Radar signal processing system and method

Abstract

The embodiment of the invention provides a radar signal processing system and method, and relates to the field of radar signal processing, the system comprises an antenna extension set and a channel signal processing and wave control extension set, the channel signal processing and wave control extension set comprises an integrated channel module, a signal sampling and baseband processing module, an information processing module and a wave beam control module, the antenna extension set is used for receiving an echo signal, obtaining a radio frequency signal based on the received echo signal and sending the radio frequency signal to the channel signal processing wave control extension set, the integrated channel module is used for processing the radio frequency signal to obtain a first signal, and the signal sampling and baseband processing module is used for processing the first signal to obtain a second signal and sending the second signal to the antenna extension set. The information processing module is used for processing the second signal to obtain a third signal, the beam control module is used for carrying out beam forming on the third signal to obtain a beam signal and sending the beam signal to the antenna extension set, and compared with an existing phased array radar system architecture, communication transmission delay is reduced.

Description

Technical Field

[0001] The present invention relates to the field of radar signal processing, and in particular, to a radar signal processing system and method. Background Art

[0002] Radar technology is a technology that uses transmitted electromagnetic waves to irradiate a target and receive its echo, and obtains information such as the distance, azimuth, and altitude of the target through algorithm processing.

[0003] At the beginning of the 21st century, the radar industry mainly consisted of mechanical radars. The mechanical radar concentrated on transmitting signal waves at one position, and through the rotation of the mechanical turntable, the signal waves were transmitted in different directions to detect different targets. However, its mechanical rotation efficiency was low, and the detection area and detection targets were limited, no longer adapting to the increasingly complex development direction of the electromagnetic field.

[0004] In recent years, phased array technology has gradually expanded in the radar field. The phased array radar realizes multi-beam fast scanning detection through feed control of the electromagnetic beam electronic scanning, and can also flexibly control the beam shape according to the actual environment. It is far superior to mechanical radars in terms of reaction speed, target update rate, multi-target tracking ability, electronic countermeasure ability, etc., and has become the main development direction of the current radar industry.

[0005] The current mainstream phased array system architecture mainly consists of an antenna sub-unit (including a beam control module), a channel sub-unit, a signal processing sub-unit, and a power supply sub-unit. The antenna sub-unit receives signals, the channel sub-unit performs signal spectrum shifting, the signal processing sub-unit processes the data and feeds back the information to the antenna sub-unit for beam control, realizing a closed loop of the signal link and control. Such a system architecture usually involves complex hardware circuit design and signal processing control design, and requires close cooperation among each sub-unit to correctly realize the main functions of the entire system. Summary of the Invention

[0006] The purpose of the present invention is to provide a radar signal processing system and method, which can reduce the complexity of the system.

[0007] To achieve the above object, the technical solutions adopted in the embodiments of the present application are as follows:

[0008] In a first aspect, the embodiments of the present application provide a radar signal processing system, the system includes: an antenna sub-unit and a channel signal processing and beam control sub-unit, and the channel signal processing and beam control sub-unit includes an integrated channel module, a signal sampling and baseband processing module, an information processing module, and a beam control module;

[0009] The antenna sub-unit is used to receive the echo signal, obtain a radio frequency signal based on the received echo signal, and send the radio frequency signal to the channel signal processing and beam control sub-unit;

[0010] The integrated channel module is used to perform frequency synthesis and filtering processing on the radio frequency signal to obtain a first signal;

[0011] The signal sampling and baseband processing module is used to perform preprocessing, pulse compression processing, MTD processing, and CFAR processing on the first signal in sequence to obtain a second signal;

[0012] The information processing module is used to perform speed calculation, distance prediction, angle filtering, track association, and strapdown de-scrambling on the second signal to obtain a third signal;

[0013] The beam control module is used to perform beamforming on the third signal to obtain a beam signal, and send the beam signal to the antenna sub-unit.

