Satellite-borne laser communication system

Abstract

The invention relates to a satellite-borne laser communication system, the system comprises a comprehensive management unit and N laser terminals, the comprehensive management unit is used for electronic modulation and demodulation and data processing, and the comprehensive management unit comprises an optical transceiver module, a digital baseband module and a data routing module; the N laser terminals are used for transmitting and receiving optical signals, and each laser terminal comprises an optical antenna module and a light amplification module; the number of the integrated management units and the number of the laser terminals are sum, wherein N is a natural number greater than 1. The invention provides a '1 + N' function and interface division method and provides a satellite-borne laser communication system which is completed by matching one comprehensive management unit and N miniaturized laser terminals through the idea of'merging similar items + integrated management and control 'and'photoelectric separation', so that each laser terminal does not independently have a photoelectric integrated laser communication function any more, and the communication efficiency of the satellite-borne laser communication system is improved. The laser terminal is responsible for transmitting and receiving optical signals, and the comprehensive management unit is responsible for electronic modulation and demodulation and data processing.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser inter-satellite link, and relates to a spaceborne laser communication system. BACKGROUND

[0002] A conventional laser inter-satellite link device is generally composed of an electronic unit, an optoelectronic conversion and control unit, an optical power amplification unit, a transceiving optical path and a rotating mechanism unit. With the development of network constellation, the demand for laser terminals carried by a single satellite has increased to three or more (for example, one in front and one behind the same orbit, and one in a different orbit), but limited by the spaceborne capacity, the miniaturization of laser inter-satellite link is in demand. SUMMARY

[0003] To solve at least part of the above problems in the prior art, the present application provides a spaceborne laser communication system, which proposes to carry multiple laser inter-satellite link devices by a single satellite, and is completed by one comprehensive management unit and N miniaturized laser terminals, so as to meet the demand for simultaneous communication of multiple terminals and successfully achieve the goal of miniaturization and light weight.

[0004] The present application provides a spaceborne laser communication system, comprising:

[0005] a comprehensive management unit for electronic modulation and demodulation and data processing, the comprehensive management unit comprising an optical transceiving module, a digital baseband module and a data routing module; and

[0006] a laser terminal for optical signal transceiving, the laser terminal comprising an optical antenna module and an optical amplification module; the number of the comprehensive management unit and the laser terminal is one and

[0007] N, wherein N is a natural number greater than 1.

[0008] Further, the comprehensive management unit and the laser terminal have a bidirectional communication interface.

[0009] Further, the optical transceiving module comprises:

[0010] an electro-optical modulator; and

[0011] an optical coherent demodulation component for demodulating the received optical signal into an electrical signal for subsequent processing by the digital baseband module and the like.

[0012] Further, the optical transceiving module is an optical coherent transmitting module and an optical coherent receiving module.

[0013] Further, the optical transceiver module further comprises a seed light emitting component, a light wavelength switching component and a light amplitude detection component. The light emitting component comprises a seed laser, an optical switch and an optical coupler, which are used to realize the light path switching function, realize the multi-light path shared seed laser and improve the efficiency of backup. The light wavelength switching component can change the wavelength of the optical signal according to the communication demand, can realize the function of wavelength division multiplexing and the like, and improve the capacity and flexibility of the communication system; the light amplitude detection component comprises a light amplitude detector, detects the intensity of the received optical signal, obtains the amplitude information of the optical signal, and feeds back to the tracking control module (the coherent demodulation component and the light amplitude detector are the same component).

[0014] Further, the optical transceiver module integrates the electro-optical modulator, the optical coherent demodulation component, the optical emitting component, the optical wavelength switching component, the optical amplitude detection component and the optical path, and the coupler and the optical switch in the optical emitting component can smoothly complete the multi-switching (switching of the wavelength channel and the optical path channel of the optical signal) and the backup relationship.

[0015] Further, the digital baseband module comprises an encoding component and a decoding component. The encoding component and the decoding component are used in the electrical signal domain, which is consistent with the traditional communication.

[0016] Further, the data routing module comprises a data routing forwarding component, a laser engineering telemetry storage and sending component, a link establishment task control component and a satellite platform communication component; the data routing module mainly completes the routing forwarding control function, the link establishment task planning function, the interaction of the management data and the communication data with the satellite platform through the 1553B bus and the like, and the above functions are realized by the same CPU.

[0017] Further, the optical antenna module comprises an optical axis calibration and calibration data management component, an optical signal emitting processing component, a polarization state control component, a coarse tracking control component, a fine tracking control component, an optical detection and capture component (four-quadrant detector, infrared focal plane camera) and a light amplitude nutation control component. The optical antenna module undertakes the optical axis calibration and calibration data storage and sending, the modulated signal light amplification and emission, the polarization state switching, the coarse / fine tracking control, the optical detection and capture and the light amplitude nutation control solved by the integrated management unit. The polarization state modulation mainly adopts the switching in and out of the control 1 / 4 wave plate to realize the polarization state switching.

