A heterogeneous data fusion transmission method and system for airborne multi-mode satellite communications

Abstract

The present application relates to the field of data fusion transmission technology, and provides a heterogeneous data fusion transmission method and system for airborne multi-mode satellite communications. Real-time communication parameters are obtained, including dynamic spectrum occupancy status, polarization direction differences, and concealed transmission requirement levels; dynamic frequency hopping control instructions are generated based on the time-varying characteristics of the dynamic spectrum occupancy status to drive carrier switching and retain the spectrum isolation area between adjacent carriers; orthogonal polarization diversity analysis is performed on the carrier switching results based on polarization direction differences to suppress cross-polarization interference and output multi-path baseband signals; modulation parameters are determined by calling the preset waveform parameter library according to the concealed requirement level, and the baseband signal is loaded onto the asymmetric phase subcarrier to generate a concealed modulation waveform; the frequency hopping instructions are integrated with the concealed modulation waveform to generate a coordinated modulation instruction, and the radio frequency unit is controlled to achieve anti-interference fusion transmission. The technical solution provided by the present application improves the anti-interference capability of fusion transmission of multi-mode satellite data in a dynamic spectrum environment.

Description

Technical Field

[0001] The present application relates to the technical field of data fusion transmission, and in particular to a heterogeneous data fusion transmission method and system for airborne multi-mode satellite communications. Background Art

[0002] In airborne multi-mode satellite communications scenarios, aircraft must simultaneously access multiple heterogeneous satellite nodes (e.g., low-Earth orbit, medium-Earth orbit, and geostationary orbit satellites). This presents multiple challenges: dynamic spectrum resource preemption, cross-band interference mitigation, and covert transmission requirements. Due to the high-speed mobility of airborne platforms and the varying spectrum strategies of satellite nodes, it is necessary to coordinate multi-band dynamic preemption, co-channel interference mitigation, and low-rate of intercept transmission to ensure the real-time and reliable transmission of high-priority data.

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

[0004] Existing solutions have the following defects: dynamic frequency hopping relies on a fixed priority list and cannot adapt to rapid changes in spectrum occupancy status in real time, resulting in low spectrum resource utilization and significant switching delays; frequency domain filtering has difficulty eliminating cross-interference between orthogonal polarization signals in the same frequency band, especially when the polarization directions of satellite nodes differ greatly, the bit error rate rises sharply; AMC modulation parameters are fixed, and the signal time-frequency characteristics are highly regular, making them easily identified by enemy detection equipment and targeted interference. Summary of the Invention

[0005] The present application provides a heterogeneous data fusion transmission method and system for airborne multi-mode satellite communications, which is used to solve the problem of insufficient anti-interference capability of fusion transmission of multi-mode satellite data in a dynamic spectrum environment in the prior art.

[0006] In a first aspect, the present application provides a heterogeneous data fusion transmission method for airborne multi-mode satellite communications, comprising:

[0007] Acquiring real-time communication parameters between an airborne data processing system and multiple satellite nodes, wherein the real-time communication parameters include a dynamic spectrum occupancy status, polarization direction difference, and covert transmission requirement level of each satellite node;

[0008] generating a dynamic frequency hopping control instruction based on the time-varying characteristics of the dynamic spectrum occupancy state, and causing the onboard data processing system to perform spectrum sensing-triggered carrier switching between the licensed frequency band and the unlicensed frequency band through the dynamic frequency hopping control instruction, while retaining a spectrum isolation zone between adjacent carriers;

[0009] Based on the polarization direction difference, the airborne data processing system performs orthogonal polarization diversity analysis on the carrier switching result to eliminate cross-polarization interference components within the same frequency band of the spectrum isolation area, and outputs multiple baseband signals according to the diversity analysis result;

[0010] Based on the concealed transmission requirement level, calling a preset waveform modulation parameter library to determine a parameter set for weighted fractional Fourier transform, and loading the multi-channel baseband signal onto a subcarrier set with asymmetric phase characteristics according to the parameter set to generate a concealed modulation waveform;

[0011] The dynamic frequency hopping control instruction and the spectrum diffusion range of the concealed modulation waveform are input into the fusion control module of the airborne data processing system, and then a cooperative modulation instruction is output. The airborne radio frequency unit is controlled by the cooperative modulation instruction to realize anti-interference fusion transmission of multi-mode satellite data in a dynamic spectrum sharing environment.

[0012] Optionally, based on the concealed transmission requirement level, calling a preset waveform modulation parameter library to determine a parameter set for weighted fractional Fourier transform, and loading the multi-channel baseband signal onto a subcarrier set having an asymmetric phase characteristic according to the parameter set to generate a concealed modulation waveform includes:

[0013] According to the discretization level identifier corresponding to the covert transmission requirement level, matching a parameter combination of a fractional order transformation from a preset waveform modulation parameter library, the parameter combination including a phase rotation sequence and an order factor;

[0014] Decomposing the phase rotation sequence into a plurality of non-uniformly distributed phase rotation amounts, and calculating a phase weight coefficient of each subcarrier in the subcarrier set that is nonlinearly mapped to the phase rotation amount based on the order factor;

[0015] Allocating the multiple baseband signals to the subcarrier set according to a preset ratio, performing phase rotation and 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;

[0016] 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 concealed modulation waveform with spectrum diffusion.

[0017] Optionally, generating a dynamic frequency hopping control instruction based on the time-varying characteristics of the dynamic spectrum occupancy state, and causing the onboard data processing system to perform spectrum sensing-triggered carrier switching between a licensed frequency band and an unlicensed frequency band through the dynamic frequency hopping control instruction, while retaining a spectrum isolation zone between adjacent carriers, includes:

[0018] Extracting availability parameters of each frequency band from the dynamic spectrum occupancy status, the availability parameters including frequency band idle time slot length, interference intensity threshold, and adjacent frequency band occupancy duration;

[0019] 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, and generating a dynamic frequency hopping sequence including the frequency hopping timing and the frequency band switching rule;

[0020] triggering a spectrum sensing instruction according to a frequency band switching rule in the dynamic frequency hopping sequence within the frequency hopping time window, detecting instantaneous interference intensity of the candidate frequency band set through the spectrum sensing instruction, and generating a carrier switching action based on the detection result;

[0021] 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 rules, and perform carrier switching action based on the spectrum isolation zone rules to complete the spectrum isolation zone configuration.

[0022] Optionally, based on the polarization direction difference, performing orthogonal polarization diversity analysis on the carrier switching result by the airborne data processing system to eliminate cross-polarization interference components within the same frequency band of the spectrum isolation area, and outputting multiple baseband signals according to the diversity analysis result, includes:

[0023] Extracting polarization reception parameters of each satellite node according to the polarization direction difference, wherein the polarization reception parameters include polarization angle deviation, orthogonal polarization signal strength ratio, and cross-polarization interference amplitude;

[0024] Based on the polarization angle deviation, the airborne data processing system performs orthogonal polarization decomposition on the carrier switching result, wherein 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;

[0025] Adjusting the synthesis weight of the horizontal polarization component and the vertical polarization component according to the orthogonal polarization signal strength ratio, and using the cross-polarization interference amplitude to perform anti-phase superposition and offset on the residual interference components in the same frequency band to generate an orthogonal polarization signal pair;

[0026] A polarization synthesis rule is established based on the orthogonal polarization signal pair and the time-frequency domain distribution characteristics, and the horizontal polarization component and the vertical polarization component are synthesized into a multi-path baseband signal according to the polarization synthesis rule and the adjusted synthesis weight.

