Unmanned aerial vehicle satellite navigation interference signal generation method and system based on FPGA

Abstract

The invention relates to an FPGA-based unmanned aerial vehicle satellite navigation interference signal generation method and system, and belongs to the technical field of electronic communication, and the method comprises the steps: generating a reference clock signal according to a pseudo code rate demand of a target navigation system; performing frequency division processing according to the reference clock signal to obtain a plurality of frequency division clock signals; receiving a satellite identifier list of an area where the target unmanned aerial vehicle is located, dividing time slices based on the frequency division clock signal, and circularly generating a pseudo code sequence matched with the satellite identifier list; acquiring satellite navigation message data and dynamically binding the satellite navigation message data with the pseudo code sequence according to the satellite identifier; generating a multi-frequency-point navigation signal from the bound satellite navigation message data and pseudo code sequence according to a modulation rule; performing frequency offset adjustment based on each frequency point in the multi-frequency-point navigation signal, and performing superposition to generate a full-band interference signal; and transmitting the full-band interference signal to an area where the target unmanned aerial vehicle is located. According to the invention, the interference effect on multi-frequency-point and multi-system unmanned aerial vehicle satellite navigation signals can be enhanced.

Description

Technical Field

[0001] The present application relates to the field of electronic communication technologies, and in particular, to a method and system for generating interference signals for UAV satellite navigation based on FPGA. Background Art

[0002] Satellite navigation systems have become an indispensable technical support in modern society and are widely used in fields such as UAVs, vehicle navigation, military operations, surveying and positioning, etc. Especially in the navigation and positioning of UAVs, satellite navigation systems provide crucial data support. The positioning of UAVs usually relies on satellite navigation systems such as the Global Positioning System (GPS), BeiDou Satellite Navigation System (BDS), GLONASS, QZSS, and Galileo. The precise positioning functions provided by these systems are crucial for UAVs to perform tasks. However, in some special occasions, such as military countermeasures, UAV no-fly zone control, etc., it may be necessary to interfere with the satellite navigation signals of UAVs to prevent UAVs from entering sensitive areas or performing sensitive tasks.

[0003] Currently, traditional interference technologies, such as spoofing interference and signal deception interference, usually rely on complex hardware configurations and consume a large amount of resources. This makes these systems less portable and less efficient in dealing with the interference of multiple frequency points and multi-system satellite navigation signals, resulting in a large amount of hardware overhead and high resource occupancy. For example, although existing co-frequency multi-system navigation signal generation systems can generate four different navigation signals, their frequency point coverage is limited, unable to effectively cover the frequencies of all satellite navigation signals, and it is difficult to handle the situation where multiple UAVs receive interference signals simultaneously. Summary of the Invention

[0004] In order to enhance the interference effect on multi-frequency point and multi-system UAV satellite navigation signals, the present application provides a method and system for generating interference signals for UAV satellite navigation based on FPGA.

[0005] In a first aspect, the present application provides a method for generating interference signals for UAV satellite navigation based on FPGA, adopting the following technical solutions: A method for generating interference signals for UAV satellite navigation based on FPGA, the method comprising: Generating a reference clock signal according to the pseudo-code rate requirement of the target navigation system; Performing frequency division processing on the reference clock signal to obtain a plurality of divided clock signals; Receiving a list of satellite identifiers in the area where the target UAV is located, dividing time slices based on the divided clock signals, and cyclically generating a pseudo-code sequence matching the list of satellite identifiers; Obtaining satellite navigation message data and dynamically binding it with the pseudo-code sequence according to the satellite identifier; Generate multi-frequency navigation signals according to the modulation rules for the satellite navigation message data and the pseudo-code sequence after binding; Perform frequency offset adjustment based on each frequency point in the multi-frequency navigation signals, and superimpose to generate a full-band interference signal; Transmit the full-band interference signal to the area where the target UAV is located; the full-band interference signal is used to cover the working frequency band of the satellite navigation receiver of the target UAV.

[0006] By adopting the above technical solution, multi-frequency navigation signals are generated based on FPGA, and the time-division multiplexing and coherent interference technologies are used to comprehensively interfere with the satellite navigation system of the target UAV. Through steps such as precise clock generation, frequency division, pseudo-code generation, dynamic binding, modulation, frequency offset adjustment and signal superposition, not only can interference signals matching multiple satellite systems be generated efficiently, but also a wide frequency band can be covered to provide a strong interference effect. At the same time, the system is efficient in the use of hardware resources. Through the parallel processing ability of FPGA and the time-division multiplexing technology, the resource occupancy is reduced, enabling the system to be implemented on a smaller hardware platform.

[0007] Optionally, the steps of receiving the satellite identification list of the area where the target UAV is located, dividing time slices based on the frequency-divided clock signal, and cyclically generating a pseudo-code sequence matching the satellite identification list include: According to the satellite identification list of the area where the target UAV is located, based on the frequency-divided clock signal, divide the total time into multiple time slices equal to the number of satellite identifications in the satellite identification list; Cyclically generate the corresponding pseudo-code sequence according to the satellite identification list within each time slice until the pseudo-code sequences of all satellite identifications are generated.

[0008] By adopting the above technical solution, the system can efficiently divide time slices based on the frequency-divided clock signal according to the satellite identification list of the target area, and cyclically generate a pseudo-code sequence matching the satellite identification within each time slice. This technical solution effectively avoids the conflict and resource waste of multi-satellite signals, and ensures the synchronization and accuracy of the system when processing multi-satellite signals through the time-division multiplexing technology. At the same time, by cyclically generating the pseudo-code sequence, it is ensured that the pseudo-code generation of each satellite is completed within an independent time window, thus avoiding overloading of the system and computational bottlenecks. This solution has high efficiency and scalability, and can realize the generation and management of complex signals under limited hardware resources.

[0009] Optionally, the pseudo-code sequence includes cyclic shift code, stepped code, CDMA spreading code and military pseudo-code.

[0010] Optionally, the generation of the pseudo-code sequence includes: Generate cyclic shift codes through a cyclic shift register; the generating polynomial of the cyclic shift codes is based on the Gold code structure of the target navigation system; Generate step codes through the exclusive OR operation of the main code and the secondary code; the code lengths of the main code and the secondary code match the target navigation system; Generate CDMA spreading codes based on the spreading modulation rules; the spreading modulation rules include the dynamic switching between high-frequency modulation codes and low-frequency modulation codes; Generate military pseudo-codes according to the truncation period and exclusive OR logic of military navigation signals.

[0011] By adopting the above technical solutions, according to the requirements of the target navigation system, using the technologies of cyclic shift register, step code generation, CDMA spreading, and military pseudo-code generation, generate pseudo-code sequences that meet the requirements of navigation signals. These pseudo-code sequences ensure the spreading effect and anti-interference ability of navigation signals while also improving the encryption and security of the signals.

