Radio communication signal automatic reconnaissance identification system and method, and storage medium

Abstract

The invention discloses an automatic radio communication signal reconnaissance and identification system and method and a storage medium. The system comprises an ultra-short wave communication signal reconnaissance antenna, a radio receiver and a mobile terminal. After the ultrashort wave communication signal reconnaissance antenna receives an electromagnetic signal sent by target radio frequency equipment, the electromagnetic signal is transmitted to the radio receiver through a feeder line, the radio receiver converts an analog electric signal into a digital signal, frequency conversion and sampling processing are carried out, and operation parameters of target reconnaissance identification software installed on the mobile terminal are set. The target reconnaissance identification software automatically controls the radio receiver to intercept communication signals, and the target reconnaissance identification software identifies and alarms in real time and displays the target type. By adopting the technical scheme of the invention, automatic reconnaissance and identification of a specific communication signal and a platform used by the specific communication signal are realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless signal detection, and particularly relates to a radio communication signal automatic reconnaissance and identification system and method, and a storage medium. Background Art

[0002] For the reconnaissance and identification of radio communication signals, it means using special equipment to search for and intercept communication signals, and to reconnaissance and identify the target by intercepting the target radio frequency signal. The identification mainly involves analyzing multiple characteristics of the signal. One is the frequency characteristic. Different communication systems have specific working frequency ranges. The second is the modulation method. The waveforms and other characteristics of signals with different modulation methods are different. Analyzing the modulation method can determine the nature of the signal. The third is the bandwidth of the signal. The spectral width occupied by the communication signal is also an important basis for distinguishing different signal types. By analyzing and judging the characteristics of radio communication signals, specific information such as the type and location of the target can be determined.

[0003] When the existing radio communication reconnaissance equipment conducts reconnaissance and identification on signals, it is necessary to manually screen the communication signals and repeatedly compare and judge the target attributes. Its timeliness and accuracy are not high, and it cannot achieve real-time and accurate reconnaissance and identification of the target. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a radio communication signal automatic reconnaissance and identification system and method, and a storage medium.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A radio communication signal automatic reconnaissance and identification system includes: a receiving antenna, a radio receiver, and a mobile terminal; wherein, after the electromagnetic signal emitted by the target radio frequency device is intercepted by the receiving antenna, it is transmitted to the radio interception receiver through a feeder. The target reconnaissance and identification software built in the mobile terminal controls the radio receiver to perform analog-to-digital conversion on the electromagnetic signal through a connection line, automatically detects and identifies the communication signal, and determines the type of the platform to which it belongs.

[0007] Preferably, the receiving antenna is a VHF communication signal reconnaissance antenna.

[0008] Preferably, after the VHF communication signal reconnaissance antenna receives the electromagnetic signal emitted by the target radio frequency device, it is transmitted to the radio receiver through a feeder. The radio receiver converts the analog electrical signal into a digital signal, and performs frequency conversion and sampling processing. Set the operating parameters of the target reconnaissance and identification software installed on the mobile terminal. The target reconnaissance and identification software automatically controls the radio receiver to intercept the communication signal, and the target reconnaissance and identification software displays the target type in real-time with an alarm.

[0009] The present invention also provides a radio communication signal automatic reconnaissance and identification method, including:

[0010] Step S1. After the electromagnetic signal emitted by the target radio device is intercepted by the receiving antenna, it is transmitted to the radio receiver through the feeder.

[0011] Step S2. The target reconnaissance and identification software built into the mobile terminal controls the radio receiver to perform analog-to-digital conversion on the electromagnetic signal through the connection line, automatically detects and identifies the communication signal, and determines the type of the platform to which it belongs.

[0012] Preferably, the receiving antenna is a VHF communication signal reconnaissance antenna.

[0013] Preferably, in Step S2, after the VHF communication signal reconnaissance antenna receives the electromagnetic signal emitted by the target radio device, it is transmitted to the radio receiver through the feeder. The radio receiver converts the analog electrical signal into a digital signal, and performs frequency conversion and sampling processing. Set the operating parameters of the target reconnaissance and identification software installed on the mobile terminal. The target reconnaissance and identification software automatically controls the radio receiver to intercept the communication signal, and the target reconnaissance and identification software displays the target type in real-time with an alarm.