[0014] In an alternative embodiment, the system further includes an SOC chip;

[0015] The SOC chip includes a programmable logic unit and an ARM processor;

[0016] The signal sampling and baseband processing module and the beam control module are integrated in the programmable logic unit;

[0017] The information processing module is integrated in the ARM processor.

[0018] In an alternative embodiment, the programmable logic unit includes a timing control module;

[0019] The timing control module is used to control the working states of the signal sampling and baseband processing module, the information processing module, and the beam control module, so as to control the synchronization of the processing processes of the signal sampling and baseband processing module, the information processing module, and the beam control module.

[0020] In an alternative embodiment, the programmable logic unit and the ARM processor are communicatively connected through an AXI bus.

[0021] In an alternative embodiment, the beam control module includes N serialization sub-modules;

[0022] Each of the serialization sub-modules is used to process the third signal in parallel to obtain a plurality of beam sub-signals;

[0023] A beam signal is formed based on the plurality of beam sub-signals.

[0024] In an alternative embodiment, the antenna sub-unit includes an antenna array, a power supply module, and a TR chip;

[0025] The antenna array is used to receive and transmit signals in a specific direction in space, and synthesize the echo signals through the TR chip to obtain radio frequency signals, and send the radio frequency signals to the channel signal processing and wave control sub - machine;

[0026] The power supply module is used to supply power to the radar processing system.

[0027] In an alternative embodiment, the integrated channel module is specifically configured to:

[0028] Perform frequency synthesis processing on the radio frequency signal to obtain a first radio frequency signal;

[0029] Perform programmable filtering and frequency conversion processing on the first radio frequency signal to obtain an intermediate frequency signal;

[0030] Use the intermediate frequency signal as the first signal.

[0031] In an alternative embodiment, the pre - processing includes:

[0032] Sample the echo signal through an analog - to - digital converter and convert it into a digital signal;

[0033] Filter the digital signal based on a filter to obtain a filtered digital signal;

[0034] Decimate the filtered digital signal according to a preset ratio to obtain a second digital signal;

[0035] Determine the delay parameter of the filter, and compensate the second digital signal based on the delay parameter to obtain a signal after pre - processing the first signal.

[0036] In an alternative embodiment, the pulse compression includes:

[0037] Perform optimal matched filtering processing on the signal after pre - processing the first signal to obtain a first filtered signal;

[0038] Perform phase - coherent synthesis on the first filtered signal in the time domain to obtain a signal after pulse compression processing of the signal after pre - processing the first signal.

[0039] In a second aspect, an embodiment of the present application provides a radar signal processing method, which processes the received radar signals through the radar signal processing system.

[0040] The present application has the following beneficial effects:

[0041] This application designs a radar signal processing system, which includes: an antenna sub - unit and a channel, signal processing, and beam control sub - unit. The channel, signal processing, and beam control sub - unit includes an integrated channel module, a signal sampling and baseband processing module, an information processing module, and a beam control module. The antenna sub - unit is used to receive echo signals, obtain radio frequency signals based on the received echo signals, and send the radio frequency signals to the channel, signal processing, and beam control sub - unit. The integrated channel module is used to perform frequency synthesis and filtering on the radio frequency signals to obtain a first signal. The signal sampling and baseband processing module is used to perform pre - processing, pulse compression processing, MTD processing, and CFAR processing on the first signal in sequence to obtain a second signal. The information processing module is used to perform speed calculation, distance prediction, angle filtering, track association, and strap - down de - scrambling on the second signal to obtain a third signal. The beam control module is used to perform beam forming on the third signal to obtain a beam signal and send the beam signal to the antenna sub - unit. Compared with the existing phased array radar system architecture, the structural design is simpler, enabling faster transmission between radar signals, thereby reducing communication transmission delay. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0043] Figure 1 One of the schematic diagrams of a radar signal processing system provided by an embodiment of the present invention;

[0044] Figure 2 Another schematic diagram of a radar signal processing system provided by an embodiment of the present invention;

