Radar non-cooperative interference cancellation device and method

Abstract

This application belongs to the field of interference protection and specifically discloses a radar non-cooperative interference cancellation device and method. The device includes: a sampling antenna module for sampling interference signals in the radar space; a switch matrix module for selecting the signals received by M sampling antenna units and sending them to the sampling channel module; a sampling channel module for converting the received M sampling signals to an intermediate frequency; an analog-to-digital conversion module for digitizing the interference sampling intermediate frequency signal and the radar receiving intermediate frequency signal and sending them to the interference perception module and signal processing module; an interference perception module for determining whether there is interference in the radar receiving signal; a signal processing module for performing interference cancellation processing on the signal of the radar receiving link; and a channel calibration module for performing full-link amplitude and phase calibration on the M sampling channels. Through this application, a dynamic closed loop of interference perception, decision-making and behavior is realized, solving the non-cooperative interference problem faced by radar.

Description

Technical Field

[0001] The present application relates to the field of interference protection, and more specifically, to a radar non-cooperative interference cancellation device and method. Background Art

[0002] Electromagnetic interference (EMI) protection is essential for modern information technology equipment operating in complex electromagnetic environments. Radar, a key piece of information technology, can severely degrade its detection and perception performance in complex modern electromagnetic environments due to intentional or unintentional non-cooperative EMI interference. Traditional non-cooperative EMI protection methods, such as spread frequency hopping and adaptive beamforming, have limited interference suppression effectiveness. Newer interference protection methods, such as waveform anti-interference and waveform diversity array radars, present numerous bottlenecks in their engineering application.

[0003] Traditional spatial adaptive beamforming technologies, such as those using auxiliary antennas, employ adaptive optimization principles like power inversion. Adding auxiliary antenna channels will alter the reception pattern of information equipment, while the use of adaptive beamforming principles will also alter the reception pattern. This can affect useful signals when interference is absent. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the purpose of this application is to provide a radar non-cooperative interference cancellation device and method, which aims to solve the problem that the existing electromagnetic interference protection device will cause changes in the receiving pattern during the interference protection process and affect the useful signal when there is no interference.

[0005] To achieve the above objectives, in a first aspect, the present application provides a radar non-cooperative interference cancellation device, comprising: a sampling antenna module, a switch matrix module, a sampling channel module, a signal processing module, and an interference sensing module;

[0006] The sampling antenna module is used to sample the interference signal of at least one radar; the sampling antenna module includes N sampling antenna units, each sampling antenna unit has an operating frequency band greater than or equal to the operating frequency band of a radar main antenna, and is used to receive the spatial interference signal for sampling;

[0007] The switch matrix module is used to connect to the N sampling antenna units of the sampling antenna module; the switch matrix module includes N channels, and selects signals received by M sampling antenna units to be sent to the sampling channel module; N≥M≥2, where N and M are both positive integers;

[0008] The sampling channel module is used to amplify, filter and convert the received M sampling signals into intermediate frequency signals;

[0009] The interference sensing module is configured to sense whether there is interference in the intermediate frequency signal received by the radar. When interference is determined to be present, the radar's receiving link is disconnected, so that the intermediate frequency signal of the radar receiving link is first input to the signal processing module before being output back; and when no interference is detected, the interference cancellation device is bypassed from the radar receiving link.

[0010] The signal processing module includes a multi-domain joint interference cancellation algorithm unit, which executes a multi-domain joint interference cancellation algorithm based on the characteristic differences between the interference signal and the useful signal in the spatial domain, time domain, frequency domain, energy domain and polarization domain, and is used to cancel the interference signal of the radar receiving link by combining M-channel sampling signals.

[0011] In a possible implementation, a relative distance between the sampling antenna unit and the radar main antenna in azimuth or elevation is greater than half an operating wavelength.

[0012] In one possible implementation, the device further includes: an analog-to-digital conversion module and a digital-to-analog conversion module;

[0013] The analog-to-digital conversion module is connected between the sampling channel module and the signal processing module, and is used to digitize the M-channel sampling signals after frequency conversion and the signal of the radar link and send them to the signal processing module;

[0014] The digital-to-analog conversion module is connected to the output end of the signal processing module and is used to convert the signal processed by the signal processing module into an intermediate frequency analog signal and then play it back to the radar receiving link.

[0015] In a possible implementation, the apparatus further includes: a channel calibration module;

[0016] One end of the channel calibration module is connected to the switch matrix module, and the other end is connected to the digital-to-analog conversion module. When the interference cancellation device is in the calibration mode, the switch matrix module connects the channel calibration module with the sampling channel module; when the interference cancellation device is in the receiving mode, the switch matrix module connects the sampling antenna module with the sampling channel module.

