Multi-mode adaptive phase coding radar and speed ambiguity resolution technology

Abstract

The invention discloses a multi-mode adaptive phase coding radar and a speed ambiguity resolution technology, and relates to the technical field of millimeter wave radars, and the radar comprises a radar signal processing system, a multi-mode adaptive control module, an adaptive phase coding module, a frequency modulation module, a PRF optimization module, a PMCW waveform generator, and a speed ambiguity resolution algorithm module. According to the multi-mode self-adaptive phase coding radar and the speed ambiguity resolution technology, the performance of a radar system is remarkably improved by integrating PRF optimization, phase coding integration and frequency modulation methods, the problem of speed ambiguity in high-speed target detection can be effectively solved, the accuracy of speed measurement and the maximum measurable speed are improved, and meanwhile, the speed ambiguity resolution technology can be applied to the field of high-speed target detection. According to the invention, the anti-interference capability and the multi-target separation capability of the radar in a complex environment are enhanced, high-precision and high-efficiency target detection and tracking are realized, and in addition, the multi-mode adaptive function enables the radar system to flexibly meet the detection requirements in different scenes.

Description

Technical Field

[0001] The present invention relates to the technical field of millimeter wave radars, and in particular to a multi-mode adaptive phase coding radar and a speed deambiguation technology. Background Art

[0002] Millimeter-wave radar is widely used in fields such as autonomous driving, traffic monitoring, and aerospace due to its good penetration, anti-interference ability, and high resolution. With the continuous development of technology, higher requirements are placed on the radar system's target detection accuracy, speed measurement range, and multi-target processing capabilities.

[0003] PRF (Pulse Repetition Frequency) is a key parameter in radar systems, which directly affects the accuracy of speed measurement and the maximum measurable speed;

[0004] Although traditional millimeter-wave radar has advantages such as strong penetration and good anti-interference ability in target detection and speed measurement, in actual use, due to the limitation of PRF, it is easy to encounter the problem of speed detection ambiguity in high-speed moving target detection, resulting in increased speed measurement errors. At the same time, for multi-target detection in complex environments, the resolution and anti-interference ability of traditional millimeter-wave radar are limited, making it difficult to achieve high-precision and high-efficiency target separation and tracking. Summary of the invention

[0005] The object of the present invention is to provide a multi-mode adaptive phase coding radar and a velocity deambiguation technology to solve the problems raised in the above background technology.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a multi-mode adaptive phase coding radar and speed deambiguation technology, including a radar signal processing system, a multi-mode adaptive control module, an adaptive phase coding module, a frequency modulation module, a PRF optimization module, a PMCW waveform generator, and a speed deambiguation algorithm module. The radar signal processing system is the core link of the entire system, which is used to provide basic data for other modules, is responsible for receiving and processing radar echo signals, and extracts target information to provide basic data for speed deambiguation and target detection. The echo signal denoising processing formula is: xk=Axk-1+Buk+wk, wherein xk represents the current state estimate, A is the state transfer matrix, xk-1 is the state estimate at the previous moment, B is the control input matrix, uk is the control input, and wk is the process noise; the multi-mode adaptive control module is used to automatically switch the radar's working mode according to real-time environmental changes and target characteristics; the adaptive phase coding module is used to generate and adjust the phase coding sequence, modulate the radar transmit waveform, and adjust the radar's operating mode according to different working modes and target characteristics. , automatically adjust the phase coding parameters, work closely with the PMCW waveform generator, apply the generated phase coding sequence to the radar transmission waveform, and work with the multi-mode adaptive control module to ensure that the phase coding sequence matches the current working mode; the frequency modulation module is used to adjust the frequency parameters of the radar transmission waveform, work closely with the multi-mode adaptive control module and the PMCW waveform generator, adjust the frequency parameters according to the instructions of the control module, and pass the adjusted frequency information to the PMCW waveform generator to generate the corresponding transmission waveform; the PRF optimization module is used to optimize the pulse repetition frequency of the radar according to the speed and distance information of the target; the PMCW waveform generator is used to generate a specific pulse modulated continuous wave (PMCW) waveform, and generate the corresponding transmission waveform according to the instructions of the multi-mode adaptive control module, the adaptive phase coding module and the frequency modulation module; the speed deambiguation algorithm module receives the echo signal from the radar signal processing system and the PRF information of the PRF optimization module as input data, and is responsible for processing the Doppler frequency shift information in the radar echo signal.