[0045] Figure 3 One of the flow schematic diagrams of a radar signal processing method provided by an embodiment of the present invention;

[0046] Figure 4 Schematic diagram of the antenna sub - unit provided by an embodiment of the present invention;

[0047] Figure 5 Another flow schematic diagram of a radar signal processing method provided by an embodiment of the present invention;

[0048] Figure 6 Another flow schematic diagram of a radar signal processing method provided by an embodiment of the present invention;

[0049] Figure 7 Another flow schematic diagram of a radar signal processing method provided by an embodiment of the present invention. Detailed Implementation Modes

[0050] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. The components of the embodiments of the present invention usually described and illustrated in the drawings here can be arranged and designed in various different configurations.

[0051] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0052] It should be noted that like reference numerals and letters denote like items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0053] In the description of the present invention, it should be noted that if terms such as "upper", "lower", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, or the orientations or positional relationships in which the products of the present invention are usually placed during use, it is only for the convenience of describing the present invention and simplifying the description, 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 should not be construed as a limitation to the present invention.

[0054] In addition, terms such as "first" and "second" are only used for descriptive distinction and should not be construed as indicating or implying relative importance.

[0055] In the description of the present application, it should also be noted that unless otherwise clearly defined and limited, the terms "arranged", "installed", "connected" and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0056] Through research, it is found that radar technology is a technology that uses transmitted electromagnetic waves to irradiate a target and receives its echo, and obtains information such as the distance, azimuth and altitude of the target through algorithm processing.

[0057] At the beginning of the 21st century, the radar industry in China mainly relied on mechanical radars. Mechanical radars emit signal waves from a single location and rotate the mechanical turntable to direct the signal waves in different directions for detecting different targets. However, their mechanical rotation efficiency is low, and the detection area and targets are limited, making them no longer suitable for the increasingly complex development direction of electromagnetic fields.

[0058] In recent years, phased array technology has gradually expanded in the radar field. Phased array radars use feed control for electronic scanning of electromagnetic beams to achieve fast multi-beam scanning detection. They can also flexibly control the beam shape according to the actual environment and are far superior to mechanical radars in terms of response speed, target update rate, multi-target tracking ability, and electronic countermeasure ability, becoming the main development direction of the current radar industry.

[0059] The current mainstream phased array system architecture mainly consists of an antenna sub-unit (including a beam control module), a channel sub-unit, a signal processing sub-unit, and a power supply sub-unit. The antenna sub-unit receives signals, the channel sub-unit performs signal spectrum shifting, the signal processing sub-unit processes the data and feeds back the information to the antenna sub-unit for beam control, thus realizing the closed-loop of the signal link and control. Such a system architecture usually involves complex hardware circuit design and signal processing control design, requiring close cooperation among the sub-units to correctly achieve the main functions of the entire system.

[0060] However, under the existing system architecture, there are also many technical problems that are difficult to solve;

[0061] The system architecture is complex. Especially, beam control is affected by information transmission, and the beam pointing lags due to communication transmission delay, reducing the advantage of the electronic beam scanning of phased array radars;

[0062] Beam control and timing control are independent, and the signal processing results and beam pointing information are not synchronized. Beam changes may affect the timing and processing results of radar signal processing;

[0063] Since the number of array elements in phased array antennas is often large, each array element needs to synthesize the beam direction using phase relationships, and a large amount of processing time is required for calculating the phase information of each array element. Especially for phased array radar systems mounted on moving platforms, due to the need to update the beam pointing de-scrambling in real time through strapdown information, the traditional beam phase calculation method is difficult to meet the requirements of high-precision strapdown de-scrambling.

