Distributed digital interference source dynamic sensitivity control method

Abstract

The invention provides a distributed digital interference source dynamic sensitivity control method, which can perform multi-stage control on the receiving sensitivity of a digital interference source according to a multi-target interference task, and performs radio frequency stage sensitivity control before a radio frequency signal enters a low noise amplifier to avoid signal saturation. When sensitivity control is carried out at the intermediate frequency stage, frequency coincidence judgment is carried out on intermediate frequency signals, dynamic attenuation is carried out on coincidence frequency bands, and fixed attenuation is carried out on non-coincidence frequency bands; and digital-level sensitivity control is performed on the signal after ADC sampling of the digital interference source, so that the receiving sensitivity of the digital interference source is further reduced, and the requirement of the digital interference source for large dynamic range receiving is met. Besides, in order to further reduce the influence of the multi-target interference on the time sequence, a time fault-tolerant interference source control method is adopted, a multi-target interference task is subjected to pulse-level control, and the interference source is synchronously controlled to carry out delay shadow hiding according to an interference gate output by repetition frequency tracking, so that the success rate of the multi-target interference is improved.

Description

Technical Field

[0001] The present application relates to the technical field of phased arrays, and in particular to a method for controlling dynamic sensitivity of distributed digital interference sources. Background Art

[0002] In modern warfare, electronic countermeasures have become an important part of dominating the battlefield. Radar is an important equipment for both sides to obtain battlefield information and operate weapons to attack. Therefore, electronic countermeasures are used to destroy the opponent's radar system and make the opponent's equipment that relies on radar ineffective. Therefore, in the face of increasingly complex electromagnetic environment competition, electronic countermeasures have become the key. In order to adapt to the needs of broadband and multi-target electronic warfare and improve the combat performance of jamming equipment, active jamming equipment is required to be able to continuously launch multiple jammings targeting different threat targets. When the jamming equipment and the reconnaissance and guidance equipment work at the same time, the antennas between the two devices will inevitably have a coupling effect. Therefore, if the coupled signal power of the receiving antenna exceeds the detection sensitivity, the jamming equipment will respond to the coupled signal, reducing the jamming effect of the jamming equipment on the real threat.

[0003] With the development of phased array technology, active phased array jammers have become an indispensable part of integrated radio frequency systems because of their advantages such as fast response, wide bandwidth, and multiple apertures. Active phased array jammers receive target signals through reconnaissance and guidance equipment through receivers and enter preprocessors to form reconnaissance parameters. On the basis of completing signal recognition, the main processor determines the frequency, azimuth, interference pattern and other parameters to counter different targets according to the model, working mode, and threat level of the opponent's radar, and generates corresponding interference that is distributed to different sub-apertures to form interference beams, thereby effectively interfering with threatening targets. Among them, interference signal pattern control, interference beam control, and interference frequency modulation are formed by digital interference sources under the control of resource scheduling.

[0004] Distributed digital jammers are capable of reconstructing multi-target jammer signals and precisely controlling jammer waveforms. However, due to the complexity of the mission and the coupling effect of reconnaissance jammers, when jammer signals are emitted, the coupled signals will enter the digital jammers, affecting the accuracy of the jammer waveform and thus reducing the jammer capability of active jammers. Summary of the invention

[0005] The present application provides a distributed digital interference source dynamic sensitivity control method, which can be used to solve the technical problem of interference to active interference equipment. The present application can perform multi-level sensitivity control on multi-target interference tasks, realize the isolation of the transmission and reception of multi-aperture distributed interference sources on the array, and complete the distributed interference source synchronization control based on time fault tolerance according to the multi-target interference tasks.

[0006] The present application provides a distributed digital interference source dynamic sensitivity control method, the method comprising:

[0007] Step 1, performing radio frequency level sensitivity control on the radio frequency signal of the reconnaissance guidance;

[0008] Step 2, down-convert the radio frequency to obtain an intermediate frequency signal;

[0009] Step 3, performing intermediate frequency sensitivity control;

[0010] Step 4, performing ADC sampling processing on the signal after the intermediate frequency level sensitivity control to obtain a digital signal;

[0011] Step 5, performing digital level sensitivity control on the sampled signal;

