Communication system based on visible light

Abstract

The invention provides a communication system based on visible light, each of a first visible light receiver and a second visible light receiver comprises a distance optimization receiving module, an angle optimization receiving module and a merging module, a receiving end of the distance optimization receiving module receives a first visible light signal irradiated at multiple angles, and a receiving end of the angle optimization receiving module receives a second visible light signal irradiated at multiple angles; a first electric signal is generated and sent to a first receiving end of the merging module through an output end; a receiving end of the angle optimization receiving module receives the first visible light signal, generates a second electric signal and sends the second electric signal to a second receiving end of the merging module through an output end; and the merging module merges the received first electric signal and the second electric signal, generates an optimized electric signal, and sends the optimized electric signal to a visible light receiving pin of the first control panel / the second control panel through an output end, so that the first control panel / the second control panel executes corresponding processing steps according to the optimized electric signal.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a visible light-based communication system. Background Art

[0002] Radio communication technology has become a vital infrastructure in the modern information society, widely used in mobile communications, the Internet of Things, broadcasting, and other fields. Traditional radio communications rely on electromagnetic waves to transmit information across space, but their application is constrained by transmission power limitations and electromagnetic interference. To address this issue, visible light communication (VLC) has emerged. This technology leverages the high-frequency flickering characteristics of LED lighting sources to transmit data, offering advantages such as zero electromagnetic radiation, unlicensed spectrum, and co-location with lighting equipment.

[0003] Existing visible light communication systems typically consist of LED lamps equipped with dedicated modulation circuits and terminal devices with photoelectric sensors, forming an integrated "lighting-communication" network architecture. In typical applications, downlink data is transmitted via the visible light band, while uplink data often uses infrared or radio frequency bands as a return channel. However, current systems have significant limitations: high-speed communication is only possible when the transmitter and receiver maintain a fixed relative orientation. If the terminal moves, obstructing the optical path or causing changes in the angle of incidence, the stability of the communication link decreases dramatically. Summary of the Invention

[0004] The purpose of the embodiments of the present application is to provide a visible light-based communication system to solve the technical problem of poor high-speed communication effect in existing visible light communication systems when the distance between the transmitter and the receiver is not fixed.

[0005] In the first aspect, the present invention provides a communication system based on visible light, which includes multiple communication terminals and multiple lamp ends. The communication terminals include a first visible light receiver, a first visible light transmitter and a first control board. The lamp ends include a second visible light receiver, a second visible light transmitter and a second control board. The first visible light receiver and the second visible light receiver both include a distance optimization receiving module, an angle optimization receiving module and a merging module. The receiving end of the distance optimization receiving module receives a first visible light signal illuminated at multiple angles, generates a first electrical signal and sends it to the first receiving end of the merging module through the output end; the receiving end of the angle optimization receiving module receives the first visible light signal, generates a second electrical signal and sends it to the second receiving end of the merging module through the output end; the merging module merges the received first electrical signal and the second electrical signal, generates an optimized electrical signal and sends it to the visible light receiving pin of the first control board / second control board through the output end, so that the first control board / second control board performs corresponding processing steps according to the optimized electrical signal.

[0006] In an optional embodiment, the distance optimization receiving module includes a convex lens and a first photodiode, wherein the convex lens is arranged at a first opening on the shell surface of the communication terminal and forms a first accommodating space with the shell, and the first photodiode is arranged in the first accommodating space and is located at the focus of the convex lens.

[0007] In an optional embodiment, the angle-optimized receiving module includes a plane light-transmitting mirror and a second photodiode, wherein the plane light-transmitting mirror is arranged at a second opening on the shell surface of the communication terminal and forms a second accommodation space with the shell, and the second photodiode is arranged in the second accommodation space and is located on the central axis of the plane light-transmitting mirror.

[0008] In an optional embodiment, the communication terminal further includes a voice receiver, the first control board includes a main control chip and a voice processing chip connected to each other, the voice receiver is connected to the voice processing chip, the first visible light emitter includes a third photodiode, and the third photodiode is connected to the main control chip. The voice receiver receives the voice of the holder of the communication terminal, generates an analog signal and sends it to the voice processing chip; The voice processing chip processes the received analog signal into a digital signal and sends it to the main control chip; The main control chip drives the third photodiode based on the received digital signal to emit a first visible light signal.