[0064] In view of the discovery of the above problems, this embodiment provides a radar signal processing system and method. The system includes: an antenna sub-system and a channel signal processing and beam control sub-system. The channel signal processing and beam control sub-system includes an integrated channel module, a signal sampling and baseband processing module, an information processing module, and a beam control module. The antenna sub-system is used to receive echo signals, obtain radio frequency signals based on the received echo signals, and send the radio frequency signals to the channel signal processing and beam control sub-system. The integrated channel module is used to perform frequency synthesis and filtering processing on the radio frequency signals to obtain a first signal. The signal sampling and baseband processing module is used to perform preprocessing, pulse compression processing, MTD processing, and CFAR processing on the first signal in sequence to obtain a second signal. The information processing module is used to perform speed calculation, distance prediction, angle filtering, track association, and strapdown de-scrambling on the second signal to obtain a third signal. The beam control module is used to perform beam forming on the third signal to obtain a beam signal and send the beam signal to the antenna sub-system. Compared with the existing phased array radar system architecture, the structural design is simpler, making the transmission of radar signals faster, thereby reducing the communication transmission delay. The solution provided in this embodiment will be elaborated in detail below.

[0065] Please refer to Figure 1 , Figure 1 which is a schematic structural diagram of a radar signal processing system. Each module included in the system will be elaborated in detail below.

[0066] The radar signal processing system includes: an antenna sub-system 1 and a channel signal processing and beam control sub-system 2. The channel signal processing and beam control sub-system 1 includes an integrated channel module 21, a signal sampling and baseband processing module 22, an information processing module 23, and a beam control module 24;

[0067] The antenna sub-system 1 is used to receive echo signals, obtain radio frequency signals based on the received echo signals, and send the radio frequency signals to the channel signal processing and beam control sub-system;

[0068] The integrated channel module 21 is used to perform frequency synthesis and filtering processing on the radio frequency signals to obtain a first signal;

[0069] The signal sampling and baseband processing module 22 is used to perform preprocessing, pulse compression processing, MTD processing, and CFAR processing on the first signal in sequence to obtain a second signal;

[0070] The information processing module 23 is used to perform speed calculation, distance prediction, angle filtering, track association, and strapdown de-scrambling on the second signal to obtain a third signal;

[0071] The beam control module 24 is used to perform beam forming on the third signal to obtain a beam signal and send the beam signal to the antenna sub-system 1.

[0072] The antenna sub - unit is used for the echo signal of the target. The echo signal usually contains the reflection information, noise and clutter of the target.

[0073] The integrated channel module is the first signal - processing module in the radar system. Its main function is to perform preliminary processing on the RF signal received by the antenna. The specific steps include: amplifying the received weak signal while minimizing the introduction of noise; converting the high - frequency RF signal into an intermediate - frequency signal for subsequent processing; removing the unwanted frequency bands through a band - pass filter to reduce out - of - band noise and interference; distributing the processed signal to multiple processing channels to prepare for subsequent parallel processing to obtain the first signal.

[0074] The signal sampling and base - band processing module converts the analog signal into a digital signal and performs preliminary digital - signal processing. Specifically, it includes: sampling and converting the first signal, i.e., the intermediate - frequency signal, into a digital signal, further converting the intermediate - frequency digital signal into a base - band signal, and extracting the real and imaginary parts of the signal; performing pre - processing operations such as filtering, denoising, and gain adjustment on the base - band signal; compressing the long - pulse signal through a matched filter to improve the resolution; estimating the Doppler frequency shift of the signal to distinguish stationary targets and moving targets; detecting and tracking moving targets through a Doppler filter bank and a constant false - alarm rate detection algorithm; estimating parameters such as the position, velocity, and acceleration of the target; associating the detected targets with known targets to update the target trajectory; suppressing clutter such as ground and sea clutter through a clutter map or an adaptive filter; fusing data from multiple radars or other sensors to improve the accuracy of target detection and tracking to obtain the second signal.

[0075] The information - processing module performs speed calculation, distance prediction, angle filtering, track association, and strap - down de - scrambling on the second signal to obtain the third signal.

[0076] The beam - control module resolves the third signal issued by the information - processing module into the phase information of the antenna elements and finally updates the antenna pointing angle.