[0012] Optionally, the step of generating a full-band interference signal by performing frequency offset adjustment on each frequency point of the multi-frequency navigation signal and superimposing them includes: Perform complex multiplication operations on the navigation signals of each frequency point to generate frequency offset signals; Superimpose the frequency offset signals through an adder tree to generate a full-band interference signal covering the satellite navigation of the target UAV.

[0013] By adopting the above technical solutions, the system can first perform frequency offset adjustment on the navigation signals of each frequency point through complex multiplication, and then efficiently superimpose multiple frequency offset signals through an adder tree to generate a full-band interference signal covering the satellite navigation of the target UAV. This process enables the system to flexibly adjust the frequency offset amount of each frequency point and effectively synthesize an interference signal over a wide frequency band, enhancing the range and effect of the interference signal. Through the adder tree structure, the system reduces the hardware complexity while maintaining high efficiency, ensuring the effective coverage and transmission of the interference signal in the target frequency band.

[0014] In a second aspect, the present application provides a UAV satellite navigation interference signal generation system based on FPGA, adopting the following technical solutions: A UAV satellite navigation interference signal generation system based on FPGA, the system includes: A clock generation module, configured to generate a reference clock signal according to the pseudo-code rate requirement of the target navigation system and perform frequency division processing to obtain a plurality of divided clock signals; A pseudo-code sequence generation module, configured to receive a list of satellite identifiers in the area where the target UAV is located, divide time slices based on the divided clock signals, and cyclically generate a pseudo-code sequence that matches the list of satellite identifiers; A modulation module, configured to obtain satellite navigation message data and perform dynamic binding with the pseudo-code sequence according to the satellite identifier, and generate multi-frequency navigation signals according to the modulation rules; A mixing and superposition module, configured to perform frequency offset adjustment based on each frequency point in the multi-frequency navigation signals, and superpose and generate a full-band interference signal; A radio frequency transmitting module, configured to transmit the full-band interference signal to the area where the target UAV is located; the full-band interference signal is used to cover the working frequency band of the satellite navigation receiver of the target UAV.

[0015] Optionally, the pseudo-code sequence generation module includes a plurality of parallel pseudo-code generation units, and each pseudo-code generation unit generates pseudo-code sequences with different satellite identifiers according to time division multiplexing logic; The pseudo-code generation unit includes: A cyclic shift code generator, configured to output a cyclic shift code based on the generating polynomial of the Gold code structure; A stepped code generator, configured to generate a stepped code through the exclusive OR operation of a main code and a sub-code; the code lengths of the main code and the sub-code match the target navigation system; A CDMA spreading code generator, configured to dynamically switch and generate a CDMA spreading code according to high-frequency / low-frequency modulation rules; A military pseudo-code generator, configured to generate a military pseudo-code based on a truncated period and exclusive OR logic.

[0016] Optionally, the mixing and superposition module includes: A complex multiplier, configured to perform complex multiplication operations on the navigation signals of each frequency point to generate frequency offset signals; An adder tree structure, configured to superpose the frequency offset signals through an adder tree to generate a full-band interference signal covering the satellite navigation of the target UAV.

[0017] In a third aspect, the present application provides a computer device, adopting the following technical solution: A computer device includes a memory, a processor, and a computer program stored on the memory, and the processor executes the computer program to implement the steps of the method as described in the first aspect.

[0018] In a fourth aspect, the present application provides a computer-readable storage medium, adopting the following technical solution: A computer-readable storage medium stores a computer program that can be loaded and executed by a processor to implement any one of the methods in the first aspect.

[0019] In summary, the present application includes at least one of the following beneficial technical effects: By precisely generating a pseudo-code sequence that matches the target navigation system and dynamically binding satellite navigation message data, it is possible to effectively generate multi-frequency navigation signals and perform frequency offset adjustment, and finally superimpose them into a full-band interference signal to cover the working frequency band of the target UAV satellite navigation receiver. It has strong anti-jamming ability, can effectively suppress the satellite navigation signal of the UAV, improve the interference effect. At the same time, the high efficiency and flexibility of this solution make it have important practical application significance in the fields of UAV anti-jamming and electronic warfare, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 FIG. is a first flowchart of a method for generating a UAV satellite navigation interference signal according to one embodiment of the present application.

[0021] Figure 2 FIG. is a flowchart of BPSK modulation according to one embodiment of the present application.

[0022] Figure 3 FIG. is a flowchart of BOC modulation according to one embodiment of the present application.

[0023] Figure 4 FIG. is a second flowchart of a method for generating a UAV satellite navigation interference signal according to one embodiment of the present application.

[0024] Figure 5 FIG. is a flowchart of time division multiplexing according to one embodiment of the present application.

[0025] Figure 6 FIG. is a flowchart of generating a ladder code according to one embodiment of the present application.

[0026] Figure 7 FIG. is a flowchart of generating a CDMA spreading code according to one embodiment of the present application.

[0027] Figure 8 FIG. is a third flowchart of a method for generating a UAV satellite navigation interference signal according to one embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] In order to make the objectives, technical solutions and advantages of the present application clearer, the following further describes the present application in detail with reference to the accompanying Figure 1-8 drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0029] At present, most common satellite navigation jamming systems use static configuration, such as instantiating multiple channels to jam different satellite IDs respectively, which results in multiple channels being instantiated to jam multiple satellite IDs, increasing the complexity and resource consumption of the system. In addition, these systems have obvious limitations when dealing with multiple frequency interference, making it difficult to efficiently and accurately jam multiple frequency bands of different navigation systems at the same time, and there are bottlenecks in the efficient use of hardware resources.

[0030] Therefore, how to perform efficient interference in a multi-frequency, multi-system environment while reducing the occupation of hardware resources is a technical problem that needs to be solved urgently.

[0031] Based on this, an embodiment of the present application discloses a method for generating satellite navigation interference signals for unmanned aerial vehicles based on FPGA.

[0032] Reference Figure 1 , a method for generating satellite navigation interference signals for unmanned aerial vehicles based on FPGA, the method comprising: Step S101, generating a reference clock signal according to the pseudo code rate requirement of the target navigation system; The frequency of the reference clock signal is determined according to the lowest common multiple of the pseudo code rate requirements. The pseudo code rate is the rate of the pseudo code generation cycle in the signals of different navigation systems, which is usually specified by the standard protocol of the satellite navigation signal. For example, the pseudo code rate of the GPS L1 band is 1.023MHz, while the pseudo code rates of other systems such as GLONASS and BDS are different. In order to ensure the synchronization and generation accuracy of the signal, a reference clock signal needs to be generated, and its frequency should be compatible with the pseudo code rate requirements of all target navigation systems.