[0012] Step 6: The repetition frequency tracking control performs matched filtering based on the parameters including RF, DOA, and PW, and filters out the PDW outside the set value. Based on the time domain correlation characteristics of the radar pulse signal, the variable delay line is used to perform time domain correlation processing with the pulse signal stream output by the filter to establish tracking of the threat target and generate corresponding interference timing for the threat target;

[0013] Step 7, sending the interference wave gate to the synchronization control, performing time fault tolerance processing according to the interference wave gate of the multi-target interference task, and outputting a delayed shadowing enable signal;

[0014] Step 8, performing interference modulation on the sampled and attenuated digital signal according to the interference gate and the blanking enable signal;

[0015] Step 9: Perform DAC processing on the modulated signal to restore the digital signal to a baseband RF signal.

[0016] Furthermore, step 1, performing radio frequency level sensitivity control on the radio frequency signal guided by the reconnaissance, comprises:

[0017] The RF power automatically adjusts the link and dynamically controls the amplitude of the RF signal to ensure that the system RF sensitivity is controllable; the RF signal received by the antenna is subjected to a first-level limiting filtering amplification to ensure that the link is not saturated and prevent interference signals from burning through the link to obtain the primary signal S0, and then the signal power is controlled by the digitally controlled attenuator, and the intermediate signal S1 after digitally controlled attenuation is subjected to a second-level low-noise amplification to obtain the ultimate signal S2; at the same time, the ultimate signal S2 is controlled through the coupling branch. When the ultimate signal S2 does not meet the system power requirement, the digitally controlled attenuator is controlled to dynamically control the signal amplitude to prevent signal saturation; the low-noise amplified signal S2 is sent to the down-conversion module.

[0018] Further, step 3, performing intermediate frequency sensitivity control, includes:

[0019] The frequency coincidence judgment is performed on the intermediate frequency signal. The frequency coincidence judgment is performed on the guided intermediate frequency signal. When the intermediate frequency f guided by the task coincides with the intermediate frequency f guided by other tasks, i When they do not overlap, the corresponding intermediate frequency signal is fixedly attenuated G1; if the intermediate frequency f is the same as the intermediate frequency f guided by other tasks i If there are overlapping frequency bands, the overlapping frequency bands will be dynamically attenuated to a greater extent, and the attenuation of ΔG will be increased on the basis of the fixed attenuation G1.

[0020] Furthermore, step 5, performing digital level sensitivity control on the sampled signal, comprises:

[0021] Digital channelization is used to filter the digital signal of the front-end broadband sampling input and divide the broadband signal into several sub-frequency band components; channelized reception divides the RF signal into sub-channels and divides the broadband data into multi-channel narrowband sub-channel data for processing; channelized transmission processes the modulated signal, restores the broadband sampling signal after channel synthesis and outputs it.

[0022] Compared with the prior art, the present invention has the following significant advantages:

[0023] (1) A multi-level sensitivity control strategy is adopted to comprehensively consider the impact of multiple interference tasks on the transmission and reception of distributed digital interference sources. Multi-level sensitivity control is designed in the link. While executing multi-target interference tasks, the transmission and reception isolation between distributed digital interference sources can be achieved, thereby improving the interference effectiveness of active phased array jammers.

[0024] (2) A time-tolerant interference source control method is adopted. When multiple targets are interfered with, a pulse-level task control method is adopted. According to the interference gate output by repetition frequency tracking, other interference sources are synchronously controlled to delay and hide, thereby reducing the mutual influence of interference tasks in timing and improving the success rate of multiple target interference. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the reconnaissance guidance jamming system provided in the embodiment of the present application;

[0026] Figure 2 A flow chart of RF level sensitivity control provided in an embodiment of the present application;

[0027] Figure 3 A down-conversion branch diagram provided in an embodiment of the present application;

[0028] Figure 4 A tracking control flow chart provided for an embodiment of the present application;

[0029] Figure 5 A flow chart of dynamic sensitivity control of a digital interference source provided in an embodiment of the present application. DETAILED DESCRIPTION

[0030] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0031] The method provided in this application includes:

[0032] 1. Multi-level sensitivity control.

[0033] The multi-level sensitivity control method mainly controls the receiving sensitivity of the digital interference source in multiple levels according to the multi-target interference task, and realizes the isolation of the transmission and reception of the distributed digital interference source between the apertures. The multi-level sensitivity control is divided into RF level, IF level and digital level, and the receiving sensitivity of the digital interference source is controlled according to the transmission power classification of the interference task.

