A system and method for testing the effects of atmospheric turbulence on a laser communication device

Abstract

The application provides a system for testing the influence of atmospheric turbulence on a laser communication device, comprising: an information generation module, a digital-to-analog conversion module, a modulation module, an optical power amplification module, a detector module and an analysis module; the information generation module is used for simulating a digital communication signal affected by atmospheric turbulence; the digital-to-analog conversion module is used for converting the digital communication signal affected by atmospheric turbulence into an analog signal; the modulation module is used for generating a laser communication signal based on the analog signal; the optical power amplification module is used for amplifying the energy of the laser communication signal; the detector module is used for quantizing the amplified laser communication signal after transmission; and the analysis module is used for analyzing the quantized laser communication receiving signal to generate an analysis result. Digitizing the turbulence disturbance signal and directly applying it to the digital baseband signal is a processing mode for the laser communication terminal, and has the characteristics of simplicity and convenience.

Description

Technical Field

[0001] This invention relates to the field of laser communication technology, and more specifically to a system and method for testing the effects of atmospheric turbulence on laser communication devices. Background Technology

[0002] Compared to traditional microwave communication, laser communication boasts advantages such as high bandwidth, small beam divergence angle, and resistance to electromagnetic interference. Due to its higher transmission rate and better communication security, laser communication plays a crucial role in future integrated air-space-ground networks. However, in atmospheric laser communication systems, turbulence disturbances in the channel hinder the achievement of long-distance and high-speed requirements. Therefore, further research into turbulence phenomena is needed to improve the channel model of laser communication systems. The most prominent characteristic of turbulence is its irregularity: 1. Irregular fluctuations in the time series of flow physical quantities; 2. Irregular spatial distribution; 3. Non-repeatability of actual flow data under any two identical conditions. Although turbulence exhibits irregularity, extensive experiments have shown that, statistically, the turbulent velocity field has a regular probability distribution. Generally, weak turbulence models are considered to follow a log-normal distribution. Traditional atmospheric turbulence simulation devices typically generate atmospheric turbulence by heating the atmosphere and forcing convection. During experiments, the heating power is controlled by inputting simulated atmospheric channel parameters to achieve the required temperature difference and obtain the experimental atmospheric turbulence conditions. However, as can be seen from its structural characteristics, the atmospheric turbulence pool experimental device is huge and has a large number of experimental simulation parameters.

[0003] The above-mentioned problems urgently need to be solved. Summary of the Invention

[0004] This invention aims to overcome at least one of the aforementioned drawbacks of the prior art. On one hand, it provides a system for testing the impact of atmospheric turbulence on a laser communication device. The system includes: an information generation module, a digital-to-analog conversion module, a modulation module, an optical power amplification module, a detector module, and an analysis module. The output of the information generation module is connected to the input of the digital-to-analog conversion module, used to simulate a digital communication signal affected by atmospheric turbulence. The output of the digital-to-analog conversion module is connected to the input of the modulation module, used to convert the digital communication signal affected by atmospheric turbulence into an analog signal. The output of the modulation module is connected to the input of the optical power amplification module, used to generate a laser communication signal based on the analog signal. The output of the optical power amplification module is connected to the input of the detector module, used to amplify the energy of the laser communication signal and transmit it to the detector module. The output of the detector module is connected to the input of the analysis module, used to receive, amplify, and perform analog-to-digital conversion on the amplified laser communication signal after transmission. The analysis module is used to analyze the quantized laser communication received signal and generate analysis results.

[0005] Preferably, the information generation module further includes a turbulence disturbance signal generation module and a high-speed baseband signal generation module; the turbulence disturbance signal generation module is used to simulate weak turbulence disturbance signals in the atmospheric channel; the high-speed baseband signal generation module is used to generate high-speed baseband signals.

[0006] Preferably, the information generation module is further configured to directly apply the weak turbulence disturbance signal to the high-speed baseband signal to simulate the digital communication signal affected by atmospheric turbulence.

[0007] Preferably, the module for generating turbulence disturbance signals is also used to generate weak turbulence disturbance signals in a simulated atmospheric channel using the Monte Carlo method.

[0008] Preferably, the modulation module is further configured to modulate the laser source input to the laser based on the analog signal to generate a laser communication signal.

