Multi-emission multi-receiving-end underwater visible light communication device and system

Abstract

The invention provides a multi-transmitting and multi-receiving-end underwater visible light communication device and system, relates to the technical field of visible light communication, is used for relieving the technical problem of low alignment degree of transmitting ends and receiving ends of a visible light communication system in an underwater complex environment, and can realize underwater efficient information transmission. The device comprises an information input end, a visible light emitting end, a visible light receiving end and an information output end, the visible light emitting end comprises a driving power supply, an LD light emitter, an LDMOS series driving module and an arbitrary waveform generator, and the driving power supply and the LDMOS series driving module are connected with the LD light emitter; the LDMOS series drive module is used for controlling the on-off of the LD light emitter to realize the conversion from an electric signal to a light signal; the arbitrary waveform generator is connected with the LDMOS series drive module, and the arbitrary waveform generator is used for generating waveforms; the visible light receiving end comprises a photoelectric detector, a trans-impedance amplifier, a voltage input type amplification device and a micro-control unit. The transimpedance amplifier is connected with the photoelectric detector, and the voltage input type amplification device is connected with the transimpedance amplifier; the micro-control unit is connected with the voltage input type amplification equipment; the photoelectric detector is used for receiving the visible light emitted by the LD light emitter and converting a modulated light signal into an electric signal; and the micro-control unit is used for decoding and restoring.

Description

An underwater visible light communication device and system with multiple transmitters and receivers Technical Field

[0001] This invention relates to the field of visible light communication (VLC) technology, and in particular to an underwater visible light communication device and system with multiple transmitters and multiple receivers. Background Technology

[0002] With the global commercialization of 5G, research institutions worldwide are shifting their focus to 6G. One goal of 6G is to achieve ubiquitous connectivity through the integration of satellite communication networks and underwater communication, providing global coverage. Underwater communication can be divided into wired underwater communication and wireless underwater communication. Wireless underwater communication refers to the transmission of data in the underwater environment via wireless carrier waves, which can be electromagnetic waves, sound waves, or light waves. Underwater wireless optical communication (UWOC), which uses light waves as the transmission medium, has advantages such as strong anti-interference capability, low power consumption, and small size compared to traditional underwater acoustic communication and underwater radio frequency communication, and has been widely studied in the field of underwater wireless communication. Various underwater visible light communication devices have also appeared on the market, but the following problems still exist:

[0003] 1. The underwater environment is complex, and communication equipment is subject to interference from water waves and ocean waves for a long time. Furthermore, the turbidity of seawater, suspended particles, scattering, and wave currents can affect the propagation of underwater light, which in turn makes it more difficult to connect the transmitter and receiver of visible light devices and affects the system's communication performance.

[0004] 2. The bit error rate is relatively high. Currently, optical communication equipment generally needs to be submerged at a depth of about 50m. Within this depth range, the light is extremely weak. Traditional systems cannot distinguish the effective light information sent by the transmitting module under strong light interference, resulting in an extremely high bit error rate.

[0005] In summary, there is an urgent need for an underwater visible light communication system with high anti-interference capabilities that can be applied in complex environments to achieve efficient underwater information transmission. Summary of the Invention

[0006] To address the bottlenecks in the existing technology, this invention provides an underwater visible light communication device and system with multiple transmitters and receivers. This improves the alignment accuracy and anti-interference capability of the transmitter and receiver in underwater visible light communication systems operating in complex environments.

[0007] The technical solution of this invention is as follows:

[0008] An underwater visible light communication device and system with multiple transmitters and receivers includes: an information input end, a visible light transmitter, a visible light receiver, and an information output end;

