SAR radar jamming method based on high-speed data transmission
Data is transmitted to the programmable logic section via a high-speed serial interface, and pulse descriptors are extracted and processed in real time to reconstruct the baseband waveform of coherent interference signals. This solves the problems of data transmission rate bottleneck and timing lag in the existing technology, and realizes real-time and accurate processing of high-speed SAR radar interference signals.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ANHUI XINGTAIYU TECH CO LTD
- Filing Date
- 2026-04-09
- Publication Date
- 2026-06-26
Smart Images
Figure CN121995327B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of high-speed transmission technology for radar jamming, and in particular to a SAR radar jamming method based on high-speed data transmission. Background Technology
[0002] In conventional synthetic aperture radar (SAR) jamming techniques, after the jammed radar RF signal undergoes down-conversion and analog-to-digital conversion, the original sampled data stream is mostly transmitted to general-purpose processing devices such as DSPs and ARMs via a general-purpose parallel interface. The extraction of pulse descriptor parameters such as pulse arrival time, pulse width, pulse repetition interval, and carrier frequency is completed by the back-end software program of the general-purpose processor. The baseband waveform reconstruction, digital up-conversion, and pre-distortion processing of the jamming signal are executed independently in different hardware modules or devices. Pre-distortion processing is mostly implemented at the RF transmitter using analog circuitry.
[0003] The data transmission rate of the general interface has a bottleneck, and the extraction of pulse descriptors at the software level has a timing lag, which cannot match the real-time processing rhythm of high-speed SAR radar signals. Signal interaction between different modules will generate additional delays. The separate execution of interference waveform reconstruction and frequency conversion and predistortion stages can easily cause signal phase shift. The processing accuracy of analog predistortion has inherent limitations. The coherence between the interference signal and the interfered SAR radar signal is difficult to guarantee, and the output stability of the intermediate frequency digital signal is insufficient.
[0004] The raw sampled data stream cannot be directly transmitted to the programmable logic section through the high-speed serial interface and the pulse descriptor can be extracted in real time within it. The coherent interference baseband waveform reconstruction, digital up-conversion and digital predistortion processing cannot be completed synchronously within the same programmable logic section. The existing separation of transmission and processing architecture cannot meet the execution requirements of coherent interference for high-speed SAR radar. Summary of the Invention
[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and propose a SAR radar jamming method based on high-speed data transmission.
[0006] To achieve the above objectives, the present invention employs the following technical solution: a SAR radar jamming method based on high-speed data transmission, comprising:
[0007] The radio frequency signal transmitted by the interfered synthetic aperture radar is received, and the radio frequency signal is down-converted and analog-to-digital converted using a radio frequency receiving front-end to obtain the original sampled data stream;
[0008] The original sampled data stream is transmitted to the programmable logic section via a high-speed serial interface. In the programmable logic section, the original sampled data stream is subjected to digital signal processing to extract pulse descriptors. The pulse descriptors include pulse arrival time, pulse width, pulse repetition interval and carrier frequency parameters.
[0009] Based on the extracted pulse descriptor, the baseband waveform of the interference signal, which is coherent with the interfered synthetic aperture radar signal, is reconstructed in real time in the programmable logic section.
[0010] In the programmable logic section, the reconstructed baseband waveform of the interference signal is digitally up-converted and digitally predistorted to generate the target interference intermediate frequency digital signal.
[0011] The target interference intermediate frequency digital signal is transmitted to the radio frequency transmitting front end through a high-speed serial interface. The digital-to-analog conversion and up-conversion are completed in the radio frequency transmitting front end to generate and radiate the target interference radio frequency signal into space.
[0012] As a further aspect of the present invention, digital signal processing is performed on the original sampled data stream in the programmable logic section to extract pulse descriptors, including:
[0013] The original sampled data stream is digitally down-converted and filtered to obtain orthogonal baseband signal data;
[0014] Threshold detection is performed on the orthogonal baseband signal data to identify the start and end times of each pulse, and the arrival time and pulse width of the pulse are calculated.
[0015] Statistical analysis is performed on the arrival times of multiple consecutive pulses to calculate the time difference sequence between adjacent pulses, and a stable time interval value is extracted from the time difference sequence as the pulse repetition interval.
[0016] Perform spectral analysis on the orthogonal baseband signal data corresponding to each identified pulse, search for the frequency point corresponding to the spectral peak, and confirm the frequency point as the carrier frequency parameter;
[0017] The pulse arrival time, pulse width, pulse repetition interval, and carrier frequency parameters obtained from each identification calculation are encapsulated into a complete pulse descriptor and stored in the first-in-first-out queue of the programmable logic section.
[0018] As a further aspect of the present invention, the step of reconstructing, in real time, the baseband waveform of the interference signal, which is coherent with the interfered synthetic aperture radar signal, in the programmable logic section based on the extracted pulse descriptor includes:
[0019] Read the latest pulse description word from the first-in-first-out queue;
[0020] A local carrier digital oscillation signal is generated based on the carrier frequency parameter in the pulse descriptor;
[0021] Based on the pulse width in the pulse descriptor, a pulse-gated signal with the same time width is generated;
[0022] The local carrier digital oscillation signal is multiplied by the pulse gating signal to generate an unmodulated coherent pulse signal;
[0023] The system receives modulation parameter instructions from the processing system and applies amplitude modulation, phase modulation, or frequency modulation to the unmodulated coherent pulse signal according to the modulation parameter instructions to form a modulated coherent pulse sequence.
[0024] The modulated coherent pulse sequence is repeatedly generated with the pulse repetition interval in the pulse descriptor as the period, thus forming a continuous baseband waveform of the interference signal.
[0025] As a further aspect of the present invention, in the programmable logic section, the reconstructed baseband waveform of the interference signal is subjected to digital up-conversion and digital predistortion processing to generate a target interference intermediate frequency digital signal, including:
[0026] Set a fixed digital intermediate frequency (IF) to generate a local IF digital carrier signal;
[0027] The baseband waveform of the interference signal is digitally mixed with the local intermediate frequency digital carrier signal to shift the spectrum of the baseband waveform of the interference signal to a frequency band centered on the digital intermediate frequency.
[0028] Interpolation filtering is performed on the digital samples of the signal after mixing to increase the sampling rate to the preset RF output sampling rate;
[0029] By looking up a pre-generated RF channel distortion compensation table, the amplitude and phase of each sample point of the signal after the sampling rate is increased are reversed to perform the digital predistortion processing, and the predistorted digital signal is obtained.
[0030] Peak clipping and digital filtering are performed on the pre-distorted digital signal to finally generate the target interference intermediate frequency digital signal that meets the dynamic range requirements of the RF front-end input.
[0031] As a further aspect of the present invention, it also includes the step of running an interference strategy scheduling algorithm in the processing system portion:
[0032] In the embedded operating system running in the processing system section, a dynamically configurable jamming strategy library is maintained, which contains a variety of jamming styles and their corresponding modulation parameter sets.
