Multi-target communication system and method

Abstract

The application discloses a multi-target communication system and method, which comprises an optical antenna array module, a transmitting channel link module and a receiving channel link module; the optical antenna array module is connected with the transmitting channel link module and the receiving channel link module respectively; the transmitting channel link module converts multi-target transmitting data into target transmitting communication optical signals; the optical antenna array module transmits the target transmitting communication optical signals; the optical antenna array module captures, tracks and aligns the received communication target signals to obtain target optical signals; and the receiving channel link module converts the target optical signals into multi-target communication receiving data. Compared with a traditional mechanical rotary table mechanism, the application saves the volume and power consumption, realizes point-to-multipoint communication, shortens the capturing scanning time and increases the tracking bandwidth on the basis of the control of the optical antenna array module and the capturing, tracking and alignment of the transmitting channel link module and the receiving channel link module on multiple targets.

Description

Technical Field

[0001] This invention relates to the field of space laser communication technology, and in particular to a multi-target communication system and method. Background Technology

[0002] Laser-based satellite communication systems, characterized by high speed, high security, no need for spectrum application, small terminal size, light weight, and low power consumption, are gradually becoming the development trend of satellite communication. With the large-scale deployment and implementation of low-Earth orbit satellites, satellite optical communication is evolving towards relay and networking, moving from point-to-point communication to point-to-multipoint communication. To achieve point-to-multipoint communication, satellite nodes need to be able to quickly establish or switch communication links with multiple other satellite nodes. The primary step in inter-satellite laser networking is to achieve rapid acquisition, tracking, and alignment (ATP) of multiple targets over a large area of ​​space. ATP performance directly affects link establishment time, switching time, and link stability; therefore, beam acquisition, tracking, and alignment (ATP) technology is one of the key technologies in satellite optical communication.

[0003] Current ATP (Optical Axis-Assisted Tracking) technologies mostly employ a coarse- and fine-axis composite control method. The coarse tracking ring uses a mechanical turntable to achieve a wide range of optical antenna rotation; the fine tracking ring uses a fast-reflecting mirror to achieve high-precision, small-range, rapid rotation; a high-precision mirror is installed in the transmitting optical path to achieve advanced alignment; and a high-frame-rate camera acquires the spatial position of a single target through beam splitting detection in the receiving optical path. Therefore, the ATP functional components often account for the majority of the system's weight, volume, and power consumption. In satellite networking requiring point-to-multipoint communication, using traditional ATP mechanical servo systems would lead to a significant increase in satellite payload weight, volume, and power consumption, thus limiting the feasibility of deploying optical communication payloads on satellites. Furthermore, due to mechanical damping and hysteresis, as well as the frame rate limitations of the area array detector, it is difficult to improve the acquisition time and tracking bandwidth of the ATP system.

[0004] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The main objective of this invention is to provide a multi-target communication system and method, which aims to solve the technical problems that traditional ATP mechanical servo systems cause satellite payload weight, volume and power consumption to increase exponentially, limiting the feasibility of deploying optical communication payloads on satellites, and making it difficult to improve the acquisition time and tracking bandwidth.

[0006] To achieve the above objectives, the present invention provides a multi-target communication system, which includes: an optical antenna array module, a transmit channel link module, and a receive channel link module;

[0007] The optical antenna array module is connected to both the transmit channel link module and the receive channel link module.

[0008] The transmission channel link module is used to convert multi-target transmission data into target transmission communication optical signals, and output the target transmission communication optical signals to the optical antenna array module;

[0009] The optical antenna array module is used to transmit communication optical signals from the target and receive communication target signals in the communication target space;

[0010] The optical antenna array module is also used to capture and track the received communication target signal, obtain the target optical signal, and output the target optical signal to the receiving channel link module;

[0011] The receiving channel link module is used to convert the target optical signal into multi-target communication receiving data.

[0012] Optionally, the receiving channel link module includes a first optical fiber splitter, a first laser, a mixer and photodetector array, a first analog-to-digital converter module, and a receiving data processing module;

[0013] The mixer and photodetector array are respectively connected to the first optical fiber splitter, the optical antenna array module and the first analog-to-digital converter module; the first laser is connected to the first optical fiber splitter; and the receiving data processing module is connected to the first analog-to-digital converter module.

[0014] The first optical fiber splitter is used to convert the light generated by the first laser into a first split optical signal and output the first split optical signal to the mixer and photodetector array;

[0015] The mixer and photodetector array is used to downconvert the first split optical signal and the target optical signal output by the optical antenna array module to obtain a downconverted electrical signal, and output the downconverted electrical signal to the first analog-to-digital converter module.

[0016] The first analog-to-digital converter module is used to convert the down-converted electrical signal into a digital received signal;

[0017] The receiving data processing module is used to convert the digital received signal into multi-target communication received data.

[0018] Optionally, the transmission channel link module includes a second fiber optic splitter, a second laser, a modulator array, a first digital-to-analog converter module, and a transmission data processing module;

[0019] The modulator array is connected to the second optical fiber splitter, the optical antenna array module, and the first digital-to-analog converter module, respectively; the second laser is connected to the second optical fiber splitter; and the transmission data processing module is connected to the first digital-to-analog converter module.

[0020] The launch data processing module is used to convert multi-target launch data into launch weighted data, and output the launch weighted data to the first digital-to-analog conversion module;

[0021] The first digital-to-analog converter module is used to convert the transmitted weighted data into an analog transmitted signal and output the analog transmitted signal to the modulator array;

[0022] The second fiber optic splitter is used to convert the light generated by the second laser into a second split optical signal, and output the second split optical signal to the modulator array;

[0023] The modulator array is used to modulate the second split optical signal with the analog transmission signal to obtain the target transmission communication optical signal, and output the target transmission communication optical signal to the optical antenna array module.

[0024] Optionally, the optical antenna array module includes an antenna array, which is distributed in the spatial elevation and azimuth directions. The distribution of the antenna array is not limited to circular arrays and square arrays.

[0025] Optionally, the multi-target communication system further includes: a transceiver channel correction module;

[0026] The transceiver channel correction module is connected to the optical antenna array module, the transmit channel link module, and the receive channel link module, respectively.

[0027] The transceiver channel correction module is used to specify a frame header without service scheduling as a correction frame, insert the correction frame into the correction sequence of each channel of the transmit channel link module for channel correction, obtain the transmit channel correction received signal through the optical antenna array module coupling loopback, and output the transmit channel correction received signal to the transmit channel link module.

[0028] The transceiver channel correction module is further configured to modulate the first branched optical signal output from the first laser with the correction frame to obtain a receiving channel correction transmission signal, and return it to the receiving channel link module through the coupling loop of the optical antenna array module to perform channel correction on each channel of the receiving channel link module.