[0014] The present invention also provides a storage medium, on which a computer program is stored, and the computer program executes the automatic reconnaissance and identification method for radio communication signals when running.

[0015] The present invention adopts intelligent detection technology. According to the parameter characteristics of known target communication signals, it automatically reconnoiters and identifies specific communication targets, and can analyze and obtain information such as the type and azimuth of the target platform. The present invention can manually set the target signal parameters, does not require manual operation and analysis during the reconnaissance and identification process, and can automatically reconnoiter and identify basic information such as the type and azimuth of specific targets. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0017] Figure 1 It is a schematic structural diagram of the automatic reconnaissance and identification system for radio communication signals according to the embodiment of the present invention. DETAILED DESCRIPTION

[0018] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0019] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] Embodiment 1:

[0021] As Figure 1 shown, an embodiment of the present invention provides an automatic radio communication signal reconnaissance and identification system, including: a receiving antenna, a radio receiver, and a mobile terminal. The receiving antenna is a VHF communication signal reconnaissance antenna, and the mobile terminal is a laptop computer. After the VHF communication signal reconnaissance antenna receives the electromagnetic signal emitted by the target radio frequency device, it is transmitted to the radio receiver through a feeder. The radio receiver converts the analog electrical signal into a digital signal and performs frequency conversion and sampling processing. Set the operating parameters of the target reconnaissance and identification software installed on the mobile terminal, and the target reconnaissance and identification software automatically controls the radio receiver to perform communication signal reception. The target reconnaissance and identification software displays the target type in real-time with an alarm. The target reconnaissance and identification software includes: a parameter setting column, a spectrogram display area, a reconnaissance and identification display area, and a back-end display area.

[0022] As an implementation manner of the embodiment of the present invention, the VHF communication signal receiving antenna is a discone antenna. This type of antenna is composed of 8 long wires and 8 short wires connected together, with their respective orientations evenly distributed in space. The whole is connected together in a discone shape. When the wires are in the electromagnetic space and encounter electromagnetic signals, the magnetic lines of force in the alternating electromagnetic field cut the wires, and a certain alternating voltage - electromotive force is excited at both ends of the wires, and its frequency is the same as the transmitting frequency.

[0023] As an implementation manner of the embodiment of the present invention, the radio receiver converts the analog electrical signal into a digital signal and performs frequency conversion and sampling processing specifically as follows: The signal within the specified bandwidth in the 2MHz - 6GHz frequency band enters the ultra-wideband communication signal real-time receiving and processing system device through the antenna or the RF front end. The broadband RF receiving module receives the control parameters of the broadband signal real-time processing module, and receives the broadband signal of the specified frequency according to the set parameters. After two-stage frequency conversion, amplification, and filtering processing, a broadband intermediate frequency signal with a frequency of 153.6MHz is output. The broadband signal real-time processing module receives the broadband intermediate frequency signal output by the broadband RF receiving module, and is converted into a digital signal of 250Msps after being sampled by a high-speed ADC.

[0024] As an implementation manner of an embodiment of the present invention, the reconnaissance and recognition process of the target reconnaissance and recognition software includes:

[0025] Step S1: Determine the carrier position in the spectrum

[0026] 1.1 Sample the received time-domain signal s(t) through A / D at a sampling rate of fs to obtain a discrete time-domain signal sequence s(n), where n = 0, 1, 2,... is a natural number. In practical applications, a large amount of data can be collected to improve the accuracy of estimation;

[0027] 1.2 Segment the time-domain sequence s(n) into M segments, each segment having a length of N, where N is generally a power of 2. Perform an N-point FFT transform on each segment of data and take the modulus and square to obtain the power spectrum Pm(f) of each segment, where m = 1, 2,..., M. After accumulating the power spectra and averaging, to offset the influence of part of the noise, obtain the power spectrum P(f) after the averaging operation:

[0028]

[0029] 1.3 Perform a logarithm operation on the power spectrum P(f) to obtain the power spectrum Plog(f) in the logarithmic domain:

[0030] P log (f) = 10 · log 10 (P(f))

[0031] Then perform a low-pass filtering operation on the power spectrum in the logarithmic domain to filter out the out-of-band noise and spikes on the spectrum, and obtain a smooth spectrum P smooth , and from it, according to the frequency band to be observed as expected, based on the start frequency f L and the cut-off frequency f H , intercept a power spectrum sequence of length I within a specific observation window, denoted as P I (i), where i = 1, 2,..., I;

