Heterogeneous data fusion transmission method and system for airborne multimode satellite communication

Abstract

The invention relates to the technical field of data fusion transmission, and provides a heterogeneous data fusion transmission method and system for airborne multimode satellite communication. Acquiring real-time communication parameters including a dynamic spectrum occupancy state, a polarization direction difference and a hidden transmission demand level; generating a dynamic frequency hopping control instruction based on the time-varying characteristic of the dynamic spectrum occupancy state, driving carrier switching and reserving a spectrum isolation area between adjacent carriers; performing orthogonal polarization diversity analysis on the carrier switching result based on the polarization direction difference, suppressing cross polarization interference and outputting multiple paths of baseband signals; calling a preset waveform parameter library according to the hidden demand level to determine a modulation parameter, and loading the baseband signal to the asymmetric phase subcarrier to generate a hidden modulation waveform; and fusing the frequency hopping instruction and the hidden modulation waveform to generate a cooperative modulation instruction, and controlling the radio frequency unit to realize anti-interference fusion transmission. According to the technical scheme provided by the invention, the anti-interference capability of fusion transmission of multi-mode satellite data in a dynamic spectrum environment is improved.

Description

Technical Field

[0001] This application relates to the technical field of data fusion transmission, and particularly to a heterogeneous data fusion transmission method and system for airborne multi-mode satellite communication. Background Art

[0002] In the scenario of airborne multi-mode satellite communication, the aircraft needs to simultaneously access multiple heterogeneous satellite nodes (such as low-earth orbit, medium-earth orbit, and geostationary orbit satellites), facing multiple challenges including dynamic spectrum resource preemption, cross-band interference suppression, and covert transmission requirements. Due to the high-speed mobility of the airborne platform and the spectrum strategy differences of satellite nodes, it is necessary to achieve the coordination of multi-band dynamic preemption, co-frequency interference suppression, and low probability of intercept transmission to ensure the real-time and reliable transmission of high-priority data.

[0003] The current mainstream solution adopts dynamic spectrum access technology based on software-defined radio (SDR), combined with an adaptive modulation and coding (AMC) mechanism. This solution detects available frequency bands through a spectrum sensing module, selects hopping frequency points according to preset priorities, and uses AMC to adjust the modulation method and coding rate to adapt to the channel quality. For co-frequency interference, a frequency-domain filtering combined with a power control strategy is adopted to suppress the impact of strong interference signals on the communication link.

[0004] The existing solutions have the following defects: Dynamic frequency hopping depends on a fixed priority list and cannot adapt to the rapid changes in the spectrum occupancy state in real time, resulting in low spectrum resource utilization and significant switching delays; Frequency-domain filtering is difficult to eliminate the cross-interference between orthogonally polarized signals in the same frequency band, especially when the polarization directions of satellite nodes are quite different, the bit error rate increases sharply; The modulation parameters of AMC are fixed, and the time-frequency characteristics of the signals are regular, making it easy to be recognized by the enemy's detection equipment and targeted interference can be implemented. Summary of the Invention

[0005] This application provides a heterogeneous data fusion transmission method and system for airborne multi-mode satellite communication to solve the problem of insufficient anti-interference ability in the fusion transmission of multi-mode satellite data in a dynamic spectrum environment in the prior art.

[0006] In a first aspect, this application provides a heterogeneous data fusion transmission method for airborne multi-mode satellite communication, including: Obtaining real-time communication parameters between an airborne data processing system and multiple satellite nodes, where the real-time communication parameters include the dynamic spectrum occupancy state, polarization direction difference, and covert transmission requirement level of each satellite node; Generating a dynamic frequency hopping control instruction according to the time-varying characteristics of the dynamic spectrum occupancy state, and through the dynamic frequency hopping control instruction, enabling the airborne data processing system to perform carrier switching triggered by spectrum sensing between authorized frequency bands and unauthorized frequency bands, and retaining a spectrum isolation area between adjacent carriers; Based on the polarization direction difference, the airborne data processing system performs orthogonal polarization diversity analysis on the carrier switching result to eliminate the cross-polarization interference component within the same frequency band in the spectrum isolation area, and outputs multiple baseband signals according to the diversity analysis result; Based on the covert transmission requirement level, a preset waveform modulation parameter library is called to determine a parameter set for weighted fractional Fourier transform. According to the parameter set, the multiple baseband signals are loaded onto a subcarrier set with asymmetric phase characteristics to generate a covert modulation waveform; The dynamic frequency hopping control instruction and the spectrum spreading range of the covert modulation waveform are input into the fusion control module of the airborne data processing system, and then a collaborative modulation instruction is output. The airborne radio frequency unit is controlled by the collaborative modulation instruction to achieve multi-mode satellite data anti-interference fusion transmission in a dynamic spectrum sharing environment.

[0007] Optionally, the step of based on the covert transmission requirement level, calling a preset waveform modulation parameter library to determine a parameter set for weighted fractional Fourier transform, and loading the multiple baseband signals onto a subcarrier set with asymmetric phase characteristics according to the parameter set to generate a covert modulation waveform includes: According to the discretization level identifier corresponding to the covert transmission requirement level, a parameter combination for fractional order transform is matched from the preset waveform modulation parameter library. The parameter combination includes a phase rotation sequence and an order factor; The phase rotation sequence is decomposed into multiple phase rotation amounts with non-uniform distribution, and based on the order factor, a phase weight coefficient of each subcarrier in the subcarrier set, which has a non-linear mapping relationship with the phase rotation amount, is calculated; The multiple baseband signals are allocated to the subcarrier set according to a preset ratio. The allocated baseband signals are subjected to phase rotation superposition according to the phase weight coefficient of each subcarrier in the subcarrier set, and a subcarrier unit is generated according to the superposition result; The subcarrier units are interleaved and arranged in the time-frequency domain, and a phase synchronization operation is performed on the arranged subcarrier units according to the timing rule of the phase rotation sequence to generate a spectrum-spread covert modulation waveform.

[0008] Optionally, the step of generating a dynamic frequency hopping control instruction according to the time-varying characteristics of the dynamic spectrum occupancy state, and enabling the airborne data processing system to perform spectrum sensing-triggered carrier switching between the authorized frequency band and the unauthorized frequency band through the dynamic frequency hopping control instruction, and retaining the spectrum isolation area between adjacent carriers includes: Availability parameters of each frequency band are extracted from the dynamic spectrum occupancy state. The availability parameters include the length of the idle time slot of the frequency band, the interference intensity threshold, and the occupancy duration of the adjacent frequency band; Divide the frequency hopping time window according to the length of the idle time slot of the frequency band, and perform priority sorting on the candidate frequency band sets of the authorized frequency band and the unauthorized frequency band based on the interference intensity threshold to generate a dynamic frequency hopping sequence including frequency hopping timing and frequency band switching rules; Within the frequency hopping time window, trigger a spectrum sensing instruction according to the frequency band switching rule in the dynamic frequency hopping sequence, detect the instantaneous interference intensity of the candidate frequency band set through the spectrum sensing instruction, and generate a carrier switching action based on the detection result; Adjust the frequency band interval between the current carrier and the adjacent carrier according to the occupancy duration of the adjacent frequency band, so that the width of the frequency band interval meets the preset spectrum isolation area rule, and perform a carrier switching action based on the spectrum isolation area rule to complete the spectrum isolation area configuration.

[0009] Optionally, based on the polarization direction difference, perform orthogonal polarization diversity analysis on the carrier switching result through the airborne data processing system to eliminate the cross-polarization interference component within the same frequency band of the spectrum isolation area, and output multi-channel baseband signals according to the diversity analysis result, including: Extract the polarization reception parameters of each satellite node according to the polarization direction difference, where the polarization reception parameters include the polarization angle deviation amount, the orthogonal polarization signal strength ratio, and the cross-polarization interference amplitude; Based on the polarization angle deviation amount, perform orthogonal polarization decomposition on the carrier switching result through the airborne data processing system. The orthogonal polarization decomposition process decomposes each carrier signal into a horizontal polarization component and a vertical polarization component, and records the time-frequency domain distribution characteristics of each component; Adjust the synthesis weight of the horizontal polarization component and the vertical polarization component according to the orthogonal polarization signal strength ratio, and at the same time use the cross-polarization interference amplitude to perform inverse-phase superposition cancellation on the residual interference component within the same frequency band to generate an orthogonal polarization signal pair; Construct a polarization synthesis rule based on the orthogonal polarization signal pair and the time-frequency domain distribution characteristics, and synthesize the horizontal polarization component and the vertical polarization component into multi-channel baseband signals according to the adjusted synthesis weight according to the polarization synthesis rule.

