Anti-interference filter based on FFT (Fast Fourier Transform) and interference suppression method thereof

Abstract

The invention discloses an anti-interference filter based on FFT (Fast Fourier Transform), and relates to the field of GNSS (Global Navigation Satellite System) receivers. A radio frequency front end is used for receiving GNSS signals and down-converting the GNSS signals into IF (Intermediate Frequency); the analog-to-digital converter ADC is used for converting the GNSS signal which is received by the radio frequency front end and moved to the intermediate frequency into a digital signal; and the anti-interference filter is used for converting the digital signal from time domain representation to frequency domain representation, eliminating an interference signal in a preset frequency range in a frequency domain according to a preset demand index, and inversely transforming the frequency domain signal subjected to interference elimination back to the time domain. The invention further discloses an interference suppression method of the anti-interference filter based on the FFT, the anti-interference filter based on the FFT is suitable for various GNSS receivers, the anti-interference performance of the receivers can be effectively improved, and the accuracy of navigation and positioning is ensured.

Description

Technical Field

[0001] The present invention relates to the field of global navigation satellite system (GNSS) receivers, and in particular to an anti-interference filter based on FFT and an interference suppression method thereof. Background Art

[0002] Global Navigation Satellite System (GNSS) receivers play a vital role in various fields, from aviation, aerospace, surveying and mapping to agriculture, military, etc. However, because the signal strength received by GNSS receivers is very small, a major disadvantage of GNSS receivers is that they are susceptible to various interference signals, especially within the GNSS frequency band.

[0003] There are many types of interference, including natural interference, unintentional interference and intentional interference. Among them, interference refers to the deliberate emission of in-band electromagnetic radiation, which can block GNSS signals and is equivalent to a denial of service attack. Spoofing is another interference technique, which records the real GNSS signal, modifies it, and then retransmits it as if it is the original signal, thereby misleading the GNSS receiver to make an incorrect reading.

[0004] Interference mitigation algorithms have become a common feature in GNSS receiver designs for both professional and mass market applications to combat both unintentional and intentional (jamming) interference. GNSS receivers are susceptible to various interference signals such as continuous wave interference (CWI), pulsed CWI, and swept frequency interference. Traditional anti-jamming techniques such as adaptive notch filters, empirical mode decomposition (EMD), and blind source separation (BSS) can provide some protection but cannot meet the high reliability requirements of military, aviation, and emergency services. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide an FFT-based anti-interference filter and an interference suppression method thereof, wherein the anti-interference filter implemented by the fast Fourier transform (FFT) is used to reduce the impact of interference in the GNSS receiver and improve the reliability of its positioning, navigation and timing (PVT) services. The present invention greatly improves the scalability of the GNSS chip, improves the estimation accuracy and dynamic adaptation range of parameters in challenging scenarios through the control interface of the external code NCO and the carrier NCO, and provides a powerful platform support for the combined navigation system based on the GNSS chip.

[0006] The present invention adopts the following technical solutions to solve the above technical problems:

[0007] In a first aspect, an anti-interference filter based on FFT proposed in the present invention includes a radio frequency front end and an analog-to-digital converter ADC, and also includes an anti-interference filter, wherein:

[0008] RF front end, used for receiving GNSS signals and down-converting GNSS signals to intermediate frequency IF;

[0009] Analog-to-digital converter (ADC), used to convert the GNSS signal received by the RF front end and moved to the intermediate frequency into a digital signal;

[0010] The anti-interference filter is used to convert the digital signal from the time domain representation to the frequency domain representation, and eliminate the interference signal within the preset frequency range in the frequency domain according to the theoretical spectrum distribution, and inversely transform the frequency domain signal with interference eliminated back to the time domain.

