Multi-path receiving and transmitting integrated satellite laser communication system and method based on optical switch

Abstract

The invention relates to a photoelectric communication system, in particular to a multi-path receiving and transmitting integrated satellite laser communication system and method based on an optical switch, and aims to solve the problems that the integration level of an existing communication system is not high enough, the signal receiving and transmitting integrated function and the signal wavelength multiplexing and demultiplexing function cannot be achieved, and the communication efficiency is low. A satellite communication system is large in size; and ultra-high-speed signal transmission is difficult to realize. The system comprises a main control unit and a power supply unit which are electrically connected with an external satellite platform, and a high-speed optical transceiver unit, an optical switch unit, an optical transmitting branch unit and an optical receiving branch unit which are respectively connected with the main control unit and the power supply unit, the high-speed optical transceiver unit comprises m high-speed optical modules capable of transmitting and receiving optical signals; the light emitting branch unit comprises n light emitting branches; the light receiving branch unit comprises n light receiving branches. The system is high in integration level, does not need multiple times of photoelectric conversion, and is high in link reliability.

Description

Technical Field The present invention relates to an optoelectronic communication system, and in particular to a multi-channel transceiver-integrated satellite laser communication system and method based on an optical switch. Background Art In the past few decades, microwave communication has been the main way of information exchange between satellites and the ground. It transmits information through electromagnetic waves in the microwave frequency band (usually between 300MHz and 300GHz). Microwave communication has the advantages of low cost, wide coverage and strong penetration. With the continuous improvement of the resolution and accuracy of on-board equipment (such as high-definition image capture systems, high-precision sensors and spectrometers, etc.), the amount of data that needs to be transmitted between satellites and the ground has exploded. At present, the amount of data generated by satellites every day can reach hundreds of GB (gigabytes) or even TB (terabytes). Therefore, this field has put forward higher requirements on the bandwidth and capacity of space information networks. Limited by carrier spectrum resources, the single-channel transmission rate of microwave communication is usually in the order of hundreds of Mbps (megabits per second), which can no longer meet the current needs of massive satellite data transmission. Laser communication uses laser beams as a carrier for information transmission, and transmits information by modulating the wavelength, frequency, phase or intensity of the laser. Its frequency can reach the THz (terahertz) level, which can achieve extremely high transmission rates (such as 10Gbps, 100Gbps). The use of wavelength division multiplexing technology can further increase the transmission rate. Based on its advantages such as large bandwidth, fast speed, low latency, good confidentiality, strong anti-interference ability, small size and light weight, laser communication is currently in a rapid development stage, especially showing great potential in the fields of deep space communication and satellite communication. Currently, satellite laser communication networks are being built at a rapid pace, but the main problems are:

[0001] For multiple laser communication system terminals on each satellite, in order to improve reliability, multi-channel backup of core components (such as high-cost high-speed optical modules) is often required, resulting in repeated use of core components and waste of resources;

[0002] The satellite-borne laser communication rates in space information networks are still mainly 5Gbps and 10Gbps, and ultra-high-speed transmission such as 100Gbps is still in the experimental stage;

