquired by other third parties, because the light intensity does not carry information, when the third party does not predetermine the coding rule of converting the DPSK electric signal into the original electric signal, the original electric signal cannot be obtained through the compiling of the optical modulation signal, namely, the optical modulation signal carrying data is equivalent to encrypted transmission in the transmission process, so that the safety and the confidentiality in the information data transmission process can be improved.
Further, referring to fig. 5, fig. 5 is a schematic flowchart of a fourth embodiment of the underwater wireless optical communication method of the present invention, based on the embodiment shown in fig. 3, the step S12 of inputting the DPSK electrical signal and the light source signal into a phase modulator, and generating an optical modulation signal according to the DPSK electrical signal by the phase modulator includes:
step S121, collimating the light source signal, inputting the collimated light source signal into a phase modulator, and inputting the DPSK electric signal for modulating the optical phase into the phase modulator;
and step S122, controlling the phase modulator to convert the light source signal into an optical modulation signal for modulating the optical phase according to the DPSK electric signal.
In this embodiment, the phase modulator itself does not generate the light source signal, which may be a predetermined laser signal emitted by the light source. The laser signal may be collimated by a collimating lens disposed between the light source and the phase modulator, and the collimated laser signal is input to the phase modulator such that the laser signal reduces scattering. After receiving the DPSK signal, the phase modulator can modulate the laser signal into an optical modulation signal carrying data information through phase change of an optical domain, and keep the light intensity unchanged.
The light source can be a narrow linewidth solid laser, the laser wavelength emitted by the light source can be 532nm, the linewidth is within 1MHz, and the light source has good beam quality, beam quality M2The factor may be 1.1.
It will be appreciated that the light source may also be configured as other narrow linewidth lasers such as semiconductor lasers, fiber lasers, gas lasers, etc., or may be configured as other types of lasers such as fiber output lasers or spatial light output lasers. The phase modulator may be a fiber coupling phase modulator, a spatial light coupling phase modulator, or other non-fiber coupling phase modulators.
Further, referring to fig. 6, fig. 6 is a flowchart illustrating a fifth embodiment of the underwater wireless optical communication method according to the present invention, based on the embodiment shown in fig. 2, in step S20, the step of sending the optical modulation signal to a receiving end through the channel includes:
step S21, outputting the optical modulation signal to the channel through a collimator, so as to send the optical modulation signal to a receiving end through the channel, and acquiring the optical modulation signal through a collimator disposed at a port of the receiving end.
In this embodiment, the port of the transmitting end and the port of the receiving end may both be provided with collimators to collimate light of the passing optical modulation signal, thereby reducing the scattering phenomenon of the optical signal. The collimator can be used for adjusting the laser beam and enabling the laser to be emitted in parallel to achieve long-distance transmission. The optical fiber collimating lens can be formed by a single lens or a combination of a plurality of lenses, and the type can be a space light type directly collimating space light, or an optical fiber interface type with an optical fiber joint and collimating laser output by an optical fiber. The sending end can output the generated optical modulation signal to a channel through a collimator, and send the optical modulation signal to the receiving end through the channel. Because the energy of the optical modulation signal is attenuated after the optical modulation signal is transmitted through a medium in a channel, in order to improve the optical power of the received optical modulation signal as much as possible, a collimator can be arranged at a port of a receiving end, and the optical modulation signal is subjected to light beam collection through the collimator, so that the optical modulation signal is ensured to have higher optical power after being transmitted through the channel.
Further, referring to fig. 7, fig. 7 is a flowchart illustrating a sixth embodiment of the underwater wireless optical communication method of the present invention, based on the embodiment shown in fig. 2, in step S30, the step of controlling the receiving end to perform self-coherent demodulation on the optical modulation signal, so as to convert the optical modulation signal into an original optical signal, and convert the original optical signal into an original electrical signal by using the optical signal detector includes:
step S31, controlling the beam splitting module at the receiving end to convert the optical modulation signal into a first optical signal and a second optical signal;
step S32, sending the first optical signal and the second optical signal to an optical coupling module, where the arrival time of the first optical signal and the arrival time of the second optical signal differ by a preset period;
step S33, interfering the first optical signal and the second optical signal through an optical coupling module, and determining an original optical signal according to the generated interference signal;
step S34, converting the original optical signal into an original electrical signal by the optical signal detector.
In this embodiment, after receiving the optical modulation signal transmitted through the channel, the receiving end may separate the optical modulation signal into a first optical signal and a second optical signal through the optical splitting module. And the first optical signal and the second optical signal are respectively sent to the optical coupling module.
