Acquisition tracking and multi-aperture spatial diversity reception method for space laser communication
The capture tracking and multi-aperture spatial diversity reception method addresses alignment and turbulence issues in free space optical communication by employing beam deflection and synchronization units to compensate for optical path and phase errors, enhancing signal stability and reducing bit errors.
Patent Information
- Application Number
- CN202410167758.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-06
- Publication Date
- 2024-12-27
- Estimated Expiration
- 2044-02-06
AI Technical Summary
Existing free space optical communication systems face challenges in achieving real-time capture and tracking of optical signals, synchronization of diversity signals in the time domain, and common phase synthesis due to alignment errors and atmospheric turbulence, leading to high bit error rates and communication interruptions.
A capture tracking and multi-aperture spatial diversity reception method is employed, utilizing beam deflection mechanisms and multi-aperture spatial diversity at both the transmitting and receiving ends, coupled with time domain synchronization and phase modulation units to compensate for optical path and phase errors, enabling efficient signal coupling and demodulation.
This method reduces bit error rates and improves communication availability by compensating for wavefront distortions caused by atmospheric turbulence, ensuring stable signal transmission through optical path and phase control.
Smart Images
Figure CN118249903B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of free space optical communication, and in particular to a capture tracking and multi-aperture space diversity receiving method for space laser communication. Background Art
[0002] Free space optical communication (FSOC) has the advantages of both optical fiber communication and microwave communication and has been widely studied in recent years. Compared with millimeter wave communication, FSOC has higher bandwidth and lower power consumption. Compared with optical fiber communication, high-bandwidth FSOC is not affected by the inter-symbol interference problem caused by the fiber dispersion effect.
[0003] When the signal light is transmitted in free space, it will be affected by the vibration of the platform and the atmospheric turbulence, resulting in alignment errors. At the same time, the signal light will also be affected by the atmospheric turbulence during transmission, resulting in wavefront distortion. These phenomena will cause random fluctuations in the received power, resulting in a high bit error rate in the free space optical communication system or even communication interruption. Currently, a large number of studies are focused on the common phase synthesis of diversity reception signals. However, from the perspective of multi-aperture spatial diversity reception, the premise for achieving high-availability space laser communication is the real-time capture and tracking of the optical signal transmitter and the optical signal receiver, the synchronization of the optical path of the diversity signal in the time domain, and the common phase synthesis of the diversity signal. Summary of the invention
[0004] In view of the deficiencies in the prior art, the present invention provides a capture tracking and multi-aperture spatial diversity reception method for space laser communication, so as to solve the technical problems in the prior art of how to achieve the capture tracking of signal light, the synchronization of the optical path of the diversity signal in the time domain and the common phase synthesis of the diversity signal.
[0005] The present invention provides a capture tracking and multi-aperture space diversity receiving method for space laser communication, comprising:
[0006] S1. A light beam deflection mechanism and a multi-aperture spatial diversity are respectively provided at an optical signal transmitting end and an optical signal receiving end. The optical signal transmitting end and the optical signal receiving end are captured and tracked by the light beam deflection mechanism, and initial alignment is achieved;
[0007] S2, the optical signal transmitting end transmits an optical signal, the multi-aperture spatial diversity receiving array of the optical signal receiving end receives the optical signal and performs aperture segmentation, and efficiently couples each segmented optical signal into the coupling optical fiber of the adaptive optical fiber coupler;
[0008] S3, the coupling optical fiber is correspondingly connected to a time domain synchronization unit, and the time domain synchronization unit adopts a control algorithm to adjust and compensate the optical path difference between each optical signal with the bit error rate as an evaluation index;
[0009] S4. The time domain synchronization unit is connected to a phase modulation unit. The phase modulation unit adopts a control algorithm to adjust and compensate the phase error between each optical signal based on the power of the synthetic light beam as the evaluation standard, and synthesizes all the optical signals of each channel into one signal through a cascaded 3dB coupler for demodulation.