[0003] The communication system and switching system are separate, and there is a problem of high power consumption caused by multiple photoelectric conversions. In addition, the system is large in size, low in integration, and low in utilization of onboard resources. Chinese patent CN114024798A discloses an integrated satellite-borne microwave optoelectronic hybrid communication exchange system and method, but the problems with the prior art are: the system integration is not high enough, and it is unable to realize the integrated signal transmission and reception function, as well as the signal wavelength multiplexing and demultiplexing function, which easily leads to a large satellite communication system and difficulty in achieving ultra-high-speed signal transmission. Summary of the invention The purpose of the present invention is to solve the problem that the existing communication system is not integrated enough and cannot realize the functions of signal transmission and reception as well as signal wavelength multiplexing and demultiplexing, which easily leads to the problem that the satellite communication system is bulky and difficult to achieve ultra-high-speed signal transmission. A multi-channel transceiver satellite laser communication system and method based on optical switches are provided. To achieve the above purpose, the technical solution provided by the present invention is: A multi-channel transceiver satellite laser communication system based on optical switches, which is special in that: It includes a main control unit and a power supply unit electrically connected to the external satellite platform respectively, and a high-speed optical transceiver unit, an optical switch unit, an optical transmission branch unit and an optical reception branch unit respectively connected to the main control unit and the power supply unit; the main control unit and the power supply unit are connected to each other; The high-speed optical transceiver unit is used to generate and modulate multiple high-speed optical signals according to the transmission instructions of the main control unit, and / or demodulate the received optical signals and send them to the main control unit, including m high-speed optical modules that can transmit and receive optical signals, m>1, m is an integer, and each high-speed optical module is respectively connected to the input end and output end corresponding to the optical switch unit; The optical transmission branch unit includes n optical transmission branches, n>1, n is an integer, the input end of each optical transmission branch is connected to the corresponding output end of the optical switch unit, the first output end is used to send an optical signal, and the second output end is connected to the corresponding input end of the optical switch unit; each optical transmission branch is used to multiplex, amplify and transmit 2p optical signals generated after modulation by the high-speed optical module in the high-speed optical transceiver unit into free space, p>1, p is an integer; The optical receiving branch unit includes n optical receiving branches, the first input end of each optical receiving branch is used to receive an external optical signal, the second input end is connected to the corresponding output end of the optical switch unit, and the output end is connected to the corresponding input end of the optical switch unit; each optical receiving branch is used to perform low-noise amplification on the weak optical signal received in the free space, and then demultiplex to generate 2p optical signals and transmit them to the high-speed optical transceiver unit through the optical switch unit for demodulation; Define the number of input ports of the optical switch unit as S in , the number of output ports is S out , then S in ≥m+n+2pn,S out≥m+n+2pn; The main control unit is used to control the high-speed optical transceiver unit, the optical switch unit, the optical transmitting branch unit and the optical receiving branch unit to receive or send signals according to the task instructions issued by the satellite platform; the power supply unit is used to use the electric energy provided by the satellite platform to power the main control unit, the high-speed optical transceiver unit, the optical switch unit, the optical transmitting branch unit and the optical receiving branch unit. Furthermore, each of the optical transmission branches comprises a multi-stage multiplexing module whose input end is connected to the output end corresponding to the optical switch unit, a transmitter coupler whose input end is connected to the output end of the multi-stage multiplexing module, a power amplifier whose input end is connected to the first output end of the transmitter coupler, and a transmitter machine whose input end is connected to the output end of the power amplifier; the second output end of the transmitter coupler is connected to the corresponding input end of the optical switch unit; The multi-stage multiplexing module is used to wavelength-division multiplex 2p optical signals into one communication line; the power amplifier is used to perform high-power amplification on the optical signal; the transmitting end coupler is used to implement communication link self-test; and the transmitting end is used to transmit the optical signal into free space. Furthermore, each of the optical receiving branches includes a receiving end, a preamplifier whose input end is connected to the output end of the receiving end, a receiving end coupler whose first input end is connected to the output end of the preamplifier, and a multi-stage demultiplexing module whose input end is connected to the receiving end coupler; the second input end of the receiving end coupler is connected to the corresponding output end of the optical switch unit; The receiving end is used to receive optical signals from free space; the preamplifier is used to perform low-noise amplification on weak signals in the received optical signals; the receiving end coupler is used to implement self-test of the communication link; and the multi-stage demultiplexing module is used to implement separate filtering of signals of different wavelengths. Furthermore, the optical switch unit and each high-speed optical module, the optical switch unit and each multi-stage multiplexing module, the optical switch unit and each multi-stage demultiplexing module, the multi-stage multiplexing module, the transmitting end coupler, the power amplifier and the transmitting end machine in each optical transmitting branch, and the receiving end machine, the preamplifier, the receiving end coupler and the multi-stage demultiplexing module in each optical receiving branch are all connected by optical fibers. Furthermore, the modulation mode adopted by the high-speed optical module is OOK, BPSK, QPSK, DP-QPSK, 8-QAM or 16-QAM. Further, the modulation mode of the high-speed optical module is DP-QPSK, and includes a transmitting module, a receiving module, and a driving control circuit electrically connected to the transmitting module, the receiving module, the main control unit and the power supply unit; The transmitting module includes a signal laser, a first polarization beam splitter whose input end is connected to an output end of the signal laser, a first IQ modulator whose input end is connected to a first output end of the first polarization beam splitter, a second IQ modulator whose input end is connected to a second output end of the first polarization beam splitter, and a polarization beam combiner whose input end is respectively connected to an output end of the first IQ modulator and an output end of the second IQ modulator; the signal laser is used to transmit an optical signal of a preset wavelength according to a transmitting instruction of a main control unit, the first IQ modulator and the second IQ modulator are used to modulate the optical signal, and the output end of the polarization beam combiner is used to send the modulated optical signal to an optical switch unit; The receiving module includes a local oscillator laser, a third polarization beam splitter whose input end is connected to the output end of the local oscillator laser, a second polarization beam splitter, a first 90° mixer whose input end is respectively connected to the first output end of the second polarization beam splitter and the first output end of the third