[0033] Receive threat target indications and jamming pattern selection instructions from the external control interface;
[0034] Based on the threat target indication, the set of pulse descriptors matching the threat target is queried and filtered from the first-in-first-out queue;
[0035] According to the interference pattern selection instruction, an interference pattern is selected from the interference strategy library, and the modulation parameter set corresponding to the interference pattern is obtained;
[0036] The set of modulation parameters corresponding to the selected interference pattern is used as the modulation parameter instruction and sent to the programmable logic section to control the generation of the baseband waveform of the interference signal.
[0037] As a further aspect of the present invention, it also includes the step of using a memory to implement the pre-storage and dynamic loading of interference waveforms in the programmable logic section:
[0038] The solid-state drive connected to the programmable logic section pre-stores various complex-modulated long-time baseband interference waveform data.
[0039] When the modulation parameter instruction issued by the processing system indicates that a pre-stored waveform needs to be loaded, the programmable logic unit initiates a direct memory access read operation on the solid-state drive through the hard core controller.
[0040] Read pre-stored waveform data of a specified length from a specified address of the solid-state drive and load it into the memory inside the programmable logic section;
[0041] During the interference signal generation process, the pre-stored waveform data is read cyclically from the memory inside the programmable logic section to replace the real-time generated baseband waveform of the interference signal;
[0042] The pre-stored waveform data, which is read in a loop, is combined with real-time pulse synchronization information so that the pre-stored waveform data is output within the correct pulse period.
[0043] As a further aspect of the present invention, it also includes, in the programmable logic section, a time synchronization control step for the transmission of interference signals and the sampling of received signals is implemented:
[0044] A high-precision timer / counter is deployed in the programmable logic section;
[0045] Using the pulse arrival time extracted from the received raw sampled data stream, the initial phase of the high-precision timer counter is calibrated to keep it synchronized with the pulse repetition period of the interfered synthetic aperture radar.
[0046] Using the value of the high-precision timer / counter as a time reference, the time for the target interference intermediate frequency digital signal to be transmitted to the radio frequency transmitting front end is controlled, so that the radiated target interference radio frequency signal and the radar echo signal of the expected interference have a set delay or lead relationship in the time domain.
[0047] In the programmable logic section, the arrival time of a newly received pulse is continuously monitored and compared with the predicted value of the high-precision timer / counter;
[0048] When the comparison error exceeds the set threshold, the counting frequency of the high-precision timer / counter is dynamically adjusted or a phase jump is performed to maintain long-term stable synchronization with the interfered synthetic aperture radar.
[0049] As a further aspect of the present invention, the processing system section also includes a step of evaluating interference effects and self-adjusting the strategy:
[0050] In the processing system section, interference effect evaluation data fed back from external electromagnetic environment monitoring equipment is received via a high-speed network interface;
[0051] The interference effect evaluation data is analyzed to extract evaluation indicators that characterize the quality of the interference signal and the effectiveness of the interference.
[0052] The evaluation index is compared with a preset interference effectiveness threshold to determine whether the current interference strategy is effective.
[0053] If the current interference strategy is determined to be invalid, the processing system will autonomously select a backup interference style that is different from the current interference style from the interference strategy library.
[0054] The set of modulation parameters corresponding to the selected backup interference pattern is updated to the new modulation parameter instruction, which is then sent to the programmable logic section to adjust the radiated interference signal.
[0055] As a further aspect of the present invention, it also includes the step of implementing time-division multiplexing interference on multiple concurrent threat targets in the programmable logic section:
[0056] In the programmable logic section, multiple independent signal processing channels and waveform generation channels are maintained in parallel;
[0057] Each of the signal processing channels independently processes radio frequency signals from different threat targets and extracts their respective corresponding pulse descriptors;
[0058] The processing system allocates different interference time slices to each threat target based on threat priority.
[0059] In the programmable logic section, according to the time slice allocated by the processing system section, the corresponding waveform generation channel is controlled to be activated within the specified time slice to generate the target interference intermediate frequency digital signal for a specific threat target;
[0060] A high-speed multiplexer switch is used to multiplex the multiple target interference intermediate frequency digital signals generated in different time slots into a single signal, which is then transmitted to the radio frequency transmitting front end for radiation.
[0061] As a further aspect of the present invention, the step of interpolating and filtering the digital samples of the signal after mixing to increase the sampling rate to a preset radio frequency output sampling rate includes:
[0062] Determine the integer multiple interpolation ratio between the initial sampling rate and the preset RF output sampling rate;
[0063] Between every two adjacent digital samples of the signal after the mixing operation, zero-value samples are inserted in an integer multiple of the interpolation ratio minus one, forming a zero-value-filled sequence.
[0064] Based on the preset RF output sampling rate, a low-pass filter with linear phase characteristics is designed, wherein the cutoff frequency of the low-pass filter is less than or equal to half of the initial sampling rate.
[0065] The zero-padded sequence is convolved through the low-pass filter to suppress the high-frequency mirror spectrum introduced by the zero-value insertion;
[0066] Gain compensation is performed on the output sequence after convolution to ensure that the signal power is not attenuated due to the interpolation process;
[0067] From the output sequence after gain compensation, the portion containing valid data is extracted to obtain the digital signal sequence after interpolation and filtering;
[0068] The sampling rate of the interpolated and filtered digital signal sequence is the preset radio frequency output sampling rate.
[0069] Compared with the prior art, the advantages and positive effects of the present invention are as follows:
[0070] The raw sampled data stream is directly transmitted to the programmable logic unit (PLU) via a high-speed serial interface. The extraction operations of pulse arrival time, pulse width, pulse repetition interval, and carrier frequency parameters are executed in real time within the PLU. The transmission link length of the sampled data stream is reduced, the latency during data transmission is kept at a low level, the timing lag caused by back-end software processing is avoided, the pulse descriptor extraction response speed is synchronized with the reception rhythm of SAR radar RF signals, the real-time performance and timeliness of parameter extraction meet the requirements of high-speed signal processing, and the stability of data transmission breaks through the limitation of the general interface rate bottleneck, adapting to the sampling data transmission requirements of high-speed SAR radar signals.
