Radar networking anti-interference method based on broadband digital array radar software definition multifunctional digital radio frequency technology

Abstract

The invention belongs to the technical field of radars, and discloses a radar networking anti-interference method based on a digital array radar software definition multifunctional digital radio frequency technology. Various working modes of conventional radar narrowband and broadband detection, multi-station cooperative detection and anti-interference, external radiation source cooperative detection, single-station / double-station MIMO detection, channelized external electromagnetic environment cognitive reconnaissance, cooperative interference, detection and drying integration, multi-platform communication and the like can be realized at the same time. High-isolation signal frequency diversity is realized by using a wide-narrow band signal receiving and transmitting channelization technology, effective coding isolation diversity is realized by using coding pulses, and multifunctional signal time diversity is realized based on partial function time division multiplexing. According to the method, a set of broadband hardware system with composite functions is reused, electronic functions required by a radar networking system are achieved through different software, the purpose of software definition functions is achieved, and meanwhile the anti-interference capacity of the networking system is enhanced.

Description

Technical Field

[0001] The present invention belongs to the technical field of radar networking anti-interference, and in particular relates to a radar networking anti-interference method based on broadband digital array radar software-defined multifunctional digital radio frequency technology. Technical Background

[0002] As the modern information battlefield environment becomes increasingly complex, various threat sources and interference factors have put forward higher requirements on the performance of radar systems. When facing complex electromagnetic environments, traditional radar systems are often unable to achieve flexible frequency adjustment and switching of multiple functions, and it is difficult to cope with interference and detection needs from different directions and frequency bands. In the fields of military applications, border monitoring, emergency communications, etc., the multi-functional demand for radar detection, electronic warfare countermeasures and communication coordination is becoming more and more urgent.

[0003] In this context, multifunctional digital RF technology based on broadband digital array radar has gradually become a research hotspot. Broadband digital RF technology can cover a wider frequency range, has dynamic frequency agility, and can quickly switch the working frequency band when interference occurs, thereby improving the radar's anti-interference performance. In addition, this technology can realize the multifunctional integration of radar detection, electronic warfare countermeasures, and communications in the same system, laying the foundation for building a more flexible, stable and intelligent radar networking system.

[0004] This radar networking method based on software definition can not only flexibly adjust the working mode and achieve anti-interference positioning and suppression when facing enemy interference, but also realize directional communication between multiple radar nodes through intelligent multi-beamforming technology to ensure stable connectivity within the network. Therefore, this method is particularly suitable for building radar systems with high anti-interference capabilities, flexible networking and multi-task execution capabilities in modern battlefield environments with dense interference and diverse tasks, providing reliable technical support for real-time acquisition of tactical intelligence, interference countermeasures and information connectivity. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and propose a radar networking method based on software-defined multifunctional digital radio frequency technology of a broadband digital array radar.

[0006] In order to achieve the above object, the present invention adopts the following technical methods to achieve it.

[0007] The radar networking method based on software-defined multifunctional digital radio frequency technology of broadband digital array radar includes the following steps:

[0008] Step 1, dividing the corresponding frequency bands of narrowband radar signals, electronic warfare signals, and directional communication signals according to the working frequency bands;

[0009] Step 2: Select the directional communication antenna beam forming direction according to the station location;

[0010] Step 3, determining whether the radar working mode is a conventional networking transceiver mode or an electronic warfare mode;

[0011] Step 4: After being interfered, a radar in the networking system is silent and passive reception is used for interference positioning;

[0012] Step 5: After determining the location of the interfering party, suppress the interfering party and forward the interference. Perform broadband frequency agility on the networking system;

[0013] Step 6, loop to step 3, and determine whether the radar working mode is the conventional networking transceiver mode or the electronic warfare mode.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] (1) The present invention is a radar networking method based on software-defined multifunctional digital radio frequency technology of broadband digital array radar. Compared with the conventional fixed carrier frequency radar networking system, the present invention utilizes broadband digital radio frequency technology to achieve the integration of radar detection, electronic warfare and communication functions. Traditional radar systems are usually single-functional, while the present invention can switch working modes through software definition to adapt to different mission requirements, thereby improving the flexibility and practicality of the system.

[0016] (2) The radar networking method of the present invention based on the software-defined multifunctional digital radio frequency technology of the broadband digital array radar can locate the interference source and suppress or forward the interference by using a radar to silently and passively receive when the radar system is interfered. In addition, the broadband frequency agility function enables the radar to quickly adjust the working frequency band, effectively avoid interference, and enhance the system's survivability in complex electromagnetic environments.