[0010] Optionally, the step of dividing the frequency hopping time window according to the length of the idle time slot of the frequency band, and performing priority sorting on the candidate frequency band sets of the authorized frequency band and the unauthorized frequency band based on the interference intensity threshold to generate a dynamic frequency hopping sequence including frequency hopping timing and frequency band switching rules includes: Divide the continuous available frequency band into frequency hopping time windows according to the length of the idle time slot of the frequency band, and the window duration of the frequency hopping time window does not exceed the minimum value of the length of the idle time slot of the frequency band; Screen for low-interference candidate frequency bands in the authorized and unauthorized frequency bands based on the interference intensity threshold, and prioritize the low-interference candidate frequency bands from low to high according to the interference intensity threshold; Allocate the residence duration of the corresponding frequency band to the sorted low-interference candidate frequency bands to generate a frequency band residence duration list; Align the hopping time window with the frequency band residence duration list along the time axis, and generate a dynamic hopping sequence including hopping timing, frequency band identification, and residence duration in combination with the silent period of the hopping time window.

[0011] Optionally, the adjusting the synthesis weight of the horizontal polarization component and the vertical polarization component according to the orthogonal polarization signal intensity ratio, and simultaneously using the cross-polarization interference amplitude to perform inverse-phase superposition cancellation on the residual interference components within the same frequency band to generate an orthogonal polarization signal pair includes: Calculate the synthesis ratio coefficient of the horizontal polarization component and the vertical polarization component according to the orthogonal polarization signal intensity ratio, and generate a weighted polarization component based on the synthesis ratio coefficient; Generate an inverse-phase cancellation signal with a phase opposite to that of the residual interference component according to the cross-polarization interference amplitude, and superimpose the inverse-phase cancellation signal on the weighted polarization component; Perform time-frequency domain energy equalization processing on the superimposed signal. The energy equalization process eliminates the delay spread component of the residual interference component within the same frequency band to generate an intermediate polarization signal; Align the orthogonal components of the intermediate polarization signal according to the preset time-frequency synchronization rule to generate an orthogonal polarization signal pair.

[0012] Optionally, the inputting the dynamic hopping control instruction and the frequency spectrum spreading range of the covert modulation waveform into the fusion control module of the airborne data processing system and then outputting a collaborative modulation instruction, and controlling the airborne radio frequency unit to achieve multi-mode satellite data anti-interference fusion transmission in a dynamic spectrum sharing environment through the collaborative modulation instruction includes: Analyze the hopping timing parameters and frequency band residence duration in the dynamic hopping control instruction, and extract the frequency coverage interval corresponding to the frequency spectrum spreading range of the covert modulation waveform; Adjust the sub-carrier phase distribution parameters of the covert modulation waveform according to the overlapping relationship between the hopping timing parameters and the frequency coverage interval to generate hopping-synchronized collaborative modulation parameters; Match the frequency band residence duration with the time-frequency resource allocation ratio of the collaborative modulation parameters, and calculate the power allocation coefficient of the airborne radio frequency unit in each frequency band according to the matching degree; Dynamically weight the collaborative modulation parameters as a collaborative modulation instruction according to the power allocation coefficient, and control the airborne radio frequency unit to perform multi-mode satellite data anti-interference fusion transmission through the collaborative modulation instruction.

[0013] In a second aspect, the present application provides a heterogeneous data fusion transmission system for airborne multi-mode satellite communication, including: An acquisition module, configured to acquire real-time communication parameters between an airborne data processing system and multiple satellite nodes, where the real-time communication parameters include the dynamic spectrum occupancy status, polarization direction difference, and covert transmission requirement level of each satellite node; An execution module, configured to generate a dynamic frequency hopping control instruction according to the time-varying characteristics of the dynamic spectrum occupancy status, and cause the airborne data processing system to perform carrier switching triggered by spectrum sensing between an authorized frequency band and an unauthorized frequency band through the dynamic frequency hopping control instruction, and retain a spectrum isolation area between adjacent carriers; An output module, configured to perform orthogonal polarization diversity analysis on the carrier switching result through the airborne data processing system based on the polarization direction difference, so as to eliminate the cross-polarization interference component within the same frequency band of the spectrum isolation area, and output multiple baseband signals according to the diversity analysis result; A generation module, configured to determine a parameter set of weighted fractional Fourier transform based on the covert transmission requirement level by invoking a preset waveform modulation parameter library, and load the multiple baseband signals onto a subcarrier set with asymmetric phase characteristics according to the parameter set to generate a covert modulation waveform; A control module, configured to input the dynamic frequency hopping control instruction and the spectrum spreading range of the covert modulation waveform into a fusion control module of the airborne data processing system, and then output a cooperative modulation instruction, and control an airborne radio frequency unit to achieve anti-interference fusion transmission of multi-mode satellite data in a dynamic spectrum sharing environment through the cooperative modulation instruction.

[0014] In a third aspect, an embodiment of the present application provides a computing device, including a processing component and a storage component; the storage component stores one or more computer instructions; the one or more computer instructions are used to be called and executed by the processing component to implement a heterogeneous data fusion transmission method for airborne multi-mode satellite communication as described in the first aspect above.

[0015] In a fourth aspect, an embodiment of the present application provides a computer storage medium, storing a computer program, where when the computer program is executed by a computer, it implements a heterogeneous data fusion transmission method for airborne multi-mode satellite communication as described in the first aspect.

[0016] In an embodiment of the present application, real-time communication parameters between an airborne data processing system and multiple satellite nodes are obtained. The real-time communication parameters include the dynamic spectrum occupancy status, polarization direction difference, and covert transmission requirement level of each satellite node. A dynamic frequency hopping control instruction is generated according to the time-varying characteristics of the dynamic spectrum occupancy status. Through the dynamic frequency hopping control instruction, the airborne data processing system performs carrier switching triggered by spectrum sensing between authorized frequency bands and unauthorized frequency bands, and a spectrum isolation area between adjacent carriers is reserved. Based on the polarization direction difference, the airborne data processing system performs orthogonal polarization diversity analysis on the carrier switching result to eliminate the cross-polarization interference component within the same frequency band of the spectrum isolation area, and outputs multiple baseband signals according to the diversity analysis result. Based on the covert transmission requirement level, a parameter set of weighted fractional Fourier transform is determined by invoking a preset waveform modulation parameter library, and the multiple baseband signals are loaded onto a subcarrier set with asymmetric phase characteristics according to the parameter set to generate a covert modulation waveform. The dynamic frequency hopping control instruction and the spectrum spreading range of the covert modulation waveform are input into the fusion control module of the airborne data processing system, and then a cooperative modulation instruction is output. Through the cooperative modulation instruction, the airborne radio frequency unit is controlled to achieve anti-interference fusion transmission of multi-mode satellite data in a dynamic spectrum sharing environment.

[0017] The technical solution of the present application has the following beneficial effects: Real-time perception of the dynamic spectrum status, polarization difference, and covert requirements between the airborne side and multiple satellite nodes provides an environmental perception basis for dynamic spectrum preemption and anti-interference transmission. Dynamic preemption of authorized / unauthorized frequency bands is achieved through carrier switching triggered by spectrum sensing, and adjacent frequency band interference is reduced by combining the spectrum isolation area reservation mechanism. The received signal is diversity-received using the polarization direction difference to suppress cross-polarization interference in the same frequency band and improve the signal-to-noise ratio and purity of multiple baseband signals. The WFRFT parameter set is dynamically adapted based on the covert requirements, and the baseband signal is loaded onto subcarriers with asymmetric phases to achieve spectrum spreading modulation with a low probability of intercept. The frequency hopping instruction and the spectrum characteristics of the covert waveform are fused to generate an anti-interference cooperative instruction to ensure reliable fusion transmission of multi-mode data in a dynamic spectrum environment.

[0018] Further, according to the level of covert transmission requirements, match the fractional transformation parameter combinations in the preset parameter library, decompose the phase rotation sequence into non-uniformly distributed phase rotation amounts, calculate the subcarrier phase weight coefficients in combination with the order factor; allocate multiple baseband signals to the subcarriers proportionally, and generate subcarrier units by rotating and superimposing the signals based on the phase weights; through time-frequency domain interleaving arrangement and phase synchronization operations, form a covert modulation waveform with spectrum spreading. Through non-uniform phase rotation and non-linear weight mapping, the subcarrier signals exhibit a randomized phase distribution characteristic, destroying the time-frequency domain regularity of the signals and reducing the feature recognition probability of enemy detection equipment; combined with time-frequency interleaving and phase synchronization operations, further spread the signal energy distribution range to achieve highly covert transmission.

