A multi-channel transceiving integrated satellite laser communication system and method based on optical switches

Abstract

The application relates to an optical-electric communication system, in particular to a multi-channel transceiving integrated satellite laser communication system and method based on an optical switch, aiming to solve the problems that the existing communication system has low integration, cannot realize the functions of signal transceiving integration, signal wavelength multiplexing and demultiplexing, and is prone to cause the problems of large volume of the satellite communication system and difficulty in realizing super-high-speed signal transmission. The application comprises a master control unit and a power supply unit electrically connected with an external satellite platform, and a high-speed optical transceiving unit, an optical switch unit, an optical transmitting branch unit and an optical receiving branch unit connected with the master control unit and the power supply unit respectively; the high-speed optical transceiving unit comprises m high-speed optical modules capable of performing optical signal transceiving; the optical transmitting branch unit comprises n optical transmitting branches; and the optical receiving branch unit comprises n optical receiving branches. The application has high integration, does not need multiple optical-electric conversions, and has high link reliability of the communication system.

Description

TECHNICAL FIELD

[0001] The present application relates to an optoelectronic communication system, in particular to a multi-channel transceiver integrated satellite laser communication system and method based on optical switches. BACKGROUND

[0002] In the past few decades, microwave communication is the main way of inter-satellite / earth-satellite information interaction, which transmits information through electromagnetic waves in the microwave frequency band (usually between 300 MHz and 300 GHz). 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 devices (such as high-definition image shooting systems, high-precision sensors, and spectral analyzers), the amount of data that needs to be transmitted between inter-satellite / earth-satellite has increased explosively. Currently, satellites generate several hundred GB (gigabytes) or even several TB (terabytes) of data per day, so the bandwidth and capacity of space information networks in the field are required to be higher.

[0003] Limited by carrier spectrum resources, the transmission rate of a single channel of microwave communication is usually in the order of hundreds of Mbps (megabits per second), which cannot meet the current massive satellite data transmission requirements. Laser communication uses laser beams as the carrier of information transmission, and transmits information by modulating the wavelength, frequency, phase or intensity of the laser. Its frequency can reach THz (terahertz) level, and can achieve extremely high transmission rate (such as 10 Gbps, 100 Gbps). Using wavelength division multiplexing technology can further improve the transmission rate. Due to its large bandwidth, high speed, low delay, good security, strong anti-interference ability, small size, and light weight, laser communication is currently in a rapid development stage, and has great potential in deep space communication and satellite communication fields.

[0004] Currently, satellite laser communication networks are being built, but there are mainly the following problems:

[0005] [1] For multiple laser communication system terminals on each satellite, in order to improve reliability, multiple backups of core devices (such as high-speed optical modules with high cost) are often needed, resulting in repeated use of core devices and waste of resources;

[0006] [2] The rate of spaceborne laser communication in space information networks is still mainly 5 Gbps and 10 Gbps, and super-high-speed transmission such as 100 Gbps is still in the experimental stage;

[0007] [3] The communication system and the switching system are separate, and there is a problem of high power consumption caused by multiple optoelectronic conversions, and the system is large in size, low in integration, and low in utilization of on-board resources.

[0008] The Chinese patent CN114024798A discloses a spaceborne microwave-optical hybrid communication and switching integrated system and method, but the prior art has the problems that the integration degree of the system is not high enough, and the functions of signal transceiving integration, signal wavelength multiplexing and demultiplexing cannot be realized, which easily leads to a large size of the satellite communication system and difficulty in realizing super-high-speed signal transmission. SUMMARY

[0009] The purpose of the present application is to solve the problems of the prior art that the integration degree of the communication system is not high enough, and the functions of signal transceiving integration and signal wavelength multiplexing and demultiplexing cannot be realized, which easily leads to a large size of the satellite communication system and difficulty in realizing super-high-speed signal transmission, and to provide a multi-channel transceiving integrated satellite laser communication system based on an optical switch.

[0010] To achieve the above-mentioned purpose, the technical solution provided by the present application is as follows:

[0011] A multi-channel transceiving integrated satellite laser communication system based on an optical switch, characterized in that:

[0012] The system comprises a master control unit and a power supply unit which are electrically connected to an external satellite platform, and a high-speed optical transceiving unit, an optical switch unit, an optical transmission branch unit and an optical receiving branch unit which are connected to the master control unit and the power supply unit, respectively; the master control unit and the power supply unit are connected to each other;

[0013] The high-speed optical transceiving unit is used for generating and modulating multi-channel high-speed optical signals according to the transmission instruction of the master control unit, and / or demodulating and sending the received optical signals to the master control unit, and comprises m high-speed optical modules which can perform optical signal transceiving, m>1, m being an integer, each high-speed optical module being connected to the corresponding input end and output end of the optical switch unit;

[0014] The optical transmission branch unit comprises n optical transmission branches, n>1, n being an integer, the input end of each optical transmission branch being connected to the corresponding output end of the optical switch unit, the first output end of each optical transmission branch being used for transmitting optical signals, and the second output end of each optical transmission branch being connected to the corresponding input end of the optical switch unit; each optical transmission branch is used for multiplexing, amplifying and transmitting 2p optical signals generated by the high-speed optical modules of the high-speed optical transceiving unit after modulation into the free space, p>1, p being an integer;