[0071] Within the same programmable logic unit, the baseband waveform of the interference signal, which is coherent with the jammed SAR radar signal, is reconstructed in real time based on the pulse descriptor. Simultaneously, digital up-conversion and digital predistortion processing are performed on the baseband waveform to generate the target interference intermediate frequency digital signal. The data interaction links between different devices or modules are reduced, and the phase shift and signal loss during waveform processing are at a low level. The digital predistortion processing directly acts on the baseband waveform level, and the processing accuracy is more precise than the analog processing method at the radio frequency end. The reconstruction, frequency conversion, and predistortion processing of the coherent interference baseband waveform form a continuous hardware execution process. The phase consistency and signal purity of the intermediate frequency output of the interference signal are maintained, and the generation accuracy and real-time performance of the coherent interference signal match the signal characteristics of the SAR radar. Attached Figure Description
[0072] Figure 1 This is a flowchart of the SAR radar jamming method based on high-speed data transmission described in this invention;
[0073] Figure 2 A flowchart for reconstructing the baseband waveform of an interference signal;
[0074] Figure 3 A timing monitoring diagram of SAR radar pulse descriptor parameters (carrier frequency timing changes);
[0075] Figure 4 The curves show the relationship between pulse synchronization error and dynamic frequency adjustment.
[0076] Figure 5 Box plots showing the interference-to-signal ratio distribution under different SAR radar interference patterns. Detailed Implementation
[0077] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0078] In the description of this invention, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, in the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.
[0079] See Figure 1 This invention provides a synthetic aperture radar jamming method based on high-speed data transmission, the specific method including:
[0080] This method involves a complete implementation process for an electronic jamming device, which begins with the reception of a threat radar signal and ends with the radiation of a jamming signal. The radio frequency (RF) signal emitted by the targeted synthetic aperture radar (SAR) is first received by the system's RF receiving front-end. The RF receiving front-end performs down-conversion processing on the signal, converting it from a high-frequency band to an intermediate frequency (IF) or baseband, and then performs analog-to-digital conversion, generating a stream of raw sampled data. This data stream is transmitted at high speed through a high-speed serial interface to the system's programmable logic (PLL) section, where core signal processing is performed. In the PPL section, digital signal processing algorithms are executed on the raw sampled data stream to extract pulse descriptors characterizing the radar signal. These descriptors contain key parameters such as pulse arrival time, pulse width, pulse repetition interval, and carrier frequency. Subsequently, based on the extracted pulse descriptors, the PPL section reconstructs in real-time the baseband waveform of the jammed SAR signal, maintaining coherence with the SAR signal in terms of carrier frequency, pulse width, and repetition rate. The reconstructed baseband waveform of the interference signal then undergoes further digital processing in the programmable logic section, including digital up-conversion to shift its spectrum to the intermediate frequency band, and digital pre-distortion processing to compensate for the nonlinear characteristics of subsequent radio frequency channels, ultimately generating the target interference intermediate frequency digital signal. This target interference intermediate frequency digital signal is then transmitted to the system's radio frequency transmission front-end via a high-speed serial interface. The radio frequency transmission front-end performs digital-to-analog conversion on this digital signal, restoring it to an analog signal, and up-converts it to the radio frequency band, ultimately generating and radiating a target interference radio frequency signal with the desired interference effect into space.
[0081] In one embodiment of the present invention, the received raw sampled data stream undergoes digital signal processing in the programmable logic section to extract pulse descriptors. This process first performs digital down-conversion and filtering on the raw sampled data stream to generate orthogonal baseband signal data. Threshold detection is performed on the obtained orthogonal baseband signal data to identify the start and end times of each radar pulse, and the pulse arrival time and pulse width are calculated accordingly. Statistical analysis is performed on the arrival times of multiple consecutive identified pulses to calculate the time difference sequence between adjacent pulses, and a stable, recurring time interval value is extracted from this time difference sequence; this value is identified as the pulse repetition interval. For each identified pulse, spectral analysis is performed on its corresponding orthogonal baseband signal data to search for the frequency point corresponding to the spectral peak, and this frequency point is recorded as the carrier frequency parameter of the pulse. The pulse arrival time, pulse width, pulse repetition interval, and carrier frequency parameter obtained from each identification and calculation are integrated and encapsulated into a complete set of pulse descriptors, and this set of pulse descriptors is stored in a first-in-first-out queue configured within the programmable logic section.
[0082] When reconstructing the baseband waveform of the coherent interference signal in real time based on the extracted pulse descriptor, refer to... Figure 2 The system reads the latest pulse descriptor from the aforementioned first-in-first-out queue. Based on the carrier frequency parameters contained in the pulse descriptor, a local carrier digital oscillator signal is generated in the programmable logic section. Simultaneously, based on the pulse width parameters in the pulse descriptor, a pulse gating signal with the same time width is generated. The local carrier digital oscillator signal and the pulse gating signal are digitally multiplied to generate an unmodulated coherent pulse signal. The programmable logic section receives modulation parameter instructions from the processing system section and, according to the instructions, applies specified amplitude modulation, phase modulation, or frequency modulation operations to the unmodulated coherent pulse signal to form a modulated coherent pulse sequence. Finally, the modulated coherent pulse sequence is repeatedly generated cyclically with the pulse repetition interval recorded in the pulse descriptor as the period, thereby forming a continuous interference signal baseband waveform.
[0083] In practical implementation, the programmable logic unit performs digital down-conversion and filtering on the original sampled data stream. For example, the received RF signal is down-converted to generate an intermediate frequency (IF) signal with a center frequency of fIF equal to 70MHz. The original sampled data stream, obtained by analog-to-digital conversion at a sampling rate of fS equal to 250MSPS, is then digitally down-converted to zero IF and passed through a low-pass filter with a cutoff frequency of fc equal to 20MHz, thereby obtaining orthogonal baseband signal data. The orthogonal baseband signal data is then sent to the threshold detection module. The threshold detection module uses a fixed threshold and leading-edge detection algorithm. When the envelope amplitude of the orthogonal baseband signal data exceeds a preset voltage threshold, it is marked as the pulse start point. When the envelope amplitude falls back below the threshold, it is marked as the pulse end point. After identifying the start and end times of each pulse, the pulse arrival time and pulse width parameters are calculated. In specific implementations, the programmable logic unit (PLU) performs statistical analysis on the arrival times of multiple consecutive pulses, calculates the time difference sequence between adjacent pulses, and extracts stable time interval values from the time difference sequence as the pulse repetition interval. This extraction process involves histogram statistics on a set of time difference values, identifying the time interval with the highest frequency as the pulse repetition interval. In some embodiments, the PLU performs spectral analysis on the orthogonal baseband signal data corresponding to each identified pulse, searching for the frequency point corresponding to the spectral peak. This frequency point is identified as the carrier frequency parameter. The spectral analysis is implemented using a Fast Fourier Transform (FFT), searching for the frequency value corresponding to the maximum spectral line within a Banal analysis bandwidth of 100MHz. In specific implementations, the pulse arrival time, pulse width, pulse repetition interval, and carrier frequency parameter calculated for each identification are encapsulated into a complete pulse descriptor and stored in a first-in-first-out (FIFO) queue built internally by the PLU. The FIFO queue is configured with a depth of DFIFO equal to 64 to cache consecutive pulse descriptors.
