阅读说明：本技术 可实现大距离范围探测的宽带信号压缩感知装置及方法 (Broadband signal compression sensing device and method capable of realizing large-distance range detection ) 是由 郑小平 徐熠蓉 李尚远 薛晓晓 于 2021-07-27 设计创作，主要内容包括：本发明公开了一种可实现大距离范围探测的宽带信号压缩感知装置及方法,可应用于雷达探测。将待接收回波通过电光调制加载在单频光载波上,之后送到光学三元混频模块中,同时实现分数阶傅里叶域自适应本振与回波信号的混频以及随机码对于混频后中音信号的随机调制,再送到电模数转换器中进行采集,通过数字信号处理做压缩感知恢复、并进一步地恢复得到完整的波形。通过构建分数阶傅里叶域自适应本振,本发明对一定距离窗口内回波进行混频,实现该距离窗口内分辨率一致的探测,并降低了对于接收端带宽的要求。(The invention discloses a broadband signal compression sensing device and method capable of realizing large-distance range detection, which can be applied to radar detection. The method comprises the steps of loading echoes to be received on a single-frequency optical carrier through electro-optical modulation, then sending the echoes to an optical ternary frequency mixing module, simultaneously realizing frequency mixing of a fractional order Fourier domain self-adaptive local oscillator and echo signals and random modulation of random codes on the mixed middle-tone signals, then sending the mixed middle-tone signals to an electric analog-to-digital converter for collection, and performing compressed sensing recovery and further recovery through digital signal processing to obtain a complete waveform. By constructing the fractional Fourier domain self-adaptive local oscillator, the invention mixes the frequency of the echo in a certain distance window, realizes the detection with consistent resolution in the distance window, and reduces the requirement on the bandwidth of a receiving end.)

1. A compressed sensing device of broadband signals capable of realizing large-distance range detection is characterized by comprising:

a single frequency light source for emitting single frequency light;

the first intensity modulator is used for loading a signal to be measured on the single-frequency light to generate an optical modulation signal;

the input end of the first optical coupler is connected with the output end of the first intensity modulator, and the output end of the first optical coupler is divided into an I path output and a Q path output and is used for dividing the optical modulation signal into an I path and a Q path;

the input end of the first optical frequency mixing module is connected with the I-path output of the first optical coupler, and the input end of the second optical frequency mixing module is connected with the Q-path output of the first optical coupler, so that the optical modulation signal is used for sampling a fractional Fourier domain self-adaptive local oscillator and a random code, and two paths of optical output signals are obtained;

the input end of the first processing module is connected with the output end of the first optical frequency mixing module, the input end of the second processing module is connected with the output end of the second optical frequency mixing module, and the first processing module and the second processing module are respectively used for converting the optical output signals into electrical output signals and amplifying and filtering the electrical output signals to obtain two paths of results;

the input end of the analog-to-digital converter is respectively connected with the output ends of the first processing module and the second processing module and is used for collecting the two paths of results;

and the imaging module is used for processing the two collected paths of results to obtain an imaging result of the signal to be detected.

2. The apparatus according to claim 1, wherein the imaging module is specifically configured to perform sparse recovery on the two results, further obtain an echo waveform, and perform pulse compression by using the echo waveform and an ideal chirp wave to obtain an imaging result of the signal to be measured.

3. The apparatus of claim 1, wherein the first processing module and the second processing module are identical in structure and respectively comprise a photodetector, a microwave amplifier and a low-pass filter;

the input end of the photoelectric detector is connected with the output end of the optical frequency mixing module, the output end of the photoelectric detector is connected with the input end of the microwave amplifier, the output end of the microwave amplifier is connected with the input end of the low-pass filter, and the output end of the low-pass filter is the output end of the processing module.

4. The apparatus of claim 1, wherein the bandwidth of the mid-tone signal after the signal under test and the fractional order fourier domain adaptive local oscillator in the optical frequency mixing module are mixed is less than one half of the random code rate.

5. The apparatus according to any of claims 1-4, wherein the modulation rate of the intensity modulator is greater than the maximum frequency of the signal under test.

6. A method for sensing broadband signal compression capable of realizing large-distance range detection, which is used for the device for sensing broadband signal compression capable of realizing large-distance range detection as claimed in claims 1-5, and is characterized by comprising the following steps:

loading a signal to be measured on single-frequency light to generate an optical modulation signal;

dividing the optical modulation signal into two paths, and sampling a fractional order Fourier domain self-adaptive local oscillator and a random code to obtain two paths of optical output signals;

converting the optical output signal into an electrical output signal, and amplifying and filtering the electrical output signal to obtain two paths of results;

and acquiring and processing the two paths of results to obtain an imaging result of the signal to be detected.