[0019] These aspects or other aspects of the present application will be more clearly understood in the following description of the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0021] Figure 1 The flowchart of a heterogeneous data fusion transmission method for airborne multi-mode satellite communication provided by the present application is shown; Figure 2 The structural schematic diagram of a heterogeneous data fusion transmission system for airborne multi-mode satellite communication provided by the present application is shown; Figure 3 The structural schematic diagram of a computing device provided by the present application is shown. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] In order to enable those skilled in the art to better understand the solutions of the present application, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application.

[0023] In some of the processes described in the specification, claims, and the above-mentioned drawings of this application, a plurality of operations appear in a specific order. However, it should be clearly understood that these operations may not be executed in the order in which they appear herein or may be executed in parallel. The serial numbers of the operations, such as 101, 102, etc., are only used to distinguish different operations, and the serial numbers themselves do not represent any execution order. In addition, these processes may include more or fewer operations, and these operations may be executed in sequence or in parallel. It should be noted that the descriptions such as "first", "second", etc. in this article are used to distinguish different messages, devices, modules, etc., do not represent a sequence, and do not limit that "first" and "second" are of different types.

[0024] Researchers have found that existing satellite communication systems face three major bottleneck problems in the scenario of airborne multi-mode heterogeneous networking, namely, low efficiency of dynamic spectrum resource allocation, insufficient ability to suppress co-frequency interference, and poor signal concealment. Based on this, a heterogeneous data fusion transmission method for airborne multi-mode satellite communication is provided. Specifically, by real-time sensing the spectrum state differences and polarization characteristics of multiple satellite nodes, a frequency band switching mechanism triggered by dynamic spectrum sensing is constructed, and co-frequency multiplexed signals are separated by combining polarization diversity reception and interference cancellation techniques; further, sub-carrier waveforms with asymmetric phase modulation are generated according to the dynamic concealment transmission requirements, and the dynamic adaptation of spectrum spreading and frequency hopping timing is achieved through cooperative control. This method can improve the spectrum preemption efficiency of multi-mode satellite data in a high-dynamic spectrum environment, suppress cross-band cross-interference, and at the same time reduce the interception probability by randomizing the time-frequency characteristics of the signal, ensuring the reliability of anti-interference and concealment fusion transmission.

[0025] The technical solution of this application is applicable to the scenarios of multi-band dynamic preemption and anti-interference transmission in airborne multi-mode satellite communication.

[0026] Next, the technical solutions in the embodiments of this application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of this application.

[0027] Figure 1 The following is a flowchart of a heterogeneous data fusion transmission method for airborne multi-mode satellite communication provided by an embodiment of this application, as Figure 1 shown, the method includes: 101. Obtain the real-time communication parameters between the airborne data processing system and multiple satellite nodes, where the real-time communication parameters include the dynamic spectrum occupancy status, polarization direction difference, and concealment transmission requirement level of each satellite node; In this step, the dynamic spectrum occupancy status refers to the real-time occupancy of authorized and unauthorized frequency bands by each satellite node during communication, including frequency band identification, occupancy start time, duration, and instantaneous interference intensity level. The polarization direction difference is the phase offset angle, amplitude ratio difference, and polarization angle deviation amount between the horizontal polarization component and the vertical polarization component of the transmitted signals of different satellite nodes during spatial propagation. The covert transmission requirement level is a covertness quantization index dynamically divided according to the communication task type and the complexity of the electromagnetic environment, including the spectrum spreading range, signal phase randomization intensity, and anti-interception priority coefficient.

[0028] In the embodiments of the present application, first, the airborne data processing system performs frequency-domain scanning on the frequency bands covered by the satellite nodes through a broadband radio frequency front end, uses the sliding window energy detection technology to capture the signal intensity changes of each frequency band in real time during the scanning process, and generates a dynamic spectrum occupancy status matrix by combining the occupancy start time and duration of the frequency bands; second, in the carrier synchronization stage, the satellite signals are received through a polarization-sensitive array antenna, the horizontal and vertical polarization components of the satellite signals are separated by using the orthogonal decomposition algorithm, and after compensating for the platform attitude angle deviation during the separation process based on the inertial navigation system, the phase offset angle and amplitude ratio difference of the polarization components are calculated, and a polarization direction difference parameter set is output; third, according to the communication task type, a preset covert strategy mapping table is called, the task identifiers such as reconnaissance and command transmission are converted into discrete covert levels, and after correcting the anti-interception priority coefficient in the discrete covert level by combining the number of real-time interference sources, a covert transmission requirement level parameter is generated.

[0029] 102. Generate a dynamic frequency hopping control instruction according to the time-varying characteristics of the dynamic spectrum occupancy status, and make the airborne data processing system perform carrier switching triggered by spectrum sensing between the authorized frequency band and the unauthorized frequency band through the dynamic frequency hopping control instruction, and retain the spectrum isolation area between adjacent carriers; To solve the problems of communication interruption and cross-band interference caused by untimely frequency band preemption of the airborne platform in a dynamic spectrum environment, in some embodiments, 102 includes: 1021. Extract the availability parameters of each frequency band from the dynamic spectrum occupancy status, where the availability parameters include the free time slot length of the frequency band, the interference intensity threshold, and the occupancy duration of adjacent frequency bands; 1022. Divide the frequency hopping time window according to the free time slot length of the frequency band, and perform priority sorting on the candidate frequency band sets of the authorized frequency band and the unauthorized frequency band based on the interference intensity threshold to generate a dynamic frequency hopping sequence including the frequency hopping timing and the frequency band switching rule; 1023. In the frequency hopping time window, trigger a spectrum sensing instruction according to the frequency band switching rule in the dynamic frequency hopping sequence, detect the instantaneous interference intensity of the candidate frequency band set through the spectrum sensing instruction, and generate a carrier switching action based on the detection result; 1024. Adjust the frequency band interval between the current carrier and the adjacent carrier according to the adjacent frequency band occupancy duration, so that the width of the frequency band interval meets the preset spectrum isolation zone rule, and perform a carrier switching action based on the spectrum isolation zone rule to complete the spectrum isolation zone configuration.

[0030] In this step, the availability parameter is the core index characterizing the current and future available states of the frequency band. The frequency band idle time slot length refers to the length of time that the frequency band is continuously unoccupied. The interference intensity threshold refers to the upper limit of the interference signal intensity allowed for communication. The adjacent frequency band occupancy duration refers to the cumulative time that the adjacent frequency band is occupied by other systems. The frequency hopping time window is a communication time unit divided based on the frequency band idle time slot, and the start and end times of the window are dynamically determined by the idle time slot length. The dynamic frequency hopping sequence is a set of timing instructions including the frequency hopping trigger time, the candidate frequency band priority list, and the residence duration. The spectrum isolation zone rule is a constraint condition for the width of the frequency band interval dynamically adjusted according to the adjacent frequency band occupancy state, used to avoid adjacent frequency interference.

[0031] In the embodiment of the present application, the airborne system extracts the idle time slot lengths of each frequency band from the dynamic spectrum occupancy status database, statistically calculates the historical occupancy duration of the adjacent frequency band through a sliding time window, and combines the preset interference intensity threshold to form an availability parameter set.

[0032] Divide the available frequency bands into multiple frequency hopping time windows according to the maximum value of the idle time slot length, and the window duration does not exceed the minimum value of the idle time slot to ensure the switching reliability; at the same time, perform a two-stage sorting on the candidate frequency band set based on the interference intensity threshold, first select the frequency band with the lowest interference intensity in the authorized frequency bands, and secondly the frequency band with the longest idle time slot in the unauthorized frequency bands, and generate a dynamic frequency hopping sequence after the two-stage sorting.

[0033] Trigger the spectrum sensing module at the start time of the frequency hopping time window to detect the instantaneous interference intensity of the candidate frequency band set; if the detected interference intensity exceeds the threshold, skip the current frequency band and switch to the next candidate frequency band according to the preset priority list to form a carrier switching action.

[0034] Calculate the minimum safety interval between the current carrier and the adjacent frequency band according to the adjacent frequency band occupancy duration. If the adjacent frequency band occupancy duration exceeds the preset threshold, adjust the frequency band interval to 1.5 times the minimum safety interval, otherwise maintain the default interval width to complete the spectrum isolation zone configuration after carrier switching.