[0027] Optionally, dividing the frequency hopping time window according to the idle time slot length of the frequency band, and prioritizing the candidate frequency band set of the authorized frequency band and the unlicensed frequency band based on the interference intensity threshold, and generating a dynamic frequency hopping sequence including the frequency hopping timing and the frequency band switching rule, includes:

[0028] Dividing the continuous available frequency band into frequency hopping time windows according to the idle time slot length of the frequency band, wherein the window length of the frequency hopping time window does not exceed the minimum value of the idle time slot length of the frequency band;

[0029] Screening low-interference candidate frequency bands in authorized and unauthorized frequency bands based on the interference intensity threshold, and prioritizing the low-interference candidate frequency bands from low to high according to the interference intensity threshold;

[0030] Allocate dwell times of corresponding frequency bands to the sorted low-interference candidate frequency bands, and generate a frequency band dwell time list;

[0031] The frequency hopping time window is aligned with the frequency band dwell time list according to a time axis, and a dynamic frequency hopping sequence including a frequency hopping timing, a frequency band identifier and a dwell time is generated in combination with a silent period of the frequency hopping time window.

[0032] Optionally, the adjusting the combined weight of the horizontal polarization component and the vertical polarization component according to the orthogonal polarization signal strength ratio, and simultaneously using the cross-polarization interference amplitude to perform anti-phase superposition and cancellation on the residual interference component in the same frequency band to generate an orthogonal polarization signal pair includes:

[0033] Calculating a synthesis proportional coefficient of the horizontal polarization component and the vertical polarization component according to the orthogonal polarization signal strength ratio, and generating a weighted polarization component based on the synthesis proportional coefficient;

[0034] generating an anti-phase cancellation signal having a phase opposite to that of the residual interference component according to the cross-polarization interference amplitude, and superimposing the anti-phase cancellation signal with the weighted polarization component;

[0035] The superimposed signals are subjected to time-frequency domain energy equalization processing. The energy equalization process eliminates the delay spread component of the residual interference component in the same frequency band and generates an intermediate polarization signal.

[0036] The orthogonal components of the intermediate polarization signal are phase-aligned according to a preset time-frequency synchronization rule to generate an orthogonal polarization signal pair.

[0037] Optionally, the step of inputting the dynamic frequency hopping control instruction and the spectrum diffusion range of the concealed modulation waveform into a fusion control module of the airborne data processing system and outputting a coordinated modulation instruction, and controlling the airborne radio frequency unit through the coordinated modulation instruction to implement anti-interference fusion transmission of multi-mode satellite data in a dynamic spectrum sharing environment, includes:

[0038] parsing the frequency hopping timing parameters and the frequency band dwell time in the dynamic frequency hopping control instruction, and extracting the frequency coverage interval corresponding to the spectrum diffusion range of the concealed modulation waveform;

[0039] Adjusting 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 the coordinated modulation parameters for frequency hopping synchronization;

[0040] Matching the frequency band dwell time with the time-frequency resource allocation ratio of the coordinated modulation parameter, and calculating the power allocation coefficient of the carrier radio frequency unit in each frequency band according to the matching degree;

[0041] The coordinated modulation parameters are dynamically weighted into coordinated modulation instructions according to the power allocation coefficient, and the airborne radio frequency unit is controlled by the coordinated modulation instructions to perform anti-interference fusion transmission of multi-mode satellite data.

[0042] In a second aspect, the present application provides a heterogeneous data fusion transmission system for airborne multi-mode satellite communications, comprising:

[0043] an acquisition module, configured to acquire real-time communication parameters between the airborne data processing system and multiple satellite nodes, wherein the real-time communication parameters include the dynamic spectrum occupancy status, polarization direction difference, and covert transmission requirement level of each satellite node;

[0044] an execution module, configured to generate a dynamic frequency hopping control instruction according to the time-varying characteristics of the dynamic spectrum occupancy state, and enable the airborne data processing system to perform spectrum sensing-triggered carrier switching between the licensed frequency band and the unlicensed frequency band through the dynamic frequency hopping control instruction, while retaining a spectrum isolation zone between adjacent carriers;

[0045] 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;

[0046] A generating module, configured to call a preset waveform modulation parameter library to determine a parameter set for weighted fractional Fourier transform based on the concealed transmission requirement level, and load the multi-channel baseband signal onto a subcarrier set having an asymmetric phase characteristic according to the parameter set to generate a concealed modulation waveform;

[0047] The control module is used to input the dynamic frequency hopping control instruction and the spectrum diffusion range of the concealed modulation waveform into the fusion control module of the airborne data processing system and then output a coordinated modulation instruction, and control the airborne radio frequency unit through the coordinated modulation instruction to realize the anti-interference fusion transmission of multi-mode satellite data in a dynamic spectrum sharing environment.

[0048] In a third aspect, an embodiment of the present application provides a computing device comprising 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 communications as described in the first aspect above.

[0049] In a fourth aspect, an embodiment of the present application provides a computer storage medium storing a computer program. When the computer program is executed by a computer, it implements a heterogeneous data fusion transmission method for airborne multi-mode satellite communications as described in the first aspect.

[0050] In an embodiment of the present application, real-time communication parameters between an airborne data processing system and multiple satellite nodes are obtained, wherein the real-time communication parameters include the dynamic spectrum occupancy status, polarization direction difference, and concealed transmission requirement level of each satellite node; dynamic frequency hopping control instructions are generated according to the time-varying characteristics of the dynamic spectrum occupancy status, and the dynamic frequency hopping control instructions are used to enable the airborne data processing system to perform spectrum sensing triggered carrier switching between the authorized frequency band and the unauthorized frequency band, and retain the 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 results to eliminate the spectrum isolation The system detects cross-polarization interference components within the same frequency band, and outputs multi-path baseband signals according to the diversity analysis results; based on the concealed transmission requirement level, calls a preset waveform modulation parameter library to determine a parameter set of weighted fractional Fourier transform, and loads the multi-path baseband signals to a subcarrier set with asymmetric phase characteristics according to the parameter set to generate a concealed modulation waveform; inputs the dynamic frequency hopping control instruction and the spectrum diffusion range of the concealed modulation waveform into the fusion control module of the airborne data processing system, and then outputs a coordinated modulation instruction, and controls the airborne radio frequency unit through the coordinated modulation instruction to realize multi-mode satellite data anti-interference fusion transmission in a dynamic spectrum sharing environment.

[0051] The technical solution of this application has the following beneficial effects:

[0052] Real-time perception of the dynamic spectrum status, polarization differences and concealment requirements of the airborne terminal 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 interference in adjacent frequency bands is reduced by combining the spectrum isolation zone retention mechanism; the polarization direction difference is used to diversity receive signals, suppress cross-polarization interference in the same frequency band, and improve the signal-to-noise ratio and purity of multi-path baseband signals; dynamically adapt the WFRFT parameter set based on concealment requirements, load the baseband signal to the asymmetric phase subcarrier, and realize spectrum diffusion modulation with low interception rate; integrate frequency hopping instructions and concealed waveform spectrum characteristics to generate anti-interference coordination instructions to ensure reliable fusion transmission of multi-mode data in a dynamic spectrum environment.

[0053] Furthermore, the system matches the fractional-order transformation parameter combinations in the preset parameter library according to the required level of covert transmission, decomposing the phase rotation sequence into non-uniformly distributed phase rotation quantities. The subcarrier phase weight coefficients are calculated by combining the order factors. Multiple baseband signals are proportionally distributed to subcarriers, and the signals are rotated and superimposed based on the phase weights to generate subcarrier units. Through time-frequency domain interleaving and phase synchronization, a covert modulation waveform with spectrum diffusion is formed. Through non-uniform phase rotation and nonlinear weight mapping, the subcarrier signals exhibit randomized phase distribution characteristics, destroying the signal's time-frequency domain regularity and reducing the probability of signature recognition by enemy detection equipment. Combined with time-frequency interleaving and phase synchronization, the signal energy distribution range is further expanded, achieving highly covert transmission.