[0011] As a further optimization scheme of an FFT-based anti-interference filter described in the present invention, the anti-interference filter includes a window function generator, an FFT core, a threshold calculator, an interference elimination unit and an IFFT core, wherein:

[0012] A window function generator is used to select a window function and generate a window function with the same number of points as the fast Fourier transform FFT;

[0013] FFT core, used to perform fast Fourier transform on digital signals based on window function;

[0014] a threshold calculator, for calculating a threshold value according to an energy level within a preset frequency range in the intermediate frequency signal;

[0015] An interference elimination unit, used to eliminate interference signals within a preset frequency range in the frequency domain according to a threshold;

[0016] The IFFT core is used to inversely transform the interference-eliminated frequency domain signal back to the time domain.

[0017] As a further optimization scheme of the FFT-based anti-interference filter described in the present invention, the threshold calculator includes a median calculator and a multiplier, wherein:

[0018] A median calculator, used to calculate the median of all frequency domain signals within a preset frequency range in the intermediate frequency signal after obtaining a preset filtering range;

[0019] The multiplier is used to multiply the calculated median by a proportional coefficient to determine a threshold value.

[0020] As a further optimization scheme of the FFT-based anti-interference filter described in the present invention, the interference elimination unit includes a comparator and a zero value setter, wherein:

[0021] A comparator for comparing the energy level of each frequency point in the frequency domain with a threshold value;

[0022] Zero value setter, used to set the energy of frequency points exceeding the threshold to zero.

[0023] As a further optimization scheme of the FFT-based anti-interference filter described in the present invention, it also includes a delay unit, which is used to delay the digital signal and input the delayed digital signal into the FFT core. The delay unit is used to compensate for the FFT processing time.

[0024] As a further optimization scheme of the FFT-based anti-interference filter described in the present invention, it also includes a merging unit, which is used to merge the interference-eliminated time domain signal with the unprocessed signal.

[0025] In a second aspect, an interference suppression method of an anti-interference filter based on FFT includes:

[0026] Receive GNSS signals and down-convert the GNSS signals to an intermediate frequency IF;

[0027] Convert the GNSS signal moved to the intermediate frequency into a digital signal;

[0028] The digital signal is converted from the time domain representation to the frequency domain representation, and the interference signal within the preset frequency range in the frequency domain is eliminated according to the preset demand index, and the interference-eliminated frequency domain signal is reversely transformed back to the time domain.

[0029] As a further optimization scheme of the interference suppression method of the FFT-based anti-interference filter described in the present invention, the digital signal is converted from the time domain representation to the frequency domain representation, and the interference signal within the preset frequency range in the frequency domain is eliminated according to the theoretical spectrum distribution, and the frequency domain signal with interference eliminated is inversely transformed back to the time domain; specifically as follows:

[0030] The mixed digital signal of the input satellite signal and the interference signal is divided into two data streams: a first data stream A and a second data stream B, wherein the second data stream B is a delay of the first data stream A;

[0031] Determine the type and size of the window function, multiply the window function by the first data stream A and the second data stream B respectively, and then perform a fast Fourier transform FFT to obtain frequency domain results of the first data stream A and the second data stream B;

[0032] After obtaining the frequency domain of the first data stream A and the second data stream B, interference suppression is performed on them, an interference suppression range is determined, and a signal after interference suppression and the amount of data from which interference is eliminated are output;

[0033] Determine a threshold value, and eliminate interference signals within a preset frequency range in the frequency domain according to the threshold value to obtain a satellite signal after interference suppression;

[0034] The first data stream A and the second data stream B are converted back to the time domain by using inverse Fourier transform, and the satellite signals after interference suppression are re-spliced ​​to re-merge the first data stream A and the second data stream B.

[0035] In a third aspect, an embodiment of the present invention further provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, wherein when the processor executes the computer program, the steps of the interference suppression method of the FFT-based anti-interference filter are implemented as in the above-mentioned second aspect or any corresponding embodiment thereof.

[0036] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the steps of the interference suppression method of the FFT-based anti-interference filter as described in the above-mentioned second aspect or any corresponding embodiment.