[0035] The following is a specific example: Suppose that when an airborne platform performs a multi-mode satellite communication mission, the dynamic spectrum occupancy status shows that the idle slot length of the authorized frequency band A is 50 milliseconds and the interference intensity threshold is -90 dBm, the idle slot length of the unauthorized frequency band B is 80 milliseconds and the interference intensity threshold is -80 dBm, and the occupancy duration of the adjacent frequency band C is 30 milliseconds. The preset minimum safety interval is 2 MHz, and the occupancy duration threshold of the adjacent frequency band is 25 milliseconds. Step 1021 extracts the 50-millisecond idle slot of frequency band A, the interference threshold of -90 dBm, and the 30-millisecond occupancy of the adjacent frequency band C, and the 80-millisecond idle slot of frequency band B and the interference threshold of -80 dBm; Step 1022 divides the frequency hopping time window into 50 milliseconds, preferentially selects the authorized frequency band A, and generates a frequency hopping sequence of "reside in A for 50 milliseconds and then switch to B and reside for 80 milliseconds"; Step 1023 detects that the instantaneous interference intensity of frequency band A at the start moment of the window is -85 dBm, which is lower than the threshold of -90 dBm, and performs a switch to A; After 50 milliseconds, it is detected that the interference intensity of frequency band B is -75 dBm, which is higher than the threshold of -80 dBm, and B is skipped and switched to the next available frequency band according to the sequence; Step 1024 calculates that the occupancy duration of the adjacent frequency band C of 30 milliseconds exceeds the threshold of 25 milliseconds, and expands the default interval of 2 MHz between A and C to 1.5 times the minimum safety interval, that is, 3 MHz, to meet the spectrum isolation zone rule.

[0036] Steps 1021-1024 dynamically adjust the frequency band interval through the minimum safety interval threshold judgment mechanism to ensure the interference isolation ability in the high occupancy scenario of adjacent frequency bands; combined with the preset threshold and the safety interval multiple rule, realize the adaptive configuration of the spectrum isolation zone width and avoid manual intervention; the dynamic expansion of the frequency band interval effectively avoids adjacent frequency interference and ensures the continuous communication reliability of the airborne platform in the multi-band dynamic preemption environment.

[0037] Optionally, step 1022 specifically includes the following steps: divide the frequency hopping time window for the continuously available frequency bands according to the idle slot length of the frequency band, and the window duration of the frequency hopping time window does not exceed the minimum value of the idle slot lengths of the frequency bands; screen the low-interference candidate frequency bands in the authorized and unauthorized frequency bands based on the interference intensity threshold, and sort the low-interference candidate frequency bands in ascending order of the interference intensity threshold; allocate the residence duration of the corresponding frequency band to the sorted low-interference candidate frequency bands to generate a frequency band residence duration list; align the frequency hopping time window with the frequency band residence duration list along the time axis, and generate a dynamic frequency hopping sequence including the frequency hopping time sequence, the frequency band identifier, and the residence duration in combination with the silent period of the frequency hopping time window.

[0038] In the embodiments of the present application, first, the maximum allowable duration of the frequency hopping time window is determined according to the minimum value of the length of the idle time slot in the frequency band. For example, if the shortest idle time slot among all available frequency bands is 20 milliseconds, then the duration of each window does not exceed 20 milliseconds, ensuring that the frequency band switching after window division does not exceed the idle period. Secondly, candidate frequency bands with interference intensity lower than the threshold are respectively screened from the authorized frequency band and the unauthorized frequency band based on the interference intensity threshold. For example, the threshold of the authorized frequency band is set to -90 dBm and the unauthorized frequency band is set to -80 dBm. The frequency bands with interference intensity lower than the corresponding threshold are marked as low-interference candidate frequency bands, and the screened low-interference candidate frequency bands are sorted in ascending order according to the interference intensity threshold. For example, the frequency band with an interference intensity of -95 dBm in the authorized frequency band has a higher priority than the frequency band with -92 dBm, and the same applies to the unauthorized frequency band. Then, the residence duration is allocated according to the proportional relationship of the length of the idle time slot in each frequency band. For example, a longer residence duration is allocated to the frequency band with a longer idle time slot, forming a frequency band residence duration list. For example, the frequency band with an idle time slot of 50 milliseconds is allocated a residence duration of 30 milliseconds. Finally, the start time of the frequency hopping time window is aligned with the frequency band residence duration list along the time axis, and a silent period is inserted between adjacent aligned time windows to avoid signal overlap, and the frequency hopping timing, frequency band identifier, and residence duration are integrated to generate a dynamic frequency hopping sequence.

[0039] 103. Based on the polarization direction difference, the carrier switching result is subjected to orthogonal polarization diversity analysis by the airborne data processing system to eliminate the cross-polarization interference component in the same frequency band of the spectrum isolation area, and multiple baseband signals are output according to the diversity analysis result; In order to solve the problem of cross-polarization interference in the same frequency band caused by the polarization direction difference after dynamic spectrum switching on the airborne platform, in some embodiments, 103 includes: 1031. Extract the polarization reception parameters of each satellite node according to the polarization direction difference, where the polarization reception parameters include the polarization angle deviation amount, the orthogonal polarization signal strength ratio, and the cross-polarization interference amplitude; 1032. Based on the polarization angle deviation amount, the carrier switching result is subjected to orthogonal polarization decomposition by the airborne data processing system. The orthogonal polarization decomposition process decomposes each carrier signal into a horizontal polarization component and a vertical polarization component, and records the time-frequency domain distribution characteristics of each component; 1033. Adjust the synthesis weight of the horizontal polarization component and the vertical polarization component according to the orthogonal polarization signal strength ratio, and at the same time use the cross-polarization interference amplitude to perform inverse-phase superposition cancellation on the residual interference components in the same frequency band to generate an orthogonal polarization signal pair; 1034. Construct a polarization synthesis rule based on the orthogonal polarization signal pair and the time-frequency domain distribution characteristics, and synthesize the horizontal polarization component and the vertical polarization component into multiple baseband signals according to the adjusted synthesis weight according to the polarization synthesis rule.

[0040] In this step, the polarization reception parameters are quantization indices characterizing the polarization characteristics of satellite signals. The polarization angle deviation is the phase angle difference between the horizontal and vertical polarization components. The orthogonal polarization signal strength ratio is the power ratio of the two polarization components. The cross-polarization interference amplitude is the interference strength from other polarization signals within the same frequency band. Orthogonal polarization decomposition is the process of separating the received mixed signal into horizontal and vertical polarization components, while preserving the time-frequency domain energy distribution characteristics of each component. In-phase superposition cancellation is to generate a cancellation signal with a phase opposite to that of the interference signal, and after superposition, the residual interference component is eliminated. The polarization synthesis rule is a constraint condition for dynamically adjusting the synthesis ratio and phase relationship of the horizontal and vertical polarization components according to the time-frequency domain distribution characteristics.

[0041] In the embodiment of the present application, the airborne system receives the satellite signal after carrier switching through a polarization-sensitive array antenna. First, based on the real-time attitude angle data provided by the inertial navigation system, the polarization angle offset caused by the movement of the airborne platform is compensated to obtain an accurate polarization angle deviation; subsequently, an orthogonal mixer is used to separate the horizontal polarization channel and the vertical polarization channel of the signal, and the amplitude ratio of the two is calculated as the orthogonal polarization signal strength ratio; finally, the peak amplitude of the cross-polarization interference signal within the same frequency band of the satellite signal is extracted through a bandpass filter bank to obtain the cross-polarization interference amplitude parameter, and finally the polarization reception parameters are formed.

[0042] Adjust the phase response of the orthogonal polarization decomposition filter bank according to the polarization angle deviation. Input the received carrier signal into the horizontal polarization filter and the vertical polarization filter, and respectively output the horizontal polarization component and the vertical polarization component according to the adjusted phase response; perform time-frequency analysis on the two decomposed components, and use a sliding time window to record the instantaneous frequency distribution and energy concentration region of each component as the time-frequency domain distribution characteristics.

[0043] Dynamically calculate the synthesis weight coefficients of the horizontal and vertical components based on the orthogonal polarization signal strength ratio. When the strength of the horizontal component is high, the weight coefficient is increased proportionally; at the same time, generate an in-phase cancellation signal according to the cross-polarization interference amplitude. The in-phase cancellation signal converts the interference amplitude value into a complex form and then takes the conjugate phase, and is superimposed on the corresponding position in the same frequency band of the original signal to eliminate the residual interference component, and finally generate an orthogonal polarization signal pair containing the horizontal and vertical components.

[0044] Combined with the energy concentration region information in the time-frequency domain distribution characteristic matrix, construct a polarization synthesis rule: in the energy concentration region, merge the corresponding components with the maximum weight coefficient, and synthesize proportionally and evenly in the energy dispersion region; according to this rule, perform phase alignment and delay compensation on the horizontal and vertical components, and synthesize them into multiple baseband signals according to the adjusted synthesis weight coefficients.