[0084] The baseband waveform of the interference signal is reconstructed in real time in the programmable logic section based on the extracted pulse descriptor. In specific implementations, the waveform generation module reads the latest pulse descriptor from the first-in-first-out queue. The waveform generation module generates a local carrier digital oscillation signal based on the carrier frequency parameter in the pulse descriptor. The digital oscillation signal is generated by a numerically controlled oscillator, and its frequency control word is obtained by dividing the carrier frequency parameter by the system clock frequency fclk. The waveform generation module generates a pulse-gated signal with the same time width as the pulse width in the pulse descriptor. The pulse-gated signal is a rectangular wave that is high for the duration of the pulse width and low for the rest of the time. The waveform generation module multiplies the local carrier digital oscillation signal with the pulse-gated signal to generate an unmodulated coherent pulse signal. In some embodiments, the waveform generation module receives modulation parameter instructions from the processing system section and applies amplitude modulation, phase modulation, or frequency modulation to the unmodulated coherent pulse signal according to the modulation parameter instructions to form a modulated coherent pulse sequence. For example, if the modulation parameter instructions specify a linear frequency modulation style, then a modulation with a frequency that changes linearly with time is applied to the coherent pulse signal. Optionally, the waveform generation module repeatedly generates a modulated coherent pulse sequence with the pulse repetition interval in the pulse descriptor as the period, forming a continuous baseband waveform of the interference signal. This repetition is triggered by a timer with a period equal to the pulse repetition interval. The simplified model formula for pulse signal generation is as follows:
[0085] ,in: It is an unmodulated coherent pulse signal. It is the signal function after modulation. The pulse width is The rectangular window function, Represents a time variable.
[0086] In one embodiment of the present invention, the reconstructed interference signal baseband waveform is digitally up-converted and digitally predistorted in the programmable logic section to generate a target interference intermediate frequency (IF) digital signal. This process pre-sets a fixed IF frequency and generates a local IF digital carrier signal. The interference signal baseband waveform and the local IF digital carrier signal are digitally mixed to shift the spectrum of the interference signal baseband waveform to a frequency band centered on the IF frequency. Subsequently, interpolation filtering is performed on the digital samples of the mixed signal to increase its sampling rate to a preset RF output sampling rate. The specific steps of this interpolation filtering include: determining an integer multiple interpolation ratio between the initial sampling rate and the preset RF output sampling rate; inserting zero-value samples equal to the integer multiple interpolation ratio minus one between every two adjacent digital samples of the signal after mixing, forming a new zero-filled sequence; designing a low-pass filter with linear phase characteristics based on the preset RF output sampling rate, the cutoff frequency of which is less than or equal to half of the initial sampling rate; performing convolution operation on the zero-filled sequence through this low-pass filter to suppress the high-frequency image spectrum introduced by zero-value insertion; applying gain compensation to the output sequence after convolution operation to ensure that the signal power does not attenuate during the interpolation process; extracting the portion containing valid data from the gain-compensated output sequence to finally obtain the interpolated filtered digital signal sequence, the sampling rate of which is the preset RF output sampling rate. After the sampling rate is increased, the amplitude and phase of each digital sample of the signal after the sampling rate increase are inversely compensated by looking up the RF channel distortion compensation table pre-generated and stored in the programmable logic section memory. This achieves digital predistortion processing, resulting in a predistorted digital signal. Finally, peak clipping and digital filtering operations are performed on the predistorted digital signal to generate a target interference intermediate frequency digital signal that meets the dynamic range requirements of the RF front-end input.
[0087] In practical implementation, a digital up-conversion and digital predistortion processing step in a synthetic aperture radar jamming method based on high-speed data transmission sets a fixed digital intermediate frequency. Digital intermediate frequency The value is 70MHz, generating a local intermediate frequency digital carrier signal. Local intermediate frequency digital carrier signal Generated by a digitally controlled oscillator, its real part is a cosine function, its imaginary part is a sine function, and the function phase is determined by the digital intermediate frequency. With system sampling clock period Decision. The digital upconversion module will convert the baseband waveform of the interference signal. With local intermediate frequency digital carrier signal Digital mixing is performed, which is achieved through complex multiplication, thereby converting the baseband waveform of the interference signal. The spectrum was shifted from baseband to digital intermediate frequency. The frequency band centered on this is then used. Next, interpolation filtering is applied to the digital samples of the mixed signal to increase the sampling rate to a preset RF output sampling rate. The value is 1.2 GSPS. In practice, interpolation filtering is used to determine the initial sampling rate. With the preset RF output sampling rate Integer multiples of interpolation ratio Integer multiple interpolation ratio Through formula Calculations show that when the initial sampling rate... 300MSPS and RF output sampling rate For an integer multiple of 1.2 GSPS, the interpolation ratio Equals 4. In interpolation filtering, the number of samples inserted between every two adjacent digital samples of the signal after mixing is an integer multiple of the interpolation ratio. The zero-valued samples are reduced by one to form a new sequence with zero-value filling. In some embodiments, the interpolation filtering process is based on a preset RF output sampling rate. Design a finite impulse response low-pass filter with linear phase characteristics. The cutoff frequency of the low-pass filter is... Less than or equal to the initial sampling rate Half of the filter tap coefficients are calculated using the Parks-McClellan algorithm. Interpolation filtering processes the zero-padded sequence. Convolution is performed using this low-pass filter to suppress high-frequency image spectra introduced by zero-value interpolation. Interpolation filtering applies gain compensation to the output sequence after convolution, with the gain compensation coefficients set to integer multiples of the interpolation ratio. This ensures that the signal power does not attenuate during interpolation. The interpolation filtering process extracts the portion containing valid data from the gain-compensated output sequence to obtain the interpolated and filtered digital signal sequence. The digital signal sequence after interpolation filtering The sampling rate is the preset RF output sampling rate. .
[0088] After the sampling rate increase is completed, the digital predistortion module searches the RF channel distortion compensation table pre-generated and stored in the programmable logic section memory to adjust the signal after the sampling rate increase. Each digital sample undergoes inverse amplitude and phase compensation calculations to achieve digital predistortion processing. The RF channel distortion compensation table is generated during system initialization after measuring the amplitude and phase nonlinear characteristics of the channel using an external calibration source and power detector. The table index is a two-dimensional function of the instantaneous amplitude and frequency of the input signal. The compensation relationship formula for a single sample in digital predistortion processing is as follows:
[0089] ,in: It is the m-th complex sample point output after predistortion compensation. It is the m-th input complex sample to be compensated. This is an amplitude compensation lookup table function, whose output is dimensionless real-valued amplitude compensation coefficients. Input samples instantaneous amplitude, It is a lookup table index generated based on sample frequency information. This is a phase compensation lookup table function that outputs the phase compensation value in radians. It is the imaginary unit. The digital signal after predistortion is obtained. Then, the peak limiting module applies the pre-distorted digital signal. Peak clipping and digital filtering operations are performed to generate a target interference intermediate frequency digital signal that meets the dynamic range requirements of the RF front-end input. In some embodiments, the peak clipping operation modifies the pre-distorted digital signal... The modulus of a complex number is limited to a preset maximum value. The modulus of samples exceeding the limit is clamped to... The phase remains unchanged. The digital filtering operation employs a root-raised cosine filter with a roll-off factor of 0.25 to constrain the bandwidth of the final output target interference intermediate frequency digital signal and avoid out-of-band spectrum leakage. It can be understood that digital up-conversion, interpolation filtering, digital predistortion, and subsequent filtering operations are all continuously completed in the pipeline of the programmable logic section to ensure real-time processing.