polarization beam splitter, a second 90° mixer whose input end is respectively connected to the second output end of the second polarization beam splitter and the second output end of the third polarization beam splitter, a first balanced detector whose input end is connected to the first output end of the first 90° mixer, a second balanced detector whose input end is connected to the second output end of the first 90° mixer, a third balanced detector whose input end is connected to the first output end of the second 90° mixer, and a A fourth balanced detector connected to the second output end of the second 90° mixer, an ADC module whose input end is respectively connected to the output ends of the first balanced detector, the second balanced detector, the third balanced detector and the fourth balanced detector, and a DSP module whose input end is connected to the output end of the ADC module; the input end of the second polarization beam splitter is used to receive an optical signal from the optical switch unit, the ADC module and the DSP module are used to demodulate the signal, the drive control circuit is used to drive and control the high-speed optical module, and at the same time load the original signal sent from the satellite platform data source into the transmitting module, and send the signal demodulated by the receiving module to the satellite platform data receiving end. Furthermore, the transmitter and receiver are both transceiver-integrated terminals, and the transceiver-integrated terminal includes a transceiver relay optical path connected to the output end of the power amplifier or the input end of the preamplifier, a transceiver antenna connected to the transceiver relay optical path, a PAT module electrically connected to the main control unit, and a mechanical turntable electrically connected to the PAT module; the transceiver relay optical path and the transceiver antenna are both arranged on the mechanical turntable; The transceiver antenna is used to transmit optical signals into free space or receive optical signals from free space; the transceiver relay optical path is used for coupling conversion between optical fiber signals and free space optical signals, and for beam shaping processing; the PAT module is used to control the rotation angle of the mechanical turntable, the transceiver direction of the transceiver antenna, and the galvanometer direction of the transceiver relay optical path, so as to realize the capture, tracking and aiming of the transceiver optical signals. Furthermore, the optical switch unit is a MEMS optical switch, a magneto-optical switch, an electro-optical switch or an MZI / MRR-based silicon-based on-chip optical switch. At the same time, the present invention also provides a multi-channel transceiver integrated satellite laser communication method based on an optical switch, which is special in that the multi-channel transceiver integrated satellite laser communication system based on an optical switch is adopted, including an optical signal transmitting method and an optical signal receiving method; The optical signal transmission method comprises the following steps: Step a1: the external satellite platform sends an optical signal transmission instruction to the main control unit according to actual needs, and the main control unit controls the high-speed optical transceiver unit, the optical switch unit and the optical transmission branch unit according to the optical signal transmission instruction; Step a2: The driving control circuit loads the original signal sent from the satellite platform data source into multiple high-speed optical modules in the high-speed optical transceiver unit to generate a modulated optical signal, and the modulated optical signal is transmitted to the optical switch unit through the corresponding input port; Step a3, the optical switch unit distributes the modulated optical signal to the corresponding optical transmission branch in the optical transmission branch unit through the corresponding output port; Step a4, the optical transmission branch multiplexes, amplifies and transmits the multiple modulated optical signals into free space to complete the optical signal transmission; The optical signal receiving method comprises the following steps: Step b1, the external satellite platform sends an optical signal receiving instruction to the main control unit according to actual needs, and the main control unit controls the high-speed optical transceiver unit, the optical switch unit and the optical receiving branch unit according to the optical signal transmitting instruction; Step b2: the optical receiving branch amplifies the optical signal received in the free space, demultiplexes it and transmits it to the optical switch unit; Step b3, the optical switch unit distributes the demultiplexed optical signal to the corresponding high-speed optical module in the high-speed optical transceiver unit through the corresponding output port; Step b4: The high-speed optical module demodulates the optical signal and transmits it to the satellite platform data receiving end to complete the optical signal reception. Furthermore, a multi-channel transceiver-integrated satellite laser communication method based on an optical switch also includes a communication link transmission bit error rate test method and a communication system self-test method; The communication link transmission bit error rate testing method comprises the following steps: Step c1, the external satellite platform sends a communication link transmission bit error rate test instruction to the main control units of the laser communication system A and the laser communication system B according to actual needs, and the main control unit of the laser communication system A controls the high-speed optical transceiver unit, the optical switch unit and the optical transmission branch unit according to the communication link transmission bit error rate test instruction; Step c2, the FPGA in the driving control circuit in the laser communication system A generates a pseudo-random binary sequence, which is sent to the laser communication system B via the high-speed optical transceiver unit, the optical switch unit, and the optical transmission branch unit; Step c3: After receiving the optical signal, the laser communication system B transmits the signal through its optical receiving branch unit and optical switch unit to the high-speed optical transceiver unit. The driving control circuit deframes, synchronizes and compares the signal, and then calculates the transmission bit error rate of the communication link. The communication system self-test method comprises the following steps: Step d1, the external satellite platform sends an optical signal transmission instruction to the main control unit according to actual needs, and the main control unit controls the high-speed optical transceiver unit, the optical switch unit and the optical transmission branch unit according to the optical signal transmission instruction; Step d2, turning off the power amplifier and the preamplifier; Step d3, configuring the connection relationship between the optical switch input and output ports, configuring the optical switch unit input corresponding to the second output of the transmitting end coupler to the optical switch unit output corresponding to the second input of the receiving end coupler; Step d4, the FPGA in the driving control circuit generates a pseudo-random binary sequence by itself, which is returned to the high-speed optical transceiver unit through the high-speed optical transceiver unit, the optical switch unit, the multi-stage multiplexing module and the transmitting end coupler in the optical transmitting branch unit, the optical switch unit, the receiving end coupler and the multi-stage demultiplexing module in the optical receiving branch unit, and the optical switch unit. After the driving control circuit deframes, synchronizes, and compares the signal, the self-test line bit error rate is calculated. Compared with the prior art, the present invention has the following beneficial effects: 1. The multi-channel transceiver integrated satellite laser communication system based on optical switch provided by the present invention is provided with an optical switch unit, which has high integration and does not require multiple photoelectric conversions, and can reduce the weight and volume of the satellite communication system. The optical switch unit is provided with multiple input ports and output ports to meet the needs of signal transmission; multiple high-speed optical modules are provided, each of which can realize the transceiver function of optical signals, and the link reliability of the communication system is high; 2. The multi-channel transceiver integrated satellite laser communication system based on optical switches provided by the present invention is provided with a multi-stage multiplexing module and a multi-stage demultiplexing module, realizing the multi-wavelength multiplexing function of the communication system; 3. The multi-channel transceiver-in-one satellite laser communication system based on optical switches provided by the present invention has a transmitter terminal and a receiver terminal that are both transceiver-in-one terminals, which reduces the manufacturing difficulty of the communication system and has high flexibility. 