[0009] In an optional embodiment, the network ports of the second control boards of multiple lamp ends are connected via a network cable to form a local area network.

[0010] In an optional embodiment, after receiving the first visible light signal, the second visible light receiver at the target lamp end sends the optimized electrical signal to the second control board at the other lamp end via the local area network; The second control boards at other lamp ends each generate a corresponding second visible light signal according to the optimized electrical signal, and transmit it through the second visible light transmitter, so that the first visible light receiver of the communication terminal receives the second visible light signal at different positions.

[0011] In an optional embodiment, the communication terminal further includes a voice player, and the first visible light signal is used to indicate the audio data collected by the voice receiver, the terminal identifier and the channel identifier of the communication terminal. After receiving the optimized electrical signal corresponding to the first visible light signal, the main control chip received by the communication terminal determines whether the terminal identifier and channel identifier indicated by the first visible light signal have passed verification; If the verification is passed, the corresponding audio data will be played through the voice player.

[0012] In an optional embodiment, the communication terminal further includes a display, and the display is used to display the channel identification of the terminal device.

[0013] In an optional embodiment, the communication terminal further includes a communication button, The main control chip responds to the communication signal triggered by the communication button and controls the voice receiver to start collecting sound.

[0014] In an optional embodiment, after receiving the first visible light signal, the second visible light receiver of the target lamp end sends the optimized electrical signal to the second control boards of all other lamp ends under the current channel identifier through the local area network.

[0015] The present application provides a visible light-based communication system, wherein the communication system includes multiple communication terminals and multiple lamp ends, the communication terminal includes a first visible light receiver, a first visible light transmitter and a first control board, the lamp end includes a second visible light receiver, a second visible light transmitter and a second control board, the first visible light receiver and the second visible light receiver both include a distance optimization receiving module, an angle optimization receiving module and a merging module, the receiving end of the distance optimization receiving module receives a first visible light signal illuminated at multiple angles, generates a first electrical signal and sends it to the first receiving end of the merging module through the output end; the receiving end of the angle optimization receiving module receives the first visible light signal, generates a second electrical signal and sends it to the second receiving end of the merging module through the output end; the merging module merges the received first electrical signal and the second electrical signal, generates an optimized electrical signal and sends it to the visible light receiving pin of the first control board / second control board through the output end, so that the first control board / second control board performs corresponding processing steps according to the optimized electrical signal. By adding optical devices to the visible light receiver, the visible light receiver can receive light at a wider angle and longer distance, thereby alleviating the angle and distance limitations of the visible light communication network. Good high-speed communication can be achieved even when the transmitting and receiving ends are moving relative to each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 A schematic diagram of the structure of a visible light communication system provided in an embodiment of the present application; Figure 2 A schematic diagram of a logic control structure of a communication terminal provided in an embodiment of the present application; Figure 3 A schematic diagram of the logic control structure of a lamp end provided in an embodiment of the present application. DETAILED DESCRIPTION

[0018] First, the application scenario of this application is described. The technical solution of this application can be applied to visible light communication.

[0019] Existing visible light communication systems transmit downlink data via visible light bands, while uplink data often uses infrared or radio frequency bands as return channels, forming an integrated "lighting-communication" network architecture. However, traditional visible light communication systems suffer from poor mobile reception, limited coverage, and are unsuitable for use in certain scenarios where infrared signals are restricted.

[0020] Based on this, the present application provides a visible light based communication system.

[0021] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0022] Example 1 Figure 1 This is a schematic diagram of the structure of a visible light communication system provided in an embodiment of the present application. Figure 1 As shown, the communication system includes multiple communication terminals and multiple lamp terminals. The specific number of communication terminals and lamp terminals is not limited here.

[0023] The communication terminal includes a first visible light receiver, a first visible light transmitter and a first control board. The first visible light transmitter may be an LED lamp.

[0024] The lamp end includes a second visible light receiver, a second visible light emitter and a second control board. The second visible light emitter can be an LED lamp.