[0007] Preferably, the radar signal processing system includes a signal preprocessing unit and a feature extraction unit. The signal preprocessing unit is responsible for filtering, denoising and other processing on the received radar echo signal to improve the signal quality. The feature extraction unit is responsible for extracting key information such as the target distance, speed, angle and so on from the processed signal to provide accurate data support for subsequent speed deambiguation and target detection. The signal preprocessing uses an algorithm: for a signal sequence x1, x2, ..., xn with a length of n, the output yi after median filtering is: yi = median{x(i-(k-1) / 2), ..., xi, ..., x(i+k / 2)}, where k is the filter window size, the distance calculation formula is: R = cT / 2, where R is the target distance, c is the speed of light, and T is the signal round-trip time. The speed extraction uses the Doppler effect formula: v = cΔf / (2f0cosθ), where v is the target speed, c is the speed of light, Δf is the Doppler frequency shift, f0 is the transmission frequency, and θ is the angle between the target and the radar line and the radar beam direction.

[0008] Preferably, the multi-mode switching module includes a high-speed moving target mode, a long-distance target mode, and a multi-target mode.

[0009] Preferably, in the long-distance target mode, the multi-mode switching module uses a long code sequence or a low coding rate in the adaptive phase coding module, the frequency modulation module reduces the attenuation of the signal during propagation by lowering the transmission frequency, and the PRF optimization module automatically adjusts the pulse repetition frequency according to the target distance, and calculates the attenuation formula of the signal in long-distance transmission: Pr=PtGtGrλ2 / (4πR)2, wherein Pr is the received power, Pt is the transmitted power, Gt is the transmitting antenna gain, Gr is the receiving antenna gain, λ is the wavelength, and R is the target distance.

[0010] Preferably, in the high-speed moving target mode, the multi-mode switching module, the adaptive phase encoding module and the frequency modulation module work together to generate a high-frequency changing phase encoding sequence and a corresponding high-frequency transmission waveform, and the PRF optimization module automatically adjusts the pulse repetition frequency according to the expected speed of the high-speed target.

[0011] Preferably, in the multi-target mode, the multi-mode switching module dynamically adjusts the radar's operating mode and parameters according to the multiple target information in the radar echo signal, the adaptive phase coding module generates a complex phase coding sequence, and the speed deambiguation algorithm module adopts advanced algorithms, such as multiple PRF technology or spectrum analysis methods, to parse and distinguish the speed information of multiple targets, thereby achieving accurate speed measurement of multiple targets.

[0012] Preferably, the waveform generated by the PMCW waveform generator has the characteristics of high average power and short pulse width.

[0013] Preferably, an intelligent learning module is included to automatically optimize the radar's operating mode and parameter settings based on historical data and real-time feedback, including the generation strategy of the phase coding sequence, the adjustment rules of the frequency modulation parameters, and the selection of the PRF optimization algorithm.

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

[0015] The present invention describes a multi-mode adaptive phase coding radar and velocity deambiguation technology:

[0016] 1. The present invention can enhance environmental adaptability and target detection capabilities. By introducing a multi-mode adaptive control module, the radar system can automatically switch working modes (such as high-speed moving target mode, long-distance target mode, multi-target mode, etc.) according to real-time environmental changes and target characteristics. This adaptive adjustment capability significantly enhances the working performance of the radar under different environments and conditions, and improves the accuracy and reliability of target detection.