[0017] (3) A radar networking method based on software-defined multifunctional digital radio frequency technology of broadband digital array radar was invented. The system has intelligent beamforming function, which can adjust the direction of communication antenna according to the location of radar station, and improve the stability and directivity of communication link. This is difficult to achieve in traditional networking structure, making networking communication more efficient and reliable.

[0018] A radar networking method invented based on software-defined multifunctional digital radio frequency technology of broadband digital array radar can perform cyclic judgment and automatic switching between conventional transceiver mode and electronic warfare mode, realizing adaptive adjustment of the system and making the radar networking structure more intelligent and self-protection capable. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A method for implementing a software-defined multifunctional digital radio frequency system representing a wideband digital array;

[0020] Figure 2 The anti-interference principle of the software-defined multifunctional digital radio frequency system of the broadband digital array is presented;

[0021] Figure 3 Indicates the radar network cross-positioning anti-interference strategy;

[0022] Figure 4 It represents the radar trace of station 1;

[0023] Figure 5 Indicates the target tracking result. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0025] like Figure 1 As shown, the method for implementing a software-defined multifunctional digital radio frequency system of a broadband digital array includes the following steps:

[0026] A radar networking method based on software-defined multifunctional digital radio frequency technology of broadband digital array radar comprises the following steps:

[0027] Step 1: Divide the corresponding frequency bands of narrowband radar signals, electronic warfare signals, and directional communication signals according to the working frequency bands; this step includes the following sub-steps:

[0028] Sub-step 1.1: Divide the frequency band. In this step, determine the frequency band of the receiving beam. Divide the frequency band into three parts: f1, f2, and f3, which are used for narrowband radar reception, electronic warfare and passive reconnaissance, and directional communication reception, respectively. Radar usually operates in the low-frequency to medium-frequency range to provide better penetration and detection range. It is recommended to choose L-band (1-2GHz) or S-band (2-4GHz); electronic warfare and passive reconnaissance use X-band (8-12GHz) or Ku-band (12-18GHz) to achieve high-precision signal analysis and interference; directional communication chooses C-band (4-8GHz) or K-band (18-26.5GHz), which is suitable for long-distance high-quality signal transmission.

[0029] Step 2: Select the directional communication antenna beamforming direction according to the station location; this step includes the following sub-steps:

[0030] Sub-step 2.1: Calculate the beamforming azimuth of the directional communication signal through the multi-station positions, and convert the earth-fixed coordinates between the multiple stations into local rectangular coordinates. First, convert the geographic coordinates of the sensor into earth-fixed coordinates, and then convert the target fixed coordinates into local rectangular coordinates centered on the sensor; the coordinate transformation formula is:

[0031]

[0032] Sub-step 2.2: Adjust the directional communication beam angle to the position of other stations in the networking system. The angle calculation formula is:

[0033]

[0034] like Figure 2 As shown, the anti-interference principle of the software-defined multifunctional digital radio frequency system of the broadband digital array includes the following steps:

[0035] Step 3: Determine whether the radar working mode is the conventional networking transceiver mode or the electronic warfare mode; this step includes the following sub-steps:

[0036] Sub-step 3.1: Determine whether the radar is interfered with based on the energy of the pulse compressed signal. If the pulse compressed signal energy is greater than a threshold, it is considered to be interfered with. The threshold is an empirical value that needs to be determined based on the radar gain and the environment.

[0037] Sub-step 3.2: When the networking system is subject to forwarding interference, the interference may not be identified through threshold detection due to the small amplitude of the echo signal energy increase. After the primary radar forms a point trace, point trace preprocessing is used to determine whether it is subject to forwarding interference. If the amplitude characteristics of the extracted dense point trace data conform to the uniform distribution, it is considered to be subject to forwarding interference.

[0038] Step 4: After confirming the interference, a radar in the networking system enters a silent state and locates the interference through passive reception; this step includes the following sub-steps:

[0039] Sub-step 4.1: When a radar station in the networking system is interfered with, shut down the transmitting module of one of the radar stations;

[0040] Sub-step 4.2: Position the passive jammer. Passive stations only generate interference traces, while active stations generate interference and target traces. The trace data generated by the current echo signal is transmitted to the data fusion center through the directional communication antenna. The single-frame interference signal of the active radar station is basically located at the same azimuth in a frame of echo data, and the interference trace data of the passive station is located on the straight line where the two stations are located. Figure 3 As shown, the data fusion center determines the location of the jammer through cross-positioning.

