Target echo detection method for external radiation source radar of non-constant envelope waveform system

Abstract

The invention relates to a target echo detection method for an external radiation source radar of a non-constant envelope waveform system, and the method comprises the steps: carrying out the equal-length segmentation of a received baseband signal containing a target echo, and obtaining K segments of sub-baseband signals; performing pulse compression processing on each segment of sub-baseband signal segment by segment to obtain K pulse compression signals; performing traversal processing on the K pulse compression signals, performing unit vector extraction operation on the pulse compression signals during traversal processing, and performing fast Fourier transform on extracted unit vectors to obtain distance and Doppler two-dimensional output; and performing constant false alarm detection on the distance and Doppler two-dimensional output to obtain target distance and Doppler information. The target echo signal detection success rate can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of target echo detection, and particularly to a method for detecting target echoes for an external radiation source radar with a non-constant envelope waveform system. Background Art

[0002] External radiation source radars do not actively transmit signals. Instead, they utilize the echo signals generated when other radiation sources irradiate moving targets, and then use a target echo receiver to process the echo signals to obtain information such as the distance and speed of the moving targets. Given the advantages of wide coverage and abundant site resources of 4G and 5G wireless communication base stations, they are widely used as radiation sources for external radiation source radars. Both 4G and 5G base stations use Orthogonal Frequency Division Multiple Access (OFDMA) to transmit signals to support downlink multi-terminal communication service transmission. Multiple terminals share all downlink frequency resources. The expression of the OFDMA waveform x(t) is known as:

[0003]

[0004] where M l is the number of terminals in subframe l, Ω m is the set of downlink frequency resource numbers allocated to this terminal, and the union of all Ω m is where the set {0, 1, 2,..., P - 1} is all available downlink frequency resource numbers, and P is the maximum number of available downlink frequency resources.

[0005] Generally, for any subframe l, its M l value depends on the communication service requirements, making also different. To obtain the target echo cumulative gain, the coherent accumulation duration T cc needs to be greater than the duration of one subframe. Therefore, from the perspective of the coherent accumulation duration T cc scale, there is a power fluctuation phenomenon in the radiation source waveform, which has a non-constant envelope characteristic. The echo signal detection uses the cross ambiguity function method or the moving target detection method to detect the target echo, and separates moving targets with different speeds and static clutter from the Doppler frequency dimension. Since the radiation source waveform has a non-constant envelope characteristic, the target echo signal carrying the distance and speed information of the moving target also has a non-constant envelope characteristic. The non-constant envelope is equivalent to amplitude modulation of the target echo, resulting in distortion of its Doppler spectrum and an increase in the background noise floor, reducing the success rate of target detection. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a method for detecting target echoes for an external radiation source radar with a non-constant envelope waveform system, which can effectively improve the success rate of target echo signal detection.

[0007] The technical solution adopted by the present invention to solve its technical problems is: to provide a method for detecting target echoes for an out-of-band radiation source radar with a non-constant envelope waveform system, including the following steps:

[0008] Segment the received baseband signal containing target echoes into equal-length segments to obtain K sub-baseband signals;

[0009] Perform pulse compression processing on each sub-baseband signal segment by segment to obtain K pulse compression signals;

[0010] Perform traversal processing on the K pulse compression signals. During the traversal processing, perform unit vector extraction operation on the pulse compression signals, and perform fast Fourier transform on the extracted unit vectors to obtain two-dimensional output of range and Doppler;

[0011] Perform constant false alarm detection on the two-dimensional output of range and Doppler to obtain target range and Doppler information.

[0012] The length of the sub-baseband signal is J, where N is the length of the received baseband signal containing target echoes, denotes rounding up.

[0013] When performing the unit vector extraction operation on the pulse compression signal, divide the pulse compression signal by the modulus value of the pulse compression signal to obtain the unit vector of the pulse compression signal.

