Deception jamming method and device based on identification friend or foe system M4 interrogator

Abstract

The invention discloses a deception jamming method and device based on an M4 interrogator of an identification friend or foe system, and belongs to the technical field of radar countermeasure, and the deception jamming method comprises the steps: starting timing after detecting a rising edge of a synchronization pulse P4 in an M4 interrogation signal, carrying out the waveform feature matching according to the features of the M4 interrogation signal, and carrying out the coding to generate an M4 response'three-pulse 'signal, all possible interference response signals are emitted according to the generation time of the M4 response signals, effective deception interference is formed, the intercepted M4 inquiry signals are converted into digital information to be stored, and the problem that an enemy M4 interrogator cannot be effectively interfered due to the fact that response delay codes in ciphertext information cannot be obtained is solved. An enemy M4 interrogator can be effectively resisted in a battlefield environment, and the purpose of deception jamming is achieved; and according to the working mechanism of the identification friend or foe M4 system in the Mark XII standard, the anti-interference capability and the active interference capability of the own identification friend or foe system are evaluated.

Description

Technical Field

[0001] The present invention belongs to the technical field of radar countermeasure, and specifically relates to a spoofing interference method and device based on an IFF system M4 interrogator. Background Art

[0002] An IFF (Identification Friend or Foe) system is used to identify the friend-or-foe attributes of targets detected and discovered by a radar, form a complete battlefield situation, and provide accurate intelligence information for military command departments. It is also a main combat equipment for coordinating weapon systems. IFF countermeasure is a comprehensive countermeasure activity that intercepts, identifies, and locates the signals of the enemy's IFF system, and guides interference devices to attack, interfere with, or damage the enemy's IFF system.

[0003] The main technical feature of IFF of the M4 system is to encrypt the interrogation information in the uplink 1030 MHz frequency band to generate interrogation ciphertext information. The interrogation ciphertext information contains a random response delay code, which is "prescribed" by the interrogator and carried through the interrogation ciphertext information. The transponder receives and decrypts the interrogation ciphertext information and extracts the "random response delay code", and generates a corresponding response signal in accordance with this "prescription". For non-friendly or enemy M4 transponders, since they cannot decrypt the interrogation ciphertext information, they cannot obtain the "prescribed" random response delay code, thus generating incorrect response signals. In the downlink 1090 MHz frequency band, after the M4 interrogator receives and processes the response signal, it determines whether the arrival time of the response signal meets the "prescribed" time for generating this response signal. If it meets, it is determined to be friendly or its own; otherwise, it is determined to be "enemy", and the identification information is reported to the intelligence command center.

[0004] The M4 system is an IFF system that conforms to the Mark XII standard. As the main device for identifying the friend-or-foe attributes of combat targets, the traditional noise suppression interference method requires the interference equipment to have high-power emission capabilities to obtain better interference effects, which causes great difficulties in engineering. In addition, high-power emission is likely to expose the "position" of itself (the interference source), making it easy to be discovered by the enemy and attacked, greatly reducing the battlefield survival ability.

[0005] Based on the above, it is urgent to develop an interference strategy for the M4 interrogator of the IFF system to generate all possible "false" M4 response signals, so as to effectively reduce the combat effectiveness of the enemy's M4 interrogator and gain battlefield survival time for one's own side. Summary of the Invention

[0006] In view of this, in order to solve the above problems existing in the prior art, the purpose of the present invention is to provide a deception interference method and device based on an IFF system M4 interrogator, so as to solve the problem that the enemy M4 interrogator cannot be effectively interfered due to the inability to obtain the "response delay code" in the M4 interrogation ciphertext information, so as to improve the working efficiency of effectively countering the enemy M4 interrogator in the battlefield environment and achieve the purpose of deception interference; at the same time, according to the working mechanism of the IFF M4 system in the Mark XII standard, a battlefield electromagnetic environment can be constructed to evaluate the anti-interference ability and active interference ability of one's own IFF system.

[0007] The technical solution adopted by the present invention is: a deception interference method based on an IFF system M4 interrogator, and the deception interference method includes: S1: Receive the IFF signal at the L band with a receiving center frequency of 1030Mhz ± 0.2Mhz. S2: According to the requirements of the Mark XII standard, determine whether the received IFF signal is an M4 interrogation signal and generate a "correlation peak" signal. S3: Based on the rising edge of the synchronization pulse P4 in the M4 interrogation signal as the timing reference, encode and generate the M4 response "three-pulse" digital information, and extract the ciphertext information of the received M4 interrogation signal according to the "correlation peak" signal. S4: Store the M4 response "three-pulse" digital information and the ciphertext information of the M4 interrogation signal. S5: Generate a fixed response delay time for the M4 interrogation signal according to the timing information, and generate 16 groups of flag pulse signals of random response delay codes corresponding to the fixed response delay time according to the generation mechanism of the random response delay code. S6: According to the 16 groups of flag pulse signals of random response delay codes, read out the stored M4 response "three-pulse" digital information and generate 16 groups of interference response signals corresponding to the received M4 interrogation signal.

