Free space optical communication unmanned aerial vehicle auxiliary interference suppression method and device

Abstract

The invention provides a free space optical communication unmanned aerial vehicle auxiliary interference suppression method and device, relates to the technical field of wireless communication, is applied to a free space optical communication system, the system comprises a transmitter, an IRS, a receiver and an unmanned aerial vehicle auxiliary interference source, and the method comprises the following steps: obtaining an average bit error rate of the free space optical communication system; obtaining a distance parameter, wherein the distance parameter represents the position relationship between the RIS and the transmitter; and according to the average bit error rate, adjusting a distance parameter so as to alleviate the influence of the auxiliary interference of the unmanned aerial vehicle and realize the auxiliary interference suppression of the unmanned aerial vehicle. According to the method, the system model is established and is matched with technical means such as probability density function derivation, system performance analysis and unmanned aerial vehicle-based interference mitigation methods, so that the aims of mitigating the influence of unmanned aerial vehicle auxiliary interference and improving the system performance are fulfilled, and the influence of unmanned aerial vehicle auxiliary interference can be effectively mitigated; effective suppression of unmanned aerial vehicle auxiliary interference in an optical communication system is realized.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technology, and in particular to a method and device for free-space optical communication unmanned aerial vehicle assisted interference suppression. Background Art

[0002] Free space optical (FSO) communication technology is a wireless communication technology that uses lasers to transmit information in free space. FSO communication technology has the advantages of high transmission rate, good confidentiality, and strong anti-interference ability, so it has been widely used in military, aerospace, communication and other fields. However, FSO communication technology also has some disadvantages, such as being easily affected by weather conditions such as atmospheric turbulence and fog, and limited transmission distance. In order to overcome these shortcomings, a FSO communication technology based on intelligent reflecting surface (IRS) has been proposed.

[0003] IRS is a planar structure composed of multiple reflection units, each of which can independently adjust the phase and amplitude to achieve signal reflection and focusing. By introducing IRS in the FSO communication system, the transmission distance and reliability of the signal can be effectively improved. However, the IRS-assisted FSO communication system is also vulnerable to malicious interference, such as drone-assisted interference. Drone-assisted interference is a malicious attack method that uses drones to carry interference sources to interfere with the FSO communication system. Drone-assisted interference has the advantages of high flexibility and strong concealment, so it poses a serious threat to the security of the FSO communication system.

[0004] In order to mitigate the impact of UAV-assisted interference and improve the performance of IRS-assisted FSO communication systems, some methods have been proposed, such as signal processing-based methods, physical layer security-based methods, etc. However, these methods have some limitations, such as high computational complexity and limited performance improvement. Therefore, a new method is needed to mitigate the impact of UAV-assisted interference and improve the performance of IRS-assisted FSO communication systems. Summary of the invention

[0005] The present invention provides a method and device for suppressing UAV-assisted interference in free-space optical communication, which are used to realize UAV-assisted interference suppression in free-space optical communication.

[0006] In a first aspect, the present invention provides a free space optical communication system, the system comprising a transmitter, an IRS, a receiver and a UAV auxiliary interference source, characterized in that it comprises:

[0007] Obtaining an average bit error rate of the free space optical communication system;

[0008] Acquire a distance parameter, where the distance parameter is used to indicate a positional relationship between the IRS and a transmitter;

[0009] According to the average bit error rate, the distance parameter is adjusted to alleviate the impact of UAV-assisted interference and achieve UAV-assisted interference suppression.

[0010] According to the free space optical communication UAV assisted interference suppression method, it also includes:

[0011] Based on the system, a free space optical communication model is constructed, and probability density functions of legitimate channels and interference channels are constructed;

[0012] According to the free space optical communication model and the probability density function, it also includes: constructing probability density functions of legitimate channels and interference channels based on the free space optical communication system;

[0013] According to the probability density function, system performance indicators of the system using two detection methods, intensity modulation direct detection (IM-DD) and heterodyne detection (HD), are obtained, wherein the system performance indicators include an average bit error rate and an interruption probability;

[0014] A target detection method is determined based on the system performance indicator, and a configuration adjustment method of the system is determined based on the target detection method to alleviate the impact of drone auxiliary interference.

[0015] According to the free space optical communication UAV assisted interference suppression method, the distance parameter is the ratio of the distance between the transmitter and the IRS to the distance between the IRS and the receiver.

[0016] According to the free space optical communication UAV assisted interference suppression method, the step of adjusting the distance parameter according to the average bit error rate includes:

[0017] When the average bit error rate exceeds a preset optimal range, the distance between the transmitter and the IRS and / or the distance between the IRS and the receiver is adjusted.