[0018] Further, the optical axis calibration and calibration data management component comprises:

[0019] An optical axis calibration device is used to calibrate the optical axis pointing of the optical antenna, correct the pointing deviation caused by the satellite attitude, thermal deformation and the like, and the optical axis calibration device comprises a calibration light source (such as a laser diode), an optical prism, an optical mirror and a calibration detector (such as a CCD camera); and

[0020] The calibration data storage and transmission device is used to store the error data collected during the optical axis calibration process and send it to the integrated management unit through the interface for subsequent tracking and control parameter updates.

[0021] Furthermore, the optical signal transmission processing component includes:

[0022] A modulation signal optical amplification device is used to amplify the power of the modulated optical signal output by the optical transceiver module, thereby improving the transmission distance and attenuation resistance of the optical signal; and

[0023] A transmitting optical array is used to focus and collimate an amplified optical signal (transmitted / received optical signal) into a narrow beam for transmission, thereby reducing energy divergence during spatial transmission. The transmitting optical array includes a lens group and a collimator.

[0024] Furthermore, the polarization state control component includes:

[0025] Polarization modulators are used to change the polarization state of optical signals (such as linear polarization direction, circular polarization mode switching), optimize the signal's anti-interference capability during spatial transmission, and

[0026] A polarization state monitoring device, used to detect the polarization state of an optical signal in real time, providing feedback data for polarization state switching; and / or

[0027] The coarse tracking control component includes a wide-angle detector, including a four-quadrant detector (QPD) or an avalanche photodiode (APD); the fine tracking control component includes a fast-reflecting mirror; and / or

[0028] Furthermore, the optical amplification module includes a low-noise amplification component, which includes an optical amplifier, specifically a semiconductor optical amplifier (SOA) or an erbium-doped fiber amplifier (EDFA). The optical amplification module is responsible for receiving and amplifying low-noise light; and / or

[0029] The N-channel optical amplifiers are individually packaged, facilitating thermal control layout design. This individual packaging avoids multi-channel thermal coupling. Furthermore, if a thermal control fault occurs in one channel, the faulty module can be replaced on-orbit without affecting the operation of other channels, reducing overall satellite maintenance costs.

[0030] The present invention has at least the following beneficial effects: 1) The present invention proposes a "1+N" function and interface division method through the idea of ​​"merging similar items + integrated management and control" and "photoelectric separation". The traditional independent N laser inter-satellite link devices are changed to be completed by one integrated management unit and N miniaturized laser terminals. So that each laser terminal no longer has independent photoelectric integrated laser communication function. The laser terminal is responsible for optical signal transmission and reception, and the integrated management unit (main control unit) is responsible for electronic modulation and demodulation and data processing; 2) The present invention breaks the original idea of ​​independent design of laser terminals. It adopts integrated and standardized design, integrating the optical transceiver module, digital baseband module and data routing module into one design, reducing the cost of a single set, and improving the system reliability; 3) The thermal control of optical amplifiers is the difficulty of long-term high reliability operation of laser inter-satellite links in orbit. To solve this difficulty, the N optical amplifiers are packaged separately, which facilitates the thermal control design of the whole satellite. Attached Figure Description

[0031] To further illustrate the above and other advantages and features of the various embodiments of the present invention, a more specific description of the embodiments of the invention will be presented with reference to the accompanying drawings. It is to be understood that these drawings depict only typical embodiments of the invention and are therefore not intended to limit its scope. In the drawings, identical or corresponding parts will be indicated by identical or similar reference numerals for clarity.

[0032] Figure 1 A schematic diagram illustrating the functional interface division of a spaceborne laser communication system in some embodiments of the present invention is shown. Detailed Implementation

[0033] It should be noted that the components in the accompanying drawings may be shown exaggerated for illustrative purposes and may not be to scale.

[0034] In this invention, the various embodiments are merely intended to illustrate the solutions of the invention and should not be construed as limiting.

[0035] In this invention, unless otherwise specified, the quantifiers “a” and “one” do not exclude scenarios involving multiple elements.

[0036] It should also be noted that, in the embodiments of the present invention, only a portion of the parts or components may be shown for clarity and simplicity. However, those skilled in the art will understand that, under the teachings of the present invention, the required parts or components can be added as needed for specific scenarios.

[0037] It should also be noted that within the scope of this invention, the terms "same", "equal", and "equal to" do not mean that the two values ​​are absolutely equal, but allow for a certain reasonable error. In other words, the terms also cover "substantially the same", "substantially equal", and "substantially equal to".

[0038] It should also be noted that in the description of this invention, the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not explicitly or implicitly suggest that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0039] Furthermore, the embodiments of the present invention describe the process steps in a specific order. However, this is only for the convenience of distinguishing each step, and is not a limitation on the order of each step. In different embodiments of the present invention, the order of each step can be adjusted according to the process.