[0008] Further, in S1, the method for receiving the IFF signal is: S101: Receive the RF signal with a center frequency of 1030MHz ± 0.2MHz in the L band. S102: Mix the RF signal with the local oscillator signal of 1170MHz after filtering and amplification to generate a 140MHz intermediate frequency signal. S103: Perform ASK demodulation on the 140Mhz intermediate frequency signal to obtain the demodulated signal. S104: Perform amplitude processing on the demodulated signal to obtain the corresponding amplitude information.

[0009] Further, in S2, the specific method is: S201: collecting the width and amplitude information of the synchronization pulses P1, P2, P3, P4, and P5 in the friend-or-foe identification signal in real time; S202: comparing with the waveform timing characteristics of the M4 interrogation signal; S203: Determine whether it is an M4 interrogation signal, if so, proceed to the next step; if not, discard the friend-or-foe identification signal; S204: Using the rising edge of the synchronization pulse P1 in the M4 interrogation signal as a timing reference, a "correlation peak" signal is generated at 10 μs, which serves as the starting position for the subsequent extraction of the ciphertext information of the M4 interrogation signal.

[0010] Furthermore, in S3, the M4 response "three-pulse" digital information is encoded and generated according to the M4 response "three-pulse" waveform characteristics specified in the Mark XII standard; and the ciphertext information of the M4 interrogation signal is collected at the rising edge of the "correlation peak" signal according to the waveform timing characteristics of the M4 interrogation signal specified in the Mark XII standard.

[0011] Furthermore, the M4 response "three-pulse" digital information is a baseband code element composed of 0 and 1; the ciphertext information of the M4 inquiry signal is an information unit composed of 0 and 1.

[0012] Further, in S5, the random response delay code generation mechanism includes: S501: According to the MARK XII standard, the rising edge of the synchronization pulse P4 in the M4 interrogation signal is used as the timing reference; S502: According to the occurrence time of the i-th group of interference response signals t=202+5.25×Nμs±1.25μs (N=0,1,2...15); generate the i-th group of random response delay code j of the marker pulse signal Pj, wherein i=1,2,3...16; N=j=i-1.

[0013] Further, in said S6, it includes: S601: extract the rising edges of the marker pulse signals of 16 groups of random response delay codes in sequence and use them as valid read signals to read out the M4 response "three pulses" digital information in sequence; S602: Process the "three-pulse" digital information of M4 response and output an ASK demodulated signal of 1090Mhz±1MHz; S603: After amplifying the ASK demodulated signal, 16 groups of interference response signals are generated in sequence and transmitted.

[0014] Furthermore, the deception interference method also includes: sending the ciphertext information of the M4 interrogation signal acquired and stored in this interception to the decryption system.

[0015] The present invention also discloses a deception interference device based on an IFF system M4 interrogator. The deception interference device includes: A signal processing module, which is used to run the above-mentioned deception interference method based on the IFF system M4 interrogator; A transceiver module communicatively connected to the signal processing module. The transceiver module is connected to an antenna and is used to detect and receive M4 interrogation signals and transmit M4 response signals; A digital storage module communicatively connected to the signal processing module, which is used to store the M4 response "three-pulse" digital information and the ciphertext information of the M4 interrogation signal; A power supply module, which is used to supply power to the signal processing module and the transceiver module respectively; Further, the signal processing module is communicatively connected to a deciphering system and an external control system. According to the command of the external control system, the ciphertext information of the M4 interrogation signal acquired and stored this time is sent to the deciphering system.