[0015] The optical receiving branch unit comprises n optical receiving branches, the first input end of each optical receiving branch being used for receiving external optical signals, the second input end of each optical receiving branch being connected to the corresponding output end of the optical switch unit, and the output end of each optical receiving branch being connected to the corresponding input end of the optical switch unit; each optical receiving branch is used for low-noise amplifying the weak optical signals received in the free space, then demultiplexing 2p optical signals and transmitting the 2p optical signals to the high-speed optical transceiving unit through the optical switch unit for demodulation;

[0016] The number of input ports of the optical switch unit is defined as S in , and the number of output ports is S out , then S in ≥m+n+2pn, S out ≥m+n+2pn;

[0017] The master 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 transmit signals according to the task instructions issued by the satellite platform; the power supply unit is used to supply power to the master control unit, the high-speed optical transceiver unit, the optical switch unit, the optical transmitting branch unit and the optical receiving branch unit by using the power provided by the satellite platform.

[0018] Further, each of the optical transmitting branches comprises a multi-stage multiplexing module, a transmitting end coupler, a power amplifier and a transmitting end machine, wherein the input end of the multi-stage multiplexing module is connected to the output end of the optical switch unit, the input end of the transmitting end coupler is connected to the output end of the multi-stage multiplexing module, the input end of the power amplifier is connected to the first output end of the transmitting end coupler, and the input end of the transmitting end machine is connected to the output end of the power amplifier; the second output end of the transmitting end coupler is connected to the corresponding input end of the optical switch unit.

[0019] The multi-stage multiplexing module is used to wavelength division multiplex 2p optical signals into one communication line; the power amplifier is used to amplify the optical signals with high power; the transmitting end coupler is used to realize communication link self-test; and the transmitting end machine is used to transmit the optical signals to the free space.

[0020] Further, each of the optical receiving branches comprises a receiving end machine, a preamplifier, a receiving end coupler and a multi-stage demultiplexing module, wherein the input end of the receiving end machine is connected to the output end of the preamplifier, the first input end of the preamplifier is connected to the output end of the receiving end coupler, and the input end of the multi-stage demultiplexing module 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.

[0021] The receiving end machine is used to receive the optical signals from the free space; the preamplifier is used to amplify the weak signals in the received optical signals with low noise; the receiving end coupler is used to realize communication link self-test; and the multi-stage demultiplexing module is used to realize the filtering of different wavelength signals.

[0022] Further, the optical switch unit, each multi-stage multiplexing module, each multi-stage demultiplexing module, the multi-stage multiplexing module, the transmitting end coupler, the power amplifier and the transmitting end machine in each of the optical transmitting branches, and the receiving end machine, the preamplifier, the receiving end coupler and the multi-stage demultiplexing module in each of the optical receiving branches are connected through optical fibers.

[0023] Further, the modulation mode of the high-speed optical module is OOK, BPSK, QPSK, DP-QPSK, 8-QAM or 16-QAM.

[0024] Further, the modulation mode of the high-speed optical module is DP-QPSK, which comprises a transmitting module, a receiving module, and a driving control circuit electrically connected with the transmitting module, the receiving module, a master control unit and a power supply unit.

[0025] The transmitting module comprises a signal laser, a first polarization beam splitter with an input end connected with an output end of the signal laser, a first IQ modulator with an input end connected with a first output end of the first polarization beam splitter, a second IQ modulator with an input end connected with a second output end of the first polarization beam splitter, and a polarization combiner with input ends connected with output ends of the first IQ modulator and the second IQ modulator, respectively; the signal laser is configured to transmit an optical signal of a preset wavelength according to a transmitting instruction of the master control unit, the first IQ modulator and the second IQ modulator are configured to modulate the optical signal, and an output end of the polarization combiner is configured to send the modulated optical signal to an optical switch unit.

[0026] The receiving module comprises a local laser, a third polarization beam splitter with an input end connected with an output end of the local laser, a second polarization beam splitter, a first 90° mixer with input ends connected with a first output end of the second polarization beam splitter and a first output end of the third polarization beam splitter, respectively, a second 90° mixer with input ends connected with a second output end of the second polarization beam splitter and a second output end of the third polarization beam splitter, respectively, a first balanced detector with an input end connected with a first output end of the first 90° mixer, a second balanced detector with an input end connected with a second output end of the first 90° mixer, a third balanced detector with an input end connected with a first output end of the second 90° mixer, a fourth balanced detector with an input end connected with a second output end of the second 90° mixer, an ADC module with input ends connected with output ends of the first balanced detector, the second balanced detector, the third balanced detector and the fourth balanced detector, and a DSP module with an input end connected with an output end of the ADC module; the input end of the second polarization beam splitter is configured to receive the optical signal from the optical switch unit, the ADC module and the DSP module are configured to demodulate and process the signal, and the driving control circuit is configured to drive and control the high-speed optical module, load original signals from a satellite platform data source to the transmitting module, and send the demodulated signals of the receiving module to a satellite platform data receiving end.