[0009] Preferably, a transmitting optical antenna module is further connected after the optical power amplification module; the input end of the transmitting optical antenna module is connected to the output end of the optical power amplification module, and the output end of the transmitting optical antenna module is connected to the input end of the receiving optical antenna module; the transmitting optical antenna module is used to convert the received amplified laser communication signal into a spatial optical signal.

[0010] Preferably, the optical power amplification module is also used to transmit the amplified laser communication signal to the transmitting optical antenna module.

[0011] Preferably, the optical power amplification module is also used to directly transmit the amplified laser communication signal to the detector module.

[0012] Preferably, the output of the transmitting optical antenna module is further connected to a receiving optical antenna module, and the output of the receiving optical antenna module is connected to the input of the detector module for focusing the received spatial beam. The detector module includes a detector, a transimpedance amplifier, and an analog-to-digital converter. The detector is used to convert the optical signal into a photocurrent signal. The transimpedance amplifier is used to convert the photocurrent signal into an amplified voltage signal. The analog-to-digital converter is used to convert the amplified analog voltage signal into a digital signal. The analysis module includes a demodulator, a data output module, a bit error rate calculation module, an energy harvesting circuit, a turbulence calculation module, and an analysis sub-module. The system comprises the following modules: a demodulator for demodulating the received laser communication signal to obtain a baseband signal; a data output module for inputting the demodulated baseband signal into a bit error rate calculation module; a bit error rate calculation module for calculating the bit error rate of the communication device; an energy acquisition circuit for measuring the amplitude of the output electrical signal and calculating the light energy received by the detector; a turbulence calculation module for calculating the current atmospheric turbulence scintillation index by statistically analyzing the fluctuations in received energy; and an analysis submodule for analyzing the jitter of the communication light intensity and communication performance of the laser communication device under different turbulent channels based on the atmospheric turbulence scintillation index and the bit error rate of the laser communication device.

[0013] On the other hand, the present invention provides a method for testing the impact of atmospheric turbulence on a laser communication device. The method includes: simulating a digital communication signal affected by atmospheric turbulence using an information generation module; converting the digital communication signal into an analog signal by digital-to-analog conversion; controlling a modulator to generate a laser communication signal based on the analog signal; amplifying the laser communication signal using an optical power amplifier; converting the received amplified laser communication signal into a space optical signal using a transmitting optical antenna module on a space optical link; focusing the received beam onto a detector module using a receiving optical antenna module; transmitting the amplified laser communication signal transmitted by the optical power amplifier module to the detector module via an optical fiber on an optical fiber link; receiving, amplifying, and performing analog-to-digital conversion on the transmitted amplified laser communication signal using the detector module; calculating the scintillation index and bit error rate of the laser communication signal output by the detector module; and generating analysis results based on the scintillation index and bit error rate of the laser communication signal.

[0014] In another aspect, the present invention also provides a computer-readable storage medium storing one or more instructions for causing a computer to perform the above-described method for testing the effects of atmospheric turbulence on a laser communication device.

[0015] In another aspect, the present invention provides an electronic device, comprising: a memory and a processor; the memory storing at least one program instruction; the processor loading and executing the at least one program instruction to implement the above-described method for testing the effect of atmospheric turbulence on a laser communication device.

[0016] The beneficial effects of this invention are as follows: This invention provides a system for testing the impact of atmospheric turbulence on laser communication devices. The system includes: an information generation module, a digital-to-analog conversion module, a modulation module, an optical power amplification module, a detector module, and an analysis module. The information generation module is used to simulate digital communication signals affected by atmospheric turbulence. The digital-to-analog conversion module is used to convert the digital communication signals affected by atmospheric turbulence into analog signals. The modulation module is used to generate laser communication signals based on the analog signals. The optical power amplification module is used to amplify the energy of the laser communication signals and transmit them to the detector module. The detector module is used to receive, amplify, and perform analog-to-digital conversion on the amplified laser communication signals after transmission. The analysis module is used to analyze the quantized laser communication received signals and generate analysis results. Digitizing the turbulence disturbance signal and directly applying it to the digital baseband signal is a processing method for laser communication terminals, which is simple and convenient. Furthermore, this invention generates random variables based on the given scintillation variance of the turbulence, which allows for a more intuitive observation of light intensity jitter and communication performance under different turbulence orders of magnitude. Meanwhile, since the probability distribution of weak turbulence disturbances in both underwater and atmospheric channels follows a log-normal distribution, this invention has universal applicability to both atmospheric and underwater turbulence channels. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Figure 1 This is a system structure diagram of an embodiment of the present invention for testing the effect of atmospheric turbulence on a laser communication device.

