Wind profile radar co-frequency interference suppression method and device, medium and program

Abstract

This invention provides a method, apparatus, medium, and program for suppressing co-channel interference in wind profiler radar. First, based on the constant-mode characteristic of co-channel interference, the co-channel interference in the received signal of the echo channel is converted into DC interference. This DC interference is then eliminated to suppress the co-channel interference, yielding the remaining received signal in the echo channel. Next, based again on the constant-mode characteristic of co-channel interference, the influence of co-channel interference on the remaining received signal in the echo channel is eliminated, resulting in the target echo signal after co-channel interference suppression. Compared to existing technologies that cannot suppress strong co-channel interference, this invention effectively suppresses strong co-channel interference in the target echo channel based on the constant-mode characteristic of modulated co-channel interference. The suppression process only involves two multiplication operations between the received signal from the co-channel interference channel and the received signal from the echo channel, and one subtraction operation to eliminate DC interference; therefore, the entire calculation process is simple and efficient.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of radar interference suppression, and particularly relates to a wind profile radar co-frequency interference suppression method, device, medium and program. BACKGROUND

[0002] The wind profile radar can continuously and real-timely measure the distribution of the air wind field, and it takes the turbulence existing in the atmosphere as a target, uses the scattering effect of the atmospheric turbulence on the radar electromagnetic wave to detect the air wind speed and direction. Compared with other detection methods, the wind profile radar has the advantages of high time / space resolution, high cost-effective ratio for long-term use, high reliability and the like. The wind profile radar is mainly used in many aspects such as meteorological departments at all levels, aviation flight support, air quality forecast and urban environmental meteorological service.

[0003] In some large equipment, due to the strict spectrum management restriction, the wind profile radar and the satellite communication system work in the same frequency band, so there is mutual interference problem, and because the distance between the two is very close, the communication system leaks to the direct wave of the radar (i.e. co-frequency interference) is several decibels or even more than 100 dB stronger than the target echo signal received by the radar, which seriously affects the wind measurement performance of the radar, therefore, how to effectively suppress the strong co-frequency interference becomes an important problem faced by the wind profile radar. The document (Han Xu, Dan Yu Zhou, Ren Bo Sen, etc. An improved weather radar co-frequency asynchronous interference suppression method [J]. Journal of Chengdu University of Information Technology, 2026, 41(01): 63-70.) analyzes the co-frequency interference phenomenon of the weather radar, studies a two-dimensional space-time filtering algorithm for co-frequency interference identification and suppression, and achieves certain effect, but the algorithm requires that the strength of the co-frequency interference is not very large, and the suppression effect on the strong co-frequency interference is limited. SUMMARY

[0004] In view of the deficiencies in the prior art, the application provides a wind profile radar co-frequency interference suppression method, device, medium and program to solve the problem of strong co-frequency interference mixed in the target echo channel of the wind profile radar.

[0005] The application achieves the above technical object through the following technical means.

[0006] A wind profile radar co-frequency interference suppression method, characterized in that:

[0007] Step 1, based on the constant modulus characteristic of the co-frequency interference, the co-frequency interference in the echo channel received signal is changed into direct current interference, the co-frequency interference is suppressed by eliminating the direct current interference, and the remaining received signal of the echo channel is obtained;

[0008] Step 2, based on the constant modulus characteristic of the co-channel interference, eliminate the influence of the co-channel interference on the echo channel residual received signal, and obtain the target echo signal after co-channel interference suppression.

[0009] Further, for the target echo signal received by the wind profile radar and the co-channel interference signal , step 1 includes:

[0010] Step 1.1, take the conjugate of and multiply it by to obtain the signal ;

[0011] Step 1.2, take the mean of the signal to obtain the direct current interference;

[0012] Step 1.3, remove the direct current interference from the signal to obtain the residual received signal .

[0013] Step 2 is to multiply the signal by to obtain the target echo signal after co-channel interference suppression .

[0014] Further, perform fast Fourier transform on the signal to obtain the Doppler spectrum of the wind profile target.

[0015] Further, before fast Fourier transform, first perform pulse compression processing on the signal .

[0016] Further, based on the Doppler spectrum, extract meteorological information, including: echo power of wind layer, average wind speed, wind speed standard deviation.