[0077] Under the premise of not violating the top - down design principle, this application divides the system into an antenna sub - unit and a channel, signal - processing, and beam - control sub - unit, combines the signal processing and the beam - control module. The calculation results of the signal processing can be fed back to the beam - control module in real time, greatly reducing the impact of beam lag caused by processing delay and information - transfer delay. Through the above solution, it can effectively solve the matching problem between phased - array beam control and signal processing, combine phased - array technology with the traditional radar signal - processing process, and play a positive role in popularizing the use of phased - array antennas.

[0078] The radar signal - processing system also includes an SOC chip 3, such as Figure 2As shown, the SOC chip includes a programmable logic unit 31 and an ARM processor 32. The signal sampling and baseband processing module 22 and the beam control module 24 are integrated in the programmable logic unit 31; the information processing module 23 is integrated in the ARM processor 32.

[0079] Still referring to Figure 2 , the programmable logic unit 31 includes a timing control module 33;

[0080] The timing control module 33 is used to control the working states of the signal sampling and baseband processing module 22, the information processing module 23, and the beam control module 24, so as to control the synchronization of the processing processes of the signal sampling and baseband processing module 22, the information processing module 23, and the beam control module 24.

[0081] The main function of the timing control module is to generate and distribute precise timing pulses to control the working states of various modules in the radar system. These pulses include transmit pulses, receive pulses, sampling pulses, etc., ensuring strict synchronization in the processes of radar transmission, reception, and signal processing.

[0082] The timing control module is mostly implemented by a programmable logic unit. The programmable logic unit has characteristics such as high precision, high reliability, strong reconfigurability, and good scalability, and can flexibly generate complex timing signals. For example, through the programmable logic unit, dynamic adjustment of parameters such as transmit pulse width, pulse repetition frequency (PRF), and receive window width can be achieved.

[0083] To improve versatility and scalability, the timing control module usually adopts a modular design method. For example, according to the requirements of the radar system, a reference repetition frequency counting module, a time parameter decoding module, a pulse width counting module, etc. can be designed. These modules are connected by the logic circuits of the programmable logic unit to achieve flexible timing control.

[0084] In a multi-channel radar system, the timing control module can achieve coordinated operation of multiple channels through time-division multiplexing technology. For example, by utilizing the timing management and constraint capabilities of the programmable logic unit, multiple clock signals with the same frequency but different phases are generated by frequency division and counting timing of the reference clock, thus avoiding crosstalk between channels.

[0085] The timing control module enables the signal sampling and baseband processing module, the information processing module, and the beam control module to work under the timing generated by the timing control module and be synchronously controlled by the timing signal. The signal sampling and baseband processing module, the information processing module, and the beam control module complete the signal processing and calculation before the arrival of the frame synchronization signal, and output the processing result in response to the frame synchronization signal, so that the signal processing result, the current beam pointing information, and the signal detection calculation result match each other, minimizing the system processing delay as much as possible, and being able to output the real-time detection result and form a working closed-loop as much as possible. Especially for radar systems with high frequency bands, narrow beams, and detecting highly maneuverable targets, it has very good effects.

[0086] One transmission and reception cycle of the radar signal is the minimum time processing unit for radar signal processing, called PRT; multiple PRTs form a CPI time, and multiple CPIs form a beam dwell time. The update of the beam pointing is synchronized with the beam dwell time, and it is updated once per beam dwell. Radar signal processing needs to be completed within one CPI time, and radar signal detection needs to be completed within one beam dwell time. The radar echo signal received under the current beam pointing must be synchronized with the processing result. The timing control module is to make all modules complete signal processing, detection, and beam pointing update within the specified time.

[0087] It should be noted that the programmable logic unit and the ARM processor are communicatively connected through the AXI bus. The programmable logic unit is the PL, and the PL is the integrated FPGA resource, mainly responsible for the baseband processing and beam control functions of radar signals. The ARM processor is the PS, and the PS is the integrated ARM resource, mainly responsible for the information detection and calculation of radar signals, as well as the control of system operation.

