A deception jamming method and device based on the M4 interrogator of the friend-or-foe identification system

Abstract

The present invention discloses a deception jamming method and device based on an M4 interrogator of an identification friend or foe (IFF) system, belonging to the technical field of radar countermeasures. The deception jamming method comprises: starting timing after detecting a rising edge of a synchronization pulse P4 in an M4 interrogation signal; encoding and generating an M4 response "three-pulse" signal according to the characteristics of the M4 interrogation signal after waveform feature matching; transmitting all possible jamming response signals according to the generation time of the M4 response signal to form effective "deception" jamming; and converting the received M4 interrogation signal into digital information for storage, thereby solving the problem of being unable to effectively jam an enemy M4 interrogator due to being unable to obtain a "response delay code" in ciphertext information. The method can effectively counter an enemy M4 interrogator in a battlefield environment, thereby achieving the purpose of deception jamming; and evaluating the anti-jamming capability and active jamming capability of one's own IFF system according to the working mechanism of the IFF M4 system in the Mark XII standard.

Description

Technical Field

[0001] The present invention belongs to the technical field of radar countermeasures, and in particular relates to a deception jamming method and device based on an M4 interrogator of an identification friend or foe system. Background Art

[0002] The IFF system identifies enemy and friend attributes of targets detected and detected by radar, forming a comprehensive battlefield situation and providing accurate intelligence information to military command. It is also a key combat equipment supporting weapon systems. IFF countermeasures involve detecting, identifying, and locating enemy IFF system signals, and then directing jammers to attack, disrupt, or destroy the enemy IFF system.

[0003] The primary technical feature of the M4 system's friend-or-foe identification is the encryption of interrogation messages in the uplink 1030MHz band to produce ciphertext. This ciphertext contains a random response delay code, specified by the interrogator and carried in the ciphertext. The transponder receives and decrypts the ciphertext, extracts the random response delay code, and generates a corresponding response signal in accordance with this specification. For non-friendly or enemy M4 transponders, the inability to decrypt the ciphertext prevents the "specified" random response delay code from being retrieved, resulting in an erroneous response signal. After receiving and processing the response signal in the downlink 1090MHz band, the M4 interrogator compares the arrival time of the response signal to see if it meets the "specified" time for generating the response signal. If so, it is identified as friendly or friendly. Otherwise, it is identified as "enemy" and the identification information is reported to the intelligence command center.

[0004] The M4 system is a Mark XII-compliant IFF system. As the primary device for identifying enemy and foe attributes in combat, traditional noise suppression jamming requires high-power transmission capabilities to achieve effective jamming. This presents significant engineering challenges. Furthermore, high-power transmissions easily expose the jammer's location (the jammer's source), making it vulnerable to enemy detection and attack, significantly reducing battlefield survivability.

[0005] Based on the above, it is urgent to develop a jamming strategy for the M4 interrogator of the friend-or-foe identification system to make it generate all possible "false" M4 reply signals, so as to effectively reduce the combat effectiveness of the enemy's M4 interrogator and win battlefield survival time for one's side. Summary of the Invention

[0006] In view of this, and in order to solve the above-mentioned problems existing in the prior art, the purpose of the present invention is to provide a deception jamming method and apparatus based on the M4 interrogator of the IFF system, so as to solve the problem that the enemy M4 interrogator cannot be effectively jammed 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 jamming; at the same time, according to the working mechanism of the M4 IFF system in the Mark XII standard, a battlefield electromagnetic environment can be constructed to evaluate the anti-interference capability and active jamming capability of one's own IFF system.

[0007] The technical solution adopted by the present invention is: a deception jamming method based on the M4 interrogator of the friend-or-foe identification system, the deception jamming method comprising:

[0008] S1: Receives friend-or-foe identification signals at 1030 MHz ± 0.2 MHz in the L band.

[0009] S2: Determines whether the received IFF signal is an M4 interrogation signal and generates a "correlation peak" signal according to the Mark XII standard.

[0010] 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 based on the "correlation peak" signal;

[0011] S4: stores the ciphertext information of M4's response "three pulses" and M4's interrogation signal;

[0012] S5: Generate a fixed response delay time for the M4 interrogation signal based on the timing information, and sequentially generate 16 groups of random response delay code marker pulse signals corresponding to the fixed response delay time based on a random response delay code generation mechanism;

[0013] S6: According to the marker pulse signals of the 16 groups of random response delay codes, the stored M4 response "three-pulse" digital information is read out and 16 groups of interference response signals corresponding to the M4 interrogation signal received this time are generated.