[0017] The received target echo signal is represented as:

[0018]

[0019] The received co-channel interference signal is represented as:

[0020]

[0021] The target echo signal after co-channel interference suppression is represented as:

[0022]

[0023] In the formula, is the actual target echo signal, and are time delay and Doppler frequency of the target echo signal respectively, is imaginary unit, is real co-frequency interference signal, is other interference signal, is time variable, is amplitude of the co-frequency interference signal.

[0024] A computer device comprising a memory and a processor;

[0025] The memory is used to store a computer program;

[0026] The processor is used to execute the computer program and realize the above-mentioned wind profile radar co-frequency interference suppression method when executing the computer program.

[0027] A computer readable storage medium storing a computer program, the computer program being executed by a processor to make the processor execute the above-mentioned wind profile radar co-frequency interference suppression method.

[0028] A computer program product comprising a computer program, the computer program being executed by a processor to realize the above-mentioned wind profile radar co-frequency interference suppression method.

[0029] The beneficial effects of the present application are:

[0030] (1) The present application provides a wind profile radar co-frequency interference suppression method, device, medium and program, which can effectively suppress strong co-frequency interference in the target echo channel based on the constant modulus characteristic of the co-frequency interference, compared with the prior art which cannot suppress strong co-frequency interference. Theoretical analysis and simulation examples below verify its effect.

[0031] (2) The co-frequency interference suppression process of the present application only performs multiplication operation of the co-frequency interference channel received signal and the echo channel received signal twice, and subtraction operation of eliminating direct current interference once, so that the whole operation process is simple and efficient. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a flowchart of the present application;

[0033] Figure 2 is the real Doppler spectrum of the echo channel received signal not affected by co-frequency interference in the simulation of the present application;

[0034] Figure 3 is the echo channel received signal affected by co-frequency interference in the simulation of the present application;

[0035] Figure 4This is the Doppler spectrum of the echo channel received signal affected by co-channel interference, as simulated in this invention.

[0036] Figure 5 This is the echo channel received signal after suppressing co-channel interference, as simulated in this invention.

[0037] Figure 6 The Doppler frequency of the echo channel received signal after suppressing co-channel interference in the simulation of this invention. Detailed Implementation

[0038] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

[0039] I. Methods

[0040] According to radar design requirements, the receiving channel of a wind profiler radar includes a target echo channel and a co-channel interference channel. The former is used to receive target echo signals, while the latter is specifically used to receive direct-wave co-channel interference from satellite communication systems. It is known that this co-channel interference has constant mode characteristics. Based on this, the present invention provides a wind profiler radar co-channel interference suppression method based on constant mode characteristics, which can effectively suppress strong co-channel interference mixed in the target echo channel, facilitating subsequent processing of the target echo signal to extract the required wind profiler information.

[0041] like Figure 1 As shown, the wind profiler radar co-channel interference suppression method of the present invention includes the following:

[0042] 1. Establish a mathematical model for the wind profiler radar receiving signal to obtain the received signal of the target echo channel and the received signal of the co-frequency interference channel.

[0043] 1.1 The echo channel of the wind profiler radar is used to receive target echo signals. It will also receive strong co-channel interference and other interference signals. Therefore, the received signal of the echo channel... Represented as:

[0044]

[0045] In the formula, The actual target echo signal, and These represent the time delay and Doppler frequency of the target echo signal, respectively. The imaginary unit, This is an actual co-channel interference signal. Other interference signals, It is a time variable.

[0046] 1.2, the co-channel jamming channel of the wind profiler radar is specifically designed to receive co-channel jamming. It provides a clean co-channel jamming signal, and the co-channel jamming signal received by this channel is... Represented as:

[0047]

[0048] In the formula, This represents the amplitude of the co-channel interference signal.

[0049] 2. By utilizing the constant-mode nature of co-channel interference, the co-channel interference in the received signal of the echo channel is transformed into DC interference. By eliminating this DC interference, the co-channel interference is suppressed, and the remaining received signal of the echo channel is obtained.