[0088] Using the data interaction method of the AXI bus between the PS and the PL, the information interaction method between the beam control module and the information detection and calculation module is greatly simplified. Since there is no need for traditional transmission hardware interfaces and no need to consider the delay caused by transmission and caching, the information transmission between modules can be completed with the shortest delay, providing a basis for the synchronization of radar inter-frame data and beam pointing. At the same time, compared with the traditional architecture scheme, there is no need for idle frames to match the transmission and processing delays during the radar signal processing process, which can effectively improve the performance of the radar.

[0089] As Figure 3 shown, it is the processing flow chart of the beam control module, including the following steps:

[0090] S101: Each columnar sub-module is used to process the third signal in parallel to obtain multiple beam sub-signals.

[0091] S102: Based on multiple beam sub-signals, a beam signal is formed.

[0092] The beam control module includes N columnar sub-modules.

[0093] Taking advantage of the parallel processing feature of the programmable logic unit, the beam control module is instantiated into N sub-modules to solve the array elements in different regions on the antenna extension. When the number of instantiated sub-modules is N, the processing time can be saved by N times. Meanwhile, data is processed in a pipelined manner within the sub-module, and the phase information of one array element can be solved in each clock cycle. Through these two methods, it only takes microseconds or even nanoseconds to complete one beam calculation, which can improve the calculation efficiency compared with the traditional CPU calculation method.

[0094] As Figure 4 shown, the antenna extension 1 includes an antenna array surface 11, a power supply module 12, and a TR chip 13;

[0095] The antenna array surface 11 is used to receive and transmit signals in a specific direction in space, and synthesize the echo signals through the TR chip 13 to obtain a radio frequency signal, and send the radio frequency signal to the channel signal processing beam control extension; the power supply module 12 is used to supply power to the radar processing system.

[0096] The TR chip (Transmit / Receive, that is, the transmit / receive chip) is the core component in the radar signal processing system and is widely used in multiple fields such as radar, communication, and autonomous driving. The TR chip is responsible for amplifying the signals transmitted by the radar and sending them to the antenna, and at the same time receiving the echo signals reflected from the target. The TR chip can precisely control the amplitude and phase of the signals, thereby realizing beam shaping and scanning. The TR chip is built-in with a transmit-receive switch and can quickly switch between the transmit and receive modes. In the transmit mode, the power amplifier of the TR chip amplifies the signal to sufficient power; in the receive mode, the low-noise amplifier (LNA) amplifies the weak echo signal while maintaining low noise. The TR chip usually integrates functions such as digital phase shifters and numerically controlled attenuators and supports control through a serial interface.

[0097] Electromagnetic wave signals are transmitted and received through the antenna array surface in the antenna extension, and signals are synthesized through the antenna array surface and the TR chip. After synthesis, the data of each channel realizes the "sum-difference-difference" three-way radio frequency signals required by the radar signal through a passive device and-differencer.

[0098] For example: adding the signals received by the antenna array surface to form a "sum" signal for target detection and distance measurement. Forming a "difference" signal through subtraction for target angle measurement and beam control. Through the design of the and-differencer, the output of the "sum-difference-difference" three-way radio frequency signals can be realized to meet the measurement requirements of the radar signal processing system for different directions and angles.

[0099] As shown Figure 5 in the figure, it is a schematic diagram of the signal processing flow of the integrated channel module, including the following steps:

[0100] S201: Perform frequency synthesis processing on the radio frequency signal to obtain the first radio frequency signal.

[0101] S202: Perform programmable filtering and frequency conversion processing on the first radio frequency signal to obtain an intermediate frequency signal.

[0102] S203: Use the intermediate frequency signal as the first signal.

[0103] The radio frequency signal is transmitted to the channel signal wave control branch through a waveguide. The radio frequency signal is subjected to frequency synthesis processing through the integrated channel module, and after programmable filtering and frequency conversion, the radio frequency signal is converted into an intermediate frequency signal.