[0017] When the interference cancellation device is in a calibration mode, the channel calibration module inputs a calibration signal to the switch matrix module;

[0018] The sampling channel module converts the frequency of the calibration signal and outputs it to the analog-to-digital conversion module;

[0019] The analog-to-digital conversion module converts the received frequency-converted signal into a digital signal and outputs it to the signal processing module;

[0020] The signal processing module analyzes and processes the received digital signal to complete full-link amplitude and phase calibration of the M channels composed of the switch matrix module, sampling channel module, analog-to-digital conversion module, signal processing module and digital-to-analog conversion module.

[0021] In a possible implementation, the switch matrix module includes: a switch matrix unit;

[0022] The switch matrix module is connected to the channel calibration module and is used to receive a calibration signal input by the channel calibration module.

[0023] In a possible implementation, when the interference cancellation device is in a calibration state, the switch matrix unit disconnects the sampling antenna module from the sampling channel module and injects a calibration signal of the channel calibration module into the sampling channel module.

[0024] In a possible implementation, when the radar non-cooperative interference cancellation device is in a receiving mode, the switch matrix unit disconnects the channel calibration module from the sampling channel module and injects the signal received by the sampling antenna module into the sampling channel module;

[0025] The switch matrix unit selects M sampling antenna units or the receiving signals of M sampling antenna unit ports and sends them to the sampling channel module.

[0026] In a possible implementation, the device further includes: an integrated control module;

[0027] The integrated control module includes: a switch matrix module control unit, a sampling channel module control unit, a signal processing module control unit, an interference perception module control unit, a channel calibration module control unit and a parameter injection unit;

[0028] The switch matrix module control unit is connected to the switch matrix module and is used to control the gating of the switch matrix units in the switch matrix module;

[0029] The sampling channel module control unit is connected to the sampling channel module and is used to control the amplifier gain in the sampling channel module, thereby controlling the total gain of the entire sampling channel module link;

[0030] The signal processing module control unit is connected to the signal processing module and is used to control the parameter settings of the signal processing unit in the signal processing module;

[0031] The interference sensing module control unit is connected to the interference sensing module and is used to control the parameter settings of the interference sensing unit in the interference sensing module;

[0032] The channel calibration module control unit is connected to the channel calibration module and is used to control the parameter settings of the channel calibration unit in the channel calibration module;

[0033] The parameter injection unit is connected to the radar and switch matrix module control unit and the sampling channel module control unit, and is used to receive and analyze the radar transceiver control signal, the side angle signal and the gain control signal, so that the signal processing module complies with the following rules when updating the weight: at the beginning of the radar transmission time slot, the weighted weight remains at the weight of the previous moment until the beginning of the radar reception time slot; from the beginning to the end of the radar reception time slot, the weighted weight is adaptively updated.

[0034] In a second aspect, the present application provides a radar non-cooperative interference cancellation method based on the apparatus provided in the first aspect, comprising the following steps:

[0035] Step S1. When the radar non-cooperative interference cancellation device is powered on or reset, the device automatically enters the channel calibration mode and performs full-link amplitude and phase calibration on the sampling channel consisting of the N-routing switch matrix module, sampling channel module, analog-to-digital conversion module, signal processing module, and digital-to-analog conversion module;

[0036] Step S2. After receiving the calibration completion instruction, the device enters the channel receiving mode, and N sampling antenna units sample at least one radar interference signal; the operating frequency band of each sampling antenna unit is greater than or equal to the operating frequency band of the radar main antenna, and is used to receive and sample the corresponding radar interference signal;

[0037] Step S3. Select M sampling antenna units to send the received signals to the sampling channel module; N ≥ M ≥ 2, where N and M are both positive integers;

[0038] Step S4. Convert the M sampling signals received by the sampling channel module into intermediate frequency signals;

[0039] Step S5. Convert the M-channel sampled intermediate frequency signals and the radar received intermediate frequency signal into digital signals respectively, and perform interference sensing processing;

[0040] Step S6. When interference is detected in the radar receive signal, the radar receive link is disconnected, so that the received signal of the radar link is first input into the signal processing module and combined with the M-channel sampled signals for interference cancellation processing before being replayed back to the radar receive link;

[0041] Step S7: When it is detected that there is no interference in the radar receiving signal, the interference cancellation device is bypassed from the radar receiving link.

[0042] In a possible implementation, a relative distance between the sampling antenna unit and the radar main antenna in azimuth or elevation is greater than half an operating wavelength.

[0043] In a possible implementation, the method further includes:

[0044] Connect one end of the channel calibration module to the switch matrix module and the other end to the digital-to-analog conversion module. When the interference cancellation device is in the calibration mode, connect the channel calibration module to the sampling channel module through the switch matrix module.