[0054] These and other aspects of the present application will become more readily apparent from the description of the following embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0056] Figure 1 A flowchart of a heterogeneous data fusion transmission method for airborne multi-mode satellite communications provided by the present application is shown;

[0057] Figure 2 A schematic diagram of the structure of a heterogeneous data fusion transmission system for airborne multi-mode satellite communications provided by the present application is shown;

[0058] Figure 3 A schematic structural diagram of a computing device provided by the present application is shown. DETAILED DESCRIPTION

[0059] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0060] In some of the processes described in the specification and claims of this application and the above-mentioned figures, multiple operations that appear in a specific order are included, but it should be clearly understood that these operations may not be executed in the order in which they appear in this document or may be executed in parallel. The serial numbers of the operations, such as 101, 102, etc., are only used to distinguish between different operations, and the serial numbers themselves do not represent any order of execution. 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 of "first", "second", etc. in this document are used to distinguish different messages, devices, modules, etc., and do not represent a sequential order, nor do they limit "first" and "second" to being different types.

[0061] Researchers have found that existing satellite communication systems face three major bottlenecks in airborne multi-mode heterogeneous networking scenarios: low efficiency in dynamic spectrum resource allocation, insufficient interference suppression capabilities within the same frequency band, and poor signal concealment. Based on this, a heterogeneous data fusion transmission method for airborne multi-mode satellite communications is provided. Specifically, by real-time sensing of the spectrum state differences and polarization characteristics of multiple satellite nodes, a frequency band switching mechanism triggered by dynamic spectrum sensing is constructed, and polarization diversity reception and interference cancellation technology are combined to separate multiple signals within the same frequency band. Furthermore, asymmetric phase-modulated subcarrier waveforms are generated based on the dynamic covert transmission requirements, and dynamic adaptation of spectrum diffusion and frequency hopping timing is achieved through collaborative control. This method can improve the spectrum preemption efficiency of multi-mode satellite data in a highly dynamic spectrum environment, suppress cross-band interference, and reduce the interception probability by randomizing the signal time-frequency characteristics, thereby ensuring the reliability of anti-interference covert fusion transmission.

[0062] The technical solution of the present application can be applied to multi-band dynamic preemption and anti-interference transmission scenarios in airborne multi-mode satellite communications.

[0063] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0064] Figure 1 The present invention provides a flowchart of a heterogeneous data fusion transmission method for airborne multi-mode satellite communications. Figure 1 As shown, the method includes:

[0065] 101. Acquire real-time communication parameters between an airborne data processing system and multiple satellite nodes, wherein the real-time communication parameters include a dynamic spectrum occupancy status, polarization direction difference, and covert transmission requirement level of each satellite node;

[0066] In this step, the dynamic spectrum occupancy status refers to the real-time occupancy of authorized and unlicensed frequency bands by each satellite node during communication, including the frequency band identification, occupancy start time, duration, and instantaneous interference intensity level. Polarization direction difference characterizes the phase offset angle, amplitude ratio difference, and polarization angle deviation of the horizontal and vertical polarization components of signals transmitted by different satellite nodes when propagating in space. The covert transmission requirement level is a quantitative indicator of concealment dynamically divided according to the type of communication mission and the complexity of the electromagnetic environment. It includes the spectrum diffusion range, signal phase randomization intensity, and anti-interception priority coefficient.

[0067] In an embodiment of the present application, first, the airborne data processing system performs a frequency domain scan on the frequency band covered by the satellite node through a broadband RF front-end, and uses a sliding window energy detection technology to capture the signal strength changes of each frequency band during the scanning process in real time, and generates a dynamic spectrum occupancy state matrix based on the start time and duration of the frequency band occupancy; secondly, in the carrier synchronization stage, the satellite signal is received by the polarization-sensitive array antenna, and the horizontal and vertical polarization components of the satellite signal are separated by an orthogonal decomposition algorithm. After compensating for the platform attitude angle deviation in the separation process based on the inertial navigation system, the phase offset angle and amplitude ratio difference of the polarization component are calculated, and a polarization direction difference parameter set is output; thirdly, the preset concealment strategy mapping table is called according to the communication task type, and the task identifiers such as reconnaissance and command transmission are converted into discrete concealment levels. The anti-interception priority coefficient in the discrete concealment level is corrected in combination with the number of real-time interference sources to generate a concealed transmission requirement level parameter.

[0068] 102. Generate a dynamic frequency hopping control instruction based on the time-varying characteristics of the dynamic spectrum occupancy state, and use the dynamic frequency hopping control instruction to enable the airborne data processing system to perform spectrum sensing-triggered carrier switching between the licensed frequency band and the unlicensed frequency band, while retaining a spectrum isolation zone between adjacent carriers;

[0069] To solve the problem of communication interruption and cross-band interference caused by untimely frequency band seizure by the airborne platform in a dynamic spectrum environment, in some embodiments, 102 includes:

[0070] 1021. Extract availability parameters of each frequency band from the dynamic spectrum occupancy status, where the availability parameters include a frequency band idle time slot length, an interference intensity threshold, and an adjacent frequency band occupancy duration;

[0071] 1022. Divide the frequency hopping time window according to the idle time slot length of the frequency band, prioritize the candidate frequency band sets of the authorized frequency band and the unlicensed frequency band based on the interference intensity threshold, and generate a dynamic frequency hopping sequence including a frequency hopping timing and a frequency band switching rule;

[0072] 1023. Trigger a spectrum sensing instruction within the frequency hopping time window according to a frequency band switching rule in the dynamic frequency hopping sequence, detect 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;

[0073] 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 carrier switching action based on the spectrum isolation zone rule to complete the spectrum isolation zone configuration.

[0074] In this step, the availability parameter is the core indicator that characterizes the current and future availability of the frequency band. The idle time slot length of the frequency band refers to the length of time that the frequency band is continuously unoccupied. The interference strength threshold refers to the upper limit of the interference signal strength that allows communication. The adjacent frequency band occupation 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 idle time slots of the frequency band. 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 that includes the frequency hopping trigger time, the candidate frequency band priority list, and the dwell time. The spectrum isolation zone rule is a frequency band interval width constraint condition that is dynamically adjusted according to the occupancy status of the adjacent frequency band to avoid adjacent frequency interference.

[0075] In an embodiment of the present application, the airborne system extracts the idle time slot length of each frequency band from the dynamic spectrum occupancy status database, counts the historical occupancy duration of adjacent frequency bands through a sliding time window, and forms an availability parameter set in combination with a preset interference intensity threshold.

[0076] The available frequency band is divided into multiple frequency hopping time windows according to the maximum length of the idle time slot. The window length does not exceed the minimum value of the idle time slot to ensure switching reliability. At the same time, the candidate frequency band set is sorted in two stages based on the interference intensity threshold. The frequency band with the lowest interference intensity in the authorized frequency band is given priority, followed by the frequency band with the longest idle time slot in the unlicensed frequency band. After the two-stage sorting, a dynamic frequency hopping sequence is generated.

[0077] The spectrum sensing module is triggered at the beginning of the frequency hopping time window to detect the instantaneous interference strength of the candidate frequency band set; if the interference strength detected exceeds the threshold, the current frequency band is skipped and switched to the next candidate frequency band according to the preset priority list, forming a carrier switching action.