The optical splitting module may split the optical modulation signal into two optical signals according to an equal ratio of signal optical power, that is, the phases and intensities of the first optical signal and the second optical signal are completely the same. However, the first optical signal and the second optical signal are sent to the optical coupling module through different transmission paths, that is, the optical paths of the two optical signals sent to the optical coupling module are different, so that the phase difference between the first optical signal and the second optical signal received by the optical coupling module is a preset period.
The optical coupling module may interfere the first optical signal and the second optical signal after receiving the first optical signal and the second optical signal, and generate an interference signal. Referring to fig. 10 and 14, the preset period is set to 1 bit, after two optical signals different by the preset period interfere with each other, the interference signal at each position is a phase superposition of the two optical signals, and if the phases of the two optical signals at the position are the same, for example, the phases are both 0 or both pi, the superposed interference signal may be determined to be 1; if the two optical signals have different phases at the position, for example, one of the two optical signals has a phase of 0 and the other optical signal has a phase of pi, the superimposed interference signal can be determined to be 0. The data information carried in the DPSK optical signal can be determined by delaying the received optical modulation signal, coupling the delayed optical modulation signal with the original optical modulation signal and superposing the phases.
And according to the generated interference signal, the corresponding original optical signal can be sent to the optical signal detector. When the generated interference signal is 1, the optical signal can be projected to the optical signal detector; and when the generated interference signal is 0, the optical signal is cut off. When the optical signal detector receives the original optical signal, the original electrical signal can be determined to be 1, and a corresponding original electrical signal is output; and when the original optical signal is not received by the optical signal detector, the original electrical signal can be determined to be 0, and a corresponding original electrical signal is output.
It should be noted that, because the optical signal detector only detects whether a photon is received, and does not detect the phase information of the optical signal, when the interference signal is 1, the optical coupling module may send one of the two optical signals to the optical signal detector, or may send the two optical signals to the optical signal detector after coupling, so as to improve the intensity of the optical signal, and enable the optical signal detector to easily detect the optical signal.
Further, referring to fig. 8, fig. 8 is a flowchart illustrating a seventh embodiment of the underwater wireless optical communication method according to the present invention, based on the embodiment shown in fig. 7, in step S32, the step of sending the first optical signal and the second optical signal to the optical coupling module includes:
step S321, sending the first optical signal to the optical coupling module through a first optical path, and sending the second optical signal to the optical coupling module through a second optical path, where a length difference between the first optical path and the second optical path is an optical path difference corresponding to a preset period.
In this embodiment, the optical path is a propagation path of light, and may be in a free space (air/vacuum, etc.), or may be an optical fiber or other types of optical waveguides. After the receiving end separates the optical modulation signal into a first optical signal and a second optical signal with the same phase and intensity through the beam splitting module, the first optical signal can be sent to the optical coupling module through the first optical path, and the second optical signal can be sent to the optical coupling module through the second optical path. The length difference between the first optical path and the second optical path may be an optical path difference corresponding to a preset period, and when the first optical path is short and the second optical path is long, after propagation through the optical paths, the phase of the second optical signal relative to the first optical signal is delayed, and at this time, the optical coupling module couples the first optical signal and the second optical signal to realize self-coherent interference of the optical signal and the delayed optical signal.
When the preset period is one period, the optical path difference of the two optical signals should be Length = Time × c/n, where Time is the delay Time, c is the optical speed 3x10^8m/s, and n is the refractive index 1.5 in the optical fiber. In the scheme, the preset communication rate can be 200Mbps, the time length of one period is 5ns, the time delay of one period generated by two optical signals can be calculated, and the optical path difference is 1 meter. The difference in length between the first optical path and the second optical path can be set to 1 m.
It is understood that when the light source is set as a space light, the light coupling module can be replaced by a space light coupling device. As shown in fig. 12 and 13, in the underwater wireless optical communication system, the types of the transceiver devices do not affect each other. Fig. 12 is a schematic diagram of a transmitting end using a spatial light device or an optical fiber device, and fig. 13 is a schematic diagram of a receiving end using a spatial light device or an optical fiber device. Namely, whether the transmitting end adopts space light or an optical fiber device, the receiving end can adopt space light or an optical fiber device. The laser light source used in the existing underwater wireless optical communication technology is 400nm-600nm wavelength of visible light band, which is different from 850/1310/1550nm of infrared light band of space optical communication and optical fiber communication.