[0027] Further, the transmitting terminal and the receiving terminal are both transceiving integrated terminals, the transceiving integrated terminal comprises a transceiving relay optical path connected with an output end of a power amplifier or an input end of a preamplifier, a transceiving antenna connected with the transceiving relay optical path, a PAT module electrically connected with a master control unit, and a mechanical turntable electrically connected with the PAT module; the transceiving relay optical path and the transceiving antenna are both arranged on the mechanical turntable;

[0028] The transceiving antenna is used for transmitting or receiving optical signals into free space; the transceiving relay optical path is used for coupling conversion between fiber signals and free space optical signals, and performs beam shaping processing; the PAT module is used for controlling the rotation angle of the mechanical turntable, the transceiving direction of the transceiving antenna and the galvanometer direction of the transceiving relay optical path, so as to realize the capture, tracking and aiming of the transceiving optical signals.

[0029] Further, the optical switch unit is a MEMS optical switch, a magneto-optical switch, an electro-optical switch or a silicon-based optical switch based on MZI / MRR.

[0030] Meanwhile, the application also provides a multi-channel transceiving integrated satellite laser communication method based on an optical switch, which is characterized in that the method adopts the multi-channel transceiving integrated satellite laser communication system based on an optical switch, and comprises an optical signal transmitting method and an optical signal receiving method.

[0031] The optical signal transmitting method comprises the following steps:

[0032] Step a1, an external satellite platform sends an optical signal transmitting instruction to the master control unit according to actual requirements, and the master control unit controls the high-speed optical transceiving unit, the optical switch unit and the optical transmitting branch unit according to the optical signal transmitting instruction;

[0033] Step a2, the driving control circuit loads the original signal from the satellite platform data source to the multiple high-speed optical modules in the high-speed optical transceiving unit, generates a modulated optical signal, and transmits the modulated optical signal to the optical switch unit through the corresponding input port;

[0034] Step a3, the optical switch unit distributes the modulated optical signal to the corresponding optical transmitting branch in the optical transmitting branch unit through the corresponding output port;

[0035] Step a4, the optical transmitting branch multiplexes, amplifies and transmits the multiple modulated optical signals to the free space, and completes the optical signal transmission;

[0036] The optical signal receiving method comprises the following steps:

[0037] 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 receiving instruction;

[0038] Step b2, the optical receiving branch amplifies the received optical signal in free space, then demultiplexes and transmits it to the optical switch unit;

[0039] 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;

[0040] Step b4, the high-speed optical module transmits the demodulated optical signal to the satellite platform data receiving end, completing the optical signal receiving.

[0041] Further, a multi-channel transceiving 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;

[0042] The communication link transmission bit error rate test method includes the following steps:

[0043] 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 transmitting branch unit according to the communication link transmission bit error rate test instruction;

[0044] Step c2, the FPGA in the drive control circuit in the laser communication system A generates a pseudo-random binary sequence, which is sent to the laser communication system B through the high-speed optical transceiver unit, the optical switch unit and the optical transmitting branch unit;

[0045] Step c3, after the laser communication system B receives the optical signal, the optical receiving branch unit, the optical switch unit and the high-speed optical transceiver unit of the laser communication system B, the drive control circuit demultiplexes, synchronizes and compares the signal, and then calculates the communication link transmission bit error rate;

[0046] The communication system self-test method includes the following steps:

[0047] Step d1, the external satellite platform sends an optical signal transmitting 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 transmitting branch unit according to the optical signal transmitting instruction;

[0048] Step d2, turn off the power amplifier and the preamplifier;

[0049] Step d3, configure the optical switch input, output port connection relationship, the second output end of the transmitting end coupler is configured to the optical switch unit input end corresponding to the second input end of the receiving end coupler to the optical switch unit output end;

[0050] Step d4, the FPGA in the driving control circuit generates a pseudo-random binary sequence, returns to the high-speed optical transceiver unit through the multi-stage multiplexing module in the optical transmitting branch unit, the optical switch unit, the optical receiving branch unit, the receiving end coupler and the multi-stage demultiplexing module in the optical switch unit, and the driving control circuit after the signal is deframed, synchronized and compared, the bit error rate of the self-test line is counted.

[0051] Compared with the prior art, the beneficial effects of the present application are:

[0052] 1. The multi-channel transceiving integrated satellite laser communication system based on an optical switch provided by the present application is provided with an optical switch unit, has high integration, and does not need multiple photoelectric conversions, so that the weight and volume of the satellite communication system can be reduced, the optical switch unit is provided with multiple input end ports and output end ports, and meets the demand of signal transmission; multiple high-speed optical modules are provided, each high-speed optical module can realize the functions of optical signal transmission and reception, and the link reliability of the communication system is high.

[0053] 2. The multi-channel transceiving integrated satellite laser communication system based on an optical switch provided by the present application is provided with multi-stage multiplexing modules and multi-stage demultiplexing modules, and realizes the multi-wavelength multiplexing function of the communication system.

[0054] 3. The multi-channel transceiving integrated satellite laser communication system based on an optical switch provided by the present application, the transmitting end machine and the receiving end machine are transceiving integrated end machines, which reduces the manufacturing difficulty of the communication system and has high flexibility.

