A method and device for calculating a diagonal loading quantity of sidelobe cancellation and a storage medium

Abstract

The application provides a sidelobe cancellation diagonal loading quantity calculation method, comprising the following steps: calculating a theoretical noise power through a system noise temperature, and calculating a first diagonal loading quantity according to the theoretical noise power; calculating a current noise power of the system through an actual echo signal, and determining a second diagonal loading quantity according to the current noise power; taking a smaller value of the first diagonal loading quantity and the second diagonal loading quantity as a current diagonal loading quantity; updating the second diagonal loading quantity in real time according to the current noise power of the system, and when the updated second diagonal loading quantity is greater than the current diagonal loading quantity, taking the first diagonal loading quantity as the current diagonal loading quantity; otherwise, taking the updated second diagonal loading quantity as the current diagonal loading quantity. Through dynamic updating of the diagonal loading quantity according to the real-time echo signal state, the performance of the sidelobe cancellation algorithm can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of radar signal processing, and particularly relates to a method, device and storage medium for calculating the diagonal loading amount of sidelobe cancellation. Background Art

[0002] Sidelobe cancellation (SLC) is an important anti-jamming means for radar sidelobes. During the solution process of the weighted vector W of the sidelobe cancellation open-loop algorithm, it is necessary to perform diagonal loading on the autocorrelation covariance matrix of the signal, that is, opt W opt =(R + γI)r xy . Diagonal loading refers to adding a diagonal matrix multiplied by a loading small amount to the autocorrelation covariance matrix of the signal to achieve the correction of the covariance matrix, which can avoid the matrix inverse operation error caused by the non-full rank of the covariance matrix.

[0003] The method of performing diagonal loading on the covariance matrix is relatively common in adaptive beamforming (ADBF), spatial spectrum estimation, and space-time adaptive processing, but the value-taking methods of the loading amount are relatively diverse. Some patents only give a certain value range. For example, in the domestic patent "CN 104360338 A", only γ>0 is required when doing ADBF, and the domestic patent "CN 103197325 B" requires that the loading amount should be less than the diagonal elements of the sampling signal covariance matrix, that is, γ<R(i,i). Some patents will give quantitative values. For example, in the domestic patent "CN 107544059A", when doing ADBF, the diagonal loading amount is the average noise energy; in the domestic patent "CN 114520755 A", when estimating the number of signal sources, first perform eigenvalue decomposition on the covariance matrix R to obtain the eigenvalue sequence The diagonal loading amount takes In the domestic patents "CN 114866122A" and "CN 112904289", the average of the eigenvalues corresponding to the noise subspace after eigenvalue decomposition is taken, that is, The value-taking in some patents depends on engineering experience. For example, in the domestic patent "CN 110196426A", γ = tr(R)×σ, σ∈[0.0001,0.1], and tr(·) represents the trace operation of the matrix; in the domestic patent "CN 103245941 A", M is the dimension of the matrix R, and γ0 is an empirical value used to measure the quality of the estimated data covariance matrix, generally taking 0.5 - 2.

[0004] The aforementioned patents primarily address the value of γ in relation to noise power, making accurate noise estimation crucial. A method of averaging the eigenvalues ​​corresponding to the noise subspace after eigenvalue decomposition of the covariance matrix R is a relatively good noise power estimation method when the number of sources is known. However, in SLC applications, the number of sources (interference sources) is usually unknown, and due to the limited number of SLC auxiliary channels, the dimension of R is low. Errors in estimating the number of sources significantly impact the value of γ, affecting the stability of engineering applications. In interference environments, the samples used to calculate noise power may be contaminated by interference samples, leading to a deviation between the calculated noise power and the actual noise power. Domestic patent "CN 107306244 B" considers a method for determining the loading amount under noise interference environments. Where P n P is the noise power. J This represents the interference power. However, if the duty cycle of the interference signal is high, it is usually difficult to separate the noise and interference and calculate their power separately. Summary of the Invention

[0005] To address the problem that the noise power of radar echo signals is difficult to calculate accurately under interference conditions, which in turn makes it difficult to select the sidelobe cancellation loading amount, a method, device, and storage medium for calculating the diagonal loading amount of sidelobe cancellation are provided. By dynamically updating the diagonal loading amount through real-time echo signal status, the performance of the sidelobe cancellation algorithm can be improved.

[0006] The first aspect of this invention proposes a method for calculating the diagonal loading amount of sidelobe cancellation, comprising:

[0007] The theoretical noise power is calculated by using the system's noise temperature, and the first diagonal loading amount is calculated based on the theoretical noise power.