Further, referring to fig. 9, fig. 9 is a schematic flowchart of an eighth embodiment of the underwater wireless optical communication method of the present invention, based on the embodiment shown in fig. 7, in step S34, the step of converting the original optical signal into an original electrical signal by the optical signal detector includes:
step S341, detecting the original optical signal by the optical signal detector, and generating a corresponding original electrical signal according to the detection result.
In this embodiment, after the optical coupling module couples the two optical signals, if the generated interference signal is 1, the optical coupling module may send the optical signal to the optical signal detector, and if the generated interference signal is 0, the optical coupling module may cut off the optical signal. The optical signal detector can be a balanced type photoelectric detector, the Silicon photomultiplier or the SPAD (Single Photon Avalanche Diode) has Single Photon detection capability, even if the optical signal sent by the optical coupling module is extremely weak, the SPAD can also detect Single Photon, so that the original optical signal can be accurately converted into the original electric signal when the optical signal is weaker, the power tolerance of the underwater wireless optical communication system is improved, and the transmission distance of wireless communication can also be improved.
The optical signal detector can also be an Avalanche Photo Diode (APD), a PIN photodiode and the like, and the production cost can be reduced compared with a single Photon Avalanche Diode.
In addition, the invention also provides a computer readable storage medium, on which the underwater wireless optical communication program is stored. The computer-readable storage medium may be the Memory 20 in the terminal in fig. 1, and may also be at least one of a ROM (Read-Only Memory)/RAM (Random Access Memory), a magnetic disk, and an optical disk, and the computer-readable storage medium includes several instructions for causing an underwater wireless optical communication system with a processor to execute the underwater wireless optical communication method according to the embodiments of the present invention.
Referring to fig. 11, the present invention further provides an underwater wireless optical communication system, which includes a transmitting end 10, a channel 20, and a receiving end 30. The transmitting end 10 includes a light source 11, a phase modulator 12, an encoding module 13, a collimating lens 15 and a collimator 14, and the receiving end 30 includes a collimator 14, a beam splitting module 31, an optical coupling module 32 and an optical signal detector 33.
After the original electrical signal is received by the transmitting end 10, the original electrical signal may be precoded by the encoding module 13 to generate a DPSK electrical signal, and the DPSK electrical signal is sent to the phase modulator 12. The phase modulator 12 may also receive a light source 11 signal emitted by the light source 11, where the light source 11 signal may be a laser signal and is input to the phase modulator 12 through the collimating lens 15. The phase modulator 12 may perform phase modulation on the laser signal according to the DPSK electrical signal to generate an optical modulation signal corresponding to the DPSK signal. The modulated optical signal may be transmitted to a receiving end 30 via a channel 20. Collimators 14 are provided on both the input side and the output side of the channel 20 to concentrate the optical modulation signal and prevent the light intensity from being reduced due to scattering of the optical signal. After receiving the optical modulation signal, the receiving end 30 may split the optical modulation signal into two identical optical signals, i.e. a first optical signal and a second optical signal, by the beam splitting module 31. The first optical signal and the second optical signal are input to the optical coupling module 32 through optical fibers with different lengths, so that there is a delay between the two optical signals received by the optical coupling module 32, for example, the second optical signal is delayed by one period relative to the first optical signal. The optical coupling module 32 is configured to obtain a corresponding interference signal by interfering the first optical signal with the delayed second optical signal, and send the original optical signal to the optical signal detector 33 according to the interference signal. The optical signal detector 33 determines that the original optical signal is 0 or 1 according to whether the photon is received, that is, the optical signal detector 33 determines that the original optical signal is 1 when the photon is received, and determines that the original optical signal is 0 when the photon is not received, and regenerates the original electrical signal according to the original optical signal to output, so as to implement the communication transmission process of the original electrical signal from the transmitting end 10 to the receiving end 30 through the channel 20.
It is to be understood that throughout the description of the present specification, reference to the term "one embodiment", "another embodiment", "other embodiments", or "first through nth embodiments", etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or system. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or system that comprises the element.
The above-mentioned serial numbers of the embodiments of the present invention are merely for description and do not represent the merits of the embodiments.
Through the above description of the embodiments, those skilled in the art will clearly understand that the method of the above embodiments can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware, but in many cases, the former is a better implementation manner. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium (e.g., ROM/RAM, magnetic disk, optical disk) as described above and includes instructions for enabling a terminal device (e.g., a mobile phone, a computer, a server, an air conditioner, or a network device) to execute the method according to the embodiments of the present invention.