[0033] Specifically, the frequency of the reference clock signal is determined according to the least common multiple of the pseudo code rate requirements of multiple systems, so that the reference clock can not only meet the pseudo code rate requirements of all systems, but also ensure that the signals of each system will not interfere or misalign. For example, if the pseudo code rate of one system is 1.023MHz and the other is 1.5MHz, the reference clock should be the least common multiple of the two, that is, 15.36MHz.

[0034] It can be understood that, by generating the reference clock, it is ensured that all pseudo code generation modules can work synchronously, the error in time synchronization is reduced, and the overall stability and reliability of the system are improved.

[0035] Step S102, performing frequency division processing according to the reference clock signal to obtain a plurality of frequency-divided clock signals; Among them, in practical applications, different satellite navigation systems may require different pseudo-code rates. To meet these different requirements, the reference clock signal needs to be frequency-divided to generate multiple clock signals with different frequencies, and these clock signals respectively correspond to the pseudo-code rates of each satellite system. For example, the GPS signal requires 1.023 MHz, while other systems may require different frequencies. Through frequency division processing, it is ensured that the system can provide an accurate clock source for each satellite signal, thereby improving the accuracy and reliability of pseudo-code generation, and at the same time reducing the consumption of hardware resources.

[0036] Specifically, through a frequency division circuit (such as a programmable frequency divider or a digital clock manager), the reference clock is frequency-divided into clocks that adapt to the requirements of different satellite signals. For example, if the reference clock is 15.36 MHz, then through a suitable frequency divider, clocks with multiple frequencies such as 1.023 MHz and 1.5 MHz can be obtained.

[0037] Step S103, receive the satellite identification list of the area where the target UAV is located, divide time slices based on the frequency-divided clock signal, and cyclically generate a pseudo-code sequence that matches the satellite identification list; Among them, each frequency-divided clock signal corresponds to the pseudo-code generation requirements of a specific navigation system, each time slice corresponds to a satellite identification (ID), and the pseudo-code sequence includes a cyclic shift code, a stepped code, a CDMA spreading code, and a military pseudo-code.

[0038] In some embodiments, the UAV usually navigates within a specific area and receives the satellite navigation signals in its area. The system needs to obtain the satellite identification list within the area where the target UAV is located and generate corresponding pseudo-code sequences according to these satellite identifications. To efficiently generate these pseudo-code sequences, time division multiplexing (TDM) technology can be used to divide time into multiple time slices, each time slice corresponds to a satellite ID, and the pseudo-code sequences of different satellites are generated one by one in a cyclic manner.

[0039] Specifically, for each satellite ID, the system generates a pseudo-code sequence that matches the satellite ID within a time slice. Assuming there are 32 satellites in the target area, the system can divide time into 32 time slices and generate the pseudo-codes of the corresponding satellites within each time slice. The division of time slices can be dynamically adjusted according to the number of satellites to ensure that the pseudo-codes of each satellite can be generated and transmitted within a reasonable time.

[0040] It can be understood that the time division multiplexing technology reduces the number of parallel channels in the system, thereby reducing the consumption of hardware resources, while ensuring the synchronous generation of multi-satellite navigation signals and improving the processing efficiency of the system.

[0041] Step S104, obtain the satellite navigation message data and perform dynamic binding according to the satellite identification and the pseudo-code sequence; Among them, the message data in the satellite navigation signal contains information such as the satellite's clock and orbit, which determines the signal content transmitted by each satellite. During the process of generating the pseudo-code, it is necessary to bind the satellite message data with the corresponding pseudo-code sequence to ensure that the signal transmitted by each satellite matches its message data. Through dynamic binding, it can be ensured that there is no confusion between different satellite signals, and the pseudo-code sequence and message content of each satellite signal remain consistent.

[0042] Specifically, the system dynamically extracts the navigation message corresponding to the satellite ID from the pre-stored message data according to the received satellite ID, and then binds it with the generated pseudo-code sequence to form a complete navigation signal message, thus ensuring the correctness and accuracy of the navigation signal, avoiding the problem of data mismatch between different satellites, and thus improving the quality of the interference signal.

[0043] Step S105, generating a multi-frequency navigation signal according to the modulation rule from the bound satellite navigation message data and pseudo-code sequence; Among them, the navigation signal needs to go through a modulation process in order to be transmitted in a suitable frequency band. Each satellite navigation system uses different modulation methods (such as BPSK, QPSK, BOC, etc.), and the signals of each frequency point need to meet the frequency requirements of that frequency band. According to the frequency point requirements of the target navigation system, the system generates a multi-frequency navigation signal according to the specified modulation rule from multiple satellite signals. The multi-frequency can cover the working frequency band of the UAV navigation system, effectively expanding the coverage range of the interference signal and ensuring that the system can interfere with multiple navigation signal frequency bands simultaneously.

[0044] Specifically, during the modulation process, the system combines the message data of different satellites with the pseudo-code sequence, and applies modulation techniques such as BPSK or BOC(1,1) to modulate the signals of different frequency points. Finally, these signals will be transmitted on different frequency bands to ensure that they cover the navigation receiving frequency band of the UAV.

[0045] Refer to Figure 2 , in one embodiment of the present application, for example, the BPSK modulation method is adopted and implemented through the exclusive OR operation in the figure, avoiding the traditional multiplication calculation. First, the receiver reads the navigation message data from the RAM and performs an exclusive OR process bit by bit with the pseudo-code to generate the modulated signal bits. This process assigns values by judging whether the exclusive OR result is 0 or 1, and finally generates the corresponding BPSK modulation signal. In this way, the traditional multiplication is replaced by a simple logical operation, significantly saving DSP resources while ensuring the modulation accuracy.

[0046] Refer to Figure 3, in another embodiment of the present application, for example, using the BOC modulation method, a square wave signal of different frequencies is generated by DDS and modulated according to the modulation formula. First, the DDS module generates a square wave signal of the required frequency, then performs an exclusive OR operation with the pseudo-code and the message signal bit by bit, avoiding multiplication operations, and then generates a BOC modulation signal through addition and subtraction operations. This design greatly reduces the consumption of hardware resources while maintaining the accuracy and correctness of signal modulation.

[0047] Step S106: Based on each frequency point in the multi-frequency navigation signal, perform frequency offset adjustment and superimpose to generate a full-band interference signal; Among them, in order to more efficiently interfere with the navigation signal of the UAV, it is necessary to perform frequency offset adjustment on the generated navigation signal. This can be achieved by changing the phase or frequency of the frequency point signal to simulate the influence of the interference signal on the satellite receiver. By superimposing the interference signals of different frequency points, the system can cover and interfere with the navigation signal of the UAV within the full band.