[0014] The technical solution adopted by the present invention to solve its technical problems is: to provide a device for detecting target echoes for an out-of-band radiation source radar with a non-constant envelope waveform system, including:

[0015] A segmentation module for segmenting the received baseband signal containing target echoes into equal-length segments to obtain K sub-baseband signals;

[0016] A pulse compression module for performing pulse compression processing on each sub-baseband signal segment by segment to obtain K pulse compression signals;

[0017] A traversal processing module for performing traversal processing on the K pulse compression signals. During the traversal processing, perform unit vector extraction operation on the pulse compression signals, and perform fast Fourier transform on the extracted unit vectors to obtain two-dimensional output of range and Doppler;

[0018] A constant false alarm detection module for performing constant false alarm detection on the two-dimensional output of range and Doppler to obtain target range and Doppler information.

[0019] The length of the sub-baseband signal is J, where N is the length of the received baseband signal containing target echoes, Indicates rounding up.

[0020] When the traversal processing module performs the unit vector extraction operation on the pulse compression signal, the pulse compression signal is divided by the modulus value of the pulse compression signal to obtain the unit vector of the pulse compression signal.

[0021] The technical solution adopted by the present invention to solve its technical problems is to provide an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the steps of the above-mentioned target echo detection method for non-constant envelope waveform system external radiation source radar are implemented.

[0022] The technical solution adopted by the present invention to solve its technical problems is to provide a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned target echo detection method for non-constant envelope waveform system external radiation source radar are implemented.

[0023] Beneficial effects

[0024] Due to the adoption of the above technical solution, compared with the prior art, the present invention has the following advantages and positive effects: The present invention performs segmented processing on the received baseband signal containing target echoes, then performs pulse compression on each segment, and extracts the unit vector of the pulse compression output for FFT transformation. In this way, the amplitude modulation effect of the target echo can be compensated, the power fluctuation of the target echo can be suppressed, and the detection success rate of the target echo signal can be improved. Brief description of the drawings

[0025] Figure 1 It is a flowchart of the target echo detection method according to the first embodiment of the present invention. Detailed implementation manners

[0026] The following further elaborates the present invention in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0027] The first embodiment of the present invention relates to a target echo detection method for a non-constant envelope waveform system external radiation source radar, as Figure 1 shown, including the following steps:

[0028] Step 1: Segment the received baseband signal containing the target echo into equal-length segments to obtain K sub-baseband signals. In this step, the received baseband signal containing the target echo is x[n], where n = 0, 1, 2, ..., N - 1, and N is the length of the received baseband signal containing the target echo. When using equal-length segmentation, the baseband signal x[n] containing the target echo can be divided into K sub-baseband signals, where J is the length of the sub-baseband signal, denotes rounding up. Among them, the k-th sub-baseband signal x k [n′], where n′ = kJ + j, k = 0, 1, ..., K - 1, j = 0, 1, ..., J - 1.

[0029] Step 2: Perform pulse compression processing on each sub-baseband signal segment by segment to obtain K pulse compression signals. Assume that pulse compression processing is performed on the k-th sub-baseband signal x k [n′], and the k-th pulse compression signal obtained is y k [m′].

[0030] Step 3: Perform a traversal process on the K pulse compression signals. During the traversal process, perform a unit vector extraction operation on the pulse compression signals, and perform a fast Fourier transform on the extracted unit vectors to obtain a two-dimensional output of range and Doppler.

[0031] In this step, when performing the unit vector extraction operation on the pulse compression signal, divide the pulse compression signal by the modulus value of the pulse compression signal to obtain the unit vector of the pulse compression signal, that is where z k [m′] is the unit vector of the k-th pulse compression signal.

[0032] Step 4: Perform a constant false alarm rate detection on the two-dimensional output of range and Doppler to obtain the target range and Doppler information.

[0033] It is not difficult to find that the present invention performs segmentation processing on the received baseband signal containing the target echo, then performs pulse compression on each segment, and extracts the unit vector of the pulse compression output for FFT transformation. By this method, the amplitude modulation effect of the target echo can be compensated, the power fluctuation of the target echo can be suppressed, and the detection success rate of the target echo signal can be improved.