[0037] Compared with the prior art, the present invention adopts the above technical solution and has the following technical effects:

[0038] (1) The filtering performance of the invention is better. Traditional software simulation methods, such as adaptive notch filters, empirical mode decomposition, wavelet filtering, etc., have achieved certain results in suppressing interference, but they often have limitations. For example, the adaptive notch filter has limited performance improvement and high power consumption; the algorithm complexity of empirical mode decomposition and blind source separation is high, the amount of calculation is large, and it is difficult to achieve real-time processing; the complexity of wavelet filtering is high and the processing time is very long. The FFT elimination algorithm proposed in the present invention can effectively suppress various types of interference, including narrowband interference, broadband interference, continuous wave interference, pulse continuous wave interference and swept frequency interference.

[0039] (2) The hardware resource utilization of the invention is greatly improved compared with the traditional method. The invention proposes two FPGA hardware implementation schemes: fixed point and floating point. By analyzing the impact of different precisions on performance and selecting the optimal hardware design scheme, it is possible to minimize the consumption of hardware resources while ensuring performance, thus saving limited hardware resources.

[0040] (3) The invention is highly scalable. The FFT elimination algorithm and FPGA design scheme proposed in the invention can be applied to different GNSS receivers and can be adjusted according to different interference environments and hardware platforms, and has good scalability. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is the flow chart of the implementation of FFT interference suppression method;

[0042] Figure 2It is a flow chart of the interference suppression method implementation. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0044] like Figure 1 This is the flow chart of the FFT interference suppression method implementation. Figure 2 The invention is a flow chart of the interference suppression method. An anti-interference filter based on FFT includes a radio frequency front end and an analog-to-digital converter ADC, and also includes an anti-interference filter, wherein:

[0045] RF front end, used for receiving GNSS signals and down-converting GNSS signals to intermediate frequency IF;

[0046] Analog-to-digital converter (ADC), used to convert the GNSS signal received by the RF front end and moved to the intermediate frequency into a digital signal;

[0047] The anti-interference filter is used to convert the digital signal from the time domain representation to the frequency domain representation, and eliminate the interference signal within the preset frequency range in the frequency domain according to the preset theoretical spectrum distribution, and transform the interference-eliminated frequency domain signal back to the time domain.

[0048] The anti-interference filter includes a window function generator, an FFT core, a threshold calculator, an interference elimination unit and an IFFT core, wherein:

[0049] A window function generator is used to select a window function and generate a window function with the same number of points as the fast Fourier transform FFT;

[0050] FFT core, used to perform fast Fourier transform on digital signals based on window function;

[0051] a threshold calculator, for calculating a threshold value according to an energy level within a preset frequency range in the intermediate frequency signal;

[0052] An interference elimination unit, used to eliminate interference signals within a preset frequency range in the frequency domain according to a threshold;

[0053] The IFFT core is used to inversely transform the interference-eliminated frequency domain signal back to the time domain.

[0054] The threshold calculator includes a median calculator and a multiplier, wherein:

[0055] A median calculator, used to calculate the median of all frequency domain signals within a preset frequency range in the intermediate frequency signal after obtaining a preset filtering range;

[0056] The multiplier is used to multiply the calculated median by a proportional coefficient to determine a threshold value.

[0057] The interference elimination unit includes a comparator and a zero value setter, wherein,

[0058] A comparator for comparing the energy level of each frequency point in the frequency domain with a threshold value;

[0059] Zero value setter, used to set the energy of frequency points exceeding the threshold to zero.

[0060] The present invention also includes a delay unit, which is used to delay the digital signal, input the delayed digital signal into the FFT core, and the delay unit is used to compensate the FFT processing time. It also includes a merging unit, which is used to merge the interference-eliminating time domain signal with the unprocessed signal.