[0017] 2. The present invention can improve the speed measurement accuracy and speed deambiguation capability. By combining the adaptive phase encoding module, the frequency modulation module and the PRF optimization module, the optimized transmission waveform and pulse repetition frequency are generated for high-speed or long-distance targets, thereby effectively reducing the speed ambiguity phenomenon and improving the speed measurement accuracy. The introduction of the speed deambiguation algorithm module further enhances the radar system's ability to process complex Doppler frequency shift information, ensuring that the speed of each target can be accurately analyzed and distinguished in a multi-target environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the system structure of the present invention. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] See also Figure 1 , the present invention provides a technical solution:

[0021] A multi-mode adaptive phase coding radar and speed deambiguation technology, including a radar signal processing system, a multi-mode adaptive control module, an adaptive phase coding module, a frequency modulation module, a PRF optimization module, a PMCW waveform generator, and a speed deambiguation algorithm module. The radar signal processing system is the core link of the entire system, which is used to provide basic data for other modules, is responsible for receiving and processing radar echo signals, and extracting target information to provide basic data for speed deambiguation and target detection. The echo signal denoising processing formula is: xk=Axk-1+Buk+wk, wherein xk represents the current state estimation value, A is the state transfer matrix, xk-1 is the state estimation value at the previous moment, B is the control input matrix, uk is the control input, and wk is the process noise; the multi-mode adaptive control module is used to automatically switch the radar working mode according to real-time environmental changes and target characteristics; the adaptive phase coding module is used to generate and adjust the phase coding sequence, modulate the radar transmission waveform, and automatically adjust the phase coding parameter according to different working modes and target characteristics. The module is used to adjust the frequency parameters of the radar transmission waveform, and closely cooperates with the multi-mode adaptive control module and the PMCW waveform generator to adjust the frequency parameters according to the instructions of the control module, and transmits the adjusted frequency information to the PMCW waveform generator to generate the corresponding transmission waveform; the PRF optimization module is used to optimize the pulse repetition frequency of the radar according to the speed and distance information of the target; the PMCW waveform generator is used to generate a specific pulse modulated continuous wave (PMCW) waveform, and generates the corresponding transmission waveform according to the instructions of the multi-mode adaptive control module, the adaptive phase coding module and the frequency modulation module; the speed deambiguation algorithm module receives the echo signal from the radar signal processing system and the PRF information of the PRF optimization module as input data, and is responsible for processing the Doppler frequency shift information in the radar echo signal.

[0022] The radar signal processing system includes a signal preprocessing unit and a feature extraction unit. The signal preprocessing unit is responsible for filtering and denoising the received radar echo signal to improve the signal quality. The feature extraction unit is responsible for extracting key information such as the target's distance, speed, angle, etc. from the processed signal to provide accurate data support for subsequent speed deambiguation and target detection. The signal preprocessing uses an algorithm: for a signal sequence x1, x2, ..., xn with a length of n, the output yi after median filtering is: yi = median{x(i-(k-1) / 2), ..., xi, ..., x(i+k / 2)}, where k is the filter window size, the distance calculation formula is: R = cT / 2, where R is the target distance, c is the speed of light, and T is the signal round-trip time. The speed extraction formula using the Doppler effect is: v = cΔf / (2f0cosθ), where v is the target speed, c is the speed of light, Δf is the Doppler frequency shift, f0 is the transmission frequency, and θ is the angle between the target and radar line and the radar beam direction.

[0023] The multi-mode switching module includes high-speed moving target mode, long-distance target mode, and multi-target mode.

[0024] In the long-distance target mode, the multi-mode switching module uses a long code sequence or a low coding rate in the adaptive phase coding module, and the frequency modulation module reduces the attenuation of the signal during the propagation process by lowering the transmission frequency. The PRF optimization module automatically adjusts the pulse repetition frequency according to the target distance and calculates the attenuation formula of the signal in long-distance transmission: Pr=PtGtGrλ2 / (4πR)2, where Pr is the received power, Pt is the transmitted power, Gt is the transmitting antenna gain, Gr is the receiving antenna gain, λ is the wavelength, and R is the target distance.