[0090] In one embodiment of the present invention, an interference strategy scheduling algorithm is run in the processing system section. An embedded operating system running in the processing system section maintains a dynamically configurable interference strategy library, which contains various preset interference styles and a set of modulation parameters corresponding to each interference style. The processing system section receives threat target indications and interference style selection instructions from an external control interface. Based on the received threat target indications, the processing system section queries and filters a set of pulse descriptors matching the signal characteristics of the specified threat target from the first-in-first-out queue of the programmable logic section. Simultaneously, based on the received interference style selection instructions, it selects an interference style from the interference strategy library and obtains the set of modulation parameters corresponding to the selected interference style. Then, the processing system section sends the set of modulation parameters corresponding to the selected interference style as a modulation parameter instruction to the programmable logic section to control the generation of the baseband waveform of the interference signal.
[0091] In the programmable logic unit (PLU), memory is used to pre-store and dynamically load interference waveforms. A solid-state drive (SSD) connected to the PLU pre-stores various complex modulation long-duration baseband interference waveforms. When the processing system issues a modulation parameter command indicating the need to load the pre-stored waveform, the PLU initiates a direct memory access (DMI) read operation on the SSD via its integrated hard-core controller. A specified length of pre-stored waveform data is read from a specified logical address on the SSD and loaded into the PLU's internal high-speed memory. During interference signal generation, this pre-stored waveform data can be cyclically read from the internal memory to replace the real-time generated interference signal baseband waveform. At output, the cyclically read pre-stored waveform data is combined with pulse synchronization information extracted in real-time from the radar signal to ensure that the pre-stored waveform data is output within the correct radar pulse period.
[0092] In practical implementation, the embedded operating system of the processing system maintains a dynamically configurable jamming strategy library. This library is stored in the form of a structured database or configuration file, defining various jamming styles and their corresponding modulation parameter sets. Table 1 lists the mapping relationships between some jamming styles and their key modulation parameters in the jamming strategy library. The processing system receives threat target indications and jamming style selection commands from an external control interface via Ethernet or PCIe. Based on the received threat target indications, the processing system queries and filters the set of pulse descriptors matching the signal characteristics of the specified threat target from the first-in-first-out queue of the programmable logic unit. This filtering process is achieved by comparing the radar characteristic parameter range given by the external command with each pulse descriptor in the first-in-first-out queue. Based on the received jamming style selection command, the processing system selects a jamming style from the jamming strategy library and obtains the modulation parameter set corresponding to the selected jamming style. Subsequently, the processing system will select the set of modulation parameters corresponding to the interference pattern as the modulation parameter instruction and send it to the programmable logic section to control the generation of the baseband waveform of the interference signal in the programmable logic section. The modulation parameter instruction is transmitted in a specific data frame format through shared memory or high-speed serial bus.
[0093] In the programmable logic unit (PLU), memory is used to pre-store and dynamically load interference waveforms. In specific implementation, a solid-state drive (SSD) connected to the PLU pre-stores various complex modulation long-duration baseband interference waveforms. The waveform data is stored in a complex number format, with each waveform having a corresponding identifier and waveform length information. When the processing system issues a modulation parameter command indicating the need to load the pre-stored waveform, the PLU initiates a direct memory access (DMI) read operation on the SSD through its integrated hard-core controller. A specified length of pre-stored waveform data is read from a specified logical address on the SSD and loaded into the high-speed memory within the PLU. This high-speed memory can be a double data rate synchronous dynamic random access memory (DRAM). During interference signal generation, the waveform generation module cyclically reads the pre-stored waveform data from the high-speed memory within the PLU to replace the real-time generated interference signal baseband waveform. The index logic formula for memory waveform reading is:
[0094] ,in: It is the m-th waveform sample point in the output. It is the k-th waveform sample point stored in the internal high-speed memory. It is the total number of samples of the pre-stored waveform data. This indicates a modulo operation. During output, the waveform generation module will cyclically read the pre-stored waveform data. Combined with pulse synchronization information extracted in real time from radar signals, including pulse arrival time and pulse width, this ensures that pre-stored waveform data is used effectively. It can be output within the correct radar pulse period. See Table 1.
[0095] Table 1: Interference Strategy Library
[0096] ,
[0097] See Figure 3 In the timing monitoring of SAR radar pulse descriptor parameters, the timing variation analysis of carrier frequency parameters is the core basis for realizing radar signal feature extraction and coherent interference. Specifically, using the time axis as a reference, the carrier frequency of the radar pulse sequence is sampled and recorded pulse by pulse, forming the timing variation curve shown in the figure. This curve intuitively reflects the dynamic fluctuation characteristics of the carrier frequency of the jammed SAR radar transmitted signal within the 9.5GHz~10.45GHz range, and can be used for pulse descriptor encapsulation and subsequent coherent reconstruction of the interference signal. In the pulse descriptor extraction process, this timing data corresponds to the peak frequency detection result of each pulse's spectrum: by performing spectrum analysis on the orthogonal baseband signal data, the frequency point corresponding to the main lobe peak of the spectrum is located, and it is encapsulated as a carrier frequency parameter and stored in a first-in-first-out queue. In the interference signal reconstruction stage, a local carrier digital oscillation signal is generated based on this timing data to ensure that the interference signal and the jammed radar signal maintain strict phase coherence. During parameter configuration, the sampling accuracy of the carrier frequency is set to the order of 1MHz to match the frequency resolution requirements of the SAR radar system, while ensuring the real-time performance and stability of the timing monitoring.
[0098] In one embodiment of the present invention, time synchronization control of the transmission of the jamming signal and the sampling of the received signal is implemented in the programmable logic section. A high-precision timer / counter is deployed in the logic resources of the programmable logic section. Using the pulse arrival time information extracted from the received raw sampled data stream, the initial phase of the high-precision timer / counter is calibrated to keep it synchronized with the pulse repetition period of the currently jammed synthetic aperture radar. Using the count value of the high-precision timer / counter as a time reference, the transmission time of the generated target jamming intermediate frequency digital signal to the radio frequency transmission front end is precisely controlled, so that the final radiated target jamming radio frequency signal has a set delay or lead relationship with the radar echo signal to be jammed in the time domain. During the jamming process, the programmable logic section continuously monitors the arrival time of newly received radar pulses and compares them with the predicted value of the high-precision timer / counter in real time. When the error obtained from the comparison exceeds a set threshold, the programmable logic section dynamically adjusts the counting frequency of the high-precision timer / counter or performs a phase jump operation to maintain stable synchronization with the jammed synthetic aperture radar for a long time.