[0055] 4. The multi-channel transceiving integrated satellite laser communication method based on an optical switch provided by the present application can simultaneously meet the demand of different links, different rates, even high-rate (such as 100Gbps, 200Gbps, 400Gbps) service transmission and distribution, and the transmission rate is increased by several times compared with the existing single-wavelength transmission method. BRIEF DESCRIPTION OF DRAWINGS

[0056] Figure 1 It is a schematic diagram of the multi-channel transceiving integrated satellite laser communication system based on an optical switch of the present application;

[0057] Figure 2 It is a schematic diagram of the high-speed optical module in the multi-channel transceiving integrated satellite laser communication system based on an optical switch of the present application;

[0058] Figure 3The schematic diagram of the transceiving integrated terminal machine in the multi-channel transceiving integrated satellite laser communication system based on the optical switch according to the embodiment of the present application;

[0059] Marked with the following reference numerals:

[0060] 1 - master 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, 3115 - ADC module, 3116 - DSP module, 3117 - drive control circuit; 4 - optical switch unit; 5 - optical transmission branch unit, 51 - optical transmission branch, 511 - multi-stage multiplexing module, 512 - transmission end coupler, 513 - power amplifier, 514 - transmission end machine; 6 - optical receiving branch unit, 611 - receiving end machine, 6111 - transceiving relay optical path, 6112 - transceiving 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

[0061] The present application will be further described below in conjunction with the drawings and specific embodiments.

[0062] A multi-channel transceiving integrated satellite laser communication system based on an optical switch, the schematic diagram of which is shown in Figure 1 ;

[0063] It comprises a master control unit 1 and a power supply unit 2 respectively electrically connected with an external satellite platform, and a high-speed optical transceiver unit 3, an optical switch unit 4, an optical transmission branch unit 5 and an optical receiving branch unit 6 respectively connected with the master control unit 1 and the power supply unit 2; the master control unit 1 and the power supply unit 2 are connected with each other;

[0064] 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 master unit 1, and / or demodulate and send the received optical signals to the master unit 1, and includes six high-speed optical modules 31 capable of optical signal transceiving, each of which is connected with the corresponding input end and output end of the optical switch unit 4; in actual application scenarios, the high-speed optical modules 31 can be increased to realize backup, for example, one newly added backup high-speed optical module 31 is in a non-working state under normal circumstances, and can simultaneously take over the backup and replacement work of three (the number of high-speed optical modules 31 taken over can also be adjusted in actual use) working high-speed optical modules 31, when any one or more working high-speed optical modules 31 fails, the master unit 1 can detect it in time and transfer its original signal transmission task to the backup high-speed optical module 31, thereby ensuring the correct transmission of optical signals; when all the high-speed optical modules 31 as backup are used up, if the existing working high-speed optical module 31 is damaged, the master unit 1 will transfer its original signal transmission task to another working high-speed optical module 31, and the high-speed optical module 31 transferred with the task will execute its own task first, and then execute the transferred task, which may prolong the completion time of the signal transmission task, but will not cause the interruption of a certain communication branch, thereby ensuring that each signal can be correctly transmitted or received, greatly improving the link reliability of the communication system.

[0065] The optical transmission branch unit 5 includes three optical transmission branches 51, the input end of each optical transmission branch 51 is connected with 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 with the corresponding input end of the optical switch unit 4; each optical transmission branch 51 is used to multiplex, amplify and transmit four optical signals generated after the high-speed optical modules 31 in the high-speed optical transceiver unit 3 are modulated to the free space;

[0066] The optical receiving branch unit 6 includes three optical receiving branches 61, the first input end of each optical receiving branch 61 is used to receive external optical signals, the second input end is connected with the corresponding output end of the optical switch unit 4, and the output end is connected with the corresponding input end of the optical switch unit 4; each optical receiving branch 61 is used to amplify the weak optical signals received in the free space with low noise, then demultiplex four optical signals and transmit them to the high-speed optical transceiver unit 3 through the optical switch unit 4 for demodulation;

[0067] The number of input ports of the optical switch unit 4 is defined as S in , the number of output ports is S out , S in ≥21, S out ≥21;

[0068] The main control unit 1 is used for controlling the high-speed optical transceiver unit 3, the optical switch unit 4, the optical transmitting branch unit 5 and the optical receiving branch unit 6 to receive or transmit signals according to the task instruction issued by the satellite platform; the power supply unit 2 is used for supplying power to the main control unit 1, the high-speed optical transceiver unit 3, the optical switch unit 4, the optical transmitting branch unit 5 and the optical receiving branch unit 6 by using the power provided by the satellite platform.

[0069] The optical transmitting branch unit 5 includes three optical transmitting branches 51, each of which includes a multi-stage multiplexing module 511, whose input end is connected with the corresponding output end of the optical switch unit 4, a transmitting end coupler 512, whose input end is connected with the output end of the multi-stage multiplexing module 511, a power amplifier 513, whose input end is connected with the first output end of the transmitting end coupler 512, and a transmitting end machine 514, whose input end is connected with the output end of the power amplifier 513; the second output end of the transmitting end coupler 512 is connected with the corresponding input end of the optical switch unit 4.