4. Compared with the existing single-wavelength transmission method, the multi-channel transceiver-transmitter satellite laser communication method based on optical switches provided by the present invention can simultaneously meet the needs of different links, different rates, and even high-speed (such as 100Gbps, 200Gbps, 400Gbps) service transmission and distribution, and the transmission rate is increased exponentially. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 It is a schematic diagram of an embodiment of a multi-channel transceiver-integrated satellite laser communication system based on an optical switch of the present invention; Figure 2 It is a schematic diagram of a high-speed optical module in an embodiment of a multi-channel transceiver-integrated satellite laser communication system based on an optical switch of the present invention; Figure 3 It is a schematic diagram of a transceiver-integrated terminal in an embodiment of a multi-channel transceiver-integrated satellite laser communication system based on an optical switch of the present invention; Description of reference numerals: 1-main control unit; 2-power supply unit; 3-high-speed optical transceiver unit, 31-high-speed optical module, 311-signal laser, 312-first polarization beam splitter, 313-first IQ modulator, 314-second IQ modulator, 315-polarization beam combiner, 316-local oscillator laser, 317-second polarization beam splitter, 318-third polarization beam splitter, 319-first 90° mixer, 3110-second 90° mixer, 3111-first balanced detector, 3112-second balanced detector, 3113-third balanced detector, 3114-fourth balanced detector, 31 15-ADC module, 3116-DSP module, 3117-drive control circuit; 4-optical switch unit; 5-optical transmitting branch unit, 51-optical transmitting branch, 511-multi-stage multiplexing module, 512-transmitting end coupler, 513-power amplifier, 514-transmitting end machine; 6-optical receiving branch unit, 611-receiving end machine, 6111-transmitting and receiving relay optical path, 6112-transmitting and receiving antenna, 6113-mechanical turntable, 6114-PAT module, 612-preamplifier, 613-receiving end coupler, 614-multi-stage demultiplexing module; 7-atmospheric or vacuum environment. DETAILED DESCRIPTION The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. A multi-channel transceiver satellite laser communication system based on optical switches, the schematic diagram of which can be found in Figure 1 ; It includes a main control unit 1 and a power supply unit 2 which are electrically connected to an external satellite platform respectively, and a high-speed optical transceiver unit 3, an optical switch unit 4, an optical transmission branch unit 5 and an optical reception branch unit 6 which are respectively connected to the main control unit 1 and the power supply unit 2; the main control unit 1 and the power supply unit 2 are connected to each other; The high-speed optical transceiver unit 3 is used to generate and modulate multiple high-speed optical signals according to the transmission instructions of the main control unit 1, and / or demodulate the received optical signals and send them to the main control unit 1, including six high-speed optical modules 31 that can receive and transmit optical signals, and each high-speed optical module 31 is respectively connected to the input end and output end corresponding to the optical switch unit 4; in actual application scenarios, high-speed optical modules 31 can be added to achieve backup. For example, a newly added backup high-speed optical module 31 is in a non-working state under normal circumstances, and can take over the backup work of three (the number of takeovers can also be adjusted in actual use) working high-speed optical modules 31 at the same time. When any one or more working high-speed optical modules 31 fail, The main control unit 1 can detect in time and transfer its original signal transmission task to the backup high-speed optical module 31, so as to ensure the correct transmission of the optical signal; when all the high-speed optical modules 31 used as backup are used up, if the existing high-speed optical module 31 in operation is damaged, the main control unit 1 will transfer its original signal transmission task to another working high-speed optical module 31. The high-speed optical module 31 to which the task is transferred will first perform its own task in sequence, and then perform the transferred task. Although this may prolong the completion time of the signal transmission task, it will not cause the interruption of a certain communication branch, thereby ensuring that each signal can eventually be correctly transmitted or received, greatly improving the link reliability of the communication system. The optical transmission branch unit 5 includes three optical transmission branches 51, the input end of each optical transmission branch 51 is connected to the corresponding output end of the optical switch unit 4, the first output end is used to send an optical signal, and the second output end is connected to the corresponding input end of the optical switch unit 4; each optical transmission branch 51 is used to multiplex, amplify and transmit the four optical signals generated after modulation by the high-speed optical module 31 in the high-speed optical transceiver unit 3 into free space; The optical receiving branch unit 6 includes three optical receiving branches 61, wherein the first input end of each optical receiving branch 61 is used to receive an external optical signal, the second input end is connected to the corresponding output end of the optical switch unit 4, and the output end is connected to the corresponding input end of the optical switch unit 4; each optical receiving branch 61 is used to perform low-noise amplification on the weak optical signal received in the free space, and then demultiplex to generate four optical signals and transmit them to the high-speed optical transceiver unit 3 through the optical switch unit 4 for demodulation; Define the number of input ports of the optical switch unit 4 as S in , the number of output ports is S out , then S in ≥21, S out ≥21; The main control unit 1 is used to control the high-speed optical transceiver unit 3, the optical switch unit 4, the optical transmission branch unit 5 and the optical receiving branch unit 6 to receive or send signals according to the task instructions issued by the satellite platform; the power supply unit 2 is used to use the electric energy provided by the satellite platform to power the main control unit 1, the high-speed optical transceiver unit 3, the optical switch unit 4, the optical transmission branch unit 5 and the optical receiving branch unit 6. The optical transmission branch unit 5 includes three optical transmission branches 51, each optical transmission branch 51 includes a multi-stage multiplexing module 511 whose input end is connected to the output end corresponding to the optical switch unit 4, a transmitting end coupler 512 whose input end is connected to the output end of the multi-stage multiplexing module 511, a power amplifier 513 whose input end is connected to the first output end of the transmitting end coupler 512, and a transmitting end machine 514 whose input end is connected to the output end of the power amplifier 513; the second output end of the transmitting end coupler 512 is connected to the corresponding input end of the optical switch unit 4; The