[0008] The current noise power of the system is calculated using the actual echo signal, and the second diagonal loading amount is determined based on the current noise power.

[0009] Take the smaller value between the first diagonal loading amount and the second diagonal loading amount as the current diagonal loading amount;

[0010] The second diagonal loading amount is updated in real time based on the current noise power of the system. When the updated second diagonal loading amount is greater than the current diagonal loading amount, the first diagonal loading amount is used as the current diagonal loading amount; otherwise, the updated second diagonal loading amount is used as the current diagonal loading amount.

[0011] As a preferred embodiment, the theoretical noise power is calculated based on the system's noise bandwidth, noise temperature, and noise figure.

[0012] As a preferred option, when the system includes multiple transmitted signal waveforms, the noise bandwidth is taken as the maximum signal bandwidth among the bandwidths corresponding to different transmitted signal waveforms.

[0013] As a preferred embodiment, the theoretical noise power calculation formula is as follows:

[0014]

[0015] Among them, P n,max B is the theoretical noise power corresponding to the maximum signal bandwidth. sig,i Let i = 1, 2, ..., M be the bandwidth corresponding to the i-th transmitted signal waveform, k be the Boltzmann constant, and T be the bandwidth corresponding to the i-th transmitted signal waveform. s For noise temperature, N f This represents the noise figure.

[0016] As a preferred embodiment, the first diagonal loading amount is taken as a multiple of the theoretical noise power according to the 3σ criterion.

[0017] As a preferred embodiment, the current noise power calculation process of the system includes:

[0018] After the radar is started, the current noise power of the system is calculated based on partial data from each radar echo signal.

[0019] As a preferred embodiment, the method for calculating the second diagonal loading amount includes:

[0020]

[0021] Where, γ sig For the second diagonal loading amount, P n,sig Let be the current noise power of the system, and sig(n) be the nth data point of the echo signal. is the average value of the echo signal, and N is the length of the selected data portion.

[0022] A second aspect of the present invention provides an electronic device, including a memory and a processor, wherein the memory stores a computer program that can be loaded by the processor and executed corresponding to the sidelobe cancellation diagonal loading calculation method as described in the first aspect.

[0023] A third aspect of the present invention provides a computer-readable storage medium having stored computer program instructions thereon, characterized in that, when the program instructions are executed by a processor, they are used to implement the process corresponding to the sidelobe cancellation diagonal loading calculation method described in the first aspect.

[0024] Compared with existing technologies, the beneficial effects of adopting the above technical solution are as follows:

[0025] (1) In cases where the interference fails to cover the entire echo, the noise power can be accurately estimated using the actual sampled signal to calculate the diagonal loading amount.

[0026] (2) When the interference covers the entire echo, the diagonal loading can be calculated based on the theoretical noise power to avoid inaccurate estimation caused by the interference. Attached Figure Description

[0027] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0028] Figure 1 The diagram shows the radar receiving echo signals under interference conditions, where (a) indicates that the interference does not completely cover the signal, and (b) indicates that the signal is completely covered by interference.

[0029] Figure 2 This is a flowchart of the side lobe cancellation diagonal loading calculation method proposed in this invention.

[0030] Figure 3 The diagram shows the sidelobe cancellation effect after applying the present invention, where (a) is the case where the initial segment is noise, and (b) is the case where the signal is covered by interference. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Unless otherwise specified, the embodiments and features in the embodiments of this application can be arbitrarily combined with each other. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than that shown here.

[0032] The terms "first" and "second" in the specification, claims, and accompanying drawings of this application are used to distinguish different objects and not to describe a specific order. Furthermore, the term "comprising" and any variations thereof are intended to cover non-exclusive protection. For example, a process, method, system, product, or apparatus that comprises a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such processes, methods, products, or apparatus.

[0033] Because interference typically requires the acquisition, storage, and processing of radar signals before forwarding, there is usually a segment of signal at the beginning of each cycle that contains only radar receiver noise and no interference signal. Figure 1 As shown in (a); if the interference is suppressed throughout the entire period, the interference signal will exist throughout the entire cycle, making it impossible to collect the signal period with only receiver noise. Figure 1 (a) As shown. To address the problems in solving noise power under interference conditions, this invention proposes a method combining theoretical and engineering approaches for calculating sidelobe cancellation diagonal loading. Please refer to... Figure 2 Specifically, the theoretical noise power is calculated based on the system's noise temperature, and the first diagonal loading amount is calculated based on the theoretical noise power; the current noise power of the system is calculated based on the actual echo signal, and the second diagonal loading amount is determined based on the current noise power; the smaller value between the first diagonal loading amount and the second diagonal loading amount is taken as the current diagonal loading amount; the second diagonal loading amount is updated in real time based on the current noise power of the system. When the updated second diagonal loading amount is greater than the current diagonal loading amount, the first diagonal loading amount is taken as the current diagonal loading amount; otherwise, the updated second diagonal loading amount is taken as the current diagonal loading amount.