[0010] Optionally, the capturing and tracking of the optical signal transmitting end and the optical signal receiving end by the light beam deflection mechanism includes:
[0011] The optical signal transmitting end transmits an optical signal and scans the uncertain area, and in the process of scanning the uncertain area, the optical signal receiving end detects the optical signal;
[0012] If after the scan is completed, the optical signal receiving end does not detect the optical signal or the signal-to-noise ratio of the optical signal detected by the receiving end cannot meet the preset capture and tracking conditions, it is determined that the capture has failed; otherwise, it is determined that the capture has been successful, and the optical signal transmitting end and the optical signal receiving end continue to track through the beam deflection mechanism.
[0013] Optionally, the initial alignment is achieved, comprising:
[0014] The optical signal transmitting end and the optical signal receiving end respectively adjust the beam deflection mechanism so that the horizontal direction and the upward direction of the optical signal transmitting end and the optical signal receiving end point to each other respectively, thereby achieving initial alignment.
[0015] Optionally, the beam deflection mechanism comprises:
[0016] Gimbal, rotating biprism, liquid crystal beam deflector, microlens array scanner or scanning galvanometer.
[0017] Optionally, the time domain synchronization unit includes:
[0018] Fiber optic delay line, variable fiber optic delay line, phase modulated fiber optic delay, refractive fiber optic delay or optical crystal delay.
[0019] Optionally, the phase modulation unit includes:
[0020] Acousto-optic phase modulator, electro-optic phase modulator, piezoelectric phase modulator, thermo-optic phase modulator or magneto-optic phase modulator.
[0021] Optionally, the control algorithm comprises:
[0022] Stochastic parallel gradient descent algorithm, dithering algorithm, PID algorithm or reinforcement learning algorithm.
[0023] Optionally, the output is a signal demodulation, including:
[0024] The output signal uses a demodulation method including but not limited to coherent demodulation and incoherent demodulation.
[0025] Compared with the prior art, the present invention has the following beneficial effects:
[0026] Both the optical signal transmitting end and the optical signal receiving end are equipped with a beam deflection mechanism to realize the capture and tracking of the signal light from the transmitting end to the receiving end. After the signal light is received by multiple aperture diversity and coupled into the coupling optical fiber, each diversity signal is connected to the time domain synchronization unit for optical path compensation, and then passes through the phase modulation unit for phase control compensation to achieve the common phase synthesis of multiple signals, and finally outputs one signal for demodulation to compensate and correct the wavefront distortion caused by atmospheric turbulence, reduce the bit error rate of the free space optical communication system, and improve availability. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.
[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.
[0029] Figure 1 It is a schematic diagram of the process of the present invention;
[0030] Figure 2 It is a structural schematic diagram of the optical signal transmitting end and the optical signal receiving end in the present invention;
[0031] Figure 3 It is a schematic diagram of the structure of the multi-aperture space diversity receiving device in the present invention;
[0032] Figure 4 A schematic diagram of synthesizing two-way diversity signals according to an embodiment of the present invention;
[0033] Figure 5 This is a schematic diagram of the change of the optical path difference synthesis power and bit error rate of 0-100ps in one embodiment of the present invention;
[0034] Figure 6This is a statistical diagram of the normalized received light intensity and bit error number of four-way signal synthesis according to an embodiment of the present invention.
[0035] Description of reference numerals:
[0036] 100, optical signal transmitting end; 101, laser driving module; 102, modulated laser; 103, signal light; 104, multi-aperture spatial diversity at transmitting end; 105, beam deflection mechanism at transmitting end; 200, optical signal receiving end; 201, photodetector; 202, beam deflection mechanism at receiving end; 203, multi-aperture spatial diversity at receiving end; 204, receiving sub-aperture; 205, multi-aperture spatial diversity receiving device. DETAILED DESCRIPTION
[0037] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The functional units with the same labels in the examples of the present invention have the same and similar structures and functions.