[0045] The following is a specific example: Assume that when the airborne platform receives the signals of the low-earth orbit satellite X and the geostationary orbit satellite Y simultaneously, the polarization angle deviation of satellite X is 25 degrees, the orthogonal polarization signal strength ratio is horizontal:vertical = 3:1, and the cross-polarization interference amplitude is -78 dBm; the polarization angle deviation of satellite Y is 10 degrees, the orthogonal polarization signal strength ratio is 1:2, and the interference amplitude is -88 dBm. In step 1031, after compensating for the attitude angle deviation, the phase difference between the horizontal and vertical components of satellite X is measured to be 25 degrees, and the amplitude ratio is 3:1. The peak value of the cross-interference in the same frequency band, -78 dBm, is extracted; in step 1032, an orthogonal filter with a phase compensation of 25 degrees is configured for satellite X, and the horizontal component with the main energy concentrated in 8-10 MHz and the vertical component with the energy dispersed in 6-12 MHz are decomposed, and the time-frequency energy distribution is recorded; step 1033: Set the horizontal component weight to 0.75 and the vertical component weight to 0.25 according to the ratio of 3:1, generate a -78 dBm cancellation signal with opposite phases, and eliminate the interference in the same frequency band of satellite X; step 1034: Synthesize the horizontal component with a weight of 0.75 in the 8-10 MHz frequency band, and evenly synthesize in other regions of 6-12 MHz, and output the baseband signal of satellite X; perform the same process on satellite Y and output the baseband signal of satellite Y.

[0046] Steps 1031-1034 accurately separate the horizontal / vertical polarization signal components through dynamic polarization angle compensation and orthogonal decomposition; based on the adaptive synthesis rule of time-frequency energy distribution, optimize the merging efficiency of multi-component signals; the anti-phase cancellation technology effectively eliminates the cross-interference in the same frequency band, significantly improves the signal-to-noise ratio and integrity of the baseband signal, and meets the high-reliability transmission requirements in the airborne multi-mode satellite communication scenario.

[0047] Optionally, step 1033 specifically includes the following steps: Calculate the synthesis ratio coefficient of the horizontal polarization component and the vertical polarization component according to the orthogonal polarization signal strength ratio, and generate a weighted polarization component based on the synthesis ratio coefficient; Generate an anti-phase cancellation signal with the opposite phase to the residual interference component according to the cross-polarization interference amplitude, and superimpose the anti-phase cancellation signal and the weighted polarization component; Perform time-frequency domain energy equalization processing on the superimposed signal, and the energy equalization process eliminates the delay spread component of the residual interference component in the same frequency band to generate an intermediate polarization signal; Align the phases of the orthogonal components of the intermediate polarization signal according to the preset time-frequency synchronization rule to generate an orthogonal polarization signal pair.

[0048] In the embodiments of the present application, first, the power ratio of the horizontal polarization component and the vertical polarization component is calculated according to the orthogonal polarization signal intensity ratio, and the power ratio is converted into a synthesis proportionality coefficient. For example, when the intensity of the horizontal component is twice that of the vertical component, the synthesis proportionality coefficient is set to 0.67 for the horizontal and 0.33 for the vertical. Second, the horizontal and vertical polarization components are weighted and superimposed based on the synthesis proportionality coefficient to generate a weighted polarization component. For example, the horizontal component is multiplied by 0.67, the vertical component is multiplied by 0.33, and then added together. Third, an anti-phase cancellation signal is generated according to the cross-polarization interference amplitude. Specifically, the interference amplitude value is converted into a complex form and then the conjugate phase is taken. For example, when the interference amplitude is -80 dBm, the corresponding complex form is 0.1∠180°, and after inverting the phase, it becomes 0.1∠0°, and it is superimposed on the weighted polarization component to cancel the residual interference. Subsequently, the energy equalization processing in the time-frequency domain is performed on the superimposed signal. The time-delay spread component is suppressed by the time-frequency window function, and the gain is reduced in the frequency band with obvious time-delay spread to generate an intermediate polarization signal. Finally, the phases of the horizontal and vertical components of the intermediate polarization signal are aligned according to the preset time-frequency synchronization rule, and the phase of the vertical component is adjusted to be consistent with the horizontal component at the starting moment of the time-frequency grid to generate an orthogonal polarization signal pair.

[0049] 104. Based on the covert transmission requirement level, call the preset waveform modulation parameter library to determine the parameter set of the weighted fractional Fourier transform, and load the multi-channel baseband signals to the sub-carrier set with asymmetric phase characteristics according to the parameter set to generate a covert modulation waveform; To solve the problems of easy interception and easy interference in airborne satellite communication due to the strong regularity of the time-frequency characteristics of signals, in some embodiments, 104 includes: 1041. According to the discretization level identifier corresponding to the covert transmission requirement level, match the parameter combination of the fractional order transform from the preset waveform modulation parameter library, and the parameter combination includes a phase rotation sequence and an order factor; 1042. Decompose the phase rotation sequence into a plurality of non-uniformly distributed phase rotation amounts, and calculate the phase weight coefficients of each sub-carrier in the sub-carrier set that have a non-linear mapping relationship with the phase rotation amount based on the order factor; 1043. Allocate the multi-channel baseband signals to the sub-carrier set according to a preset ratio, perform phase rotation and superposition on the allocated baseband signals according to the phase weight coefficients of each sub-carrier in the sub-carrier set, and generate a sub-carrier unit according to the superposition result; 1044. Interleave and arrange the sub-carrier units in the time-frequency domain, and perform a phase synchronization operation on the arranged sub-carrier units according to the timing rule of the phase rotation sequence to generate a covert modulation waveform with spectrum diffusion.

[0050] In this step, the phase rotation sequence is a sequence of non-uniformly distributed phase change values used to control the phase offset rule of subcarrier signals. The order factor is the core parameter that determines the non-linear relationship between the phase rotation amount and the subcarrier weight coefficient. The non-linear mapping relationship is an exponential or polynomial function relationship established between the phase weight coefficient and the phase rotation amount through the order factor. The time-frequency domain interleaved arrangement distributes subcarrier units discontinuously on the time-frequency resource grid, breaking the signal regularity.

[0051] In the embodiment of the present application, according to the discretization level identifier corresponding to the covert transmission requirement level, where level 5 represents the highest covertness and level 1 represents the lowest covertness; retrieve the parameter combination entry bound to this level in the pre-set waveform modulation parameter library, and extract the phase rotation sequence and the corresponding order factor defined in the parameter combination entry.

[0052] Adopting an arithmetic progression or random interval distribution, the phase rotation sequence is split into multiple phase rotation amounts according to a pre-set non-uniform interval rule; based on the order factor, a non-linear mapping function is constructed for each subcarrier, and the phase rotation amount is input into the non-linear mapping function to calculate the phase weight coefficient. The phase weight coefficient is specifically the product of the power of the phase rotation amount and the order factor, such that the weight coefficient increases exponentially with the increase of the phase rotation amount.

[0053] Determine the allocation ratio according to the priority of multiple baseband signals, where high-priority signals are allocated to subcarriers with large weight coefficients; apply a phase rotation superposition operation to the baseband signal of each subcarrier. The phase rotation superposition operation is that the complex form of the baseband signal is multiplied by the rotation factor corresponding to the phase weight coefficient, and finally the superimposed subcarrier unit is generated.

[0054] Map the subcarrier units to discrete time-frequency resource blocks according to the time-frequency interleaving template, and the time-frequency interleaving template is generated by a pseudo-random sequence; according to the timing rule of the phase rotation sequence, apply a phase synchronization offset to the subcarrier units of adjacent time-frequency resource blocks to ensure that the initial phase difference between adjacent units is consistent with the timing change of the phase rotation sequence, and finally generate a spectrally diffused covert modulation waveform.

[0055] The following is a specific example: Suppose that when the airborne platform performs high-concealment reconnaissance missions, the concealment transmission requirement level is 5, and the corresponding phase rotation sequences in the parameter library are 45°, 135°, 225°, 45°, 135°, 225°, and the order factor is 3.0. Step 1041 matches level 5 to obtain the phase rotation sequences 45°, 135°, 225°, 45°, 135°, 225° and the order factor 3.0; Step 1042 decomposes the sequence into three non-uniform phase rotation amounts 45°, 135°, 225°, and calculates the subcarrier weight coefficients according to the non-linear function. For example, the weight of subcarrier 1 = 45° × 3.0³ = 1215°; Step 1043 distributes the reconnaissance data baseband signal to the three subcarriers according to the ratio of 2:1:1, and applies phase rotations of 1215°, 3645°, and 6075° respectively to generate subcarrier units; Step 1044 distributes the subcarrier units at positions such as time slot 1 - frequency point 3, time slot 2 - frequency point 5 according to the pseudo-random time-frequency template, and synchronizes the phase difference between adjacent units to be 90° to generate a concealed modulation waveform.