The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.
Claims (9)
1. An underwater wireless optical communication method is applied to an underwater wireless optical communication system, the underwater wireless optical communication system comprises a sending end, a channel and a receiving end, and the underwater wireless optical communication method comprises the following steps:
controlling the sending end to pre-code the original electric signal and perform phase modulation on the light by using an optical phase modulator so as to generate an optical modulation signal;
transmitting the optical modulation signal to a receiving end through the channel;
and controlling the receiving end to perform self-coherent demodulation on the optical modulation signal so as to convert the optical modulation signal into an original optical signal, and converting the original optical signal into an original electric signal through an optical signal detector.
2. The underwater wireless optical communication method as claimed in claim 1, wherein the step of controlling the transmitting terminal to precode the original electric signal and to phase-modulate the light using the optical phase modulator to generate the light-modulated signal comprises:
controlling an encoding module of the sending end to convert the original electric signal into a Differential Phase Shift Keying (DPSK) electric signal for modulating an optical phase, wherein the original electric signal is generated by overlapping the DPSK electric signal with a DPSK electric signal delayed by a preset period;
and inputting the DPSK electric signal and the light source signal into a phase modulator, and generating an optical modulation signal according to the DPSK electric signal through the phase modulator.
3. The underwater wireless optical communication method according to claim 2, wherein the step of controlling the encoding module of the transmitting end to convert the original electrical signal into a Differential Phase Shift Keying (DPSK) electrical signal for modulating optical phase comprises:
controlling an encoding module of the sending end to obtain the original electric signal;
and converting the original electric signal into a DPSK electric signal for modulating the optical phase according to the DPSK coding mode.
4. The underwater wireless optical communication method according to claim 2, wherein the step of inputting the DPSK electrical signal and a light source signal into a phase modulator, and generating an optical modulation signal from the DPSK electrical signal by the phase modulator comprises:
the light source signal is input into a phase modulator after being collimated, and the DPSK electric signal for modulating the optical phase is input into the phase modulator;
and controlling the phase modulator to convert the light source signal into an optical modulation signal for modulating the optical phase according to the DPSK electric signal.
5. The underwater wireless optical communication method of claim 1, wherein the step of transmitting the optically modulated signal to a receiving end through the channel comprises:
and outputting the light modulation signal to the channel through a collimator so as to transmit the light modulation signal to a receiving end through the channel, and acquiring the light modulation signal through the collimator arranged at a port of the receiving end.
6. The underwater wireless optical communication method as claimed in claim 1, wherein the step of controlling the receiving terminal to perform an autocorrelation demodulation on the optical modulation signal to convert the optical modulation signal into an original optical signal comprises:
controlling a beam splitting module of the receiving end to convert the optical modulation signal into a first optical signal and a second optical signal;
sending the first optical signal and the second optical signal to an optical coupling module, wherein the difference between the arrival time of the first optical signal and the arrival time of the second optical signal is a preset period;
and interfering the first optical signal and the second optical signal through an optical coupling module, and determining an original optical signal according to the generated interference signal.
7. The underwater wireless optical communication method of claim 6, wherein the step of sending the first optical signal and the second optical signal to an optical coupling module comprises:
and sending the first optical signal to an optical coupling module through a first optical path, and sending the second optical signal to the optical coupling module through a second optical path, wherein the length difference between the first optical path and the second optical path is an optical path difference corresponding to a preset period.
8. The underwater wireless optical communication method of claim 6, wherein the step of converting the original optical signal into an original electrical signal by an optical signal detector comprises:
and detecting the original optical signal through an optical signal detector, and generating a corresponding original electric signal according to a detection result.
