A data communication system and method using optical transmission in free space

Abstract

The present invention discloses a data communication system for optical transmission in free space, including a transmitting subsystem and a receiving subsystem; the transmitting subsystem includes a transmitting system component and a transmitting system optical servo platform; the transmitting system component can realize operation in different bands by replacing components; the transmitting system optical servo platform is used to control and stabilize the transmission of optical signals; the receiving subsystem includes a receiving system component and a receiving system optical servo platform; through the design of the present invention, the system can be used for both optical transmission data communication and free space optical communication test analysis. Among them, the transmitting subsystem is responsible for generating and sending optical signals, and the receiving subsystem is responsible for receiving, processing and analyzing optical signals. The optical servo platform is used to stabilize and control the transmission of optical signals.

Description

Technical Field

[0001] The present invention belongs to the technical field of signal communication, and in particular relates to a data communication system utilizing optical transmission in free space. Background Art

[0002] Free space laser communication technology combines the advantages of radio communication and optical fiber communication, using laser as carrier for communication. Compared with the bandwidth limitation, electromagnetic interference, easy eavesdropping and interception risks brought by traditional communication, free space optical communication has the advantages of higher bandwidth, better anti-interference, higher security, longer transmission distance and lower deployment cost.

[0003] The existing free-space laser communication technology mainly consists of a laser transmitter, an optical lens, and an optical transceiver. Among them, the laser transmitter is a device used to generate a laser beam, usually a semiconductor laser or a solid-state laser. The optical lens is used to adjust and focus the laser beam to ensure the transmission quality and stability of the beam. The optical transceiver is used to receive and decode the transmitted laser signal and convert it into an electrical signal for processing. However, the existing free-space laser communication technology devices are difficult to adjust and require high precision, so there is a problem of high layout costs.

[0004] The patent with publication number CN103748812A discloses an integrated commercial communication network using radio frequency and free space optical data communication; it combines an E-band (71-76GHz, 81-86GHz) millimeter wave RF transceiver with an eye-safe adaptive optical device free space optical (FSO) transceiver into a combined device for simultaneous point-to-point commercial communication. However, the device has high structural requirements, so there is a problem of high installation cost. Summary of the invention

[0005] The object of the present invention is to provide a data communication system using optical transmission in free space to solve the following technical problems raised in the background technology:

[0006] The existing free-space laser communication technology has the problem of high deployment costs because the devices are difficult to adjust and require very high precision.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0008] A data communication system utilizing optical transmission in free space, comprising a transmitting terminal system and a receiving terminal system;

[0009] The transmitting subsystem includes a transmitting system component and a transmitting system optical servo platform; the components in the transmitting system component work together to generate and send optical signals; the transmitting system component can achieve operation in different bands by replacing components; the transmitting system optical servo platform is used to control and stabilize the transmission of optical signals;

[0010] The receiving subsystem includes a receiving system component and a receiving system optical servo platform; the receiving system component is used to receive, process and analyze the optical signal transmitted by the transmitting system optical servo platform, and the receiving system optical servo platform is used to stabilize and control the received optical signal.

[0011] Furthermore, the transmitting system components include a GNSS disciplined clock, a vector signal source, a balun, an RF driver amplifier, an IQ electro-optic modulator, a laser source, a bias power supply controller, an intensity electro-optic modulator, a DC controller, an optical fiber power amplifier and a transmitting chassis component; wherein the IQ electro-optic modulator and the intensity electro-optic modulator are interchangeable components; the transmitting chassis component includes a first chassis, an industrial computer, a display, a mouse, a keyboard, a first chassis power supply and a first chassis fan.

[0012] Furthermore, the optical servo platform of the launch system includes a fiber power amplifier, a first polarization controller, a second polarization controller, a first collimator, a second collimator and a launch platform assembly; wherein the first polarization controller and the first collimator correspond to the IQ electro-optic modulator; the second polarization controller and the second collimator correspond to the intensity electro-optic modulator.