[0016] The beneficial effects of the present invention are as follows: 1. The deception interference method based on the IFF system M4 interrogator provided by the present invention belongs to the "deception interference" method. According to the detection, detection and recognition of the M4 interrogation signal, a false M4 response signal corresponding to the "current" interrogation signal is manufactured. At the same time, the waveform characteristics of the false M4 response signal conform to the Mark XII standard, and the response time covers all possible 16 situations; it makes it difficult for the enemy interrogator to distinguish the true from the false, causing "target" confusion, and can effectively reduce the combat effectiveness of the enemy M4 interrogator. The enemy weapon platform cannot obtain the "true" and "effective" friendly targets in real time, delaying the fighter opportunity; 2. Compared with the "noise suppression" active and high-power interference method, the deception interference device based on the IFF system M4 interrogator provided by the present invention has a full-coverage "deception interference" method. Each interference is triggered by the interrogation of the enemy M4 interrogator, with better "concealment", reducing the probability of "exposing" the air interference platform and improving the battlefield survival ability of this interference device; 3. The deception interference device based on the IFF system M4 interrogator provided by the present invention adopts a modular design for the whole machine hardware, with a small volume and wide platform applicability. External control interfaces and power supply interfaces are reserved, and it can be integrated into airborne electronic devices such as reconnaissance and interference; 4. The deception interference method and device based on the IFF system M4 interrogator provided by the present invention are proposed based on the working mechanism of the IFF system M4, fully meeting the requirements of the Mark XII standard. On the one hand, it can construct an electromagnetic combat environment simulating the Western system M4 to verify and enhance the capabilities of domestic levy equipment in the electromagnetic combat environment and verify the working efficiency of domestic radar devices in a complex electromagnetic environment. On the other hand, it can be used to test the anti-interference performance of domestic IFF equipment, especially to test and evaluate the anti-interference ability of domestic IFF M4 interrogator equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is the logical flow block diagram of the deception interference method based on the IFF system M4 interrogator provided by the present invention; Figure 2 is the ASK demodulation principle diagram of the M4 interrogation signal in the deception interference method based on the IFF system M4 interrogator provided by the present invention; Figure 3 is the waveform feature schematic diagram of the M4 interrogation signal in the deception interference method based on the IFF system M4 interrogator provided by the present invention; Figure 4 is the waveform feature schematic diagram of the M4 reply "three-pulse" signal in the deception interference method based on the IFF system M4 interrogator provided by the present invention; Figure 5 is the time slot diagram of generating 16 groups of M4 interference reply signals in the deception interference method based on the IFF system M4 interrogator provided by the present invention; Figure 6 is the internal module architecture diagram of the deception interference device based on the IFF system M4 interrogator provided by the present invention; Figure 7 is the architecture diagram of the signal processing module in the deception interference device based on the IFF system M4 interrogator provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] The embodiments of the present application will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar modules or modules with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present application and should not be construed as a limitation to the present application. On the contrary, the embodiments of the present application include all changes, modifications, and equivalents falling within the spirit and scope of the appended claims.

[0019] Embodiment 1 According to the working mechanism, principle and signal characteristics of the Identification Friend or Foe (IFF) M4 based on the MARK XII standard, a spoofing interference method based on the IFF system M4 interrogator is disclosed in this embodiment. The ciphertext information of the M4 interrogation signal sent by the M4 interrogator contains a random response delay code for the 1090 MHz response "agreement" of the M4 downlink; and the M4 response signal is a fixed response "three-pulse" signal, and the moment when the transponder sends the response "three-pulse" signal is jointly determined by the fixed response delay time and the random response delay time. Among them, the fixed response delay time is 202 μs, and the random response delay time is specified according to the 4-bit random response delay code in the ciphertext information. Therefore, the generation moment of each M4 response signal is randomly jittered, and there are 16 possible moments of jitter (determined by the 4-bit random response delay code according to the MARK XII standard).

[0020] On the other hand, since the waveform of the M4 response signal consists of fixed three pulses, the width of a single pulse is a duration of 0.45 μs ± 0.1 μs, and the duration of the three pulses of each group of M4 response signals is 5.25 μs; the real time of each M4 response signal is t = 202 + 5.25×N μs (N = 0, 1, 2,..., 15). According to the jitter law of the M4 random response moment, for each M4 interrogation signal, 16 possible interference response signals are transmitted during the response, so that the enemy's M4 interrogator can obtain a piece of information that can be "correctly decoded" from these 16 situations each time, and can obtain "stable distance correlation", so that the interfered M4 interrogator is always in a "busy state", achieving the effects of "spoofing interference" and "blocking interference", and effectively reducing the combat effectiveness of the enemy's M4 interrogator.