[0034] According to the technical principles of this invention, the noise power of a radar system depends on the noise bandwidth, noise temperature, and noise figure. Therefore, the noise power calculation formula is as follows:

[0035] P n,thr =kT s B N N f

[0036] Where k is the Boltzmann constant, T s For noise temperature, N f B is the noise figure. N This represents the noise bandwidth.

[0037] Considering that radar systems typically have multiple transmitted signal waveforms, and different waveform parameters may have different signal bandwidths, let's assume that the radar has M transmitted waveforms, with corresponding bandwidths of B... sig,i If i = 1, 2, ..., M, then it is used to calculate the noise power P. n,thr The noise bandwidth at that time is:

[0038]

[0039] Based on the system's noise power, the theoretical noise power corresponding to the maximum signal bandwidth is P. n,max :

[0040]

[0041] In this embodiment, the first diagonal loading amount γ thr Take the theoretical noise power P n,max A multiple of, referring to the 3σ criterion, here we take γ. thr =9P n,max The diagonal loading amount of the covariance matrix of the default sidelobe cancellation can be calculated, i.e., the first diagonal loading amount γ. thr for:

[0042]

[0043] Once the radar is activated, the second diagonal loading γ can be calculated based on partial data from each CPI echo signal, such as 0–5 µs. sig .

[0044] Assume that a radar CPI echo signal has N data points in the first 5 µs, sig(n), n = 1, 2, ..., N. Calculate the current noise power P of the system based on this signal segment. n,sig for:

[0045]

[0046] In this embodiment, the second diagonal loading amount γ is taken. sig =P n,sig .

[0047] Based on the calculation methods for the first and second diagonal loading amounts, combined with Figure 1 The process of optimizing the diagonal load can optimize the diagonal load in real time.

[0048] Specifically, after calculating the first diagonal loading amount γ thr Second diagonal loading γ sig Then, compare γ thr With γ sig If γ sig Less than or equal to γ thr Then take the current diagonal loading amount γ k =γ sig Otherwise, take γ k =γ thr As time progresses, the second diagonal loading amount γ is updated using the aforementioned calculation method for the second diagonal loading amount. sig Compare γ sig With γ k If the updated γ sig Less than or equal to γ k Then take the current diagonal loading amount γ k+1 For the updated γ sig Otherwise, take the current diagonal loading amount γ. k+1 The first diagonal recording quantity γthr This method allows for real-time updates of the diagonal loading based on the current echo signal, improving sidelobe cancellation performance.

[0049] Please refer to Figure 3 The method employed in this invention, for Figure 1 Both of these methods can achieve good sidelobe cancellation, thus eliminating interference signals.

[0050] In other embodiments of this application, an electronic device is also provided, comprising: at least one processor, and a memory communicatively connected to the at least one processor, wherein: the memory stores a computer program or instructions executable by the at least one processor, the computer program or instructions being executed by the at least one processor to enable the at least one processor to perform the method described in any of the above embodiments. It should be noted that the electronic device also has a display screen for displaying a UI (User Interface). The UI may include graphics, text, icons, videos, and any combination thereof. When the display screen is a touch display screen, the display screen also has the ability to collect touch signals on or above the surface of the display screen. The touch signals can be input to the processor as control signals for processing. In this case, the display screen can also be used to provide virtual buttons and / or a virtual keyboard, also known as soft buttons and / or a soft keyboard. In some embodiments, the display screen can be a single screen, the front panel of the electronic device; in other embodiments, the display screen can be at least two, respectively disposed on different surfaces of the electronic device or in a folded design; in still other embodiments, the display screen can be a flexible display screen, disposed on a curved surface or folded surface of the electronic device. Furthermore, the display screen can also be configured as a non-rectangular irregular shape, i.e., a non-rectangular screen. The display screen can be made of materials such as LCD (Liquid Crystal Display) and OLED (Organic Light-Emitting Diode).

[0051] In other embodiments of this application, a computer-readable storage medium is also provided, in which a computer program is stored, which, when loaded by a processor, executes any of the methods described above.