[0048] Specifically, perform frequency offset adjustment on each generated frequency point signal, and then superimpose all the signals through the mixing process to generate a full-band interference signal. The frequency offset adjustment and signal superposition can cover the entire navigation band, comprehensively interfere with the satellite navigation signal of the target UAV, and improve the range and intensity of the interference effect.

[0049] Step S107: Transmit the full-band interference signal to the area where the target UAV is located; the full-band interference signal is used to cover the working band of the satellite navigation receiver of the target UAV.

[0050] Among them, the generated full-band interference signal needs to be transmitted to the target area through an appropriate transmitting device to affect the reception of the navigation signal of the UAV. This step ensures that the interference signal can cover all the frequency bands used by the UAV, ensuring that the UAV in the target area cannot receive effective satellite navigation signals.

[0051] In some embodiments, an RF transmitting module can be used to transmit the generated full-band interference signal to the target area, ensuring that the intensity of the interference signal is sufficient to cover the reception range of the UAV, thereby effectively shielding all satellite navigation signals in the target area, making the UAV unable to obtain effective navigation information, and thus achieving the purpose of navigation interference.

[0052] In the above embodiments, multi-frequency navigation signals are generated based on an FPGA, and time-division multiplexing and coherent interference technologies are used to comprehensively interfere with the satellite navigation system of the target UAV. Through steps such as precise clock generation, frequency division, pseudo-code generation, dynamic binding, modulation, frequency offset adjustment, and signal superposition, not only can interference signals matching multiple satellite systems be efficiently generated, but also a wide frequency band can be covered to provide a strong interference effect. At the same time, the system is efficient in using hardware resources. Through the parallel processing ability of the FPGA and time-division multiplexing technology, resource occupancy is reduced, enabling the system to be implemented on a smaller hardware platform.

[0053] It should be noted that in the embodiments of this application, the characteristics of time-division multiplexing and coherent interference are utilized, and an FPGA technology is combined to generate navigation suppression interference signals of 1.2 GHz and 1.5 GHz. In contrast, it is also possible to develop based on a DSP. This method is programmed through a high-level programming language (such as C language or MATLAB), and the development process is simpler, and modification and debugging are more convenient. However, the parallel processing effect of the DSP method is poor, it is difficult to achieve simultaneous interference of multiple frequency points, and problems may occur in terms of timing.

[0054] Referring to Figure 4 , as an embodiment of step S103, the steps of receiving the satellite identification list of the area where the target UAV is located, dividing time slices based on the frequency-divided clock signal, and cyclically generating a pseudo-code sequence matching the satellite identification list include: step S201, according to the satellite identification list of the area where the target UAV is located, based on the frequency-divided clock signal, dividing the total time into multiple time slices equal to the number of satellite identifications in the satellite identification list; Among them, the system receives the satellite identification list of the area where the target UAV is located. This list contains the IDs of all available satellites. Usually, these satellite IDs are from real-time or estimated data of the navigation system. The system will divide the total time into multiple time slices equal to the number of satellite IDs in the received satellite identification list based on the timing arrangement of the frequency-divided clock signal. The length of each time slice is determined by the number of target satellites.

[0055] Specifically, assume there are N satellites in the target area. The system divides the total time (e.g., T seconds) into N time slices, and the length of each time slice is T / N. Through this division method, the system can allocate a specific time slice to each satellite, and within this time slice, generate a pseudo-code sequence that matches the satellite ID. The basis for dividing the time slices is the frequency-divided clock signal, ensuring that the generation of each time slice matches the pseudo-code generation requirements of the satellite identification. For example, assume there are 32 satellites in the target area. The system will divide the time into 32 time slices within the total time T = 1 second, and the length of each time slice is 1 second / 32 = 0.03125 seconds. Within each time slice, the system generates a pseudo-code sequence that matches the satellite ID.

[0056] It can be understood that by effectively managing the timing of pseudo-code generation for different satellites, each satellite generates the corresponding pseudo-code sequence within an independent time slice, thus avoiding conflicts between satellite signals. Dividing the time slices and ensuring synchronization improves the system's ability to process multi-satellite signals, avoiding resource conflicts and calculation delays.

[0057] Step S202: Within each time slice, loop to generate the corresponding pseudo-code sequence according to the satellite identification list until the pseudo-code sequences of all satellite identifications are completed.

[0058] Among them, after the time slice division, the system will perform loop processing according to the satellite ID in the satellite identification list. Within each time slice, the system will generate a pseudo-code sequence corresponding to the current satellite ID. The process of generating the pseudo-code sequence includes generating a pseudo-code signal that meets the specifications according to parameters such as the satellite's identification, pseudo-code rate, and modulation method. The system loops through each satellite ID in the satellite identification list until the pseudo-code sequences of all satellites are completed.

[0059] Specifically, the generation of the pseudo-code sequence corresponding to each satellite ID is based on information such as the modulation method, pseudo-code type (such as cyclic shift code, ladder code, CDMA spreading code, etc.), and pseudo-code rate of the satellite. Within each time slice, the system sequentially generates the pseudo-code sequences of the corresponding satellites, completing the pseudo-code generation for each item in the satellite identification list. Through loop control, the system continuously checks the satellite ID and generates the pseudo-code sequence in order to ensure that the signals of all satellites are processed.

[0060] Exemplarily, assume there are 32 satellites in the target area. Within each time slice, the system will sequentially generate the corresponding pseudo-codes according to the satellite IDs in the satellite identification list. For example, the system first generates the pseudo-code sequence that matches satellite 1 within the first time slice, generates the pseudo-code sequence that matches satellite 2 within the second time slice, and so on, until the pseudo-code sequences of all 32 satellites are generated.

[0061] In the above embodiments, the system can efficiently divide time slices based on the satellite identification list in the target area using a frequency-divided clock signal, and cyclically generate a pseudo-code sequence that matches the satellite identification within each time slice. This technical solution effectively avoids conflicts and resource waste of multi-satellite signals, and ensures the synchronization and accuracy of the system when processing multi-satellite signals through time-division multiplexing technology. At the same time, by cyclically generating the pseudo-code sequence, it is ensured that the pseudo-code generation of each satellite is completed within an independent time window, thus avoiding overloading of the system and computational bottlenecks. This solution is efficient, scalable, and can generate and manage complex signals under limited hardware resources.