Technical Field

The invention relates to the technical field of radar target detection, in particular to a broadband signal compression sensing device and method capable of realizing large-distance range detection, and the device and method can be applied to radar detection.

Background

The radar transmits electromagnetic waves and receives and processes reflected echoes of a target to obtain a two-dimensional image, and the radar is an important means for detecting and identifying a non-cooperative target. Linear Frequency Modulated (LFM) signals have a large time bandwidth product, and can meet the requirements of radar detection with a large range and high resolution, so that the signals have wide application in radar detection. The receiving mode of the chirp wave commonly adopted in the radar detection at present is de-skew (de-chirp), that is, the receiver adopts the broadband chirp wave with the same chirp rate to mix the echo signal, and converts the broadband echo signal into a narrowband mediant signal, thereby reducing the requirement on the bandwidth of the analog-to-digital converter at the receiving end. However, the resolution of the receiving method of deskewing is inversely proportional to the overlapping bandwidth between the local oscillation chirp waves and the echoes, which limits the capability of radar in detecting scenes in a large distance range, and therefore the solution of the problem is particularly important.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art.

Therefore, an object of the present invention is to provide a wideband signal compressed sensing apparatus capable of achieving large-distance range detection, which can be applied to radar detection.

Another objective of the present invention is to provide a method for compressed sensing of broadband signals, which can implement large-distance range detection.

In order to achieve the above object, an embodiment of the present invention provides a wideband signal compressed sensing apparatus capable of achieving large-range detection, including:

a single frequency light source for emitting single frequency light;

the first intensity modulator is used for loading a signal to be measured on the single-frequency light to generate an optical modulation signal;

the input end of the first optical coupler is connected with the output end of the first intensity modulator, and the output end of the first optical coupler is divided into an I path output and a Q path output and is used for dividing the optical modulation signal into an I path and a Q path;

the input end of the first optical frequency mixing module is connected with the I-path output of the first optical coupler, and the input end of the second optical frequency mixing module is connected with the Q-path output of the first optical coupler, so that the optical modulation signal can sample fractional Fourier domain self-adaptive local oscillators and random codes to obtain two paths of optical output signals;

the input end of the first processing module is connected with the output end of the first optical frequency mixing module, the input end of the second processing module is connected with the output end of the second optical frequency mixing module, and the first processing module and the second processing module are respectively used for converting the optical output signals into electrical output signals and amplifying and filtering the electrical output signals to obtain two paths of results;

the input end of the analog-to-digital converter is respectively connected with the output ends of the first processing module and the second processing module and is used for collecting the two paths of results;

and the imaging module is used for processing the two collected paths of results to obtain an imaging result of the signal to be detected.

In order to achieve the above object, another embodiment of the present invention provides a method for compressed sensing of a broadband signal, which can implement large-range detection, including the following steps:

loading a signal to be measured on single-frequency light to generate an optical modulation signal;

dividing the optical modulation signal into two paths, and sampling a fractional order Fourier domain self-adaptive local oscillator and a random code to obtain two paths of optical output signals;

converting the optical output signal into an electrical output signal, and amplifying and filtering the electrical output signal to obtain two paths of results;

and acquiring and processing the two paths of results to obtain an imaging result of the signal to be detected.

The broadband signal compression sensing device and the method for realizing the large-distance range detection have the following beneficial effects that: by constructing the fractional Fourier domain self-adaptive local oscillator, the frequency mixing can be carried out on the echo in a certain distance window, so that the resolution in the distance window is ensured to be consistent. In addition, the device has low requirement on the bandwidth of the electric analog-digital converter, and can realize the detection of consistent resolution in a large distance range only by the bandwidth of hundreds of MHz magnitude.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The foregoing and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a block diagram of a wideband signal compressive sensing apparatus capable of detecting a large distance range according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a wideband signal compressive sensing apparatus capable of detecting a large distance range according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of the detection results of two targets at 196.1m and 7446.1m, which are 3cm apart, according to one embodiment of the present invention;

FIG. 4 is a schematic diagram of the detection results of two targets at 196.1m and 7446.1m, which are 2.5cm apart, according to one embodiment of the present invention;

FIG. 5 is a graph of experimental results of imaging a four-ball turret at 156.3m, 7406.3m, according to one embodiment of the present invention;

FIG. 6 is a flowchart of a method for compressed sensing of broadband signals that can achieve detection in a large range according to an embodiment of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

The following describes a wideband signal compressed sensing apparatus and method capable of achieving large-range detection according to an embodiment of the present invention with reference to the accompanying drawings.