[0009] The visible light emitting terminal includes: a driving power supply, an LD light emitter, an LDMOS series driving module, and an arbitrary waveform generator. The driving power supply is connected to the LD light emitter and provides operating current to the LD light emitter. The LD light emitter emits blue-green laser light. The LDMOS series driving module is connected to the LD light emitter and modulates the signal onto the LD, converting the electrical signal into an optical signal by controlling the on / off state of the LD emitter, thus emitting the modulated visible light signal. The arbitrary waveform generator is connected to the LDMOS series driving circuit and generates waveforms. The optical receiver includes: a photodetector, a transimpedance amplifier, a voltage input amplifier, and a microcontroller unit; the transimpedance amplifier is connected to the photodetector, and the voltage input amplifier is connected to the transimpedance amplifier; the microcontroller unit is connected to the voltage input amplifier; the photodetector is disposed on the optical axis of the LED light emitter, and the photodetector is used to receive visible light emitted by the LED light emitter and convert the modulated optical signal into an electrical signal; the transimpedance amplifier is used to convert the current signal generated by the photodetector into a voltage signal; the voltage input amplifier is used to amplify the voltage signal, and the microcontroller unit is used for decoding and restoration.

[0010] The signal input device is connected to the arbitrary waveform generator in the visible light receiver, and the signal input device inputs a digital signal to the arbitrary waveform generator.

[0011] The signal output device is connected to the microcontroller unit in the visible light emitting end, and the signal output device is used to output the digital signal decoded and restored by the microcontroller unit.

[0012] In a further embodiment, the LD light emitter includes a laser light source, wherein the laser light source is a blue and green laser light source.

[0013] In a further embodiment, the LD light emitter includes multiple blue and green laser light sources connected in series.

[0014] In a further embodiment, the LD light emitter is equipped with an external optical lens, which includes a drive circuit board, a laser diode, a laser tube mounting base, a spring, a lens sleeve, a Powell lens, and a lens retaining ring. The drive circuit board is located at the bottom of the optical lens module; the laser diode is precisely mounted in the center of the laser tube mounting base; the spring is located between the laser diode and the lens sleeve at the front end of the optical system; the lens sleeve tightly surrounds and secures the Powell lens; the Powell lens is installed inside the lens sleeve; and the lens retaining ring firmly presses the Powell lens into the lens sleeve.

[0015] In a further embodiment, the photodetector is a PIN photodiode. A narrow-band optical filter is externally mounted on the PIN photodiode.

[0016] In a further embodiment, the photodetector includes a plurality of PIN photodiodes connected in series.

[0017] In a further embodiment, the voltage input amplification device includes a first-stage differential operational amplifier and a second-stage limiting amplifier connected together. The first-stage differential operational amplifier is connected to a transimpedance amplifier; the second-stage limiting amplifier is connected to the microcontroller unit; the microcontroller unit includes a comparator and a demodulator connected together.

[0018] In a further embodiment, the information input terminal is connected to the visible light emitting terminal, and the information output terminal is connected to the visible light receiving terminal. The information input terminal is used to input data information, and the information output terminal is used to output the received data information.

[0019] In a further embodiment, the present invention also provides an underwater visible light communication system, comprising: a bit error rate tester and an underwater visible light communication device as described in any one of the first aspects and possible embodiments thereof, wherein the bit error rate tester is connected to the visible light communication device.

[0020] The embodiments of the present invention bring the following beneficial effects:

[0021] This invention provides an underwater visible light communication device and system with multiple transmitters and receivers. The visible light communication device includes a visible light transmitter and a visible light receiver. The visible light transmitter includes a driving power supply, an LD light transmitter, an LDMOS series driving module, and an arbitrary waveform generator. The driving power supply is connected to the LD light transmitter and provides operating current to the LD light transmitter. The LD light transmitter emits blue-green laser light. The LDMOS series driving module is connected to the LD light transmitter and modulates the signal onto the LD. By controlling the on / off state of the LD light transmitter, the electrical signal is converted into an optical signal, emitting the modulated visible light signal. The arbitrary waveform generator is connected to the LDMOS series driving module. The OS series drive circuit is connected, and the arbitrary waveform generator is used to generate waveforms; the visible light receiver includes: a photodetector, a transimpedance amplifier, a voltage input amplification device, and a microcontroller unit; the transimpedance amplifier is connected to the photodetector, and the voltage input amplification device is connected to the transimpedance amplifier; the microcontroller unit is connected to the voltage input amplification device; the photodetector is disposed on the optical axis of the LED light emitter, and the photodetector is used to receive visible light emitted by the LD light emitter and convert the modulated light signal into an electrical signal; the transimpedance amplifier is used to convert the current signal generated by the photodetector into a voltage signal; the voltage input amplification device is used to amplify the voltage signal, and the microcontroller unit is used for decoding and restoration. In summary, the technical solution provided by the embodiments of the present invention alleviates the technical problem of low alignment between the transmitter and receiver of the visible light communication system in complex underwater environments, and can realize efficient information transmission underwater.