[0019] Figure 2 This is a schematic diagram of the structure of the analysis module provided in an embodiment of the present invention.

[0020] Figure 3 This is a schematic diagram of light intensity distribution provided in an embodiment of the present invention.

[0021] Figure 4 The embodiments of the present invention are based on Figure 3 A schematic diagram of the light intensity distribution and a probability distribution curve.

[0022] Figure 5 This is a flowchart of a method for testing the effect of atmospheric turbulence on laser communication devices provided in an embodiment of the present invention.

[0023] Figure 6 This is a partial block diagram of the electronic device provided in the embodiments of the present invention.

[0024] The attached figures are labeled as follows:

[0025] Information generation module-1; Digital-to-analog conversion module-2; Modulation module-3; Optical power amplification module-4; Analysis module-5; Turbulence disturbance signal generation module-101; High-speed baseband signal generation module-102; Transmitting optical antenna module-6; Receiving optical antenna module-7; Detector module-8; Demodulator-503; Data output module-504; Bit error rate calculation module-505; Energy harvesting circuit-506; Turbulence calculation module-507; Analysis submodule-508. Detailed Implementation

[0026] Before discussing the exemplary embodiments in more detail, it should be noted that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe the operations as sequential processes, many of these operations can be performed in parallel, concurrently, or simultaneously. Furthermore, the order of the operations can be rearranged. The process can be terminated when its operation is completed, but may also have additional steps not included in the figures. The process can correspond to a method, function, procedure, subroutine, subroutine, etc.

[0027] It should be understood that although the terms "first," "second," etc., may be used herein to describe various units, these units should not be limited by these terms. These terms are used merely to distinguish one unit from another. For example, without departing from the scope of the exemplary embodiments, a first unit may be referred to as a second unit, and similarly, a second unit may be referred to as a first unit. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0028] The present invention will now be described in detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0029] For ease of understanding, the technical terms that may appear in the embodiments are explained here:

[0030] The Monte Carlo method, also known as the statistical simulation method, is a very important numerical computation method guided by probability and statistics theory. It was proposed in the mid-1940s due to advancements in science and technology and the invention of electronic computers. It refers to the use of random numbers (or more commonly, pseudo-random numbers) to solve many computational problems.

[0031] DAC (Digital to Analog Converter) is a device that converts digital signals into analog signals (in the form of current, voltage, or charge). In many digital systems (such as computers), signals are stored and transmitted digitally, and DACs can convert such signals into analog signals, making them recognizable by external systems (humans or other non-digital systems).

[0032] Example 1

[0033] Please see Figure 1 The present invention provides a schematic diagram of a system structure for testing the effect of atmospheric turbulence on laser communication devices.

[0034] For ease of subsequent understanding, the overall inventive concept of this invention is described here:

[0035] The information generation module generates a high-speed baseband signal and a weak turbulence disturbance signal (i.e., a random variable following a log-normal distribution) generated from a simulated atmospheric channel using the Monte Carlo method. The signal fading caused by turbulence has a multiplicative effect on the transmitted signal. The simulated communication signal affected by atmospheric turbulence is converted into an analog signal by a DAC to control a modulator to generate a laser communication signal. The laser output signal is connected to an optical power amplifier via optical fiber. The optical power amplifier amplifies the laser communication signal energy and transmits it directly to the detector module via the optical fiber link. The detector module then processes the signal before transmitting it to the analysis module. Alternatively, on the space optical link, the amplified laser communication signal generated by the optical power amplifier module is first transmitted to the transmitting optical antenna module, then via the space optical link to the receiving optical antenna module for convergence to the detector module. The detector module processes the signal before transmitting it to the analysis module. The analysis module analyzes the received laser communication signal to test the jitter of the communication light intensity and the communication performance of the laser communication system under different turbulent channels. This provides a new approach for studying the impact of turbulence on laser communication systems and conducting turbulence suppression experiments.

