CN109150303B - An urban road laser communication method and system - Google Patents

Abstract

The invention provides an urban road laser communication method and system. The method includes: setting a laser communication pavement unit with a height similar to that of a street lamp in a specific area beside an urban road; at the same time, setting a laser communication vehicle-mounted unit at the top of the vehicle; When there is an area with a laser communication pavement unit, information exchange occurs between the laser communication pavement unit and the laser communication vehicle-mounted unit. The system includes: a laser communication pavement unit arranged on the side of an urban road and a laser communication vehicle-mounted unit arranged on the top of the vehicle and capable of information interaction with the laser communication pavement unit. When the vehicle travels near the laser communication pavement unit, the laser communication pavement unit in the present invention can aim to capture the position of the laser communication vehicle-mounted unit, and establish a stable communication link with it, and information exchange occurs, which is convenient for the laser communication pavement unit to obtain the driving vehicle. The real-time position and speed information is convenient for the laser communication vehicle-mounted unit to obtain road information.

Description

An urban road laser communication method and system

technical field

The invention belongs to the technical field of optical communication, relates to a laser communication method, and in particular relates to a laser communication transmission method and system suitable for medium and short distances in urban roads.

Background technique

As a new type of communication technology, optical wireless communication has the advantages of optical fiber communication and mobile communication at the same time. It can realize broadband transmission, flexible networking, no need for frequency application, anti-electromagnetic interference, and good confidentiality. research has received extensive attention. In addition, the light source for short- and medium-distance optical wireless communication also has the advantages of low power consumption, long life, low cost, and the like.

In an optical wireless communication system, the transmitting end uses an LED as the light source, and the receiving end uses a photodetector (PD) for receiving. However, the optical wireless communication system link passes through the atmospheric channel, which is greatly affected by the weather. At the same time, the optical wireless communication has the disadvantage of weak penetration and cannot penetrate non-transparent objects, so it is not as widely used as microwave communication.

The traditional acquisition, aiming and tracking method used in laser communication is mainly used in long-distance laser communication in space communication. Because it is mainly aimed at large-scale acquisition, aiming and tracking in space, optical antennas with high optical quality are mostly used, and coarse tracking servo turntables are constructed. Capture, Target, Track (ATP) system.

In order to provide an efficient and reliable laser communication channel, the following technologies are mainly used to improve the success probability, maintenance time and stability of the channel establishment: use a highly stable Position Sensitive Detector (PSD) to adjust the beam, use plasma The excimer eliminates the background light interference in the PSD to improve the accuracy of PSD detection. However, the current laser communication capture, aiming and tracking method is not miniaturized and portable, and cannot be widely used in ubiquitous network application scenarios such as the Internet of Vehicles.

SUMMARY OF THE INVENTION

In order to solve the above problems, the present invention provides a capturing, aiming and tracking method that can be used in urban road communication and urban road target positioning scenarios for laser communication and a system for implementing the method. It can make the vehicle conduct stable and efficient information exchange with the stationary information transceiver terminal on the roadside during the driving process.

In order to achieve the above object, the present invention provides the following technical solutions:

An urban road laser communication method, comprising the following steps:

A laser communication pavement unit with a height similar to that of a street lamp is installed in a specific area beside the urban road, and a laser communication vehicle-mounted unit is installed at the top of the vehicle;

When the vehicle passes through the area where the laser communication pavement unit is set, the information exchange occurs between the laser communication pavement unit and the laser communication vehicle-mounted unit:

The laser communication pavement unit receives the signal transmitted by the gateway, filters and amplifies the signal, and modulates the signal to light for transmission;

The laser communication vehicle unit receives the laser signal sent by the road unit, converts it into an electrical signal, performs filtering and amplification processing, demodulates the signal and moves it to the baseband, converts the signal into the corresponding QR code image, and transmits it to the roof of the car to display;

The laser communication pavement unit aims at the camera of the capture tracking module to obtain the QR code information, and extracts the information from the image.