[0104] As shown Figure 6 in the figure, it is a schematic diagram of the preprocessing flow of the signal sampling and baseband processing module, including the following steps:

[0105] S301: Sample the echo signal through an analog-to-digital converter and convert it into a digital signal.

[0106] S302: Filter the digital signal based on a filter to obtain a filtered digital signal.

[0107] S303: Decimate the filtered digital signal according to a preset ratio to obtain a second digital signal.

[0108] S304: Determine the delay parameter of the filter, and compensate the second digital signal based on the delay parameter to obtain the signal after preprocessing the first signal.

[0109] The echo signal is first sampled through an analog-to-digital converter and converted into a digital signal. Design a suitable filter according to the frequency characteristics of the signal, such as a FIR filter or an IIR filter. The FIR filter is widely used due to its linear phase characteristics and stability. The signal is filtered through the filter to remove high-frequency noise or clutter components, and then the signal is decimated according to a certain ratio to reduce the sampling rate. Since the filter will introduce delay, it is necessary to compensate the delay of the signal to ensure the integrity of the signal.

[0110] As shown Figure 7 in the figure, it is a schematic diagram of the pulse compression process of the signal sampling and baseband processing module, including the following steps:

[0111] S401: Perform optimal matched filtering processing on the signal after preprocessing the first signal to obtain a first filtered signal.

[0112] S402: Phase-coherently synthesize the first filtered signal in the time domain to obtain the signal after pulse compression processing of the signal preprocessed from the first signal.

[0113] Optimal matched filtering is a filtering technique based on a signal template. Its core is to use the time reversal of the transmitted signal as the impulse response of the filter, thereby maximizing the signal-to-noise ratio of the output signal. The specific steps are as follows: Obtain the template s(t) of the transmitted signal. Construct the impulse response h(t) of the matched filter as h(t) = s(T - t), where T is the signal duration. Convolve the received signal r(t) with the filter coefficient h(t) to obtain the output signal y(t). Find the peak position in the output signal to determine the presence and parameters of the target.

[0114] The design of the matched filter needs to consider the actual characteristics of the signal, such as bandwidth, time delay, etc., to ensure optimal performance.

[0115] Phase-coherent synthesis is to process the signal in the time domain or frequency domain to accumulate the energy of the signal, thereby improving the signal-to-noise ratio and detection performance. For a linear frequency modulation (LFM) signal, the following steps are usually adopted: Use a matched filter to perform pulse compression on the LFM signal to make the target echo energy more concentrated in the time domain. In the frequency domain, correct the phase of the signal through phase compensation (such as multiplying by a reference function) to avoid phase errors caused by Doppler frequency shift or range migration. Incoherently or coherently accumulate the processing results of multiple pulses to further improve the signal-to-noise ratio.

[0116] Signal processing gain accumulation is to accumulate the processing results of multiple pulses, thereby improving the detection ability of the system. The specific methods include: Accumulate the amplitudes or powers of multiple pulses, which is applicable to scenarios where the target speed changes greatly. Accumulate the phases of multiple pulses after correction, which is applicable to scenarios where the target speed changes slightly.

[0117] Range migration compensation is to correct the signal offset caused by the movement of a moving target or the radar platform. Common methods include:

[0118] Interpolation method: Resample the signal in the time domain or range-Doppler domain to directly move the position of the signal.

[0119] Frequency-domain phase compensation: Compensate for range migration in the frequency domain through phase multiplication to avoid explicit resampling operations.

[0120] Chirp-Z transform: Process the signal after pulse compression through the Chirp-Z transform to compensate for the range migration of the target.

[0121] Through optimal matching filtering, phase coherent synthesis, signal processing gain accumulation, and range migration compensation, the radar system can achieve high-precision target detection and imaging in complex environments.

[0122] This application also provides a radar signal processing method, which processes the received radar signals through the radar signal processing system.