[0099] The processing system implements interference effect assessment and strategy self-adjustment. It receives interference effect assessment data from external electromagnetic environment monitoring equipment via its high-speed network interface. The processing system parses this data, extracting key evaluation indicators characterizing the quality of the current radiated interference signal and its effectiveness in jamming the target radar. These indicators are then compared with preset interference effectiveness thresholds to determine the effectiveness of the currently implemented interference strategy. If the determination indicates that the current interference strategy is ineffective, the processing system autonomously selects a backup interference pattern from the interference strategy library. Next, it updates the modulation parameter set corresponding to the selected backup interference pattern with new modulation parameter instructions and immediately sends them to the programmable logic unit, thereby adjusting the pattern of the radiated interference signal.
[0100] In practical implementation, a high-precision timer / counter is deployed in the logic resources of the programmable logic section. The clock input of the high-precision timer / counter comes from the system's high-stability crystal oscillator. Using the pulse arrival time information extracted from the received raw sampled data stream, the initial phase of the high-precision timer / counter is calibrated to synchronize it with the pulse repetition period of the currently jammed synthetic aperture radar. The calibration process sets the count value of the high-precision timer / counter to the system clock count value corresponding to the latest pulse arrival time. Using the count value of the high-precision timer / counter as a time reference, the transmission time of the generated target jamming intermediate frequency digital signal to the RF transmitting front end is precisely controlled. This ensures that the final radiated target jamming RF signal has a predetermined delay or lead relationship with the radar echo signal to be jammed in the time domain. A trigger signal is generated by a high-precision timer / counter to control the transmission timing of the jamming signal. During jamming, the signal processing channel of the programmable logic unit continuously monitors the arrival time of newly received radar pulses. and the predicted value of the high-precision timer / counter Real-time comparison is performed. When the error obtained from the comparison exceeds a set threshold, the programmable logic section dynamically adjusts the counting frequency of the high-precision timer / counter or performs a phase transition operation to maintain stable synchronization with the interfered synthetic aperture radar for a long period of time. The frequency adjustment calculation formula for adjacent period measurements is as follows: ,in: This is the adjusted counting frequency. It is the nominal counting frequency. It is the predicted arrival time of the i-th pulse. It is the actual measurement time when the i-th pulse arrives, and the subscript i indicates the pulse number.
[0101] The processing system implements interference effect evaluation and strategy self-adjustment. It receives interference effect evaluation data from external electromagnetic environment monitoring equipment via its high-speed network interface. The processing system analyzes this data, extracting key evaluation indicators characterizing the quality of the current radiated interference signal and its effectiveness in jamming the target radar. These key indicators include the interference-to-signal ratio (CNR), the success rate of decoy spoofing, and the level of radar image quality degradation. The processing system then compares these key evaluation indicators with preset interference effectiveness thresholds to determine the effectiveness of the currently implemented interference strategy. These thresholds are stored in a lookup table. Table 2 defines the thresholds for key evaluation indicators under several common interference patterns. If the determination result indicates that the current interference strategy is ineffective, the processing system autonomously selects a backup interference pattern from the interference strategy library. The selection process employs polling or a pre-defined priority list. Next, the processing system updates the modulation parameter set corresponding to the selected backup interference pattern with new modulation parameter instructions and immediately sends this information to the programmable logic unit via the inter-system communication link, thereby adjusting the pattern of the radiated interference signal. In practice, the processing system continuously receives evaluation data and performs analysis and judgment, forming a closed-loop interference strategy control loop. See Table 2.
[0102] Table 2: Example Table of Interference Effectiveness Thresholds
[0103] ,
[0104] See Figure 4In the process of pulse synchronization error and dynamic frequency adjustment, the evolution of synchronization error with pulse number intuitively reflects the closed-loop regulation effect of time synchronization control. The bar sequence in the figure represents the synchronization error (unit: ns), and the dashed lines represent the upper and lower thresholds of the error, respectively. In the pulse number range of 0–15, the synchronization error remains in the positive range and the peak value is close to 6ns, which does not exceed the threshold range, indicating that the counter phase has completed the initial calibration in the initial synchronization stage and established a basic synchronization relationship with the radar pulse repetition period. In the pulse number range of 16–20, the synchronization error turns from positive to negative and gradually increases, indicating that there is a systematic deviation between the radar pulse arrival time and the counter prediction value, triggering the frequency adjustment mechanism. After pulse number 20, the synchronization error continues to accumulate in the negative direction and gradually exceeds the lower threshold, reflecting the execution process of dynamic frequency adjustment and phase jump operation. The counter continuously corrects the counting frequency, so that the synchronization error gradually converges to a more stable range, and finally controls the error within the range of -17ns to 0ns near pulse number 50, achieving long-term stable synchronization with the pulse repetition period of the jammed SAR radar. The figure presents the closed-loop control process of initial synchronization—error accumulation—dynamic correction—stable convergence, which verifies the effectiveness of the high-precision timer / counter in pulse synchronization and dynamic frequency adjustment, and provides a quantitative basis for the accurate time-domain alignment of interference signals and radar echoes.
[0105] In one embodiment of the present invention, time-division multiplexing interference is implemented against multiple concurrent threat targets in the programmable logic section. Multiple independent signal processing channels and waveform generation channels are maintained in parallel within the logic resources of the programmable logic section. Each signal processing channel independently processes radio frequency signal sampling streams from different threat targets and extracts their respective pulse descriptors. The processing system allocates different interference time slots for each target based on its priority. In the programmable logic section, according to the time slot scheduling information allocated by the processing system, the corresponding waveform generation channel is activated within its designated time slot to generate an interference signal targeting that specific threat target, forming a corresponding target interference intermediate frequency digital signal. Finally, through a high-speed multiplexer, the multiple target interference intermediate frequency digital signals generated by different waveform generation channels within different time slots are multiplexed into a single continuous signal stream according to the time slot sequence and transmitted to the radio frequency transmitting front end for radiation.