[0032] 1.4 Perform a first-order difference operation on the data sequence P I (i) to obtain ΔP I . If the difference result is positive, record it as 1, and if the difference result is negative, record it as 0. In this way, a first-order difference sequence D 1 (i) with values of 1 and 0 can be obtained, where i = 1, 2,..., I - 1, and the continuous values of 1 and 0 represent the increasing or decreasing law of the data;

[0033] 1.5 Perform a second-order difference operation on the first-order difference sequence D 1 (i) to obtain a second-order difference sequence D 2(i), where i = 1, 2, ..., I - 2. D 2 In the (i) sequence, when reaching the inflection point of the convex function, the difference value becomes -1, and when reaching the inflection point of the concave function, the difference value becomes 1, and the values at other positions are all 0;

[0034] 1.6 To obtain the other two special positions of the carrier (the upper left corner and the lower right corner positions), a reverse scan is required, that is, first reverse the power spectrum data from beginning to end, and output the reverse as the input data for the scan. The steps are the same as the first scan. The obtained scan result is reversed again from beginning to end, which is the upper left corner and the lower right corner positions of the carrier.

[0035] Step S2, Carrier center frequency estimation

[0036] 2.1 Read the multi-carrier power spectrum data P smooth , and according to the two key positions of each scanned carrier, that is, the lower left corner point and the lower right corner point of the carrier, read the power spectrum data between the two points as the power spectrum of a single carrier. Let the power spectrum of the m-th carrier be P smooth_m ;

[0037] 2.2 Perform a difference on the logarithmic domain power spectrum P smooth_m to obtain a first-order difference sequence ΔP(i), and record the positions corresponding to the maximum and minimum values of ΔP(i) respectively, which are the two positions l smooth_m and l 1 with the largest absolute values of the slopes of the power spectrum P 2 . Since it is a single-carrier signal without interference, these two positions should be the two center positions of the carrier,

[0038] 2.3 Then the estimated theoretical center frequency f c0_est of the carrier is:

[0039]

[0040] 2.4 Select points with the number of points being k smooth_m from the spectrum P m , where km ∈ {0, 1, 2, ..., N / 2 - 1}, and satisfy |km / T - f c0_est | ≤ 1 / 2T, where T is the sampling time length, f c0_est is the estimated frequency, and N is the number of sampling points;

[0041] 2.5 Select M frequency domain points, where M satisfies M ≤ min{2km + 1, 2(N / 2 - km) - 1}. If the inequality -1 / 2T ≤ km / T - f c0_est ≤ 0 holds, execute 2.5.1. If the inequality 0 ≤ km / T - f c0_est ≤ 1 / 2T holds, execute 2.5.2;

[0042] 2.5.1 If M is even, then \(k_{2n}=k_{m + n}\), where \(n = 1, 2,\cdots,\frac{M}{2}\), and \(k_{2n + 1}=k_{m - n}\), where \(n = 1, 2,\cdots,\frac{M}{2}-1\); if M is odd, then \(k_{2n}=k_{m + n}\), where \(n = 1, 2,\cdots,\frac{M - 1}{2}\), and \(k_{2n + 1}=k_{m - n}\), where \(n = 1, 2,\cdots,\frac{M - 1}{2}-1\);

[0043] 2.5.2 If M is even, then \(k_{2n}=k_{m - n}\), where \(n = 1, 2,\cdots,\frac{M}{2}\), and \(k_{2n + 1}=k_{m + n}\), where \(n = 1, 2,\cdots,\frac{M}{2}-1\); if M is odd, then \(k_{2n}=k_{m - n}\), where \(n = 1, 2,\cdots,\frac{M - 1}{2}\), and \(k_{2n + 1}=k_{m + n}\), where \(n = 1, 2,\cdots,\frac{M - 1}{2}-1\);

[0044] 2.6 Then the rough estimate value \(f\) of the center frequency cestr is:

[0045]

[0046] 2.7 For \(f\) cestr perform frequency offset correction. Down-convert the single carrier signal through \(f\) c_estr to the complex baseband. Down-sample the complex baseband signal at the sampling frequency \(f\) s_down and calculate the fourth power spectrum of the signal. Find the spectral peak position \(L_{peak}\), then the frequency offset \(d\) f is:

[0047] \(d\) f \(=L\) peak \(\cdot f\) s down / (4N), where N represents the number of FFT points.