[0034] The second embodiment of the present invention relates to a target echo detection device for an out-of-band radiation source radar with a non-constant envelope waveform system, including:

[0035] A segmentation module, configured to segment the received baseband signal containing the target echo into equal-length segments to obtain K sub-baseband signals;

[0036] A pulse compression module, which is used to perform pulse compression processing on each sub-baseband signal segment by segment to obtain K pulse compression signals;

[0037] A traversal processing module, which is used to perform traversal processing on the K pulse compression signals. During the traversal processing, a unit vector extraction operation is performed on the pulse compression signals, and a fast Fourier transform is performed on the extracted unit vectors to obtain a two-dimensional output of range and Doppler;

[0038] A constant false alarm detection module, which is used to perform constant false alarm detection on the two-dimensional output of range and Doppler to obtain target range and Doppler information.

[0039] The length of the sub-baseband signal is J, where N is the length of the baseband signal containing the target echo received, denotes rounding up.

[0040] When the traversal processing module performs the unit vector extraction operation on the pulse compression signal, the pulse compression signal is divided by the modulus value of the pulse compression signal to obtain the unit vector of the pulse compression signal.

[0041] The third embodiment of the present invention relates to an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the steps of the target echo detection method for non-constant envelope waveform system out-of-band radiation source radar in the first embodiment are implemented.

[0042] The fourth embodiment of the present invention relates to a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the target echo detection method for non-constant envelope waveform system out-of-band radiation source radar in the first embodiment are implemented.

[0043] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) containing computer-usable program code.

[0044] This application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, as well as the combination of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to the processors of general-purpose computers, special-purpose computers, embedded processors, or other programmable data processing devices to generate a machine, such that the instructions executed by the processors of the computer or other programmable data processing devices generate means for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0045] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including an instruction method that implements the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0046] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0047] As described above, the above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims described.

Claims

1. A method for target echo detection of an out-of-band radiation source radar with a non-constant envelope waveform system, characterized in that, It includes the following steps: Perform equal-length segmentation on the received baseband signal containing the target echo to obtain K sub-baseband signals; Perform pulse compression processing on each sub-baseband signal segment by segment to obtain K pulse compression signals; Perform traversal processing on the K pulse compression signals. During the traversal processing, perform unit vector extraction operation on the pulse compression signal and perform fast Fourier transform on the extracted unit vector to obtain range and Doppler two-dimensional output; Perform constant false alarm rate detection on the range and Doppler two-dimensional output to obtain target range and Doppler information.

2. The method for target echo detection for an out-of-band radiation source radar with a non-constant envelope waveform system according to claim 1, characterized in that The length of the sub-baseband signal is J, where N is the length of the received baseband signal containing the target echo, represents rounding up.

3. The method for detecting target echoes of an out-of-band radiation source radar using a non-constant envelope waveform system according to claim 1, characterized in that When performing the unit vector extraction operation on the pulse compression signal, divide the pulse compression signal by the modulus value of the pulse compression signal to obtain the unit vector of the pulse compression signal.

4. A target echo detection device for a non-constant envelope waveform system out-of-band radiation source radar, characterized in that, It includes: A segmentation module for performing equal-length segmentation on the received baseband signal containing the target echo to obtain K sub-baseband signals; A pulse compression module for performing pulse compression processing on each sub-baseband signal segment by segment to obtain K pulse compression signals; A traversal processing module for performing traversal processing on the K pulse compression signals. During the traversal processing, perform unit vector extraction operation on the pulse compression signal and perform fast Fourier transform on the extracted unit vector to obtain range and Doppler two-dimensional output; A constant false alarm rate detection module for performing constant false alarm rate detection on the range and Doppler two-dimensional output to obtain target range and Doppler information.

5. The target echo detection device for the non-constant envelope waveform-based external radiation source radar according to claim 4, wherein The length of the sub-baseband signal is J, where N is the length of the received baseband signal containing the target echo, denotes rounding up.

6. The target echo detection device for the non-constant envelope waveform-based external radiation source radar according to claim 4, characterized in that, When the traversal processing module performs the unit vector extraction operation on the pulse compression signal, divide the pulse compression signal by the modulus value of the pulse compression signal to obtain the unit vector of the pulse compression signal.

7. An electronic device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein When the processor executes the computer program, it implements the steps of the target echo detection method for non-constant envelope waveform system out-of-band radiation source radar as described in any one of claims 1-3.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the target echo detection method for non-constant envelope waveform system out-of-band radiation source radar as described in any one of claims 1-3.

Images