[0056] Steps 1041 - 1044 break the regularity of the signal phase change through non-uniform phase rotation decomposition and non-linear weight mapping; the time-frequency interleaving and phase synchronization mechanism further diffuses the signal energy distribution, reducing the probability of the enemy's detection equipment identifying the time-frequency characteristics; the dynamic parameter adaptation driven by the concealment level ensures the anti-interception and anti-jamming capabilities in different mission scenarios.

[0057] 105. Input the dynamic frequency hopping control instruction and the frequency spectrum spreading range of the concealed modulation waveform into the fusion control module of the airborne data processing system, and then output a cooperative modulation instruction, and control the airborne radio frequency unit to achieve multi-mode satellite data anti-jamming fusion transmission in a dynamic spectrum sharing environment through the cooperative modulation instruction.

[0058] To solve the problems of spectrum resource conflict and decreased anti-jamming ability caused by the lack of coordination between dynamic frequency hopping and concealed waveform modulation in airborne multi-mode satellite communication, in some embodiments, 105 includes: 1051. Analyze the frequency hopping timing parameters and frequency band residence duration in the dynamic frequency hopping control instruction, and extract the frequency coverage interval corresponding to the frequency spectrum spreading range of the concealed modulation waveform; 1052. Adjust the subcarrier phase distribution parameters of the concealed modulation waveform according to the overlapping relationship between the frequency hopping timing parameters and the frequency coverage interval to generate cooperative modulation parameters synchronized with frequency hopping; 1053. Match the frequency band residence duration with the time-frequency resource allocation ratio of the cooperative modulation parameters, and calculate the power allocation coefficient of the airborne radio frequency unit in each frequency band according to the matching degree; 1054. Dynamically weight the collaborative modulation parameters into a collaborative modulation instruction according to the power distribution coefficient, and control the airborne radio frequency unit to perform multi-mode satellite data anti-jamming fusion transmission through the collaborative modulation instruction.

[0059] In this step, the frequency hopping timing parameters are the frequency hopping trigger moment, the target frequency band identifier, and the dwell duration sequence defined in the dynamic frequency hopping control instruction. The frequency coverage range is the energy diffusion range of the covert modulation waveform in the frequency domain, including the start frequency, the cut-off frequency, and the center frequency point. The collaborative modulation parameters are modulation control parameters that integrate the frequency hopping timing and the spectral characteristics of the covert waveform, including the sub-carrier phase offset and the time-frequency resource block allocation rule. The power distribution coefficient is a radio frequency transmission power ratio parameter dynamically allocated according to the frequency band dwell duration and the interference intensity.

[0060] In the embodiment of the present application, the airborne data processing system analyzes the frequency hopping trigger moment list in the dynamic frequency hopping control instruction, extracts the target frequency band identifier and its dwell duration corresponding to each trigger moment; synchronously calls the spectrum analysis module to perform a fast Fourier transform on the covert modulation waveform, locates the start frequency and the cut-off frequency of its spectral energy, and generates the frequency coverage range parameters.

[0061] Compare the center frequency of the target frequency band in the frequency hopping timing parameters with the frequency coverage range of the covert waveform. If the target frequency band is completely within the coverage range, keep the sub-carrier phase distribution parameters unchanged; if the target frequency band partially exceeds the coverage range, reduce the sub-carrier phase rotation step according to the exceeding ratio. For example, if the part outside the coverage range accounts for 30%, then reduce the phase step to 70% of the original value, and generate a list of phase offsets for frequency hopping synchronization; bind the list of phase offsets to the frequency hopping timing parameters to form collaborative modulation parameters.

[0062] Take the ratio of the frequency band dwell duration to the total communication duration as the basic matching degree of the time-frequency resource allocation ratio. For example, if the dwell duration of frequency band A accounts for 30% of the total duration, the matching degree is 0.3; allocate the number of time-frequency resource blocks according to the matching degree in proportion. For example, the matching degree of 0.3 corresponds to 30% of the resource blocks; generate an interference intensity factor based on the real-time interference intensity detection value. The interference intensity factor is equal to the ratio of the current frequency band interference intensity to the preset maximum interference intensity. Multiply the matching degree by the interference intensity factor to obtain the power distribution coefficient. For example, the matching degree of 0.3 × the interference factor of 0.8 = the power distribution coefficient of 0.24.

[0063] Perform weighted fusion of the power coefficients in the power distribution table and the phase offsets in the collaborative modulation parameters band by band. After weighting, the phase offset is adjusted to the product of the power coefficient and the phase offset; generate a collaborative modulation instruction including the frequency band identifier, the phase offset, and the power threshold according to the weighted result, and send it to the radio frequency unit for execution.

[0064] The following is a specific example: Suppose that when the airborne platform is performing multimode satellite communication tasks, the dynamic frequency hopping control instruction requires that frequency band A switch to 2.0 GHz in time slots 0 - 50 milliseconds and dwell for 50 milliseconds; frequency band B switch to 2.1 GHz in time slots 60 - 100 milliseconds and dwell for 40 milliseconds), and the total communication duration is 100 milliseconds. The spectrum spreading range of the covert modulation waveform is from 1.95 GHz to 2.15 GHz. The real-time detected interference intensity of frequency band A is -75 dBm, the preset maximum interference is -70 dBm, and the interference intensity of frequency band B is -80 dBm. In step 1051, the frequency hopping trigger time list is parsed to extract the dwell duration of frequency band A as 50 milliseconds and the dwell duration of frequency band B as 40 milliseconds; the frequency coverage range of the covert waveform is determined to be 1.95 GHz - 2.15 GHz through spectrum analysis; in step 1052, the center frequency of frequency band A, 2.0 GHz, is completely within the range of 1.95 - 2.15 GHz, and the subcarrier phase step is maintained at 15°; the center frequency of frequency band B, 2.1 GHz, partially exceeds the upper limit of the coverage range, 2.15 GHz (the exceeding ratio is 25%), and the phase step is reduced to 15° × 75% = 11.25°. A phase offset list is generated, and the phase offset list is bound to the frequency hopping timing parameters to form cooperative modulation parameters; in step 1053, the matching degree of frequency band A = 50 / 100 = 0.5, and 50% of the time-frequency resource blocks are allocated; the interference factor = (-75 + 70) / 10 = 0.5, and the power coefficient = 0.5 × 0.5 = 0.25 (adjusted to 0.4 after normalization); the matching degree of frequency band B = 40 / 100 = 0.4, and 40% of the resource blocks are allocated; the interference factor = (-80 + 70) / 10 = 1.0, and the power coefficient = 0.4 × 1.0 = 0.4 (adjusted to 0.6 after normalization); in step 1054, the cooperative modulation parameter of frequency band A is 15° × 0.4 = 6°, and that of frequency band B is 11.25° × 0.6 = 6.75°. An instruction is generated to control the radio frequency unit to transmit signals according to these parameters.

[0065] Steps 1051 - 1054 ensure that the signal energy is accurately concentrated within the target frequency band through the dynamic matching adjustment of the frequency hopping band and the spectrum coverage of the covert waveform, avoiding spectrum leakage; based on the quantization matching mechanism of the dwell duration and the interference intensity, an objective calculation of the power distribution coefficient is realized, enabling a higher transmission power to be obtained in high-interference frequency bands; the cooperative optimization of the time-frequency resource allocation ratio and the phase offset significantly improves the spectrum resource utilization efficiency and anti-interference ability, ensuring the continuous and reliable transmission of airborne multimode satellite data in a dynamic spectrum environment.