[0021] Specifically, as Figure 1 shown, this spoofing interference method includes: S1: Receive the IFF signal at the L band with a receiving center frequency of 1030 MHz ± 0.2 MHz. Among them, the operating method for receiving and processing the IFF signal includes: S101: Receive the radio frequency signal with a center frequency of 1030 MHz ± 0.2 MHz in the L band. Among them, the technical indicators of the received signal are: the detectable 3 dB bandwidth range is 8 MHz to 10 MHz, the receiving decoding sensitivity (MTL) is -77 dBm ± 3 dB, and the receiving dynamic range is ≥ 50 dB; S102: The radio frequency signal is mixed with the local oscillator signal of 1170 MHz after filtering and amplification to generate a 140 MHz intermediate frequency signal; S103: As Figure 2As shown, the intermediate frequency signal is sent to the FPGA for digital demodulation after ADC data acquisition. The signal is first digitally down-converted (DDC) by using the correlation demodulation method, and then the ASK demodulation is completed by taking the square root of the signal. S104: Perform amplitude processing on the demodulated signal to output corresponding amplitude information, wherein the amplitude of the pulse signal demodulated by ASK is: parallel 8-bit quantized data.

[0022] S2: According to the Mark XII standard requirements, determine whether the received IFF signal is an M4 interrogation signal, and generate a "correlation peak" signal for the M4 interrogation signal. Figure 3 As shown in the figure, for the M4 interrogation signal, it includes 4 fixed synchronization header pulses (P1~P4), 1 sidelobe suppression pulse (P5) and 32 randomly jumping encrypted information pulses (P6~P37). The transponder loaded with the same key can parse the correct key information from these 32 randomly jumping encrypted information pulses and make an identification response. The pulse of the M4 response signal is a fixed three-pulse form, but the response delay will also randomly jump according to the different 32 bits of random information each time.

[0023] The characteristics of the M4 interrogation signal are: the interval between adjacent pulses is 2±0.1µs, and the pulse width is 0.5±0.1µs; P1, P2, P3, and P4 are synchronization pulses; P5 is an SLS (sidelobe suppression) pulse; P6 to P37 are encrypted information pulses, and the encrypted information pulse data changes with time; pulse rising edge: ≤ 0.1µs, falling edge: ≤ 0.2µs.

[0024] The specific method of this S2 step is: S201: collecting the width and amplitude information of the synchronization pulses P1, P2, P3, P4, and P5 in the detected friend-or-foe identification signal in real time; S202: Compare the waveform timing characteristics of the M4 interrogation signal according to the Mark XII standard; S203: Determine whether it is an M4 interrogation signal. If so, proceed to the next step; if not, discard the friend-or-foe identification signal. The specific determination process is as follows: For the detection signal that meets the requirements of a total width of a single pulse of 2µs, a width of a high level "1" in a single pulse of 0.5±0.1µs, a pulse rising edge: ≤ 0.1µs, a falling edge: ≤ 0.2µs; an interval between adjacent pulse rising edges of 2µs; a time from the rising edge of pulse P1 to the rising edge of pulse P4 of 6µs, and a time from the rising edge of pulse P1 to the rising edge of pulse P5 of 8µs, if the amplitude of pulse P5 is less than the amplitude of pulse light P4, it is confirmed as an M4 interrogation signal; otherwise, it is considered to be a sidelobe signal and is suppressed, and this frame of signal is discarded.

[0025] S204: Taking the rising edge of the synchronization pulse P1 in the M4 interrogation signal as the timing reference, generate a "correlation peak" signal at 10 μs as the starting position for extracting the ciphertext information of the M4 interrogation signal in the following steps; meanwhile, for the timing pulses P6 to P37, the width of the interrogation ciphertext information data of 32 pulses is 64 μs in total, and the width of each pulse is 2 μs.

[0026] S3: Taking the rising edge of the synchronization pulse P4 in the M4 interrogation signal as the timing reference, encode and generate the M4 response "three-pulse" digital information, and extract the ciphertext information of the received M4 interrogation signal according to the "correlation peak" signal. Specifically, according to the waveform characteristics of the M4 response "three-pulse" stipulated by the MarkXII standard, encode and generate the M4 response "three-pulse" digital information; among them, as Figure 4 shown, the waveform characteristics of the M4 response "three-pulse" signal are: pulse width: 0.5 ± 0.1 μs; adjacent pulse interval: 1.75 ± 0.1 μs; pulse rising edge: ≤ 0.1 μs, falling edge: ≤ 0.2 μs; According to the waveform timing characteristics of the M4 interrogation signal stipulated by the Mark XII standard, collect the ciphertext information of the M4 interrogation signal at the rising edge of the "correlation peak" signal.