[0041] Step 5: After determining the location of the interferer, suppress / forward the interference and perform broadband frequency agility on the networking system; this step includes the following sub-steps:

[0042] Sub-step 5.1: Implement electronic countermeasures at the jammer's location, using co-frequency deception jamming or aiming frequency suppression jamming;

[0043] Sub-step 5.2: Adjust a beam of the broadband digital array to the tracking mode to track the jammer and continuously conduct electronic countermeasures against it;

[0044] Sub-step 5.3: The data fusion center redistributes the operating frequencies of the networked radar stations through software definition, and uses programmable broadband digital RF hardware to adjust the radar transmission signal to other bands. For example, when the L band is interfered, it can be adjusted to the S band;

[0045] Sub-step 5.4: Perform intra-pulse frequency agility through the channelized transmitter to improve the anti-interference capability of the networking system. If the intra-pulse frequency diversity number is L, the signal can be expressed as:

[0046]

[0047] Step 6: loop back to step 3 to determine whether the radar working mode is the conventional networking transceiver mode or the electronic warfare mode; this step includes the following sub-steps:

[0048] Sub-step 6.1: Determine whether the radar is interfered again;

[0049] Sub-step 6.2: If interference occurs again, continue to perform broadband frequency agility and implement electronic countermeasures;

[0050] Sub-step 6.3: If there is no interference, perform conventional radar narrow-band transceiver mode.

[0051] 1. Simulation conditions

[0052] The following simulation is used to illustrate that a dual-station radar is set up in the radar networking system. Assume that the rectangular coordinate system coordinates of one station are [30km, 0], and the rectangular coordinate system coordinates of the other station are [0, 0]. The two stations are networked using a radar networking method based on software-defined multifunctional digital radio frequency technology based on broadband digital array radar. The beam tracks the movement of the target. Assume that the target is in the same position as the jammer. Assume that the jammer responds quickly to station 1 after the radar pulse is irradiated, and implements slice forwarding interference on radar station 1. The target's flight speed is 500m / s, the flight altitude is 3000m, and it flies from the coordinates [0, 60km] for 100s to [50km, 60km]. The radar adopts tracking mode and reports the recorded points to the data fusion center every 100ms. Figure 4 100s radar point data transmitted from radar station 1 to the data fusion center.

[0053] 2. Simulation content and result analysis

[0054] The radar networking system substation determines whether it is interfered with.

[0055] If the radar substation is interfered with, the corresponding signal will be transmitted to the network fusion center.

[0056] After analysis, the network fusion center will jump the narrow-band detection frequency band of the interfered substation radar.

[0057] After receiving instructions from the networking fusion center, the substation communication module uses software-defined multifunctional digital radio frequency technology based on broadband digital array radar to jump to its own radar narrowband detection frequency band.

[0058] The interfered radar substation conducts electronic countermeasures on its own original frequency band to deceive / suppress the interference party.

[0059] After the radar narrowband detection signal frequency band jumps, the frequency diversity signal pre-set by the radar substation is used to track the interferer, further improving the substation's anti-interference capability.

[0060] The result of target tracking is as follows Figure 5 As shown. Figure 5 It can be seen that this method can implement effective electronic countermeasures against the jammer and enable the radar to successfully track the target.

[0061] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A radar networking method based on software-defined multifunctional digital radio frequency technology of broadband digital array radar, comprising the following steps: Step 1, dividing the corresponding frequency bands of narrowband radar signals, electronic warfare signals, and directional communication signals according to the working frequency bands; Step 2: Select the directional communication antenna beam forming direction according to the station location; Step 3, determining whether the radar working mode is a conventional networking transceiver mode or an electronic warfare mode; Step 4: After being interfered, a radar in the networking system is silent and uses passive reception to locate the interference; Step 5: After determining the location of the interfering party, suppress / forward the interference to the interfering party and perform broadband frequency agility on the networking system; Step 6, loop to step 3, and determine whether the radar working mode is the conventional networking transceiver mode or the electronic warfare mode.