[0025] In the high-speed moving target mode, the adaptive phase encoding module and the frequency modulation module work together to generate a high-frequency phase encoding sequence and a corresponding high-frequency transmission waveform. The PRF optimization module automatically adjusts the pulse repetition frequency according to the expected speed of the high-speed target.

[0026] In the multi-target mode, the multi-mode switching module dynamically adjusts the radar's operating mode and parameters according to the multiple target information in the radar echo signal. The adaptive phase coding module generates a complex phase coding sequence. The speed deambiguation algorithm module uses advanced algorithms, such as multiple PRF technology or spectrum analysis methods, to parse and distinguish the speed information of multiple targets, thereby achieving accurate speed measurement of multiple targets.

[0027] The waveform generated by the PMCW waveform generator has the characteristics of high average power and short pulse width.

[0028] It includes an intelligent learning module that automatically optimizes the radar's operating mode and parameter settings based on historical data and real-time feedback, including the generation strategy of the phase coding sequence, the adjustment rules of the frequency modulation parameters, and the selection of the PRF optimization algorithm.

[0029] Working principle:

[0030] When in use, the radar signal processing system, as the core link, receives and processes the radar echo signal. First, the signal preprocessing unit filters and denoises the received echo signal to improve the signal quality. Then, the feature extraction unit extracts the target's distance, speed, angle and other key information from the processed signal to provide accurate data support for subsequent speed deambiguation and target detection. The multi-mode adaptive control module automatically switches the radar's working mode according to real-time environmental changes and target characteristics. The adaptive phase coding module works closely with the PMCW waveform generator to generate and adjust the phase coding sequence according to different working modes and modulate the radar transmission waveform. The frequency modulation module also works closely with the multi-mode adaptive control module and the PMCW waveform generator to adjust the frequency parameters of the radar transmission waveform according to the instructions of the control module, and pass the adjusted frequency information to the PMCW waveform generator to generate the corresponding transmission waveform. The PRF optimization module optimizes the radar's pulse repetition frequency according to the target's speed and distance information. The speed deambiguation algorithm module receives the echo signal from the radar signal processing system and the PRF information from the PRF optimization module, and is responsible for processing the Doppler frequency shift information in the radar echo signal;

[0031] After receiving the radar echo signal, the signal preprocessing unit in the radar signal processing system uses various filtering algorithms to remove the noise in the signal and improves the signal-to-noise ratio through denoising. Then, the feature extraction unit uses signal processing techniques, such as pulse compression and Doppler processing, to accurately extract the distance information of the target from the processed signal and determine the distance between the target and the radar by analyzing the time delay of the echo signal. For the extraction of speed information, the Doppler effect is used to calculate the relative speed of the target according to the frequency change of the echo signal. The angle information is determined by the beamforming technology of the antenna array according to the phase difference of the received signals of different antennas to determine the azimuth of the target. The extracted target information provides the data basis for the subsequent speed deambiguation and target detection.

[0032] The multi-mode switching module includes high-speed moving target mode, long-distance target mode and multi-target mode. In different modes, the various modules of the system will work together to adapt to specific target detection requirements; for example, when the system switches to high-speed moving target mode, the adaptive phase coding module and the frequency modulation module work together to generate a high-frequency changing phase coding sequence and a corresponding high-frequency transmission waveform to better track high-speed moving targets. The PRF optimization module automatically adjusts the pulse repetition frequency according to the expected speed of the high-speed target to ensure that the speed of the high-speed target can be accurately measured and the speed ambiguity can be reduced. In the long-distance target mode, the adaptive phase coding module uses a long code sequence or a low coding rate to increase the signal penetration ability and echo strength. The frequency modulation module reduces the attenuation of the signal during propagation by reducing the transmission frequency. The PRF optimization module automatically adjusts the pulse repetition frequency according to the target distance to ensure that the target can be effectively detected at a long distance. In the multi-target mode, according to the multiple target information in the radar echo signal, the multi-mode adaptive control module dynamically adjusts the radar's working mode and parameters. The adaptive phase encoding module generates complex phase encoding sequences to distinguish different targets. The speed deambiguation algorithm module uses advanced algorithms, such as multiple PRF technology or spectrum analysis methods, to parse and distinguish the speed information of multiple targets and achieve accurate speed measurement of multiple targets.