multi-stage multiplexing module 511 is used to wavelength-division multiplex 2p optical signals into one communication line; the power amplifier 513 is used to perform high-power amplification on the optical signal; the transmitting end coupler 512 is used to implement self-test of the communication link; the transmitting end machine 514 is used to transmit the optical signal into free space, and the actual free space is the atmosphere or vacuum environment 7. The optical receiving branch unit 6 includes three optical receiving branches 61, each optical receiving branch 61 includes a receiving end 611, a preamplifier 612 whose input end is connected to the output end of the receiving end 611, a receiving end coupler 613 whose first input end is connected to the output end of the preamplifier 612, and a multi-stage demultiplexing module 614 whose input end is connected to the receiving end coupler 613; the second input end of the receiving end coupler 613 is connected to the output end of the optical switch unit 4; The receiving end 611 is used to receive optical signals from free space; the preamplifier 612 is used to perform low-noise amplification on weak signals in the received optical signals; the multi-stage demultiplexing module 614 is used to implement separate filtering of signals of different wavelengths; and the receiving end coupler 613 is used to implement self-test of the communication link. The signal direction during the self-test of the communication system is as follows: the transmitting end coupler 512 transmits a small part of the optical signal to the optical switch unit 4 through the second output end, and the optical switch unit 4 then transmits the optical signal to the optical switch unit 4 through the second input end of the receiving end coupler 613, and then enters the optical switch unit 4 through the multi-stage demultiplexing module 614, and finally transmits it to the corresponding high-speed optical module 31. This process realizes the on-orbit self-test of the system. The main control unit 1 is used to control the power supply unit 2, the high-speed optical transceiver unit 3, the optical switch unit 4, the optical transmission branch unit 5 and the optical reception branch unit 6 to receive or send signals according to the task instructions issued by the satellite platform; the power supply unit 2 is used to use the electric energy provided by the satellite platform to power the high-speed optical transceiver unit 3, the optical switch unit 4, the optical transmission branch unit 5 and the optical reception branch unit 6; the high-speed optical transceiver unit 3 is used for modulation and demodulation of multiple high-speed optical signals. The optical switch unit 4 and each high-speed optical module 31, the optical switch unit 4 and each multi-stage multiplexing module 511, the optical switch unit 4 and each multi-stage demultiplexing module 611, as well as the multi-stage multiplexing module 511, the transmitting end coupler 512, the power amplifier 513 and the transmitting end machine 514 in each optical transmitting branch 51, and the receiving end machine 611, the preamplifier 612, the receiving end coupler 613 and the multi-stage demultiplexing module 614 in each optical receiving branch 61 are all connected through optical fibers. In actual application scenarios, the modulation mode used by the high-speed optical module 31 is OOK, BPSK, QPSK, DP-QPSK, 8-QAM or 16-QAM. This embodiment takes the modulation mode DP-QPSK as an example to introduce the structure and principle of the high-speed optical module 31. Figure 2 The modulation mode of the high-speed optical module 31 is DP-QPSK, and it includes a transmitting module, a receiving module, and a driving control circuit 3117 electrically connected to the transmitting module, the receiving module, the main control unit 1 and the power supply unit 2; The transmitting module includes a signal laser 311, a first polarization beam splitter 312 whose input end is connected to the output end of the signal laser 311, a first IQ modulator 313 whose input end is connected to the first output end of the first polarization beam splitter 312, a second IQ modulator 314 whose input end is connected to the second output end of the first polarization beam splitter 312, and a polarization beam combiner 315 whose input end is respectively connected to the output end of the first IQ modulator 313 and the output end of the second IQ modulator 314; the signal laser 311 is used to transmit an optical signal of a preset wavelength according to a transmitting instruction of the main control unit 1, the first IQ modulator 313 and the second IQ modulator 314 are used to modulate the optical signal, and the output end of the polarization beam combiner 315 is used to send the modulated optical signal to the optical switch unit 4; The receiving module includes a local oscillator laser 316, a third polarization beam splitter 318 whose input end is connected to the output end of the local oscillator laser 316, a second polarization beam splitter 317, a first 90° mixer 319 whose input end is respectively connected to the first output end of the second polarization beam splitter 317 and the first output end of the third polarization beam splitter 318, a second 90° mixer 3110 whose input end is respectively connected to the second output end of the second polarization beam splitter 317 and the second output end of the third polarization beam splitter 318, a first balanced detector 3111 whose input end is connected to the first output end of the first 90° mixer 319, a second balanced detector 3112 whose input end is connected to the second output end of the first 90° mixer 319, a third balanced detector 3113 whose input end is connected to the first output end of the second 90° mixer 3110, and a A fourth balanced detector 3114 is connected to the second output end of the frequency converter 3110, and an ADC module 3115 whose input end is respectively connected to the output ends of the first balanced detector 3111, the second balanced detector 3112, the third balanced detector 3113 and the fourth balanced detector 3114, and a DSP module 3116 whose input end is connected to the output end of the ADC module 3115; the input end of the second polarization beam splitter 317 is used to receive the optical signal from the optical switch unit 4, the ADC module 3115 and the DSP module 3116 are used to demodulate the signal, the drive control circuit 3117 is used to drive and control the high-speed optical module 31, and at the same time, the original signal sent by the satellite platform data source (such as the perception load) is loaded into the transmitting module, and the signal demodulated by the receiving module is sent to the satellite platform data receiving end (such as the computing load). The actual working process of the high-speed optical module 31 is as follows: the output light of the signal laser 311 is divided into two polarized lights by the first polarization beam splitter 312, and the two polarized lights are modulated by the first IQ modulator 313 and the second IQ modulator 314 respectively, and then combined into one beam by the polarization beam combiner 315 for transmission; the optical signal received by the receiving end and the output light of the local oscillator laser 316 are divided into two polarized lights by the second polarization beam splitter 317 and the third polarization beam splitter 318 respectively, and the two beams of one polarization state are mixed by the first 90° mixer 319 and enter the first balanced detector 3111 and the second balanced detector 3112 respectively, and the two beams of the other polarization state are mixed by the second 90° mixer 3110 and enter the third balanced detector 3113 and the fourth balanced detector 3114 respectively, and the output of each balanced detector is demodulated by the ADC and DSP to obtain the original signal; the drive control circuit 3117 provides drive control for each device. In this embodiment, in order to reduce the manufacturing cost, see Figure 3, the transmitter terminal 514 and the receiver terminal 611 are both transceiver-integrated terminals, which include a transceiver relay optical path 6111 connected to the output end of the power amplifier 513 or the input end of the preamplifier 612, a transceiver antenna 6112 connected to the transceiver relay optical path 6111, a PAT module 