[0036] The specific implementation method is as follows:

[0037] As an example, the system includes an information generation module 1, a digital-to-analog conversion module 2, a modulation module 3, an optical power amplification module 4, a detector module 8, and an analysis module 5. The output of the information generation module 1 is connected to the input of the digital-to-analog conversion module 2, and is used to simulate digital communication signals affected by atmospheric turbulence. The output of the digital-to-analog conversion module 2 is connected to the input of the modulation module 3, and is used to convert the digital communication signals affected by atmospheric turbulence into analog signals. The output of the modulation module 3 is connected to the input of the optical power amplification module 4, and is used to generate laser communication signals based on the analog signals. The output of the optical power amplification module 4 is connected to the input of the detector module 8, and is used to amplify the energy of the laser communication signals and transmit them to the detector module 8 through optical fiber. The output of the detector module 8 is connected to the input of the analysis module 5, and is used to receive, amplify, and perform analog-to-digital conversion on the amplified laser communication signals after transmission. The analysis module 5 is used to analyze the quantized laser communication received signals and generate analysis results.

[0038] Optionally, the information generation module 1 further includes a turbulence disturbance signal generation module 101 and a high-speed baseband signal generation module 102; the turbulence disturbance signal generation module 101 is used to simulate weak turbulence disturbance signals in the atmospheric channel; the high-speed baseband signal generation module 102 is used to generate high-speed baseband signals.

[0039] Optionally, the information generation module 1 is further used to directly apply the weak turbulence disturbance signal to the high-speed baseband signal to simulate the digital communication signal affected by atmospheric turbulence. This processing method for laser communication terminals is simpler and more convenient than the traditional method of generating atmospheric turbulence by heating the atmosphere and forcing convection. The signal fading effect caused by turbulence disturbance has a multiplicative effect on the transmitted signal; that is, the fading effect of the turbulence signal is considered constant over a period of time, during which many bits of communication signal may have been transmitted. More specifically, the multiplicative effect is as follows: assuming a non-return-to-zero (NRZ) OOK modulation direct modulation, amplitude probe (IM / DD) FSO link on the turbulence channel. When performing digital signal processing at the transmitting end of the communication system, the emitted light intensity corresponding to the k-th data transmission interval, i.e., [(k-1)T b ,kT b ], T b The duration of data transmission can be written as:

[0040] r k =hs k

[0041] Where h represents the fading coefficient of the signal caused by turbulence (corresponding to the digital communication signal described in this application), and is assumed to be constant over a large number of transmitted bits; s k This indicates that it has the power P to transmit optical power. t The transmitted data (corresponding to the digital baseband signal transmitted in this application).

[0042] Optionally, the turbulence disturbance signal generation module 101 is further configured to generate weak turbulence disturbance signals in a simulated atmospheric channel using the Monte Carlo method. That is, the weak turbulence disturbance is represented in digital signal form using the Monte Carlo method. This ensures that the digital signal output by the information generation module 1 follows a log-normal distribution, giving the originally irregular turbulence distribution a regular probability distribution, facilitating subsequent research on the impact of turbulence on the laser communication system.

[0043] Optionally, the digital-to-analog conversion module 2 is equipped with a DAC converter. Since the digital signal generated by the information generation module 1 cannot be directly read, it is converted into an analog signal by the DAC converter for subsequent reading.

[0044] Optionally, the modulation module 3 is further configured to modulate the laser source input to the laser based on the analog signal to generate a laser communication signal. Specifically, the modulation module 3 contains an electro-optic modulator that controls the laser source based on the received analog signal output from the DAC converter to generate the laser communication signal.

[0045] Optionally, a transmitting optical antenna module 6 is further connected after the optical power amplifier module 4; the input terminal of the transmitting optical antenna module 6 is connected to the output terminal of the optical power amplifier module 4, and the output terminal of the transmitting optical antenna module 6 is connected to the input terminal of the receiving optical antenna module 7; the transmitting optical antenna module 6 is used to convert the received amplified laser communication signal into a spatial optical signal. Further, the optical power amplifier module 4 is also used to transmit the amplified laser communication signal to the transmitting optical antenna module 6 through an optical fiber circulator.

[0046] Optionally, the optical power amplification module 4 is also used to amplify the laser communication signal and transmit it to the analysis module 5 via optical fiber. That is, the amplified laser communication signal can be transmitted to the analysis module in two ways: first, the amplified laser communication signal is directly transmitted to the detector module 8 via optical fiber, where the detector module 8 receives, amplifies, and performs analog-to-digital conversion on the received laser communication signal before transmitting it to the analysis module 5; second, the amplified laser communication signal is first transmitted to the transmitting optical antenna module 6, and then the receiving optical antenna module 7 focuses the beam onto the detector module 8 for receiving, amplification, and analog-to-digital conversion before transmitting it to the analysis module 5 for subsequent analysis. The detector module 8 includes a detector, a transimpedance amplifier, and an analog-to-digital converter. The detector converts the optical signal into a photocurrent signal, the transimpedance amplifier converts the photocurrent signal into an amplified voltage signal, and the analog-to-digital converter converts the amplified analog voltage signal into a digital signal.