[0022] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained in accordance with the structures particularly pointed out in the description, claims and drawings.

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 is a schematic diagram of the basic structure of an underwater visible light communication device provided in an embodiment of the present invention;

[0026] Figure 2 is a detailed structural schematic diagram of an underwater visible light communication device provided in an embodiment of the present invention.

[0027] Figure 3 is a schematic diagram of the basic structure of another underwater visible light communication device provided in an embodiment of the present invention.

[0028] Figure 4 is a detailed structural schematic diagram of another underwater visible light communication device provided in an embodiment of the present invention.

[0029] Figure 5 is a schematic diagram of an underwater visible light communication system provided in an embodiment of the present invention. Detailed Implementation

[0030] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Currently, visible light communication has been extensively studied in the field of underwater wireless communication. Various underwater visible light communication devices have also appeared on the market, but problems such as the extreme difficulty in interfacing the transmitter and receiver of visible light devices and the extremely high system error rate still exist.

[0032] Based on this, the underwater visible light communication device and system with multiple transmitters and receivers provided in this embodiment of the invention can alleviate the technical problem of low alignment between the transmitter and receiver of the visible light communication system in complex underwater environments, and can realize efficient information transmission underwater.

[0033] To facilitate understanding of this embodiment, a detailed description of an optical communication device disclosed in this embodiment of the invention will be provided first.

[0034] Example 1:

[0035] As shown in Figures 1 and 2, an embodiment of the present invention provides an underwater visible light communication device, including: a visible light transmitter 1 and a visible light receiver 2.

[0036] The visible light emitting terminal 1 includes: a driving power supply 10, an LD light emitter 11, an LDMOS series driving module 12, and an arbitrary waveform generator 13. The driving power supply is connected to the LD light emitter and is used to provide operating current to the LD light emitter. The LD light emitter is used to emit blue-green laser light. The LDMOS series driving module is connected to the LD light emitter and is used to modulate the signal onto the LD. By controlling the on / off state of the LD light emitter, the electrical signal is converted into an optical signal, and the modulated visible light signal is emitted. The arbitrary waveform generator is connected to the LDMOS series driving circuit and is used to generate waveforms.

[0037] Furthermore, the drive power supply includes an AC-DC converter for converting AC power to DC power.

[0038] Furthermore, the LD light emitter includes a laser source, which employs both blue and green laser light sources. Compared to radio frequency signal-based wireless communication technology, the LD laser source can achieve a -3dB bandwidth of 100MHz with an input power of 10dBm, resulting in a significantly improved transmission speed.

[0039] Furthermore, the LDMOS series drive module is a single unit, connected in series with the LD light emitter. This ensures that the LD meets its high speed and high power requirements when lit.

[0040] Furthermore, the LDMOS series drive module modulates the signal onto the LD light emitter, and by controlling the on / off state of the LD light emitter, the electrical signal is converted into an optical signal, and the modulated visible light signal is emitted.

[0041] Furthermore, the LD light emitter includes multiple blue and green LD laser light sources connected in series. By forming an LD array through series connection, multiple light sources are emitted. The photodetector can achieve docking by receiving any one of the light sources, which greatly reduces the difficulty of alignment between the transmitter and receiver and ensures the reliability and integrity of signal transmission.

[0042] Furthermore, the LD light emitter is equipped with an external optical lens, which includes a drive circuit board, a laser diode, a laser tube mounting base, a spring, a lens sleeve, a Powell lens, and a lens retaining ring. The drive circuit board is located at the bottom or side of the optical lens module for easy connection to an external power supply and control system; the laser diode is precisely mounted in the center of the laser tube mounting base; the spring is located between the laser diode and the lens sleeve at the front end of the optical system, enabling fine adjustment of the laser diode's optical axis; the lens sleeve tightly surrounds and secures the Powell lens, ensuring its stable position during operation and preventing displacement due to vibration or temperature changes; the Powell lens is precisely mounted inside the lens sleeve, with its optical axis precisely aligned with the optical axis of the laser diode; the lens retaining ring is used to firmly press the Powell lens into the lens sleeve.