[0045] When the interference cancellation device is in calibration mode, the channel calibration module inputs a calibration signal to the switch matrix module, and then outputs the calibration signal to the analog-to-digital conversion module through the sampling channel module. After being converted into a digital signal, it enters the signal processing module for analysis and processing, so as to complete the full-link amplitude and phase calibration of the M channels composed of the switch matrix module, sampling channel module, analog-to-digital conversion module, signal processing module and digital-to-analog conversion module.

[0046] In one possible implementation, a radar interference sampling signal is received in space by a sampling antenna unit and fed into a sampling channel module through a switch matrix module. The signal is then down-converted to an intermediate frequency signal using the same local oscillator as the radar main antenna receiving signal. After passing through an analog-to-digital conversion module, the signal is converted into a digital intermediate frequency signal, which is then fed into an interference sensing module and a signal processing module.

[0047] When the interference sensing module determines that there is no interference, the interference cancellation device is bypassed through the bypass switch unit. At this time, the interference cancellation device is equivalent to not being connected to the radar, and does not affect the radar's normal reception of useful signals.

[0048] In one possible implementation, when the interference sensing module determines that interference exists, the interference cancellation device is connected to the radar for operation; the interference signal received by the sampling antenna module is then down-converted to an intermediate frequency signal, and then the digital intermediate frequency signal is converted into a digital intermediate frequency signal by the analog-to-digital conversion module and injected into the signal processing module;

[0049] The digital intermediate frequency signals of M sampling signals are weighted and synthesized in the digital domain through the signal processing module to obtain the interference cancellation signal; the interference cancellation signal is then synthesized with the digital intermediate frequency signal received by the radar in the digital domain to eliminate the interference signal in the radar received signal while retaining the useful signal; the adaptive filtering algorithm is used to iteratively adjust the weighted value of the sampling signal to minimize the output interference signal power after the sampling signal and the radar received signal are synthesized, while retaining the useful signal received by the radar.

[0050] In general, the above technical solutions conceived by this application have at least the following beneficial effects compared with the prior art:

[0051] This application provides a radar non-cooperative interference cancellation device and method. Compared with traditional non-cooperative electromagnetic interference protection methods, including frequency hopping and adaptive beamforming, this application is an active anti-interference measure with a higher interference suppression ratio. Compared with new interference protection methods, including waveform anti-interference and waveform diversity arrays, this application does not change the state of the radar transmitter and only processes the signal at the receiver. Therefore, it is easy to couple the design with existing radars and has strong engineering feasibility.

[0052] This application provides a radar non-cooperative interference cancellation device and method. The proposed interference protection method achieves a closed loop between perception and decision-making. Through the interference perception module, real-time perception of interference signals is achieved, and the interference cancellation device state can be controlled to achieve a dynamic closed loop. When there is no interference, the interference cancellation device is directly turned on, thus avoiding the impact of interference cancellation on radar detection performance when there is no interference.

[0053] The present application provides a radar non-cooperative interference cancellation device and method. When there is interference, the cancellation device is put into operation, and the sampling antenna module receives and samples the interference signal, eliminating the interference signal of the radar receiving link and retaining the useful signal; when there is no interference, the cancellation device is disconnected and bypassed, and the sampling antenna module does not receive the signal, which does not affect the normal antenna radiation pattern of the radar.

[0054] The present application provides a radar non-cooperative interference cancellation device and method. The proposed interference protection method realizes full-link amplitude and phase calibration of M channels including a switch matrix module, a sampling channel module, an analog-to-digital conversion module, a signal processing module and a digital-to-analog conversion module, thereby ensuring the amplitude and phase consistency of the sampling channel and improving the stability of the algorithm.

[0055] This application provides a radar non-cooperative interference cancellation device and method. By sharing radar signals such as the local oscillator signal and the transmit / receive switching signal with the radar, non-cooperative interference suppression performance is enhanced. By down-converting the shared local oscillator signal to an intermediate frequency (IF), the IF processing band and bandwidth of the interference cancellation device proposed in this application are consistent with those of the radar, enabling suppression of broadband interference at the RF end. By sharing the transmit / receive switching signal with the radar, local interference effects on the sampling antenna module and the corresponding receive link during radar transmission are avoided.

[0056] This application provides a radar non-cooperative interference cancellation device and method. This device utilizes a modular design with strong scalability, adapting to various radar types, including single-channel and multi-channel. By changing the sampling antenna, sampling channel module, and interference cancellation module, the number of channels can be freely adjusted. While a single set of modules, such as interference sensing and integrated control, can be used, multiple channels can be supported simultaneously. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1This is an architecture diagram of a non-cooperative interference cancellation device for a single-channel radar provided in an embodiment of the present application;

[0058] Figure 2 This is an architecture diagram of a non-cooperative interference cancellation device for multi-channel radar provided in an embodiment of the present application. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0060] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0061] Next, the technical solutions provided in the embodiments of this application are introduced.