9. An underwater wireless optical communication system comprising a memory, a processor and an underwater wireless optical communication program stored on the memory and operable on the processor, wherein: the underwater wireless optical communication program when executed by the processor implements the steps of the underwater wireless optical communication method as claimed in any one of claims 1 to 8.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011618350.6A CN112291019A (en) | 2020-12-31 | 2020-12-31 | Underwater wireless optical communication method and system |
| PCT/CN2021/072242 WO2022141676A1 (en) | 2020-12-31 | 2021-01-15 | Underwater wireless optical communication method and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011618350.6A CN112291019A (en) | 2020-12-31 | 2020-12-31 | Underwater wireless optical communication method and system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112291019A true CN112291019A (en) | 2021-01-29 |
Family
ID=74425288
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011618350.6A Pending CN112291019A (en) | 2020-12-31 | 2020-12-31 | Underwater wireless optical communication method and system |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN112291019A (en) |
| WO (1) | WO2022141676A1 (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111313981A (en) * | 2020-02-11 | 2020-06-19 | 鹏城实验室 | Underwater wireless optical communication method, device and system |
| CN112968736A (en) * | 2021-02-02 | 2021-06-15 | 浙江大学 | End-to-end OFDM underwater high-speed wireless optical communication system and method based on self-supervision deep learning |
| CN113132016A (en) * | 2021-04-13 | 2021-07-16 | 西安邮电大学 | Dual-wavelength underwater wireless optical communication method and system |
| CN113438031A (en) * | 2021-05-26 | 2021-09-24 | 上海季丰电子股份有限公司 | Dual-frequency optical communication system |
| CN114337844A (en) * | 2022-03-07 | 2022-04-12 | 鹏城实验室 | Phase compensation method, device, terminal and storage medium |
| CN114401044A (en) * | 2021-12-20 | 2022-04-26 | 武汉邮电科学研究院有限公司 | Underwater optical communication transmitting method and transmitting system |
| CN117749266A (en) * | 2024-02-21 | 2024-03-22 | 国家海洋技术中心 | Underwater wireless optical communication awakening method and device |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101980460A (en) * | 2010-10-29 | 2011-02-23 | 武汉光迅科技股份有限公司 | Monolithically integrated multi-wavelength differential quadrature phase shift keying (DQPSK) demodulator and manufacturing method thereof |
| CN109375323A (en) * | 2018-11-23 | 2019-02-22 | 中国船舶重工集团公司第七0五研究所 | A kind of low cost infrared band underwater wireless optical communication apparatus |
| CN209134429U (en) * | 2018-10-29 | 2019-07-19 | 中国电子科技集团公司电子科学研究院 | Phase decoding device and quantum key distribution system based on 90 degree of welding difference control |
| CN110730039A (en) * | 2019-09-19 | 2020-01-24 | 华侨大学 | Method for improving wireless optical communication performance under strong flow running water |
| CN111313981A (en) * | 2020-02-11 | 2020-06-19 | 鹏城实验室 | Underwater wireless optical communication method, device and system |
| US20200266902A1 (en) * | 2016-08-25 | 2020-08-20 | King Abdullah University Of Science And Technology | Systems and methods for underwater illumination, survey, and wireless optical communications |
| CN112039671A (en) * | 2020-09-26 | 2020-12-04 | 神盾迅波(北京)量子科技发展有限公司 | Efficient quantum key distribution system and method |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100592878B1 (en) * | 2003-12-18 | 2006-06-23 | 한국전자통신연구원 | Device and method of electrically band-limited optical dpsk |
| CN101056155B (en) * | 2007-05-21 | 2012-12-12 | 湖南大学 | Optical source concentrated wave division multiplexing passive optical network for simultaneously generating the DPSK and OOK signals |
-
2020
- 2020-12-31 CN CN202011618350.6A patent/CN112291019A/en active Pending
-
2021
- 2021-01-15 WO PCT/CN2021/072242 patent/WO2022141676A1/en active Application Filing
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101980460A (en) * | 2010-10-29 | 2011-02-23 | 武汉光迅科技股份有限公司 | Monolithically integrated multi-wavelength differential quadrature phase shift keying (DQPSK) demodulator and manufacturing method thereof |
| US20200266902A1 (en) * | 2016-08-25 | 2020-08-20 | King Abdullah University Of Science And Technology | Systems and methods for underwater illumination, survey, and wireless optical communications |
| CN209134429U (en) * | 2018-10-29 | 2019-07-19 | 中国电子科技集团公司电子科学研究院 | Phase decoding device and quantum key distribution system based on 90 degree of welding difference control |
| CN109375323A (en) * | 2018-11-23 | 2019-02-22 | 中国船舶重工集团公司第七0五研究所 | A kind of low cost infrared band underwater wireless optical communication apparatus |