6114 electrically connected to the main control unit 1, and a mechanical turntable 6113 electrically connected to the PAT module 6114; the transceiver relay optical path 6111 and the transceiver antenna 6112 are both arranged on the mechanical turntable 6113; The transceiver antenna 6112 is used to transmit optical signals into free space or receive optical signals from free space; the transceiver relay optical path 6111 is used for coupling and conversion between optical fiber signals and free space optical signals, and for beam shaping processing; the PAT module 6114 is used to control the rotation angle of the mechanical turntable 6113, the transceiver direction of the transceiver antenna 6112, and the galvanometer direction of the transceiver relay optical path 6111, so as to realize the capture, tracking and aiming of the transceiver optical signals. In actual application scenarios, the optical switch unit 4 is a MEMS optical switch, a magneto-optical switch, an electro-optical switch or an MZI / MRR-based silicon-based on-chip optical switch. The optical switch unit 4 is provided with a plurality of input ports and output ports to meet the needs of signal transmission. Based on the multi-stage multiplexing in the optical transmitting branch unit 5 and the multi-stage demultiplexing in the optical receiving branch unit 6, the multiplexing and demultiplexing of the optical signal wavelength are realized. Compared with a single wavelength, the system transmission rate is doubled. When two laser communication systems communicate with each other, for one of the systems, the transmitting and receiving optical wavelengths are different. If the transmitting wavelengths are λ1, ..., λ p , then the receiving wavelength is λ'1, ..., λ' p , if the emission wavelength is λ'1, ..., λ' p , then the receiving wavelength is λ1, ..., λ p The transmit and receive wavelengths of the communication system are tunable and can be compatible with both wavelength states of the dual-end system. For the input ends of each multi-stage multiplexing of different wavelengths in the optical transmitting branch unit 5, only one or more ports can be used to achieve multi-level adjustable transmission rate of each transmitting branch; for the output ends of each multi-stage demultiplexing of different wavelengths in the optical receiving branch unit 6, only one or more ports can be used to achieve multi-level adjustable transmission rate of each receiving branch. At the same time, this embodiment also provides a multi-channel transceiver-in-one satellite laser communication method based on an optical switch, which adopts the above-mentioned multi-channel transceiver-in-one satellite laser communication system based on an optical switch, including an optical signal transmitting method, an optical signal receiving method, a communication link transmission bit error rate testing method and a communication system self-testing method; Step a1, the external satellite platform sends an optical signal transmission instruction to the main control unit 1 according to actual needs, and the main control unit 1 controls the high-speed optical transceiver unit 3, the optical switch unit 4 and the optical transmission branch unit 5 according to the optical signal transmission instruction; Step a2: The driving control circuit loads the original signal sent from the satellite platform data source into the multiple high-speed optical modules 31 in the high-speed optical transceiver unit 3 to generate a modulated optical signal, and the modulated optical signal is transmitted to the optical switch unit 4 through the corresponding input port; Step a3, the optical switch unit 4 distributes the modulated optical signal to the corresponding optical transmission branch 51 in the optical transmission branch unit 5 through the corresponding output port; Step a4, the optical transmission branch 51 multiplexes, amplifies and transmits the multiple modulated optical signals into free space to complete the optical signal transmission; The optical signal receiving method comprises the following steps: Step b1, the external satellite platform sends an optical signal receiving instruction to the main control unit 1 according to actual needs, and the main control unit 1 controls the high-speed optical transceiver unit 3, the optical switch unit 4 and the optical receiving branch unit 6 according to the optical signal transmitting instruction; Step b2: the optical receiving branch 61 amplifies the optical signal received in the free space, demultiplexes it and transmits it to the optical switch unit 4; Step b3, the optical switch unit 4 distributes the demultiplexed optical signal to the corresponding high-speed optical module 31 in the high-speed optical transceiver unit 3 through the corresponding output port; Step b4: The high-speed optical module 31 demodulates the optical signal and transmits it to the satellite platform data receiving end to complete the optical signal reception. The communication link transmission bit error rate test method comprises the following steps: Step c1, the external satellite platform sends a communication link transmission bit error rate test instruction to the main control unit 1 of the laser communication system A and the laser communication system B according to actual needs, and the main control unit 1 of the laser communication system A controls the high-speed optical transceiver unit 3, the optical switch unit 4 and the optical transmission branch unit 5 according to the communication link transmission bit error rate test instruction; Step c2, the FPGA in the driving control circuit 3117 in the laser communication system A generates a pseudo-random binary sequence, which is sent to the laser communication system B via the high-speed optical transceiver unit 3, the optical switch unit 4, and the optical transmission branch unit 5; Step c3, after the laser communication system B receives the optical signal, it passes through its optical receiving branch unit 6 and optical switch unit 4 to the high-speed optical transceiver unit 3, and the driving control circuit 3117 deframes, synchronizes and compares the signal, and then counts the communication link transmission bit error rate. The communication system self-test method comprises the following steps: Step d1, the external satellite platform sends an optical signal transmission instruction to the main control unit 1 according to actual needs, and the main control unit 1 controls the high-speed optical transceiver unit 3, the optical switch unit 4 and the optical transmission branch unit 5 according to the optical signal transmission instruction; Step d2, turning off the power amplifier 513 and the preamplifier 612; Step d3, configuring the connection relationship between the optical switch input and output ports, configuring the input end of the optical switch unit 4 corresponding to the second output end of the transmitting end coupler 512 to the output end of the optical switch unit 4 corresponding to the second input end of the receiving end coupler 613; Step d4, the FPGA in the drive control circuit 3117 self-generates a pseudo-random binary sequence, which passes through the high-speed optical transceiver unit 3, the optical switch unit 4, the multi-stage multiplexing module 511 and the transmitting end coupler 512 in the optical transmitting branch unit 5, the optical switch unit 4, the receiving end coupler 613 and the multi-stage demultiplexing module 614 in the optical receiving branch unit 6, and the optical switch unit 4 back to the high-speed optical transceiver unit 3. After the drive control circuit 3117 deframes, synchronizes, and compares the signal, the self-test line bit error rate is calculated. The multiplexing methods described in this article are all wavelength division multiplexing. Table 1 below is a comparison table of the English abbreviations, English full names and Chinese meanings in this article. Table 1 Comparison table of English abbreviations, English full names and Chinese meanings in this article Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. For ordinary professional and technical personnel in the field, the specific technical solutions recorded in the aforementioned embodiments can be modified, or some of the technical features therein can be replaced by equivalents, and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions protected by the present invention.