[0062] Referring to Figure 5 , in one embodiment of the present application, taking the time-division multiplexing of the GPS system as an example, when the receiver receives the ID numbers and the number of satellites in the sky, it sends them to the RAM. The GPS receiver usually processes navigation signals in units of 20 ms. To ensure that the switching time can completely suppress interference, five times the time, that is, 100 ms, is selected as a time slice. According to this principle, the number of satellites is multiplied by 100 ms to obtain the total time, and it is divided into time slices equal to the number of satellites. Each time slice corresponds to a small loop, and this small loop executes a pseudo-code generation method for a certain satellite ID. After the end of the large loop (12 hours), the satellite ID will be converted according to the remaining number of satellites. If the receiver does not read the satellite ID, it is assumed that the currently serving GPS satellite signal contains 32 ID numbers, and the total time is set to 3.2 s, which is divided into 32 time slices, and each time slice corresponds to a different satellite ID. The satellite IDs will increment sequentially and cycle.

[0063] As an embodiment of the pseudo-code sequence, the generation of the pseudo-code sequence includes: Generating a cyclic shift code through a cyclic shift register; the generating polynomial of the cyclic shift code is based on the Gold code structure of the target navigation system; Among them, the system generates a cyclic shift code through a cyclic shift register (LSFR, Linear Feedback Shift Register). LSFR is a common pseudo-random sequence generator that can generate sequences with good pseudo-random properties. In this step, the system generates a cyclic shift code that meets the requirements of the target navigation system by configuring the shift rule (such as the feedback polynomial) of the LSFR.

[0064] Specifically, the generation of the cyclic shift code depends on the Gold code structure of the target navigation system. The Gold code is a pseudo-random code obtained by performing an exclusive OR operation on two pseudo-random sequences of equal length. The LSFR can generate a sequence that matches the Gold code structure through the design of its feedback polynomial, thus ensuring the consistency of the properties of the pseudo-code with the target navigation system.

[0065] Generate a stepped code through the exclusive OR operation of the main code and the secondary code; the code lengths of the main code and the secondary code match the target navigation system; wherein, the system generates the stepped code through the exclusive OR operation of the main code and the secondary code, and the stepped code is a special pseudo-random sequence, usually obtained by the exclusive OR operation of two different sequences (the main code and the secondary code). The stepped code can be generated by selecting the main code and the secondary code that match the target navigation system and performing the exclusive OR operation.

[0066] Specifically, the generation of the stepped code mainly depends on the length of the main code and the secondary code matching the requirements of the target navigation system. In most navigation systems, the lengths of the main code and the secondary code are fixed and match the system's code rate, pseudo-code rate, and other navigation parameters. Through the exclusive OR operation, the system can generate a stepped code with specific sequence characteristics, enhancing the signal's spread spectrum effect.

[0067] Generate a CDMA spread spectrum code based on the spread spectrum modulation rule; the spread spectrum modulation rule includes the dynamic switching of the high-frequency modulation code and the low-frequency modulation code; Among them, the system generates a CDMA (Code Division Multiple Access) spread spectrum code based on the spread spectrum modulation rule. The generation rule of the CDMA spread spectrum code includes the dynamic switching of the high-frequency modulation code and the low-frequency modulation code. The high-frequency modulation code is used to increase the signal bandwidth, while the low-frequency modulation code is used to reduce the signal interference. The dynamic switching adjusts the signal bandwidth and anti-interference ability according to actual needs.

[0068] Specifically, the spread spectrum modulation rule uses modulation codes of different frequencies to control the signal bandwidth. In CDMA, multiple signals share the same frequency band for communication, so it is necessary to use spread spectrum codes to make each signal occupy an independent sub-band in the wideband, thus avoiding interference. Dynamically switching the high-frequency and low-frequency modulation codes can optimize the signal's spread spectrum effect according to conditions such as the signal-to-noise ratio and system bandwidth of the current environment.

[0069] Generate a military pseudo-code according to the truncation period and exclusive OR logic of the military navigation signal.

[0070] Among them, the system generates a military pseudo-code according to the truncation period and exclusive OR logic of the military navigation signal. Military pseudo-codes usually adopt high-strength security encryption and exclusive OR operations. Through special truncation period settings, the periodicity of the pseudo-code sequence is restricted, increasing its anti-interference ability and confidentiality.

[0071] Specifically, the generation of the military pseudo-code depends on a specific truncation period, which determines the reuse frequency of the pseudo-code sequence. The truncation period limits the length of the pseudo-code sequence, thus increasing the signal's security and complexity. The exclusive OR logic further increases the randomness of the pseudo-code, reducing the predictability of the military signal and enhancing the system's anti-interference ability.

[0072] In the above embodiments, according to the requirements of the target navigation system, the techniques of cyclic shift register, step code generation, CDMA spreading spectrum, and military pseudo-code generation are used to generate pseudo-code sequences that meet the requirements of navigation signals. These pseudo-code sequences not only ensure the spreading effect and anti-interference ability of navigation signals but also improve the encryption and security of signals.

[0073] In the embodiments of the present application, as an implementation manner of generating cyclic shift codes, the cyclic shift codes are generated bit by bit by the exclusive OR operation of a cyclic shift register. For example, for GPS-L1 and GLONASS-L1 signals, their pseudo-codes include three signal components: carrier, ranging code, and data code. Specifically, the carriers of GPS-L1 and GLONASS-L1 are GPS-L1 and GLONASS-L1, the ranging code is a common ranging code (C code), and the information rate and content of the data code (D code) vary according to different satellite types and carrier frequencies.

[0074] The common ranging code is generated in the form of a 1023-bit Gold code. Its generation process is to perform modulo-2 addition on two 11-stage m-sequences (G1 and G2) to generate a balanced Gold code, and then truncate it to generate a 1023-bit ranging code. Its generating polynomial is: Thirty-seven out of 1025 Gold codes are selected to correspond to different satellite IDs (satellites numbered 1-32 and satellites for other purposes).

[0075] Refer to Figure 6 , as an implementation manner of generating step codes, the exclusive OR operation of the main code and the sub-code generates step codes. The main code and sub-code of each signal component are stored in the ROM in the COE format. The depth of the main code is the number of satellite IDs multiplied by the code bits of the main code. Through the way of circularly reading the main code, the exclusive OR operation of the main code and the sub-code obtains the step code.

[0076] Among them, taking BDS-B1I as an example, converting it into a mathematical formula for calculation: The number of large cycle periods experienced by the main code is: The current index of the main code is: primary_code_index(n) = n - (primary_cycle_cnt(n) - 1) · primary_code_len When the main code completes one round of circulation, the sub-code starts to increment itself, and its number of periods is expressed as: The current index of the sub-code is: secondary_code_index(n) = primary_cycle_cnt(n) - (secondary_cycle_cnt(n) - 1) · secondary_code_len Data code generation (without sub - code modulation) is as follows: data_prn_code(n) = data_primary_code(primary_code_index(n)). Pilot code generation (including sub - code modulation) is as follows: pilot_prn_code(n) = xor(pilot_primary_code(primary_code_index(n)), pilot_secondary_code(secondary_code_index(n))) Where prn_len represents the total code length, primary_code_len represents the primary code length, secondary_code_len represents the sub - code (secondary code) length, data_primary_code(i) represents the data primary code sequence, pilot_primary_code(i) represents the pilot primary code sequence, pilot_secondary_code(j) represents the pilot secondary code sequence, and xor represents the bit - by - bit exclusive - OR operation.