Further, the information exchange step specifically includes the following processes:

The signal processing subsystem of the laser communication transmitting module in the laser communication pavement unit receives the signal transmitted by the gateway and transmits it to the digital signal receiving unit. The digital signal receiving unit filters and amplifies the signal and sends it to the optical modulation unit. The light modulation unit superimposes the received signal on the driving current signal of the laser LED to drive the LED light to emit light, thereby modulating the signal to the light for transmission;

The light detector in the receiving module of the laser communication vehicle unit receives the laser signal sent by the road unit, converts it into an electrical signal, transmits it to the receiving circuit for filtering and amplifying processing, and transmits it to the signal processing subsystem through the digital signal sending unit. The subsystem demodulates and moves the signal to the baseband, and then transmits the information to the control module and even the vehicle network through the digital signal line;

In the laser communication vehicle-mounted unit, the control module receives the digital signal transmitted by the vehicle-mounted network, and transmits it to the signal processing subsystem through the digital signal line. The signal processing subsystem converts the signal into the corresponding QR code image and transmits it to the roof display for processing Display; the camera of the laser communication pavement unit aiming, capturing and tracking module obtains the two-dimensional code information, and the signal processing subsystem receives the signal of the camera, extracts the information from the image, and then transmits the information to the control module through the digital signal line.

Further, the information exchange step also includes the following processes:

The laser communication road unit receives the position information and speed information of the laser communication vehicle-mounted unit transmitted through the QR code image, and uses the algorithm to realize the alignment and communication of the laser transmission module of the laser communication transmission module and the laser communication receiving module of the laser communication vehicle-mounted unit Link maintenance.

Further, the algorithm is a PID control algorithm.

An urban road laser communication system, comprising a laser communication pavement unit arranged on the side of an urban road and a laser communication vehicle-mounted unit arranged on the top of the vehicle and capable of information interaction with the laser communication pavement unit;

The laser communication road surface unit includes a laser communication transmitting module, an aiming, capturing and tracking module and a control module; wherein, the laser communication transmitting module includes a laser transmitting module and a signal processing subsystem, the laser transmitting module is connected with the signal processing subsystem, and the signal processing sub-system is connected. The system is connected to the back-end server of the pavement unit through a gateway; the laser transmitting module includes a digital signal receiving unit and an optical modulation unit, the digital signal receiving unit receives the digital signal sent from the signal processing subsystem, filters and amplifies it, and sends it to the optical modulation unit , the light modulation unit superimposes the received signal on the driving current signal of the laser LED, and drives the LED light to emit light, thereby modulating the signal to the light for transmission; the aiming, capturing and tracking module includes a camera module, a signal processing subsystem, a camera The module is connected to the signal processing subsystem and is used to transmit the collected image data to the signal processing subsystem; the signal processing subsystem receives the information from the digital signal line, modulates and moves the signal to the appropriate frequency band, and transmits the to the laser emission module; at the same time, it receives the signal from the camera, extracts the information from the image, and then transmits the information to the control module and even the gateway through the digital signal line; the control module is used to execute the aiming capture tracking algorithm and adjust the angle of the mechanical pan-tilt subsystem;

The laser communication vehicle-mounted unit includes at least one two-dimensional code display module, a laser communication receiving module and a control module, the two-dimensional code display module and the laser communication receiving module are respectively connected with the control module, and the control module is connected with the vehicle network; the two-dimensional code display module includes A display screen and a signal processing subsystem, the display screen is connected with the signal processing subsystem, and the signal processing subsystem is connected with the control module; the laser communication receiving module includes a photoelectric detection module and a signal processing subsystem, and the photoelectric detection module is connected with the signal processing subsystem The signal processing subsystem is connected to the control module; the photoelectric detection module includes a photodetector, a receiving circuit and a digital signal sending unit. The photodetector receives the laser signal sent by the road unit, converts it into an electrical signal, and transmits it to the receiving circuit for Filter and amplify, and transmit it to the signal processing subsystem through the digital signal sending unit; the signal processing subsystem of the laser communication vehicle-mounted unit receives the information from the control module through the digital signal line, and converts the signal into the corresponding two-dimensional code image , and transmit it to the display screen; at the same time, it also receives the signal from the laser communication receiving module, demodulates and moves it to the baseband, and then transmits the information to the control module and even the vehicle network through the digital signal line; the control module is used to coordinate the QR code display. Information transmission between the module and the vehicle network, and between the laser communication receiving module and the vehicle network.

Further, the display screen is arranged on the roof of the vehicle.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

1. In the scenario of unmanned driving, the present invention can realize the real-time information interaction between the traffic system of each road section and each vehicle, so as to control the traffic situation more effectively.