Claims

1. A multi-channel transceiver satellite laser communication system based on optical switches, characterized in that: The invention comprises a main control unit (1) and a power supply unit (2) which are electrically connected to an external satellite platform respectively, and a high-speed optical transceiver unit (3), an optical switch unit (4), an optical transmission branch unit (5) and an optical reception branch unit (6) which are connected to the main control unit (1) and the power supply unit (2) respectively; the main control unit (1) and the power supply unit (2) are connected to each other; The high-speed optical transceiver unit (3) is used to generate and modulate multiple high-speed optical signals according to the transmission instruction of the main control unit (1), and / or demodulate the received optical signals and send them to the main control unit (1), and includes m high-speed optical modules (31) capable of transmitting and receiving optical signals, m>1, m is an integer, and each high-speed optical module (31) is respectively connected to the corresponding input end and output end of the optical switch unit (4); The optical transmission branch unit (5) comprises n optical transmission branches (51), n>1, n is an integer, the input end of each optical transmission branch (51) is connected to the corresponding output end of the optical switch unit (4), the first output end is used to send optical signals, and the second output end is connected to the corresponding input end of the optical switch unit (4); each optical transmission branch (51) is used to multiplex, amplify and transmit 2p optical signals generated after modulation by the high-speed optical module (31) in the high-speed optical transceiver unit (3) into free space, p>1, p is an integer; The optical receiving branch unit (6) comprises n optical receiving branches (61), wherein a first input end of each optical receiving branch (61) is used to receive an external optical signal, a second input end is connected to a corresponding output end of the optical switch unit (4), and an output end is connected to a corresponding input end of the optical switch unit (4); each optical receiving branch (61) is used to perform low-noise amplification on a weak optical signal received in free space, and then demultiplex to generate 2p optical signals and transmit them to a high-speed optical transceiver unit (3) through the optical switch unit (4) for demodulation; The number of input ports of the optical switch unit (4) is defined as S in , the number of output ports is S out , then S in ≥m+n+2pn,S out ≥m+n+2pn; The main control unit (1) is used to control the high-speed optical transceiver unit (3), the optical switch unit (4), the optical transmission branch unit (5) and the optical reception branch unit (6) to receive or send signals according to a task instruction issued by a satellite platform; and the power supply unit (2) is used to supply power to the main control unit (1), the high-speed optical transceiver unit (3), the optical switch unit (4), the optical transmission branch unit (5) and the optical reception branch unit (6) using the electric energy provided by the satellite platform.

2. According to claim 1, a multi-channel transceiver satellite laser communication system based on optical switches is characterized in that: Each of the optical transmission branches (51) comprises a multi-stage multiplexing module (511) whose input end is connected to an output end corresponding to an optical switch unit (4), a transmitting end coupler (512) whose input end is connected to an output end of the multi-stage multiplexing module (511), a power amplifier (513) whose input end is connected to a first output end of the transmitting end coupler (512), and a transmitting end machine (514) whose input end is connected to an output end of the power amplifier (513); a second output end of the transmitting end coupler (512) is connected to a corresponding input end of the optical switch unit (4); The multi-stage multiplexing module (511) is used to wavelength-division multiplex 2p optical signals into one communication line; the power amplifier (513) is used to perform high-power amplification on the optical signal; the transmitting end coupler (512) is used to implement communication link self-test; and the transmitting end machine (514) is used to transmit the optical signal into free space.

3. According to claim 1, a multi-channel transceiver satellite laser communication system based on optical switches is characterized in that: Each of the optical receiving branches (61) comprises a receiving end (611), a preamplifier (612) whose input end is connected to the output end of the receiving end (611), a receiving end coupler (613) whose first input end is connected to the output end of the preamplifier (612), and a multi-stage demultiplexing module (614) whose input end is connected to the receiving end coupler (613); a second input end of the receiving end coupler (613) is connected to a corresponding output end of the optical switch unit (4); The receiving end machine (611) is used to receive optical signals from free space; the preamplifier (612) is used to perform low-noise amplification on weak signals in the received optical signals; the receiving end coupler (613) is used to implement self-test of the communication link; and the multi-stage demultiplexing module (614) is used to implement separate filtering of signals of different wavelengths.

4. According to claim 3, a multi-channel transceiver satellite laser communication system based on optical switches is characterized in that: The optical switch unit (4) and each high-speed optical module (31), the optical switch unit (4) and each multi-stage multiplexing module (511), the optical switch unit (4) and each multi-stage demultiplexing module (611), the multi-stage multiplexing module (511), the transmitting end coupler (512), the power amplifier (513) and the transmitting end machine (514) in each optical transmitting branch (51), and the receiving end machine (611), the preamplifier (612), the receiving end coupler (613) and the multi-stage demultiplexing module (614) in each optical receiving branch (61) are all connected via optical fibers.

5. According to claim 4, a multi-channel transceiver satellite laser communication system based on optical switches is characterized in that: The modulation mode adopted by the high-speed optical module (31) is OOK, BPSK, QPSK, DP-QPSK, 8-QAM or 16-QAM.

6. According to claim 4, a multi-channel transceiver satellite laser communication system based on optical switches is characterized in that: The modulation mode of the high-speed optical module (31) is DP-QPSK, and comprises a transmitting module, a receiving module, and a driving control circuit (3117) electrically connected to the transmitting module, the receiving module, the main control unit (1) and the power supply unit (2); The transmitting module comprises a signal laser (311), a first polarization beam splitter (312) whose input end is connected to the output end of the signal laser (311), a first IQ modulator (313) whose input end is connected to the first output end of the first polarization beam splitter (312), a second IQ modulator (314) whose input end is connected to the second output end of the first polarization beam splitter (312), and a polarization beam combiner (315) whose input end is respectively connected to the output end of the first IQ modulator (313) and the output end of the second IQ modulator (314); the signal laser (311) is used to transmit an optical signal of a preset wavelength according to a transmitting instruction of the main control unit (1); the first IQ modulator (313) and the second IQ modulator (314) are used to modulate the optical signal; and the output end of the polarization beam combiner (315) is used to send the modulated optical signal to the optical switch unit (4); The receiving module comprises a local oscillator laser (316), a third polarization beam splitter (318) whose input end is connected to the output end of the local oscillator laser (316), a second polarization beam splitter (317), a first 90° mixer (319) whose input end is respectively connected to the first output end of the second polarization beam splitter (317) and the first output end of the third polarization beam splitter (318), a second 90° mixer (3110) whose input end is respectively connected to the second output end of the second polarization beam splitter (317) and the second output end of the third polarization beam splitter (318), a first balanced detector (3111) whose input end is connected to the first output end of the first 90° mixer (319), a second balanced detector (3112) whose input end is connected to the second output end of the first 90° mixer (319), a third balanced detector (3113) whose input end is connected to the first output end of the second 90° mixer (3110), and a A fourth balanced detector (3114) connected to the second output end of the second 90° mixer (3110), an ADC module (3115) whose input end is respectively connected to the output ends of the first balanced detector (3111), the second balanced detector (3112), the third balanced detector (3113) and the fourth balanced detector (3114), and a DSP module (3116) whose input end is connected to the output end of the ADC module (3115); the input end of the second polarization beam splitter (317) is used to receive an optical signal from an optical switch unit (4); the ADC module (3115) and the DSP module (3116) are used to demodulate the signal; the drive control circuit (3117) is used to drive and control the high-speed optical module (31), and at the same time, load the original signal sent from the satellite platform data source into the transmitting module, and send the signal demodulated by the receiving module to the satellite platform data receiving end.