[0013] Furthermore, the launch platform assembly includes a first turntable and a first tripod, wherein the first turntable is used to control the position of the launch end, and the first tripod is used to support the optical servo platform of the launch system.

[0014] Furthermore, the receiving system components include an optoelectronic converter, a down converter, an oscilloscope, a GNSS disciplined clock, a filter and a receiving chassis component, and the receiving chassis component includes a second chassis, a second chassis power supply and a second chassis fan.

[0015] Furthermore, the optical servo platform of the receiving system includes a first coupling mirror, a second coupling mirror, an optical fiber low noise amplifier and a receiving platform component.

[0016] Furthermore, the receiving platform assembly includes a second turntable and a second tripod, wherein the second turntable is used to control the position of the receiving end, and the second tripod is used to support the optical servo platform of the receiving system.

[0017] Furthermore, the data communication system also includes auxiliary testing tools, which include a frequency multiplication card, an optical power meter, and laser protective glasses; the auxiliary testing tools are used to verify equipment indicators and perform system performance testing.

[0018] A data communication method using optical transmission in free space, a data communication system using optical transmission in free space, including a signal sending method and a signal receiving method;

[0019] The specific steps of the signal sending method are as follows:

[0020] A1, using GNSS to tame the clock signal of the clock synchronization system;

[0021] A2, using a vector signal source to generate a high-frequency signal as a modulation source for the optical signal;

[0022] A3, using a balun to convert the differential IQ baseband signal into a single-ended IQ signal, and amplifying it through an RF driver amplifier; or using an RF driver amplifier to amplify the input signal to a high enough level to drive the RF output load, and modulating the signal through an intensity modulator;

[0023] A4, using a laser source to provide an initial light source;

[0024] A5, using an IQ electro-optical modulator or an intensity electro-optical modulator to convert the electrical signal into an optical signal and modulate it for transmission;

[0025] A6, using the bias power supply controller to provide stable voltage and current for the IQ electro-optic modulator; using the DC controller to control the output of the DC power supply to ensure the normal operation of the intensity electro-optic modulator;

[0026] A7, uses fiber optic amplifier to amplify optical signals, enhancing transmission distance and signal quality;

[0027] The signal receiving method is as follows:

[0028] S1, after the optical signal is received, it is converted into an electrical signal through a photoelectric converter;

[0029] S2, using a down converter to reduce the frequency of the high frequency signal;

[0030] S3, using an oscilloscope to observe and analyze the signal waveform;

[0031] S4, using the GNSS disciplined clock to synchronize the clock signal of the receiving system;

[0032] S5, uses optical fiber low noise amplifier to amplify optical signals and enhance the quality of received signals;

[0033] S6, the filter filters out unnecessary signal components and improves the purity of the signal.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] The transmitter terminal system of the present invention can realize the operation of 1550nm and 1064nm bands by replacing components, thereby supporting the optical transmission requirements of different bands. This makes the system more flexible and applicable. At the same time, the design of this module makes the replacement and maintenance of components more convenient and economical, and can also achieve the versatility of components, reducing the number and cost of components in specific bands.

[0036] In the present invention, based on the design of 1550nm vector modem, complex signals with real and imaginary parts can be measured and analyzed, providing greater measurement flexibility and more data results and trace displays. This provides more options and optimizations for modulation format and demodulation algorithm configuration.

[0037] In the present invention, by adding a 1064nm intensity modulator, the system can perform intensity modulation and demodulation processing, and the wavelength coverage range is 980~1150nm, which provides a wider range of applications and flexibility.