[0078] The minimum safe interval between the current carrier and the adjacent frequency band is calculated based on the duration of adjacent frequency band occupation. If the adjacent frequency band occupation duration exceeds the preset threshold, the frequency band interval is adjusted to 1.5 times the minimum safe interval. Otherwise, the default interval width is maintained, completing the spectrum isolation zone configuration after carrier switching.

[0079] Here's a specific example:

[0080] Assume that, while an airborne platform is performing multimode satellite communications, the dynamic spectrum occupancy status indicates that the idle slot length of licensed band A is 50 milliseconds, the interference intensity threshold is -90 dBm, the idle slot length of unlicensed band B is 80 milliseconds, the interference intensity threshold is -80 dBm, and the occupation duration of adjacent band C is 30 milliseconds. The preset minimum safety interval is 2 MHz, and the adjacent band occupation duration threshold is 25 milliseconds. Step 1021 extracts the idle time slot of 50 milliseconds, interference threshold of -90 dBm, and 30 milliseconds of occupation of adjacent frequency band C for frequency band A, the idle time slot of 80 milliseconds, and interference threshold of -80 dBm for frequency band B; step 1022 divides the frequency hopping time window into 50 milliseconds, preferentially selects authorized frequency band A, and generates a frequency hopping sequence of "staying in frequency band A for 50 milliseconds and then switching to frequency band B for 80 milliseconds"; step 1023 detects the instantaneous interference strength of frequency band A at the start of the window and finds it is -85 dBm, which is lower than the threshold of -90 dBm, and switches to frequency band A; 50 milliseconds later, detects the interference strength of frequency band B and finds it is -75 dBm, which is higher than the threshold of -80 dBm, skips frequency band B, and switches to the next available frequency band in sequence; step 1024 calculates the occupation duration of adjacent frequency band C, 30 milliseconds, which exceeds the threshold of 25 milliseconds, and expands the default interval of 2 MHz between frequency bands A and C to 1.5 times the minimum safe interval, that is, 3 MHz, to meet the spectrum isolation zone rules.

[0081] Steps 1021-1024 dynamically adjust the frequency band interval through the minimum safety interval threshold judgment mechanism to ensure interference isolation capabilities in scenarios with high occupancy of adjacent frequency bands; combine the preset threshold and the safety interval multiple rule to achieve adaptive configuration of the spectrum isolation zone width to 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 a multi-band dynamic preemption environment.

[0082] Optionally, step 1022 specifically includes the following steps: dividing 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 length of the frequency hopping time window does not exceed the minimum value of the idle time slot length of the frequency band; screening the low-interference candidate frequency bands in the authorized and unauthorized frequency bands based on the interference intensity threshold, and prioritizing the low-interference candidate frequency bands from low to high according to the interference intensity threshold; allocating the residence time of the corresponding frequency band to the sorted low-interference candidate frequency bands, and generating a frequency band residence time list; aligning the frequency hopping time window with the frequency band residence time list according to the time axis, and generating a dynamic frequency hopping sequence including frequency hopping timing, frequency band identification and residence time in combination with the silent period of the frequency hopping time window.

[0083] In an embodiment of the present application, first, the maximum allowable duration of the frequency hopping time window is determined according to the minimum value of the idle time slot length of the frequency band. For example, if the shortest idle time slot in all available frequency bands is 20 milliseconds, then the duration of each window does not exceed 20 milliseconds, ensuring that the frequency band switching does not exceed the idle period after the window division; secondly, based on the interference intensity threshold, the candidate frequency bands with interference intensity lower than the threshold in the authorized frequency band and the unauthorized frequency band are screened respectively. For example, the threshold of the authorized frequency band is set to -90 decibel milliwatts and the threshold of the unauthorized frequency band is set to -80 decibel milliwatts. 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 from low to high according to the interference intensity threshold. For example, a band with an interference intensity of -95 dBm in the authorized band has a higher priority than a band with an interference intensity of -92 dBm, and the same applies to unlicensed bands. Then, the dwell time is allocated in direct proportion to the length of the idle time slots of each band. For example, a band with a longer idle time slot is allocated a longer dwell time, forming a band dwell time list. For example, a band with an idle time slot of 50 milliseconds is allocated a dwell time of 30 milliseconds. Finally, the start time of the frequency hopping time window is aligned with the band dwell time list along the time axis, and a silent period is inserted between adjacent aligned time windows to avoid signal overlap. The frequency hopping timing, frequency band identifier, and dwell time are integrated to generate a dynamic frequency hopping sequence.

[0084] 103. Based on the polarization direction difference, perform orthogonal polarization diversity analysis on the carrier switching result by the airborne data processing system to eliminate cross-polarization interference components within the same frequency band of the spectrum isolation area, and output multiple baseband signals according to the diversity analysis result;

[0085] To solve the problem of cross-polarization interference in the same frequency band caused by polarization direction differences after dynamic spectrum switching of an airborne platform, in some embodiments, 103 includes:

[0086] 1031. Extracting polarization reception parameters of each satellite node based on the polarization direction difference, where the polarization reception parameters include polarization angle deviation, orthogonal polarization signal strength ratio, and cross-polarization interference amplitude;

[0087] 1032. Based on the polarization angle deviation, perform orthogonal polarization decomposition on the carrier switching result 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 time-frequency domain distribution characteristics of each component.

[0088] 1033. Adjust the combined weight of the horizontal polarization component and the vertical polarization component according to the orthogonal polarization signal strength ratio, and simultaneously use the cross-polarization interference amplitude to perform anti-phase superposition and offset on the residual interference component in the same frequency band to generate an orthogonal polarization signal pair;

[0089] 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 a multi-path baseband signal according to the polarization synthesis rule and the adjusted synthesis weight.

[0090] In this step, the polarization reception parameter is a quantitative indicator that characterizes the polarization characteristics of the satellite signal. 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 intensity from other polarization signals in the same frequency band. Orthogonal polarization decomposition is the process of separating the received mixed signal into horizontal and vertical polarization components, preserving the time-frequency domain energy distribution characteristics of each component. Anti-phase superposition cancellation is achieved by generating a cancellation signal with an opposite phase to the interference signal and superimposing it to eliminate the residual interference component. The polarization synthesis rule is a constraint condition that dynamically adjusts the synthesis ratio and phase relationship of the horizontal and vertical polarization components based on the time-frequency domain distribution characteristics.

[0091] In an 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; then, 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, a bandpass filter group is used to extract the peak amplitude of the cross-polarization interference signal in the same frequency band of the satellite signal to obtain the cross-polarization interference amplitude parameter, which ultimately constitutes the polarization reception parameter.

[0092] The phase response of the orthogonal polarization decomposition filter bank is adjusted according to the polarization angle deviation. The received carrier signal is input into the horizontal polarization filter and the vertical polarization filter. The horizontal polarization component and the vertical polarization component are output respectively according to the adjusted phase response. Time-frequency analysis is performed on the two decomposed components, and a sliding time window is used to record the instantaneous frequency distribution and energy concentration area of ​​each component as the time-frequency domain distribution characteristics.

[0093] The combined weight coefficients of the horizontal and vertical components are dynamically calculated based on the orthogonal polarization signal strength ratio. When the horizontal component strength is higher, the weight coefficient is proportionally increased. At the same time, an anti-phase cancellation signal is generated according to the cross-polarization interference amplitude. The anti-phase cancellation signal converts the interference amplitude value into a complex form, takes the conjugate phase, and superimposes it on the corresponding position in the same frequency band of the original signal to eliminate the residual interference component, ultimately generating an orthogonal polarization signal pair containing horizontal and vertical components.