[0061] An interference suppression method of an anti-interference filter based on FFT, comprising:

[0062] Receive GNSS signals and down-convert the GNSS signals to an intermediate frequency IF;

[0063] Convert the GNSS signal moved to the intermediate frequency into a digital signal;

[0064] The digital signal is converted from the time domain representation to the frequency domain representation, and the interference signal within the preset frequency range in the frequency domain is eliminated according to the preset demand index, and the interference-eliminated frequency domain signal is reversely transformed back to the time domain.

[0065] The digital signal is converted from the time domain representation to the frequency domain representation, and the interference signal within the preset frequency range in the frequency domain is eliminated according to the theoretical spectrum distribution, and the interference-eliminated frequency domain signal is inversely transformed back to the time domain; the details are as follows:

[0066] The mixed digital signal of the input satellite signal and the interference signal is divided into two data streams: a first data stream A and a second data stream B, wherein the second data stream B is a delay of the first data stream A;

[0067] Determine the type and size of the window function, multiply the window function by the first data stream A and the second data stream B respectively, and then perform a fast Fourier transform FFT to obtain frequency domain results of the first data stream A and the second data stream B;

[0068] After obtaining the frequency domain of the first data stream A and the second data stream B, interference suppression is performed on them, an interference suppression range is determined, and a signal after interference suppression and the amount of data from which interference is eliminated are output;

[0069] Determine a threshold value, and eliminate interference signals within a preset frequency range in the frequency domain according to the threshold value to obtain a satellite signal after interference suppression;

[0070] The first data stream A and the second data stream B are converted back to the time domain by using inverse Fourier transform, and the satellite signals after interference suppression are re-spliced ​​to re-merge the first data stream A and the second data stream B.

[0071] The FFT removal algorithm proposed in the present invention is responsible for suppressing interference in GNSS receiver signals. The algorithm requires three external input signals and finally generates two output signals. The external input signals include the input path, output path and specific parameter settings of the signal. The input is a mixture of satellite signals and interference signals, and the output is a satellite signal after interference suppression. The key parameter settings include the main GNSS receiver settings, such as processing time, sampling frequency, interference start time and number of channels. The specific implementation method is as follows:

[0072] 1. First, you need to calculate the size of each sub-block and the number of sub-blocks. The size of the block is determined based on the size of the FFT. For example, a 1024-point FFT means that one block processes 1024 data points. Then, the number of blocks is specified based on the processing time of the interference suppression algorithm. For example, if the processing time is 10,000 milliseconds, this means that the number of blocks will be equal to 253,906. The calculation formula is as follows:

[0073]

[0074] Where mstoprocess is the processing time of the algorithm in milliseconds, fs is 26MHz, and blocksize is the size of the FFT, which is 1024. One is subtracted to account for the 50% overlap. We then multiply blocksize by 1.5 to account for the 50% overlap that occurs in the second branch, so the total range size becomes 1 to 1536 due to the additional 512 to 1024 points. This overlap is to avoid data loss and also to reduce the signal attenuation effect of the window on the output signal-to-noise ratio.

[0075] 2. After calculating the size and number of sub-blocks, the input data needs to be divided into two data streams. Let the first data stream be data stream A, which runs from the 1st data point to the 1024th data point of the block. The second data stream is data stream B. This data stream is a delayed version of data stream A, delayed by 50%, that is, from the 512th data point to the 1536th data at the end.

[0076] 3. Next, you need to determine the type and size of the window function. The size of the window function is easy to determine, as long as it is consistent with the number of points for FFT. The choice of the window function type needs to be considered from many aspects. It is necessary to consider the window function's suppression effect on background noise and interference, and also to consider that the window function itself will have a certain impact on the signal-to-noise ratio. In general, the Hamming window works better when dealing with multiple interference sources because it only removes a small amount of available spectrum. When there are only one or two interference sources, the Hanning window and the Black Hammans window can perform better because of their better interference suppression effect. Now take the Hamming window as an example. Since the FFT point number is 1024, the window function is a 1024-point Hamming window. Multiply the window function with data streams A and B respectively, and then perform a fast Fourier transform (FFT) to obtain the frequency domain results of data streams A and B.