2. The present invention has a two-dimensional code information return mechanism, and uses visible light communication to transmit relevant information of the vehicle, thereby increasing the accuracy of aiming and tracking.

3. Compared with the traditional wireless communication, the method of the present invention can provide more efficient and accurate channel establishment, stronger data security and higher information transmission rate in the urban road scene.

4. The transmitter of the system can be coupled to the street light pole, which not only saves costs, but also facilitates large-scale applications.

5. Each part of the system is small in size, high in portability, low in complexity, and good in universality, which is conducive to promotion.

Description of drawings

Figure 1 is a schematic diagram of the structure of the laser communication pavement unit.

Figure 2 is a schematic diagram of the structure of the laser communication vehicle-mounted unit.

FIG. 3 is a schematic diagram of information interaction between the optical communication module and the laser communication vehicle-mounted unit.

Detailed ways

The technical solutions provided by the present invention will be described in detail below with reference to specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and not to limit the scope of the present invention.

The present invention provides an urban road laser communication method, comprising the following steps:

First, a laser communication pavement unit with a height similar to that of a street lamp is set up in a specific area beside an urban road, and a laser communication vehicle-mounted unit is set at the top of the vehicle.

When the vehicle passes through the area where the laser communication road surface unit is arranged, information exchange occurs between the laser communication road surface unit and the laser communication vehicle-mounted unit.

To realize the above method, the present invention provides an urban road laser communication system, including a laser communication pavement unit disposed on the side of the urban road and a laser communication vehicle-mounted unit disposed on the top of the vehicle capable of information interaction with the laser communication pavement unit.

As shown in Figure 1, the laser communication pavement unit is arranged around the road section, and the laser communication pavement unit is divided into three modules, namely the laser communication transmitting module, the aiming capture tracking module and the control module. The laser communication transmitting module includes a laser transmitting module and a signal processing subsystem, the laser transmitting module is connected with the signal processing subsystem, and the signal processing subsystem is connected with the back-end server of the road unit through a gateway. The laser transmitting module mainly includes a digital signal receiving unit and an optical modulation unit. The digital signal receiving unit receives the digital signal sent from the signal processing subsystem, performs filtering and amplification, etc., and sends it to the optical modulation unit, and the optical modulation unit will receive the digital signal. The signal of the laser is superimposed on the driving current signal of the laser LED to drive the LED light to emit light, thereby modulating the signal to the light for transmission. The aiming, capturing and tracking module includes a camera module, a mechanical pan-tilt sub-system, and a signal processing sub-system. The camera module is connected to the signal-processing sub-system and is used to transmit the collected image data to the signal-processing sub-system. The camera module is fixed on the mechanical pan-tilt sub-system. On the system, the angle of the camera module is adjusted by the mechanical pan-tilt subsystem. The mechanical pan-tilt subsystem is connected to the control module, and the control module controls the action of the mechanical pan-tilt subsystem. The control module is used to execute the aiming-acquisition tracking algorithm and adjust the angle of the mechanical pan-tilt subsystem. The control module includes a microcontroller, and adopts a control chip capable of receiving, calculating and processing signals, such as a single-chip microcomputer, a CPU, and the like. The signal processing subsystem receives the information from the digital signal line, modulates and moves the signal to the appropriate frequency band, and transmits it to the laser transmitter module; it also receives the signal from the camera, extracts information from the image, and then transmits the information through the digital The signal line is transmitted to the control module and even the gateway.

As shown in Figure 2, the laser communication vehicle-mounted unit includes at least one two-dimensional code display module, a laser communication receiving module and a control module. The two-dimensional code display module and the laser communication receiving module are respectively connected to the control module, and the control module is connected to the vehicle network. The two-dimensional code display module includes a large-area display screen and a signal processing subsystem, the large-area display screen is connected with the signal processing subsystem, and the signal processing subsystem is connected with the control module. The control module is used to coordinate the information transmission between the two-dimensional code display module and the vehicle network, and between the laser communication receiving module and the vehicle network. The control module includes a microcontroller, and adopts a control chip capable of receiving, calculating and processing signals, such as a single-chip microcomputer, a CPU, and the like. The laser communication receiving module includes a photoelectric detection module and a signal processing subsystem, the photoelectric detection module is connected with the signal processing subsystem, and the signal processing subsystem is connected with the control module. The photoelectric detection module includes a photodetector, a receiving circuit and a digital signal sending unit. The PD (photodetector) receives the laser signal from the road surface unit, converts it into an electrical signal, transmits it to the receiving circuit for filtering and amplifying processing, and transmits it to the signal processing subsystem through the digital signal sending unit. The signal processing subsystem of the laser communication vehicle unit receives the information from the control module through the digital signal line, converts the signal into the corresponding two-dimensional code image, and transmits it to the large-area display screen on the roof; at the same time, it also receives the information from the laser communication receiving module. The incoming signal is demodulated and moved to the baseband, and then the information is transmitted to the control module and even the in-vehicle network through the digital signal line. The laser communication vehicle-mounted unit is usually installed on the roof of the vehicle to facilitate signal transmission.