[0047] Optional, such as Figure 2The diagram shows the structure of the analysis module. The analysis module 5 is also used to analyze the jitter of the communication light intensity and communication performance of the laser communication device under different turbulent channels based on the scintillation index of atmospheric turbulence and the bit error rate of the laser communication device. The analysis module 5 includes a demodulator 503, a data output module 504, a bit error rate calculation module 505, an energy acquisition circuit 506, a turbulence calculation module 507, and an analysis submodule 508. The demodulator 503 is used to demodulate the laser communication received signal to obtain the baseband signal. The data output module 504 is used to input the demodulated baseband signal to the bit error rate calculation module 505, which is used to calculate the bit error rate of the communication device. The energy acquisition circuit 506 is used to measure the amplitude of the output electrical signal and calculate the light energy received by the detector. The turbulence calculation module 507 is used to calculate the current atmospheric turbulence scintillation index by statistically analyzing the fluctuations of the received energy. The analysis submodule 508 is used to analyze the jitter of the communication light intensity and the communication performance of the laser communication device under different turbulence channels based on the scintillation index of atmospheric turbulence and the bit error rate of the laser communication device. Specifically, after the emitted beam passes through the atmospheric turbulence channel, it is focused by the receiving optical antenna module 7 into an optical fiber, which then connects to the detector module 8. The detector module 8 converts the optical signal into an electrical signal. The electrical signal output from the detector module 8 enters the energy harvesting circuit 506 and the demodulator 503, respectively. The demodulator 503 demodulates the communication data, and the energy harvesting circuit 506 measures the amplitude of the output electrical signal. Based on the photoelectric conversion efficiency and circuit amplification factor of the detector module 8, the light energy received by the detector module 8 at this time is calculated. The energy value output in real time by the energy harvesting circuit 506 is calculated by the turbulence calculation module 507. By statistically analyzing the fluctuations of the received energy, a light intensity distribution map is obtained, and the light intensity is then calculated according to the formula... Calculate the flicker index, where the flicker index σ I 2The definition of is the variance of the normalized light intensity of the light wave, where I is the light intensity and <> is the averaging operator. This is equivalent to calculating the atmospheric turbulence scintillation index at the time of channel turbulence. Simultaneously, the electrical signal output by detector module 8 is demodulated and output by demodulator 503, achieving stable reception of light energy without affecting the communication link. The bit error rate is calculated; the laser communication signal undergoes ADC quantization, threshold decision, and filtering to obtain the baseband signal, and the bit error rate of the communication device is calculated. The method for calculating the bit error rate is already very mature in existing technology and will not be elaborated further here. Finally, by analyzing the scintillation index calculated by submodule 508 based on turbulence calculation module 507 and the bit error rate calculated by bit error rate calculation module 505, the jitter of the communication light intensity and the communication performance of the laser communication system under different turbulent channels are tested. This provides a new scheme for studying the impact of turbulence on laser communication systems and conducting turbulence suppression experiments.

[0048] Optional, such as Figure 3 As shown, a schematic diagram of light intensity distribution is presented. The horizontal axis represents the acquisition time, and the vertical axis represents the conversion of the light intensity received by the detector into current (the light signal is converted into an electrical signal, and the light intensity is calculated based on this current value and the detector's responsivity). The fluctuations in light intensity can be observed through the light intensity distribution curve. Figure 4 As shown, it illustrates the basis Figure 3 The diagram illustrates the probability distribution curve of the light intensity distribution. The horizontal axis represents the conversion of the light intensity received by the detector into current, and the vertical axis represents the number of corresponding current intensities. Figure 4 The diagram shows the distribution of light intensity, with the highest peak indicating that the light power is concentrated around this value. It also shows that the signal under weak turbulence follows a log-normal distribution.

[0049] As described in the above embodiments, this invention digitizes turbulence disturbance signals and directly applies them to digital baseband signals through communication signal processing. This is a processing method for laser communication terminals, characterized by its simplicity and convenience. Furthermore, this invention generates random variables based on the given scintillation variance of the turbulence, allowing for a more intuitive observation of light intensity jitter and communication performance under different turbulence orders of magnitude. Simultaneously, since the probability distribution of weak turbulence disturbances in both underwater and atmospheric channels follows a log-normal distribution, this invention has universal applicability to both atmospheric and underwater turbulent channels.