[0027] S4: Store the M4 response "three-pulse" digital information. The M4 response "three-pulse" digital information is a baseband symbol composed of 0s and 1s. After being converted into a data packet, according to the transmission protocol with the digital storage module, it is written into the digital storage module through the NVMe bus to complete the storage, and the writing speed can reach 5000 MB / s. At the same time, store the ciphertext information of the M4 interrogation signal. The ciphertext information of the M4 interrogation signal is an information unit composed of 0s and 1s. After being converted into a data packet, according to the transmission protocol with the digital storage module, it is written into the corresponding address of the digital storage module through the NVMe bus to complete the storage.

[0028] S5: Generate the fixed response delay time of the M4 interrogation signal according to the timing information, and according to the generation mechanism of the random response delay code, sequentially generate the flag pulse signals of 16 groups of random response delay codes corresponding to the fixed response delay time; in the S5, the generation mechanism of the random response delay code includes: S501: According to the stipulation of the MARK XII standard, taking the rising edge of the synchronization pulse P4 in the M4 interrogation signal as the timing reference; specifically, using the internal 80 MHz clock signal as the main processing clock, with a corresponding period of 12.5 ns, design the timing circuit; S502: According to the occurrence time of the i-th group of interference response signals, t=202+5.25×Nμs±1.25μs (N=0,1,2...15); generate the i-th group of random response delay code j of the marker pulse signal Pj, where i=1,2,3...16; N=j=i-1. They are as follows: The appearance time of the first group of interference response signals is t=202+5.25×0μs±1.25μs (N=0,1,2...15); the first group of random response delay code is 0, and the marker pulse signal P0 is generated, with a width of 25ns; The appearance time of the second group of interference response signals is t=202+5.25×1μs±1.25μs (N=0,1,2...15); the second group of random response delay code is 1, and the width is 25ns; The appearance time of the 16th group of interference response signals is t=202+5.25×16μs±1.25μs (N=0,1,2...15); the 16th group of random response delay code is generated as the marker pulse signal P15 of 15, and the width is 25ns.

[0029] S6: According to the marker pulse signals of the 16 groups of random response delay codes, the stored M4 response "three pulses" digital information is read out and 16 groups of interference response signals corresponding to the M4 interrogation signal received this time are generated, which specifically includes: S601: extract the rising edges of the marker pulse signals of 16 groups of random response delay codes in sequence and use them as valid read signals to read out the M4 response "three pulses" digital information in sequence; S602: Process the "three-pulse" digital information of M4 response and output an ASK demodulated signal of 1090Mhz±1MHz; S603: After amplifying the ASK demodulated signal, 16 groups of interference response signals are generated in sequence and transmitted.

[0030] like Figure 5 As shown, the timing starts from the rising edge of the synchronization pulse P4 in the M4 inquiry signal. When the timing reaches 202μs+5.25×0±1.25μs, the first group of interference response signals are emitted; when the timing reaches 202μs+5.25×1±1.25μs, the second group of interference response signals are emitted; ...; when the timing reaches 202μs+5.25×15±1.25μs, the 16th group of interference response signals are generated in sequence.

[0031] S7: Perform self-test on the friend-or-foe identification system M4 interrogator according to a predetermined period and send the self-test information to the external control system. Specifically: S701: collect status information of each unit module in the interference host in real time to form self-check information of the whole machine; S702: Report the self-test information to the external control system according to the reporting period (usually 1 second) of the self-test information. The reporting period of the self-test information may also be changed according to the command of the external control system.

[0032] S8: According to the command of the external control system, the ciphertext information of the M4 interrogation signal acquired and stored in this interception is sent to the decryption system. The ciphertext information of the M4 interrogation signal is provided to the intelligence system of the party and used by the lower-level decryption system. By continuously intercepting and accumulating more samples, conditions are created for further decryption of the enemy's interrogation encryption algorithm and key. Specifically: S801: Read the digital storage module in response to the command of the external control system to obtain the ciphertext information of the M4 interrogation signal stored after detection; S802: The ciphertext information of the M4 query signal is used as a decryption sample and sent to the decryption system through the NVMe high-speed bus according to the communication protocol between the next-level decryption system.

[0033] The deception jamming method of this embodiment proposes a method for detecting and judging the M4 interrogation signal based on the M4 "interrogation-response" mechanism of friend-or-foe identification in the Mark XII standard, and proposes a method for calculating the fixed response delay time and the random response delay time based on the generation mechanism of the M4 response signal, that is, the M4 response signal generation time = fixed response delay time (202μs) + random response delay time (determined by the random response delay code), the time for generating a "false" response signal, and based on the 16 response signals corresponding to a single M4 interrogation, full coverage jamming of the 16 response signals is achieved, so that the enemy M4 interrogator can always find the "correct" M4 response signal among the 16 response signals and obtain "stable distance correlation", so that the interfered M4 interrogator is always in a "busy state", reducing the combat effectiveness of the enemy M4 interrogator and achieving the purpose of deception jamming. At the same time, it has good "concealment", reduces the probability of "exposing" the aerial jamming host, and improves the battlefield survivability of the jamming device.