As shown in Figure 3, on the one hand, in the laser communication pavement unit, the signal processing subsystem of the laser communication transmitter module receives the signals transmitted by the gateway (including low-latency control information for automatic driving, vehicle multimedia information, road and weather information, etc.) , and transmitted to the digital signal receiving unit, the digital signal receiving unit filters and amplifies the signal, and sends it to the light modulation unit, which superimposes the received signal on the driving current signal of the laser LED to drive the LED light. emit light, thereby modulating a signal onto light for transmission. Then, the PD (photodetector) in the receiving module of the laser communication vehicle-mounted unit receives the laser signal sent by the road unit, converts it into an electrical signal, transmits it to the receiving circuit for filtering and amplifying processing, and transmits the signal to the signal through the digital signal sending unit processing subsystem. The above-mentioned signal processing subsystem demodulates and moves the signal to the baseband, and then transmits the information to the control module and even the in-vehicle network through the digital signal line. On the other hand, in the laser communication vehicle unit, the control module receives the digital signal (including speed and position information) transmitted by the vehicle network, and forwards it to the signal processing subsystem through the digital signal line. The signal processing subsystem converts the signal into a corresponding QR code image and transmits it to the large-area display screen on the roof for display. Next, the camera of the laser communication pavement unit's aiming, capturing and tracking module obtains the two-dimensional code information, and the signal processing subsystem receives the camera's signal, extracts the information (including position information and speed information) from the image, and then transmits the information through the digital signal line. to the control module and even the gateway.

The laser communication road unit receives the position information and speed information of the laser communication vehicle unit transmitted through the two-dimensional code image, and uses the algorithm (PID control algorithm) to realize the laser transmission module of the laser communication transmission module and the laser communication receiving module of the laser communication vehicle unit alignment and maintenance of the communication link.

Based on the above system and method, when the vehicle travels near the laser communication road unit, the laser communication road unit aims to capture the position of the laser communication vehicle-mounted unit, establishes a stable communication link with it, and exchanges information. It is convenient for the laser communication road unit to obtain the real-time position and speed information of the driving vehicle, and it is convenient for the laser communication vehicle-mounted unit to obtain road information, so as to overcome the fact that the current laser communication capture, aiming and tracking method is not miniaturized and portable, and cannot be used in ubiquitous network scenarios such as the Internet of Vehicles. commonly used insufficiency.

The technical means disclosed in the solution of the present invention are not limited to the technical means disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can also be made, and these improvements and modifications are also regarded as the protection scope of the present invention.

Claims (6)

1. The laser communication method for the urban road is characterized by comprising the following steps:

arranging a laser communication road surface unit with the height similar to that of a street lamp in a specific area beside an urban road, and arranging a laser communication vehicle-mounted unit at the top of a vehicle;

the laser communication pavement unit comprises a laser communication emission module, an aiming capturing tracking module and a control module; the system comprises a laser communication transmitting module, a signal processing subsystem and a road surface unit, wherein the laser communication transmitting module comprises a laser transmitting module and the signal processing subsystem; the laser emission module comprises a digital signal receiving unit and an optical modulation unit, wherein the digital signal receiving unit receives a digital signal sent from the signal processing subsystem, carries out filtering and amplification and sends the digital signal to the optical modulation unit, and the optical modulation unit superposes the received signal on a driving current signal of the laser LED to drive the LED lamp to emit light so as to modulate the signal to light for transmission; the aiming capture tracking module comprises a camera module and a signal processing subsystem, the camera module is connected with the signal processing subsystem and is used for transmitting acquired image data to the signal processing subsystem, the camera module is fixed on the mechanical cloud platform subsystem, the angle of the camera module is adjusted by the mechanical cloud platform subsystem, the mechanical cloud platform subsystem is connected with the control module, and the control module controls the action of the mechanical cloud platform subsystem; the control module is used for executing an aiming, capturing and tracking algorithm and adjusting the angle of the mechanical holder subsystem; the signal processing subsystem receives information transmitted from the digital signal wire, modulates and moves the signal to a proper frequency band, and transmits the signal to the laser emission module; meanwhile, receiving a signal from a camera, extracting information from an image, and transmitting the information to a control module or even a gateway through a digital signal line;