[0018] According to the free-space optical communication UAV-assisted interference suppression method, the probability density function of constructing the legitimate channel and the interference channel based on the free-space optical communication model is specifically:

[0019] The probability density function of the legal channel is:

[0020]

[0021] When interfering with the receiving end, the probability density function of the interference channel is:

[0022]

[0023] When interfering with RIS, the probability density function of the interference channel is:

[0024]

[0025] Among them, α x and β x (x∈{p,q,J}), representing the influence of large-scale vortices and small-scale vortices, respectively. is the fraction of power collected at the center of the beam footprint. ξ x (x∈{p,q,J}) represents the pointing error faced by the legitimate signal or the interfering signal. p and h q They represent the channel gains of the S-IRS (source-intelligent reflection surface) and IRS-D (intelligent reflection surface-destination) links respectively.

[0026] According to the free space optical communication drone-assisted interference suppression method, the obtaining of the average bit error rate and interruption probability using the intensity modulation direct detection (IM-DD) detection method specifically includes:

[0027] When interfering with the receiving end, the average bit error rate when using IM / DD is:

[0028]

[0029] When interfering with RIS, the average bit error rate when using IM / DD is:

[0030]

[0031] When interfering with the receiving end, the outage probability when using IM / DD is:

[0032]

[0033] When interfering with RIS, the outage probability when using IM / DD is:

[0034]

[0035] According to the free space optical communication drone-assisted interference suppression method, the obtaining of the average bit error rate and interruption probability using a heterodyne detection (HD) detection method specifically includes:

[0036] When interfering with the receiving end, the average bit error rate when using HD is:

[0037]

[0038] When interfering with RIS, the average bit error rate when using HD is:

[0039]

[0040] When interfering with the receiving end, the outage probability when using HD is:

[0041]

[0042] When interfering with RIS, the outage probability when using HD is:

[0043]

[0044] Among them, α x and β x (x∈{p,q,J}), representing the influence of large-scale vortices and small-scale vortices, respectively. is the fraction of power collected at the center of the beam footprint. ξ x (x∈{p,q,J}) represents the pointing error faced by the legitimate signal or the interfering signal. p and h q They represent the channel gains of the S-IRS (source-intelligent reflection surface) and IRS-D (intelligent reflection surface-destination) links respectively. represents the smart reflective surface element at position P, where represents the amplitude reflection coefficient, and ψ represents the induced phase. is the angle of arrival; σ Aoa is the standard deviation of the drone’s orientation.

[0045] According to the free space optical communication UAV assisted interference suppression method, the step of determining the target detection method based on the system performance index includes:

[0046] Obtaining an average bit error rate and an outage probability of the system using an intensity modulation direct detection (IM-DD) detection method;

[0047] Obtaining an average bit error rate and an outage probability of the system using a heterodyne detection (HD) detection method;

[0048] When the average bit error rate and interruption probability of the system using the heterodyne detection (HD) detection method are lower than the average bit error rate and interruption probability of the system using the intensity modulation direct detection (IM-DD) detection method, the heterodyne detection (HD) detection method is determined as the target detection method.

[0049] In a second aspect, the present invention further provides a free-space optical communication UAV auxiliary interference suppression device, the device comprising:

[0050] A first processing module, configured to obtain an average bit error rate of the free space optical communication system;

[0051] a second processing module, configured to obtain a distance parameter, wherein the distance parameter is used to indicate a positional relationship between the IRS and the transmitter;

[0052] The third processing module is used to adjust the distance parameter according to the average bit error rate to alleviate the impact of drone-assisted interference and achieve drone-assisted interference suppression.

[0053] In a third aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the free-space optical communication drone-assisted interference suppression methods described above.

[0054] Compared with the prior art, the free-space optical communication UAV-assisted interference suppression method and device provided by the present invention has the following technical advantages:

[0055] The present invention provides a method and device for suppressing unmanned aerial vehicle-assisted interference in free-space optical communication, and relates to the field of wireless communication technology. The method comprises constructing a free-space optical communication system model; based on the model, obtaining an average bit error rate of the system; obtaining a distance parameter, the distance parameter being used to indicate the positional relationship between an IRS and a transmitter; and then adjusting the distance parameter according to the average bit error rate to mitigate the influence of unmanned aerial vehicle-assisted interference and achieve unmanned aerial vehicle-assisted interference suppression. The present invention achieves the goal of alleviating the influence of unmanned aerial vehicle-assisted interference and improving system performance by establishing a system model and cooperating with technical means such as deriving a probability density function, analyzing system performance, and an interference mitigation method based on unmanned aerial vehicles, thereby effectively alleviating the influence of unmanned aerial vehicle-assisted interference and achieving effective suppression of unmanned aerial vehicle-assisted interference in an optical communication system. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0057] Figure 1 It is a flow chart of the free space optical communication UAV assisted interference suppression method provided by the present invention;