[0025] In visible light communication systems, LED lights also have to provide illumination for engineering reasons, so their light is typically dispersed. Based on the characteristics of light, the more concentrated the light, the higher the energy, the more communication data can be transmitted, and the higher the transmission rate, but the transmission distance will be shorter.

[0026] In this embodiment, the visible light transmitter has the function of lighting and performs optical modulation on all downlink data. While the LED lamp performs light dispersion processing, the present application also performs large-angle and long-distance light convergence and collection on the visible light receiver.

[0027] The first visible light receiver and the second visible light receiver each include a distance optimization receiving module, an angle optimization receiving module and a merging module.

[0028] The distance optimization receiving module herein may include a convex lens and a first photodiode, wherein the convex lens is disposed at a first opening on the surface of a housing of the communication terminal and forms a first accommodation space with the housing, and the first photodiode is disposed within the first accommodation space and at the focal point of the convex lens. The receiving end of the distance optimization receiving module receives the first visible light signal illuminated from multiple angles, generates a first electrical signal, and transmits it to the first receiving end of the merging module via the output end.

[0029] Specifically, the convex lens can be mounted on an opening on the surface of the front housing of the communication terminal / lamp end through a fixing seat. The front housing and the rear housing are fixed by buckles.

[0030] The angle-optimized receiving module includes a flat mirror and a second photodiode. The flat mirror is positioned at a second opening on the surface of the communication terminal's housing and forms a second storage space with the housing. The second photodiode is positioned within the second storage space and is located on the central axis of the flat mirror. The second photodiode can receive incident light with an angle of incidence of 30° to 150° through the flat mirror. The receiving end of the angle-optimized receiving module receives the first visible light signal and generates a second electrical signal, which is transmitted through the output end to the second receiving end of the merging module.

[0031] The plane light-transmitting mirror can be glued to the opening of the front housing surface of the communication terminal / lamp end. The plane light-transmitting mirror can be made of a transparent acrylic sheet, transparent glass or other transparent materials.

[0032] Specifically, when an external light source shines perpendicularly on the convex lens, the light is focused onto the first photodiode. Under the same light intensity, the convex lens focuses the light, increasing the diode's current. This allows the receiver with the convex lens to still receive long-distance signals even when the distance between the light source and the receiver increases. The angle-optimized receiving module can also receive light at larger angles, enabling wide-angle signal reception.

[0033] When a visible light source strikes a photodiode at a non-perpendicular angle (at an angle), the convex lens above the first photodiode has a narrow focusing angle, resulting in a weak signal on the first photodiode. At this point, the second photodiode, acting as a flat mirror, receives the light signal at a specific angle.

[0034] The merging module merges the received first electrical signal and the second electrical signal to generate an optimized electrical signal, which is sent to the visible light receiving pin of the first control board / second control board through the output end, so that the first control board / second control board performs corresponding processing steps according to the optimized electrical signal.

[0035] The combining module combines the first and second electrical signals. Specifically, it can employ a variety of signal combining algorithms, including Maximum Ratio Combining (MRC), Equal Gain Combining (EGC), Selective Combining (SC), and Switching Combining, though these are not specifically defined. The optimized electrical signal output by the combining module combines the first electrical signal from the distance-optimized receiving module and the second electrical signal from the angle-optimized receiving module, significantly reducing the probability of signal fading and ensuring communication quality.

[0036] The present application provides a visible light-based communication system, which adds optical devices to the visible light receiver so that the visible light receiver can receive light at a larger angle and longer distance, thereby alleviating the angle and distance limitations of the visible light communication network, and can achieve good high-speed communication even when the transmitting and receiving ends are moving relative to each other.

[0037] Example 2 In one embodiment of the present application, a communication method of a visible light-based communication system is provided.

[0038] The network ports of the second control boards of multiple lamp terminals are connected via network cables to form a local area network, so that signals can be exchanged between different lamp terminals.

[0039] The communication terminal here also includes a voice receiver and a voice player. The first control board includes a main control chip and a voice processing chip connected to each other. The voice receiver is connected to the voice processing chip. The first visible light emitter includes a third photodiode, and the third photodiode is connected to the main control chip.