[0029] Optionally, the transceiver channel correction module is further configured to designate a certain transmission channel of the transmission channel link module as the transmission reference channel, and to estimate the channel delay difference and channel amplitude phase difference of the other channels with reference to the transmission reference channel;

[0030] The transceiver channel correction module is further configured to designate a certain receiving channel of the receiving channel link module as the receiving reference channel, and to estimate the channel delay difference and channel amplitude phase difference of the other channels with reference to the receiving reference channel.

[0031] Optionally, the optical antenna array module is further configured to capture the received communication target signal through spatial spectrum estimation to obtain the spatial location of the communication target signal;

[0032] The optical antenna array module is also used to detect changes in the spatial position of the communication target signal based on the spatial position, and to obtain the tracking angle;

[0033] The optical antenna array module is also used to align the communication target signal according to the spatial position and the tracking angle, so that the target transmits a communication optical signal pointing towards the target.

[0034] Furthermore, to achieve the above objectives, this invention also proposes a multi-target communication method, which is applied to a multi-target communication system. The system includes an optical antenna array module, a transmit channel link module, and a receive channel link module; the optical antenna array module is connected to both the transmit channel link module and the receive channel link module; the method includes:

[0035] The transmission channel link module converts multi-target transmission data into target transmission communication optical signals, and outputs the target transmission communication optical signals to the optical antenna array module;

[0036] The optical antenna array module transmits communication optical signals from the target and receives communication target signals from the communication target space;

[0037] The optical antenna array module captures and tracks the received communication target signal, obtains the target optical signal, and outputs the target optical signal to the receiving channel link module;

[0038] The receiving channel link module converts the target optical signal into multi-target communication reception data.

[0039] Optionally, the receiving channel link module includes a first optical fiber splitter, a first laser, a mixer and photodetector array, a first analog-to-digital converter module, and a receiving data processing module; the mixer and photodetector array are respectively connected to the first optical fiber splitter, the optical antenna array module, and the first analog-to-digital converter module; the first laser is connected to the first optical fiber splitter; and the receiving data processing module is connected to the first analog-to-digital converter module.

[0040] The receiving channel link module converts the target optical signal into multi-target communication reception data, including:

[0041] The first optical fiber splitter converts the light generated by the first laser into a first split optical signal, and outputs the first split optical signal to the mixer and photodetector array;

[0042] The mixer and photodetector array down-converts the first split optical signal and the target optical signal output by the optical antenna array module to obtain a down-converted electrical signal, and outputs the down-converted electrical signal to the first analog-to-digital converter module.

[0043] The first analog-to-digital converter module converts the down-converted electrical signal into a digital received signal;

[0044] The receiving data processing module converts the digital received signal into multi-target communication received data.

[0045] Optionally, the transmission channel link module includes a second fiber optic splitter, a second laser, a modulator array, a first digital-to-analog converter module, and a transmission data processing module; the modulator array is connected to the second fiber optic splitter, the optical antenna array module, and the first digital-to-analog converter module, respectively; the second laser is connected to the second fiber optic splitter; and the transmission data processing module is connected to the first digital-to-analog converter module.

[0046] The transmission channel link module converts multi-target transmission data into target transmission communication optical signals and outputs the target transmission communication optical signals to the optical antenna array module, including:

[0047] The launch data processing module converts multi-target launch data into launch weighted data, and outputs the launch weighted data to the first digital-to-analog conversion module;

[0048] The first digital-to-analog converter module converts the transmitted weighted data into an analog transmitted signal and outputs the analog transmitted signal to the modulator array;

[0049] The second fiber optic splitter converts the light generated by the second laser into a second split optical signal, and outputs the second split optical signal to the modulator array;

[0050] The modulator array modulates the second split optical signal with the analog transmission signal to obtain the target transmission communication optical signal, and outputs the target transmission communication optical signal to the optical antenna array module.

[0051] This invention proposes a multi-target communication system, comprising: an optical antenna array module, a transmit channel link module, and a receive channel link module; wherein the optical antenna array module is connected to both the transmit and receive channel link modules; the transmit channel link module converts multi-target transmission data into target transmission communication optical signals and outputs the target transmission communication optical signals to the optical antenna array module; the optical antenna array module transmits the target transmission communication optical signals and receives communication target signals in the communication target space; the optical antenna array module also captures and tracks the received communication target signals to obtain target optical signals and outputs the target optical signals to the receive channel link module; the receive channel link module converts the target optical signals into multi-target communication reception data. Because this invention, based on the control of the optical antenna array module and combined with the transmit and receive channel link modules for capturing, tracking, and aligning multiple targets, saves volume, weight, and power consumption compared to traditional mechanical turntables and fast-reflecting mirrors, and achieves point-to-multipoint communication, thereby reducing capture and scanning time and increasing tracking bandwidth. Attached Figure Description

[0052] Figure 1 This is a structural block diagram of the first embodiment of the multi-target communication system of the present invention;

[0053] Figure 2 This is a structural block diagram of a second embodiment of the multi-target communication system of the present invention;

[0054] Figure 3 This is a schematic diagram of the structure of multi-target communication based on optical antenna array in the second embodiment of the multi-target communication system of the present invention;

[0055] Figure 4 This is a schematic diagram of a scenario in which the spatial spectrum method is used to capture two targets in space, according to the second embodiment of the multi-target communication system of the present invention.

[0056] Figure 5 This is a flowchart illustrating the first embodiment of the multi-target communication method of the present invention;

[0057] Figure 6 This is a flowchart illustrating the second embodiment of the multi-target communication method of the present invention.

[0058] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0059] It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0060] This invention provides a multi-target communication system, referring to... Figure 1 , Figure 1 This is a structural block diagram of the first embodiment of the multi-target communication system of the present invention.

[0061] In this embodiment, the multi-target communication system includes: an optical antenna array module 10, a transmit channel link module 20, and a receive channel link module 30.

[0062] The optical antenna array module 10 is connected to the transmit channel link module 20 and the receive channel link module 30, respectively.

[0063] The transmission channel link module 20 is used to convert multi-target transmission data into target transmission communication optical signals and output the target transmission communication optical signals to the optical antenna array module 10.

[0064] It should be noted that the optical antenna array module is a module composed of multiple optical antennas, which may include antenna arrays, fiber coupling, and optical processing, and is used for transmitting, receiving, and modulating light waves. In the receiving direction, it achieves the coupling of spatial light to the optical fiber, and in the transmitting direction, it enables the optical fiber to be collimated and transmitted into space through the antenna array.