[0070] The multi-stage multiplexing module 511 is used for wavelength division multiplexing 2p optical signals into one communication line; the power amplifier 513 is used for high-power amplification of the optical signal; the transmitting end coupler 512 is used for realizing communication link self-test; and the transmitting end machine 514 is used for transmitting the optical signal to the free space, and the actual free space is the atmospheric environment or vacuum environment 7.

[0071] The optical receiving branch unit 6 includes three optical receiving branches 61, each of which includes a receiving end machine 611, a preamplifier 612, whose input end is connected with the output end of the receiving end machine 611, a receiving end coupler 613, whose first input end is connected with the output end of the preamplifier 612, and a multi-stage demultiplexing module 614, whose input end is connected with the receiving end coupler 613; the second input end of the receiving end coupler 613 is connected with the output end of the optical switch unit 4.

[0072] The receiving end machine 611 is used for receiving the optical signal from the free space; the preamplifier 612 is used for low-noise amplification of the weak signal in the received optical signal; the multi-stage demultiplexing module 614 is used for realizing separate filtering of different wavelength signals; and the receiving end coupler 613 is used for realizing communication link self-test.

[0073] The signal flow when the communication system is self-tested 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, the optical switch unit 4 transmits the optical signal to the receiving end coupler 613 through the second input end, then the optical signal enters the multi-stage demultiplexing module 614 through the receiving end coupler 613, and finally the optical signal is transmitted to the corresponding high-speed optical module 31 through the multi-stage demultiplexing module 614, which realizes the in-orbit self-test of the system.

[0074] The main control unit 1 is used for controlling the power supply unit 2, the high-speed optical transceiver unit 3, the optical switch unit 4, the optical transmitting branch unit 5 and the optical receiving branch unit 6 to receive or send signals according to the task instruction issued by the satellite platform; the power supply unit 2 is used for supplying power to the high-speed optical transceiver unit 3, the optical switch unit 4, the optical transmitting branch unit 5 and the optical receiving branch unit 6 by using the power provided by the satellite platform; and the high-speed optical transceiver unit 3 is used for modulating and demodulating multiple high-speed optical signals.

[0075] 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 614, and each 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 connected through optical fibers.

[0076] In actual application scenarios, the modulation mode of 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, which is shown in Figure 2 The modulation mode of the high-speed optical module 31 is DP-QPSK, which includes a transmitting module, a receiving module, and a driving control circuit 3117 electrically connected with the transmitting module, the receiving module, the main control unit 1 and the power supply unit 2.

[0077] The transmitting module includes a signal laser 311, a first polarization beam splitter 312 with an input end connected with an output end of the signal laser 311, a first IQ modulator 313 with an input end connected with a first output end of the first polarization beam splitter 312, a second IQ modulator 314 with an input end connected with a second output end of the first polarization beam splitter 312, and a polarization combiner 315 with input ends connected with output ends of the first IQ modulator 313 and the second IQ modulator 314 respectively; the signal laser 311 is used for transmitting an optical signal with 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 for modulating the optical signal, and an output end of the polarization combiner 315 is used for sending the modulated optical signal to the optical switch unit 4.

[0078] The receiving module comprises a local laser 316, a third polarization beam splitter 318, an input end of which is connected to an output end of the local laser 316, a second polarization beam splitter 317, a first 90° mixer 319, input ends of which are connected to a first output end of the second polarization beam splitter 317 and a first output end of the third polarization beam splitter 318 respectively, a second 90° mixer 3110, input ends of which are connected to a second output end of the second polarization beam splitter 317 and a second output end of the third polarization beam splitter 318 respectively, a first balanced detector 3111, an input end of which is connected to a first output end of the first 90° mixer 319, a second balanced detector 3112, an input end of which is connected to a second output end of the first 90° mixer 319, a third balanced detector 3113, an input end of which is connected to a first output end of the second 90° mixer 3110, a fourth balanced detector 3114, an input end of which is connected to a second output end of the second 90° mixer 3110, and an ADC module 3115, input ends of which are connected to output ends of the first balanced detector 3111, the second balanced detector 3112, the third balanced detector 3113 and the fourth balanced detector 3114 respectively, a DSP module 3116, an output end of which is connected to an output end of the ADC module 3115, and a driving control circuit 3117; the input end of the second polarization beam splitter 317 is used for receiving an optical signal from the optical switch unit 4, the ADC module 3115 and the DSP module 3116 are used for demodulating the signal, the driving control circuit 3117 is used for driving and controlling the high-speed optical module 31, loading original signals sent by a satellite platform data source (such as a sensing load) to the transmitting module, and sending the signals demodulated by the receiving module to a satellite platform data receiving end (such as a computing load).

[0079] The actual working process of the high-speed optical module 31 is as follows: the light output by the signal laser 311 is divided into two polarized lights by the first polarization beam splitter 312, 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 received optical signal at the receiving end and the light output by the local laser 316 are divided into two polarized lights by the second polarization beam splitter 317 and the third polarization beam splitter 318 respectively, the two beams of light in one polarization state are mixed by the first 90° mixer 319 and then enter the first balanced detector 3111 and the second balanced detector 3112 respectively, the two beams of light in another polarization state are mixed by the second 90° mixer 3110 and then enter the third balanced detector 3113 and the fourth balanced detector 3114 respectively, and the original signals are demodulated by the ADC and the DSP after the output of each balanced detector; the driving control circuit 3117 provides driving control for each device.