[0123] In the embodiments provided in this application, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architectures, functions, and operations of devices, methods, and computer program products according to multiple embodiments of this application. In this regard, each block in the flowchart or block diagram may represent a module, a program segment, or a part of code, and the module, program segment, or part of code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than marked in the accompanying drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, and the combination of blocks in the block diagram and / or flowchart, can be implemented by a dedicated hardware-based system for performing the specified functions or actions, or can be implemented by a combination of dedicated hardware and computer instructions.

[0124] In addition, the functional modules in each embodiment of this application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part. If the functions are implemented in the form of software functional modules and sold or used as an independent product, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in each embodiment of this application. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical discs that can store program codes.

[0125] It should be noted that, in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the said element.

[0126] As described above, the above are only various embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A radar signal processing system, characterized in that: The system comprises: an antenna extension and a channel signal processing and beam control extension, wherein the channel signal processing and beam control extension comprises an integrated channel module, a signal sampling and baseband processing module, an information processing module and a beam control module; The antenna extension is used to receive the echo signal, obtain a radio frequency signal based on the received echo signal, and send the radio frequency signal to the channel signal processing and wave control extension; The integrated channel module is used to perform frequency synthesis and filtering processing on the radio frequency signal to obtain a first signal; The signal sampling and baseband processing module is used to perform preprocessing, pulse compression processing, MTD processing and CFAR processing on the first signal in sequence to obtain a second signal; The information processing module is used to perform speed calculation, distance prediction, angle filtering, track association and strapdown descrambling on the second signal to obtain a third signal; The beam control module is used to perform beamforming on the third signal to obtain a beam signal, and send the beam signal to the antenna extension.

2. The system according to claim 1, characterized in that The system also includes a SOC chip; The SOC chip includes a programmable logic unit and an ARM processor; The signal sampling and baseband processing module and the beam control module are integrated in the programmable logic unit; The information processing module is integrated in the ARM processor.

3. The system according to claim 2, characterized in that The programmable logic unit includes a timing control module; The timing control module is used to control the working status of the signal sampling and baseband processing module, the information processing module and the beam control module to control the processing process synchronization of the signal sampling and baseband processing module, the information processing module and the beam control module.

4. The system according to claim 2, characterized in that The programmable logic unit and the ARM processor are communicatively connected via an AXI bus.

5. The system according to claim 1, characterized in that The beam control module includes N columnized submodules; Each of the columnization submodules is used to process the third signal in parallel to obtain a plurality of beam sub-signals; A beam signal is constructed based on a plurality of beam sub-signals.

6. The system according to claim 1, characterized in that The antenna extension includes an antenna array, a power module and a TR chip; The antenna array is used to receive and transmit signals in a specific direction in space, and synthesize the echo signal through the TR chip to obtain a radio frequency signal, and send the radio frequency signal to the channel signal processing wave control extension; The power supply module is used to supply power to the radar signal processing system.

7. The system according to claim 1, characterized in that The integrated channel module is specifically used for: Performing frequency synthesis processing on the radio frequency signal to obtain a first radio frequency signal; The first radio frequency signal is subjected to programmable filtering and frequency conversion processing to obtain an intermediate frequency signal; The intermediate frequency signal is used as the first signal.

8. The system according to claim 1, characterized in that The pre-processing comprises: The echo signal is sampled by an analog-to-digital converter and converted into a digital signal; Filtering the digital signal based on a filter to obtain a filtered digital signal; Extracting the filtered digital signal according to a preset ratio to obtain a second digital signal; A delay parameter of the filter is determined, and the second digital signal is compensated based on the delay parameter to obtain a signal obtained by preprocessing the first signal.

9. The system according to claim 8, characterized in that The pulse compression comprises: Performing optimal matched filtering on the signal after the first signal preprocessing to obtain a first filtered signal; The first filtered signal is phase-coherently synthesized in the time domain to obtain a signal obtained by pulse compression processing of the signal preprocessed by the first signal.

10. A radar signal processing method, characterized in that: The received radar signal is processed by the radar signal processing system according to any one of claims 1 to 9.

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