[0038] See also Figure 1 The present invention provides a capture tracking and multi-aperture spatial diversity receiving method for space laser communication, comprising:
[0039] S1. The optical signal transmitting end 100 and the optical signal receiving end 200 are respectively provided with a beam deflection mechanism and a multi-aperture spatial diversity, and the optical signal transmitting end 100 and the optical signal receiving end 200 are captured and tracked by the beam deflection mechanism, and initial alignment is achieved;
[0040] S2, the optical signal transmitting end 100 transmits an optical signal, the multi-aperture spatial diversity receiving array of the optical signal receiving end 200 receives the optical signal and performs aperture division, and efficiently couples each divided optical signal into the coupling optical fiber of the adaptive optical fiber coupler;
[0041] S3, the coupling optical fiber is correspondingly connected to a time domain synchronization unit, and the time domain synchronization unit adopts a control algorithm to adjust the optical path difference compensation of each optical signal with the bit error rate as an evaluation index;
[0042] S4. The time domain synchronization unit is correspondingly connected to a phase modulation unit. The phase modulation unit adopts a control algorithm to adjust and compensate the phase error of each optical signal based on the power of the synthetic light beam as the evaluation standard, and synthesizes all the optical signals of each channel into one signal through a cascaded 3dB coupler for demodulation.
[0043] In this embodiment, S1, the optical signal transmitting end 100 and the optical signal receiving end 200 are respectively provided with a beam deflection mechanism and a multi-aperture spatial diversity, wherein the optical signal transmitting end 100 can perform link calculation in advance, obtain a pre-transmitted power, and preliminarily configure the pulse frequency and duty cycle according to the pre-transmitted power. The transmitting end beam deflection mechanism 105 and the receiving end beam deflection mechanism 202 are adjusted so that the horizontal direction and the upward direction of the optical signal transmitting end 100 and the optical signal receiving end 200 are respectively pointed to each other to achieve initial alignment.
[0044] See also Figure 3 The optical signal transmitting end 100 at least includes a transmitting end multi-aperture spatial diversity 104, a transmitting end beam deflection mechanism 105 and an optical module. The signal light 103 can be generated by a 10Gbps 1550nm optical module (which can be adjusted based on the preliminary configuration). The optical signal transmitting end 100 and the optical signal receiving end 200 are both equipped with a beam deflection mechanism to realize the capture and tracking of the signal light 103 from the transmitting end to the receiving end, wherein the beam deflection mechanism includes but is not limited to a two-dimensional turntable, a universal mount, a rotating double prism, a liquid crystal beam deflector, a microlens array scanner and a scanning galvanometer. The light speed deflection unit adopts a control algorithm (including but not limited to a centroid algorithm) to realize the tracking and aiming of the optical signal from the optical signal transmitting end 100 to the optical signal receiving end 200 based on the off-target amount of the optical signal. In the design scheme of the multi-aperture spatial diversity 104, the sub-aperture spacing is less than the coherence length, the smaller the aperture of the sub-aperture, the stronger the anti-turbulence ability, and the sub-aperture arrangement can be triangular, honeycomb or circular.
[0045] Based on the current configuration, the laser driving module 101 in the optical signal transmitting end 100 is used to provide a pulse signal for the modulated laser 102 in the optical signal transmitting end 100, and the modulated laser 102 emits a signal light 103 and scans the uncertain area; in the process of scanning the uncertain area, the optical signal receiving end 200 detects the signal light 103. Preferably, the optical signal receiving end 200 can also be separately added with a sensor, such as a camera or a four-quadrant photoelectric detector to achieve detection and capture;
[0046] If after the scan is completed, the photodetector 201 in the optical signal receiving end 200 does not detect the signal light 103 or the signal-to-noise ratio of the signal light 103 detected by the receiving end cannot meet the preset capture and tracking conditions, it is determined that the capture has failed, and the duty cycle is reduced and the configuration is updated and the above steps are re-executed; otherwise, it is determined that the capture is successful, and after the capture is successful, the optical signal transmitting end 100 and the optical signal receiving end 200 continue to track through the beam deflection mechanism.