[0052] It should be noted that the processor in this application may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor may be implemented using at least one hardware form of DSP (Digital Signal Processing), FPGA (Field-Programmable Gate Array), or PLA (Programmable Logic Array). The processor may also include a main processor and a coprocessor. The main processor, also known as a CPU (Central Processing Unit), is used to process data in the wake-up state; the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, the processor may integrate a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content to be displayed on the screen. The processor may also include an AI (Artificial Intelligence) processor, which is used to handle constellation orbit data processing operations, enabling the constellation orbit data processing model to train and learn autonomously, improving efficiency and accuracy.

[0053] In other embodiments of this application, a computer-readable storage medium is also provided, which, when executed by a processor of an electronic device, enables the electronic device to perform the method described above. The computer-readable storage medium may be non-transitory. The memory may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices or flash memory devices. In some embodiments, the non-transitory computer-readable storage medium in the memory is used to store at least one instruction, which is executed by a processor to implement the sidelobe cancellation diagonal loading calculation method provided in the method embodiments of this application.

[0054] It should be noted that, within the scope of protection defined in the claims of this invention, other embodiments can be combined and / or extended or replaced in any logical manner from the above specific embodiments, such as the disclosed technical principles, disclosed technical features or implicitly disclosed technical features.

[0055] It should also be noted that the device embodiments described above are merely illustrative. The modules described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, in the accompanying drawings of the device embodiments provided by this invention, the connection relationships between modules indicate that they have communication connections, which can be specifically implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement this without any creative effort.

[0056] Through the above description of the embodiments, those skilled in the art can clearly understand that the present invention can be implemented by means of software plus necessary general-purpose hardware, and of course, it can also be implemented by special hardware including application-specific integrated circuits, special CPUs, special memory, special components, etc. Generally, any function performed by a computer program can be easily implemented by corresponding hardware, and the specific hardware structure used to implement the same function can also be diverse, such as analog circuits, digital circuits, or special-purpose circuits. However, for the present invention, software program implementation is more often the preferred implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a readable storage medium, such as a computer floppy disk, USB flash drive, portable hard disk, read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0057] For those skilled in the art, the specific meanings of the above terms in this invention can be understood according to the specific circumstances; the accompanying drawings in the embodiments are used to clearly and completely describe the technical solutions in the embodiments of this invention. Obviously, the described embodiments are some embodiments of this invention, but not all embodiments. Generally, the components of the embodiments of this invention described and shown in the accompanying drawings can be arranged and designed in various different configurations.

[0058] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for calculating the diagonal loading amount for sidelobe cancellation, characterized in that, include: The theoretical noise power is calculated by using the system's noise temperature, and the first diagonal loading amount is calculated based on the theoretical noise power. The current noise power of the system is calculated using the actual echo signal, and the second diagonal loading amount is determined based on the current noise power. Take the smaller value between the first diagonal loading amount and the second diagonal loading amount as the current diagonal loading amount; The second diagonal loading amount is updated in real time based on the current noise power of the system. When the updated second diagonal loading amount is greater than the current diagonal loading amount, the first diagonal loading amount is used as the current diagonal loading amount; otherwise, the updated second diagonal loading amount is used as the current diagonal loading amount. The theoretical noise power calculation formula is as follows: in, This represents the theoretical noise power corresponding to the maximum signal bandwidth. Let be the bandwidth corresponding to the i-th transmitted signal waveform, and k be the Boltzmann constant. For noise temperature, Noise figure; The first diagonal loading amount is based on 3 σ The criterion is taken as a multiple of the theoretical noise power; The system's current noise power calculation process includes: after the radar is started, calculating the system's current noise power based on partial data from each radar echo signal; The second method for calculating the diagonal loading amount includes: in, For the second diagonal loading amount, This represents the current noise power of the system. For the nth data point of the echo signal, is the average value of the echo signal, and N is the length of the selected data portion.

2. The method for calculating the diagonal loading amount for sidelobe cancellation according to claim 1, characterized in that, The theoretical noise power is calculated based on the system's noise bandwidth, noise temperature, and noise figure.

3. The method for calculating the diagonal loading amount of sidelobe cancellation according to claim 2, characterized in that, When the system includes multiple transmitted signal waveforms, the noise bandwidth is taken as the maximum signal bandwidth among the bandwidths corresponding to different transmitted signal waveforms.

4. An electronic device, characterized in that, It includes a memory and a processor, wherein the memory stores a computer program that can be loaded by the processor and executed corresponding to the method for calculating the diagonal loading amount of sidelobe cancellation as described in any one of claims 1 to 3.

5. A computer-readable storage medium having computer program instructions stored thereon, characterized in that, When the program instructions are executed by the processor, they are used to implement the process corresponding to the method for calculating the diagonal loading amount of sidelobe cancellation as described in any one of claims 1 to 3.

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