[0034] RF-level sensitivity control: When the active phased array jammer performs multi-target jamming, if the transmission power of the jamming task is too large, the signal entering the low-noise amplifier may be saturated, resulting in signal distortion and affecting the jamming effect. Therefore, the RF power is used to automatically adjust the link and dynamically control the amplitude of the RF signal to ensure that the system RF sensitivity is controllable; the RF signal received by the antenna is amplified by a first-level limiting filter to ensure that the link is not saturated and prevent the jamming signal from burning through the link to obtain signal S0, and then the signal power is controlled by a digitally controlled attenuator, and the digitally attenuated signal S1 is amplified by a second level of low noise to obtain signal S2; at the same time, signal S2 is controlled by a coupling branch. When signal S2 does not meet the system power requirement, the digitally controlled attenuator is controlled to dynamically control the signal amplitude to prevent signal saturation; the low-noise amplified signal S2 is sent to the down-conversion module.

[0035] Intermediate frequency sensitivity control: Intermediate frequency sensitivity control is performed before the ADC samples the digital interference source. On the one hand, the interference source storage frequency signal is too large, which leads to ADC saturation. On the other hand, the main consideration is whether the frequency band of the interference will affect the reception of another aperture. That is, when the interference tasks of the two apertures have overlapping frequency bands, the interference emitted by the apertures will definitely affect the storage frequency of the digital interference source. Therefore, when the interference task frequency bands overlap, the intermediate frequency sensitivity control is performed to attenuate the intermediate frequency signal sampled by the ADC to complete the transmission and reception isolation of the same-band interference of the digital interference source.

[0036]

[0037] As shown in formula (2), the frequency coincidence judgment is performed on the guided intermediate frequency signal. When the intermediate frequency f guided by the task is equal to the intermediate frequency f guided by other tasks, i When they do not overlap, the intermediate frequency signal is fixedly attenuated by G1; if the intermediate frequency f is the same as the intermediate frequency f guided by other tasks iIf there are overlapping frequency bands, the overlapping frequency bands are dynamically attenuated to a greater extent, and the attenuation of ΔG is increased on the basis of the fixed attenuation G1 to reduce the transmission and reception impact between the interference sources.

[0038] Digital-level sensitivity control: Digital-level sensitivity control is completed in the digital domain after the ADC sampling of the digital interference source. The maximum dynamic range of the intermediate frequency level sensitivity control is generally 20-30dB, which cannot meet the requirements of the isolation of the high-power interference source. Therefore, it is necessary to control the power of the sampled signal, increase the attenuation in the digital domain, that is, reduce the power value of the sampled signal, to further reduce the impact of the interference, and meet the requirements of the large dynamic range of the digital interference source. Digital channelization is used to filter the digital signal input by the front-end broadband sampling, and divide the broadband signal into several sub-band components; channelized reception divides the RF signal into sub-channels, and divides the broadband data into multi-channel narrowband sub-channel data for processing; after channelization, the data processing rate is reduced, and the signal-to-noise ratio is improved, which is conducive to interference modulation; channelized transmission processes the modulated signal, and after channel synthesis, the broadband sampling signal is restored and output.

[0039] 2. Synchronous control of distributed interference sources based on time fault tolerance.

[0040] The distributed interference source synchronization control based on time fault tolerance mainly considers the influence between the transmission and reception of digital interference sources in the time domain. At the moment when the interference is emitted, there is a step on the pulse front and the spectrum components are complex, which affects the reception of other digital interference sources. Therefore, time fault tolerance processing is performed in the time domain. The pulse-level task control method is used for multi-target interference. According to the interference wave gate output by repetition frequency tracking, the digital interference source emits interference at t1, and then other interference sources are synchronously controlled to be invisible within t1+Δt time, reducing the spectral components generated by the interference source at t1 to affect other digital interference sources, reducing the coupling effect of the interference task on the timing, and improving the success rate of multi-target interference.