[0058] Figure 2 It is a schematic diagram of a free space optical communication UAV assisted interference suppression model provided by the present invention;

[0059] Figure 3 It is a schematic diagram of a free space optical communication UAV-assisted jamming UAV-assisted jamming scenario provided by the present invention;

[0060] Figure 4 is a curve diagram of the relationship between the interruption probability and the signal-to-interference ratio under different interference probabilities provided by the present invention;

[0061] Figure 5 A schematic diagram of the relationship between the bit error rate and the signal-to-interference ratio for different arrival fluctuation angles provided for this example;

[0062] Figure 6 A schematic diagram of the relationship between the bit error rate and the signal-to-interference ratio under different interference probabilities provided for this example;

[0063] Figure 7 A schematic diagram of the relationship between bit error rate and signal-to-interference ratio under different turbulence intensities provided for this example;

[0064] Figure 8 A schematic diagram of the relationship between the bit error rate and the signal-to-interference ratio under different IRS positions provided for this example;

[0065] Fig. 9 A schematic diagram of the relationship between the bit error rate and the signal-to-interference ratio under different interference angles provided for this example. DETAILED DESCRIPTION

[0066] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0067] It should be noted that, in the description of the embodiments of the present invention, 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 includes 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 "include one..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0068] Combine the following Figure 1-Figure 9 The free-space optical communication UAV-assisted interference suppression method and device provided by the embodiments of the present invention are described.

[0069] Figure 1 : is a flow chart of the free space optical communication UAV assisted interference suppression method provided by the present invention, such as Figure 1 As shown, including but not limited to the following steps:

[0070] S101, obtaining an average bit error rate of the free space optical communication system.

[0071] Figure 2 Schematic diagram of the free space optical communication UAV auxiliary interference suppression system provided by the present invention. Figure 2 As shown, the free space optical communication system model includes a transmitter, an IRS, a receiver and a UAV auxiliary interference source. Figure 3 It is a schematic diagram of the free space optical communication UAV-assisted jamming UAV-assisted jamming scenario provided by the present invention.

[0072] The average bit error rate (ABER) of a free-space optical communication system is used to measure the reliability of the communication system and the accuracy of data transmission. Atmospheric turbulence, atmospheric attenuation, pointing errors and weather conditions are the main factors affecting the ABER in FSO systems. These factors can cause random fluctuations, energy attenuation and path deviation of the transmission beam, which in turn affects the quality of the received signal.

[0073] In order to calculate ABER, models such as Rayleigh fading model and log-normal fading model can be used to predict ABER. For example, on-off keying (OOK) modulation is often used in FSO systems. Through direct detection (IM / DD), the closed-form expression of the system's bit error rate can be derived, thereby analyzing the impact of parameters such as atmospheric turbulence on system performance.

[0074] S102, obtaining distance parameters.

[0075] The distance parameter is used to indicate the position relationship between the intelligent reflecting surface (IRS) and the transmitter in the system.

[0076] Optionally, the distance parameter is a ratio of a distance between the transmitter and the IRS to a distance between the IRS and the receiver.

[0077] The distance parameter is expressed as:

[0078] k p =L P / L q ;

[0079] Among them, L P is the distance between the transmitter and the IRS, L q is the distance between IRS and receiver.

[0080] S103: adjusting the distance parameter according to the average bit error rate to alleviate the influence of UAV-assisted interference and achieve UAV-assisted interference suppression.

[0081] It should be noted that the smaller the distance parameter value, the better the system ABER performance. A smaller distance parameter value means that the IRS is closer to the transmitter. By adjusting the distance parameter value, the effect of different IRS positions on the system ABER performance can be observed. For example, when k P =0.235, the corresponding At this time, the system's ABER performance is relatively good. This provides a specific quantitative indicator for UAV-assisted interference suppression. Among them, the parameters Represents the pointing error. The larger its value is, the better the system performance is.

[0082] Specifically, distance parameters in reducing interference effects include:

[0083] 1. Reduce path loss

[0084] When the IRS is close to the transmitter, the path loss of the signal on the transmission path from the transmitter to the IRS will decrease. In the case of drone-assisted interference, the interference to the legitimate signal during transmission is relatively weakened. Because the reduction in path loss makes the legitimate signal have stronger power when it reaches the IRS, it can counter the interference signal from the drone-assisted interference source to a certain extent.