[0014] Furthermore, in S1, the method for detecting and receiving the friend-or-foe identification signal is:

[0015] S101: Detects and receives radio frequency signals with a center frequency of 1030 MHz ± 0.2 MHz in the L band;

[0016] S102: The RF signal is filtered and amplified and then mixed with the 1170 MHz local oscillator signal to generate a 140 MHz intermediate frequency signal;

[0017] S103: Perform ASK demodulation on the 140 MHz intermediate frequency signal to obtain a demodulated signal;

[0018] S104: Perform amplitude processing on the demodulated signal to obtain corresponding amplitude information.

[0019] Furthermore, in said S2, the specific method is:

[0020] S201: Real-time acquisition of width and amplitude information of synchronization pulses P1, P2, P3, P4, and P5 in the friend-or-foe identification signal;

[0021] S202: Compare the waveform timing characteristics of the M4 interrogation signal with those of the M4 interrogation signal;

[0022] 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.

[0023] 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 subsequent extraction of the ciphertext information of the M4 interrogation signal.

[0024] 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 on 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.

[0025] 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.

[0026] Furthermore, in S5, the random response delay code generation mechanism includes:

[0027] 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;

[0028] S502: Based on the occurrence time of the i-th group interference response signal t=202+5.25×Nμs±1.25μs (N=0,1,2...15), generate the i-th group random response delay code j marker pulse signal Pj, where i=1,2,3...16; N=j=i-1.

[0029] Furthermore, the step S6 includes:

[0030] S601: Sequentially extract the rising edges of the marker pulse signals of 16 groups of random response delay codes and use them as valid read signals to sequentially read out the M4 response "three-pulse" digital information;

[0031] S602: Process the "three-pulse" digital information of M4's response and output an ASK demodulated signal of 1090 MHz ± 1 MHz;

[0032] S603: After amplifying the ASK demodulated signal, 16 groups of interference response signals are generated in sequence and transmitted.

[0033] Furthermore, the deception interference method further includes: sending the encrypted information of the M4 interrogation signal acquired and stored in this interception to the decryption system.

[0034] The present invention also discloses a deception jamming device based on an M4 interrogator of an identification friend or foe system, the deception jamming device comprising:

[0035] A signal processing module, the signal processing module being used to execute the above-mentioned deception jamming method based on the M4 interrogator of the IFF system;

[0036] a transceiver module in communication with the signal processing module, the transceiver module being connected to an antenna and configured to receive an M4 interrogation signal and transmit an M4 response signal;

[0037] A digital storage module in communication with the signal processing module, the digital storage module being used to store the M4 response "three-pulse" digital information and the ciphertext information of the M4 interrogation signal;

[0038] A power supply module, which is used to supply power to the signal processing module and the transceiver module respectively;

[0039] Furthermore, the signal processing module is communicatively connected to a decryption system and an external control system, and sends the encrypted information of the M4 interrogation signal acquired and stored in this interception to the decryption system according to a command of the external control system.

[0040] The beneficial effects of the present invention are:

[0041] 1. The present invention provides a deceptive jamming method for the M4 interrogator of the IFF system. Its jamming method is classified as "deceptive jamming." Based on the detection, identification, and reception of the M4 interrogation signal, a false M4 reply signal corresponding to the "current" interrogation signal is generated. Furthermore, the waveform characteristics of the false M4 reply signal conform to the Mark XII standard, and the reply time covers all 16 possible scenarios. This makes it difficult for the enemy interrogator to distinguish between true and false, causing "target" confusion. This effectively reduces the combat effectiveness of the enemy M4 interrogator, preventing enemy weapon platforms from acquiring "real" and "valid" friendly targets in real time, thus wasting combat opportunities.

[0042] 2. Compared to the active, high-power "noise suppression" jamming method, the deception jamming device based on the M4 interrogator of the IFF system provided by this invention offers full-coverage "deception jamming." Each jamming operation is triggered by an interrogation by the enemy's M4 interrogator, resulting in better concealment. This reduces the probability of exposing the aerial jamming platform and enhances the jamming device's battlefield survivability.