[0094] Combined with the energy concentration area information in the time-frequency domain distribution feature matrix, a polarization synthesis rule is constructed: the maximum weight coefficient is used to merge the corresponding components in the energy concentration area, and the proportional and balanced synthesis is carried out in the energy dispersion area; according to this rule, the horizontal and vertical components are phase aligned and time delay compensated, and then synthesized into multi-channel baseband signals according to the adjusted synthesis weight coefficient.

[0095] Here's a specific example:

[0096] Assume that when an airborne platform simultaneously receives signals from a low-orbit satellite X and a geostationary orbit satellite Y, 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. After compensating for the attitude angle deviation, step 1031 measures a phase difference of 25 degrees between the horizontal and vertical components of satellite X, with an amplitude ratio of 3:1. A peak value of -78 dBm of co-band cross-interference is extracted. Step 1032 applies a quadrature filter with a 25-degree phase offset to satellite X, decomposing the horizontal component, whose main energy is concentrated in the 8-10 MHz range, and the vertical component, whose energy is dispersed in the 6-12 MHz range. The time-frequency energy distribution is recorded. Step 1033 sets a weight of 0.75 for the horizontal component and 0.25 for the vertical component in a 3:1 ratio to generate a -78 dBm cancellation signal with opposite phases, eliminating co-band interference from satellite X. Step 1034 synthesizes the horizontal component in the 8-10 MHz band with a weight of 0.75, and balances the synthesis in the remaining 6-12 MHz range to output the baseband signal of satellite X. The same process is performed for satellite Y to output the baseband signal of satellite Y.

[0097] Steps 1031-1034 accurately separate the horizontal / vertical polarization signal components through dynamic compensation of polarization angle and orthogonal decomposition; optimize the merging efficiency of multi-component signals based on the adaptive synthesis rule of time-frequency energy distribution; and effectively eliminate cross-interference in the same frequency band through anti-phase cancellation technology, significantly improving the signal-to-noise ratio and integrity of the baseband signal, meeting the high-reliability transmission requirements in airborne multi-mode satellite communication scenarios.

[0098] Optionally, step 1033 specifically includes the following steps: calculating a synthesis proportional coefficient of the horizontal polarization component and the vertical polarization component according to the orthogonal polarization signal strength ratio, and generating a weighted polarization component based on the synthesis proportional coefficient; generating an anti-phase cancellation signal with a phase opposite to the residual interference component according to the cross-polarization interference amplitude, and superimposing the anti-phase cancellation signal with the weighted polarization component; performing time-frequency domain energy equalization processing on the superimposed signal, and the energy equalization processing process eliminates the time delay spread component of the residual interference component in the same frequency band to generate an intermediate polarization signal; and generating an orthogonal polarization signal pair after phase alignment of the orthogonal components of the intermediate polarization signal according to a preset time-frequency synchronization rule.

[0099] In the embodiment of the present application, first, the power ratio of the horizontal polarization component to the vertical polarization component is calculated according to the orthogonal polarization signal strength ratio, and the power ratio is converted into a synthesis ratio coefficient. For example, when the horizontal component strength is twice that of the vertical component, the synthesis ratio coefficient is set to 0.67 for the horizontal and 0.33 for the vertical. Secondly, the horizontal and vertical polarization components are weighted and superimposed based on the synthesis ratio coefficient to generate a weighted polarization component. For example, the horizontal component is multiplied by 0.67 and the vertical component is multiplied by 0.33 and then added. Thirdly, 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. The conjugate phase is then taken. For example, an interference amplitude of -80 dBm corresponds to a complex form of 0.1∠180°, which after inversion is 0.1∠0°. This conjugate phase is then added to the weighted polarization component to offset residual interference. The superimposed signal is then subjected to time-frequency domain energy equalization. The delay spread component is suppressed using a time-frequency window function, and the gain is reduced in frequency bands with significant delay spread to generate an intermediate polarization signal. Finally, the horizontal and vertical components of the intermediate polarization signal are phase-aligned according to preset time-frequency synchronization rules. At the start of the time-frequency grid, the phase of the vertical component is adjusted to match that of the horizontal component to generate an orthogonal polarization signal pair.

[0100] 104. Based on the concealed transmission requirement level, call a preset waveform modulation parameter library to determine a parameter set for weighted fractional Fourier transform, and load the multi-channel baseband signal onto a subcarrier set with asymmetric phase characteristics according to the parameter set to generate a concealed modulation waveform;

[0101] In order to solve the problem of easy interception and interference caused by the strong regularity of signal time-frequency characteristics in airborne satellite communications, in some embodiments, 104 includes:

[0102] 1041. According to the discretization level identifier corresponding to the covert transmission requirement level, match a parameter combination of a fractional order transformation from a preset waveform modulation parameter library, where the parameter combination includes a phase rotation sequence and an order factor.

[0103] 1042. Decompose the phase rotation sequence into a plurality of non-uniformly distributed phase rotation amounts, and calculate, based on the order factor, a phase weight coefficient of each subcarrier in the subcarrier set that is nonlinearly mapped to the phase rotation amount;

[0104] 1043. Allocate the multiple baseband signals to the subcarrier set according to a preset ratio, perform phase rotation and superposition on the allocated baseband signals according to a phase weight coefficient of each subcarrier in the subcarrier set, and generate a subcarrier unit according to the superposition result;

[0105] 1044. Interleave the subcarrier units in the time-frequency domain, perform a phase synchronization operation on the arranged subcarrier units according to the timing rule of the phase rotation sequence, and generate a concealed modulation waveform with spectrum diffusion.

[0106] In this step, the phase rotation sequence is a sequence of non-uniformly distributed phase change values ​​used to control the phase offset pattern of the subcarrier signal. The order factor is the core parameter that determines the nonlinear relationship between the phase rotation amount and the subcarrier weight coefficient. The nonlinear mapping relationship is an exponential or polynomial function relationship between the phase weight coefficient and the phase rotation amount established by the order factor. Time-frequency interleaving is to distribute the subcarrier units non-contiguously on the time-frequency resource grid, breaking the signal regularity.

[0107] In an embodiment of the present application, according to the discrete level identifier corresponding to the concealed transmission requirement level, where level 5 represents the highest concealment and level 1 represents the lowest concealment; the parameter combination entry bound to the level is retrieved in the preset waveform modulation parameter library, and the phase rotation sequence and the corresponding order factor defined in the parameter combination entry are extracted.

[0108] The phase rotation sequence is split into multiple phase rotation amounts according to a preset non-uniform interval rule using an arithmetical increase or random interval distribution; a nonlinear mapping function is constructed for each subcarrier based on the order factor, and the phase rotation amount is input into the nonlinear mapping function to calculate the phase weight coefficient. The phase weight coefficient is specifically the power product of the phase rotation amount and the order factor, so that the weight coefficient increases exponentially with the increase of the phase rotation amount.

[0109] The allocation ratio is determined according to the priority of multiple baseband signals, where high-priority signals are allocated to subcarriers with large weight coefficients. A phase rotation and superposition operation is applied to the baseband signal of each subcarrier. The phase rotation and 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.

[0110] Subcarrier units are mapped to discrete time-frequency resource blocks according to the time-frequency interleaving template, which is generated by a pseudo-random sequence. According to the timing rules of the phase rotation sequence, phase synchronization offsets are applied to the subcarrier units of adjacent time-frequency resource blocks to ensure that the initial phase difference of adjacent units is consistent with the timing changes of the phase rotation sequence, ultimately generating a covert modulation waveform with spectrum diffusion.