[0066] Suppose an airborne platform needs to communicate with a low-earth orbit satellite Gamma, a medium-earth orbit satellite Delta, and a geostationary orbit satellite Epsilon simultaneously. The polarization direction deviation of Gamma is 25 degrees and the concealment requirement level is 4; the polarization deviation of Delta is 15 degrees and the concealment level is 3; the polarization deviation of Epsilon is 40 degrees and the concealment level is 5. The dynamic spectrum shows that the authorized frequency band C is 2.2 GHz - 2.3 GHz, idle for 60 milliseconds, and the interference threshold is -95 dBm; the unlicensed frequency band D is 2.4 GHz - 2.5 GHz, idle for 40 milliseconds, and the interference threshold is -85 dBm; the adjacent frequency band E is 2.35 GHz, occupied for 50 milliseconds. Step 101 obtains the real-time parameters of Gamma, Delta, and Epsilon: the idle duration and interference threshold of frequency bands C / D, and the polarization amplitude ratios are 3:1, 1:1, and 4:1 respectively, and the concealment levels are 4 / 3 / 5. Step 102 divides the 60-millisecond idle time of frequency band C into 40-millisecond frequency hopping windows with a silent interval of 5 milliseconds; after priority sorting, a sequence "C dwells for 40 ms → D dwells for 30 ms" is generated; since frequency band E is occupied beyond the threshold, the interval between C and E is expanded to 3 MHz. Step 103 decomposes the Gamma signal into a 75% horizontal component and a 25% vertical component, generates an anti-phase signal to eliminate -80 dBm interference; Delta is synthesized according to a 1:1 weight and Epsilon is synthesized according to a 4:1 weight, and three baseband signals are output. In Step 104, Epsilon calls the phase sequences 45° / 135° / 225° and the order factor 3.0, calculates the subcarrier weights 1215° / 3645° / 6075°, and allocates and loads the baseband signals according to a 2:1:1 ratio to generate a 2.1 - 2.6 GHz spread waveform. In Step 105, the phase step of frequency band C is 15°, and the out-of-range part of D is reduced to 12°; the power coefficients C 0.6 and D 0.4 are allocated according to the dwell duration, and the radio frequency transmission is controlled through a cooperative instruction.

[0067] Steps 101 - 105 achieve the real-time and efficient utilization of multi-band resources through a dynamic spectrum preemption and adaptive frequency hopping mechanism; the orthogonal polarization diversity analysis and anti-phase cancellation technology effectively suppress the co-frequency cross-interference and improve the signal quality; the asymmetric phase modulation and time-frequency interleaving significantly enhance the signal concealment and reduce the interception probability; the cooperative control module integrates the frequency hopping and concealment parameters to ensure the anti-interference and reliable transmission of multi-mode satellite data in a complex electromagnetic environment, meeting the requirements of high real-time and high concealment.

[0068] Figure 2 The following is a schematic structural diagram of a heterogeneous data fusion transmission system for airborne multi-mode satellite communication provided by an embodiment of the present application, as Figure 2 shown. The system includes: An acquisition module 21, configured to acquire real-time communication parameters between an airborne data processing system and multiple satellite nodes, where the real-time communication parameters include the dynamic spectrum occupancy status, polarization direction difference, and covert transmission requirement level of each satellite node; An execution module 22, configured to generate a dynamic frequency hopping control instruction according to the time-varying characteristics of the dynamic spectrum occupancy status, and cause the airborne data processing system to perform spectrum sensing-triggered carrier switching between authorized frequency bands and unauthorized frequency bands through the dynamic frequency hopping control instruction, and reserve a spectrum isolation area between adjacent carriers; An output module 23, configured to perform orthogonal polarization diversity analysis on the carrier switching result through the airborne data processing system based on the polarization direction difference, so as to eliminate the cross-polarization interference component within the same frequency band of the spectrum isolation area, and output multiple baseband signals according to the diversity analysis result; A generation module 24, configured to determine a parameter set of weighted fractional Fourier transform based on the covert transmission requirement level by invoking a preset waveform modulation parameter library, and load the multiple baseband signals to a sub-carrier set with asymmetric phase characteristics according to the parameter set to generate a covert modulation waveform; A control module 25, configured to input the dynamic frequency hopping control instruction and the spectrum spreading range of the covert modulation waveform into a fusion control module of the airborne data processing system, and then output a collaborative modulation instruction, and control an airborne radio frequency unit to achieve multi-mode satellite data anti-interference fusion transmission in a dynamic spectrum sharing environment through the collaborative modulation instruction.

[0069] Figure 2 The described heterogeneous data fusion transmission system for airborne multi-mode satellite communication can execute Figure 1 The heterogeneous data fusion transmission method for airborne multi-mode satellite communication described in the embodiments shown, and its implementation principle and technical effects will not be elaborated. For the heterogeneous data fusion transmission system for airborne multi-mode satellite communication in the above embodiments, the specific manners in which each module and unit perform operations have been described in detail in the embodiments related to the method, and will not be elaborated here.

[0070] In a possible design, Figure 2 The heterogeneous data fusion transmission system for airborne multi-mode satellite communication described in the embodiments shown can be implemented as a computing device, such as Figure 3 shown, and the computing device can include a storage component 31 and a processing component 32; The storage component 31 stores one or more computer instructions, where the one or more computer instructions are called and executed by the processing component 32.

[0071] The processing component 32 is used for the above Figure 1A heterogeneous data fusion transmission method for airborne multi-mode satellite communication according to the above-mentioned embodiment.

[0072] Among them, the processing component 32 may include one or more processors to execute computer instructions to complete all or part of the steps in the above-mentioned method. Of course, the processing component can also be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors or other electronic components for executing the above-mentioned method.

[0073] The storage component 31 is configured to store various types of data to support the operation of the terminal. The storage component can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk.

[0074] Of course, the computing device may also necessarily include other components, such as input / output interfaces, display components, communication components, etc.

[0075] The input / output interface provides an interface between the processing component and the peripheral interface module, and the above-mentioned peripheral interface module can be an output device, an input device, etc.

[0076] The communication component is configured to facilitate communication between the computing device and other devices in a wired or wireless manner, etc.

[0077] Among them, the computing device can be a physical device or an elastic computing host provided by a cloud computing platform, etc. At this time, the computing device can refer to a cloud server, and the above-mentioned processing component, storage component, etc. can be basic server resources rented or purchased from a cloud computing platform.

[0078] The embodiment of the present application also provides a computer storage medium storing a computer program, and when the computer program is executed by a computer, it can implement the above-mentioned Figure 1 A heterogeneous data fusion transmission method for airborne multi-mode satellite communication according to the above-mentioned embodiment.

[0079] Those skilled in the art can clearly understand that for the convenience and conciseness of description, the specific working processes of the above-described systems, devices, and units can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein.

[0080] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative efforts.

[0081] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment 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 essence of the above technical solution or the part that contributes to the prior art can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions for causing a computer device (which can be a personal computer, server, or network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of each embodiment of the present application.

Claims

1. A heterogeneous data fusion transmission method for airborne multi-mode satellite communication, characterized in that, Including: Obtaining real-time communication parameters between an airborne data processing system and multiple satellite nodes, where the real-time communication parameters include the dynamic spectrum occupancy status, polarization direction difference, and covert transmission requirement level of each satellite node; Generating a dynamic frequency hopping control instruction according to the time-varying characteristics of the dynamic spectrum occupancy status, and enabling the airborne data processing system to perform spectrum sensing-triggered carrier switching between the authorized frequency band and the unauthorized frequency band through the dynamic frequency hopping control instruction, and reserving a spectrum isolation area between adjacent carriers; Based on the polarization direction difference, performing orthogonal polarization diversity analysis on the carrier switching result through the airborne data processing system to eliminate the cross-polarization interference component in the same frequency band of the spectrum isolation area, and outputting multiple baseband signals according to the diversity analysis result; Based on the covert transmission requirement level, calling a preset waveform modulation parameter library to determine a parameter set of weighted fractional Fourier transform, and loading the multiple baseband signals to a subcarrier set with an asymmetric phase characteristic according to the parameter set to generate a covert modulation waveform; Inputting the dynamic frequency hopping control instruction and the spectrum spreading range of the covert modulation waveform into the fusion control module of the airborne data processing system and then outputting a cooperative modulation instruction, and controlling the airborne radio frequency unit to achieve multi-mode satellite data anti-interference fusion transmission in a dynamic spectrum sharing environment through the cooperative modulation instruction.

2. The method according to claim 1, characterized in that, The step of, based on the covert transmission requirement level, calling a preset waveform modulation parameter library to determine a parameter set of weighted fractional Fourier transform, and loading the multiple baseband signals to a subcarrier set with an asymmetric phase characteristic according to the parameter set to generate a covert modulation waveform, includes: Matching a parameter combination of fractional order transform from a preset waveform modulation parameter library according to the discretization level identifier corresponding to the covert transmission requirement level, where the parameter combination includes a phase rotation sequence and an order factor; Decomposing the phase rotation sequence into multiple non-uniformly distributed phase rotation amounts, and calculating a phase weight coefficient of each subcarrier in the subcarrier set that has a non-linear mapping relationship with the phase rotation amount based on the order factor; Allocating the multiple baseband signals to the subcarrier set according to a preset ratio, performing phase rotation superposition on the allocated baseband signals according to the phase weight coefficient of each subcarrier in the subcarrier set, and generating a subcarrier unit according to the superposition result; Performing interleaved arrangement on the subcarrier unit in the time-frequency domain, and performing phase synchronization operation on the arranged subcarrier unit according to the timing rule of the phase rotation sequence to generate a spectrum-spread covert modulation waveform.