[0041] Combined with the accompanying drawings, the present invention provides a distributed digital interference source dynamic sensitivity control method. The present application uses a multi-level sensitivity control method to achieve the isolation of the transmission and reception of the array multi-aperture distributed interference source and the distributed interference source synchronization control method based on time fault tolerance. Figure 1 As shown in the figure, the reconnaissance receiving antenna detects external signals, and after processing, the reconnaissance guidance equipment sends the radio frequency signal of the interference target to the active phased array jammer. The control module of the active phased array jammer completes the multi-target jamming task of multi-aperture on the array surface through the distributed digital jammer. The interference signal emitted by the transmitting aperture is coupled to the reconnaissance receiving antenna, and the coupled signal enters the digital jammer through the link, thereby affecting the interference signal generated by the modulation of the digital jammer, and finally affecting the success rate of the multi-target jamming of the active phased array jammer.

[0042] A flow chart of a distributed digital interference source dynamic sensitivity control method is shown in Figure 3 As shown, the following steps are included:

[0043] Step 1: Control the RF level sensitivity of the RF signal guided by reconnaissance. The flow chart is as follows: Figure 2 As shown, when the active phased array jammer performs multi-target jamming, if the transmission power of the jamming task is too large, the signal entering the low noise amplifier may be saturated, resulting in signal distortion and affecting the jamming effect. Therefore, the present invention designs an automatic RF power adjustment link to dynamically control the amplitude of the RF signal to ensure that the RF sensitivity of the system is controllable; the RF signal received by the antenna is amplified by a first-level limiting filter to ensure that the link is not saturated and prevent the jamming signal from burning through the link to obtain a primary signal S0, and then the power of the signal is controlled by a digitally controlled attenuator, and the intermediate signal S1 after digitally controlled attenuation is amplified by a second level of low noise to obtain the ultimate signal S2; at the same time, the ultimate signal S2 is controlled by a coupling branch, and when the ultimate signal S2 does not meet the system power requirement, the digitally controlled attenuator is controlled to dynamically control the signal amplitude to prevent signal saturation; the low-noise amplified signal S2 is sent to the down-conversion module.

[0044] Step 2: Down-convert the RF to obtain an intermediate frequency signal. The down-conversion branch is as follows: Figure 3 shown.

[0045] Step 3: Perform frequency overlap judgment on the intermediate frequency signal. Perform frequency overlap judgment on the guided intermediate frequency signal. When the intermediate frequency f guided by the task is equal to the intermediate frequency f guided by other tasks, i When they do not overlap, the corresponding intermediate frequency signal is fixedly attenuated G1; if the intermediate frequency f is the same as the intermediate frequency f guided by other tasks i If there are overlapping frequency bands, the overlapping frequency bands will be dynamically attenuated to a greater extent, and the attenuation of ΔG will be increased on the basis of the fixed attenuation G1.

[0046] Assuming that the interference frequency band of task 1 is 9GHz to 10GHz, and the interference frequency band of task 2 is 9.5GHz to 10.5GHz, then in task 1, the attenuation from 9GHz to 9.5GHz is 20dB, and the attenuation from 9.5GHz to 10GHz is 30dB, which means an additional attenuation of 10dB. The same treatment is performed for task 2, with an attenuation of 30dB from 9.5GHz to 10GHz and 20dB from 10GHz to 10.5GHz.

[0047] Step 4, performing ADC sampling processing on the signal after the intermediate frequency level sensitivity control to obtain a digital signal;

[0048] Step 5: Perform digital-level sensitivity control on the sampled signal. Digital channelization is mainly used to filter the digital signal input by the front-end broadband sampling, and divide the broadband signal into several sub-band components. Channelized reception divides the RF signal into sub-channels, and divides the broadband data into multi-channel narrowband sub-channel data for processing. After channelization, the data processing rate is reduced, and the signal-to-noise ratio is improved, which is conducive to interference modulation. Channelized transmission processes the modulated signal, and after channel synthesis, the broadband sampling signal is restored and output. Increasing attenuation in the digital domain means reducing the power value of the sampled signal.

[0049] Step 6: The repetition frequency tracking control performs matched filtering based on the parameters including RF, DOA, and PW, and filters out the PDW outside the set value. Based on the time domain correlation characteristics of the radar pulse signal, the variable delay line is used to perform time domain correlation processing with the pulse signal stream output by the filter to establish tracking of the threat target, and generate corresponding interference timing for the threat target, and feedback the tracking status to the synchronous control, such as Figure 4 shown.

[0050] Step 7, the interference wave gate is sent to the synchronization control, time fault tolerance processing is performed according to the interference wave gate of the multi-target interference task, and a delayed shadowing enable signal is output.