[0043] 3. The deception jamming device based on the M4 interrogator of the IFF system provided by this invention adopts a modular hardware design, is compact, and has wide platform applicability. It has reserved external control and power supply interfaces and can be integrated into airborne electronic equipment such as reconnaissance and jamming equipment.

[0044] 4. The deception and jamming method and device based on the IFF M4 interrogator provided by the present invention are proposed based on the working mechanism of the IFF M4 system and fully comply with the requirements of the Mark XII standard. On the one hand, they can construct a simulated Western-style M4 electromagnetic combat environment to verify and improve the capabilities of domestic collection equipment in electromagnetic combat environments, and verify the working efficiency of domestic radar equipment in complex electromagnetic environments. On the other hand, they can be used to test the anti-interference performance of domestic IFF equipment, especially to test and evaluate the anti-interference capability of domestic IFF M4 interrogator equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a logic flow chart of the deception jamming method based on the M4 interrogator of the IFF system provided by the present invention;

[0046] Figure 2 This is a schematic diagram of the ASK demodulation principle of the M4 interrogation signal in the deception jamming method based on the M4 interrogator of the IFF system provided by the present invention;

[0047] Figure 3 Schematic diagram of waveform characteristics of the M4 interrogation signal in the deception jamming method based on the M4 interrogator of the identification friend or foe system provided by the present invention;

[0048] Figure 4 Schematic diagram of waveform characteristics of the M4 response "three-pulse" signal in the deception jamming method based on the M4 interrogator of the identification friend or foe system provided by the present invention;

[0049] Figure 5 This is a time slot diagram of generating 16 groups of M4 jamming response signals in the deception jamming method based on the M4 interrogator of the identification friend or foe system provided by the present invention;

[0050] Figure 6 This is a diagram of the internal module architecture of the deception jamming device based on the M4 interrogator of the IFF system provided by the present invention;

[0051] Figure 7 This is an architectural diagram of the signal processing module in the deception jamming device based on the M4 interrogator of the friend-or-foe identification system provided by the present invention. DETAILED DESCRIPTION

[0052] The embodiments of the present application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar modules or modules with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application. On the contrary, the embodiments of the present application include all changes, modifications, and equivalents that fall within the spirit and scope of the appended claims.

[0053] Example 1

[0054] Based on the operating mechanism, principles, and signal characteristics of the M4 IFF system in the MARK XII standard, this embodiment discloses a deceptive jamming method based on the M4 interrogator of the IFF system. The encrypted M4 interrogation signal transmitted by the M4 interrogator contains the random response delay code "agreed" for the M4 downlink 1090 MHz response. The M4 response signal is a fixed "three-pulse" response signal, and the timing of the response signal transmitted by the transponder is determined by both the fixed response delay and the random response delay. The fixed response delay is 202 μs, and the random response delay is determined by the 4-bit random response delay code in the encrypted information. Therefore, the timing of each M4 response signal generation is randomly variable, with 16 possible transition times (determined by the 4-bit random response delay code, according to the MARK XII standard).

[0055] On the other hand, since the M4 reply signal waveform consists of three fixed pulses, with a single pulse width of 0.45μs ± 0.1μs, the three pulses of each M4 reply signal last for 5.25μs. The actual time of each M4 reply signal is t = 202 + 5.25 × Nμs (N = 0, 1, 2, ..., 15). Based on the hopping pattern of the M4 random reply timing, for each M4 interrogation signal, a jamming reply signal with 16 possible scenarios is transmitted in response. This ensures that the enemy M4 interrogator can obtain one of the 16 possible scenarios that can "correctly decode" the information and obtain "stable range correlation" each time, keeping the jammed M4 interrogator in a "busy state" state. This achieves the effects of "deceptive jamming" and "blocking jamming," effectively reducing the enemy M4 interrogator's combat effectiveness.

[0056] Specifically, such as Figure 1 As shown, the deception interference method includes:

[0057] S1: Receive an IFF signal in the L-band at a center frequency of 1030 MHz ± 0.2 MHz. The method for receiving and processing the IFF signal includes:

[0058] S101: Receive radio frequency signals with an L-band center frequency of 1030 MHz ± 0.2 MHz. The received signals must meet the following technical specifications: a 3 dB detectable bandwidth of 8 MHz to 10 MHz, a receive decoding sensitivity (MTL) of -77 dBm ± 3 dB, and a receive dynamic range of ≥ 50 dB.