[0050] 2.1 Assume co-channel interference entering the wind profiler radar. It is a random phase-modulated signal with constant mode characteristics, and its amplitude satisfies the condition. ,Will Take conjugate and AND Multiplying, makes If the co-channel interference is converted into DC interference, then the received signal in the echo channel after multiplication will be different. for:

[0051]

[0052] In the formula, Indicates DC interference, superscript Indicates taking the conjugate;

[0053] 2.2 Taking the average of the above formula, we get:

[0054]

[0055] In the formula, This indicates taking the average value;

[0056] 2.3, from Subtract To eliminate DC interference This suppresses co-channel interference, and the remaining received signal in the echo channel is:

[0057]

[0058] 3. By utilizing the constant-mode property of co-channel interference again, the influence of co-channel interference on the remaining received signal of the echo channel is eliminated, and the required target echo signal is obtained. Finally, the target echo signal is processed to achieve target detection and meteorological parameter estimation.

[0059] 3.1, will and Multiplication, utilizing constant model properties eliminate Co-channel interference To mitigate the impact of [the virus], the desired target echo signal is obtained:

[0060]

[0061] 3.2 The target echo signal is processed by pulse compression (if necessary) and Fast Fourier Transform (FFT) to obtain the Doppler spectrum of the wind profile target. Based on this spectrum, wind profile target detection can be achieved, and important meteorological parameters such as target power, average wind speed, and wind speed standard deviation can be extracted.

[0062] II. Test

[0063] The co-channel interference suppression method of the wind profiler radar of the present invention is simulated, and the performance of co-channel interference suppression is verified through simulation examples.

[0064] Assume the wind profiler radar operates at a frequency of 10 GHz, transmits a signal pulse width of 0.8 μs, has a pulse repetition period of 20 μs, accumulates 512 coherent pulses, has a wind layer height of 1200 m, an average wind speed of 10 m / s, and a standard deviation of 3 m / s.

[0065] Assume that the radar co-channel interference uses a randomly phase-modulated signal with constant mode characteristics; the radar receiver has two receiving channels, namely the echo channel and the co-channel interference channel. The echo channel receives a signal consisting of a target echo signal, a strong co-channel interference, and background noise superimposed on each other, with a signal-to-interference ratio of -25.7dB and a signal-to-noise ratio of -3.3dB; the co-channel interference channel receives a signal containing only one co-channel interference.

[0066] Figure 2 The true Doppler spectrum of the echo channel received signal, unaffected by co-channel interference, is shown. It is generated based on the previous simulation parameters, and the spectral peaks between 0 and 20 m / s contain meteorological information such as the echo power, average wind speed, and wind speed standard deviation of the wind layer.

[0067] Figure 3 The image shows the received signal of the echo channel affected by co-channel interference. The target echo signal is very weak, while the co-channel interference is very strong. Therefore, the target echo signal is submerged in the co-channel interference, and the main component of the received signal is the co-channel interference.

[0068] Figure 4 It shows Figure 3 The Doppler spectrum of the received signal shows that the peaks of the target echo signal between 0 and 20 m / s are completely obscured and cannot be detected.

[0069] Figure 5 The present invention illustrates the processing method for... Figure 3The result of processing the signal in the echo channel is the echo channel received signal after suppressing co-channel interference, which shows that co-channel interference is effectively suppressed.

[0070] Figure 6 It shows Figure 5 The spectrum of the processed signal, i.e., the Doppler spectrum of the echo channel received signal after suppressing co-channel interference, shows that the spectral peaks between 0 and 20 m / s reappear, with shapes similar to... Figure 4 They are basically the same, so meteorological information such as echo power, average wind speed and wind speed standard deviation of the wind layer can be extracted from them.

[0071] In summary, a comparison of the processing results before and after co-channel interference suppression of the received signal in the echo channel shows that before co-channel interference suppression, the target echo signal is submerged in co-channel interference, making target detection and meteorological parameter extraction impossible. However, after the co-channel interference is suppressed, the spectral peaks of the target echo reappear, which can be used to extract meteorological information, thus achieving the desired purpose. Therefore, the co-channel interference suppression method of the present invention has good effect.

[0072] III. Devices, storage media, and software products

[0073] 1. Based on the same inventive concept as the above-mentioned wind profiler radar co-frequency interference suppression method, this application also provides an electronic device, which includes a processor and a memory, wherein computer-readable code is stored in the memory, and when the computer-readable code is executed by the processor, the wind profiler radar co-frequency interference suppression method of the present invention is implemented.