[0077] 4. After obtaining the frequency domain of data stream A and data stream B, interference suppression is required. The interference suppression algorithm will output the signal after interference suppression and the amount of interference data removed. After obtaining the frequency domain content of data streams A and B, the interference suppression range needs to be determined. For the GPS L1 frequency band, interference suppression is performed within the center frequency of 3MHz. After specifying the frequency range of 5MHz to 8MHz and -8MHz to -5MHz, it is stored in an array for preservation.

[0078] 5. After determining the frequency band for interference suppression, it is necessary to determine a threshold value to identify and suppress interference, that is, functions that exceed the value set by the threshold value will be judged as interference and cleared to 0 or suppressed. For the selection of the threshold value, it is necessary to weigh the interference elimination effect and the degree of signal distortion. If the threshold value is set too high, the interference will pass through without being suppressed. If the threshold value is set too low, the original data will be removed together with the interference. The threshold selection scheme determined by the present invention is to multiply the mean of the selected frequency band by 4 as the threshold value, which ensures the performance while making the calculation less complicated and ensuring the real-time performance of the algorithm.

[0079] 6. After the interference suppression algorithm is processed, data stream A and data stream B are converted back to the time domain using the inverse Fourier transform, and data splicing is performed again according to the output of the interference suppression algorithm to re-merge data stream A and data stream B. The specific merging method is that if interference is found in data stream A or data stream B, the first half of the output (the 0th data point to the 512th data point) is filled by the center of stream A (the 256th data point to the 768th data point), and the second half of the output (the 512th data point to the 1024th data point) is filled by the center of data stream B (the 256th data point to the 768th data point). If no interference is found, the middle part of the input data (the 256th data point to the 1280th data point) is directly passed to the output data, that is, the entire interference suppression process is completed.

[0080] This paper proposes an FFT-based interference suppression technique that can provide significant improvements to current receiver performance. The proposed method can handle different levels of (J / No) and two types of narrowband jammers, namely continuous wave (CW) jammers and swept frequency jammers. Previous researchers have shown the performance impact of this method in software development, but no one has implemented the algorithm because of its complexity and the significant hardware resources required for hardware implementation. The purpose of this work is to prove that it can now be effectively implemented and utilized using fixed-point implementations in current FPGAs. This makes the proposed method using 1024-point FFTs feasible and feasible to obtain the required performance and hardware resources. The results show that this method is very robust and can handle different levels of interference while maintaining the required ((C / No) ~ = 40dB). The algorithm is implemented using VHDL in order to be uploaded to FPGA for hardware implementation. There are two designs for the hardware implementation, namely fixed-point design and floating-point design. Each design is verified and compared with the algorithm developed in MATLAB. The floating-point design uses more hardware resources but provides the best performance. However, the 22-bit fixed-point design provides performance very close to that of the floating-point design while using fewer hardware resources. Therefore, a 22-bit FFT blocking algorithm was chosen as the best design and compromise.

[0081] An embodiment of the present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and capable of running on the processor, wherein the processor implements the steps of the interference suppression method of the FFT-based anti-interference filter of any embodiment when executing the computer program.

[0082] An embodiment of the present invention further provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the interference suppression method of the FFT-based anti-interference filter of any embodiment.

[0083] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The schemes in the embodiments of the present invention may be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0084] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0085] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0086] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0087] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0088] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. An anti-interference filter based on FFT, comprising a radio frequency front end and an analog-to-digital converter ADC, characterized in that: It also includes an anti-interference filter, where RF front end, used for receiving GNSS signals and down-converting GNSS signals to intermediate frequency IF; Analog-to-digital converter (ADC), used to convert the GNSS signal received by the RF front end and moved to the intermediate frequency into a digital signal; The anti-interference filter is used to convert the digital signal from the time domain representation to the frequency domain representation, and eliminate the interference signal within the preset frequency range in the frequency domain according to the theoretical spectrum distribution, and inversely transform the frequency domain signal with interference eliminated back to the time domain.