[0065] Understandably, the transmit channel link module is a module in satellite communication that modulates and transforms baseband signals (voice, video, data, or other information) and outputs them to the optical antenna array module for propagation. It may include digital-to-analog converters, lasers, modulators, etc., but this embodiment does not limit this.

[0066] It should be understood that multi-target transmission data involves weighting different target data with their respective directions before transmitting it through an optical antenna array to improve communication speed and reliability. The target transmission communication optical signal is obtained by modulating and transforming the multi-target transmission data through the transmission channel link module.

[0067] In a specific implementation, the transmission channel link module weights the multi-target transmission data according to the target direction, then modulates and converts it into a target transmission communication optical signal, and outputs the target transmission communication optical signal to the optical antenna array module.

[0068] The optical antenna array module 10 is used to transmit the target's transmitted communication optical signal and receive the communication target signal in the communication target space;

[0069] The optical antenna array module 10 is also used to capture and track the received communication target signal, obtain the target optical signal, and output the target optical signal to the receiving channel link module 30;

[0070] In practical implementation, the optical antenna array module can acquire received signals. For targets appearing within the array antenna's field of view, spatial spectrum estimation methods can be used to obtain the elevation and azimuth angles of multiple targets, thus achieving target acquisition. After achieving multi-target acquisition, changes in the spatial position of the targets can be detected in real time, enabling target tracking. Finally, by combining the data from the acquisition and tracking, a beam pointing angle is formed, achieving alignment with the target.

[0071] The receiving channel link module 30 is used to convert the target optical signal into multi-target communication receiving data.

[0072] It should be noted that the receiving channel link module is used in satellite communication to modulate and convert the optical signal output from the optical antenna array module. Since the received signal in a satellite communication link is extremely weak, it needs to be amplified and converted by the receiving channel link module. The receiving channel link module may include mixers and photodetector arrays, lasers, analog-to-digital converters, etc., but this embodiment does not limit this.

[0073] Understandably, the target optical signal is a communication target signal obtained by the optical antenna array module through capture and tracking.

[0074] In a specific implementation, the receiving channel link module can capture and track the optical antenna array module, and convert the obtained communication target signal, the target optical signal, into multi-target communication receiving data.

[0075] This embodiment proposes a multi-target communication system, comprising: an optical antenna array module, a transmit channel link module, and a receive channel link module; the optical antenna array module is connected to both the transmit and receive channel link modules. The transmit channel link module weights the multi-target transmission data by target direction, modulates it into a target-transmitted communication optical signal, and outputs the target-transmitted communication optical signal to the optical antenna array module. The optical antenna array module transmits the target-transmitted communication optical signal and receives communication target signals in the communication target space. When the optical antenna array module receives communication target signals in the communication target space, it can collect the received signals. For targets appearing within the array antenna's field of view, spatial spectrum estimation can be used to obtain the elevation and azimuth angles of multiple targets, achieving target acquisition. After multi-target acquisition, the spatial position changes of the targets can be detected in real time, enabling target tracking. Finally, the data from the acquisition and tracking are combined to form a beam pointing angle, achieving alignment with the communication target. The receiving channel link module can capture and track the optical antenna array module, and convert the acquired target optical signal into multi-target communication reception data. Because this invention, based on the control of the optical antenna array module, combines the transmitting and receiving channel link modules to capture, track, and align multiple targets, compared to traditional mechanical turntables and fast-reflecting mirrors, it saves volume, weight, and power consumption, achieves point-to-multipoint communication, thereby reducing acquisition and scanning time and increasing tracking bandwidth.

[0076] refer to Figure 2 , Figure 2 This is a structural block diagram of a second embodiment of the multi-target communication system of the present invention.

[0077] Based on the first embodiment described above, in this embodiment, to improve the accuracy of the receiving channel link module, such as... Figure 2 As shown, the receiving channel link module 30 includes a first optical fiber splitter 31, a first laser 32, a mixer and photodetector array 33, a first analog-to-digital converter 34, and a receiving data processing module 35.

[0078] The mixer and photodetector array 33 is connected to the first optical fiber splitter 31, the optical antenna array module 10 and the first analog-to-digital converter module 34, respectively; the first laser 32 is connected to the first optical fiber splitter 31; and the receiving data processing module 35 is connected to the first analog-to-digital converter module 34.

[0079] The first optical fiber splitter 31 is used to convert the light generated by the first laser into a first split optical signal and output the first split optical signal to the mixer and photodetector array;

[0080] It should be noted that the receiving channel link module may include a mixer and photodetector array, a laser, an optical fiber splitter, an analog-to-digital converter, and a receiving data processing module, wherein the data processing module can be used for weighted processing of the received data.

[0081] Understandably, a first fiber splitter is a method that can distribute the light generated by a first laser to multiple output ports or combine light from multiple input ports into one output port to achieve the distribution and convergence of optical signals.

[0082] It should be noted that the mixer and photodetector array is a device used in satellite communication to generate a lower-frequency signal by beating the received optical signal and the local optical signal. A photodetector array is a device used to detect optical signals and can be composed of multiple photodiodes or avalanche diodes, etc. The mixer and photodetector array can down-convert the first split optical signal and the target optical signal output from the optical antenna array module.

[0083] The mixer and photodetector array 33 is used to downconvert the first split optical signal and the target optical signal output by the optical antenna array module 10 to obtain a downconverted electrical signal, and output the downconverted electrical signal to the first analog-to-digital converter module 34.

[0084] The first analog-to-digital converter module 34 is used to convert the down-converted electrical signal into a digital received signal;

[0085] It should be noted that the first analog-to-digital converter module is used in satellite communication to convert analog signals into digital signals. It can convert continuous analog signals into discrete digital signals so that the receiving equipment can transmit and process them smoothly.

[0086] The receiving data processing module 35 is used to convert the digital received signal into multi-target communication received data.

[0087] It should be noted that the receiving data processing module is used to perform receiving weighting on the digital received signal converted by the first analog-to-digital converter module, as well as de-mapping, clock recovery, frequency offset estimation, equalization, demodulation, decoding, and frame de-framing, thereby obtaining multi-target communication received data.