[0050] Example 2

[0051] Please see Figure 5 This embodiment provides a flowchart of a method for testing the impact of atmospheric turbulence on laser communication devices, the method comprising:

[0052] S510: Simulates digital communication signals affected by atmospheric turbulence through the information generation module.

[0053] S520: Convert the digital communication signal into an analog signal by performing digital-to-analog conversion.

[0054] S530: Based on the analog signal, control the modulator to generate a laser communication signal.

[0055] S540: The laser communication signal energy is amplified by an optical power amplifier.

[0056] S550: On the space optical link, the received amplified laser communication signal is converted into a space optical signal by the transmitting optical antenna module, and the received beam is focused to the detector module by the receiving optical antenna module.

[0057] S560: On the fiber optic link, the detector module receives, amplifies, and performs analog-to-digital conversion on the amplified laser communication signal transmitted by the optical power amplifier module.

[0058] S570: Calculates the scintillation index and bit error rate of the laser communication signal output by the detector module.

[0059] S580: Generate analysis results based on the scintillation index and bit error rate of the laser communication signal.

[0060] Example 3

[0061] This invention also proposes a storage medium storing a method for testing the impact of atmospheric turbulence on a laser communication device. When the test program for the impact of atmospheric turbulence on the laser communication device is executed by a processor, it implements the steps described above for testing the impact of atmospheric turbulence on the laser communication device. Since this storage medium employs all the technical solutions of the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated upon further here.

[0062] Example 4

[0063] Please see Figure 6 The present invention also provides an electronic device, including: a memory and a processor; the memory stores at least one program instruction; the processor loads and executes the at least one program instruction to implement the method provided in Embodiment 2 for testing the effect of atmospheric turbulence on a laser communication device.

[0064] The memory 602 and processor 601 are connected via a bus, which may include any number of interconnecting buses and bridges, connecting various circuits of one or more processors 601 and memory 602 together. The bus may also connect various other circuits, such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. A bus interface provides an interface between the bus and the transceiver. The transceiver may be a single element or multiple elements, such as multiple receivers and transmitters, providing a unit for communicating with various other devices over a transmission medium. Data processed by processor 601 is transmitted over a wireless medium via an antenna, which further receives data and transmits it to processor 601.

[0065] Processor 601 is responsible for managing the bus and general processing, and can also provide various functions, including timing, peripheral interfaces, voltage regulation, power management, and other control functions. Memory 602 can be used to store data used by processor 601 during operation.

[0066] The above descriptions are merely embodiments of the present invention. Commonly known structures and characteristics are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, based on the guidance provided in this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A system for testing the effects of atmospheric turbulence on laser communication devices, characterized in that, The system includes: an information generation module, a digital-to-analog conversion module, a modulation module, an optical power amplification module, a detector module, and an analysis module; The output of the information generation module is connected to the input of the digital-to-analog conversion module, and is used to simulate digital communication signals affected by atmospheric turbulence. The output of the digital-to-analog converter module is connected to the input of the modulation module, and is used to convert the digital communication signal affected by atmospheric turbulence into an analog signal. The output of the modulation module is connected to the input of the optical power amplifier module, and is used to generate a laser communication signal based on the analog signal; The output of the optical power amplifier module is connected to the input of the detector module, and is used to amplify the energy of the laser communication signal and transmit it to the detector module through optical fiber; The output of the detector module is connected to the input of the analysis module, and is used to receive, amplify, and perform analog-to-digital conversion on the transmitted amplified laser communication signal. The analysis module is used to analyze the quantized laser communication received signal and generate analysis results. The information generation module also includes a turbulence disturbance signal generation module and a high-speed baseband signal generation module; The module for generating turbulence disturbance signals is used to simulate weak turbulence disturbance signals in atmospheric channels. The high-speed baseband signal generation module is used to generate high-speed baseband signals; The information generation module is also used to directly apply the weak turbulence disturbance signal to the high-speed baseband signal to simulate the digital communication signal affected by atmospheric turbulence; the signal fading caused by turbulence disturbance has a multiplicative effect on the transmitted signal. The module for generating turbulence disturbance signals is also used to generate weak turbulence disturbance signals in a simulated atmospheric channel using the Monte Carlo method. The weak turbulence disturbance is represented in the form of a digital signal using the Monte Carlo method. The digital signal output by the information generation module follows a log-normal distribution of random variables, so that the originally irregular turbulence distribution has a regular probability distribution.