[0040] The following embodiment provides a spaceborne laser communication system, including an integrated management unit and laser terminals. The integrated management unit is used for electronic modulation and demodulation and data processing, and includes an optical transceiver module, a digital baseband module, and a data routing module. The laser terminals are used for optical signal transmission and reception, and include an optical antenna module and an optical amplification module. The number of integrated management units and laser terminals is one and N, respectively, where N is a natural number greater than 1. Both the integrated management unit and the laser terminals have bidirectional communication interfaces. Figure 1 The diagram illustrates the "1+N" functional interface division of a spaceborne laser communication system. It shows that the signal originates from the satellite platform, undergoes data routing, forwarding, and storage processing via the data routing module, and is encoded by the digital baseband module. The optical signal is then coherently transmitted from the optical transceiver module of the integrated management unit, amplified by the laser terminal, and optically transmitted. Upon reception, the optical signal is optically received and amplified by the laser terminal, then coherently received by the optical transceiver module, decoded by the digital baseband module, processed by the data routing module, and transmitted to the satellite platform. This demonstrates the functional interface division of each module in the spaceborne laser communication system and the transmission and conversion process between optical and electrical signals.

[0041] The optical transceiver module integrates optical transceiver components and optical paths, enabling seamless multi-channel switching and backup. Thermal control of optical amplifiers is a key challenge for the long-term, high-reliability operation of laser inter-satellite links in orbit. To address this challenge, N optical amplifiers are individually packaged, facilitating overall satellite thermal control design. Individual packaging avoids multi-channel thermal coupling. Furthermore, if a thermal control failure occurs in one channel, the faulty module can be replaced in orbit without affecting other channels, reducing overall satellite maintenance costs. Breaking away from the original approach of independent laser terminal design, an integrated and standardized design is adopted, combining the optical transmit / receive module, baseband module, and routing module into a single unit, reducing unit cost while improving system reliability.

[0042] While some embodiments of the present invention have been described in this application, those skilled in the art will understand that these embodiments are merely illustrative. Numerous variations, alternatives, and improvements will arise in those skilled in the art under the teachings of this invention without departing from its scope. The appended claims are intended to define the scope of the invention and thereby cover methods and structures within the scope of the claims themselves and their equivalents.

Claims

1. A spaceborne laser communication system, characterized in that, include: An integrated management unit for electronic modulation / demodulation and data processing includes an optical transceiver module, a digital baseband module, and a data routing module; and A laser terminal is used for optical signal transmission and reception. The laser terminal includes an optical antenna module and an optical amplification module. The number of the integrated management unit and the number of laser terminals are one and N, respectively, where N is a natural number greater than 1.

2. The spaceborne laser communication system according to claim 1, characterized in that, The optical transceiver module includes: Electro-optic modulators; and An optical coherent demodulation component is used to demodulate received optical signals into electrical signals.

3. The spaceborne laser communication system according to claim 1, characterized in that, The optical transceiver module also includes a seed light emission component, an optical wavelength switching component, and an optical amplitude detection component.

4. The spaceborne laser communication system according to claim 1, characterized in that, The digital baseband module includes an encoding component and a decoding component.

5. The spaceborne laser communication system according to claim 1, characterized in that, The data routing module includes a data routing and forwarding component, a laser engineering telemetry storage and transmission component, a link establishment task control component, and a communication component with the satellite platform.

6. The spaceborne laser communication system according to claim 1, characterized in that, The optical antenna module includes an optical axis calibration and calibration data management component, an optical signal transmission processing component, a polarization state control component, a coarse tracking control component, a fine tracking control component, an optical detection and capture component, and an optical amplitude nutation control component.

7. The spaceborne laser communication system according to claim 6, characterized in that, The optical axis calibration and calibration data management component includes: An optical axis calibration device for calibrating the optical axis pointing of an optical antenna, the device comprising a calibration light source, an optical prism, an optical mirror, and a calibration detector; and The calibration data storage and transmission device is used to store error data collected during the optical axis calibration process and send it to the integrated management unit.

8. The spaceborne laser communication system according to claim 6, characterized in that, The optical signal transmission processing component includes: A modulation signal optical amplification device, used to amplify the power of the modulated optical signal output from the optical transceiver module; and An emitting optical array is used to focus and collimate an amplified optical signal into a narrow beam for emission. The emitting optical array includes a lens group and a collimator.

9. The spaceborne laser communication system according to claim 6, characterized in that, The polarization state control component includes: Polarization modulators are used to change the polarization state of optical signals, and A polarization state monitoring device, used to detect the polarization state of an optical signal in real time, providing feedback data for polarization state switching; and / or The coarse tracking control component includes a wide-angle detector; the fine tracking control component includes a fast-reflecting mirror; and / or The optical detection and capture component includes: A photodetector array, used to detect optical signals; and A capture optical path array for focusing spatial light signals onto a detector surface, the capture optical path array including optical lenses and filters; and / or The light amplitude nutation control component includes a nutation sensor and a micro-vibration actuator.

10. The spaceborne laser communication system according to claim 1, characterized in that, The optical amplification module includes a low-noise amplification component, which includes an optical amplifier, wherein the optical amplifier includes either an SOA or an EDFA-doped optical amplifier; and / or The N-channel optical amplifiers are individually packaged.

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