[0062] Non-cooperative interference cancellation technology suppresses electromagnetic interference by adding non-cooperative interference cancellation devices. It can be applied to various types of information equipment and can be coupled with existing radars or integrated with newly developed radars. It has the characteristics of good interference suppression effect and strong engineering feasibility. This application realizes a closed loop of perception and decision-making by integrating interference perception modules and integrated control modules. In particular, when there is no interference, the interference cancellation device can intelligently perceive and automatically bypass it, avoiding the impact of interference cancellation on useful signals.

[0063] This application relates to the technical field of information equipment interference protection and discloses a radar non-cooperative interference cancellation method. By adding a radar interference cancellation device, the device works in conjunction with the radar to eliminate interference signals received by the radar. The radar interference cancellation device includes a sampling antenna module, a switch matrix module, a sampling channel module, an analog-to-digital conversion module, a signal processing module, a digital-to-analog conversion module, an integrated control module, an interference sensing module, and a channel calibration module. The sampling antenna module receives interference sampling signals from space and transmits the signals to the sampling channel module via the switch matrix module. The sampling channel module converts the received interference sampling signals to an intermediate frequency (IF). The analog-to-digital conversion module digitizes the converted interference sampling signals and the radar received signal and transmits them to the signal processing module. The signal processing module eliminates interference. The digital-to-analog conversion module converts the output signal of the signal processing module into a radio frequency signal and returns it to the radar receiving link. The integrated control module implements integrated control of the sampling channel module, signal processing module, and other modules. The interference sensing module senses interference and controls the operating state of the interference cancellation device. The channel calibration module calibrates the interference cancellation device. The device of the present application can be integrated with a single-channel or multi-channel radar to solve the non-cooperative interference problem faced by the radar.

[0064] In one embodiment, this application proposes a radar non-cooperative interference cancellation solution based on the demand for radar non-cooperative electromagnetic interference protection. By installing a radar non-cooperative interference cancellation device to work in conjunction with the radar, the interference signal received by the radar is eliminated. Figure 1 As shown, the non-cooperative interference cancellation device proposed in this application works in conjunction with the radar. The signal received by the sampling antenna module is converted and then enters the signal processing module. The radar received signal undergoes down-conversion to an intermediate frequency (IF) signal, which passes through the analog-to-digital conversion module of the non-cooperative cancellation device and then enters the signal processing module. After the cancellation device completes processing, the digital-to-analog conversion module returns the canceled signal to the radar's IF receive link. If the interference sensing module determines that there is no interference, the radar IF receive link is connected directly, bypassing the cancellation device.

[0065] like Figure 1 As shown, the interference cancellation device provided in the embodiment of the present application includes: a sampling antenna module, a sampling channel module, an analog-to-digital conversion module, a signal processing module, a digital-to-analog conversion module, an integrated control module, an interference perception module, a channel calibration module, etc.

[0066] The sampling antenna module includes a sampling antenna unit.

[0067] The switch matrix module includes a switch matrix unit.

[0068] The sampling channel module includes a sampling channel unit.

[0069] The analog-to-digital conversion module includes a sampling channel analog-to-digital conversion unit and a radar receiving channel analog-to-digital conversion unit.

[0070] The signal processing module includes a signal processing unit.

[0071] The digital-to-analog conversion module includes a digital-to-analog conversion unit.

[0072] The integrated control module includes a switch matrix module control unit, a sampling channel module control unit, a signal processing module control unit, an interference perception module control unit, and a parameter injection unit.

[0073] The interference sensing module includes an interference sensing unit and a bypass switch unit.

[0074] The channel calibration module includes a channel calibration unit.

[0075] Optionally, the sampling antenna module is connected to the sampling channel unit via a switch matrix module. The sampling channel module is then connected to the analog-to-digital conversion module. The analog-to-digital conversion module is connected to the signal processing module, which is then connected to the radar receive link after passing through the digital-to-analog conversion module. The integrated control module is respectively connected to the switch matrix module, the sampling channel module, the signal processing module, and the interference sensing module. The interference sensing module is connected to the signal processing module. The channel calibration module is connected to the signal processing module and the switch matrix module.

[0076] The received signal from the sampling antenna module passes through the sampling antenna module, switch matrix module, sampling channel module, and analog-to-digital conversion module. After being converted to a digital signal, one path enters the signal processing module. After signal processing, it is output to the radar receive link through the digital-to-analog conversion module; the other path enters the interference sensing module for interference sensing. After passing through the analog-to-digital conversion module, the radar received signal also enters the signal processing module for processing and is output to the radar receive link through the digital-to-analog conversion module. Various radar control signals are input to the integrated control module, which processes and controls the switch matrix module, sampling channel module, signal processing module, and interference sensing module. The interference sensing module inputs the sensing results to the signal processing module. The channel calibration module injects the calibration signal into the sampling channel module through the switch matrix module.