[0111] Here's a specific example:

[0112] Assuming that when the airborne platform performs a high-covert reconnaissance mission, the covert transmission requirement level is level 5, and the corresponding phase rotation sequence in the parameter library is 45°, 135°, 225°, and the order factor is 3.0. Step 1041 matches level 5 to obtain a phase rotation sequence of 45°, 135°, 225° and an order factor of 3.0. Step 1042 decomposes the sequence into three non-uniform phase rotation amounts of 45°, 135°, and 225°, and calculates the subcarrier weight coefficient according to a nonlinear function, for example, subcarrier 1 weight = 45° × 3.0³ = 1215°. Step 1043 distributes the reconnaissance data baseband signal to three subcarriers in a 2:1:1 ratio, and applies phase rotations of 1215°, 3645°, and 6075°, respectively, to generate subcarrier units. Step 1044 distributes the subcarrier units to positions such as time slot 1-frequency point 3 and time slot 2-frequency point 5 according to a pseudo-random time-frequency template, and synchronizes the phase difference of adjacent units to 90° to generate a concealed modulation waveform.

[0113] Steps 1041-1044 break the regularity of signal phase changes through non-uniform phase rotation decomposition and nonlinear weight mapping; the time-frequency interleaving and phase synchronization mechanism further diffuses the signal energy distribution and reduces the probability of time-frequency feature recognition of enemy detection equipment; the dynamic parameter adaptation driven by the concealment level ensures anti-interception and anti-interference capabilities in different mission scenarios.

[0114] 105. Input the dynamic frequency hopping control instruction and the spectrum diffusion range of the concealed modulation waveform into the fusion control module of the airborne data processing system, and then output a cooperative modulation instruction. The airborne radio frequency unit is controlled by the cooperative modulation instruction to realize the anti-interference fusion transmission of multi-mode satellite data in a dynamic spectrum sharing environment.

[0115] In order to solve the problem of spectrum resource conflict and reduced anti-interference capability caused by insufficient coordination between dynamic frequency hopping and concealed waveform modulation in airborne multi-mode satellite communications, in some embodiments, 105 includes:

[0116] 1051. Analyze the frequency hopping timing parameters and frequency band dwell time in the dynamic frequency hopping control instruction, and extract the frequency coverage interval corresponding to the spectrum diffusion range of the concealed modulation waveform;

[0117] 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 a coordinated modulation parameter for frequency hopping synchronization;

[0118] 1053. Match the frequency band dwell time with the time-frequency resource allocation ratio of the coordinated modulation parameter, and calculate a power allocation coefficient of the carrier radio frequency unit in each frequency band according to the matching degree;

[0119] 1054. Dynamically weight the coordinated modulation parameters into coordinated modulation instructions according to the power allocation coefficient, and control the airborne radio frequency unit to perform anti-interference fusion transmission of multi-mode satellite data through the coordinated modulation instructions.

[0120] In this step, the frequency hopping timing parameters are the frequency hopping trigger time, target frequency band identifier, and dwell time sequence defined in the dynamic frequency hopping control instructions. The frequency coverage interval is the energy diffusion range of the concealed modulation waveform in the frequency domain, including the start frequency, cutoff frequency, and center frequency. The coordinated modulation parameters are modulation control parameters that integrate the frequency hopping timing and the spectral characteristics of the concealed waveform, including the subcarrier phase offset and the time-frequency resource block allocation rules. The power allocation coefficient is the RF transmission power ratio parameter dynamically allocated based on the frequency band dwell time and interference intensity.

[0121] In an embodiment of the present application, the onboard data processing system parses the frequency hopping trigger moment list in the dynamic frequency hopping control instruction, extracts the target frequency band identifier and its residence time corresponding to each trigger moment; synchronously calls the spectrum analysis module to perform fast Fourier transform on the concealed modulation waveform, locates the starting frequency and cutoff frequency of its spectrum energy, and generates frequency coverage interval parameters.

[0122] The center frequency of the target frequency band in the frequency hopping timing parameters is compared with the frequency coverage interval of the concealed waveform. If the target frequency band is completely within the coverage interval, the subcarrier phase distribution parameters remain unchanged. If the target frequency band partially exceeds the coverage interval, the subcarrier phase rotation step is reduced according to the excess ratio. For example, if the part outside the coverage interval accounts for 30%, the phase step is reduced to 70% of the original value, and a phase offset list for frequency hopping synchronization is generated. The phase offset list is bound to the frequency hopping timing parameters to form the coordinated modulation parameters.

[0123] The ratio of the frequency band residence time to the total communication time is used as the basic matching degree of the time-frequency resource allocation ratio. For example, if the residence time of frequency band A accounts for 30% of the total time, the matching degree is 0.3; the number of time-frequency resource blocks is allocated proportionally according to the matching degree, for example, a matching degree of 0.3 corresponds to 30% of the resource blocks; an interference intensity factor is generated 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. The matching degree is multiplied by the interference intensity factor to obtain the power allocation coefficient, for example, a matching degree of 0.3 × an interference factor of 0.8 = a power allocation coefficient of 0.24.

[0124] The power coefficient in the power allocation table and the phase offset in the collaborative modulation parameters are weighted and fused band by band. After weighting, the phase offset is adjusted to the product of the power coefficient and the phase offset. Based on the weighted result, a collaborative modulation instruction containing the frequency band identifier, phase offset and power threshold is generated and sent to the RF unit for execution.

[0125] Here's a specific example:

[0126] Assume that, while performing a multimode satellite communication mission, the airborne platform uses dynamic frequency hopping control instructions to switch from Band A to 2.0 GHz during time slots 0-50 ms, with a dwell time of 50 ms; and from Band B to 2.1 GHz during time slots 60-100 ms, with a dwell time of 40 ms. The total communication duration is 100 ms. The spectrum of the covert modulation waveform is spread over a range of 1.95 GHz to 2.15 GHz. The real-time interference intensity of Band A is detected to be -75 dBm, with a preset maximum interference intensity of -70 dBm. The interference intensity of Band B is -80 dBm. Step 1051 parses the frequency hopping trigger time list and extracts the dwell time of 50 milliseconds for frequency band A and 40 milliseconds for frequency band B; through spectrum analysis, it is determined that the frequency coverage range of the concealed waveform is 1.95GHz-2.15GHz; in step 1052, the center frequency of frequency band A, 2.0GHz, is completely within the range of 1.95-2.15GHz, and the subcarrier phase step is maintained at 15°; the center frequency of frequency band B, 2.1GHz, partially exceeds the upper limit of the coverage range, 2.15GHz (exceeding by 25%), and the phase step is reduced to 15°×75%=11.25°, and a phase offset list is generated. The phase offset list is bound to the frequency hopping timing parameters to form cooperative modulation parameters; step In step 1053, the matching degree of frequency band A is 50 / 100=0.5, and 50% of the time-frequency resource blocks are allocated; the interference factor is (-75+70) / 10=0.5, and the power coefficient is 0.5×0.5=0.25 (adjusted to 0.4 after normalization); the matching degree of frequency band B is 40 / 100=0.4, and 40% of the resource blocks are allocated; the interference factor is (-80+70) / 10=1.0, and the power coefficient is 0.4×1.0=0.4 (adjusted to 0.6 after normalization). In step 1054, the coordinated modulation parameters of frequency band A are 15°×0.4=6°, and those of frequency band B are 11.25°×0.6=6.75°. Instructions are generated to control the RF unit to transmit signals according to these parameters.