[0047] S2. The optical signal transmitting end 100 transmits an optical signal, and the multi-aperture spatial diversity receiving array of the optical signal receiving end 200 receives the optical signal and performs aperture segmentation, and efficiently couples each segmented optical signal into the coupling optical fiber of the adaptive optical fiber coupler.
[0048] See also Figure 2 The optical signal receiving end 200 at least includes a receiving end multi-aperture spatial diversity 203, a receiving end beam deflection mechanism 202, a multi-aperture spatial diversity receiving device 205 and a receiving sub-aperture 204. The number and arrangement of the receiving sub-apertures 204 in the multi-aperture spatial diversity receiving array are not unique and can be adjusted according to needs. The optical signal is aperture-split, and each optical signal after the split is efficiently coupled into the coupling optical fiber of the adaptive optical fiber coupler to achieve a multi-aperture spatial diversity receiving effect.
[0049] S3. The coupled optical fiber pair should be connected to a time domain synchronization unit, and the time domain synchronization unit adopts a control algorithm to adjust the bit error rate as an evaluation index to perform optical difference compensation on each optical signal.
[0050] A time domain synchronization unit is connected to each coupled optical fiber. The time domain synchronization unit adopts a control algorithm to adjust the optical path difference compensation of all optical signals in each channel with the bit error rate as the evaluation index. The control algorithm can be a random parallel gradient descent algorithm, a jitter algorithm, a PID algorithm or a reinforcement learning algorithm, etc. The time domain synchronization unit is not limited to a fiber delay line, a variable fiber delay line, a phase modulation fiber delay, a refractive fiber delay, an optical crystal delay, etc.
[0051] See also Figure 3 , the time domain synchronization unit is selected as an optical fiber delay line. During implementation, the optical path delay time of the time domain synchronization unit is first adjusted, and the adjustable delay range is 0-700ps. The optical path difference control algorithm transmits the bit error rate as a performance indicator to the controller. The controller uses an optimization algorithm to generate a control signal to drive the optical fiber delay line to achieve the control of the optical path difference between the two beams of light. When the bit error rate is 0, basic optical path difference synchronization is achieved between the two sub-beams. This patent explores the tolerance range of optical path time domain synchronization between diversity signals. For non-return-to-zero pulse signals, the maximum optical path difference allowed between signals is approximately 70% of the bit period length.
[0052] See also Figure 4, the test signal continues to be generated by the 10Gbps 1550nm optical module, and the 1×2 beam splitter is used to make the two signals transmitted independently to simulate the diversity reception signal. Then, the optical fiber delay line and the phase modulator are connected respectively for optical path difference correction and phase difference control, and then the 3dB optical fiber coupler is used to synthesize and output a signal for demodulation and connect to the bit error tester. In the experiment, the optical path delay time is first adjusted. When the instantaneous bit error rate is zero, the two sub-beams are basically synchronized. Since the phase in the optical fiber is affected by factors such as ambient temperature and devices, the slowly varying jitter causes the light intensity of the synthesized light beam to fluctuate, thereby generating a threshold effect. After applying common phase control through the phase modulator, a stable synthesized light beam can be output. The photodetector 201 is located at the end of the detection end, which is used to detect the synthetic light intensity and transmit the detected light intensity to the controller as a performance indicator. The controller uses an optimization algorithm to generate a control signal to drive the phase modulator to control the phase difference between the two beams so that it converges to the direction of maximum light intensity.
[0053] S4. The time domain synchronization unit is correspondingly connected to a phase modulation unit. The phase modulation unit adopts a control algorithm to adjust and compensate the phase error of each optical signal based on the power of the synthetic light beam as the evaluation standard, and synthesizes all the optical signals of each channel into one signal through a cascaded 3dB coupler for demodulation.