[0077] For example, the sampling antenna module includes N sampling antenna units, where N ≥ 2. The operating frequency band of the sampling antenna units is greater than or equal to the operating frequency band of the radar main antenna. The relative distance between the sampling antenna units and the radar main antenna in azimuth or elevation is greater than half the operating wavelength. The polarization mode of the sampling antenna units can be dual polarization, adjustable polarization, or single polarization. The N sampling antenna units are connected to a switch matrix module, which transmits received signals to the sampling channel module.

[0078] As an example, the switch matrix module includes a switch matrix unit. The switch matrix unit is an electronic switch matrix with electronic control. The first function of the switch matrix module is to receive calibration signals. When the radar non-cooperative interference cancellation device is in the calibration state, the switch matrix unit disconnects the sampling antenna module from the sampling channel module and injects the calibration signal from the channel calibration module into the sampling channel module. When the radar non-cooperative interference cancellation device is in the interference cancellation state, the switch matrix unit disconnects the channel calibration module from the sampling channel module and injects the received signal from the sampling antenna module into the sampling channel module.

[0079] The switch matrix module's second function is to select the sampling antenna units. The switch matrix unit can select some sampling antenna units, or the received signals from the sampling antenna unit ports, and send them to the sampling channel module. Under the control of the switch matrix unit, a total of M sampling antenna unit received signals enter the sampling channel module, where N ≥ M ≥ 2.

[0080] In one example, the sampling channel module includes a sampling channel unit. The radar receiver utilizes superheterodyne reception. The radar local oscillator signal is injected into the sampling channel module. The received signal from the sampling antenna module is down-converted to an intermediate frequency (IF) through filtering, amplification, and mixing. Because the signal shares the same LO with the radar, this IF is equal to the radar IF. The number of down-conversion stages in the sampling channel module matches that of the radar receiver.

[0081] Filtering is accomplished by preselection filters and intermediate frequency filters after various stages of downconversion. Amplification is accomplished by amplifiers or attenuators with controllable, adjustable, or fixed gain, including fixed-gain low-noise amplifiers (LNAs), automatic gain controllers (AGCs), time-sensitive gain controllers (STCs), and adjustable attenuators. Mixing is accomplished by mixers.

[0082] Optionally, the analog-to-digital conversion module includes a sampling channel analog-to-digital conversion unit and a radar receiving channel analog-to-digital conversion unit. The sampling channel analog-to-digital conversion unit receives the intermediate frequency signal output by the sampling channel module and generates a digital intermediate frequency signal of the sampling signal after analog-to-digital conversion.

[0083] The radar receiving intermediate frequency signal enters the radar receiving channel analog-to-digital conversion unit and forms a radar receiving signal digital intermediate frequency signal after analog-to-digital conversion.

[0084] It is understood that the signal processing module includes signal processing units. The digital intermediate frequency signal of the sampled signal and the digital intermediate frequency signal of the radar received signal are output to the signal processing units together. The input signal of each signal processing unit includes M digital intermediate frequency signals of the sampled signal and one digital intermediate frequency signal of the radar received signal.

[0085] It is understood that the digital-to-analog conversion module includes a digital-to-analog conversion unit, which is connected to the signal processing unit and converts the digital signal output by the signal processing unit into a radar intermediate frequency (IF) and inputs the signal into the radar IF receiving link.

[0086] It can be understood that the integrated control module includes a switch matrix module control unit, a sampling channel module control unit, a signal processing module control unit, an interference perception module control unit, and a parameter injection unit.

[0087] The switch matrix module control unit is connected to the switch matrix module and is used to control the gating of the switch matrix units in the switch matrix module.

[0088] The sampling channel module control unit is connected to the sampling channel module and is used to control the amplifier gain in the sampling channel module, thereby controlling the total link gain of the entire sampling channel module.

[0089] The signal processing module control unit is connected to the signal processing module and is used to control the parameter settings of the signal processing unit in the signal processing module.

[0090] The interference sensing module control unit is connected to the interference sensing module and is used to control parameter settings of the interference sensing unit in the interference sensing module.

[0091] The parameter injection unit is connected to the radar and switch matrix module control unit, sampling channel module control unit, etc. at the same time, and is used to receive and analyze radar transceiver control signals, side angle signals, gain control signals and other signals.

[0092] Optionally, the interference sensing module includes an interference sensing unit and a bypass switch unit. The bypass switch unit is connected to the radar intermediate frequency receiving link and is used to control the switching between interference protection and bypass functions, and is controlled by the interference sensing unit.

[0093] The interference sensing unit receives the digital IF signal from the analog-to-digital conversion module. If the interference sensing unit detects interference, the bypass switch disconnects the radar's IF link. The IF signal passes through the radar's receive link's analog-to-digital conversion unit and enters the signal processing unit for anti-interference processing. The output signal then passes through the digital-to-analog conversion unit and returns to the radar's IF link. If the interference sensing unit determines there is no interference, the bypass switch bypasses the radar's non-cooperative interference cancellation device, allowing the radar's IF receive link to continue.