First, a broadband signal compressed sensing device capable of detecting a large distance range according to an embodiment of the present invention will be described with reference to the accompanying drawings.

Fig. 1 is a block diagram of a wideband signal compressive sensing apparatus capable of detecting a large distance range according to an embodiment of the present invention.

As shown in FIG. 1, the apparatus 10 for sensing a wide-band signal with compressed signal capable of achieving detection in a large distance range includes: a single frequency light source 101, a first intensity modulator 102, a first optical coupler 103, a first optical mixing module 104, a second optical mixing module 105, a first processing module 106, a second processing module 107, an analog-to-digital converter 108, and an imaging module 109.

Specifically, a single-frequency light source 101 for emitting single-frequency light. The first intensity modulator 102 is configured to load a signal to be measured onto a single-frequency light to generate an optical modulation signal. And the input end of the first optical coupler 103 is connected with the output end of the first intensity modulator 102, and the output end of the first optical coupler is divided into an I path output and a Q path output and is used for dividing the optical modulation signal into an I path and a Q path. The optical modulation device comprises a first optical frequency mixing module 104 and a second optical frequency mixing module 105, wherein the input end of the first optical frequency mixing module is connected with the I-path output of a first optical coupler, and the input end of the second optical frequency mixing module is connected with the Q-path output of the first optical coupler, and is used for sampling fractional order Fourier domain self-adaptive local oscillators and random codes through optical modulation signals and obtaining two paths of optical output signals. The input end of the first processing module is connected with the output end of the first optical frequency mixing module, and the input end of the second processing module is connected with the output end of the second optical frequency mixing module, and the first processing module 106 and the second processing module 107 are respectively used for converting optical output signals into electrical output signals and amplifying and filtering the electrical output signals to obtain two paths of results. And the input end of the analog-to-digital converter 108 is respectively connected with the output ends of the first processing module and the second processing module and is used for collecting two paths of results. And the imaging module 109 is used for processing the two collected paths of results to obtain an imaging result of the signal to be detected.

The structure of the broadband signal compressed sensing device capable of achieving large-distance range detection is described in detail with reference to fig. 2.

In the embodiment of the present invention, the first optical mixing module 104 and the second optical mixing module 105 may be, but not limited to, a dual-parallel modulator, and it should be noted that other devices that can implement the functions of the optical mixing module of the present invention may also be used in the embodiment of the present invention, and are not limited in particular.

In the embodiment of the invention, the first processing module and the second processing module have the same structure and respectively comprise a photoelectric detector, a microwave amplifier and a low-pass filter; the input end of the photoelectric detector is connected with the output end of the optical frequency mixing module, the output end of the photoelectric detector is connected with the input end of the microwave amplifier, the output end of the microwave amplifier is connected with the input end of the low-pass filter, and the output end of the low-pass filter is the output end of the processing module.

In the embodiment of the invention, the bandwidth of the mid-tone signal after the signal to be tested and the fractional Fourier domain self-adaptive local oscillator in the optical frequency mixing module are mixed is less than one half of the code rate of the random code.

It should be noted that the modulation rate of the intensity modulator is greater than the maximum frequency of the echo signal to be measured. The modulation rate of the optical frequency mixing module is greater than the maximum frequency of the fractional order self-adaptive local oscillation signal and the maximum frequency of the random code. The code rate of the random code is larger than the Nyquist rate of the middle voice signal after the fractional order self-adaptive local oscillation signal and the echo signal are mixed.

The working flow of the broadband signal compression sensing device capable of realizing the detection of the large distance range is described in conjunction with fig. 2 and a specific embodiment.

1) To receive echo signal x₀(t)＝exp{j[2πf₀(t-τ)+πk(t-τ)²]The light is loaded onto the single frequency light via an intensity modulator. Wherein f is₀And k is the initial frequency and chirp rate of the echo signal to be received, respectively, and its bandwidth is B₀The signal duration in the period being T_sigZero duty cycle of the signal is T_z。

2) Self-adaptive local oscillator by constructing fractional Fourier domainEnsuring that the self-adaptive local oscillator can perform echo x in a certain distance window₀(t) mixing is performed so as to secure the distanceThe resolution within the window is consistent.