[0040] The chip here may be an MCU (Microcontroller Unit) or the like.

[0041] The voice receiver can be a microphone for collecting the user's voice. The voice receiver receives the user's voice from the communication terminal, generates an analog signal, and transmits it to the voice processing chip. The voice processing chip processes the received analog signal into a digital signal and transmits it to the main control chip. Based on the received digital signal, the main control chip drives the third photodiode to emit a first visible light signal. The voice player can be an amplifier and a speaker. The communication terminal may also include a headphone jack for the user to use headphones.

[0042] After receiving the first visible light signal, the second visible light receiver at the target lamp sends an optimized electrical signal via the local area network to the second control boards at the other lamps. The second control boards at the other lamps each generate corresponding second visible light signals based on the optimized electrical signal and transmit them via their second visible light transmitters, allowing the first visible light receiver at the communication terminal to receive the second visible light signals. The communication terminal can then convert the received first visible light signal into corresponding audio data and play it back.

[0043] For example, communication terminal A can convert the user's voice into a corresponding visible light signal and send it to lamp terminal A. Light terminal A can receive the first visible light signal through a second visible light receiver and forward it to lamp terminal B via a network cable. Lamp terminal B, based on the optimized electrical signal, converts it into a corresponding second visible light signal through a second control board and sends it to communication terminal B through a second visible light transmitter. Communication terminal B receives the signal through the first visible light receiver and plays it through a voice player.

[0044] In one embodiment, to avoid communication channel congestion, each communication terminal may be preset with a corresponding communication terminal ID. The second control board of the lamp end may store all communication terminal IDs, and the lamp end establishes a data transmission channel by identifying the communication terminal ID.

[0045] The first visible light signal emitted by the communication terminal or the lamp end is used to indicate the audio data collected by the voice receiver and can also indicate the terminal identifier and channel identifier of the corresponding communication terminal.

[0046] The light terminal identifies the terminal identifier and channel identifier indicated by the first visible light signal sent by the communication terminal. For different channel identifiers, frequency division multiplexing can be implemented using hybrid multiplexing technology, with different channels using different sub-bands. This can include spatial multiplexing (SDM) and frequency division multiplexing (FDM), such as MIMO-OFDM, which implements spatial multiplexing through multiple transmit and receive arrays in the system.

[0047] Exemplarily, after receiving the optimized electrical signal corresponding to the first visible light signal, the main control chip of the communication terminal determines whether the terminal identifier and channel identifier indicated by the first visible light signal have passed verification. If so, the corresponding audio data is played through the voice player.

[0048] In this way, the lamp end can be connected to multiple communication terminals to avoid communication confusion between different communication terminals.

[0049] Example 3 In this embodiment, a communication terminal and a lamp terminal are provided.

[0050] The logic control structure principle diagram of the communication terminal can be as follows: Figure 2As shown. The communication terminal may be a handheld terminal. The communication terminal may include a first visible light receiver, a first visible light transmitter, and a first control board. The first control board may include a main control chip, a voice processing chip, a charging management chip, an EEPROM chip, a FLASH chip, and a fuel meter chip that are interconnected.

[0051] The communication terminal also includes a display, which is used to display the channel identification of the terminal device, the terminal name, etc. It can also display information such as the working status, power, volume, etc. of the communication terminal.

[0052] The main control chip of the communication terminal is connected to an indicator light via a GPIO pin. The indicator light can indicate the working status of the communication terminal, the battery / charging status, and the voice upload / answer prompt. The indicator light here can be a red and green dual-color LED light.

[0053] In an optional embodiment, the communication terminal further includes a communication button, and the main control chip is connected to the button via a GPIO pin. In response to the communication signal triggered by the communication button, the main control chip controls the voice receiver to begin collecting sound. The button may be multiple buttons, each used for controlling "volume up," "volume down," "PTT," "channel switching," and "power on / off." Power on / off control, volume up / down control, and channel switching control are unaffected by the service and can be adjusted by the user at any time. The effectiveness of the PTT control button is affected by the service and only controls voice services after successfully acquiring channel resources.