[0034] Example 2 Based on the deception jamming method based on the IFF system M4 interrogator provided in Example 1, this embodiment further provides a deception jamming device based on the IFF system M4 interrogator, specifically, Figure 6 As shown, the deception interference device includes: ① Signal processing module, the signal processing module is used to run the deception interference method logic based on the M4 interrogator of the friend-or-foe identification system in the above embodiment 1. Figure 7As shown, the signal processing module mainly uses ARM and FPGA as the signal processing cores. The FPGA realizes the processing of encoded and decoded signals, the ARM realizes protocol parsing and data packetization, and the driver and interface circuit realize electrical matching and internal and external signal isolation. The FPGA transmits addresses, data, and commands to and from the ARM. The FPGA receives signals in the 1030Mhz frequency band after AD conversion, and the FPGA and the digital storage module transfer information through the NVMe protocol interface. The ARM is communicatively connected to an EPROM memory, and the ARM transmits self-check status information to the external control system through a reset circuit and receives switch and response information through a 422 interface circuit. This signal processing module mainly realizes functions such as decoding and decision-making of M4 interrogation signals, encoding of response interference signals, control of input / output suppression interfaces, communication with the external control system through the RS422 interface, and bus communication with the digital storage module. The FPGA model used is the XC7K325T-2FFG900I chip, which contains 407,600 Slice Registers, 203,800 Slice LUTs, 445 Block RAM / FIFOs, and has 500 I / O ports. Chips from Xilinx, Altera, or other similar manufacturers can also be selected as alternatives. The embedded processor ARM uses the STM32F746VGT6 chip, and other similar chips can also be used as alternatives.

[0035] ② The transceiver module is communicatively connected to the signal processing module. The circulator in the transceiver module is connected to an external antenna through a radio frequency interface. The antenna is used to detect M4 interrogation signals and transmit M4 response signals. The working frequency band for receiving M4 interrogation signals through the antenna is 1030MHz ± 3MHz, and the transmitting working frequency band is 1090MHz ± 1MHz. Specifically, the transceiver module includes a transmitting unit and a receiving unit. The transmitting unit modulates the "false" response interference signal from the signal processing module to the 1090MHz frequency, obtains the required power value after multiple stages of power amplification, and transmits it through the antenna via the radio frequency interface unit according to an external response interference instruction. This radio frequency interface unit is centered around DDS, has a 3.5GHz clock, and can control the DDS more precisely and accurately to ensure that the single pulse of the M4 interference response signal meets 0.50μs ± 0.1μs, the pulse rise time ≤ 100 ns, and the pulse fall time ≤ 200 ns.

[0036] The receiving unit is used to perform a series of processes on the radio frequency input signal, such as filtering, amplification, down-conversion, intermediate frequency amplification and filtering, and video detection, to obtain an intermediate frequency signal and a video detection signal with a certain amplitude.

[0037] ③ The digital storage module is communicatively connected to the signal processing module and uses an NVMe interface (Non-Volatile Memory Express), that is, the non-volatile memory host controller interface specification. It can also be replaced with an eMMC (Embedded Multi Media Card) storage or an SATA (Serial Advanced Technology Attachment) interface standard. The digital storage module is used to store the M4 response "three-pulse" digital information and the ciphertext information of the M4 interrogation signal.

[0038] ④ The power supply module. The main function of the power supply module is to convert the input external power supply into the electrical energy required by each module in this M4 response interference device. Among them, the power supply module is used to supply power to the signal processing module and the transceiver module respectively. This power supply module has functions of heat dissipation, current limiting, overvoltage protection, overload protection, anti-surge, spike and power-off protection.

[0039] The technical specifications of this M4 interrogator interference device are as follows: (1) Reception characteristics Receiver center frequency: 1030 MHz ± 0.2 MHz; Receiver sensitivity: -77 dBm ± 3 dB; 3 dB bandwidth: 8 - 10 MHz; Dynamic range: ≥ 50 dB.

[0040] (2) Transmission characteristics Center frequency: 1090 MHz ± 1 MHz; Port transmission power: 57 dBm ± 3 dB (250 W - 1000 W); Modulation method: ASK; Maximum duty cycle: not greater than 2%; Pulse sequence flatness: ≤ 2.0 dB, Pulse top flatness: ≤ 1.0 dB, M4; Pulse rise time: ≤ 0.1 μs, Pulse fall time: ≤ 0.2 μs, M4; Pulse width: 0.5 μs ± 0.1 μs, M4; Pulse interval error: ± 0.1 μs, M4.