[0033] In the long-distance target mode, the multi-mode switching module first triggers the mode according to the distance characteristics of the target. At this time, the adaptive phase coding module uses a long code sequence or a low coding rate, which can make the transmitted signal more stable and anti-interference during the propagation process. When the signal reaches the long-distance target and returns, the long code sequence can provide more information, which is convenient for the radar signal processing system to better identify the target. The frequency modulation module reduces the transmission frequency, because the lower frequency attenuates relatively less during the propagation process, which can ensure that the signal is still strong enough to be received after long-distance transmission. The PRF optimization module automatically adjusts the pulse repetition frequency according to the target distance to ensure that the target can be effectively detected at a long distance, while avoiding measurement errors caused by improper pulse repetition frequency. The PMCW waveform generator generates a pulse modulated continuous wave waveform suitable for long-distance target detection according to the instructions of the multi-mode adaptive control module, the adaptive phase coding module and the frequency modulation module. The waveform has a specific pulse width and repetition period to meet the detection requirements of long-distance targets;

[0034] When the system detects a high-speed moving target, the multi-mode switching module switches to the high-speed moving target mode. The adaptive phase coding module and the frequency modulation module work closely together to generate a high-frequency phase coding sequence and a corresponding high-frequency transmission waveform. The high-frequency phase coding sequence can better adapt to the rapid change characteristics of high-speed moving targets and improve the tracking accuracy of the target. The frequency modulation module generates a high-frequency transmission waveform, allowing the radar to more accurately measure the Doppler shift of the target. The PRF optimization module automatically adjusts the pulse repetition frequency according to the expected speed of the high-speed target to ensure that the speed of the high-speed target can be accurately measured and reduce speed ambiguity. After receiving the echo signal, the radar signal processing system uses a specific algorithm in the high-speed moving target mode to process it and extract the target's accurate speed, distance and angle information;

[0035] In the multi-target mode, the radar signal processing system first detects the echo signals of multiple targets. The multi-mode switching module dynamically adjusts the radar's operating mode and parameters based on the multiple target information in these echo signals. The adaptive phase encoding module generates a complex phase encoding sequence. Each target corresponds to a unique phase encoding to distinguish different targets. The speed deambiguation algorithm module uses advanced algorithms, such as multiple PRF technology or spectrum analysis methods, to process the echo signal. By analyzing the Doppler frequency shift information of different targets and combining the pulse repetition frequency information provided by the PRF optimization module, it parses and distinguishes the speed information of multiple targets to achieve accurate speed measurement of multiple targets. At the same time, the PMCW waveform generator generates a transmission waveform that can adapt to the detection of multiple targets at the same time according to the requirements of the multi-target mode.

[0036] The PMCW waveform generator generates a specific pulse modulated continuous wave waveform according to the instructions of the multi-mode adaptive control module, the adaptive phase coding module and the frequency modulation module. It has the characteristics of high average power and short pulse width. The high average power enables the radar to provide sufficient energy when transmitting the signal to ensure that the signal can reach the distant target or penetrate the complex environment during the propagation process. The short pulse width improves the distance resolution and can more accurately determine the location of the target. In different working modes, the PMCW waveform generator will adjust the waveform parameters such as pulse width, repetition period, phase coding sequence and frequency modulation parameters according to the instructions of each module to generate a transmission waveform that meets the specific target detection needs;

[0037] The intelligent learning module automatically optimizes the radar's operating mode and parameter settings based on historical data and real-time feedback. First, the intelligent learning module collects historical data of the radar in different working scenarios, including the characteristics of various targets, environmental conditions, and the performance of the radar system. By analyzing these historical data, the intelligent learning module summarizes the best parameter setting strategies under different situations; for example, for specific types of targets and environments, the optimal phase coding sequence generation strategy, frequency modulation parameter adjustment rules, and PRF optimization algorithm selection are determined. During the operation of the radar, the intelligent learning module receives feedback information from the radar signal processing system and other modules in real time. Based on these feedbacks, the intelligent learning module continuously adjusts the radar's operating mode and parameters to adapt to the changing targets and environment. For example, if it is found that the current parameter settings lead to inaccurate target detection or poor velocity deambiguation, the intelligent learning module will automatically adjust the corresponding parameters to improve the performance of the radar system.