[0077] Refer to Figure 7 , as an implementation method for generating CDMA spreading codes, perform a spreading operation on the ranging code generated by a shift register. After obtaining the spreading code, perform an exclusive - OR operation with the step code. The generation idea of the spreading code is as follows: Use a fast clock to generate each bit of the spreading code, and at the same time use a slow clock to read the navigation information code in the RAM. When the navigation information code needs to be spread, generate the corresponding high - frequency modulation code sequence to replace the original code value; otherwise, use a faster clock to read the navigation information code or generate a low - frequency modulation code sequence.

[0078] Among them, taking GPS - L1C as an example, converting it into a mathematical formula for calculation, the frequency of the GPS - L1C pilot code is 12 times that of the data code, and its rate - related definitions are as follows: Where pilot_freq is the pilot code frequency and prn_freq is the data code frequency; In each spreading segment, every 33 bits are divided into two modulation rules: Bits 0, 4, 6, 29: Use BOC(6,1) modulation, corresponding to the high - frequency code sequence, and the code sequence is: BOC(6,1) = [1,0,1,0,1,0,1,0,1,0,1,0] The remaining bits: modulated by BOC(1,1), corresponding to the low-frequency code sequence, and the code sequence is: BOC(1,1) = [1,1,1,1,1,1,0,0,0,0,0,0] If mod(i - 1, 33) ∈ {0, 4, 6, 29}, the pilot spreading code is: pilot_origin[12i - 11:12i] = pilot_prn_code(i) ⊕ BOC(6,1) Otherwise: pilot_origin[12i - 11:12i] = pilot_prn_code(i) ⊕ BOC(1,1).

[0079] As an implementation of generating military pseudo-code, taking the P(Y) code as an example, since the military modulation method is unknown and the structure is not public, but it can be confirmed that the P(Y) code in the military code is the W code generated by the exclusive OR of the P code and the W code. The specific details are classified, but it is known that the W code acts on the P code at a frequency of about 500 kHz (the rate of the W code changes according to a certain pattern).

[0080] The specific pattern is as follows: 20 P codes form one W code, lasting for 11 W codes; then, 22 P codes form one W code, lasting for 21 W codes of this cycle. Two W codes are combined into one H cycle, and 15 H cycles equal 1 millisecond. The natural periods of the four shift registers (X1A, X1B, X2A, X2B) of the P code are 4095, all of which are truncated and operate periodically according to a certain rule. The periods of X1A and X2A are truncated to 4092 chips, and the periods of X1B and X2B are truncated to 4093 chips.

[0081] The X1 sequence operates according to the following rule: X1A takes 4092 chips as one cycle and runs for 3750 complete cycles; X1B takes 4093 chips as one cycle, stops pushing after running 3749 cycles, restarts after X1A finishes running, and resets. X1B needs to wait for 343 clock chips (i.e., 4092×3750 - 4093×3749), and then load the initial phase to start running again.

[0082] X1 is obtained by the exclusive OR of X1A and X1B, and the calculation formula is: X1(n) = X1A(n) ⊕ X1B(n). The timing relationship between X2A and X2B in the X2 sequence is similar to that between X1A and X1B in the X1 sequence. The difference is that when X2A reaches the end of the 3750 cycle, X2A and X2B stop pushing simultaneously and resume after 37 chip clocks. That is, X2A needs to stop pushing for 37 chip clocks, and X2B needs to stop for 343 chip clocks plus 37 chip clocks, and then reload their respective initial phases and resume operation. X2 is obtained by the exclusive OR of X2A and X2B, and the calculation formula is: X2(n) = X2A(n) ⊕ X2B(n). Finally, the P code sequence is obtained by the exclusive OR of the X1 and X2 sequences. Each satellite uses this sequence for one week. At the output position of the X2 sequence, the X2 sequence is delayed by i chips using a shift register to form 37 different P code sequences. The calculation formula for the P code sequence is: P(n) = (X1A(n) ⊕ X1B(n)) ⊕ (X2A(n) ⊕ X2B(n)).

[0083] Referring to Figure 8 , as an implementation manner of step S106, the steps of performing frequency offset adjustment based on each frequency point in the multi-frequency navigation signal and superimposing to generate the full-band interference signal include: Step S301, performing complex multiplication on the navigation signal of each frequency point to generate a frequency offset signal; Among them, the system performs complex multiplication on the navigation signal of each frequency point to generate a frequency offset signal. The generation of the frequency offset signal is achieved by multiplying each navigation signal by a complex factor, which represents the magnitude and direction of the frequency offset. The use of complex multiplication can adjust both the amplitude and phase of the signal simultaneously, thereby achieving precise frequency offset control. The frequency offset signal is completed through this operation to ensure that the signal of each frequency point can be adjusted according to the required frequency offset amount.

[0084] Specifically, the adjustment of the frequency offset is achieved through complex multiplication. Assuming the original navigation signal is S(f) and the frequency offset factor is e jΔωt , the operation formula for complex multiplication is: S 偏 (f) = S(f) · e jΔωt ; Among them, Δω is the frequency offset amount, t is the time variable, S 偏 (f) is the signal after frequency offset adjustment, and e jΔωt is the complex factor used to achieve the frequency offset.

[0085] It can be understood that by generating the frequency offset signal through complex multiplication, the frequency offset of each signal can be precisely controlled, enabling the signal to adapt to different interference requirements, thereby ensuring the flexibility and accuracy of the frequency offset adjustment and enabling precise frequency adjustment during the generation of multi-frequency signals.

[0086] Step S302: Superimpose the frequency offset signals through an adder tree to generate a full-band interference signal that covers the satellite navigation of the target UAV.

[0087] Among them, after generating the frequency offset signals of each frequency point, the system superimposes these frequency offset signals through an adder tree to generate a full-band interference signal that covers the satellite navigation of the target UAV. The adder tree is an effective hardware structure that can combine multiple signals through layer-by-layer addition. Through the adder tree, the system can efficiently synthesize the frequency offset signals of each frequency point into a full-band interference signal, and this interference signal can generate interference within multiple frequency point ranges.