[0127] Steps 1051-1054 ensure that the signal energy is precisely concentrated in the target frequency band and avoid spectrum leakage through dynamic matching adjustment of the frequency hopping band and the covert waveform spectrum coverage; based on the quantitative matching mechanism of the dwell time and interference intensity, the power allocation coefficient is objectively calculated, so that the high-interference frequency band obtains higher transmission power; the coordinated optimization of the time-frequency resource allocation ratio and the phase offset significantly improves the spectrum resource utilization efficiency and anti-interference capability, and ensures the continuous and reliable transmission of airborne multi-mode satellite data in a dynamic spectrum environment.

[0128] Assume that the airborne platform needs to communicate simultaneously with the low-orbit satellite Gamma, the medium-orbit satellite Delta, and the geostationary satellite Epsilon. Gamma's polarization deviation is 25 degrees, with a concealment level of 4; Delta's polarization deviation is 15 degrees, with a concealment level of 3; and Epsilon's polarization deviation is 40 degrees, with a concealment level of 5. The dynamic spectrum shows that the licensed frequency band C (2.2 GHz-2.3 GHz) is idle for 60 milliseconds and has an interference threshold of -95 dBm; the unlicensed frequency band D (2.4 GHz-2.5 GHz) is idle for 40 milliseconds and has an interference threshold of -85 dBm; and the adjacent frequency band E (2.35 GHz) is occupied for 50 milliseconds. Step 101 obtains the real-time parameters of Gamma, Delta, and Epsilon: the idle time and interference threshold of frequency bands C / D, the polarization amplitude ratios of 3:1, 1:1, and 4:1, respectively, and concealment levels of 4, 3, and 5. Step 102 divides the frequency hopping window into 40-ms intervals based on the idle time of 60 ms for frequency band C, with a 5-ms silent interval. After priority sorting, the sequence "C dwell 40 ms → D dwell 30 ms" is generated. Since frequency band E exceeds the threshold occupancy, the interval between C and E is extended to 3 MHz. Step 103 decomposes the gamma signal into a 75% horizontal component and a 25% vertical component, generating an antiphase signal to eliminate -80 dBm interference. Delta is weighted at 1:1, and Epsilon at 4:1, to output three baseband signals. In step 104, Epsilon uses a phase sequence of 45° / 135° / 225° and an order factor of 3.0 to calculate subcarrier weights of 1215° / 3645° / 6075°. The baseband signals are allocated and loaded at a 2:1:1 ratio, generating a 2.1-2.6 GHz diffuse waveform. In step 105, the phase step of frequency band C is 15°, and the phase step of part D is reduced to 12° due to the over-range; the power coefficients C 0.6 and D 0.4 are allocated according to the dwell time, and the RF transmission is controlled through coordinated instructions.

[0129] Steps 101-105 achieve real-time and efficient utilization of multi-band resources through dynamic spectrum preemption and adaptive frequency hopping mechanisms; orthogonal polarization diversity analysis and anti-phase cancellation technology effectively suppress cross-interference in the same frequency band and improve signal quality; asymmetric phase modulation and time-frequency interleaving significantly enhance signal concealment and reduce the probability of interception; the collaborative control module integrates frequency hopping and concealment parameters to ensure anti-interference and reliable transmission of multi-mode satellite data in complex electromagnetic environments, meeting the requirements of high real-time performance and high concealment.

[0130] Figure 2 The present invention provides a schematic diagram of a heterogeneous data fusion transmission system for airborne multi-mode satellite communications. Figure 2 As shown, the system includes:

[0131] An acquisition module 21 is configured to acquire real-time communication parameters between the airborne data processing system and multiple satellite nodes, wherein the real-time communication parameters include the dynamic spectrum occupancy status, polarization direction difference, and covert transmission requirement level of each satellite node;

[0132] an execution module 22, configured to generate a dynamic frequency hopping control instruction based on the time-varying characteristics of the dynamic spectrum occupancy state, and enable the airborne data processing system to perform spectrum sensing-triggered carrier switching between the licensed frequency band and the unlicensed frequency band through the dynamic frequency hopping control instruction, while retaining a spectrum isolation zone between adjacent carriers;

[0133] An output module 23 is 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 cross-polarization interference components within the same frequency band of the spectrum isolation area, and output multiple baseband signals according to the diversity analysis result;

[0134] A generating module 24 is configured to call a preset waveform modulation parameter library to determine a parameter set for weighted fractional Fourier transform based on the concealed transmission requirement level, and load the multi-channel baseband signal onto a subcarrier set having an asymmetric phase characteristic according to the parameter set to generate a concealed modulation waveform;

[0135] The control module 25 is used to input the dynamic frequency hopping control instruction and the spectrum diffusion 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 through the cooperative modulation instruction to realize multi-mode satellite data anti-interference fusion transmission in a dynamic spectrum sharing environment.

[0136] Figure 2 The heterogeneous data fusion transmission system for airborne multi-mode satellite communications can be implemented Figure 1 The implementation principles and technical effects of the heterogeneous data fusion transmission method for airborne multi-mode satellite communications described in the illustrated embodiment are not further elaborated. The specific manner in which the various modules and units perform operations in the heterogeneous data fusion transmission system for airborne multi-mode satellite communications in the aforementioned embodiment have been described in detail in the related embodiments and will not be further elaborated here.

[0137] In one possible design, Figure 2 The heterogeneous data fusion transmission system for airborne multi-mode satellite communication of the embodiment shown can be implemented as a computing device, such as Figure 3 As shown, the computing device may include a storage component 31 and a processing component 32;

[0138] The storage component 31 stores one or more computer instructions, wherein the one or more computer instructions are called and executed by the processing component 32 .

[0139] The processing component 32 is used for the above Figure 1 The embodiment provides a heterogeneous data fusion transmission method for airborne multi-mode satellite communications.

[0140] 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 method. Of course, the processing component may also be implemented as 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 to perform the above method.

[0141] The storage component 31 is configured to store various types of data to support operations at the terminal. The storage component can be implemented by any type of volatile or non-volatile memory 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.

[0142] Of course, a computing device may also include other components, such as input / output interfaces, display components, communication components, etc.

[0143] The input / output interface provides an interface between the processing component and the peripheral interface module, which can be an output device, an input device, etc.

[0144] The communication component is configured to facilitate, among other things, wired or wireless communications between the computing device and other devices.

[0145] Among them, the computing device can be a physical device or an elastic computing host provided by a cloud computing platform, etc. In this case, the computing device can refer to a cloud server, and the above-mentioned processing components, storage components, etc. can be basic server resources rented or purchased from the cloud computing platform.

[0146] The present application also provides a computer storage medium storing a computer program, wherein the computer program can achieve the above-mentioned Figure 1 The illustrated embodiment provides a heterogeneous data fusion transmission method for airborne multi-mode satellite communications.

[0147] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0148] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0149] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion 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, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods described in each embodiment or certain portions of the embodiments.

[0150] 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 aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A heterogeneous data fusion transmission method for airborne multi-mode satellite communications, characterized in that: include: Acquiring real-time communication parameters between an airborne data processing system and multiple satellite nodes, wherein the real-time communication parameters include a dynamic spectrum occupancy status, polarization direction difference, and covert transmission requirement level of each satellite node; generating a dynamic frequency hopping control instruction based on the time-varying characteristics of the dynamic spectrum occupancy state, and causing the onboard data processing system to perform spectrum sensing-triggered carrier switching between the licensed frequency band and the unlicensed frequency band through the dynamic frequency hopping control instruction, while retaining a spectrum isolation zone 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 cross-polarization interference components within the same frequency band of the spectrum isolation area, and outputs multiple baseband signals according to the diversity analysis result; Based on the concealed transmission requirement level, calling a preset waveform modulation parameter library to determine a parameter set for weighted fractional Fourier transform, and loading the multi-channel baseband signal onto a subcarrier set with asymmetric phase characteristics according to the parameter set to generate a concealed modulation waveform; The dynamic frequency hopping control instruction and the spectrum diffusion range of the concealed modulation waveform are input into the fusion control module of the airborne data processing system, and then a cooperative modulation instruction is output. The airborne radio frequency unit is controlled by the cooperative modulation instruction to realize anti-interference fusion transmission of multi-mode satellite data in a dynamic spectrum sharing environment.