[0085] In actual communication systems, as the IRS approaches the transmitter, the distance parameter value decreases, the signal attenuation in the initial transmission stage decreases, and the signal strength reaching the IRS increases. This makes the legitimate signal that reaches the receiver after being reflected by the IRS more advantageous, reducing the impact of drone interference on the system.

[0086] 2. The interference signal is relatively weakened

[0087] When the IRS is close to the transmitter, the path of the interference signal from the UAV auxiliary interference source to reach the IRS may become longer, or due to factors such as the angle, the intensity of the interference signal is relatively weakened when it reaches the IRS.

[0088] At the same time, since the IRS is closer to the transmitter, it can more effectively reflect the legitimate signal to the receiver, further improving the strength of the legitimate signal, thereby relatively reducing the impact of the interference signal.

[0089] For example, assuming that the UAV interference source is at a specific location, when the IRS is close to the transmitter, the path of the interference signal to the IRS and receiver may become more complicated, and the signal strength may be reduced. However, the legitimate signal can be better reflected and focused due to the optimized position of the IRS, which improves the performance of the system in the interference environment.

[0090] Distance parameters are used to optimize system performance, improve system transmission power, and achieve UAV-assisted interference suppression, including:

[0091] 1. Improve signal transmission quality

[0092] Lower distance parameter values ​​result in better ABER performance for the system, which means that the system can transmit information more accurately in the presence of UAV-assisted interference. By optimizing the position of the IRS and reducing the distance parameter value, the quality of the signal can be improved and the bit error rate can be reduced. This is essential to ensure the reliability and stability of the communication system.

[0093] For example, in practical applications, the lower ABER performance of the access system can ensure the accuracy of data transmission, reduce the number of retransmissions, and improve communication efficiency. In the scenario of drone-assisted interference, by adjusting the position of the IRS to optimize the distance parameter value, the system's anti-interference ability can be effectively improved to ensure signal quality.

[0094] 2. Provide support for interference mitigation methods

[0095] Determining the relationship between the distance parameter value and the system ABER performance provides an important basis for the proposed UAV-based interference mitigation method.

[0096] By adjusting the position of the IRS to optimize the distance parameter value, it can be combined with other interference mitigation measures (such as adjusting the position and transmission power of the drone, using heterodyne detection (HD) technology, etc.) to jointly improve the system's anti-interference capability.

[0097] For example, in actual interference mitigation strategies, the optimal position of the IRS can be determined based on the size of the distance parameter value. At the same time, the position and transmission power of the drone can be adjusted, and HD technology can be used to jointly deal with drone-assisted interference from multiple aspects to improve system performance.

[0098] In summary, the relationship that the smaller the distance parameter value (the closer the IRS is to the transmitter), the better the system ABER performance plays a key role in solving the technical problem of the present invention. It provides an effective technical approach to mitigate the impact of UAV-assisted interference by reducing path loss, weakening interference signals, and improving signal quality, and cooperates with other interference mitigation methods to jointly improve the performance of the smart reflector-assisted free-space optical communication system.

[0099] Optional, k p and The corresponding values ​​are shown in Table 1.

[0100] Table 1:

[0101]

[0103] Figure 4Figure 1 is a graph showing the relationship between outage probability and signal-to-interference ratio under different interference probabilities, showing the impact of different positions of the intelligent reflecting surface (IRS) on the average bit error rate (ABER) of the two scenarios. p The value increases, and the system ABER performance deteriorates. This shows that the closer the IRS is to the transmitter, the better the system ABER performance.

[0104] Among them, the parameters Represents the pointing error. The larger its value, the better the system performance. Figure 4 It can be seen that with The value increases, and the system ABER performance improves. Therefore, by adjusting the position of the IRS, the pointing error can be reduced, thereby optimizing and improving the system performance.

[0105] Based on the content of the above embodiment, as an optional embodiment, the free space optical communication UAV assisted interference suppression method provided by the present invention further includes:

[0106] Based on the free space optical communication system, constructing probability density functions of legitimate channels and interference channels;

[0107] According to the probability density function, system performance indicators of the system using two detection methods, intensity modulation direct detection (IM-DD) and heterodyne detection (HD), are obtained, wherein the system performance indicators include an average bit error rate and an interruption probability;

[0108] A target detection method is determined based on the system performance indicator, and a configuration adjustment method of the system is determined based on the target detection method to alleviate the impact of drone auxiliary interference.