[0054] The main control chip of the communication terminal also has a Type-C interface connected to the SWD / USART pin. The Type-C interface can be used for battery charging, program burning, communication, etc., and can also be used as a headphone interface.

[0055] The main control chip of the communication terminal is also connected to the battery voltage acquisition circuit through the ADC pin to monitor the battery status.

[0056] The main control chip of the communication terminal is also connected to the fuel meter chip through the IIC / GPIO pin, connected to the charging management chip through the GPIO pin, connected to the Flash chip through the SPI pin, and connected to the EEPROM chip through the IIC pin.

[0057] A detector operational amplifier and a comparator circuit are also connected between the main control chip of the communication terminal and the output end of the merging module. The main control chip of the communication terminal is connected to the detector operational amplifier and the comparator circuit through a USART pin.

[0058] The communication terminal's main control chip is connected to the voice processing chip via IIC / SPI pins. The voice processing chip is responsible for signal encoding and decoding. The analog signal collected by the microphone is converted into a digital signal, which is then encoded and modulated by the voice processing chip and sent to the main control chip. The main control chip drives the corresponding LED based on the received modulated signal, converting the sound signal into a light signal.

[0059] In a specific embodiment, the communication terminal can actively connect to the lamp terminal. If the communication terminal does not receive a heartbeat packet from the lamp within a certain timeout period, it will automatically go offline. When the communication terminal is placed under the lamp, it will automatically start connecting. This function ensures that the communication terminal is controlled by the system after joining the network, ensuring the orderly and secure optical path interaction when multiple users are concurrently under the lamp.

[0060] After a communication terminal has been idle for 2 minutes, it automatically turns off the screen and other peripherals and enters sleep mode. While in sleep mode, the terminal still maintains the ability to monitor services and automatically exits sleep mode when it detects any event, such as a status change or the presence of services.

[0061] After successfully joining the network, the communication terminal can provide voice services to users. When the communication terminal recognizes the user pressing the PTT button, it requests channel resources from the light terminal, collects the sound through the microphone, compresses it, and transmits it to the light terminal via the optical path. The display simultaneously prompts the user to complete the voice upload. When the communication terminal monitors the optical signal sent by the light terminal, it automatically analyzes the optical signal. If the terminal and channel identifiers are correct, it decodes and plays the signal, and can also provide a prompt on the display.

[0062] Among them, the logic control structure schematic diagram of the lamp end can be as follows Figure 3 The lamp end is equipped with a TYPE-C interface, a DC interface, an LED light control interface, a visible light receiving port, an Ethernet interface, and an indicator light control interface.

[0063] The TYPE-C port can be connected to the main control chip on the lamp side via SWD or USART pins for program programming and communication. The DC (power) port outputs switching signals to the LED driver board. The visible light receiving port receives optimized electrical signals. The Ethernet port allows for bidirectional data transmission with other lamps. The LED light control port can be connected to the main control chip on the lamp side via USART pins to control the visible light signals emitted by the LEDs. The indicator light control port can be connected to the main control chip on the lamp side via GPIO pins to control the indicator lights. The indicator lights indicate the operating status of the lamp side.

[0064] The second visible light receiver, second visible light emitter, and second control board at the lamp end can be integrated into the same housing or formed separately. For example, the second control board and second visible light emitter body can be deployed on the ceiling, and the second visible light receiver body can be deployed on the ceiling or wall.

[0065] After the communication system is initialized and the communication terminal is successfully connected to the lamp end, the lamp end can record the terminal identifier and channel identifier of the communication terminal and start periodic polling of the terminal. If the terminal does not respond after the timeout, it is considered offline and all resources occupied by the device are released.

[0066] The light terminal can automatically monitor the voice packets reported by the terminal and transmit the optimized electrical signals corresponding to the voice data reported by the communication terminal in the form of network packets to other light terminals in the local area network. The light terminal also automatically monitors the network packets in the local area network and sends the network packets to the communication terminal in the form of optical signals.

[0067] When the light end receives the network access / offline or voice application from the communication terminal, it can also determine whether the channel resources meet the requirements and send a response to the communication terminal based on the judgment result.