2. The method according to claim 1, characterized in that The method includes calling a preset waveform modulation parameter library to determine a parameter set of weighted fractional Fourier transform based on the concealed transmission requirement level, and loading the multi-channel baseband signal onto a subcarrier set with an asymmetric phase characteristic according to the parameter set to generate a concealed modulation waveform, including: According to the discretization level identifier corresponding to the covert transmission requirement level, matching a parameter combination of a fractional order transformation from a preset waveform modulation parameter library, the parameter combination including a phase rotation sequence and an order factor; Decomposing the phase rotation sequence into a plurality of non-uniformly distributed phase rotation amounts, and calculating a phase weight coefficient of each subcarrier in the subcarrier set that is nonlinearly mapped to 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 and 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; 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 concealed modulation waveform with spectrum diffusion.

3. The method according to claim 1, characterized in that Generating a dynamic frequency hopping control instruction according to the time-varying characteristics of the dynamic spectrum occupancy state, causing the airborne data processing system to perform spectrum sensing-triggered carrier switching between a licensed frequency band and an unlicensed frequency band through the dynamic frequency hopping control instruction, and retaining a spectrum isolation zone between adjacent carriers, includes: Extracting availability parameters of each frequency band from the dynamic spectrum occupancy status, the availability parameters including frequency band idle time slot length, interference intensity threshold, and adjacent frequency band occupancy duration; 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, and generating a dynamic frequency hopping sequence including the frequency hopping timing and the frequency band switching rule; triggering a spectrum sensing instruction according to a frequency band switching rule in the dynamic frequency hopping sequence within the frequency hopping time window, detecting instantaneous interference intensity of the candidate frequency band set through the spectrum sensing instruction, and generating 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 adjacent frequency band occupancy duration, so that the width of the frequency band interval meets the preset spectrum isolation zone rules, and perform carrier switching action based on the spectrum isolation zone rules to complete the spectrum isolation zone configuration.

4. The method according to claim 1, wherein The method further comprises: performing orthogonal polarization diversity analysis on the carrier switching result by the onboard data processing system based on the polarization direction difference 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, including: Extracting polarization reception parameters of each satellite node according to the polarization direction difference, wherein the polarization reception parameters include polarization angle deviation, orthogonal polarization signal strength ratio, and cross-polarization interference amplitude; Based on the polarization angle deviation, the airborne data processing system performs orthogonal polarization decomposition on the carrier switching result, wherein 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; Adjusting the synthesis weight of the horizontal polarization component and the vertical polarization component according to the orthogonal polarization signal strength ratio, and using the cross-polarization interference amplitude to perform anti-phase superposition and offset on the residual interference components in the same frequency band to generate an orthogonal polarization signal pair; A polarization synthesis rule is established based on the orthogonal polarization signal pair and the time-frequency domain distribution characteristics, and the horizontal polarization component and the vertical polarization component are synthesized into a multi-path baseband signal according to the polarization synthesis rule and the adjusted synthesis weight.

5. The method according to claim 3, characterized in that The method further comprises dividing the frequency hopping time window according to the idle time slot length 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 a frequency hopping timing and a frequency band switching rule, including: Dividing the continuous available frequency band into frequency hopping time windows according to the idle time slot length of the frequency band, wherein the window length of the frequency hopping time window does not exceed the minimum value of the idle time slot length of the frequency band; Screening low-interference candidate frequency bands in authorized and unauthorized frequency bands based on the interference intensity threshold, and prioritizing the low-interference candidate frequency bands from low to high according to the interference intensity threshold; Allocate dwell times of corresponding frequency bands to the sorted low-interference candidate frequency bands, and generate a frequency band dwell time list; The frequency hopping time window is aligned with the frequency band dwell time list according to a time axis, and a dynamic frequency hopping sequence including a frequency hopping timing, a frequency band identifier and a dwell time is generated in combination with a silent period of the frequency hopping time window.

6. The method according to claim 4, characterized in that The adjusting the synthesis weight of the horizontal polarization component and the vertical polarization component according to the orthogonal polarization signal strength ratio, and simultaneously using the cross-polarization interference amplitude to perform anti-phase superposition and offset on the residual interference component in the same frequency band to generate an orthogonal polarization signal pair, includes: Calculating a synthesis proportional coefficient of the horizontal polarization component and the vertical polarization component according to the orthogonal polarization signal strength ratio, and generating a weighted polarization component based on the synthesis proportional coefficient; generating an anti-phase cancellation signal having a phase opposite to that of the residual interference component according to the cross-polarization interference amplitude, and superimposing the anti-phase cancellation signal with the weighted polarization component; The superimposed signals are subjected to time-frequency domain energy equalization processing. The energy equalization process eliminates the delay spread component of the residual interference component in the same frequency band and generates an intermediate polarization signal. The orthogonal components of the intermediate polarization signal are phase-aligned according to a preset time-frequency synchronization rule to generate an orthogonal polarization signal pair.

7. The method according to claim 1, characterized in that The method includes inputting the dynamic frequency hopping control instruction and the spectrum diffusion range of the concealed modulation waveform into the fusion control module of the airborne data processing system, outputting a coordinated modulation instruction, and controlling the airborne radio frequency unit to achieve anti-interference fusion transmission of multi-mode satellite data in a dynamic spectrum sharing environment through the coordinated modulation instruction, including: parsing the frequency hopping timing parameters and the frequency band dwell time in the dynamic frequency hopping control instruction, and extracting the frequency coverage interval corresponding to the spectrum diffusion range of the concealed modulation waveform; Adjusting 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 the coordinated modulation parameters for frequency hopping synchronization; Matching the frequency band dwell time with the time-frequency resource allocation ratio of the coordinated modulation parameter, and calculating the power allocation coefficient of the carrier radio frequency unit in each frequency band according to the matching degree; The coordinated modulation parameters are dynamically weighted into coordinated modulation instructions according to the power allocation coefficient, and the airborne radio frequency unit is controlled by the coordinated modulation instructions to perform anti-interference fusion transmission of multi-mode satellite data.

8. A heterogeneous data fusion transmission system for airborne multi-mode satellite communications, characterized in that: include: an acquisition module, configured to acquire real-time communication parameters between the airborne data processing system and multiple satellite nodes, wherein 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 state, and enable the airborne data processing system to perform spectrum sensing-triggered carrier switching between the licensed frequency band and the unlicensed frequency band through the dynamic frequency hopping control instruction, while retaining a spectrum isolation zone 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 generating module, configured to call a preset waveform modulation parameter library to determine a parameter set for weighted fractional Fourier transform based on the concealed transmission requirement level, and load the multi-channel baseband signal onto a subcarrier set having an asymmetric phase characteristic according to the parameter set to generate a concealed modulation waveform; The control module is used to input the dynamic frequency hopping control instruction and the spectrum diffusion range of the concealed modulation waveform into the fusion control module of the airborne data processing system and then output a coordinated modulation instruction, and control the airborne radio frequency unit through the coordinated modulation instruction to realize the anti-interference fusion transmission of multi-mode satellite data in a dynamic spectrum sharing environment.

9. A computing device, characterized in that The invention comprises 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 communications as described in any one of claims 1 to 7.

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

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