[0106] In practical implementation, multiple independent signal processing channels and waveform generation channels are maintained in parallel within the programmable logic unit's logic resources. The number of signal processing channels N and the number of waveform generation channels M can be equal, for example, N=M=4. Each signal processing channel independently processes RF signal sampling streams from different threat targets and extracts their corresponding pulse descriptors. The RF signals received by each signal processing channel come from an independent RF receiving front-end or different digitization channels of a broadband receiving front-end. The processing system allocates different interference time slots to each threat target based on their priority. The priority of the threat targets is specified by an external control interface or automatically determined by the processing system based on radar signal parameters. In the programmable logic unit, based on the time slot scheduling information allocated by the processing system, the corresponding waveform generation channel is activated within its designated time slot to generate an interference signal targeting that specific threat target and form the corresponding target interference intermediate frequency digital signal. The time slot scheduling information is written from the processing system to the programmable logic unit in the form of a control register. The activation time formula for the k-th waveform generation channel is as follows: ,in: It is the start time when the k-th waveform generation channel is activated for the nth time. It is the initial activation offset time of the k-th waveform generation channel within one scheduling frame period. Where n is the period length of the scheduling frame, and n is the frame number. In some embodiments, the activation time slots of each waveform generation channel are non-overlapping within a scheduling frame period. Finally, a high-speed multiplexer switch multiplexes the multiple target interference intermediate frequency digital signals generated by different waveform generation channels in different time slots into a single continuous signal stream according to the time slot sequence, which is then transmitted to the RF transmitting front end for radiation. The switching of the high-speed multiplexer switch is precisely controlled by the time slot scheduling information allocated by the processing system, and its switching time is strictly synchronized with the activation and deactivation times of each waveform generation channel to prevent signal discontinuity or glitches.
[0107] In practical implementation, the length of the interference time slice allocated to each threat target by the processing system is related to the priority of the threat target; higher-priority threat targets are allocated longer or more frequent interference time slices. The time slice scheduling controller in the programmable logic unit sends an enable signal to the corresponding waveform generation channel at the beginning of each time slice based on the scheduling table issued by the processing system, and deactivates the enable signal at the end of the time slice. Upon receiving the enable signal, the waveform generation channel begins generating the target interference intermediate frequency digital signal based on the pulse descriptor and modulation parameter instructions allocated to it. After the enable signal is deactivated, the output of the waveform generation channel is set to zero or enters a low-power state. Multiple target interference intermediate frequency digital signals output from different waveform generation channels are connected to the respective input ports of a high-speed multiplexer. Based on the time slice scheduling information, the high-speed multiplexer connects only the input and output ports corresponding to the currently active waveform generation channel at each moment, thereby achieving time-domain multiplexing of multiple signals and ultimately forming a continuous target interference intermediate frequency digital signal stream that time-divisionally interferes with multiple threat targets.
[0108] See Figure 5In the SAR radar jamming effectiveness evaluation system, the interference-to-signal ratio (dB) is a core performance indicator. Its distribution characteristics are visually presented through box plots to show the differences in the effectiveness of different jamming styles. The figure shows the statistical distribution of the interference-to-signal ratio for four typical jamming styles: noise suppression JS-01, range deception JS-02, false target JS-03, and coherent suppression JS-04. The boxes in the box plot represent the interquartile range (IQR), the inner red line is the median, and the upper and lower bars correspond to the maximum and minimum values of the data (after removing outliers), respectively. Hollow circles represent outliers. Statistically, coherent suppression JS-04 exhibits the highest interference-to-signal ratio level, with a median of approximately 19 dB. Both the box range (16–21 dB) and the overall distribution are significantly higher than other styles, indicating that it has the strongest ability to suppress radar signals and the most stable jamming effectiveness. At the same time, there is a high-value outlier (approximately 27 dB), reflecting the jamming gain under extreme scenarios. The noise suppression JS-01 has a median interference ratio of approximately 13.5 dB, with a box range of 12–15 dB. Its overall performance is second best, with a moderate interference-to-signal ratio (ISR) fluctuation range and no obvious outliers, indicating a relatively balanced interference effect. The range deception JS-02 and false target JS-03 have similar ISR levels, with medians of approximately 7.8 dB and 5.8 dB respectively, and box ranges of 7–9 dB and 5–6.5 dB respectively. Both have low-value outliers, indicating that deception-type interference is weaker than suppression-type interference in improving ISR and is more susceptible to performance fluctuations due to scene factors. Overall, suppression-type interference (coherent suppression, noise suppression) has a significantly better ISR than deception-type interference (range deception, false targets). Among them, coherent suppression JS-04 exhibits the best interference performance and stability and can be considered the preferred interference pattern; while noise suppression JS-01 achieves a good balance between performance and implementation complexity.
[0109] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments that can be applied to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.
Claims
1. A SAR radar jamming method based on high-speed data transmission, characterized in that, The method includes: The radio frequency signal transmitted by the interfered synthetic aperture radar is received, and the radio frequency signal is down-converted and analog-to-digital converted using a radio frequency receiving front-end to obtain the original sampled data stream; The original sampled data stream is transmitted to the programmable logic section via a high-speed serial interface. In the programmable logic section, the original sampled data stream is subjected to digital signal processing to extract pulse descriptors. The pulse descriptors include pulse arrival time, pulse width, pulse repetition interval and carrier frequency parameters. Based on the extracted pulse descriptor, the baseband waveform of the interference signal, which is coherent with the interfered synthetic aperture radar signal, is reconstructed in real time in the programmable logic section. In the programmable logic section, the reconstructed baseband waveform of the interference signal is digitally up-converted and digitally predistorted to generate the target interference intermediate frequency digital signal. The target interference intermediate frequency digital signal is transmitted to the radio frequency transmitting front end through a high-speed serial interface. Digital-to-analog conversion and up-conversion are performed in the radio frequency transmitting front end to generate and radiate the target interference radio frequency signal into space. In the programmable logic section, the time synchronization control steps for interference signal transmission and received signal sampling are implemented: A high-precision timer / counter is deployed in the programmable logic section; Using the pulse arrival time extracted from the received raw sampled data stream, the initial phase of the high-precision timer counter is calibrated to keep it synchronized with the pulse repetition period of the interfered synthetic aperture radar. Using the value of the high-precision timer / counter as a time reference, the time for the target interference intermediate frequency digital signal to be transmitted to the radio frequency transmitting front end is controlled, so that the radiated target interference radio frequency signal and the radar echo signal of the expected interference have a set delay or lead relationship in the time domain. In the programmable logic section, the arrival time of a newly received pulse is continuously monitored and compared with the predicted value of the high-precision timer / counter; When the comparison error exceeds the set threshold, the counting frequency of the high-precision timer / counter is dynamically adjusted or a phase jump is performed to maintain long-term stable synchronization with the interfered synthetic aperture radar.
2. The SAR radar jamming method based on high-speed data transmission according to claim 1, characterized in that, The programmable logic section performs digital signal processing on the raw sampled data stream to extract pulse descriptors, including: The original sampled data stream is digitally down-converted and filtered to obtain orthogonal baseband signal data; Threshold detection is performed on the orthogonal baseband signal data to identify the start and end times of each pulse, and the arrival time and pulse width of the pulse are calculated. Statistical analysis is performed on the arrival times of multiple consecutive pulses to calculate the time difference sequence between adjacent pulses, and a stable time interval value is extracted from the time difference sequence as the pulse repetition interval. Perform spectral analysis on the orthogonal baseband signal data corresponding to each identified pulse, search for the frequency point corresponding to the spectral peak, and confirm the frequency point as the carrier frequency parameter; The pulse arrival time, pulse width, pulse repetition interval, and carrier frequency parameters obtained from each identification calculation are encapsulated into a complete pulse descriptor and stored in the first-in-first-out queue of the programmable logic section.