[0054] The phase modulation unit adopts a control algorithm to adjust and compensate the phase error of each optical signal with the power of the synthetic light beam as the evaluation standard, wherein the power of the synthetic light beam can be obtained by splitting the light through the back end to obtain a part of the performance index, or it can be obtained by filtering the signal demodulated by the phase modulation unit. The control algorithm can also be a random parallel gradient descent algorithm, a jitter algorithm, a PID algorithm or a reinforcement learning algorithm, etc. The phase modulation unit adjusts and compensates the phase error between all optical signals to make them coherently superimposed. The phase modulation unit can be an acousto-optic phase modulator, an electro-optic phase modulator, a piezoelectric phase modulator, a thermo-optic phase modulator or a magneto-optic phase modulator. Finally, all optical signals of each channel are synthesized and output as one signal through a 3dB coupler for demodulation. The final output synthetic light beam can use demodulation methods including but not limited to coherent demodulation and incoherent demodulation. If the phase modulation unit is implemented in the form of an integrated optical chip, it can also be an on-chip optical phased array.
[0055] See also Figure 3When implemented, the half-wave voltage of the phase modulator is about 2.2V, the output voltage range is -10V to 10V, and the phase control range is about 4 wavelengths, which meets the phase control requirements. The photodetector 201 is located at the end of the detection end, which is used to detect the synthetic light intensity and transmit the detected light intensity as a performance indicator to the controller. The controller uses an optimization algorithm to generate a control signal to drive the phase modulator to control the phase difference between the two beams of light so that it converges to the direction of maximum light intensity.
[0056] See also Figure 2 Based on the principle of optical fiber transmission, a two-way signal all-fiber transmission beam combining model was constructed in the OptiSystem software. The test signal is a 10Gbps pseudo-random sequence. The 1550nm laser is modulated as a carrier by a Mach-Zehnder modulator to generate a direct intensity modulation signal in NRZ format with a bit period of ps. In the simulation, the two signals are initially completely synchronized. After one signal is transmitted, it is directly connected to the coupler through optical fiber transmission. The other signal is combined after adding an optical path difference of 0 to ps. After being combined into one signal through the coupler, it is connected to the detector for demodulation and a bit error rate test is performed.
[0057] See also Figure 5 The simulation results show that when there is phase jitter, the optical synthesis output power fluctuates violently. At this time, the received signal strength may be lower than the detection sensitivity, resulting in a threshold effect and causing a large number of bit errors. The bit error rate has no obvious regularity. Figure 5 For the red curves of (a) and (b), when phase control is performed, the received signal is always stable at a high level, and the bit error rate increases with the increase of the delay time. At this time, the reason for the bit error is only the delay caused by the optical path difference, which has nothing to do with the intensity of the received signal light 103. It can be observed that for the optical synthesis of diversity signals, optical path difference correction and phase difference control must be performed simultaneously to achieve efficient and stable communication.
[0058] See also Figure 6 In order to explore whether the synchronization tolerance range is applicable to the synthesis of more diversity signals, the fiber delay line FDL was connected to perform fiber compensation, and then the phase modulator PM was used to perform phase control to conduct a 4-way synthesis experiment. With one signal as a reference, the fiber delay line was adjusted to synchronize other signals with it, and the optical path difference delay between any two signals was ensured not to exceed the delay caused by the maximum optical path difference. It can be seen that under the condition of simultaneous control of the optical path difference and the phase difference (FDL adjust+Phase control), the average bit error rate is 0. This result proves the feasibility of this scheme in the synthesis of more diversity signals.
[0059] The multi-aperture spatial diversity receiving technology of the present invention can obtain a higher diversity gain, solve the problem that the signal beam of the free space optical communication system is affected by atmospheric turbulence during space propagation, resulting in wavefront distortion and random fading of optical power, and has obvious advantages in satellite-to-ground laser communication, near-ground free space laser communication, underwater laser communication, and water-to-air cross-medium laser communication. At the same time, the multi-aperture spatial diversity receiving technology can effectively suppress the turbulence effect. The optical signal transmitting end 100 and the optical signal receiving end 200 are both equipped with a beam deflection mechanism to realize the capture and tracking of the signal light 103 from the transmitting end to the receiving end. After the signal light 103 is received by multiple aperture diversity and coupled into the coupling optical fiber, each diversity signal is respectively connected to the time domain synchronization unit for optical path compensation, and then the phase modulation unit is used for phase control compensation to realize the common phase synthesis of multiple signals, and finally a signal is output for demodulation to compensate and correct the wavefront distortion caused by atmospheric turbulence, reduce the bit error rate of the free space optical communication system, and improve the availability.