[0059] S102: The RF signal is filtered and amplified and then mixed with the 1170 MHz local oscillator signal to generate a 140 MHz intermediate frequency signal;

[0060] S103: If Figure 2 As shown in the figure, the intermediate frequency signal is sent to the FPGA for digital demodulation after ADC data acquisition. The signal is first digitally down-converted (DDC) using the correlation demodulation method, and then ASK demodulation is completed by taking the square root of the signal.

[0061] 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.

[0062] S2: According to the Mark XII standard requirements, determine whether the detected friend-or-foe identification signal is an M4 interrogation signal, and generate a "correlation peak" signal for the M4 interrogation signal. Figure 3 As shown in the figure, the M4 interrogation signal consists of four fixed synchronization header pulses (P1-P4), one sidelobe suppression pulse (P5), and 32 randomly hopping encrypted information pulses (P6-P37). A transponder loaded with the same key can parse the correct key information from these 32 randomly hopping encrypted information pulses and issue an identification response. The M4 response signal has a fixed three-pulse pattern, but the response delay also randomly changes depending on the 32 bits of random information.

[0063] 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; the pulse rising edge is ≤ 0.1µs, and the falling edge is ≤ 0.2µs.

[0064] The specific method of this S2 step is:

[0065] S201: Real-time acquisition of the width and amplitude information of the synchronization pulses P1, P2, P3, P4, and P5 in the detected friend-or-foe identification signal;

[0066] S202: Compare the waveform timing characteristics of the M4 interrogation signal with those specified in the Mark XII standard;

[0067] 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:

[0068] For a detection signal that meets the requirements of a total single pulse width of 2µs, a high-level "1" width of 0.5±0.1µs within a single pulse, a pulse rising edge of ≤ 0.1µs, a falling edge of ≤ 0.2µs, a 2µs interval between adjacent pulse rising edges, 6µs from the rising edge of pulse P1 to the rising edge of pulse P4, and 8µs from the rising edge of pulse P1 to the rising edge of pulse P5, if the amplitude of pulse P5 is less than the amplitude of pulse light P4, it is confirmed to be an M4 interrogation signal; otherwise, it is considered a sidelobe signal and is suppressed, and the frame of signal is discarded.

[0069] S204: Using the rising edge of the synchronization pulse P1 in the M4 interrogation signal as the 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. At the same time, the timing pulses P6 to P37, the 32 pulses of interrogation ciphertext information data, have a total width of 64µs, and each pulse has a width of 2µs.

[0070] 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 based on the "correlation peak" signal. Specifically, based on the waveform characteristics of the M4 response "three-pulse" specified in the MarkXII standard, the M4 response "three-pulse" digital information is encoded and generated; wherein, Figure 4 As shown in the figure, the waveform characteristics of the M4 response "three-pulse" signal are as follows: pulse width: 0.5±0.1µs; adjacent pulse interval: 1.75±0.1µs; pulse rising edge: ≤ 0.1µs, falling edge: ≤ 0.2µs;

[0071] According to the waveform timing characteristics of the M4 interrogation signal specified in the Mark XII standard, the ciphertext information of the M4 interrogation signal is collected at the rising edge of the "correlation peak" signal.

[0072] S4: Stores the M4 response "three-pulse" digital information. The M4 response "three-pulse" digital information is a baseband code element composed of 0s and 1s. After being converted into a data packet, it is written to the digital storage module via the NVMe bus according to the transmission protocol with the digital storage module for storage. The write speed can reach 5000MB / s. At the same time, the ciphertext information of the M4 interrogation signal is stored. The ciphertext information of the M4 interrogation signal is an information unit composed of 0s and 1s. After being converted into a data packet, it is written to the corresponding address of the digital storage module via the NVMe bus according to the transmission protocol with the digital storage module for storage.

[0073] S5: Generate a fixed response delay time for the M4 interrogation signal based on the timing information, and sequentially generate 16 groups of random response delay code marker pulse signals corresponding to the fixed response delay time based on a random response delay code generation mechanism. In S5, the random response delay code generation mechanism includes:

[0074] 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. Specifically, the internal 80MHz clock signal is used as the main processing clock, corresponding to a period of 12.5ns, and the timing circuit is designed.