[0094] Optionally, the channel calibration module includes a channel calibration unit. The channel calibration unit is connected to the switch matrix module. When in calibration mode, the switch matrix connects the channel calibration unit to the sampling channel module. The channel calibration unit generates a calibration signal and inputs the calibration signal to the sampling channel module. The channel calibration unit is also connected to the signal processing unit to receive and analyze the calibration signal, thereby completing calibration of the receiving chain including the sampling channel module and the analog-to-digital conversion module.

[0095] The channel calibration unit can also receive and analyze the calibration signal generated by the external calibration source. At this time, the switch matrix connects all or part of the sampling antenna units to be calibrated to the sampling channel module. The external calibration source sends the calibration signal to the sampling antenna unit. The calibration signal passes through the sampling antenna module, sampling channel module, analog-to-digital conversion module, signal processing module, etc. to reach the calibration function unit, thereby completing the calibration of the entire receiving chain including the sampling antenna module.

[0096] Furthermore, the interference cancellation method based on the above-mentioned radar non-cooperative interference cancellation device provided in the embodiment of the present application specifically includes the following steps:

[0097] Step S1: Install a radar non-cooperative interference cancellation device to work in conjunction with the radar, and inject the required radar receiving signal and control signal into the radar non-cooperative interference cancellation device;

[0098] Step S2: The sampling antenna module receives the signal in space and sends it to the sampling channel module through the switch matrix unit. The signal is down-converted to an intermediate frequency signal by sharing the local oscillator with the signal received by the radar main antenna. After passing through the analog-to-digital conversion module, a digital intermediate frequency signal is formed and input into the interference perception module and the signal processing module.

[0099] Step S3: If the interference sensing module determines that there is no interference, the cancellation device is bypassed via the bypass switch. This effectively disables the cancellation device from the radar, preventing it from affecting the radar's reception of useful signals. If the interference sensing module determines that there is interference, the cancellation device is connected to the radar, and the process proceeds to the next step.

[0100] Step S4: The radar received signal is down-converted and then passes through the analog-to-digital conversion module to form a digital intermediate frequency signal which is injected into the signal processing module;

[0101] Step S5: Each signal processing module performs weighted synthesis of the digital intermediate frequency signals of the M sampling signals in the digital domain to obtain an interference cancellation signal;

[0102] Step S6: The interference cancellation signal and the digital intermediate frequency signal of the radar receiving signal are synthesized in the digital domain to eliminate the interference signal and retain the useful signal in the radar receiving signal;

[0103] Step S7: The signal processing module uses an adaptive filtering algorithm to iteratively adjust the weighted value of the sampled signal to minimize the power of the output interference signal after the sampled signal and the radar received signal are synthesized, while retaining the useful signal received by the radar;

[0104] Step S8: The parameter injection module receives and analyzes the radar transmit / receive switching signal, so that the signal processing module updates the weights in accordance with the following rules: at the beginning of the radar transmit time slot, the weights remain at the previous value until the beginning of the radar receive time slot. The weights are adaptively updated from the beginning to the end of the radar receive time slot.

[0105] As you can understand, the modular design allows for adaptability to single-channel or multi-channel radars. Multi-channel radars can be adapted by increasing or decreasing the number of sampling channel modules and signal processing modules. The interference sensing module and integrated control module, among others, enable one-to-many operation, meaning a single set of modules can simultaneously support multiple channels.

[0106] In another embodiment, Figure 2 As shown, the non-cooperative interference cancellation device proposed in this application can work in conjunction with a multi-channel radar. In this embodiment, the monopulse angle-measuring radar is divided into a sum channel and a difference channel for reception. The proposed interference cancellation device is also divided into two corresponding channels, each of which includes a sampling channel module, an analog-to-digital conversion module, an interference cancellation module, and a digital-to-analog conversion module. The other channels of the interference cancellation device can achieve one-to-many operation.

[0107] It should be understood that expressions such as "include" and "may include" used in this application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In this application, terms such as "include" and / or "have" may be interpreted as indicating specific characteristics, numbers, operations, constituent elements, components, or combinations thereof, but may not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0108] In addition, in this application, the expression "and / or" includes any and all combinations of the associated listed words. For example, the expression "A and / or B" may include A, may include B, or may include both A and B.