[0060] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.
[0061] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.
Claims
1. A capture tracking and multi-aperture spatial diversity receiving method for space laser communication, characterized in that: include: S1. A light beam deflection mechanism and a multi-aperture spatial diversity are respectively provided at an optical signal transmitting end and an optical signal receiving end. The optical signal transmitting end and the optical signal receiving end are captured and tracked by the light beam deflection mechanism, and initial alignment is achieved; S2, the optical signal transmitting end transmits an optical signal, the multi-aperture spatial diversity receiving array of the optical signal receiving end receives the optical signal and performs aperture segmentation, and efficiently couples each segmented optical signal into the coupling optical fiber of the adaptive optical fiber coupler; S3, the coupling optical fiber is correspondingly connected to a time domain synchronization unit, and the time domain synchronization unit adopts a control algorithm to adjust the optical path difference compensation of each optical signal with the bit error rate as an evaluation index; S4. The time domain synchronization unit is correspondingly connected to a phase modulation unit. The phase modulation unit adopts a control algorithm to adjust and compensate the phase error of each optical signal based on the power of the synthetic light beam as the evaluation standard, and synthesizes all the optical signals of each channel into one signal through a cascaded 3dB coupler for demodulation.
2. The capture tracking and multi-aperture spatial diversity receiving method for space laser communication according to claim 1, characterized in that: The capture and tracking of the optical signal transmitting end and the optical signal receiving end by the optical beam deflection mechanism includes: The optical signal transmitting end transmits an optical signal and scans the uncertain area, and in the process of scanning the uncertain area, the optical signal receiving end detects the optical signal; If after the scan is completed, the optical signal receiving end does not detect the optical signal or the signal-to-noise ratio of the optical signal detected by the receiving end cannot meet the preset capture and tracking conditions, it is determined that the capture has failed; otherwise, it is determined that the capture has been successful, and the optical signal transmitting end and the optical signal receiving end continue to track through the beam deflection mechanism.
3. The capture tracking and multi-aperture spatial diversity receiving method for space laser communication according to claim 2, characterized in that: Described and achieve initial alignment, including: The optical signal transmitting end and the optical signal receiving end respectively adjust the beam deflection mechanism so that the horizontal direction and the upward direction of the optical signal transmitting end and the optical signal receiving end point to each other respectively, thereby achieving initial alignment.
4. The capture tracking and multi-aperture spatial diversity receiving method for space laser communication according to claim 1, characterized in that: The beam deflection mechanism comprises: Gimbal, rotating biprism, liquid crystal beam deflector, microlens array scanner or scanning galvanometer.
5. The capture tracking and multi-aperture spatial diversity receiving method for space laser communication according to claim 1, characterized in that: The time domain synchronization unit comprises: Fiber optic delay line, variable fiber optic delay line, phase modulated fiber optic delay, refractive fiber optic delay or optical crystal delay.
6. The capture tracking and multi-aperture spatial diversity receiving method for space laser communication according to claim 1, characterized in that: The phase modulation unit comprises: Acousto-optic phase modulator, electro-optic phase modulator, piezoelectric phase modulator, thermo-optic phase modulator or magneto-optic phase modulator.
7. The capture tracking and multi-aperture spatial diversity receiving method for space laser communication according to claim 1, characterized in that: The control algorithm comprises: Stochastic parallel gradient descent algorithm, dithering algorithm, PID algorithm or reinforcement learning algorithm.
8. The capture tracking and multi-aperture spatial diversity receiving method for space laser communication according to claim 1, characterized in that: The output is a signal demodulation, including: The output signal uses a demodulation method including but not limited to coherent demodulation and incoherent demodulation.