[0075] S502: Based on the occurrence time of the i-th group of interference response signals, t = 202 + 5.25 × N μs ± 1.25 μs (N = 0, 1, 2 ... 15), generate the i-th group of random response delay code j as the marker pulse signal Pj, where i = 1, 2, 3 ... 16 and N = j = i - 1. They are as follows:

[0076] The occurrence 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 generated as the marker pulse signal P0 with a width of 25ns.

[0077] The occurrence 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 generated as a marker pulse signal P1 with a width of 25ns.

[0078] The occurrence 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 a marker pulse signal P15 with a width of 25ns.

[0079] S6: Based on the marker pulse signals of the 16 random response delay codes, the stored M4 response "three-pulse" digital information is read out and 16 interference response signals corresponding to the M4 interrogation signal received this time are generated, which specifically includes:

[0080] S601: Sequentially extract the rising edges of the marker pulse signals of 16 groups of random response delay codes and use them as valid read signals to sequentially read out the M4 response "three-pulse" digital information;

[0081] S602: Process the "three-pulse" digital information of M4's response and output an ASK demodulated signal of 1090 MHz ± 1 MHz;

[0082] S603: After amplifying the ASK demodulated signal, 16 groups of interference response signals are generated in sequence and transmitted.

[0083] like Figure 5 As shown, 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 is emitted; when the timing reaches 202μs+5.25×1±1.25μs, the second group of interference response signals is emitted; ...; when the timing reaches 202μs+5.25×15±1.25μs, the 16th group of interference response signals is generated in sequence.

[0084] S7: Perform self-tests on the friend-or-foe (IFF) system M4 interrogator at predetermined intervals and sends self-test information to the external control system. Specifically:

[0085] S701: Real-time collection of status information of each unit module in the interference host to form self-test information of the entire machine;

[0086] S702: Report the self-test information to the external control system according to the reporting period (usually 1 second). The reporting period of the self-test information may also be changed according to a command from the external control system.

[0087] S8: According to the command of the external control system, the encrypted information of the M4 interrogation signal acquired and stored in this interception is sent to the decryption system. The encrypted information of the M4 interrogation signal is provided to the friendly intelligence system and used by the lower-level decryption system. By continuously intercepting and accumulating more samples, the conditions are created for further decryption of the enemy's interrogation encryption algorithm and key. Specifically:

[0088] S801: Reading the digital storage module in response to a command from the external control system to obtain the ciphertext information of the M4 interrogation signal stored after detection;

[0089] S802: The ciphertext information of the M4 interrogation signal is used as a decryption sample and sent to the decryption system via the NVMe high-speed bus according to the communication protocol between the next-level decryption system.

[0090] The deception jamming method of this embodiment, based on the M4 "interrogation-reply" mechanism for friend-or-foe identification in the Mark XII standard, proposes a method for detecting and judging M4 interrogation signals. Based on the M4 reply signal generation mechanism, a calculation method for fixed and random reply delay times is proposed: M4 reply signal generation time = fixed reply delay time (202 μs) + random reply delay time (determined by a random reply delay code). The method also provides the time it takes to generate a "false" reply signal. Based on the 16 reply signals corresponding to a single M4 interrogation, full jamming coverage is achieved for all 16 reply signals. This ensures that the enemy M4 interrogator can always find the "correct" M4 reply signal among the 16 reply signals, achieving "stable range correlation" and keeping the jammed M4 interrogator in a "busy state." This reduces the enemy M4 interrogator's combat effectiveness, achieving the purpose of deception jamming. Furthermore, the method offers superior concealment, reduces the probability of exposing the airborne jamming host, and enhances the jamming device's battlefield survivability.

[0091] Example 2

[0092] 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 jamming device includes:

[0093] ① Signal processing module, the signal processing module is used to run the deception jamming method logic based on the friend-or-foe identification system M4 interrogator in the above embodiment 1. Figure 7As shown, the signal processing module mainly uses ARM and FPGA as the signal processing core, FPGA realizes encoding and decoding signal processing, ARM realizes protocol analysis and data packaging, and the drive and interface circuit realizes electrical matching and internal and external signal isolation. The FPGA and ARM transmit addresses, data and commands, the FPGA receives the 1030Mhz frequency band signal after AD conversion, and the FPGA and the digital storage module transmit information through the NVMe protocol interface; the ARM is connected to the EPROM memory, and the ARM transmits the self-test status information to the external control system through the reset circuit, and receives the switch and response information through the 422 interface circuit. This signal processing module mainly realizes the decoding and judgment of M4 interrogation signals, the encoding of response interference signals, the input and output suppression interface control function, the communication function with the external control system through the RS422 interface, and the 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 500 I / Os. Xilinx Altera manufacturers or other similar chips can also be used as substitutes; the embedded processor ARM model used is the STM32F746VGT6 chip, which can also be replaced by other similar chips.