[0109] Specifically, through the free-space optical communication model, the signal transmission path and the location of the interference source can be clearly identified, so that the probability density function of the channel can be derived based on factors such as path loss, pointing error and atmospheric turbulence.

[0110] For example, by analyzing the signal transmission relationship between the transmitter, smart reflector, receiver and interference source in the model, the characteristics of the channel can be determined and the probability density function can be derived.

[0111] Using the probability density functions of the legitimate channel and the interference channel, important performance indicators such as the average bit error rate and interruption probability under different detection methods can be calculated. These indicators directly reflect the communication quality and reliability of the system under drone-assisted interference.

[0112] For example, by substituting the probability density function into the calculation formula of the average bit error rate and the outage probability, the performance degradation of the system under different interference intensities can be quantitatively evaluated, thereby determining the specific impact of interference on system performance.

[0113] Optionally, the step of determining the target detection method based on the system performance indicator includes:

[0114] Obtaining an average bit error rate and an outage probability of the system using an intensity modulation direct detection (IM-DD) detection method;

[0115] Obtaining an average bit error rate and an outage probability of the system using a heterodyne detection (HD) detection method;

[0116] When the average bit error rate and interruption probability of the system using the heterodyne detection (HD) detection method are lower than the average bit error rate and interruption probability of the system using the intensity modulation direct detection (IM-DD) detection method, the heterodyne detection (HD) detection method is determined as the target detection method.

[0117] The analysis of the performance of different detection systems helps to select the appropriate modulation and demodulation method. After the performance analysis based on the derived probability density function, the performance of different detection methods such as IM / DD and HD under UAV-assisted interference can be compared. Based on the analysis results, the modulation and demodulation method that can better resist interference and improve system performance can be selected.

[0118] For example, if the average bit error rate and interruption probability of HD detection are significantly lower than those of IM / DD under certain interference conditions, HD detection can be selected to improve the system's anti-interference ability. Since the IM-DD detection method is low-cost and easy to implement, the IM-DD detection method is the best in the absence of interference.

[0119] Furthermore, the probability density function provides guidance for interference mitigation methods.

[0120] 1. Interference mitigation based on location optimization

[0121] Understanding the probability density functions of the legitimate and interfering channels helps determine the optimal location of the intelligent reflecting surface (IRS). By analyzing the relationship between the probability density function and the IRS location, it is possible to determine how the system performance improves when the IRS is closer to the transmitter under different interference conditions.

[0122] For example, according to the variation law of the probability density function, the IRS position that makes the system average bit error rate (ABER) performance the best can be determined, so as to optimize the system performance and reduce the impact of interference by adjusting the relative position between the IRS and the transmission source.

[0123] 2. Interference mitigation using heterodyne detection (HD) technology

[0124] The analysis results of the probability density function provide support for the use of HD technology. By comparing the performance indicators calculated based on the probability density function of IM / DD and HD in different scenarios, the advantages of the HD detection method in suppressing malicious interference can be clearly seen. This allows the targeted selection of the HD detection method to effectively suppress the impact of malicious interference on the system communication performance and improve the system's anti-interference ability.

[0125] In summary, deriving the probability density functions of legitimate channels and interference channels plays a vital role in solving the technical problem of mitigating the impact of UAV-assisted interference, and provides key theoretical support and technical basis for accurately evaluating interference impacts, system performance analysis, and the selection of interference mitigation methods.

[0126] Optionally, the probability density function of the legal channel is:

[0127]

[0128] where Γ(·) is the gamma function, It is the Meijer G function. This function comprehensively considers the impact of different parameters on the legal channel gain and describes the statistical characteristics of the legal channel through the combination of multiple parameters and the form of special functions.

[0129] When interfering with the receiving end, the probability density function of the interference channel is:

[0130]

[0131] in, The part represents the exponential term related to the arrival angle and standard deviation, δ(h J1 ) is the Dirac delta function, The Meijer G function also works together with these parameters and functions to reflect the statistical characteristics of the interference channel at the interference receiving end in a specific way.

[0132] When interfering with RIS, the probability density function of the interference channel is:

[0133]

[0134] When interference acts on a smart reflector surface (RIS), this function describes the probability density of the interference channel at this time. Similar to the previous function, it contains terms related to the arrival angle and standard deviation, Dirac delta function, and Meijer G function. Through the combination of these parameters and functions, the statistical characteristics of the interference channel when the interference acts on the RIS are reflected.