[0088] In practical implementation, for ease of understanding, please refer to... Figure 3 , Figure 3 This is a schematic diagram of the structure of multi-target communication based on an optical antenna array in the second embodiment of the multi-target communication system of the present invention. Figure 3As shown, branch 1 is the first fiber branch, laser 1 is the first laser, analog-to-digital converter 1 is the first analog-to-digital converter module, the optical antenna array and front end are optical antenna array modules, and the receiving data processing module can perform receiving channel correction, receiving weighting, and receiving data processing on the digital received signal converted by the first analog-to-digital converter module. Specifically, the optical signal output from the optical antenna array and the various branch optical signals generated by laser 1 are mixed and then down-converted by the detector array, and converted into a digital signal by analog-to-digital converter 1. The received data is divided into two paths: one path acquires the elevation and azimuth angles of the multi-target beam; the other path performs receiving weighting based on the current elevation and azimuth angle feature vector and the weighting coefficients formed by the correction coefficients of each receiving channel. The data after weighting processing of each channel is processed according to common de-layer mapping, clock recovery, frequency offset estimation, equalization, demodulation, decoding, and deframing to obtain single / multi-target received data.

[0089] Furthermore, such as Figure 2 As shown, the transmission channel link module 20 in this embodiment includes a second optical fiber splitter 21, a second laser 22, a modulator array 23, a first digital-to-analog converter module 24, and a transmission data processing module 25;

[0090] The modulator array 23 is connected to the second optical fiber splitter 21, the optical antenna array module 10 and the first digital-to-analog converter module 24 respectively; the second laser 22 is connected to the second optical fiber splitter 21; and the transmission data processing module 25 is connected to the first digital-to-analog converter module 24.

[0091] The transmission data processing module 25 is used to convert multi-target transmission data into transmission weighted data, and output the transmission weighted data to the first digital-to-analog conversion module 24;

[0092] The first digital-to-analog converter module 24 is used to convert the transmitted weighted data into an analog transmitted signal and output the analog transmitted signal to the modulator array 23;

[0093] The second fiber optic branch 21 is used to convert the light generated by the second laser 22 into a second branched optical signal and output the second branched optical signal to the modulator array 23;

[0094] The modulator array 23 is used to modulate the second split optical signal with the analog transmission signal to obtain the target transmission communication optical signal, and output the target transmission communication optical signal to the optical antenna array module 10.

[0095] It should be noted that the transmission channel link module may include a transmission data processing module, a digital-to-analog converter, a laser, an optical fiber splitter and modulator array. The transmission data processing module can be used to perform weighting, correction and other processing on the transmitted data.

[0096] Understandably, a second fiber splitter is a method that can distribute the light generated by a second laser to multiple output ports or combine light from multiple input ports into one output port to achieve the distribution and convergence of optical signals.

[0097] It should be understood that a modulator array is a device used in satellite communications to change certain characteristics (frequency, phase, amplitude, etc.) of a signal to carry digital signal information. The modulator array can modulate the second split optical signal with the analog transmission signal to obtain the target transmission communication optical signal, and then output the target transmission communication optical signal to the optical antenna array module.

[0098] It should be noted that the first digital-to-analog converter module is used in satellite communication to convert digital signals into analog signals. It can convert discrete digital signals into continuous analog signals so that the optical antenna array can transmit signals.

[0099] Understandably, the transmission data processing module is used to perform general framing, encoding, and multi-layer data mapping on multi-target transmission data, thereby obtaining transmission weighted data.

[0100] In practical implementation, for ease of understanding, such as Figure 3 As shown, branch 2 is the second fiber branch, laser 2 is the second laser, digital-to-analog converter 1 is the first digital-to-analog converter module, the optical antenna array and front end are optical antenna array modules, and the transmission data processing module can perform transmission data processing, transmission weighting, and transmission channel correction processing on single / multi-target transmission data. Specifically, single / multi-target transmission data is processed according to single or multiple channels, including general framing, encoding, and multi-layer data mapping, to form baseband data for each channel. Based on the azimuth and elevation angles, lead alignment angles, and correction amounts corresponding to different wavelengths of the antenna array's transmission and reception, combined with the channel correction amplitude and phase errors, weighting coefficients are formed for each transmission channel, and the baseband data of each channel is weighted. Then, through digital-to-analog conversion, the output is sent to the modulator array to modulate the transmission signals of each branch of laser 2, and the output is sent to the optical antenna array.

[0101] Furthermore, considering the calibration of signal transmission and reception, the multi-target communication system in this embodiment also includes: a transceiver channel calibration module;

[0102] The transceiver channel correction module is connected to the optical antenna array module 10, the transmit channel link module 20, and the receive channel link module 30, respectively.

[0103] The transceiver channel correction module is used to specify a frame header without service scheduling as a correction frame, insert the correction frame into the correction sequence of each channel of the transmit channel link module 20 for channel correction, obtain the transmit channel correction received signal through the optical antenna array module coupling loopback, and output the transmit channel correction received signal to the transmit channel link module 20.

[0104] The transceiver channel correction module is further configured to modulate the first branched optical signal output from the first laser with the correction frame to obtain a receiving channel correction transmission signal, and return it to the receiving channel link module 30 through the coupling loop of the optical antenna array module to perform channel correction on each channel of the receiving channel link module 30.

[0105] It should be noted that the transceiver channel correction module may include transceiver channel correction, transmit channel correction of received signal, photodetector, analog-to-digital converter 2, receive channel correction of transmitted signal, digital-to-analog converter 2, modulator, transceiver channel amplitude and phase error estimation and other processing procedures.

[0106] In practical implementation, for ease of understanding, please refer to... Figure 3 The transceiver channel correction module may include a photodetector and an analog-to-digital converter 2. Specifically, in the transceiver channel correction module, channel correction can specify a frame without service scheduling as the correction frame. The correction frame carries an identifier in its frame header information to distinguish it from service frame headers. Transceiver correction sequences for each channel are inserted into the correction frame in a time-division multiplexing manner for channel correction. To ensure signal-to-noise ratio and measurement accuracy, correction sequences with good autocorrelation characteristics, such as M-sequences or ZC-sequences (Zadoff-Chu), can be selected. In the transmit channel correction direction, correction sequences are inserted into the correction frame in time-slots. The correction sequences pass through each transmit channel and are coupled back to the transmit channel correction signal in the optical antenna. Then, through the photodetector and analog-to-digital converter 2, the channel amplitude phase difference and time delay difference are estimated. In the receive channel correction direction, correction sequences can be inserted into the correction frame in time-slots. After digital-to-analog converter 2, the light split from laser 1 is modulated to generate the receive channel correction transmit signal. After entering the optical antenna array, it is coupled to each receive antenna channel. The correction sequence passes through each receive channel to estimate the receive channel amplitude phase difference and time delay difference.

[0107] Furthermore, in this embodiment, the transceiver channel correction module is also used to designate a certain transmission channel of the transmission channel link module 20 as the transmission reference channel, and the other channels use the transmission reference channel as a reference to estimate the channel delay difference and channel amplitude phase difference;

[0108] The transceiver channel correction module is also used to designate a certain receiving channel of the receiving channel link module 30 as the receiving reference channel, and to estimate the channel delay difference and channel amplitude phase difference of the other channels with reference to the receiving reference channel.