[0094] ② Transceiver module: The transceiver module is communicatively connected to the signal processing module. The circulator in the transceiver module is connected to an external antenna via a radio frequency interface. The antenna is used to detect and receive M4 interrogation signals and transmit M4 response signals. The antenna realizes that the M4 interrogation signal receiving operating frequency band is 1030MHz±3MHz, and the transmitting operating 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 a frequency of 1090MHz. After multi-stage power amplification, the required power value is obtained. According to the external response interference instruction, the transmitting unit is transmitted from the antenna via the radio frequency interface unit. The radio frequency interface unit is based on DDS and contains a 3.5GHz clock. It can more accurately and precisely control the DDS, ensuring that the single pulse of the M4 interference response signal meets 0.50μs±0.1μs, the pulse rise time is ≤100ns, and the pulse fall time is ≤200ns.

[0095] The receiving unit is used to obtain an intermediate frequency signal with a certain amplitude and a video detection signal after a series of processing such as filtering, amplification, down-conversion, intermediate frequency amplification and filtering, and video detection on the radio frequency input signal.

[0096] ③ Digital storage module: The digital storage module is communicatively connected to the signal processing module and uses the NVMe interface (Non-Volatile Memory Express), which is a non-volatile memory host controller interface specification. It can also be replaced by eMMC (Embedded Multi Media Card) storage or SATA (Serial Advanced Technology Attachment) interface standards. The digital storage module is used to store the M4 response "three-pulse" digital information and the ciphertext information of the M4 inquiry signal.

[0097] ④ 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 power the signal processing module and the transceiver module respectively. This power supply module has heat dissipation, current limiting, overvoltage, overload protection, anti-surge, spike and power-off protection functions.

[0098] The technical specifications of the M4 interrogator jammer are as follows:

[0099] (1) Receiving characteristics

[0100] Receiver center frequency: 1030MHz±0.2MHz; Receiver sensitivity: -77dBm±3dB; 3dB bandwidth: 8~10 MHz; Dynamic range: ≥50dB.

[0101] (2) Emission characteristics

[0102] Center frequency: 1090MHz±1MHz; Port transmit power: 57dBm±3dB (250W~1000W); Modulation mode: ASK; Maximum duty cycle: no more than 2%; Pulse sequence unevenness: ≤2.0dB, pulse top unevenness: ≤1.0dB, M4; Pulse rise time: ≤0.1μs, pulse fall time: ≤0.2μs, M4; Pulse width: 0.5μs±0.1μs, M4; Pulse interval error: ±0.1μs, M4.

[0103] (3) Decoding and encoding capabilities are as follows:

[0104] 1) Interference mode: M4 response interference; 2) Sidelobe suppression: Within the receiver dynamic range, when M4 mode: P5 ≥ P4, the device identifies it as a sidelobe and does not decode; 3) Response interference rate limit: 1200 ± 120 times / second; 4) 16-group response interference delay: 202μs + random response delay (μs).

[0105] This jamming device is externally connected to a decryption system and an external control system via the signal processing module. Based on commands from the external control system, the device transmits the encrypted information of the intercepted and stored M4 interrogation signal to the decryption system. Specifically, the power module is powered by a +28V DC external power supply. The signal processing module interactively communicates commands or data with the external control system via an RS422 interface. Furthermore, the signal processing module communicates with the next-level decryption system via an NVMe interface, transmitting the encrypted information of the intercepted M4 interrogation signal.

[0106] The working principle of the deception jamming device in this embodiment is as follows:

[0107] After power is turned on, the power module converts the external power supply into the DC power required by each internal module. When a detection 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 RF signal into an intermediate frequency signal and a video detection signal; the intermediate frequency processing unit of the signal processing module sends the ASK demodulated signal to the encoding and decoding unit for processing; the encoding and decoding unit processes the video detection signal and the demodulated output signal, and forms a corresponding response code signal according to the interrogation type and control data, which is sent to the transmitting unit of the transceiver module; the transmitting unit is responsible for modulating, amplifying and other processing of the response code signal sent by the signal processing module, and finally, transmitting it through the antenna with 1090MHz±1MHz as the center.