3. The SAR radar jamming method based on high-speed data transmission according to claim 2, characterized in that, Based on the extracted pulse descriptor, the programmable logic section reconstructs in real time the baseband waveform of the interference signal, which is coherent with the interfered synthetic aperture radar signal, including: Read the latest pulse description word from the first-in-first-out queue; A local carrier digital oscillation signal is generated based on the carrier frequency parameter in the pulse descriptor; Based on the pulse width in the pulse descriptor, a pulse-gated signal with the same time width is generated; The local carrier digital oscillation signal is multiplied by the pulse gating signal to generate an unmodulated coherent pulse signal; The system receives modulation parameter instructions from the processing system and applies amplitude modulation, phase modulation, or frequency modulation to the unmodulated coherent pulse signal according to the modulation parameter instructions to form a modulated coherent pulse sequence. The modulated coherent pulse sequence is repeatedly generated with the pulse repetition interval in the pulse descriptor as the period, thus forming a continuous baseband waveform of the interference signal.
4. The SAR radar jamming method based on high-speed data transmission according to claim 3, characterized in that, In the programmable logic section, the reconstructed baseband waveform of the interference signal undergoes digital up-conversion and digital predistortion processing to generate the target interference intermediate frequency digital signal, including: Set a fixed digital intermediate frequency (IF) to generate a local IF digital carrier signal; The baseband waveform of the interference signal is digitally mixed with the local intermediate frequency digital carrier signal to shift the spectrum of the baseband waveform of the interference signal to a frequency band centered on the digital intermediate frequency. Interpolation filtering is performed on the digital samples of the signal after mixing to increase the sampling rate to the preset RF output sampling rate; By looking up a pre-generated RF channel distortion compensation table, the amplitude and phase of each sample point of the signal after the sampling rate is increased are reversed to perform the digital predistortion processing, and the predistorted digital signal is obtained. Peak clipping and digital filtering are performed on the pre-distorted digital signal to finally generate the target interference intermediate frequency digital signal that meets the dynamic range requirements of the RF front-end input.
5. The SAR radar jamming method based on high-speed data transmission according to claim 4, characterized in that, It also includes the step of running the interference policy scheduling algorithm in the processing system section: In the embedded operating system running in the processing system section, a dynamically configurable jamming strategy library is maintained, which contains a variety of jamming styles and their corresponding modulation parameter sets. Receive threat target indications and jamming pattern selection instructions from the external control interface; Based on the threat target indication, the set of pulse descriptors matching the threat target is queried and filtered from the first-in-first-out queue; According to the interference pattern selection instruction, an interference pattern is selected from the interference strategy library, and the modulation parameter set corresponding to the interference pattern is obtained; The set of modulation parameters corresponding to the selected interference pattern is used as the modulation parameter instruction and sent to the programmable logic section to control the generation of the baseband waveform of the interference signal.
6. The SAR radar jamming method based on high-speed data transmission according to claim 5, characterized in that, It also includes, in the programmable logic section, the steps of pre-storing and dynamically loading interference waveforms using memory: The solid-state drive connected to the programmable logic section pre-stores various complex-modulated long-time baseband interference waveform data. When the modulation parameter instruction issued by the processing system indicates that a pre-stored waveform needs to be loaded, the programmable logic unit initiates a direct memory access read operation on the solid-state drive through the hard core controller. Read pre-stored waveform data of a specified length from a specified address of the solid-state drive and load it into the memory inside the programmable logic section; During the interference signal generation process, the pre-stored waveform data is read cyclically from the memory inside the programmable logic section to replace the real-time generated baseband waveform of the interference signal; The pre-stored waveform data, which is read in a loop, is combined with real-time pulse synchronization information so that the pre-stored waveform data is output within the correct pulse period.
7. The SAR radar jamming method based on high-speed data transmission according to claim 6, characterized in that, The processing system also includes steps for evaluating interference effects and self-adjusting strategies. In the processing system section, interference effect evaluation data fed back from external electromagnetic environment monitoring equipment is received via a high-speed network interface; The interference effect evaluation data is analyzed to extract evaluation indicators that characterize the quality of the interference signal and the effectiveness of the interference. The evaluation index is compared with a preset interference effectiveness threshold to determine whether the current interference strategy is effective. If the current interference strategy is determined to be invalid, the processing system will autonomously select a backup interference style that is different from the current interference style from the interference strategy library. The set of modulation parameters corresponding to the selected backup interference pattern is updated to the new modulation parameter instruction, which is then sent to the programmable logic section to adjust the radiated interference signal.
8. The SAR radar jamming method based on high-speed data transmission according to claim 7, characterized in that, It also includes, within the programmable logic section, the step of implementing time-division multiplexing interference against multiple concurrent threat targets: In the programmable logic section, multiple independent signal processing channels and waveform generation channels are maintained in parallel; Each of the signal processing channels independently processes radio frequency signals from different threat targets and extracts their respective corresponding pulse descriptors; The processing system allocates different interference time slices to each threat target based on threat priority. In the programmable logic section, according to the time slice allocated by the processing system section, the corresponding waveform generation channel is controlled to be activated within the specified time slice to generate the target interference intermediate frequency digital signal for a specific threat target; A high-speed multiplexer switch is used to multiplex the multiple target interference intermediate frequency digital signals generated in different time slots into a single signal, which is then transmitted to the radio frequency transmitting front end for radiation.
9. The SAR radar jamming method based on high-speed data transmission according to claim 8, characterized in that, The step of interpolating and filtering the digital samples of the mixed signal to increase the sampling rate to a preset RF output sampling rate includes: Determine the integer multiple interpolation ratio between the initial sampling rate and the preset RF output sampling rate; Between every two adjacent digital samples of the signal after the mixing operation, zero-value samples are inserted in an integer multiple of the interpolation ratio minus one, forming a zero-value-filled sequence. Based on the preset RF output sampling rate, a low-pass filter with linear phase characteristics is designed, wherein the cutoff frequency of the low-pass filter is less than or equal to half of the initial sampling rate. The zero-padded sequence is convolved through the low-pass filter to suppress the high-frequency mirror spectrum introduced by the zero-value insertion; Gain compensation is performed on the output sequence after convolution to ensure that the signal power is not attenuated due to the interpolation process; From the output sequence after gain compensation, the portion containing valid data is extracted to obtain the digital signal sequence after interpolation and filtering; The sampling rate of the interpolated and filtered digital signal sequence is the preset radio frequency output sampling rate.