[0109] In practical implementation, when estimating channel delay difference, a certain receiving channel and transmitting channel can be designated as reference channels. A known sequence with good autocorrelation characteristics is sent and looped back through each channel. The data received in the loopback is correlated with the known sequence, and the delay difference between different channels and the reference channel is estimated by comparing the positions of the correlation peaks.

[0110] In channel amplitude and phase difference estimation, space optical communication uses narrow-linewidth light sources, which are narrowband signals. Channel correction for narrowband signals needs to consider the amplitude and phase errors of the center wavelength. Based on the characteristics of linear time-invariant systems, the channel output can be expressed as the convolution of the signal input and the channel transfer function. First, performing a Fourier transform on the channel correction signal yields the output signal of the reference channel:

[0111] X ref (ω)=FFT(s(n)*h ref (n))=S(ω)H ref (ω);

[0112] The output signals of the remaining channels are:

[0113] X i (ω)=FFT(s(n)*h i (n))=S(ω)H i (ω);

[0114] In the formula, This represents the frequency domain output of the reference channel. For the reference channel transfer function; This represents the frequency domain output of the i-th channel among the remaining channels. The transfer function for the i-th channel of the remaining channels; because and It is known that, through calculation, we can obtain The value of is obtained, that is, the frequency response of each channel at the center wavelength.

[0115] After selecting a reference channel and setting its correction factor to 1, the correction factors for the remaining channels are:

[0116] W i (ω)=H ref / H i (ω)=a i e jθ ;

[0117] Where ai is the channel correction amplitude compensation coefficient. The phase compensation coefficients for the channel correction are used; based on the time-varying nature of the channel changes, the correction compensation coefficients for the receiving and transmitting channels are periodically obtained. The received and transmitted data are multiplied by the correction coefficients in conjugate, which makes the amplitude and phase responses of each channel consistent.

[0118] Furthermore, in this embodiment, the optical antenna array module 10 includes an antenna array, which is distributed in the spatial elevation and azimuth directions. The distribution of the antenna array is not limited to circular arrays and square arrays.

[0119] Furthermore, the optical antenna array module 10 described in this embodiment is also used to capture the received communication target signal through spatial spectrum estimation to obtain the spatial position of the communication target signal;

[0120] The optical antenna array module 10 is also used to detect changes in the spatial position of the communication target signal based on the spatial position, and to obtain a tracking angle;

[0121] The optical antenna array module 10 is also used to align the communication target signal according to the spatial position and the tracking angle, so that the target transmits a communication optical signal pointing towards the target.

[0122] It should be noted that the tracking angle is the target spatial angle obtained by real-time detection of changes in the target's spatial position after multi-target acquisition is achieved.

[0123] In practical implementation, the key technology for the acquisition, tracking, and alignment functions of the optical antenna array module is the acquisition of the spatial azimuth and elevation angles of the communication target. By collecting the signals received by the optical antenna array, for targets appearing within the array antenna's field of view, the elevation and azimuth angles of multiple targets can be obtained using spatial spectrum estimation methods, thus achieving the acquisition of the communication target. Based on the characteristics that different targets are spatially incoherent and orthogonal to noise, the Multiple Signal Classification (MUSIC) method in spatial spectrum estimation can be used. Its processing procedure is as follows:

[0124] Suppose N target signals are incident on an array with M elements, and the received signal X is obtained:

[0125]

[0126] Where A is the general expression for the array manifold matrix, and different arrays are simplified to special models according to the actual situation; S is the signal vector; N is Gaussian white noise with a mean of 0 and a variance of σ².

[0127] Furthermore, φm，k =φ m (θ k , Φ k ), m=0, 1,..., M-1; k=1, 2,..., N;

[0128] Where, (θ k , Φ k () represents the spatial azimuth and elevation angle of the received signal.

[0129] First, the covariance matrix R can be calculated by receiving the signal X through the array;

[0130] Perform eigenvalue decomposition on R, and then sort the eigenvalues ​​in order of magnitude: λ1≥λ2≥...≥λN≥σ2. At the same time, obtain the eigenvalues ​​corresponding to the noise: λN+1=λN+2=...=λM=σ2, and the eigenvectors u1, u2,...uN and uN+1, uN+2,...uM corresponding to the signal and noise eigenvalues.

[0131] The eigenvalues ​​and corresponding eigenvectors of the signal and noise constitute the signal subspace and noise subspace, respectively; here we define:

[0132] G=[uN+1,uN+2,...uM]∈CM×(MN);

[0133] It can be seen that,

[0134] The pseudospectral of the signal is calculated as follows:

[0135]

[0136] Perform a peak search on the pseudo-spectrum to find the corresponding peaks of the N largest peaks in Pmusic. That is, N target spatial angles.

[0137] For space optical communication, if it is clear which targets are being communicated with at any given time, then the determination of the number of N signals can be eliminated, thus simplifying the calculation.

[0138] Taking a 32×32 uniform array as an example, with the spacing between array elements in each direction of the azimuth and elevation axes being d, the manifold matrix of the 32 array elements on the azimuth axis is:

[0139]

[0140] The manifold matrix of the 32 elements on the pitch axis is as follows:

[0141]

[0142] The receiver array manifold matrix can be represented as the Khatri-Rao product of Ay and Ax.

[0143] At this time, refer to Figure 4 , Figure 4 This is a schematic diagram illustrating the spatial spectrum method for capturing two spatial targets in the second embodiment of the multi-target communication system of the present invention. Simulation results, using a wavelength of 1550 nm and a communication rate of 2.5 Gbps @ SNR = 10, show that the above spatial spectrum processing method can achieve the following results: Figure 4 As shown, it can simultaneously acquire the spatial positions of two arbitrarily set targets (azimuth -1°, elevation 0.1°) and (azimuth 5°, elevation 0.5°).

[0144] After achieving multi-target acquisition, the spatial position changes of the target can be detected in real time, and the target spatial angle is the tracking angle.

[0145] In satellite optical communication, due to the high speed of satellite movement, it is necessary to consider the lead alignment angle, which is currently calculated based on ephemeris or GPS information.

[0146] By combining the tracking angle and the lead alignment angle, the required transmission beam pointing angle of the antenna array at the current moment is determined, achieving alignment with the communication target. This alignment is achieved by weighting the data transmitted from each channel.