| CN110730039A (en) * | 2019-09-19 | 2020-01-24 | 华侨大学 | Method for improving wireless optical communication performance under strong flow running water |
| CN111313981A (en) * | 2020-02-11 | 2020-06-19 | 鹏城实验室 | Underwater wireless optical communication method, device and system |
| CN112039671A (en) * | 2020-09-26 | 2020-12-04 | 神盾迅波(北京)量子科技发展有限公司 | Efficient quantum key distribution system and method |
Non-Patent Citations (1)
| Title |
|---|
| 张慧颖 等: "空间光DPSK发射与自相干接收***实验", 《激光与红外》 * |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111313981A (en) * | 2020-02-11 | 2020-06-19 | 鹏城实验室 | Underwater wireless optical communication method, device and system |
| CN112968736A (en) * | 2021-02-02 | 2021-06-15 | 浙江大学 | End-to-end OFDM underwater high-speed wireless optical communication system and method based on self-supervision deep learning |
| CN113132016A (en) * | 2021-04-13 | 2021-07-16 | 西安邮电大学 | Dual-wavelength underwater wireless optical communication method and system |
| CN113438031A (en) * | 2021-05-26 | 2021-09-24 | 上海季丰电子股份有限公司 | Dual-frequency optical communication system |
| CN114401044A (en) * | 2021-12-20 | 2022-04-26 | 武汉邮电科学研究院有限公司 | Underwater optical communication transmitting method and transmitting system |
| CN114401044B (en) * | 2021-12-20 | 2023-07-25 | 武汉邮电科学研究院有限公司 | Underwater optical communication transmitting method and transmitting system |
| CN114337844A (en) * | 2022-03-07 | 2022-04-12 | 鹏城实验室 | Phase compensation method, device, terminal and storage medium |
| CN117749266A (en) * | 2024-02-21 | 2024-03-22 | 国家海洋技术中心 | Underwater wireless optical communication awakening method and device |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2022141676A1 (en) | 2022-07-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112291019A (en) | Underwater wireless optical communication method and system | |
| Oubei et al. | 2.3 Gbit/s underwater wireless optical communications using directly modulated 520 nm laser diode | |
| Zhu et al. | Transmission of dual-chirp microwave waveform over fiber with compensation of dispersion-induced power fading | |
| Torres-Ferrera et al. | Impact of the overall electrical filter shaping in next-generation 25 and 50 Gb/s PONs | |
| Singh et al. | Performance comparison of high-speed long-reach mode division multiplexing-based radio over free space optics transmission system using different modulation formats under the effect of atmospheric turbulence | |
| Mirza et al. | All-optical generation and transmission of multiple ultrawideband signals over free space optical link | |
| Xie et al. | 960-km SSMF transmission of 105.7-Gb/s PDM 3-PAM using directly modulated VCSELs and coherent detection | |
| Zhang et al. | Phase-coded microwave signal generation based on a single electro-optical modulator and its application in accurate distance measurement | |
| Mirza et al. | A full duplex ultrawideband over free‐space optics architecture based on polarization multiplexing and wavelength reuse | |
| US9906311B1 (en) | Transceivers and receivers for quantum key distribution and methods pertaining thereto | |
| JP2020505634A (en) | Optical transmitter | |
| Baiwa et al. | Performance analysis of FSO system for advanced modulation formats under different weather conditions | |
| Zhang et al. | Prototype system for underwater wireless optical communications employing orbital angular momentum multiplexing | |
| Singh et al. | Investigation of 340-Gbps terrestrial FSO link incorporating spectral-efficient DP-QPSK-PolSK hybrid modulation scheme | |
| Malathy et al. | Modeling and performance investigation of 4× 20 Gbps underwater optical wireless communication link incorporating space division multiplexing of Hermite Gaussian modes | |
| Mangrio et al. | Effects of modulation scheme on experimental setup of RGB LEDs based underwater optical communication | |
| Kumar et al. | Design of multi-beam free space optical communication system for mitigation of atmospheric and geometric nonlinearities | |
| Kandouci | Investigation of Jervol water types properties effects on underwater optical wireless OCDMA system performances for different modulation techniques | |
| Poirier et al. | Undersea laser communication using polarization and wavelength modulation | |
| US20170214465A1 (en) | Multimode Elliptical Core Optical Data Transmission | |
| Sabri et al. | Last mile access-based FSO and VLC systems | |
| Khallaf et al. | Hybrid two-level MPPM–MDPSK modulation for high-speed optical communication networks | |
| Yi et al. | Improved slow-light performance of 10 Gb/s NRZ, PSBT and DPSK signals in fiber broadband SBS | |
| Farooq et al. | BER analysis of OOK and DPSK schemes in gamma-gamma turbulence channel with PIN and APD photodetector | |
| Gafur et al. | Comparison of coherent optical transmission systems performance by DP-QAM levels |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210129 |