[0038] Echo signal denoising processing formula calculation:

[0039] Assume that the state estimate x(k-1) at the previous moment is 5, the state transfer matrix A is 0.8, the control input matrix B is 0.5, the control input u(k) is 2, and the process noise w(k) is assumed to be 1 this time.

[0040] First, calculate the state prediction value: A*x(k-1)=0.8*5=4,

[0041] Consider the influence of control input: A*x(k-1)+B*u(k)=4+0.5*2=5,

[0042] Add process noise to get the current state estimate: x(k)=A*x(k-1)+B*u(k)+w(k)=5+1=6;

[0043] Median filtering and distance and speed calculation formula:

[0044] Median filter calculation: Assume that the signal sequence is [2,4,6,8,10] and the filter window size k is 3. For the middle point i=2 (corresponding value is 6), the sequence in the window is [4,6,8] and the median is 6, so y(2)=6 at this time.

[0045] Distance calculation formula: Assume that the speed of light c = 3 × 10^8 m / s, and the signal round trip time T = 0.001 s,

[0046] According to the formula R = cT / 2 = (3 × 10^8) × 0.001 / 2 = 150000m,

[0047] Velocity extraction Doppler effect formula calculation: Assume that the speed of light c = 3 × 10^8 m / s, Doppler frequency shift Δf = 1000 Hz, transmission frequency f0 = 10 GHz = 10 × 10^9 Hz, the angle between the target and radar line and the radar beam direction θ = 30°,

[0048] First calculate cosθ=cos(30°)≈0.866,

[0049] Substituting into the formula, we can get v = cΔf / (2f0cosθ) = (3×10^8)×1000 / (2×10×10^9×0.866)≈17.32m / s;

[0050] Long distance transmission attenuation calculation formula:

[0051] Assume that the transmission power P(t) = 100W, the transmission antenna gain G(t) = 10, the receiving antenna gain G(r) = 8, the wavelength λ = 0.1m, and the target distance R = 1000m.

[0052] Substitute the formula to calculate the received power: P(r)=P(t)*G(t)*G(r)*λ2 / (4πR)2=100×10×8×0.12 / (4π×1000)2≈6.37×10-7W.

[0053] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A multi-mode adaptive phase coding radar and speed deambiguation technology, comprising a radar signal processing system, a multi-mode adaptive control module, an adaptive phase coding module, a frequency modulation module, a PRF optimization module, a PMCW waveform generator, and a speed deambiguation algorithm module, characterized in that: The radar signal processing system is the core link of the whole system, which is used to provide basic data for other modules, is responsible for receiving and processing radar echo signals, extracting target information to provide basic data for velocity deambiguation and target detection, and the echo signal denoising processing formula is: xk=Axk-1+Buk+wk, where xk represents the current state estimate, A is the state transfer matrix, xk-1 is the state estimate at the previous moment, B is the control input matrix, uk is the control input, and wk is the process noise; the multi-mode adaptive control module is used to automatically switch the working mode of the radar according to real-time environmental changes and target characteristics; the adaptive phase coding module is used to generate and adjust the phase coding sequence, modulate the radar transmission waveform, and automatically adjust the phase coding parameters according to different working modes and target characteristics. It works closely with the PMCW waveform generator to apply the generated phase coding sequence to the radar transmission waveform, and works in coordination with the multi-mode adaptive control module to ensure that the phase coding sequence matches the current working mode; The frequency modulation module is used to adjust the frequency parameters of the radar transmission waveform. It works closely with the multi-mode adaptive control module and the PMCW waveform generator to adjust the frequency parameters according to the instructions of the control module and pass the adjusted frequency information to the PMCW waveform generator to generate the corresponding transmission waveform. The PRF optimization module is used to optimize the pulse repetition frequency of the radar according to the speed and distance information of the target; the PMCW waveform generator is used to generate a specific pulse modulated continuous wave (PMCW) waveform and generate the corresponding transmission waveform according to the instructions of the multi-mode adaptive control module, the adaptive phase coding module and the frequency modulation module; the speed deambiguation algorithm module receives the echo signal from the radar signal processing system and the PRF information of the PRF optimization module as input data, and is responsible for processing the Doppler frequency shift information in the radar echo signal.