2. According to claim 1, the method for determining the operating frequency band of narrowband radar signals, electronic warfare signals, and directional communication signals, step 1 comprises the following sub-steps: Sub-step 1.1, frequency band division, needs to determine the receiving beam frequency band in this step. Divide the three frequency bands f1, f2, and f3, which are used for narrowband radar reception, electronic warfare and unaided reconnaissance, and directional communication reception respectively. Radar usually operates in the low-frequency to medium-frequency range to provide better penetration and detection distance. It is recommended to allocate to the L-band (1-2GHz) or S-band (2-4GHz), which are commonly used in military radars. The L-band is suitable for longer distance detection, while the S-band is suitable for higher resolution radars. Electronic warfare and unaided reconnaissance usually require higher frequency bandwidth for high-precision signal analysis and interference. You can choose the X-band (8-12GHz) or Ku-band (12-18GHz). The high-frequency signals in these two bands are suitable for countering enemy radar reconnaissance and interference, and have good spatial resolution. Directional communication requires stable signal transmission, and the frequency should be selected in a range suitable for long-distance high-quality transmission. Usually, the C-band (4-8GHz) or K-band (18-26.5GHz) is used. The C-band is used in many communication systems, providing better anti-interference capabilities and transmission stability, while the K-band is suitable for higher bandwidth requirements.

3. According to claim 2, the method for selecting a directional communication antenna beamforming direction according to a station location comprises the following sub-steps: Sub-step 2.1, calculate the beamforming azimuth of the directional communication signal through the multi-station positions. Convert the earth fixed coordinates between the multiple stations into local rectangular coordinates. First, the sensor geographic coordinates (λ R ,φ R ,h R ) is converted to earth-fixed coordinates (X R , Y R , Z R ); then fix the target coordinates (X T , Y T , Z T ) is converted to the local rectangular coordinate (x) centered on the sensor T ,y T , z T ), its mathematical expression is: Sub-step 2.2, adjusting the directional communication beam angle to the positions of other stations in the networking system. Angle θ P The calculation method is:

4. According to claim 3, determining whether the radar working mode is a conventional networking transceiver mode or an electronic warfare mode, step 3 comprises the following sub-steps: Sub-step 3.1, judge whether the radar is interfered according to the energy of the pulse compression signal. If the pulse compression signal energy is greater than the threshold, it is considered to be interfered. The threshold is an empirical value and needs to be determined according to the radar gain and the environment. Sub-step 3.2, when the networking system is subject to forwarding interference, the energy increase of the echo signal is small, and the threshold detection may not be able to identify that the radar is interfered. After the radar forms a point trace, the point trace preprocessing method will be used to determine whether the radar is subject to forwarding interference. When the radar is subject to forwarding interference, a large amount of dense point trace data will be formed. The amplitude characteristics of the dense point trace data are extracted. If the amplitude characteristics of the point traces at different distances conform to the uniform distribution, it is considered that the radar is subject to forwarding interference.

5. According to claim 4, after being interfered, a radar in the networking system is silent and passive reception is used for interference positioning, characterized in that: Step 4 contains the following sub-steps: Sub-step 4.1, after confirming that a radar station in the networking system is interfered with, wait until other stations in the networking system are interfered with, and then shut down the radar transmission module of one of the stations. Sub-step 4.2, passive positioning of the jammer is performed. The passive station only generates interference traces, while the active station generates interference and target traces. The trace data generated by the current echo signal is transmitted to the data fusion center through the directional communication antenna. The single-frame interference signal of the active radar station is basically at the same azimuth within a frame of echo data. The interference trace data of the passive radar station is basically on the straight line where the two are located. By cross-positioning at the data fusion center, the jammer position is located at the intersection of the straight lines where the two stations are located.

6. After the location of the interfering party is determined according to claim 5, the interference is suppressed / forwarded. And broadband frequency agility is performed on the networking system, characterized in that: Step 5 contains the following sub-steps: Sub-step 5.1, implement electronic countermeasures at the location of the jammer, using co-frequency deception jamming or aiming frequency suppression jamming; Sub-step 5.2, adjusting one of the beams of the broadband digital array to a tracking mode, tracking the jammer, and continuously implementing electronic countermeasures against it; Sub-step 5.3: The network fusion center uses software to redefine the operating frequency of each network radar station through unified scheduling, and uses programmable broadband digital RF hardware to adjust the radar transmission signal to other bands. For example, if the interfered frequency band is L band, it can be adjusted to S band. Sub-step 5.4, use the channelized transmitter to perform intra-pulse frequency agility, and use the intra-pulse frequency agility signal to further improve the anti-interference ability of the networking system. The intra-pulse frequency diversity number is L, then the signal can be expressed as:

7. The method according to claim 6 loops to step 3, wherein it is determined that the radar operating mode is a conventional networking transceiver mode or an electronic warfare mode, characterized in that: Step 6 contains the following sub-steps: In sub-step 6.1, it is necessary to determine again whether the radar is interfered. Sub-step 6.2: If interfered, perform broadband frequency agility again and implement electronic countermeasures on the interfered frequency band. Sub-step 6.3: If there is no interference, perform conventional radar narrowband transmission and reception.

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