[0147] Given a fixed array element distribution, the beamforming weighting coefficients are determined by the pointing angle. Taking a planar array antenna as an example, let the element plane be XOY, the normal be the Z-axis, the row spacing be dx, the column spacing be dy, and the required beam pointing azimuth and elevation angles be (As, Es). Then, the weighted phase of the channel corresponding to the (m, n)th element is:

[0148] φ mn =n*φ x +m*φ y ;

[0149] in,

[0150]

[0151]

[0152] The multi-layer data for different targets are conjugately multiplied with the weighting coefficients of the target direction and output to each antenna element to form a beam pointing to multiple targets, thereby realizing the alignment function.

[0153] This embodiment, based on existing optical phased array front-end control, combines multi-antenna digital signal processing technology to propose end-to-end channel amplitude and phase correction. It utilizes spatial spectrum estimation and digital beamforming to achieve acquisition, tracking, and alignment of multiple targets, realizing point-to-multipoint communication. Compared to traditional space optical communication systems, it eliminates mechanical turntables and fast-reflecting mirrors, significantly saving size, weight, and power consumption. Due to the flexible beam control using electronic methods, acquisition and scanning time can be reduced, increasing the system tracking bandwidth. Compared to current phased array space optical communication systems, this embodiment achieves end-to-end channel amplitude, phase, and time delay correction. Employing spatial spectrum estimation and digital waveform shaping techniques, it can simultaneously acquire, track, align, and communicate with multiple targets. Furthermore, this method is easily integrated with existing optical communication functions, maximizing the reuse of existing point-to-point communication capabilities.

[0154] refer to Figure 5 The present invention provides a multi-target communication system and a multi-target communication method. Figure 5 This is a flowchart illustrating a first embodiment of the multi-target communication method of the present invention. The system includes an optical antenna array module, a transmit channel link module, and a receive channel link module; the optical antenna array module is connected to both the transmit channel link module and the receive channel link module; the method includes:

[0155] Step S10: The transmission channel link module converts the multi-target transmission data into target transmission communication optical signals and outputs the target transmission communication optical signals to the optical antenna array module.

[0156] It should be noted that the optical antenna array module is a module composed of multiple optical antennas, which may include antenna arrays, fiber coupling, and optical processing, and is used for transmitting, receiving, and modulating light waves. In the receiving direction, it achieves the coupling of spatial light to the optical fiber, and in the transmitting direction, it enables the optical fiber to be collimated and transmitted into space through the antenna array.

[0157] Understandably, the transmit channel link module is a module in satellite communication that modulates and transforms baseband signals (voice, video, data, or other information) and outputs them to the optical antenna array module for propagation. It may include digital-to-analog converters, lasers, modulators, etc., but this embodiment does not limit this.

[0158] It should be understood that multi-target transmission data involves weighting different target data with their respective directions before transmitting it through an optical antenna array to improve communication speed and reliability. The target transmission communication optical signal is obtained by modulating and transforming the multi-target transmission data through the transmission channel link module.

[0159] Step S20: The optical antenna array module transmits the target transmission communication optical signal and receives the communication target signal in the communication target space.

[0160] Step S30: The optical antenna array module captures and tracks the received communication target signal, obtains the target optical signal, and outputs the target optical signal to the receiving channel link module.

[0161] In practical implementation, the optical antenna array module can acquire received signals. For targets appearing within the array antenna's field of view, spatial spectrum estimation methods can be used to obtain the elevation and azimuth angles of multiple targets, thus achieving target acquisition. After achieving multi-target acquisition, changes in the spatial position of the targets can be detected in real time, enabling target tracking. Finally, by combining the data from the acquisition and tracking, a beam pointing angle is formed, achieving alignment with the target.

[0162] Step S40: The receiving channel link module converts the target optical signal into multi-target communication receiving data.

[0163] It should be noted that the receiving channel link module is used in satellite communication to modulate and convert the optical signal output from the optical antenna array module. Since the received signal in a satellite communication link is extremely weak, it needs to be amplified and converted by the receiving channel link module. The receiving channel link module may include mixers and photodetector arrays, lasers, analog-to-digital converters, etc., but this embodiment does not limit this.

[0164] Understandably, the target optical signal is a communication target signal obtained by the optical antenna array module through capture and tracking.

[0165] In a specific implementation, the receiving channel link module can capture and track the optical antenna array module, and convert the obtained communication target signal, the target optical signal, into multi-target communication receiving data.

[0166] The transmit channel link module described in this embodiment can weight multi-target transmission data according to the target direction, then modulate and convert it into a target transmission communication optical signal, and output the target transmission communication optical signal to the optical antenna array module. The optical antenna array module is used to transmit the target transmission communication optical signal and receive communication target signals in the communication target space. When the optical antenna array module receives the communication target signals in the communication target space, it can collect the received signals. For targets appearing within the field of view of the array antenna, the elevation and azimuth angles of multiple targets can be obtained using spatial spectrum estimation methods to achieve target acquisition. After achieving multi-target acquisition, the spatial position changes of the targets can be detected in real time to achieve target tracking. Then, the data from the acquisition and tracking are combined to form a beam pointing angle to achieve alignment with the communication target. The receive channel link module can acquire and track the target signals obtained by the optical antenna array module, and convert the target optical signals into multi-target communication reception data. Because this invention, based on the control of the optical antenna array module, combines the transmission channel link module and the receiving channel link module to acquire, track and align multiple targets, compared with traditional mechanical turntables and fast-reflecting mirrors, it saves volume, weight and power consumption, realizes point-to-multipoint communication, thereby reducing the acquisition and scanning time and increasing the tracking bandwidth.

[0167] Reference Figure 6 , Figure 6 This is a flowchart illustrating the second embodiment of the multi-target communication method of the present invention, based on the above. Figure 5 The illustrated embodiment presents a second embodiment of the multi-target communication method of the present invention.

[0168] In this embodiment, the receiving channel link module includes a first optical fiber splitter, a first laser, a mixer and photodetector array, a first analog-to-digital converter module, and a receiving data processing module; the mixer and photodetector array are respectively connected to the first optical fiber splitter, the optical antenna array module, and the first analog-to-digital converter module; the first laser is connected to the first optical fiber splitter; and the receiving data processing module is connected to the first analog-to-digital converter module.

[0169] Step S40 includes:

[0170] Step S41: The first optical fiber splitter converts the light generated by the first laser into a first split optical signal and outputs the first split optical signal to the mixer and photodetector array.

[0171] It should be noted that the receiving channel link module may include a mixer and photodetector array, a laser, an optical fiber splitter, an analog-to-digital converter, and a receiving data processing module, wherein the data processing module can be used for weighted processing of the received data.

[0172] Understandably, a first fiber splitter is a method that can distribute the light generated by a first laser to multiple output ports or combine light from multiple input ports into one output port to achieve the distribution and convergence of optical signals.