[0080] In the embodiment, in order to reduce the manufacturing cost, reference is made to Figure 3Both the transmitter 514 and the receiver 611 are transceiver integrated terminals. The transceiver integrated terminal includes a transceiver relay optical path 6111 connected to the output of the power amplifier 513 or the input 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 mounted on the mechanical turntable 6113.

[0081] The transceiver antenna 6112 is used to transmit optical signals into 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 to perform beam shaping processing; the PAT module 6114 is used to control the rotation angle of the mechanical turntable 6113, the transmission and reception direction of the transceiver antenna 6112, and the galvanometer direction of the transceiver relay optical path 6111, so as to realize the acquisition, tracking and aiming of the transmitted and received optical signals.

[0082] In practical applications, the optical switch unit 4 can be a MEMS optical switch, a magneto-optical switch, an electro-optical switch, or a silicon-based on-chip optical switch based on MZI / MRR. The optical switch unit 4 is equipped with multiple input and output ports to meet signal transmission requirements.

[0083] Based on the multi-stage multiplexing in optical transmitting branch unit 5 and the multi-stage demultiplexing in optical receiving branch unit 6, the multiplexing and demultiplexing of optical signal wavelengths are realized, resulting in a significant increase in system transmission rate compared to single wavelength. When two laser communication systems communicate, for one of the systems, the transmitted and received light wavelengths are different. If the transmitted wavelengths are λ1, ..., λ2... p The receiving wavelengths are λ'1, ..., λ' p If the emission wavelength is λ'1, ..., λ' p The receiving wavelengths are λ1, ..., λ p The transmit and receive wavelengths of the communication system are tunable, and it can be compatible with both wavelength states of a two-end system at the same time.

[0084] For the input terminals of each multi-stage multiplexing of different wavelengths in optical transmitting branch unit 5, only one or more ports can be used to achieve multi-level adjustable transmission rates for each transmitting branch; for the output terminals of each multi-stage demultiplexing of different wavelengths in optical receiving branch unit 6, only one or more ports can be used to achieve multi-level adjustable transmission rates for each receiving branch.

[0085] Meanwhile, this embodiment also provides a multi-channel transceiver satellite laser communication method based on an optical switch. The above-mentioned multi-channel transceiver satellite laser communication system based on an optical switch includes an optical signal transmission method, an optical signal reception method, a communication link transmission bit error rate test method, and a communication system self-test method.

[0086] 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;

[0087] Step a2, the driving control circuit loads the original signal 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;

[0088] 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;

[0089] Step a4, the optical transmission branch 51 multiplexes, amplifies and transmits the multiple modulated optical signals to the free space, and completes the optical signal transmission;

[0090] The optical signal receiving method comprises the following steps:

[0091] 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 receiving instruction;

[0092] Step b2, the optical receiving branch 61 amplifies the received optical signal in the free space, then demultiplexes and transmits it to the optical switch unit 4;

[0093] 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;

[0094] Step b4, the high-speed optical module 31 transmits the demodulated optical signal to the satellite platform data receiving end, and completes the optical signal receiving.

[0095] The communication link transmission error rate test method comprises the following steps:

[0096] Step c1, the external satellite platform sends a communication link transmission 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 error rate test instruction;

[0097] Step c2, the FPGA in the driving control circuit 3117 in the laser communication system A generates a pseudo-random binary sequence by itself, and sends it to the laser communication system B through the high-speed optical transceiver unit 3, the optical switch unit 4 and the optical transmitting branch unit 5.

[0098] Step c3, after the laser communication system B receives the optical signal, the optical signal is transmitted to the high-speed optical transceiver unit 3 through the optical receiving branch unit 6 and the optical switch unit 4, and the driving control circuit 3117 performs frame demodulation, synchronization and comparison on the signal, and then calculates the transmission error rate of the communication link.

[0099] The communication system self-test method comprises the following steps:

[0100] 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 transmitting branch unit 5 according to the optical signal transmission instruction;

[0101] Step d2, turn off the power amplifier 513 and the preamplifier 612;

[0102] Step d3, configure the connection relationship between the input and output ports of the optical switch, and configure 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;

[0103] Step d4, the FPGA in the driving control circuit 3117 generates a pseudo-random binary sequence by itself, and sends it to the high-speed optical transceiver unit 3 through the high-speed optical transceiver unit 3, the optical switch unit 4, the multi-stage multiplexing module 511 in the optical transmitting branch unit 5 and the transmitting end coupler 512, 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, and the driving control circuit 3117 performs frame demodulation, synchronization and comparison on the signal, and then calculates the error rate of the self-test line.

[0104] The multiplexing method described in the present application is wavelength division multiplexing. Table 1 below is a table of English abbreviations, English full names and Chinese meanings in the present application.