[0041] (3) Decoding and encoding capabilities are as follows: 1) Interference mode: M4 response interference; 2) Sidelobe suppression: In the receiver dynamic range, when the M4 mode: P5 ≥ P4, the device determines it as a sidelobe and does not perform decoding; 3) Response interference rate limit: 1200 ± 120 times / second; 4) 16-group response interference delay: 202 μs + random response delay (μs).

[0042] The interference device is externally connected to a deciphering system and an external control system through the signal processing module. According to the command of the external control system, the ciphertext information of the M4 interrogation signal obtained and stored by this interception is sent to the deciphering system. Specifically, the power supply module is supplied with DC +28V power by an external power supply; the signal processing module realizes "interactive" communication of commands or data with the external control system through an RS422 interface, and the signal processing module is communicatively connected to the next-level deciphering system through an NVMe interface and transmits the ciphertext information of the intercepted M4 interrogation signal.

[0043] The working principle of the deception interference device in this embodiment is as follows: After being powered on, the power supply module converts the external power supply into the DC power required by each internal module. When an intercepted signal is input from the antenna, the 1030MHz interrogation signal from the antenna enters the transceiver module through the circulator. The receiving unit of the transceiver module is responsible for converting the radio frequency signal into an intermediate frequency signal and a video detection signal; the intermediate frequency processing unit of the signal processing module sends the ASK demodulation signal to the coding and decoding unit for processing; the coding and decoding unit processes the video detection signal and the demodulated output signal, and forms a corresponding response coding signal according to the interrogation type and control data and sends it to the transmitting unit of the transceiver module; the transmitting unit is responsible for modulating, amplifying, etc. the response coding signal sent by the signal processing module. Finally, it is transmitted through the antenna centered at 1090MHz ± 1MHz.

[0044] The deception interference device of this embodiment communicates with the external control system through an RS422 interface, and can also be replaced by an RS 485 serial communication interface. It transmits the intercepted M4 ciphertext information to the deciphering system through an NVMe interface and can be used as a ciphertext sample for domestic military deciphering systems.

[0045] The deception interference device of this embodiment can be used both as an active interference device for attacking target drones; and as a device for testing, evaluating, and inspecting the anti-attack and anti-interference performance of the IFF system M4 interrogators developed by domestic manufacturers.

[0046] It should be noted that any process or method description shown in the flowchart or described in other ways herein can be understood as representing a module, segment, or part of code including one or more executable instructions for implementing a specific logical function or process. And the scope of the preferred embodiments of the present application includes additional implementations, where the functions can be executed in a way that is not shown or discussed in sequence, including in a substantially the same way or in the reverse order according to the functions involved, which should be understood by those skilled in the technical field to which the embodiments of the present application belong.

[0047] It should be understood that various parts of the present application can be implemented by hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: discrete logic circuits having logic gate circuits for implementing logic functions on data signals, application specific integrated circuits having appropriate combinational logic gate circuits, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), etc.

[0048] Those of ordinary skill in the art can understand that all or part of the steps carried by the method of implementing the above embodiments can be completed by instructing relevant hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiments.

[0049] In addition, in each embodiment of the present application, each functional unit can be integrated into a processing module, or each unit can exist physically alone, or two or more units can be integrated into one module. The above integrated module can be implemented in the form of hardware or in the form of a software functional module. When the above integrated module is implemented in the form of a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0050] The above-mentioned storage medium can be a read-only memory, a magnetic disk, an optical disk, etc.

[0051] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. A deception jamming method based on the M4 interrogator of the IFF system, characterized in that: The deception jamming methods include: S1: In the L band, 1030Mhz±0.2Mhz is used as the receiving center frequency to detect and receive the friend-or-foe identification signal; S2: According to the Mark XII standard requirements, determine whether the received IFF signal is an M4 interrogation signal and generate a "correlation peak" signal; S3: Based on the rising edge of the synchronization pulse P4 in the M4 interrogation signal as the timing reference, the M4 response "three-pulse" digital information is encoded and generated, and the ciphertext information of the received M4 interrogation signal is extracted according to the "correlation peak" signal; S4: stores the ciphertext information of the M4 response "three pulses" digital information and the M4 inquiry signal; S5: Generate a fixed response delay time of the M4 inquiry signal according to the timing information, and sequentially generate 16 groups of random response delay code marker pulse signals corresponding to the fixed response delay time according to the random response delay code generation mechanism; S6: According to the marker pulse signals of the 16 groups of random response delay codes, the stored M4 response "three pulses" digital information is read out and 16 groups of interference response signals corresponding to the M4 interrogation signal received this time are generated.