[0038] The entire system of the present invention can also be used for testing and analyzing free-space optical communication links, including modulation and demodulation processing of vector signals, so as to obtain more complete free-space optical communication test data and evaluate and optimize system performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic diagram of the structure of the transmitter terminal system using a 1550nm IQ electro-optical modulator;

[0040] Figure 2 This is a schematic diagram of the receiving terminal system structure using a 1550nm IQ electro-optical modulator;

[0041] Figure 3 This is a schematic diagram of the structure of the transmitting terminal system using a 1064nm intensity electro-optic modulator;

[0042] Figure 4 Schematic diagram of the receiving terminal system structure using a 1064nm intensity electro-optic modulator. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example

[0044] A data communication system using optical transmission in free space. At the same time, the present application is also a free space optical communication test system using fiber coupling technology; including a transmitting terminal system and a receiving terminal system;

[0045] The transmitting subsystem includes a transmitting system component and a transmitting system optical servo platform; the components in the transmitting system component work together to generate and send optical signals; the transmitting system component can achieve work in different bands by replacing components; Figures 1 to 4 As shown, it can support 1550nm and 1064nm bands; Figure 1 to Figure 2 As shown in the figure, the 1550nm vector modem can be used to measure and analyze vector modulation signals. Vector modulation analysis refers to the measurement and analysis of complex signals with real and imaginary parts. It provides greater measurement flexibility in modulation format and demodulation algorithm configuration, and provides more data results and trace displays. Figure 3 to Figure 4 As shown in the figure, based on the 1064nm intensity modulation and demodulation free space optical communication test system, the system adds an intensity modulator, and the wavelength covers 980~1150nm. The entire system can realize the actual test analysis of the free space optical communication link and the modulation and demodulation processing of the vector signal, and can obtain more complete free space optical communication test data. The optical servo platform of the transmission system is used to control and stabilize the transmission of optical signals.

[0046] The receiving subsystem includes a receiving system component and a receiving system optical servo platform; the receiving system component is used to receive, process and analyze the optical signal transmitted by the transmitting system optical servo platform, and the receiving system optical servo platform is used to stabilize and control the received optical signal.

[0047] Through the design of the present invention, the system can be used for both optical transmission data communication and free space optical communication test analysis. The transmitting subsystem is responsible for generating and sending optical signals, and the receiving subsystem is responsible for receiving, processing and analyzing optical signals. The optical servo platform is used to stabilize and control the transmission of optical signals.

[0048] In a preferred embodiment, the transmitting system components include a GNSS disciplined clock, a vector signal source, a balun, an RF driver amplifier, an IQ electro-optic modulator, a laser source, a bias power supply controller, an intensity electro-optic modulator, a DC controller, an optical fiber power amplifier, and a transmitting chassis component; wherein the IQ electro-optic modulator and the intensity electro-optic modulator are interchangeable components. The vector signal source uses a vector signal generator, which can simulate differential IQ output and additive Gaussian white noise to perform communication bit error rate testing. The IQ electro-optic modulator is a 1550nm IQ electro-optic modulator, the intensity electro-optic modulator is a 1064nm intensity electro-optic modulator, and the optical fiber power amplifier is a 1064nm optical fiber power amplifier. The vector signal source is the generation of the test platform signal source, and the analog differential IQ output port located on the rear panel outputs a vector modulated signal for 1550nm vector modulation. The balun is used to realize differential to single-ended conversion of the RF signal, and the analog differential IQ baseband signal is respectively connected to two baluns after being led out to convert it into a single-ended IQ signal. The IQ electro-optic modulator is used to perform vector modulation on the optical signal passing through the modulator using the externally input RF IQ modulation signal. The bias power supply controller is a dedicated power supply for the modulator. Due to the high-speed characteristics of the modulator, it should be noted that the bias power supply controller cannot be powered by an ordinary DC power supply and needs to be powered by a dedicated power supply controller. The RF driver amplifier is used to enhance the input signal to a sufficiently high level to drive the RF output load. The laser source is used to provide a 1550nmCW or 1064nmCW continuous initial light source for the platform transmitter. The GNSS disciplined clock is used for frequency synchronization and geolocation. The transmitter chassis assembly includes a first chassis, an industrial computer, a display, a mouse, a keyboard, a first chassis power supply, and a first chassis fan. The transmitter chassis assembly is mainly used to control the system running software. The industrial computer in the transmitter chassis assembly is an industrial computer used to store and run system software.