[0109] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. Among them, "fixed connection" means that the two are connected to each other and the relative position relationship after the connection remains unchanged. "Rotational connection" means that the two are connected to each other and can rotate relative to each other after the connection. "Sliding connection" means that the two are connected to each other and can slide relative to each other after the connection. The directional terms mentioned in the embodiments of the present application, such as "top", "bottom", "inside", "outside", "left", "right", etc., are only reference to the directions of the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of the present application, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0110] In addition, in the embodiments of the present application, the mathematical concepts mentioned include symmetry, equality, parallelism, and perpendicularity. These limitations are all for the current state of the art, rather than being absolutely strict definitions in a mathematical sense. A small amount of deviation is allowed, and it is possible to be approximately symmetric, approximately equal, approximately parallel, or approximately perpendicular. For example, A and B are parallel, which means that A and B are parallel or approximately parallel, and the angle between A and B can be between 0 and 10 degrees. A and B are perpendicular, which means that A and B are perpendicular or approximately perpendicular, and the angle between A and B can be between 80 and 100 degrees.

[0111] It will be understood that the various numerical numbers involved in the embodiments of the present application are merely distinctions for the convenience of description and are not intended to limit the scope of the embodiments of the present application.

[0112] It is easy for those skilled in the art to understand that the above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A radar non-cooperative interference cancellation device, characterized in that: include: Sampling antenna module, switch matrix module, sampling channel module, signal processing module and interference perception module; The sampling antenna module is used to sample the interference signal of at least one radar; the sampling antenna module includes N sampling antenna units, each sampling antenna unit has an operating frequency band greater than or equal to the operating frequency band of a radar main antenna, and is used to receive the spatial interference signal for sampling; The switch matrix module is used to connect to the N sampling antenna units of the sampling antenna module; the switch matrix module includes N channels, and selects signals received by M sampling antenna units to be sent to the sampling channel module; N≥M≥2, where N and M are both positive integers; The sampling channel module is used to amplify, filter and convert the received M sampling signals into intermediate frequency signals; The interference sensing module is configured to sense whether there is interference in the intermediate frequency signal received by the radar. When interference is determined to be present, the radar's receiving link is disconnected, so that the intermediate frequency signal of the radar receiving link is first input to the signal processing module before being output back; and when no interference is detected, the interference cancellation device is bypassed from the radar receiving link. The signal processing module includes a multi-domain joint interference cancellation algorithm unit, which executes a multi-domain joint interference cancellation algorithm based on the characteristic differences between the interference signal and the useful signal in the spatial domain, time domain, frequency domain, energy domain and polarization domain, and is used to cancel the interference signal of the radar receiving link by combining M-channel sampling signals.

2. The device according to claim 1, characterized in that The relative distance between the sampling antenna unit and the radar main antenna in azimuth or elevation is greater than half the operating wavelength.

3. The device according to claim 1, characterized in that Also includes: Analog-to-digital conversion module and digital-to-analog conversion module; The analog-to-digital conversion module is connected between the sampling channel module and the signal processing module, and is used to digitize the M-channel sampling signals after frequency conversion and the signal of the radar link and send them to the signal processing module; The digital-to-analog conversion module is connected to the output end of the signal processing module and is used to convert the signal processed by the signal processing module into an intermediate frequency analog signal and then play it back to the radar receiving link.

4. The device according to claim 3, characterized in that Also includes: Channel calibration module; One end of the channel calibration module is connected to the switch matrix module, and the other end is connected to the digital-to-analog conversion module. When the interference cancellation device is in the calibration mode, the switch matrix module connects the channel calibration module with the sampling channel module; when the interference cancellation device is in the receiving mode, the switch matrix module connects the sampling antenna module with the sampling channel module. When the interference cancellation device is in a calibration mode, the channel calibration module inputs a calibration signal to the switch matrix module; The sampling channel module converts the frequency of the calibration signal and outputs it to the analog-to-digital conversion module; The analog-to-digital conversion module converts the received frequency-converted signal into a digital signal and outputs it to the signal processing module; The signal processing module analyzes and processes the received digital signal to complete full-link amplitude and phase calibration of the M channels composed of the switch matrix module, sampling channel module, analog-to-digital conversion module, signal processing module and digital-to-analog conversion module.

5. The device according to claim 4, characterized in that The switch matrix module includes: a switch matrix unit; The switch matrix module is connected to the channel calibration module and is used to receive a calibration signal input by the channel calibration module.

6. The device according to claim 5, characterized in that When the interference cancellation device is in a calibration state, the switch matrix unit disconnects the sampling antenna module from the sampling channel module and injects the calibration signal of the channel calibration module into the sampling channel module.

7. The device according to claim 5, characterized in that When the radar non-cooperative interference cancellation device is in a receiving mode, the switch matrix unit disconnects the channel calibration module from the sampling channel module and injects the signal received by the sampling antenna module into the sampling channel module; The switch matrix unit selects M sampling antenna units or the receiving signals of M sampling antenna unit ports and sends them to the sampling channel module.