[0074] The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium can store the operating system and computer-readable code. The computer-readable code includes program instructions that, when executed, cause the processor to perform a method for suppressing co-channel interference with wind profiler radar. The processor provides computational and control capabilities to support the operation of the entire electronic device. The memory provides an environment for the execution of the computer-readable code in the non-volatile storage medium, which, when executed by the processor, causes the processor to perform a method for suppressing co-channel interference with wind profiler radar.

[0075] It should be understood that a processor can be a central processing unit, other general-purpose processors, digital signal processors, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) or other programmable logic devices, transistor logic devices, discrete hardware components, etc. Among them, a general-purpose processor can be a microprocessor or any conventional processor.

[0076] 2. This application also provides a readable storage medium, which may be an internal storage unit of the electronic device described in the foregoing embodiments, such as the hard disk or memory of the computer device. The readable storage medium may also be an external storage device of the electronic device, such as a plug-in hard disk, smart memory card, or secure digital card equipped on the electronic device.

[0077] 3. This application also provides a computer program product, including a computer program or instructions, which, when executed by a processor, implements the co-channel interference suppression method for wind profiler radar of the present invention.

[0078] This invention is not limited to the above-described embodiments. Any obvious improvements, substitutions, or modifications that can be made by those skilled in the art without departing from the essence of this invention are within the scope of protection of this invention.

Claims

1. A method for suppressing co-channel interference in wind profiler radar, characterized in that: Step 1: Based on the constant mode characteristic of co-channel interference, the co-channel interference in the received signal of the echo channel is converted into DC interference. By eliminating this DC interference, the co-channel interference is suppressed, and the remaining received signal of the echo channel is obtained. Step 2: Based on the constant mode characteristic of co-channel interference, eliminate the influence of co-channel interference on the remaining received signal of the echo channel to obtain the target echo signal after co-channel interference suppression.

2. The wind profiler radar co-channel interference suppression method according to claim 1, characterized in that: Target echo signals received by wind profiler radar and co-channel interference signals Step 1 includes: Step 1.1, will Take conjugate and AND Multiply to obtain the signal ; Step 1.2, for the signal The average value is taken to obtain the DC interference; Step 1.3, remove DC interference from the signal Remove from the middle to obtain the remaining received signal. .

3. The wind profiler radar co-frequency interference suppression method according to claim 2, characterized in that: Step 2 is: to transfer the signal and Multiplying them together yields the target echo signal after suppressing co-frequency interference. .

4. The wind profiler radar co-channel interference suppression method according to claim 3, characterized in that: For signals Perform a fast Fourier transform to obtain the Doppler spectrum of the wind profile target.

5. The wind profiler radar co-channel interference suppression method according to claim 4, characterized in that: Before performing the Fast Fourier Transform, first analyze the signal. Perform pulse compression processing.

6. The wind profiler radar co-channel interference suppression method according to claim 4, characterized in that: Based on the Doppler spectrum, meteorological information is extracted, including: echo power of the wind layer, average wind speed, and wind speed standard deviation.

7. The wind profiler radar co-channel interference suppression method according to claim 3, characterized in that: The received target echo signal Represented as: Received co-channel interference signal Represented as: Target echo signal after co-channel interference suppression Represented as: In the formula, The actual target echo signal, and These represent the time delay and Doppler frequency of the target echo signal, respectively. The imaginary unit, This is an actual co-channel interference signal. Other interference signals, For time variables, This represents the amplitude of the co-channel interference signal.

8. A computer device, characterized in that: Including memory and processor; The memory is used to store computer programs; The processor is used to execute the computer program and, in executing the computer program, implement the wind profiler radar co-channel interference suppression method as described in any one of claims 1 to 7.

9. A computer-readable storage medium, characterized in that: The system contains a computer program that, when executed by a processor, causes the processor to perform the wind profiler radar co-channel interference suppression method as described in any one of claims 1 to 7.

10. A computer program product, characterized in that: The method includes a computer program that, when executed by a processor, implements the wind profiler radar co-channel interference suppression method as described in any one of claims 1 to 7.

Images