[0049] In a preferred embodiment, the optical servo platform of the transmitting system includes an optical fiber power amplifier, a first polarization controller, a second polarization controller, a first collimator, a second collimator and a transmitting platform component; wherein the first polarization controller and the first collimator correspond to the IQ electro-optic modulator; and the second polarization controller and the second collimator correspond to the intensity electro-optic modulator. The first polarization controller is a 1550nm polarization controller, and the second polarization controller is a 1064nm polarization controller. The first collimator is a 1550nm collimator, and the second collimator is a 1064nm collimator. The first collimator and the second collimator are used to collimate the optical path, so that the divergent optical path becomes a parallel optical path. The first polarization controller and the second polarization controller are used to control the polarization state of the light source at the input end of the detector. The optical fiber power amplifier is used to amplify the modulated optical signal power output by the electro-optic modulator, increase the optical output power of the transmitting end, and increase the optical communication distance. The transmitting platform component includes a first turntable and a first tripod, wherein the first turntable is used to control the position of the transmitting end, and the first tripod is used to support the optical servo platform of the transmitting system. In general, the launch system optical servo platform consists of multiple components that work together to stabilize and control the transmission of optical signals. Different components correspond to different functions, such as polarization control, collimated optical path, and optical power amplification. The launch platform components are used to support and adjust the position and angle of the launch system. The configuration and design of these components are intended to improve the stability and transmission performance of the optical signal.

[0050] In a preferred embodiment, the receiving system component includes an optical-to-electrical converter, a down-converter, an oscilloscope, a GNSS disciplined clock, a filter, and a receiving chassis component. Among them, the oscilloscope is used to perform spectrum analysis and demodulation analysis on the collected signal. The optical-to-electrical converter is used to move the modulated signal on the received modulated optical signal to the radio frequency and output it so that the radio frequency signal analysis device can process it. The down-converter is used to reduce the carrier frequency of the signal or directly remove the carrier frequency to obtain the baseband signal. The receiving chassis component includes a second chassis, a second chassis power supply, and a second chassis fan, and the receiving chassis component is used to provide hardware support for the receiving system component. In general, the receiving system component performs signal analysis and demodulation analysis through an oscilloscope, the optical-to-electrical converter converts the modulated optical signal into a radio frequency signal, the down-converter is used to process the frequency of the signal, and the receiving chassis component provides hardware support and protection. These components work together to receive, process, and analyze the optical signal transmitted from the optical servo platform of the transmitting system.

[0051] In a preferred embodiment, the optical servo platform of the receiving system includes a first coupling mirror, a second coupling mirror, a fiber low noise amplifier and a receiving platform assembly. The first coupling mirror is a 1550nm coupling mirror, and the second coupling mirror is a 1064nm coupling mirror. The first coupling mirror and the second coupling mirror are used to converge multiple beams of different lasers into one optical path to couple the light beams passing through the collimator. The fiber low noise amplifier is an all-optical amplifier for signal amplification. The receiving platform assembly includes a second turntable and a second tripod, wherein the second turntable is used to control the position of the receiving end, and the second tripod is used to support the optical servo platform of the receiving system. In general, the optical servo platform of the receiving system converges multiple beams of different lasers into one optical path through the first coupling mirror and the second coupling mirror, the fiber low noise amplifier is used to amplify the received optical signal, and the receiving platform assembly provides support and adjusts the position and angle of the receiving system. The configuration and design of these components are intended to achieve stable reception and processing of the optical signal of the transmitting system.