8. The device according to claim 1, characterized in that Also includes: integrated control module; The integrated control module includes: a switch matrix module control unit, a sampling channel module control unit, a signal processing module control unit, an interference perception module control unit, a channel calibration module control unit and a parameter injection unit; The switch matrix module control unit is connected to the switch matrix module and is used to control the gating of the switch matrix units in the switch matrix module; The sampling channel module control unit is connected to the sampling channel module and is used to control the amplifier gain in the sampling channel module, thereby controlling the total gain of the entire sampling channel module link; The signal processing module control unit is connected to the signal processing module and is used to control the parameter settings of the signal processing unit in the signal processing module; The interference sensing module control unit is connected to the interference sensing module and is used to control the parameter settings of the interference sensing unit in the interference sensing module; The channel calibration module control unit is connected to the channel calibration module and is used to control the parameter settings of the channel calibration unit in the channel calibration module; The parameter injection unit is connected to the radar and switch matrix module control unit and the sampling channel module control unit, and is used to receive and analyze the radar transceiver control signal, the side angle signal and the gain control signal, so that the signal processing module complies with the following rules when updating the weight: at the beginning of the radar transmission time slot, the weighted weight remains at the weight of the previous moment until the beginning of the radar reception time slot; from the beginning to the end of the radar reception time slot, the weighted weight is adaptively updated.

9. A radar non-cooperative interference cancellation method based on the device according to any one of claims 1 to 8, characterized in that: The steps include: Step S1. When the radar non-cooperative interference cancellation device is powered on or reset, the device automatically enters the channel calibration mode and performs full-link amplitude and phase calibration on the sampling channel consisting of the N-routing switch matrix module, sampling channel module, analog-to-digital conversion module, signal processing module, and digital-to-analog conversion module; Step S2. After receiving the calibration completion instruction, the device enters the channel receiving mode, and N sampling antenna units sample at least one radar interference signal; the operating frequency band of each sampling antenna unit is greater than or equal to the operating frequency band of the radar main antenna, and is used to receive and sample the corresponding radar interference signal; Step S3. Select M sampling antenna units to send the received signals to the sampling channel module; N ≥ M ≥ 2, where N and M are both positive integers; Step S4. Convert the M sampling signals received by the sampling channel module into intermediate frequency signals; Step S5. Convert the M-channel sampled intermediate frequency signals and the radar received intermediate frequency signal into digital signals respectively, and perform interference sensing processing; Step S6. When interference is detected in the radar receive signal, the radar receive link is disconnected, so that the received signal of the radar link is first input into the signal processing module and combined with the M-channel sampled signals for interference cancellation processing before being replayed back to the radar receive link; Step S7: When it is detected that there is no interference in the radar receiving signal, the interference cancellation device is bypassed from the radar receiving link.

10. The method according to claim 9, characterized in that The relative distance between the sampling antenna unit and the radar main antenna in azimuth or elevation is greater than half the operating wavelength.

11. The method according to claim 9, characterized in that Also includes: Connect one end of the channel calibration module to the switch matrix module and the other end to the digital-to-analog conversion module. When the interference cancellation device is in the calibration mode, connect the channel calibration module to the sampling channel module through the switch matrix module. When the interference cancellation device is in calibration mode, the channel calibration module inputs a calibration signal to the switch matrix module, and then outputs the calibration signal to the analog-to-digital conversion module through the sampling channel module. After being converted into a digital signal, it enters the signal processing module for analysis and processing, so as to complete the full-link amplitude and phase calibration of the M channels composed of the switch matrix module, sampling channel module, analog-to-digital conversion module, signal processing module and digital-to-analog conversion module.

12. The method according to any one of claims 9 to 11, characterized in that The radar interference sampling signal is received in space by the sampling antenna unit and sent to the sampling channel module through the switch matrix module. It is down-converted to an intermediate frequency signal by sharing the local oscillator with the radar main antenna receiving signal. After passing through the analog-to-digital conversion module, it forms a digital intermediate frequency signal and is input into the interference perception module and signal processing module. When the interference sensing module determines that there is no interference, the interference cancellation device is bypassed through the bypass switch unit. At this time, the interference cancellation device is equivalent to not being connected to the radar, and does not affect the radar's normal reception of useful signals.

13. The method according to any one of claims 9 to 11, characterized in that When the interference sensing module determines that interference exists, the interference cancellation device is connected to the radar to operate; then the interference signal received by the sampling antenna module is down-converted to an intermediate frequency signal, and then the digital intermediate frequency signal is generated by the analog-to-digital conversion module and injected into the signal processing module; The digital intermediate frequency signals of M sampling signals are weighted and synthesized in the digital domain through the signal processing module to obtain the interference cancellation signal; the interference cancellation signal is then synthesized with the digital intermediate frequency signal received by the radar in the digital domain to eliminate the interference signal in the radar received signal while retaining the useful signal; the adaptive filtering algorithm is used to iteratively adjust the weighted value of the sampling signal to minimize the output interference signal power after the sampling signal and the radar received signal are synthesized, while retaining the useful signal received by the radar.

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