[0108] The deception jamming device of this embodiment communicates with the external control system through the RS422 interface, which can also be replaced by the RS 485 serial communication interface. The M4 ciphertext information detected and received is transmitted to the decryption system through the NVMe interface, which can be used as a ciphertext sample for the domestic military decryption system.

[0109] The deception jamming device of this embodiment can be used as an active jamming device for attacking a target drone; it can also be used to test, evaluate, and inspect the anti-attack and anti-jamming performance of the M4 interrogator of the friend-or-foe identification system developed by domestic manufacturers.

[0110] It should be noted that any process or method description in the flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a specific logical function or process, and that the scope of the preferred embodiments of the present application includes alternative implementations in which the functions may not be performed in the order shown or discussed, including performing the functions in substantially the same manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present application belong.

[0111] It should be understood that various parts of the present application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used to implement: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0112] Those skilled in the art will understand that all or part of the steps in the method of the above embodiment can be completed by instructing related 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 embodiment.

[0113] In addition, the functional units in the various embodiments of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into a module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0114] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0115] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify 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 method includes: S1: Receive IFF signals at 1030 MHz ± 0.2 MHz in the L band. The method for receiving IFF signals is as follows: S101: Detects and receives 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 the 1170 MHz local oscillator signal to generate a 140 MHz intermediate frequency signal; S103: Perform ASK demodulation on the 140 MHz intermediate frequency signal to obtain a demodulated signal; S104: Perform amplitude processing on the demodulated signal to obtain corresponding amplitude information; S2: According to the Mark XII standard, determine whether the received IFF signal is an M4 interrogation signal and generate a "correlation peak" signal; the specific method is as follows: S201: Real-time acquisition of width and amplitude information of synchronization pulses P1, P2, P3, P4, and P5 in the friend-or-foe identification signal; S202: Compare the waveform timing characteristics of the M4 interrogation signal with those 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 subsequent extraction of the ciphertext information of the M4 interrogation 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 based on the "correlation peak" signal; S4: stores the ciphertext information of M4's response "three pulses" and M4's interrogation signal; S5: Generate a fixed response delay time for the M4 interrogation signal based on the timing information, and sequentially generate 16 groups of random response delay code marker pulse signals corresponding to the fixed response delay time based on a random response delay code generation mechanism; 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: Based on the occurrence time of the i-th group interference response signal t=202+5.25×Nμs±1.25μs, where N=0,1,2...15; generate the i-th group random response delay code j marker pulse signal Pj, where i=1,2,3...16; N=j=i-1; S6: Based on the marker pulse signals of the 16 groups of random response delay codes, the stored M4 response "three-pulse" 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 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 on 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.

3. The deception jamming method based on the friend-or-foe identification system M4 interrogator according to claim 2 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.

4. The deception jamming method based on the friend-or-foe identification system M4 interrogator according to claim 1 is characterized in that: Said S6 includes: S601: Sequentially extract the rising edges of the marker pulse signals of 16 groups of random response delay codes and use them as valid read signals to sequentially read out the M4 response "three pulses" digital information; S602: Process the "three-pulse" digital information of M4's 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.

5. 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 further includes: sending the encrypted information of the M4 interrogation signal acquired and stored in this interception to a decryption system.

6. A deception jamming device based on the M4 interrogator of the IFF system, characterized in that: The deception jamming device includes: A signal processing module, the signal processing module being configured to execute the deception jamming method based on the friend-or-foe identification system M4 interrogator according to any one of claims 1 to 5; a transceiver module in communication with the signal processing module, the transceiver module being connected to an antenna and configured to receive an M4 interrogation signal and transmit an 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-pulse" digital information and the ciphertext information of the M4 interrogation signal; A power supply module is used to supply power to the signal processing module and the transceiver module respectively.

7. The deception jamming device based on the friend-or-foe identification system M4 interrogator according to claim 6 is characterized in that: The signal processing module is communicatively connected to the decryption system and the external control system, and sends the ciphertext information of the M4 interrogation signal acquired and stored in this interception to the decryption system according to the command of the external control system.

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