the laser communication vehicle-mounted unit comprises at least one two-dimensional code display module, a laser communication receiving module and a control module, wherein the two-dimensional code display module and the laser communication receiving module are respectively connected with the control module, and the control module is connected with a vehicle-mounted network; the two-dimensional code display module comprises a display screen and a signal processing subsystem, the display screen is connected with the signal processing subsystem, and the signal processing subsystem is connected with the control module; the laser communication receiving module comprises a photoelectric detection module and a signal processing subsystem, the photoelectric detection module is connected with the signal processing subsystem, and the signal processing subsystem is connected with the control module; the photoelectric detection module comprises a light detector, a receiving circuit and a digital signal sending unit, wherein the light detector receives laser signals sent by the pavement unit, converts the laser signals into electric signals, transmits the electric signals to the receiving circuit for filtering and amplifying, and transmits the electric signals to the signal processing subsystem through the digital signal sending unit; a signal processing subsystem of the laser communication vehicle-mounted unit receives information transmitted from the control module through a digital signal wire, converts the information into a corresponding two-dimensional code image and transmits the two-dimensional code image to a display screen; meanwhile, signals transmitted from the laser communication receiving module are received, demodulated and moved to a baseband, and then information is transmitted to the control module and even the vehicle-mounted network through the digital signal wire; the control module is used for coordinating information transmission between the two-dimensional code display module and the vehicle-mounted network and between the laser communication receiving module and the vehicle-mounted network;

when a vehicle passes through an area provided with the laser communication road surface unit, information interaction occurs between the laser communication road surface unit and the laser communication vehicle-mounted unit:

the laser communication pavement unit receives signals transmitted by the gateway, filters and amplifies the signals, and modulates the signals to light for transmission;

the laser communication vehicle-mounted unit receives a laser signal sent by the road surface unit, converts the laser signal into an electric signal, carries out filtering and amplification processing, demodulates and moves the signal to a baseband, converts the signal into a corresponding two-dimensional code image, and transmits the two-dimensional code image to the roof for display;

the laser communication pavement unit aims at a camera of the capturing and tracking module to acquire two-dimensional code information, and information is extracted from the image.

2. The urban road laser communication method according to claim 1, wherein said information interaction step specifically comprises the following steps:

a signal processing subsystem of a laser communication emitting module in a laser communication pavement unit receives a signal transmitted by a gateway and transmits the signal to a digital signal receiving unit, the digital signal receiving unit filters and amplifies the signal and transmits the signal to an optical modulation unit, and the optical modulation unit superposes the received signal on a driving current signal of a laser LED to drive an LED lamp to emit light, so that the signal is modulated to light to be transmitted;

the laser communication vehicle-mounted unit receiving module receives a laser signal sent by the road surface unit through the optical detector, converts the laser signal into an electric signal, transmits the electric signal to the receiving circuit for filtering and amplifying, transmits the electric signal to the signal processing subsystem through the digital signal sending unit, demodulates and moves the signal to a baseband through the signal processing subsystem, and then transmits the information to the control module and even a vehicle-mounted network through the digital signal wire;

in the laser communication vehicle-mounted unit, a control module receives a digital signal transmitted by a vehicle-mounted network, the digital signal is transmitted to a signal processing subsystem through a digital signal wire, and the signal processing subsystem converts the signal into a corresponding two-dimensional code image and transmits the two-dimensional code image to a vehicle roof display screen for display; the two-dimensional code information is acquired by a camera of the aiming capture tracking module of the laser communication pavement unit, and the signal processing subsystem receives signals of the camera, extracts information from images and then transmits the information to the control module through a digital signal line.