[0105] Table 1: Table of English abbreviations, English full names and Chinese meanings in the present application

[0106]

[0107] It should be pointed out finally that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the same. For those skilled in the art, the specific technical solutions described in the foregoing embodiments can be modified, or some technical features therein can be replaced equivalently, and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions protected by the present application.

Claims

1. A multi-channel transceiving integrated satellite laser communication system based on optical switch, characterized in that: it comprises a master control unit (1) and a power supply unit (2) electrically connected with an external satellite platform respectively, and a high-speed optical transceiver unit (3), an optical switch unit (4), an optical transmitting branch unit (5) and an optical receiving branch unit (6) connected with the master control unit (1) and the power supply unit (2) respectively; the master control unit (1) and the power supply unit (2) are connected with each other; the high-speed optical transceiver unit (3) is used for generating and modulating multi-channel high-speed optical signals according to the transmitting instruction of the master control unit (1), and / or demodulating and sending the received optical signals to the master control unit (1), and comprises m high-speed optical modules (31) capable of optical signal transceiving, m>1, m is an integer, and each high-speed optical module (31) is connected with the corresponding input end and output end of the optical switch unit (4) respectively; the optical transmitting branch unit (5) comprises n optical transmitting branches (51), n>1, n is an integer, the input end of each optical transmitting branch (51) is connected with the corresponding output end of the optical switch unit (4), the first output end is used for sending optical signals, and the second output end is connected with the corresponding input end of the optical switch unit (4); each optical transmitting branch (51) is used for multiplexing, amplifying and transmitting 2p-channel optical signals generated after the modulation of the high-speed optical module (31) in the high-speed optical transceiver unit (3) into the free space, p>1, p is an integer; the optical receiving branch unit (6) comprises n optical receiving branches (61), the first input end of each optical receiving branch (61) is used for receiving external optical signals, the second input end is connected with the corresponding output end of the optical switch unit (4), and the output end is connected with the corresponding input end of the optical switch unit (4); each optical receiving branch (61) is used for low-noise amplifying the weak optical signals received in the free space, then demultiplexing 2p optical signals and transmitting the 2p optical signals to the high-speed optical transceiver unit (3) through the optical switch unit (4) for demodulation; the master control unit (1) is used for controlling the high-speed optical transceiver unit (3), the optical switch unit (4), the optical transmitting branch unit (5) and the optical receiving branch unit (6) to receive or send signals according to the task instruction issued by the satellite platform; and the power supply unit (2) is used for supplying power to the master control unit (1), the high-speed optical transceiver unit (3), the optical switch unit (4), the optical transmitting branch unit (5) and the optical receiving branch unit (6) by using the electric energy provided by the satellite platform. 2.The multi-channel transceiving integrated satellite laser communication system based on optical switch according to claim 1, characterized in that: ​ ​ ​ The number of input ports of the optical switch unit (4) is defined as S in , and the number of output ports is defined as S out , then S in ≥ m + n + 2pn, S out ≥ m + n + 2pn ​ ​ Each of the light emission branch (51) includes input end and the corresponding output end of optical switch unit (4) connection multi-stage multiplexing module (511), input end and multi-stage multiplexing module (511) output end connection emission end coupler (512), input end and emission end coupler (512) first output end connection power amplifier (513) and input end and power amplifier (513) output end connection emission end machine (514);The second output end of the emission end coupler (512) is connected with the corresponding input end of the optical switch unit (4); The multi-stage multiplexing module (511) is used for wavelength division multiplexing 2p light signal into a communication line;The power amplifier (513) is used for high power amplification of optical signal;The emission end coupler (512) is used for realizing communication link self-test;The emission end machine (514) is used for emitting optical signal to free space.

3. The multi-channel transceiver integrated satellite laser communication system based on optical switch according to claim 1, characterized in that: Each of the light receiving branch (61) includes a receiving end machine (611), an input end and a preamplifier (612) connected to the output end of the receiving end machine (611), a first input end and a receiving end coupler (613) connected to the output end of the preamplifier (612), and a multi-stage demultiplexing module (614) connected to the receiving end coupler (613);The second input end of the receiving end coupler (613) is connected with the corresponding output end of the optical switch unit (4); The receiving end machine (611) is used for receiving optical signal from free space;The preamplifier (612) is used for low noise amplification of weak signal in received optical signal;The receiving end coupler (613) is used for realizing communication link self-test;The multi-stage demultiplexing module (614) is used for realizing separate filtering of different wavelength signals.

4. The multi-channel transceiver integrated satellite laser communication system based on optical switch according to claim 3, 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 (614), and the multi-stage multiplexing module (511), the emission end coupler (512), the power amplifier (513) and the emission end machine (514) in each of the light emission 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 of the light receiving branch (61) are connected by optical fiber.