[0135] Among them, α x and β x(x∈{p,q,J}), representing the influence of large-scale vortices and small-scale vortices, respectively. is the fraction of power collected at the center of the beam footprint. ξ x (x∈{p,q,J}) represents the pointing error faced by the legitimate signal or the interfering signal. p and h q They represent the channel gains of the S-IRS (source-intelligent reflection surface) and IRS-D (intelligent reflection surface-destination) links respectively.

[0136] Furthermore, according to the free space optical communication model and the probability density function, system performance indicators of the system using two detection methods, namely intensity modulation direct detection (IM-DD) and heterodyne detection (HD), are obtained.

[0137] Among them, the system performance indicators include average bit error rate and outage probability;

[0138] Optionally, the bit error rate and the outage probability are obtained by integrating a probability density function.

[0139] 1. Used to accurately assess the impact of interference on system performance

[0140] 1. Average bit error rate and outage probability are used to quantify the interference effect

[0141] The average bit error rate and interruption probability are important indicators for measuring the performance of communication systems. By deriving these two indicators, we can specifically quantify the impact of drone-assisted interference on communication systems.

[0142] For example, a higher average bit error rate means a higher number of bits received incorrectly during transmission, while the interruption probability reflects the possibility of communication interruption. These quantitative results can intuitively show the extent of damage caused by interference to the system and provide a clear basis for taking further targeted mitigation measures.

[0143] 2. Obtain the system performance indicators of the two detection methods, intensity modulation direct detection (IM-DD) and heterodyne detection (HD), for comparing the anti-interference capabilities of different detection systems.

[0144] The performance analysis of the two detection systems, IM / DD and HD, including the calculation of their respective average bit error rates and outage probabilities, can be used to compare the anti-interference capabilities of different detection methods in the face of UAV-assisted interference.

[0145] For example, if under the same interference conditions, the average bit error rate and interruption probability of the HD system are significantly lower than those of the IM / DD system, then it can be concluded that the HD system has an advantage in anti-interference, providing a reference for selecting a more effective detection method.

[0146] Then, the appropriate detection method can be selected based on the performance analysis of the system performance indicators.

[0147] By analyzing the average bit error rate and outage probability, it is possible to determine which detection method provides better communication performance in a specific interference environment. If a system using HD detection shows a lower average bit error rate and outage probability when facing drone-assisted interference, then HD technology can be selected as the system's target detection method when performing drone-assisted interference suppression.

[0148] For example, in an actual communication system, the system configuration can be adjusted according to the results of the performance analysis of the system performance indicators, and the HD detection technology can be used to improve the anti-interference ability of the system.

[0149] For example, after determining the optimal position of the intelligent reflecting surface (IRS), it can be further combined with HD detection technology to adjust system parameters according to the performance indicators under different detection methods to achieve better interference mitigation effects.

[0150] At the same time, through continuous monitoring and analysis of the average bit error rate and interruption probability, the interference mitigation strategy can be adjusted in time to ensure that the system can maintain good communication performance under different interference conditions.

[0151] Specifically, a target detection method is determined based on the system performance indicator, and a system configuration adjustment method is determined based on the target detection method to alleviate the impact of drone auxiliary interference.

[0152] For example, based on the problems found in the performance analysis, system parameters such as transmitter power and receiver sensitivity can be adjusted to reduce the impact of interference on system performance.

[0153] Optionally, the obtaining of an average bit error rate and an interruption probability using an intensity modulation direct detection (IM-DD) detection method specifically includes:

[0154] When interfering with the receiving end, the average bit error rate when using IM / DD is:

[0155]

[0156] This function represents the average bit error rate at the interference receiving end when using intensity modulation direct detection (IM / DD). Among them, parameters such as ρ and θ have specific physical meanings in the specific system, and the combination of the gamma function and the Meijer G function reflects the statistical characteristics of the system in this case.

[0157] When interfering with RIS, the average bit error rate when using IM / DD is:

[0158]

[0159] This function gives the average bit error rate when interference acts on RIS and uses IM / DD. Again, the combination of various parameters and functions describes the performance characteristics of the system in this specific case.

[0160] When interfering with the receiving end, the outage probability when using IM / DD is:

[0161]

[0162] This function represents the outage probability when the interference receiving end is in the IM / DD mode, and describes the possibility of system outage in this case through the integral form and the combination of multiple parameters and special functions.

[0163] When interfering with RIS, the outage probability when using IM / DD is

[0164]

[0165] This function gives the probability of interruption when interference acts on RIS and IM / DD detection is used. Similar to the previous function, the probability of system interruption in this case is reflected through a specific combination of parameters and functions.