[0068] In the embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interface, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0069] In addition, the units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0070] Furthermore, the functional modules in each embodiment of the present application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0071] It should be noted that if the function is implemented in the form of a software function module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the existing technology, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, and other media that can store program code.

[0072] In this document, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any actual relationship or order between these entities or operations.

[0073] The above description is merely an embodiment of the present application and is not intended to limit the scope of protection of the present application. For those skilled in the art, various modifications and variations of the present application are possible. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A visible light based communication system, characterized in that: The communication system includes multiple communication terminals and multiple lamp ends, wherein the communication terminal includes a first visible light receiver, a first visible light transmitter and a first control board, and the lamp end includes a second visible light receiver, a second visible light transmitter and a second control board. The first visible light receiver and the second visible light receiver each include a distance optimization receiving module, an angle optimization receiving module and a merging module. The receiving end of the distance optimization receiving module receives the first visible light signal illuminated from multiple angles, generates a first electrical signal, and sends the first electrical signal to the first receiving end of the merging module through the output end; The receiving end of the angle optimization receiving module receives the first visible light signal, generates a second electrical signal, and sends the second electrical signal to the second receiving end of the merging module through the output end; The merging module merges the received first electrical signal and the second electrical signal to generate an optimized electrical signal, which is sent to the visible light receiving pin of the first control board / second control board through the output end, so that the first control board / second control board performs corresponding processing steps according to the optimized electrical signal.

2. The system according to claim 1, wherein: The distance optimization receiving module includes a convex lens and a first photodiode, wherein the convex lens is arranged at a first opening on the shell surface of the communication terminal and forms a first accommodating space with the shell, and the first photodiode is arranged in the first accommodating space and is located at the focus of the convex lens.

3. The system according to claim 1, wherein: The angle-optimized receiving module includes a plane light-transmitting mirror and a second photodiode, wherein the plane light-transmitting mirror is arranged at a second opening on the shell surface of the communication terminal and forms a second accommodation space with the shell, and the second photodiode is arranged in the second accommodation space and is located on the central axis of the plane light-transmitting mirror.

4. The system according to claim 1, wherein: The communication terminal further includes a voice receiver, the first control board includes a main control chip and a voice processing chip connected to each other, the voice receiver is connected to the voice processing chip, the first visible light emitter includes a third photodiode, and the third photodiode is connected to the main control chip. The voice receiver receives the voice of the holder of the communication terminal, generates an analog signal and sends it to the voice processing chip; The voice processing chip processes the received analog signal into a digital signal and sends it to the main control chip; The main control chip drives the third photodiode based on the received digital signal to emit a first visible light signal.

5. The system according to claim 4, characterized in that The network ports of the second control boards of the multiple lamp terminals are connected via network cables to form a local area network.

6. The system according to claim 5, characterized in that After receiving the first visible light signal, the second visible light receiver at the target lamp end sends the optimized electrical signal to the second control board at the other lamp end through the local area network; The second control boards at other lamp ends each generate a corresponding second visible light signal according to the optimized electrical signal, and transmit it through the second visible light transmitter, so that the first visible light receiver of the communication terminal receives the second visible light signal at different positions.

7. The system according to claim 6, characterized in that The communication terminal also includes a voice player, and the first visible light signal is used to indicate the audio data collected by the voice receiver, the terminal identifier and the channel identifier of the communication terminal, After receiving the optimized electrical signal corresponding to the first visible light signal, the main control chip received by the communication terminal determines whether the terminal identifier and channel identifier indicated by the first visible light signal have passed verification; If the verification is passed, the corresponding audio data will be played through the voice player.

8. The system according to claim 4, wherein: The communication terminal further includes a display, which is used to display the channel identification of the terminal device.

9. The system according to claim 4, wherein: The communication terminal also includes a communication button, The main control chip responds to the communication signal triggered by the communication button and controls the voice receiver to start collecting sound.

10. The system according to claim 7, wherein: After receiving the first visible light signal, the second visible light receiver of the target lamp end sends the optimized electrical signal to the second control boards of all other lamp ends under the current channel identifier through the local area network.

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