[0043] Furthermore, the arbitrary waveform generator employs an on-off keying (OOK) modulation method to reduce system complexity while meeting practical application requirements.

[0044] Specifically, in this embodiment, the LD light emitter includes three blue laser sources and two green laser sources, and the five laser sources are connected in series. The power MOSFETs in the LDMOS series drive module are N-type field-effect transistors; a microcontroller chip including an arbitrary waveform generator outputs a pseudo-random code sequence as the input signal for the visible light communication system.

[0045] The visible light receiver 2 includes: a photodetector 20, a transimpedance amplifier 21, a voltage input amplifier 22, and a microcontroller 23; the transimpedance amplifier is connected to the photodetector, and the voltage input amplifier is connected to the transimpedance amplifier; the microcontroller is connected to the voltage input amplifier; the photodetector is disposed on the optical axis of the LED light emitter, and the photodetector is used to receive visible light emitted by the LED light emitter and convert the modulated light signal into an electrical signal; the transimpedance amplifier is used to convert the current signal generated by the photodetector into a voltage signal; the voltage input amplifier is used to amplify the voltage signal, and the microcontroller is used for decoding and restoration.

[0046] Furthermore, the photoelectric sensor of the present invention uses a PIN photodiode. The PIN photodiode is chosen because this type of photodetector has a fast response speed, a high cutoff frequency, a low equivalent noise power parameter, and a low cost, making it a better choice for underwater visible light communication systems.

[0047] Furthermore, the photoelectric sensor includes four PIN photodiodes forming a 2*2 array, which enhances the receiver's reception of the optical signal emitted by the LD light transmitter over a longer transmission distance, greatly reducing the difficulty of aligning the transmitter and receiver and ensuring the reliability and integrity of signal transmission.

[0048] Furthermore, a narrow-band optical filter is mounted on the outside of the PIN photodiode to reduce the impact of signal crosstalk on communication, reduce the alignment requirements of the entire system, and thus increase the communication distance.

[0049] Furthermore, the voltage input amplification device includes a first-stage differential operational amplifier and a second-stage limiting amplifier connected together. The first-stage differential operational amplifier is connected to a transimpedance amplifier; the second-stage limiting amplifier is connected to the microcontroller unit; the microcontroller unit includes a comparator and a demodulator connected together. Specifically, the microcontroller unit is used to decode and restore the data information contained in the electrical signal.

[0050] Specifically, the input of the first-stage differential operational amplifier is connected to the transimpedance amplifier; the output of the first-stage differential operational amplifier is connected to the input of the second-stage limiting amplifier; and the output of the second-stage limiting amplifier is connected to the microcontroller unit.

[0051] Specifically, the transimpedance amplifier employs active inductor technology to improve frequency response. The first-stage differential amplifier amplifies the small-swing voltage signal output from the transimpedance amplifier, utilizing zero-pole cancellation technology to compress the gain in the low-frequency range and increase the gain in the high-frequency range, significantly expanding the receiver bandwidth. The second-stage limiting amplifier further amplifies the electrical signal to achieve the peak gain optimal for receiver bandwidth compensation. This maximizes the receiver's bandwidth while maintaining in-band flatness, improving data transmission rate and bit error rate performance.

[0052] Specifically, the first and second stage amplifiers include decoupling capacitor banks; these capacitor banks consist of resistors and capacitors, used to filter out high-frequency noise in the output signal. The output of the second-stage limiting amplifier is connected to the comparator of the microcontroller unit, and the comparator is connected to the demodulator. The first amplifier amplifies the electrical signal once, and the second amplifier, as the main amplifier, further amplifies the electrical signal (to 55dB). Finally, the comparator outputs an electrical pulse signal, which is then decoded and recovered by the demodulator.