[0166] Among them, α x and β x (x∈{p,q,J}), representing the influence of large-scale vortices and small-scale vortices, respectively. is the fraction of power collected at the center of the beam footprint. ξ x (x∈{p,q,J}) represents the pointing error faced by the legitimate signal or the interfering signal. p and h q They represent the channel gains of the S-IRS (source-intelligent reflection surface) and IRS-D (intelligent reflection surface-destination) links respectively. represents the smart reflective surface element at position P, where represents the amplitude reflection coefficient, and ψ represents the induced phase. is the angle of arrival; σ Aoa is the standard deviation of the drone’s orientation.

[0167] Optionally, obtaining an average bit error rate and an outage probability using a heterodyne detection (HD) detection method specifically includes:

[0168] When interfering with the receiving end, the average bit error rate when using HD is:

[0169]

[0170] When interfering with RIS, the average bit error rate when using HD is:

[0171]

[0172] When interfering with the receiving end, the outage probability when using HD is:

[0173]

[0174] When interfering with RIS, the outage probability when using HD is:

[0175]

[0176] Figure 5 A schematic diagram of the relationship between the bit error rate and the signal-to-interference ratio for different arrival fluctuation angles provided for this example; Figure 6 A schematic diagram of the relationship between the bit error rate and the signal-to-interference ratio under different interference probabilities provided for this example; Figure 7 A schematic diagram of the relationship between bit error rate and signal-to-interference ratio under different turbulence intensities provided for this example; Figure 8 A schematic diagram of the relationship between the bit error rate and the signal-to-interference ratio under different IRS positions provided for this example; Fig. 9 A schematic diagram of the relationship between the bit error rate and the signal-to-interference ratio under different interference angles provided for this example.

[0177] The present invention uses ABER and outage probability as main performance evaluation indicators, and the effectiveness of the proposed method can be proved through theoretical analysis and simulation verification.

[0178] It should be noted that those skilled in the art can Figure 5 , 4 , 6, 7 and 8, it can be concluded that, under the same conditions, the use of HD detection can effectively suppress the impact of malicious interference on the communication performance of the free space optical communication system assisted by the optical smart reflection surface.

[0179] The present invention also provides a free space optical communication UAV auxiliary interference suppression device, which is characterized by comprising:

[0180] A first processing module, configured to obtain an average bit error rate of the free space optical communication system;

[0181] a second processing module, configured to obtain a distance parameter, wherein the distance parameter is used to indicate a positional relationship between the IRS and the transmitter;

[0182] The third processing module is used to adjust the distance parameter according to the average bit error rate to alleviate the impact of drone-assisted interference and achieve drone-assisted interference suppression.

[0183] It should be noted that the application function association prediction device provided in the embodiment of the present invention can execute the free space optical communication drone assisted interference suppression method described in any of the above embodiments during specific operation, which will not be elaborated in this embodiment.

[0184] On the other hand, the present invention also provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions. When the program instructions are executed by a computer, the computer can execute the free-space optical communication UAV-assisted interference suppression method provided in the above-mentioned embodiments, and the method includes: obtaining an average bit error rate of the free-space optical communication system; a distance parameter, wherein the distance parameter is used to indicate a positional relationship between the IRS and the transmitter; and adjusting the distance parameter according to the average bit error rate to alleviate the impact of UAV-assisted interference and achieve UAV-assisted interference suppression.

[0185] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, it is implemented to execute the free-space optical communication drone-assisted interference suppression method provided in the above-mentioned embodiments. The method includes: obtaining an average bit error rate of the free-space optical communication system; a distance parameter, wherein the distance parameter is used to indicate a positional relationship between the IRS and the transmitter; and adjusting the distance parameter according to the average bit error rate to alleviate the impact of drone-assisted interference and achieve drone-assisted interference suppression.

[0186] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0187] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0188] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A free space optical communication UAV-assisted interference suppression method is applied to a free space optical communication system, wherein the system includes a transmitter, an IRS, a receiver, and a UAV-assisted interference source, characterized in that: include: Obtaining an average bit error rate of the free space optical communication system; Acquire a distance parameter, where the distance parameter is used to indicate a positional relationship between the IRS and a transmitter; According to the average bit error rate, the distance parameter is adjusted to alleviate the impact of UAV-assisted interference and achieve UAV-assisted interference suppression.

2. The free space optical communication UAV-assisted interference suppression method according to claim 1, characterized in that: Also includes: Based on the free space optical communication system, constructing probability density functions of legitimate channels and interference channels; According to the probability density function, system performance indicators of the system using two detection methods, intensity modulation direct detection (IM-DD) and heterodyne detection (HD), are obtained, wherein the system performance indicators include an average bit error rate and an interruption probability; A target detection method is determined based on the system performance indicator, and a configuration adjustment method of the system is determined based on the target detection method to alleviate the impact of drone auxiliary interference.