[0088] Exemplarily, the adder tree structure combines multiple input signals into one output signal in a recursive manner. Suppose there are N frequency offset signals S 偏1 (f), S 偏2 (f), S 偏3 (f), ……, S 偏N (f). The adder tree will superimpose these signals layer by layer, and the calculation formula is:

[0089] It can be understood that by superimposing multiple frequency offset signals through an adder tree, the system can efficiently synthesize a full-band interference signal, thereby reducing the consumption of computing resources and improving the generation speed while maintaining the system performance. The full-band interference signal can effectively cover multiple navigation frequency bands, ensuring that interference can be generated within the working frequency band of the UAV navigation signal and enhancing the effect of the interference signal.

[0090] The embodiment of the present application uses the principle of coherent interference to generate interference signals, suppresses the target satellite navigation signal through satellite navigation signals of a similar modulation method. Since the signals of the similar modulation method have similar spectral characteristics, it is difficult to distinguish the truly required signal when using a similar demodulation technique at the receiving end, so that the interference signal is more likely to affect the received signal. This technical solution makes full use of the parallel processing ability and timing control characteristics of the FPGA, and configures different satellite IDs cyclically through time-division multiplexing technology to generate interference signals for the five major satellite systems of GPS, BDS, GLONASS, QZSS, and Galileo. The system can cover eight different frequency points, covering the 1.2 GHz and 1.5 GHz frequency bands, including frequency points such as 1176.45 MHz, 1191.795 MHz, 1227.60 MHz, 1246.00 MHz, 1278.75 MHz, 1561.098 MHz, 1575.42 MHz, and 1602.00 MHz respectively.

[0091] It should be noted that the signals of GLONASS can be mixed according to multiple different satellite numbers and satellite IDs, and the number and frequency points of the signals can be replaced and customized according to actual requirements and hardware requirements.

[0092] In the actual application process, through time-division multiplexing, the technical solution of this application enables the system to generate multiple satellite interference signals in parallel, widely covering different frequency bands. The system supports multiple satellite types, occupies less resources, has a high degree of integration, and broad application prospects.

[0093] The embodiment of this application also discloses a UAV satellite navigation interference signal generation system based on FPGA.

[0094] A UAV satellite navigation interference signal generation system based on FPGA, the system includes: A clock generation module, configured to generate a reference clock signal according to the pseudocode rate requirement of the target navigation system and perform frequency division processing to obtain multiple divided clock signals; In the embodiment of this application, the clock generation module consists of a control clock and a pseudocode clock. Since the pseudocode rates of different navigation signals are different, this module provides different pseudocode clocks for each satellite signal (such as GPS, BDS, GLONASS, QZSS, GALILEO), and uses the control clock to ensure that all signals can be generated synchronously. By calculating the least common multiple of each pseudocode clock, a total clock is generated, and then through the frequency division method, an input is provided for each pseudocode generation module, saving resources.

[0095] A pseudocode sequence generation module, configured to receive a satellite identification list of the area where the target UAV is located, divide time slices based on the divided clock signals, and cyclically generate a pseudocode sequence matching the satellite identification list; A modulation module, configured to obtain satellite navigation message data and perform dynamic binding according to the satellite identification and the pseudocode sequence, and generate multi-frequency navigation signals according to the modulation rules; A mixing and superposition module, configured to perform frequency offset adjustment based on each frequency point in the multi-frequency navigation signal, and superpose and generate a full-band interference signal; A radio frequency transmitting module, configured to transmit the full-band interference signal to the area where the target UAV is located; the full-band interference signal is used to cover the working frequency band of the satellite navigation receiver of the target UAV.

[0096] As an implementation manner of the pseudocode sequence generation module, the pseudocode sequence generation module includes multiple parallel pseudocode generation units, and each pseudocode generation unit generates a pseudocode sequence of different satellite identifications according to time-division multiplexing logic; In the embodiments of the present application, the pseudo-code generation module is mainly used to generate pseudo-codes corresponding to different satellite IDs for the five major satellite systems of GPS, BDS, GLONASS, QZSS, and Galileo. The types of pseudo-codes include stepped codes, PRN codes, CM codes, CL codes, curved codes, Gold codes, etc. The pseudo-code generation methods for each satellite are different, and the differences in satellite IDs will also lead to differences in pseudo-code generation.

[0097] Specifically, the pseudo-code generation unit includes: A cyclic shift code generator, which is used to output cyclic shift codes based on the generating polynomial of the Gold code structure; A stepped code generator, which is used to generate stepped codes through the exclusive OR operation of the main code and the secondary code; the code lengths of the main code and the secondary code match the target navigation system; A CDMA spreading code generator, which dynamically switches to generate CDMA spreading codes according to the high-frequency / low-frequency modulation rules; A military pseudo-code generator, which generates military pseudo-codes based on the truncated period and exclusive OR logic.

[0098] As an implementation manner of the mixing and superposition module, the mixing and superposition module includes: A complex multiplier, which is used to perform complex multiplication operations on the navigation signals of each frequency point to generate frequency offset signals; An adder tree structure, which is used to superimpose the frequency offset signals through the adder tree to generate a full-band interference signal covering the satellite navigation of the target UAV.

[0099] In the present application, different satellite IDs are generated through time-division multiplexing, reducing the number of parallel channel instantiations, greatly reducing the resource utilization rate, and enabling the system to be successfully deployed on a small board (such as an AD9361+ZYNQ7020 board). At the same time, the system supports multi-frequency points (1.2 GHz frequency band: 1176.45 MHz, 1191.795 MHz, 1227.60 MHz, 1246.00 MHz, 1278.75 MHz; 1.5 GHz frequency band: 1561.098 MHz, 1575.42 MHz, 1602.00 MHz) and multi-navigation systems (GPS, QZSS, GALILEO, GLONASS, BDS) to send simultaneously, and can suppress the existing UAV navigation satellite frequency points. This system can achieve direct interference in the full-band range of UAV navigation satellites without dividing sub-frequency bands.

[0100] In addition, military pseudo-codes are generated using the properties of P-codes and W-codes, a jamming signal with the same spectrum as the military navigation signal is generated, and the military navigation message interface is stored in the RAM, which has strong subsequent expandability. The entire system generates various pseudo-codes entirely based on the FPGA, with high modulation efficiency. By replacing multiplication with bitwise exclusive OR and after delay alignment, high and low levels are used to determine assignments, thereby significantly reducing the utilization rate of computing resources.

[0101] The UAV satellite navigation jamming signal generation system based on FPGA according to the embodiment of the present application can implement any one of the above UAV satellite navigation jamming signal generation methods, and the specific working processes of each module in the UAV satellite navigation jamming signal generation system can refer to the corresponding processes in the above method embodiments.