3) And (2) respectively sending the output optical signals in the step 1) to I, Q optical frequency mixing modules, so as to sample I, Q fractional order Fourier domain self-adaptive local oscillators and random codes.

4) And 3) transmitting the optical signal obtained in the step 3) to a photoelectric detector, a microwave amplifier and a low-pass filter, and transmitting the optical signal as a final result to an electric analog-digital converter for collection.

5) Performing sparse recovery according to the I, Q paths of compressed sensing results acquired in the step 4), and further obtaining an echo waveform x_rec(t)。

6) Complete echo x obtained by recovery_recAnd (t) performing pulse compression with the ideal linear frequency modulation wave to obtain the results of distance measurement and imaging.

In an embodiment of the invention, a large-distance range ranging and imaging experiment is performed by using the broadband signal compression sensing device capable of realizing large-distance range detection. In this experiment, the transmission waveform was set to a bandwidth of B₀The cycle of the linear frequency modulation wave is 100us, the duty ratio is 50%, and the fractional Fourier domain self-adaptive local oscillator is designed to ensure that the bandwidth of the middle-tone signal after the frequency mixing of the echo and the self-adaptive local oscillator is B₀2 so that the system can achieve a large range detection of 7.5 km. In the experiment, an arbitrary waveform generator is used for generating echoes to be measured, and the echoes are used for simulating echoes with two close-range targets at 196.1m and 7446.1m respectively. Two paths of output of the system are collected through an electric analog-digital converter, a complete waveform is obtained through digital signal processing and recovery, and pulse pressure is carried out on the complete waveform and an ideal linear frequency modulation wave, so that a distance measurement result is obtained. When the distance between the two targets at 196.1m and 7446.1m is set to be 3cm, the ranging result is shown in FIG. 3; when the distance between the two targets at 196.1m and 7446.1m is set to be 2.5cm, the ranging result is shown in FIG. 4. Further, four-ball turrets each having a radius of 30cm at 156.3m, 7406.3m were simulated using an arbitrary waveform generator, and the imaging results obtained are shown in fig. 5.

The broadband signal compression sensing device capable of realizing large-distance range detection provided by the embodiment of the invention can be applied to radar detection. The method comprises the steps of loading echoes to be received on a single-frequency optical carrier through electro-optical modulation, then sending the echoes to an optical ternary frequency mixing module, simultaneously realizing frequency mixing of a fractional order Fourier domain self-adaptive local oscillator and echo signals and random modulation of random codes on the mixed middle-tone signals, then sending the mixed middle-tone signals to an electric analog-to-digital converter for collection, and performing compressed sensing recovery and further recovery through digital signal processing to obtain a complete waveform.

The following describes a method for compressed sensing of a broadband signal capable of achieving large-range detection according to an embodiment of the present invention with reference to the accompanying drawings.

FIG. 6 is a flowchart of a method for compressed sensing of broadband signals that can achieve detection in a large range according to an embodiment of the present invention.

As shown in fig. 6, the method for sensing the compressed broadband signal capable of achieving large-range detection includes the following steps:

and step S1, loading the signal to be measured on the single-frequency light to generate an optical modulation signal.

And step S2, dividing the light modulation signal into two paths, and sampling the fractional order Fourier domain self-adaptive local oscillator and the random code to obtain two paths of light output signals.

And step S3, converting the optical output signal into an electrical output signal, and amplifying and filtering the electrical output signal to obtain two paths of results.

And step S4, acquiring and processing the two paths of results to obtain an imaging result of the signal to be detected.

It should be noted that the foregoing explanation of the system embodiment also applies to the method of this embodiment, and is not repeated here.

The broadband signal compressed sensing method capable of realizing large-distance detection provided by the embodiment of the invention can be applied to radar detection, and is characterized in that an echo to be received is loaded on a single-frequency optical carrier through electro-optical modulation and then is sent to an optical ternary frequency mixing module, frequency mixing of a fractional order Fourier domain self-adaptive local oscillator and the echo signal and random modulation of a random code on a mixed middle-tone signal are realized at the same time, the mixed middle-tone signal is sent to an electric analog-to-digital converter for collection, and compressed sensing recovery and further recovery are carried out through digital signal processing to obtain a complete waveform.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.