7. According to claim 6, a multi-channel transceiver satellite laser communication system based on optical switches is characterized in that: The transmitting terminal (514) and the receiving terminal (611) are both transceiver-integrated terminals, and the transceiver-integrated terminals include a transceiver relay optical path (6111) connected to the output end of the power amplifier (513) or the input end of the preamplifier (612), a transceiver antenna (6112) connected to the transceiver relay optical path (6111), a PAT module (6114) electrically connected to the main control unit (1), and a mechanical turntable (6113) electrically connected to the PAT module (6114); the transceiver relay optical path (6111) and the transceiver antenna (6112) are both arranged on the mechanical turntable (6113); The transceiver antenna (6112) is used to transmit optical signals into free space or receive optical signals from free space; the transceiver relay optical path (6111) is used to couple and convert optical fiber signals with free space optical signals and perform beam shaping processing; the PAT module (6114) is used to control the rotation angle of the mechanical turntable (6113), the transceiver direction of the transceiver antenna (6112) and the galvanometer direction of the transceiver relay optical path (6111), so as to achieve the capture, tracking and aiming of the transceiver optical signals.

8. The multi-channel transceiver satellite laser communication system based on optical switch according to claim 7 is characterized in that: The optical switch unit (4) is a MEMS optical switch, a magneto-optical switch, an electro-optical switch or an MZI / MRR-based silicon-based on-chip optical switch.

9. A multi-channel transceiver satellite laser communication method based on optical switches, characterized in that: A multi-channel transceiver satellite laser communication system based on an optical switch as described in any one of claims 1 to 8, comprising an optical signal transmitting method and an optical signal receiving method; The optical signal transmission method comprises the following steps: Step a1: the external satellite platform sends an optical signal transmission instruction to the main control unit (1) according to actual needs, and the main control unit (1) controls the high-speed optical transceiver unit (3), the optical switch unit (4) and the optical transmission branch unit (5) according to the optical signal transmission instruction; Step a2: the driving control circuit loads the original signal sent from the satellite platform data source into the multiple high-speed optical modules (31) in the high-speed optical transceiver unit (3), generates a modulated optical signal, and transmits the modulated optical signal to the optical switch unit (4) through the corresponding input port; Step a3, the optical switch unit (4) distributes the modulated optical signal to the corresponding optical transmission branch (51) in the optical transmission branch unit (5) through the corresponding output port; Step a4, the optical transmission branch (51) multiplexes, amplifies and transmits the multiple modulated optical signals into free space to complete the optical signal transmission; The optical signal receiving method comprises the following steps: Step b1, the external satellite platform sends an optical signal receiving instruction to the main control unit (1) according to actual needs, and the main control unit (1) controls the high-speed optical transceiver unit (3), the optical switch unit (4) and the optical receiving branch unit (6) according to the optical signal transmitting instruction; Step b2, the optical receiving branch (61) amplifies the optical signal received in the free space, then demultiplexes it and transmits it to the optical switch unit (4); Step b3, the optical switch unit (4) distributes the demultiplexed optical signal to the corresponding high-speed optical module (31) in the high-speed optical transceiver unit (3) through the corresponding output port; Step b4: The high-speed optical module (31) demodulates the optical signal and transmits it to the satellite platform data receiving end, thereby completing the optical signal reception.

10. The method for satellite laser communication with multi-channel transceiver integration based on optical switch according to claim 9, characterized in that: It also includes a communication link transmission bit error rate test method and a communication system self-test method; The communication link transmission bit error rate testing method comprises the following steps: Step c1, the external satellite platform sends a communication link transmission bit error rate test instruction to the main control unit (1) of the laser communication system A and the laser communication system B according to actual needs, and the main control unit (1) of the laser communication system A controls the high-speed optical transceiver unit (3), the optical switch unit (4) and the optical transmission branch unit (5) according to the communication link transmission bit error rate test instruction; Step c2, the FPGA in the driving control circuit (3117) in the laser communication system A generates a pseudo-random binary sequence, and sends it to the laser communication system B via the high-speed optical transceiver unit (3), the optical switch unit (4), and the optical transmission branch unit (5); Step c3, after the laser communication system B receives the optical signal, it passes through its optical receiving branch unit (6), optical switch unit (4) to the high-speed optical transceiver unit (3), and the driving control circuit (3117) deframes, synchronizes and compares the signal, and then calculates the communication link transmission bit error rate. The communication system self-test method comprises the following steps: Step d1, the external satellite platform sends an optical signal transmission instruction to the main control unit (1) according to actual needs, and the main control unit (1) controls the high-speed optical transceiver unit (3), the optical switch unit (4) and the optical transmission branch unit (5) according to the optical signal transmission instruction; Step d2, turning off the power amplifier (513) and the preamplifier (612); Step d3, configuring the connection relationship between the input and output ports of the optical switch, configuring the input end of the optical switch unit (4) corresponding to the second output end of the transmitting end coupler (512) to the output end of the optical switch unit (4) corresponding to the second input end of the receiving end coupler (613); Step d4, the FPGA in the drive control circuit (3117) generates a pseudo-random binary sequence, which is then sent back to the high-speed optical transceiver unit (3), the optical switch unit (4), the multi-stage multiplexing module (511) and the transmitting end coupler (512) in the optical transmitting branch unit (5), the optical switch unit (4), the receiving end coupler (613) and the multi-stage demultiplexing module (614) in the optical receiving branch unit (6), and the optical switch unit (4). The drive control circuit (3117) performs deframing, synchronization, and comparison on the signal, and then calculates the bit error rate of the self-test line.

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