2. The deception jamming method based on the friend-or-foe identification system M4 interrogator according to claim 1 is characterized in that: In S1, the method for detecting and receiving the friend-or-foe identification signal is: S101: Detect and receive radio frequency signals with a center frequency of 1030 MHz ± 0.2 MHz in the L band; S102: The RF signal is filtered and amplified and then mixed with a 1170 MHz local oscillator signal to generate a 140 MHz intermediate frequency signal; S103: Perform ASK demodulation on the 140Mhz intermediate frequency signal to obtain a demodulated signal; S104: Perform amplitude processing on the demodulated signal to obtain corresponding amplitude information.

3. The deception jamming method based on the friend-or-foe identification system M4 interrogator according to claim 2 is characterized in that: In said S2, the specific method is: S201: collecting the width and amplitude information of the synchronization pulses P1, P2, P3, P4, and P5 in the friend-or-foe identification signal in real time; S202: comparing with the waveform timing characteristics of the M4 interrogation signal; S203: Determine whether it is an M4 interrogation signal, if so, proceed to the next step; if not, discard the friend-or-foe identification signal; S204: Using the rising edge of the synchronization pulse P1 in the M4 interrogation signal as a timing reference, a "correlation peak" signal is generated at 10µs, which serves as the starting position for the subsequent extraction of the ciphertext information of the M4 interrogation signal.

4. The deception jamming method based on the friend-or-foe identification system M4 interrogator according to claim 1 is characterized in that: In the S3, the M4 response "three-pulse" digital information is encoded and generated according to the M4 response "three-pulse" waveform characteristics specified in the Mark XII standard; and the ciphertext information of the M4 interrogation signal is collected at the rising edge of the "correlation peak" signal according to the waveform timing characteristics of the M4 interrogation signal specified in the Mark XII standard.

5. The deception jamming method based on the friend-or-foe identification system M4 interrogator according to claim 4 is characterized in that: The M4 response "three-pulse" digital information is a baseband code element composed of 0 and 1; the ciphertext information of the M4 inquiry signal is an information unit composed of 0 and 1.

6. The deception jamming method based on the friend-or-foe identification system M4 interrogator according to claim 1 is characterized in that: In S5, the random response delay code generation mechanism includes: S501: According to the MARK XII standard, the rising edge of the synchronization pulse P4 in the M4 interrogation signal is used as the timing reference; S502: According to the occurrence time of the i-th group of interference response signals t=202+5.25×Nμs±1.25μs (N=0,1,2...15); generate the i-th group of random response delay code j of the marker pulse signal Pj, wherein i=1,2,3...16; N=j=i-1.

7. The deception jamming method based on the friend-or-foe identification system M4 interrogator according to claim 6 is characterized in that: The S6 includes: S601: extract the rising edges of the marker pulse signals of 16 groups of random response delay codes in sequence and use them as valid read signals to read out the M4 response "three pulses" digital information in sequence; S602: Process the "three-pulse" digital information of M4 response and output an ASK demodulated signal of 1090Mhz±1MHz; S603: After amplifying the ASK demodulated signal, 16 groups of interference response signals are generated in sequence and transmitted.

8. The deception jamming method based on the friend-or-foe identification system M4 interrogator according to claim 1 is characterized in that: The deception interference method also includes: sending the ciphertext information of the M4 interrogation signal acquired and stored in this interception to a decryption system.

9. A deception jamming device based on the M4 interrogator of the IFF system, characterized in that: The deception jammer includes: A signal processing module, the signal processing module is used to run the deception interference method based on the friend-or-foe identification system M4 interrogator according to any one of claims 1 to 8; A transceiver module in communication with the signal processing module, the transceiver module being connected to an antenna and used to detect and receive the M4 interrogation signal and transmit the M4 response signal; A digital storage module in communication with the signal processing module, the digital storage module being used to store the M4 response "three pulses" digital information and the ciphertext information of the M4 interrogation signal; A power supply module, wherein the power supply module is used to supply power to the signal processing module and the transceiver module respectively.

10. The deception jamming device based on the friend-or-foe identification system M4 interrogator according to claim 9 is characterized in that: The signal processing module is communicatively connected with the decryption system and the external control system, and according to the command of the external control system, the ciphertext information of the M4 interrogation signal acquired and stored in this interception is sent to the decryption system.

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