[0052] In a preferred embodiment, the data communication system also includes auxiliary test tools, which include a frequency doubling card, an optical power meter, and laser protective glasses; the auxiliary test tools are used to verify equipment indicators and perform system performance tests. The frequency doubling card is used to test and verify the frequency doubling performance of the equipment, that is, to double the frequency of the input signal. Through the frequency doubling card, it is possible to check whether the equipment can correctly multiply the input signal and ensure that the frequency conversion function of the equipment is normal. The optical power meter is used to measure the power of the optical signal to ensure that the intensity of the optical signal meets the system requirements. The optical power meter can help calibrate and verify the optical signal to ensure that the signal intensity of the system is stable and meets expectations during transmission. The laser protective glasses are used to protect operators and equipment from laser beams. The laser beam has high energy and focusing properties. The use of laser protective glasses can effectively prevent the laser beam from damaging human eyes and equipment. In general, these auxiliary test tools play a role in verifying equipment performance, testing system performance, and protecting operators and equipment in the data communication system. They ensure the normal operation and safety of the data communication system through testing and protection means.

[0053] A data communication method using optical transmission in free space, a data communication system using optical transmission in free space, a signal sending method and a signal receiving method;

[0054] The specific steps of the signal sending method are as follows:

[0055] A1, using GNSS to tame the clock signal of the clock synchronization system;

[0056] A2, using a vector signal source to generate a high-frequency signal as a modulation source for the optical signal;

[0057] A3, using a balun to convert the differential IQ baseband signal into a single-ended IQ signal, and amplifying it through an RF driver amplifier; or using an RF driver amplifier to amplify the input signal to a high enough level to drive the RF output load, and modulating the signal through an intensity modulator;

[0058] A4, using a laser source to provide an initial light source;

[0059] A5, using an IQ electro-optical modulator or an intensity electro-optical modulator to convert the electrical signal into an optical signal and modulate it for transmission;

[0060] A6, using the bias power supply controller to provide stable voltage and current for the IQ electro-optic modulator; using the DC controller to control the output of the DC power supply to ensure the normal operation of the intensity electro-optic modulator;

[0061] A7, uses fiber optic amplifier to amplify optical signals, enhancing transmission distance and signal quality;

[0062] The signal receiving method is as follows:

[0063] S1, after the optical signal is received, it is converted into an electrical signal through a photoelectric converter;

[0064] S2, using a down converter to reduce the frequency of the high frequency signal;

[0065] S3, using an oscilloscope to observe and analyze the signal waveform;

[0066] S4, using the GNSS disciplined clock to synchronize the clock signal of the receiving system;

[0067] S5, uses optical fiber low noise amplifier to amplify optical signals and enhance the quality of received signals;

[0068] S6, the filter filters out unnecessary signal components and improves the purity of the signal.

[0069] In the description of the present invention, it is necessary to understand that the terms "coaxial", "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "top", "inside", "front", "center", "both ends" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0070] In the present invention, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation" and "screw-on" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0071] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A data communication system utilizing free-space optical transmission, characterized in that: It includes a transmitting terminal system and a receiving terminal system; The transmitting subsystem includes a transmitting system component and a transmitting system optical servo platform; the components in the transmitting system component work together to generate and send optical signals; the transmitting system component can achieve operation in different bands by replacing components; the transmitting system optical servo platform is used to control and stabilize the transmission of optical signals; The transmitting system components include a GNSS taming clock, a vector signal source, a balun, an RF driver amplifier, an IQ electro-optic modulator, a laser source, a bias power supply controller, an intensity electro-optic modulator, a DC controller, an optical fiber power amplifier, and a transmitting chassis component; wherein the IQ electro-optic modulator and the intensity electro-optic modulator are interchangeable components; the GNSS taming clock is connected to the vector signal source, the vector signal source is connected to the balun or the RF driver amplifier, the balun is connected to the IQ electro-optic modulator, the laser source is connected to the IQ electro-optic modulator or the intensity electro-optic modulator, the bias power supply controller is connected to the IQ electro-optic modulator, and the RF driver amplifier is connected to The optical servo platform of the transmitting system includes an optical fiber power amplifier, a first polarization controller, a second polarization controller, a first collimator, a second collimator and a transmitting platform component; wherein the first polarization controller and the first collimator correspond to the IQ electro-optical modulator; the second polarization controller and the second collimator correspond to the intensity electro-optical modulator; the first polarization controller or the second polarization controller is connected to the optical fiber power amplifier, the first collimator is connected to the first polarization controller, and the second collimator is connected to the second polarization controller; The receiving subsystem includes a receiving system component and a receiving system optical servo platform; the receiving system component is used to receive, process and analyze the optical signal transmitted by the transmitting system optical servo platform, and the receiving system optical servo platform is used to stabilize and control the received optical signal; The receiving system components include an optoelectronic converter, a downconverter, an oscilloscope, a GNSS disciplined clock, a filter and a receiving chassis component; the receiving system optical servo platform includes a first coupling mirror, a second coupling mirror, an optical fiber low noise amplifier and a receiving platform component; the oscilloscope is connected to the GNSS disciplined clock, the downconverter is connected to the oscilloscope, the optoelectronic converter is connected to the downconverter, the optical fiber low noise amplifier is connected to the downconverter, the first coupling mirror or the second coupling mirror is connected to the optical fiber low noise amplifier, the first collimator is connected to the first coupling mirror, and the second collimator is connected to the second coupling mirror; the oscilloscope is used to filter out unnecessary signal components.