[0051] Step 8, performing interference modulation on the sampled and attenuated digital signal according to information such as the interference gate and the blanking enable signal;

[0052] Step 9: Perform DAC processing on the modulated signal to restore the digital signal to a baseband RF signal.

[0053] This application adopts a multi-level sensitivity control method and a distributed interference source synchronization control method based on time fault tolerance to achieve the isolation of transmission and reception during multi-target interference by multi-aperture distributed interference sources on the array. According to the multi-target interference task, the receiving sensitivity of the digital interference source is controlled at multiple levels, and the analog domain and digital domain sensitivity control of the signal are completed from the RF level, the intermediate frequency level and the digital level respectively. The pulse-level task control method is adopted, and according to the interference wave gate output by the repetition frequency tracking, the interference source is synchronously controlled to delay the shadowing, reduce the coupling effect of the interference task on the timing, and improve the success rate of multi-target interference.

[0054] The above-described embodiments of the present application do not constitute a limitation on the protection scope of the present application.

Claims

1. A distributed digital interference source dynamic sensitivity control method, characterized in that: The method comprises: Step 1, performing radio frequency level sensitivity control on the radio frequency signal of the reconnaissance guidance; Step 2, down-convert the radio frequency to obtain an intermediate frequency signal; Step 3, performing intermediate frequency sensitivity control; Step 4, performing ADC sampling processing on the signal after the intermediate frequency level sensitivity control to obtain a digital signal; Step 5, performing digital level sensitivity control on the sampled signal; Step 6: The repetition frequency tracking control performs matched filtering based on the parameters including RF, DOA, and PW, and filters out the PDW outside the set value. Based on the time domain correlation characteristics of the radar pulse signal, the variable delay line is used to perform time domain correlation processing with the pulse signal stream output by the filter to establish tracking of the threat target and generate corresponding interference timing for the threat target; Step 7, sending the interference wave gate to the synchronization control, performing time fault tolerance processing according to the interference wave gate of the multi-target interference task, and outputting a delayed shadowing enable signal; Step 8, performing interference modulation on the sampled and attenuated digital signal according to the interference gate and the blanking enable signal; Step 9: Perform DAC processing on the modulated signal to restore the digital signal to a baseband RF signal.

2. The method according to claim 1, characterized in that: Step 1, performing radio frequency level sensitivity control on the radio frequency signal for reconnaissance guidance; comprising: The RF power automatically adjusts the link and dynamically controls the amplitude of the RF signal to ensure that the system RF sensitivity is controllable; the RF signal received by the antenna is subjected to a first-level limiting filtering amplification to ensure that the link is not saturated and prevent interference signals from burning through the link to obtain the primary signal S0, and then the signal power is controlled by the digitally controlled attenuator, and the intermediate signal S1 after digitally controlled attenuation is subjected to a second-level low-noise amplification to obtain the ultimate signal S2; at the same time, the ultimate signal S2 is controlled through the coupling branch. When the ultimate signal S2 does not meet the system power requirement, the digitally controlled attenuator is controlled to dynamically control the signal amplitude to prevent signal saturation; the low-noise amplified signal S2 is sent to the down-conversion module.

3. The method according to claim 1, characterized in that Step 3, performing intermediate frequency sensitivity control; including: The frequency coincidence judgment is performed on the intermediate frequency signal. The frequency coincidence judgment is performed on the guided intermediate frequency signal. When the intermediate frequency f guided by the task coincides with the intermediate frequency f guided by other tasks, i When they do not overlap, the corresponding intermediate frequency signal is fixedly attenuated G1; if the intermediate frequency f is the same as the intermediate frequency f guided by other tasks i If there are overlapping frequency bands, the overlapping frequency bands will be dynamically attenuated to a greater extent, and the attenuation of ΔG will be increased on the basis of the fixed attenuation G1.

4. The method according to claim 1, characterized in that: Step 5, performing digital level sensitivity control on the sampled signal; comprising: Digital channelization is used to filter the digital signal of the front-end broadband sampling input and divide the broadband signal into several sub-frequency band components; channelized reception divides the RF signal into sub-channels and divides the broadband data into multi-channel narrowband sub-channel data for processing; channelized transmission processes the modulated signal, restores the broadband sampling signal after channel synthesis and outputs it.

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