3. The urban road laser communication method according to claim 1, wherein the information interaction step further comprises the following processes:

the laser communication road surface unit receives the position information and the speed information of the laser communication vehicle-mounted unit transmitted by the two-dimensional code image, and the alignment of a laser transmitting module of the laser communication transmitting module and a laser communication receiving module of the laser communication vehicle-mounted unit and the maintenance of a communication link are realized by utilizing an algorithm.

4. The urban road laser communication method according to claim 1, wherein the algorithm is a PID control algorithm.

5. The laser communication system for the urban road is characterized by comprising a laser communication road surface unit arranged at the roadside of the urban road and a laser communication vehicle-mounted unit which is arranged at the top of a vehicle and can perform information interaction with the laser communication road surface unit;

the laser communication pavement unit comprises a laser communication emission module, an aiming acquisition tracking module and a control module; the system comprises a laser communication transmitting module, a signal processing subsystem and a data processing module, wherein the laser communication transmitting module comprises a laser transmitting module and the signal processing subsystem; the laser emission module comprises a digital signal receiving unit and an optical modulation unit, wherein the digital signal receiving unit receives a digital signal sent from the signal processing subsystem, carries out filtering and amplification and sends the digital signal to the optical modulation unit, and the optical modulation unit superposes the received signal on a driving current signal of the laser LED to drive the LED lamp to emit light so as to modulate the signal to light for transmission; the aiming capture tracking module comprises a camera module and a signal processing subsystem, the camera module is connected with the signal processing subsystem and is used for transmitting acquired image data to the signal processing subsystem, the camera module is fixed on the mechanical cloud platform subsystem, the angle of the camera module is adjusted by the mechanical cloud platform subsystem, the mechanical cloud platform subsystem is connected with the control module, and the control module controls the action of the mechanical cloud platform subsystem; the signal processing subsystem receives information transmitted from the digital signal wire, modulates and moves the signal to a proper frequency band, and transmits the signal to the laser emission module; meanwhile, receiving a signal from a camera, extracting information from an image, and transmitting the information to a control module or even a gateway through a digital signal line; the control module is used for executing an aiming, capturing and tracking algorithm and adjusting the angle of the mechanical holder subsystem;

the laser communication vehicle-mounted unit comprises at least one two-dimensional code display module, a laser communication receiving module and a control module, wherein the two-dimensional code display module and the laser communication receiving module are respectively connected with the control module, and the control module is connected with a vehicle-mounted network; the two-dimensional code display module comprises a display screen and a signal processing subsystem, the display screen is connected with the signal processing subsystem, and the signal processing subsystem is connected with the control module; the laser communication receiving module comprises a photoelectric detection module and a signal processing subsystem, the photoelectric detection module is connected with the signal processing subsystem, and the signal processing subsystem is connected with the control module; the photoelectric detection module comprises a light detector, a receiving circuit and a digital signal sending unit, wherein the light detector receives laser signals sent by the pavement unit, converts the laser signals into electric signals, transmits the electric signals to the receiving circuit for filtering and amplifying, and transmits the electric signals to the signal processing subsystem through the digital signal sending unit; a signal processing subsystem of the laser communication vehicle-mounted unit receives information transmitted from the control module through a digital signal wire, converts the information into a corresponding two-dimensional code image and transmits the two-dimensional code image to a display screen; meanwhile, signals transmitted from the laser communication receiving module are received, demodulated and moved to a baseband, and then information is transmitted to the control module and even the vehicle-mounted network through the digital signal wire; the control module is used for coordinating information transmission between the two-dimensional code display module and the vehicle-mounted network and between the laser communication receiving module and the vehicle-mounted network;

when a vehicle passes through an area provided with the laser communication road surface unit, information interaction occurs between the laser communication road surface unit and the laser communication vehicle-mounted unit:

the laser communication pavement unit receives signals transmitted by the gateway, filters and amplifies the signals, and modulates the signals to light for transmission;

the laser communication vehicle-mounted unit receives a laser signal sent by the road surface unit, converts the laser signal into an electric signal, performs filtering and amplification processing, demodulates and moves the signal to a baseband, converts the signal into a corresponding two-dimensional code image, and transmits the two-dimensional code image to the roof for display;

the laser communication pavement unit aims at a camera of the capturing and tracking module to acquire two-dimensional code information, and information is extracted from the image.

6. The urban road laser communication system according to claim 5, wherein the display screen is disposed on a vehicle roof.

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