3. The free space optical communication UAV-assisted interference suppression method according to claim 1, characterized in that: The distance parameter is the ratio of the distance between the transmitter and the IRS to the distance between the IRS and the receiver.

4. The free space optical communication UAV assisted interference suppression method according to claim 1, characterized in that: According to the average bit error rate, the step of adjusting the distance parameter comprises: When the average bit error rate exceeds a preset optimal range, the distance between the transmitter and the IRS and / or the distance between the IRS and the receiver is adjusted.

5. The free space optical communication UAV-assisted interference suppression method according to claim 1, characterized in that: The probability density function of constructing the legitimate channel and the interference channel based on the free space optical communication model is specifically: The probability density function of the legal channel is: When interfering with the receiving end, the probability density function of the interference channel is: When interfering with RIS, the probability density function of the interference channel is: Among them, α x and β x (x∈{p,q,J}), which represent the influence of large-scale vortices and small-scale vortices, respectively; is the fraction of power collected at the center of the beam footprint; ξ x (x∈{p,q,J}) represents the pointing error faced by the legitimate signal or the interference signal; h p and h q They represent the channel gains of the S-IRS (source-intelligent reflection surface) and IRS-D (intelligent reflection surface-destination) links respectively.

6. The free space optical communication UAV-assisted interference suppression method according to claim 5, characterized in that: The obtaining of the average bit error rate and the interruption probability using the intensity modulation direct detection (IM-DD) detection method specifically includes: When interfering with the receiving end, the average bit error rate when using IM / DD is: When interfering with RIS, the average bit error rate when using IM / DD is: When interfering with the receiving end, the outage probability when using IM / DD is: When interfering with RIS, the outage probability when using IM / DD is Among them, α x and β x (x∈{p,q,J}), which represent the influence of large-scale vortices and small-scale vortices, respectively; is the fraction of power collected at the center of the beam footprint; ξ x (x∈{p,q,J}) represents the pointing error faced by the legitimate signal or the interference signal; h p and h q They represent the channel gains of the S-IRS (source-intelligent reflector) and IRS-D (intelligent reflector-destination) links respectively; represents the smart reflective surface element at position P, where represents the amplitude reflection coefficient, ψ represents the induced phase; is the angle of arrival; σ Aoa is the standard deviation of the drone’s orientation.

7. The free space optical communication UAV-assisted interference suppression method according to claim 5, characterized in that: The obtaining of the average bit error rate and the interruption probability using a heterodyne detection (HD) detection method specifically includes: When interfering with the receiving end, the average bit error rate when using HD is: When interfering with RIS, the average bit error rate when using HD is: When interfering with the receiving end, the outage probability when using HD is: When interfering with RIS, the outage probability when using HD is: Among them, α x and β x (x∈{p,q,J}), which represent the influence of large-scale vortices and small-scale vortices, respectively; is the fraction of power collected at the center of the beam footprint; ξ x (x∈{p,q,J}) represents the pointing error faced by the legitimate signal or the interference signal; h p and h q They represent the channel gains of the S-IRS (source-intelligent reflector) and IRS-D (intelligent reflector-destination) links respectively; represents the smart reflective surface element at position P, where represents the amplitude reflection coefficient, ψ represents the induced phase; is the angle of arrival; σ Aoa is the standard deviation of the drone’s orientation.

8. The free space optical communication UAV-assisted interference suppression method according to claim 2, characterized in that: The step of determining the target detection method based on the system performance indicator includes: Obtaining an average bit error rate and an outage probability of the system using an intensity modulation direct detection (IM-DD) detection method; Obtaining an average bit error rate and an outage probability of the system using a heterodyne detection (HD) detection method; When the average bit error rate and interruption probability of the system using the heterodyne detection (HD) detection method are lower than the average bit error rate and interruption probability of the system using the intensity modulation direct detection (IM-DD) detection method, the heterodyne detection (HD) detection method is determined as the target detection method.

9. A free space optical communication UAV auxiliary interference suppression device, characterized in that: include: A first processing module, configured to obtain an average bit error rate of the free space optical communication system; a second processing module, configured to obtain a distance parameter, wherein the distance parameter is used to indicate a positional relationship between the IRS and the transmitter; The third processing module is used to adjust the distance parameter according to the average bit error rate to alleviate the impact of drone-assisted interference and achieve drone-assisted interference suppression.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the free-space optical communication drone-assisted interference suppression method as described in any one of claims 1 to 8 are implemented.

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