2. A data communication system using free space optical transmission according to claim 1, characterized in that: The transmitting chassis assembly includes a first chassis, an industrial computer, a display, a mouse, a keyboard, a first chassis power supply and a first chassis fan.

3. A data communication system using free space optical transmission according to claim 1, characterized in that: The launch platform assembly includes a first turntable and a first tripod, wherein the first turntable is used to control the position of the launch end, and the first tripod is used to support the optical servo platform of the launch system.

4. A data communication system using free space optical transmission according to claim 1, characterized in that: The receiving chassis assembly includes a second chassis, a second chassis power supply, and a second chassis fan.

5. A data communication system using free space optical transmission according to claim 1, characterized in that: The receiving platform assembly includes a second turntable and a second tripod, wherein the second turntable is used to control the position of the receiving end, and the second tripod is used to support the optical servo platform of the receiving system.

6. A data communication system using free space optical transmission according to claim 1, characterized in that: The data communication system also includes auxiliary test tools, which include a frequency multiplier card, an optical power meter, and laser protective glasses; the auxiliary test tools are used to verify equipment indicators and perform system performance tests.

7. A data communication method using free space optical transmission, used in a data communication system using free space optical transmission as claimed in any one of claims 1 to 6, characterized in that: Including a signal sending method and a signal receiving method; The specific steps of the signal sending method are as follows: A1, using GNSS to tame the clock signal of the clock synchronization system; A2, using a vector signal source to generate a high-frequency signal as a modulation source for the optical signal; A3, using a balun to convert the differential IQ baseband signal into a single-ended IQ signal, and amplifying it through an RF driver amplifier; or using an RF driver amplifier to amplify the input signal to a level high enough to drive the RF output load, and modulate the signal through an intensity electro-optic modulator; A4, using a laser source to provide an initial light source; A5, using an IQ electro-optical modulator or an intensity electro-optical modulator to convert the electrical signal into an optical signal and modulate it for transmission; A6, using the bias power supply controller to provide stable voltage and current for the IQ electro-optic modulator; using the DC controller to control the output of the DC power supply to ensure the normal operation of the intensity electro-optic modulator; A7, uses fiber optic amplifier to amplify optical signals, enhancing transmission distance and signal quality; The signal receiving method is as follows: S1, after the optical signal is received, it is converted into an electrical signal through a photoelectric converter; S2, using a down converter to reduce the frequency of the high frequency signal; S3, using an oscilloscope to observe and analyze the signal waveform; S4, using the GNSS disciplined clock to synchronize the clock signal of the receiving system; S5, uses optical fiber low noise amplifier to amplify optical signals and enhance the quality of received signals; S6, the filter filters out unnecessary signal components and improves the purity of the signal.

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