[0102] In several embodiments provided in the present application, it should be understood that the provided methods and systems can be implemented in other ways. For example, the system embodiments described above are merely illustrative; for example, the division of a certain module is only a logical function division, and there may be other division methods in actual implementation. For example, multiple modules can be combined or integrated into another system, or some features can be ignored or not executed.

[0103] The embodiment of the present application also discloses a computer device.

[0104] The computer device includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, it implements a UAV satellite navigation jamming signal generation method based on FPGA as described above.

[0105] The embodiment of the present application also discloses a computer-readable storage medium.

[0106] The computer-readable storage medium stores a computer program that can be loaded and executed by a processor to implement any one of the above UAV satellite navigation jamming signal generation methods based on FPGA.

[0107] Among them, the computer-readable storage medium can be any tangible medium that contains or stores a program, and this program can be used by or in combination with an instruction execution system, apparatus, or device; the program code contained on the computer-readable medium can be transmitted using any appropriate medium, including but not limited to wireless, wire, optical cable, RF, etc., or any suitable combination of the above.

[0108] It should be noted that in the above embodiments, the descriptions of each embodiment have their own emphases. For parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0109] The above are all preferred embodiments of the present application, and do not limit the protection scope of the present application accordingly. Any feature disclosed in this specification (including the abstract and drawings), unless specifically described, can be replaced by other equivalent or similar-purpose alternative features. That is, unless specifically described, each feature is only an example of a series of equivalent or similar features.

Claims

1. A method for generating an interference signal for UAV satellite navigation based on FPGA, characterized in that, The method includes: Generating a reference clock signal according to the pseudo-code rate requirement of the target navigation system; Performing frequency division processing according to the reference clock signal to obtain a plurality of divided clock signals; Receiving a list of satellite identifiers in the area where the target UAV is located, dividing time slices based on the divided clock signals, and cyclically generating a pseudo-code sequence matching the list of satellite identifiers; Obtaining satellite navigation message data and dynamically binding it with the pseudo-code sequence according to the satellite identifier; Generating a multi-frequency navigation signal according to the modulation rule with the bound satellite navigation message data and pseudo-code sequence; Performing frequency offset adjustment based on each frequency point in the multi-frequency navigation signal and superimposing to generate a full-band interference signal; Transmitting the full-band interference signal to the area where the target UAV is located; the full-band interference signal is used to cover the operating frequency band of the satellite navigation receiver of the target UAV.

2. The method for generating a drone satellite navigation interference signal based on FPGA according to claim 1, wherein, The steps of receiving a list of satellite identifiers in the area where the target UAV is located, dividing time slices based on the divided clock signals, and cyclically generating a pseudo-code sequence matching the list of satellite identifiers include: Based on the list of satellite identifiers in the area where the target UAV is located and the divided clock signals, dividing the total time into a plurality of time slices equal to the number of satellite identifiers in the list of satellite identifiers; Cyclically generating a corresponding pseudo-code sequence according to the list of satellite identifiers within each time slice until the pseudo-code sequences of all satellite identifiers are generated.

3. A method for generating an interference signal for UAV satellite navigation based on FPGA according to claim 2, characterized in that, The pseudo-code sequence includes a cyclic shift code, a stepped code, a CDMA spreading code, and a military pseudo-code.

4. A method for generating a drone satellite navigation interference signal based on FPGA according to claim 3, wherein, The generation of the pseudo-code sequence includes: Generating a cyclic shift code through a cyclic shift register; the generation polynomial of the cyclic shift code is based on the Gold code structure of the target navigation system; Generating a stepped code through the exclusive OR operation of a main code and a sub-code; the code lengths of the main code and the sub-code match the target navigation system; Generating a CDMA spreading code based on the spread spectrum modulation rule; the spread spectrum modulation rule includes the dynamic switching of a high-frequency modulation code and a low-frequency modulation code; Generating a military pseudo-code according to the truncation period and exclusive OR logic of the military navigation signal.

5. A method for generating a drone satellite navigation interference signal based on FPGA according to claim 1, characterized in that, The steps of performing frequency offset adjustment based on each frequency point in the multi-frequency navigation signal and superimposing to generate a full-band interference signal include: Performing a complex multiplication operation on the navigation signal of each frequency point to generate a frequency offset signal; Superimposing the frequency offset signals through an adder tree to generate a full-band interference signal covering the satellite navigation of the target UAV.

6. A UAV satellite navigation interference signal generation system based on FPGA, characterized in that, The system includes: A clock generation module, configured to generate a reference clock signal according to the pseudo-code rate requirement of the target navigation system and perform frequency division processing to obtain a plurality of divided clock signals; A pseudo-code sequence generation module, configured to receive a list of satellite identifiers in the area where the target UAV is located, divide time slices based on the divided clock signals, and cyclically generate a pseudo-code sequence matching the list of satellite identifiers; A modulation module, configured to obtain satellite navigation message data and dynamically bind it with the pseudo-code sequence according to the satellite identifier, and generate a multi-frequency navigation signal according to the modulation rule; A mixing and superimposing module, configured to perform frequency offset adjustment based on each frequency point in the multi-frequency navigation signal and superimpose to generate a full-band interference signal; The radio frequency transmitting module is used to transmit the full-band interference signal to the area where the target UAV is located; the full-band interference signal is used to cover the working frequency band of the satellite navigation receiver of the target UAV.

7. The drone satellite navigation interference signal generation system based on FPGA according to claim 6, characterized in that: The pseudo-code sequence generation module includes a plurality of parallel pseudo-code generation units, and each pseudo-code generation unit generates a pseudo-code sequence with different satellite identifiers according to time-division multiplexing logic; The pseudo-code generation unit includes: A cyclic shift code generator, which is used to output a cyclic shift code based on the generating polynomial of the Gold code structure; A stepped code generator, which is used to generate a stepped code through the exclusive OR operation of the main code and the sub-code; the code lengths of the main code and the sub-code match the target navigation system; A CDMA spreading code generator, which dynamically switches to generate a CDMA spreading code according to the high-frequency / low-frequency modulation rule; A military pseudo-code generator, which generates a military pseudo-code based on the truncated period and exclusive OR logic.

8. The system for generating UAV satellite navigation interference signals based on FPGA according to claim 6, characterized in that, The mixing and superposition module includes: A complex multiplier, which is used to perform complex multiplication operations on the navigation signals of each frequency point to generate a frequency offset signal; An adder tree structure, which is used to superpose the frequency offset signals through an adder tree to generate a full-band interference signal covering the satellite navigation of the target UAV.

9. A computer device, characterized in that: It includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, it implements the method according to any one of claims 1 to 5.

10. A computer-readable storage medium, characterized in that: A computer program is stored that can be loaded and executed by a processor to implement the method according to any one of claims 1 to 5.

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