2. The system for testing the effect of atmospheric turbulence on laser communication devices according to claim 1, characterized in that, The modulation module is also used to modulate the laser source input to the laser based on the analog signal to generate a laser communication signal.

3. The system for testing the effect of atmospheric turbulence on laser communication devices according to claim 1, characterized in that, The optical power amplifier module is also connected to a transmitting optical antenna module. The input terminal of the transmitting optical antenna module is connected to the output terminal of the optical power amplifier module, and the output terminal of the transmitting optical antenna module is connected to the input terminal of the receiving optical antenna module. The transmitting optical antenna module is used to convert the received amplified laser communication signal into a spatial optical signal.

4. The system for testing the effect of atmospheric turbulence on laser communication devices according to claim 3, characterized in that, The optical power amplification module is also used to transmit the amplified laser communication signal to the transmitting optical antenna module.

5. The system for testing the effect of atmospheric turbulence on laser communication devices according to claim 1, characterized in that, The optical power amplification module is also used to directly transmit the amplified laser communication signal to the detector module via optical fiber.

6. The system for testing the effect of atmospheric turbulence on laser communication devices according to claim 3, characterized in that, The output of the transmitting optical antenna module is also connected to a receiving optical antenna module, and the output of the receiving optical antenna module is connected to the input of the detector module for focusing the received space beam. The detector module includes a detector, a transimpedance amplifier, and an analog-to-digital converter; The detector is used to convert optical signals into photocurrent signals; The transimpedance amplifier is used to convert the photocurrent signal into an amplified voltage signal; The analog-to-digital converter is used to convert the amplified analog voltage signal into a digital signal; The analysis module includes: a demodulator, a data output module, a bit error rate calculation module, an energy harvesting circuit, a turbulence calculation module, and an analysis submodule; The demodulator is used to demodulate the laser communication received signal to obtain the baseband signal; The data output module is used to input the demodulated baseband signal into the bit error rate calculation module; The bit error rate calculation module is used to calculate the bit error rate of the communication device; The energy harvesting circuit is used to measure the amplitude of the output electrical signal and calculate the light energy received by the detector. The turbulence calculation module is used to calculate the current atmospheric turbulence scintillation index by statistically analyzing the fluctuations in received energy. The analysis submodule is used to analyze the jitter of the communication light intensity and communication performance of the laser communication device under different turbulent channels based on the scintillation index of atmospheric turbulence and the bit error rate of the laser communication device.

7. A method for testing the effect of atmospheric turbulence on laser communication devices, characterized in that, The method includes: The information generation module simulates digital communication signals affected by atmospheric turbulence. This module further includes a turbulence disturbance signal generation module and a high-speed baseband signal generation module. The turbulence disturbance signal generation module simulates weak turbulence disturbance signals in the atmospheric channel. The high-speed baseband signal generation module generates a high-speed baseband signal. The information generation module also directly applies the weak turbulence disturbance signal to the high-speed baseband signal to simulate the digital communication signal affected by atmospheric turbulence. The signal fading caused by turbulence disturbance has a multiplicative effect on the transmitted signal. Furthermore, the turbulence disturbance signal generation module uses the Monte Carlo method to generate simulated weak turbulence disturbance signals in the atmospheric channel. The Monte Carlo method represents the weak turbulence disturbance in the form of a digital signal. The digital signal output by the information generation module follows a log-normal distribution, making the originally irregular turbulence distribution have a regular probability distribution. The digital communication signal is converted from digital to analog to generate an analog signal; The analog signal controls the modulator to generate laser communication signals. The laser communication signal energy is amplified by an optical power amplifier; On the space optical link, the received amplified laser communication signal is converted into a space optical signal by the transmitting optical antenna module, and the received beam is focused to the detector module by the receiving optical antenna module. On the fiber optic link, the detector module receives, amplifies, and performs analog-to-digital conversion on the amplified laser communication signal transmitted by the optical power amplifier module; The scintillation index and bit error rate of the laser communication signal are calculated from the laser communication signal output by the detector module. Analysis results are generated based on the scintillation index and bit error rate of the laser communication signal.

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