[0053] Example 2:

[0054] As shown in Figures 3 and 4, this embodiment of the invention provides another optical communication device. The difference from the first embodiment is that the optical communication device further includes: an information input terminal 4 and an information output terminal 5; the information input terminal is connected to the visible light emitting terminal, and the information output terminal is connected to the visible light receiving terminal. The information input terminal is used to transmit data information, and the information output terminal is used to output the received data information.

[0055] Specifically, the information input terminal includes a personal computer. The information output terminal includes a mobile terminal.

[0056] Example 3:

[0057] As shown in Figure 5, this embodiment of the invention provides an optical communication system, including: a bit error rate tester 500 and an underwater visible light communication device 600 mentioned in the foregoing embodiment, wherein the bit error rate tester is connected to the underwater visible light communication device.

[0058] The bit error rate tester is used to test the bit error rate of the underwater visible light communication device.

[0059] The visible light communication system provided in this embodiment of the invention has the same technical features as the visible light communication device provided in the above embodiments, so it can also solve the same technical problems and achieve the same technical effects.

[0060] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A multi-transmitter, multi-receiver underwater visible light communication device, characterized in that... include: The system includes a visible light emitting end and a visible light receiving end. The visible light emitting end comprises: a driving power supply, an LD light emitter, an LDMOS series driving module, and an arbitrary waveform generator. The driving power supply is connected to the LD light emitter and provides operating current to the LD light emitter. The LD light emitter emits blue-green laser light. The LDMOS series driving module is connected to the LD light emitter and modulates the signal onto the LD, converting the electrical signal into an optical signal by controlling the on / off state of the LD emitter, thus emitting the modulated visible light signal. The arbitrary waveform generator is connected to the LDMOS series driving module and generates... Waveform; The visible light receiver includes: a photodetector, a transimpedance amplifier, a voltage input amplifier, and a microcontroller unit; the transimpedance amplifier is connected to the photodetector, and the voltage input amplifier is connected to the transimpedance amplifier; the microcontroller unit is connected to the voltage input amplifier; the photodetector is disposed on the optical axis of the LED light emitter, and the photodetector is used to receive visible light emitted by the LED light emitter and convert the modulated light signal into an electrical signal; the transimpedance amplifier is used to convert the current signal generated by the photodetector into a voltage signal; the voltage input amplifier is used to amplify the voltage signal, and the microcontroller unit is used for decoding and restoration.

2. The underwater visible light communication device according to claim 1, characterized in that, The LD light emitter includes a laser light source, which uses blue and green laser light sources.

3. The underwater visible light communication device according to claim 2, characterized in that, The LD light emitter includes multiple blue and green laser light sources connected in series.

4. The underwater visible light communication device according to claim 2, characterized in that, The LD light emitter is equipped with an external optical lens, which includes a drive circuit board, a laser diode, a laser tube fixing base, a spring, a lens sleeve, a Powell lens, and a lens retaining ring.

5. The underwater visible light communication device according to claim 1, characterized in that, The photodetector is a PIN photodiode. A bandpass narrow-band optical filter is mounted externally on the PIN photodiode.

6. The underwater visible light communication device according to claim 5, characterized in that, The photodetector includes multiple PIN photodiodes connected in series.

7. The underwater visible light communication device according to claim 1, characterized in that, The voltage input type amplification device includes a first-stage differential operational amplifier and a second-stage limiting amplifier connected together. The first-stage differential operational amplifier is connected to a transimpedance amplifier. The second-stage limiting amplifier is connected to the microcontroller unit. The microcontroller unit includes a comparator and a demodulator connected together.

8. The underwater visible light communication device according to claim 1, characterized in that, Also includes: The system includes an information input terminal and an information output terminal; the information input terminal is connected to the visible light emitting terminal, and the information output terminal is connected to the visible light receiving terminal; the information input terminal is used to input data information. The information output terminal is used to output the received data information.

9. A visible light communication system, characterized in that, include: The bit error rate tester and the visible light communication device as described in any one of claims 1-8, wherein the bit error rate tester is connected to the visible light communication device.

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