2. The FFT-based anti-interference filter according to claim 1, characterized in that: The anti-interference filter includes a window function generator, an FFT core, a threshold calculator, an interference elimination unit and an IFFT core, wherein: A window function generator is used to select a window function and generate a window function with the same number of points as the fast Fourier transform FFT; FFT core, used to perform fast Fourier transform on digital signals based on window function; a threshold calculator, for calculating a threshold value according to an energy level within a preset frequency range in the intermediate frequency signal; An interference elimination unit, used to eliminate interference signals within a preset frequency range in the frequency domain according to a threshold; The IFFT core is used to inversely transform the interference-eliminated frequency domain signal back to the time domain.

3. The FFT-based anti-interference filter according to claim 2, characterized in that: The threshold calculator includes a median calculator and a multiplier, wherein: A median calculator, used to calculate the median of all frequency domain signals within a preset frequency range in the intermediate frequency signal after obtaining a preset filtering range; The multiplier is used to multiply the calculated median by a proportional coefficient to determine a threshold value.

4. The FFT-based anti-interference filter according to claim 2, characterized in that: The interference elimination unit includes a comparator and a zero value setter, wherein, A comparator for comparing the energy level of each frequency point in the frequency domain with a threshold value; Zero value setter, used to set the energy of frequency points exceeding the threshold to zero.

5. The FFT-based anti-interference filter according to claim 2, characterized in that: It also includes a delay unit, which is used to delay the digital signal and input the delayed digital signal into the FFT core. The delay unit is used to compensate for the FFT processing time.

6. The FFT-based anti-interference filter according to claim 2, characterized in that: The system also includes a merging unit, which is used to merge the interference-eliminated time domain signal with the unprocessed signal.

7. An interference suppression method of an anti-interference filter based on FFT, characterized in that: include: Receive GNSS signals and down-convert the GNSS signals to an intermediate frequency IF; Convert the GNSS signal moved to the intermediate frequency into a digital signal; The digital signal is converted from the time domain representation to the frequency domain representation, and the interference signal within the preset frequency range in the frequency domain is eliminated according to the preset demand index, and the interference-eliminated frequency domain signal is reversely transformed back to the time domain.

8. The interference suppression method of the FFT-based anti-interference filter according to claim 7, characterized in that: The digital signal is converted from the time domain representation to the frequency domain representation, and the interference signal within the preset frequency range in the frequency domain is eliminated according to the theoretical spectrum distribution, and the interference-eliminated frequency domain signal is inversely transformed back to the time domain; the details are as follows: The mixed digital signal of the input satellite signal and the interference signal is divided into two data streams: a first data stream A and a second data stream B, wherein the second data stream B is a delay of the first data stream A; Determine the type and size of the window function, multiply the window function by the first data stream A and the second data stream B respectively, and then perform a fast Fourier transform FFT to obtain frequency domain results of the first data stream A and the second data stream B; After obtaining the frequency domain of the first data stream A and the second data stream B, interference suppression is performed on them, an interference suppression range is determined, and a signal after interference suppression and the amount of data from which interference is eliminated are output; Determine a threshold value, and eliminate interference signals within a preset frequency range in the frequency domain according to the threshold value to obtain a satellite signal after interference suppression; The first data stream A and the second data stream B are converted back to the time domain by using inverse Fourier transform, and the satellite signals after interference suppression are re-spliced ​​to re-merge the first data stream A and the second data stream B.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that: When the processor executes the computer program, the steps of the interference suppression method of the FFT-based anti-interference filter are implemented as described in any one of claims 7 to 8.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the interference suppression method of the FFT-based anti-interference filter are implemented as described in any one of claims 7 to 8.

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