2. The multi-mode adaptive phase coded radar and velocity deambiguation technology according to claim 1, characterized in that: The radar signal processing system includes a signal preprocessing unit and a feature extraction unit. The signal preprocessing unit is responsible for filtering and denoising the received radar echo signal to improve the signal quality. The feature extraction unit is responsible for extracting key information such as the distance, speed, angle, etc. of the target from the processed signal to provide accurate data support for subsequent speed deambiguation and target detection. The signal preprocessing uses an algorithm: for a signal sequence x1, x2, ..., xn with a length of n, the output yi after median filtering is: yi = median{x(i-(k-1) / 2), ..., xi, ..., x(i+k / 2)}, where k is the filter window size, the distance calculation formula is: R = cT / 2, where R is the target distance, c is the speed of light, and T is the signal round-trip time. The speed extraction uses the Doppler effect formula: v = cΔf / (2f0cosθ), where v is the target speed, c is the speed of light, Δf is the Doppler frequency shift, f0 is the transmission frequency, and θ is the angle between the target and the radar connection line and the radar beam direction.

3. The multi-mode adaptive phase coded radar and velocity deambiguation technology according to claim 1, characterized in that: The multi-mode switching module includes a high-speed moving target mode, a long-distance target mode, and a multi-target mode.

4. The multi-mode adaptive phase coded radar and velocity deambiguation technology according to claim 3, characterized in that: In the long-distance target mode, the multi-mode switching module uses a long code sequence or a low coding rate in the adaptive phase coding module, and the frequency modulation module reduces the attenuation of the signal during the propagation process by lowering the transmission frequency. The PRF optimization module automatically adjusts the pulse repetition frequency according to the target distance, and calculates the attenuation formula of the signal in long-distance transmission: Pr=PtGtGrλ2 / (4πR)2, where Pr is the received power, Pt is the transmitted power, Gt is the transmitting antenna gain, Gr is the receiving antenna gain, λ is the wavelength, and R is the target distance.

5. The multi-mode adaptive phase coded radar and velocity deambiguation technology according to claim 3, characterized in that: In the high-speed moving target mode, the multi-mode switching module, the adaptive phase encoding module and the frequency modulation module work together to generate a high-frequency phase encoding sequence and a corresponding high-frequency transmission waveform, and the PRF optimization module automatically adjusts the pulse repetition frequency according to the expected speed of the high-speed target.

6. The multi-mode adaptive phase coded radar and velocity deambiguation technology according to claim 1, characterized in that: In the multi-target mode, the multi-mode switching module dynamically adjusts the radar's operating mode and parameters according to the multiple target information in the radar echo signal. The adaptive phase coding module generates a complex phase coding sequence. The speed deambiguation algorithm module uses advanced algorithms, such as multiple PRF technology or spectrum analysis methods, to parse and distinguish the speed information of multiple targets, thereby achieving accurate speed measurement of multiple targets.

7. The multi-mode adaptive phase coded radar and velocity deambiguation technology according to claim 1, characterized in that: The waveform generated by the PMCW waveform generator has the characteristics of high average power and short pulse width.

8. The multi-mode adaptive phase coded radar and velocity deambiguation technology according to claim 1, characterized in that: It includes an intelligent learning module that automatically optimizes the radar's operating mode and parameter settings based on historical data and real-time feedback, including the generation strategy of the phase coding sequence, the adjustment rules of the frequency modulation parameters, and the selection of the PRF optimization algorithm.

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