[0173] It should be noted that a mixer and photodetector array is a device used in satellite communications to combine two signals of different frequencies to generate a new frequency signal. A photodetector array is a device used to detect optical signals and can be composed of multiple photodiodes or avalanche diodes, etc. The mixer and photodetector array can down-convert the first split optical signal and the target optical signal output from the optical antenna array module.

[0174] Step S42: The mixer and photodetector array down-converts the first split optical signal and the target optical signal output by the optical antenna array module to obtain a down-converted electrical signal, and outputs the down-converted electrical signal to the first analog-to-digital converter module.

[0175] Step S43: The first analog-to-digital converter module converts the down-converted electrical signal into a digital received signal.

[0176] It should be noted that the first analog-to-digital converter module is used in satellite communication to convert analog signals into digital signals. It can convert continuous analog signals into discrete digital signals so that the receiving equipment can transmit and process them smoothly.

[0177] Step S44: The receiving data processing module converts the digital received signal into multi-target communication received data.

[0178] It should be noted that the receiving data processing module is used to perform receiving weighting on the digital received signal converted by the first analog-to-digital converter module, as well as de-mapping, clock recovery, frequency offset estimation, equalization, demodulation, decoding, and frame de-framing, thereby obtaining multi-target communication received data.

[0179] In practical implementation, for ease of understanding, please refer to... Figure 3 ,like Figure 3As shown, branch 1 is the first fiber branch, laser 1 is the first laser, analog-to-digital converter 1 is the first analog-to-digital converter module, the optical antenna array and front end are optical antenna array modules, and the receiving data processing module can perform receiving channel correction, receiving weighting, and receiving data processing on the digital received signal converted by the first analog-to-digital converter module. Specifically, the optical signal output from the optical antenna array and the various branch optical signals generated by laser 1 are mixed and then down-converted by the detector array, and converted into a digital signal by analog-to-digital converter 1. The received data is divided into two paths: one path acquires the elevation and azimuth angles of the multi-target beam; the other path performs receiving weighting based on the current elevation and azimuth angle feature vector and the weighting coefficients formed by the correction coefficients of each receiving channel. The data after weighting processing of each channel is processed according to common de-layer mapping, clock recovery, frequency offset estimation, equalization, demodulation, decoding, and deframing to obtain single / multi-target received data.

[0180] Furthermore, in this embodiment, the transmission channel link module includes a second optical fiber splitter, a second laser, a modulator array, a first digital-to-analog converter module, and a transmission data processing module; the modulator array is connected to the second optical fiber splitter, the optical antenna array module, and the first digital-to-analog converter module, respectively; the second laser is connected to the second optical fiber splitter; and the transmission data processing module is connected to the first digital-to-analog converter module.

[0181] In this embodiment, step S10 includes: the transmission data processing module converts multi-target transmission data into transmission weighted data and outputs the transmission weighted data to the first digital-to-analog converter module; the first digital-to-analog converter module converts the transmission weighted data into an analog transmission signal and outputs the analog transmission signal to the modulator array; the second fiber optic splitter converts the light generated by the second laser into a second split optical signal and outputs the second split optical signal to the modulator array; the modulator array modulates the second split optical signal with the analog transmission signal to obtain a target transmission communication optical signal and outputs the target transmission communication optical signal to the optical antenna array module.

[0182] It should be noted that the transmission channel link module may include a transmission data processing module, a digital-to-analog converter, a laser, an optical fiber splitter and modulator array. The transmission data processing module can be used to perform weighting, correction and other processing on the transmitted data.

[0183] Understandably, a second fiber splitter is a method that can distribute the light generated by a second laser to multiple output ports or combine light from multiple input ports into one output port to achieve the distribution and convergence of optical signals.

[0184] It should be understood that a modulator array is a device used in satellite communications to change certain characteristics (frequency, phase, amplitude, etc.) of a signal to carry digital signal information. The modulator array can modulate the second split optical signal with the analog transmission signal to obtain the target transmission communication optical signal, and then output the target transmission communication optical signal to the optical antenna array module.

[0185] It should be noted that the first digital-to-analog converter module is used in satellite communication to convert digital signals into analog signals. It can convert discrete digital signals into continuous analog signals so that the optical antenna array can transmit signals.

[0186] Understandably, the transmission data processing module is used to perform general framing, encoding, and multi-layer data mapping on multi-target transmission data, thereby obtaining transmission weighted data.

[0187] In practical implementation, for ease of understanding, such as Figure 3 As shown, branch 2 is the second fiber branch, laser 2 is the second laser, digital-to-analog converter 1 is the first digital-to-analog converter module, the optical antenna array and front end are optical antenna array modules, and the transmission data processing module can perform transmission data processing, transmission weighting, and transmission channel correction processing on single / multi-target transmission data. Specifically, single / multi-target transmission data is processed according to single or multiple channels, including general framing, encoding, and multi-layer data mapping, to form baseband data for each channel. Based on the azimuth and elevation angles, lead alignment angles, and correction amounts corresponding to different wavelengths of the antenna array's transmission and reception, combined with the channel correction amplitude and phase errors, weighting coefficients are formed for each transmission channel, and the baseband data of each channel is weighted. Then, through digital-to-analog conversion, the output is sent to the modulator array to modulate the transmission signals of each branch of laser 2, and the output is sent to the optical antenna array.

[0188] This embodiment, based on existing optical phased array front-end control, combines multi-antenna digital signal processing technology to propose end-to-end channel amplitude and phase correction. It utilizes spatial spectrum estimation and digital beamforming to achieve acquisition, tracking, and alignment of multiple targets, realizing point-to-multipoint communication. Compared to traditional space optical communication systems, it eliminates mechanical turntables and fast-reflecting mirrors, significantly saving size, weight, and power consumption. Due to the flexible beam control using electronic methods, acquisition and scanning time can be reduced, increasing the system tracking bandwidth. Compared to current phased array space optical communication systems, this embodiment achieves end-to-end channel amplitude, phase, and time delay correction. Employing spatial spectrum estimation and digital waveform shaping techniques, it can simultaneously acquire, track, align, and communicate with multiple targets. Furthermore, this method is easily integrated with existing optical communication functions, maximizing the reuse of existing point-to-point communication capabilities.