3. The method according to claim 1, wherein The step of generating a dynamic frequency hopping control instruction according to the time-varying characteristics of the dynamic spectrum occupancy status, and enabling the airborne data processing system to perform spectrum sensing-triggered carrier switching between the authorized frequency band and the unauthorized frequency band through the dynamic frequency hopping control instruction, and reserving a spectrum isolation area between adjacent carriers, includes: Extracting availability parameters of each frequency band from the dynamic spectrum occupancy status, where the availability parameters include the length of the idle time slot of the frequency band, the interference intensity threshold, and the occupancy duration of the adjacent frequency band; Divide the frequency hopping time window according to the length of the idle time slot of the frequency band, and prioritize the candidate frequency band sets of the authorized frequency band and the unlicensed frequency band based on the interference intensity threshold to generate a dynamic frequency hopping sequence including frequency hopping timing and frequency band switching rules; Within the frequency hopping time window, trigger a spectrum sensing instruction according to the frequency band switching rule in the dynamic frequency hopping sequence, detect the instantaneous interference intensity of the candidate frequency band set through the spectrum sensing instruction, and generate a carrier switching action based on the detection result; Adjust the frequency band interval between the current carrier and the adjacent carrier according to the occupancy duration of the adjacent frequency band, so that the width of the frequency band interval meets the preset spectrum isolation area rule, and perform a carrier switching action based on the spectrum isolation area rule to complete the spectrum isolation area configuration.

4. The method according to claim 1, wherein Based on the polarization direction difference, perform orthogonal polarization diversity analysis on the carrier switching result through the airborne data processing system to eliminate the cross-polarization interference component in the same frequency band of the spectrum isolation area, and output multi-channel baseband signals according to the diversity analysis result, including: Extract the polarization reception parameters of each satellite node according to the polarization direction difference, and the polarization reception parameters include polarization angle deviation, orthogonal polarization signal strength ratio, and cross-polarization interference amplitude; Based on the polarization angle deviation, perform orthogonal polarization decomposition on the carrier switching result through the airborne data processing system. The orthogonal polarization decomposition process decomposes each carrier signal into a horizontal polarization component and a vertical polarization component, and records the time-frequency domain distribution characteristics of each component; Adjust the synthesis weight of the horizontal polarization component and the vertical polarization component according to the orthogonal polarization signal strength ratio, and at the same time use the cross-polarization interference amplitude to perform inverse-phase superposition cancellation on the residual interference components in the same frequency band to generate an orthogonal polarization signal pair; Construct a polarization synthesis rule based on the orthogonal polarization signal pair and the time-frequency domain distribution characteristics, and synthesize the horizontal polarization component and the vertical polarization component into multi-channel baseband signals according to the adjusted synthesis weight according to the polarization synthesis rule.

5. The method according to claim 3, wherein The method of dividing the frequency hopping time window according to the length of the idle time slot of the frequency band, and prioritizing the candidate frequency band sets of the authorized frequency band and the unlicensed frequency band based on the interference intensity threshold to generate a dynamic frequency hopping sequence including frequency hopping timing and frequency band switching rules includes: Divide the continuous available frequency band into frequency hopping time windows according to the length of the idle time slot of the frequency band, and the window duration of the frequency hopping time window does not exceed the minimum value of the length of the idle time slot of the frequency band; Screen the low-interference candidate frequency bands in the authorized and unlicensed frequency bands based on the interference intensity threshold, and prioritize the low-interference candidate frequency bands from low to high according to the interference intensity threshold; Allocate the residence duration of the corresponding frequency band to the sorted low-interference candidate frequency bands to generate a frequency band residence duration list; Align the frequency hopping time window and the frequency band residence duration list along the time axis, and combine the silent period of the frequency hopping time window to generate a dynamic frequency hopping sequence including frequency hopping timing, frequency band identification, and residence duration.

6. The method according to claim 4, wherein Adjusting the synthesis weights of the horizontal polarization component and the vertical polarization component according to the orthogonal polarization signal intensity ratio, and simultaneously using the cross-polarization interference amplitude to perform inverse superposition cancellation on the residual interference components within the same frequency band to generate an orthogonal polarization signal pair, including: Calculating the synthesis ratio coefficient of the horizontal polarization component and the vertical polarization component according to the orthogonal polarization signal intensity ratio, and generating a weighted polarization component based on the synthesis ratio coefficient; Generating an inverse cancellation signal with a phase opposite to that of the residual interference component according to the cross-polarization interference amplitude, and superimposing the inverse cancellation signal and the weighted polarization component; Performing time-frequency domain energy equalization processing on the superimposed signal, and the energy equalization processing process eliminates the delay spread component of the residual interference component within the same frequency band to generate an intermediate polarization signal; Aligning the phase of the orthogonal components of the intermediate polarization signal according to a preset time-frequency synchronization rule to generate an orthogonal polarization signal pair.

7. The method according to claim 1, wherein Inputting the dynamic frequency hopping control instruction and the spectrum spreading range of the covert modulation waveform into the fusion control module of the airborne data processing system, and then outputting a collaborative modulation instruction, and controlling the airborne radio frequency unit to achieve multi-mode satellite data anti-interference fusion transmission in a dynamic spectrum sharing environment through the collaborative modulation instruction, including: Analyzing the frequency hopping timing parameters and the frequency band residence duration in the dynamic frequency hopping control instruction, and extracting the frequency coverage interval corresponding to the spectrum spreading range of the covert modulation waveform; Adjusting the sub-carrier phase distribution parameters of the covert modulation waveform according to the overlapping relationship between the frequency hopping timing parameters and the frequency coverage interval to generate frequency hopping synchronized collaborative modulation parameters; Matching the frequency band residence duration with the time-frequency resource allocation ratio of the collaborative modulation parameters, and calculating the power distribution coefficient of the airborne radio frequency unit in each frequency band according to the matching degree; Dynamically weighting the collaborative modulation parameters into a collaborative modulation instruction according to the power distribution coefficient, and controlling the airborne radio frequency unit to perform multi-mode satellite data anti-interference fusion transmission through the collaborative modulation instruction.

8. A heterogeneous data fusion and transmission system for airborne multi-mode satellite communication, characterized in that Including: An acquisition module, configured to acquire real-time communication parameters between the airborne data processing system and multiple satellite nodes, where the real-time communication parameters include the dynamic spectrum occupancy status, polarization direction difference, and covert transmission requirement level of each satellite node; An execution module, configured to generate a dynamic frequency hopping control instruction according to the time-varying characteristics of the dynamic spectrum occupancy status, and perform carrier switching triggered by spectrum sensing between the authorized frequency band and the unauthorized frequency band through the dynamic frequency hopping control instruction, and retain the spectrum isolation area between adjacent carriers; An output module, configured to perform orthogonal polarization diversity analysis on the carrier switching result through the airborne data processing system based on the polarization direction difference to eliminate the cross-polarization interference component within the same frequency band of the spectrum isolation area, and output multiple baseband signals according to the diversity analysis result; A generation module, configured to call a preset waveform modulation parameter library based on the covert transmission requirement level to determine a parameter set of the weighted fractional Fourier transform, and load the multiple baseband signals onto a sub-carrier set with asymmetric phase characteristics according to the parameter set to generate a covert modulation waveform; A control module, configured to input the dynamic frequency hopping control instruction and the spectrum spreading range of the covert modulation waveform into a fusion control module of the airborne data processing system, and then output a collaborative modulation instruction, and control an airborne radio frequency unit through the collaborative modulation instruction to achieve multi-mode satellite data anti-jamming fusion transmission in a dynamic spectrum sharing environment.

9. A computing device, characterized in that, It includes a processing component and a storage component; the storage component stores one or more computer instructions; the one or more computer instructions are used to be called and executed by the processing component to implement a heterogeneous data fusion transmission method for airborne multi-mode satellite communication according to any one of claims 1 to 7.

10. A computer storage medium, characterized in that, It stores a computer program, and when the computer program is executed by a computer, it implements a heterogeneous data fusion transmission method for airborne multi-mode satellite communication according to any one of claims 1 to 7.

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