5. The multi-channel transceiver integrated satellite laser communication system based on optical switch according to claim 4, 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. The multi-channel transceiver integrated satellite laser communication system based on optical switch according to claim 4, characterized in that: The modulation mode of the high-speed optical module (31) is DP-QPSK, which comprises a transmitting module, a receiving module, and a driving control circuit (3117) electrically connected with the transmitting module, the receiving module, a master control unit (1) and a power supply unit (2); The transmitting module comprises a signal laser (311), a first polarization beam splitter (312) with an input end connected with an output end of the signal laser (311), a first IQ modulator (313) with an input end connected with a first output end of the first polarization beam splitter (312), a second IQ modulator (314) with an input end connected with a second output end of the first polarization beam splitter (312), and a polarization beam combiner (315) with input ends connected with output ends of the first IQ modulator (313) and the second IQ modulator (314) respectively; the signal laser (311) is used for transmitting an optical signal of a preset wavelength according to a transmitting instruction of the master control unit (1), the first IQ modulator (313) and the second IQ modulator (314) are used for modulating the optical signal, and an output end of the polarization beam combiner (315) is used for sending the modulated optical signal to an optical switch unit (4); The receiving module comprises a local laser (316), a third polarization beam splitter (318) with an input end connected with an output end of the local laser (316), a second polarization beam splitter (317), a first 90° mixer (319) with input ends connected with a first output end of the second polarization beam splitter (317) and a first output end of the third polarization beam splitter (318) respectively, a second 90° mixer (3110) with input ends connected with a second output end of the second polarization beam splitter (317) and a second output end of the third polarization beam splitter (318) respectively, a first balanced detector (3111) with an input end connected with a first output end of the first 90° mixer (319), a second balanced detector (3112) with an input end connected with a second output end of the first 90° mixer (319), a third balanced detector (3113) with an input end connected with a first output end of the second 90° mixer (3110), a fourth balanced detector (3114) with an input end connected with a second output end of the second 90° mixer (3110), an ADC module (3115) with input ends connected with output ends of the first balanced detector (3111), the second balanced detector (3112), the third balanced detector (3113) and the fourth balanced detector (3114) respectively, and a DSP module (3116) with an input end connected with an output end of the ADC module (3115); the input end of the second polarization beam splitter (317) is used for receiving an optical signal from the optical switch unit (4), the ADC module (3115) and the DSP module (3116) are used for demodulating and processing the signal, and the driving control circuit (3117) is used for driving and controlling the high-speed optical module (31), loading original signals from a satellite platform data source to the transmitting module, and sending the demodulated signals of the receiving module to a satellite platform data receiving end.

7. The multi-channel transceiving integrated satellite laser communication system based on optical switch according to claim 6, characterized in that: the transmitting terminal (514) and the receiving terminal (611) are both transceiving integrated terminals, the transceiving integrated terminal comprises a transceiving relay optical path (6111) connected with the output end of the power amplifier (513) or the input end of the preamplifier (612), a transceiving antenna (6112) connected with the transceiving relay optical path (6111), a PAT module (6114) electrically connected with the main control unit (1), and a mechanical turntable (6113) electrically connected with the PAT module (6114); the transceiving relay optical path (6111) and the transceiving antenna (6112) are both arranged on the mechanical turntable (6113); the transceiving antenna (6112) is used for transmitting or receiving optical signals into the free space; the transceiving relay optical path (6111) is used for coupling conversion between the optical fiber signal and the free space optical signal, and performs beam shaping processing; the PAT module (6114) is used for controlling the rotation angle of the mechanical turntable (6113), the transceiving direction of the transceiving antenna (6112), and the galvanometer direction of the transceiving relay optical path (6111), so as to realize the capture, tracking and aiming of the transceiving optical signal.

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

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

10. The multi-transceiving integrated satellite laser communication method based on optical switch according to claim 9, characterized in that: It further comprises a communication link transmission bit error rate testing method and a communication system self-testing 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 testing instruction to the master control unit (1) of the laser communication system A and the laser communication system B according to actual needs, and the master 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 transmitting branch unit (5) according to the communication link transmission bit error rate testing instruction; Step c2, the FPGA in the drive control circuit (3117) in the laser communication system A generates a pseudo-random binary sequence, which is sent to the laser communication system B through the high-speed optical transceiver unit (3), the optical switch unit (4) and the optical transmitting branch unit (5); Step c3, after the laser communication system B receives the optical signal, it is transmitted to the high-speed optical transceiver unit (3) through the optical receiving branch unit (6) and the optical switch unit (4), and the drive control circuit (3117) counts the communication link transmission bit error rate after frame demodulation, synchronization and comparison; The communication system self-testing method comprises the following steps: Step d1, the external satellite platform sends an optical signal transmission instruction to the master control unit (1) according to actual needs, and the master control unit (1) controls the high-speed optical transceiver unit (3), the optical switch unit (4) and the optical transmitting branch unit (5) according to the optical signal transmission instruction; Step d2, turn off the power amplifier (513) and the preamplifier (612); Step d3, configure the input and output port connection relationship of the optical switch, and configure 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 transmitted back to the high-speed optical transceiver unit (3) through the multi-level multiplexing module (511) in the high-speed optical transceiver unit (3), the optical switch unit (4), the optical transmitting branch unit (5), the transmitting end coupler (512), the optical switch unit (4), the receiving end coupler (613) and the multi-level demultiplexing module (614) in the optical receiving branch unit (6), and the optical switch unit (4), and the drive control circuit (3117) counts the self-test line bit error rate after frame demodulation, synchronization and comparison.

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