[0189] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0190] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0191] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as read-only memory / random access memory, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0192] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A multi-target communication system, characterized in that, The multi-target communication system includes: an optical antenna array module, a transmit channel link module, and a receive channel link module; The optical antenna array module is connected to both the transmit channel link module and the receive channel link module. The transmission channel link module is used to convert multi-target transmission data into target transmission communication optical signals, and output the target transmission communication optical signals to the optical antenna array module; The optical antenna array module is used to transmit communication optical signals from the target and receive communication target signals in the communication target space; The optical antenna array module is also used to capture and track the received communication target signal, obtain the target optical signal, and output the target optical signal to the receiving channel link module; The receiving channel link module is used to convert the target optical signal into multi-target communication receiving data; The receiving channel link module includes a first optical fiber splitter, a first laser, a mixer and photodetector array, a first analog-to-digital converter module, and a receiving data processing module; The mixer and photodetector array are respectively connected to the first optical fiber splitter, the optical antenna array module and the first analog-to-digital converter module; the first laser is connected to the first optical fiber splitter; and the receiving data processing module is connected to the first analog-to-digital converter module. The first optical fiber splitter is used to convert the light generated by the first laser into a first split optical signal and output the first split optical signal to the mixer and photodetector array; The mixer and photodetector array is used to downconvert the first split optical signal and the target optical signal output by the optical antenna array module to obtain a downconverted electrical signal, and output the downconverted electrical signal to the first analog-to-digital converter module. The first analog-to-digital converter module is used to convert the down-converted electrical signal into a digital received signal; The receiving data processing module is used to convert the digital received signal into multi-target communication received data; The transmission channel link module includes a second optical fiber splitter, a second laser, a modulator array, a first digital-to-analog converter module, and a transmission data processing module; The modulator array is connected to the second optical fiber splitter, the optical antenna array module, and the first digital-to-analog converter module, respectively; the second laser is connected to the second optical fiber splitter; and the transmission data processing module is connected to the first digital-to-analog converter module. The launch data processing module is used to convert multi-target launch data into launch weighted data, and output the launch weighted data to the first digital-to-analog conversion module; The first digital-to-analog converter module is used to convert the transmitted weighted data into an analog transmitted signal and output the analog transmitted signal to the modulator array; The second fiber optic splitter is used to convert the light generated by the second laser into a second split optical signal, and output the second split optical signal to the modulator array; The modulator array is used to modulate the second split optical signal with the analog transmission signal to obtain the target transmission communication optical signal, and output the target transmission communication optical signal to the optical antenna array module.

2. The multi-target communication system as described in claim 1, characterized in that, The optical antenna array module includes an antenna array, which is distributed in the spatial elevation and azimuth directions. The distribution of the antenna array is not limited to circular arrays and square arrays.

3. The multi-target communication system as described in claim 2, characterized in that, The multi-target communication system further includes: a transceiver channel correction module; The transceiver channel correction module is connected to the optical antenna array module, the transmit channel link module, and the receive channel link module, respectively. The transceiver channel correction module is used to specify a frame header without service scheduling as a correction frame, insert the correction frame into the correction sequence of each channel of the transmit channel link module for channel correction, obtain the transmit channel correction received signal through the optical antenna array module coupling loopback, and output the transmit channel correction received signal to the transmit channel link module. The transceiver channel correction module is further configured to modulate the first branched optical signal output from the first laser with the correction frame to obtain a receiving channel correction transmission signal, and return it to the receiving channel link module through the coupling loop of the optical antenna array module to perform channel correction on each channel of the receiving channel link module.

4. The multi-target communication system as described in claim 3, characterized in that, The transceiver channel correction module is also used to designate a certain transmission channel of the transmission channel link module as the transmission reference channel, and to estimate the channel delay difference and channel amplitude phase difference of the other channels with reference to the transmission reference channel. The transceiver channel correction module is further configured to designate a certain receiving channel of the receiving channel link module as the receiving reference channel, and to estimate the channel delay difference and channel amplitude phase difference of the other channels with reference to the receiving reference channel.

5. The multi-target communication system as described in claim 4, characterized in that, The optical antenna array module is also used to capture the received communication target signal through spatial spectrum estimation and obtain the spatial position of the communication target signal; The optical antenna array module is also used to detect changes in the spatial position of the communication target signal based on the spatial position, and to obtain the tracking angle; The optical antenna array module is also used to align the communication target signal according to the spatial position and the tracking angle, so that the target transmits a communication optical signal pointing towards the target.

6. A multi-target communication method, characterized in that, The multi-target communication method is applied to a multi-target communication system, which includes an optical antenna array module, a transmit channel link module, and a receive channel link module. The optical antenna array module is connected to both the transmit channel link module and the receive channel link module; the method includes: The transmission channel link module converts multi-target transmission data into target transmission communication optical signals, and outputs the target transmission communication optical signals to the optical antenna array module; The optical antenna array module transmits communication optical signals from the target and receives communication target signals from the communication target space; The optical antenna array module captures and tracks the received communication target signal, obtains the target optical signal, and outputs the target optical signal to the receiving channel link module; The receiving channel link module converts the target optical signal into multi-target communication reception data; The receiving channel link module includes a first optical fiber splitter, a first laser, a mixer and photodetector array, a first analog-to-digital converter module, and a receiving data processing module. The mixer and photodetector array are respectively connected to the first optical fiber splitter, the optical antenna array module, and the first analog-to-digital converter module. The first laser is connected to the first optical fiber splitter, and the receiving data processing module is connected to the first analog-to-digital converter module. The receiving channel link module converts the target optical signal into multi-target communication received data, including: the first optical fiber splitter converts the light generated by the first laser into a first split optical signal and outputs the first split optical signal to the mixer and photodetector array; the mixer and photodetector array down-converts the first split optical signal and the target optical signal output by the optical antenna array module to obtain a down-converted electrical signal and outputs the down-converted electrical signal to the first analog-to-digital converter module; the first analog-to-digital converter module converts the down-converted electrical signal into a digital received signal; and the received data processing module converts the digital received signal into multi-target communication received data. The transmission channel link module includes a second optical fiber splitter, a second laser, a modulator array, a first digital-to-analog converter module, and a transmission data processing module. The modulator array is connected to the second optical fiber splitter, the optical antenna array module, and the first digital-to-analog converter module, respectively. The second laser is connected to the second optical fiber splitter, and the transmission data processing module is connected to the first digital-to-analog converter module. The transmission channel link module converts multi-target transmission data into target transmission communication optical signals and outputs the target transmission communication optical signals to the optical antenna array module. This includes: the transmission data processing module converting multi-target transmission data into transmission weighted data and outputting the transmission weighted data to the first digital-to-analog converter module; the first digital-to-analog converter module converting the transmission weighted data into analog transmission signals and outputting the analog transmission signals to the modulator array; the second fiber optic splitter converting the light generated by the second laser into a second split optical signal and outputting the second split optical signal to the modulator array; and the modulator array modulating the second split optical signal with the analog transmission signal to obtain the target transmission communication optical signal and outputting the target transmission communication optical signal to the optical antenna array module.

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