[0048] 2.8 After obtaining \(d\) f , compensate the estimated frequency to obtain the final frequency estimate value \(f\) c_est :

[0049] \(f\) c_est \(=f\) c_estr \(+d\) f

[0050] Step S3, Carrier Bandwidth Estimation

[0051] 3.1 Assume that the number of carriers in the power spectrum sequence \(P_I(i)\) of the smoothed multi-carrier signal is Q. Extract the power spectrum data between the upper left position and the upper right position of each carrier in the multi-carrier signal, denoted as \(P_q(i)\), where \(q = [1, 2,\cdots,Q]\);

[0052] 3.2 Take the average of each group of data Pq(i) as the peak value of the power spectrum of this carrier, denoted as Pq. The power spectrum data P between the lower left corner position and the upper left corner position of this carrier ql1 and the power spectrum data P between the upper right corner position and the lower right corner position of the carrier ql2 to find the position of the point with the value closest to P q-3 , denoted as l qd and l qu ;

[0053] 3.3 Then the bandwidth Bq of this signal can be obtained according to the following formula:

[0054]

[0055] Step S4, modulation mode recognition

[0056] From the perspective of time-domain characteristics, the five modulation modes of BPSK, QPSK, 8PSK, 16QAM, and 16APSK can be divided into two categories, namely constant envelope modulation and non-constant envelope modulation. Among them, BPSK, QPSK, and 8PSK belong to constant envelope modulation, while 16QAM and 16APSK belong to non-constant envelope modulation. Therefore, two types of signals can be distinguished based on the envelope characteristics. In the embodiments of the present invention, the ratio of the envelope variance to the mean square is selected as the characteristic parameter for distinguishing the two modulation modes. Theoretically, the ratio of the envelope variance to the mean square of the MPSK modulation signal is equal to 0, while the ratio of the envelope variance to the mean square of the 16QAM and 16APSK modulation signals is greater than 0.

[0057] Secondly, the second-order cumulant and the fourth-order cumulant are used for more detailed discrimination.

[0058] Second-order cumulant:

[0059] C 20 = E[y(n)·y(n)]

[0060] C 20 = E[y(n)·y*(n)]

[0061] Fourth-order cumulant:

[0062]

[0063] C 41 = cum[y(n),y(n),y(n),y * (n)] = E[y(n)·y(n)·y(n)··y * (n)] - 3C 20 C 21

[0064]

[0065] Sixth-order cumulant:

[0066]

[0067] Definition of characteristic parameters:

[0068]

[0069] For the characteristic parameter F1 of BPSK, QPSK, and 16QAM modulations, all satisfy |F1 - 1| 2 <|F1 - 0| 2 For 8PSK and 16APSK modulations, all satisfy |F1 - 1| 2 >|F1 - 0| 2 Furthermore, the specific modulation mode of the carrier can be determined through different ranges of the F2 value.

[0070] The display interface in the target reconnaissance and recognition software includes: a parameter setting bar, a spectrogram display area, a reconnaissance and recognition display area, and a back-end display area; among them, the parameter setting bar includes center frequency setting, reference level setting, receive bandwidth (sampling rate) setting, spectrogram color setting, and IQ data acquisition and saving path setting; the upper half of the spectrogram display area is the signal energy waterfall diagram, and the lower half is the waveform spectrogram; the reconnaissance and recognition display area is used to display the intercepted signal time, center frequency, signal bandwidth, signal system, and recognition times; the back-end display area is used to display the signal system detection results: time, front-end position of the system, number of detections, signal system, frequency, bandwidth, and corresponding waterfall diagram.

[0071] In the embodiment of the present invention, through the target parameters of multiple types of communication signals, the key features of the above radio frequency signals are automatically detected and extracted, achieving the purpose of automatically reconnoitering and recognizing the target.

[0072] Embodiment 2:

[0073] The embodiment of the present invention also provides an automatic reconnaissance and recognition method for radio communication signals, including:

[0074] Step S1: After the electromagnetic signal emitted by the target radio frequency device is intercepted by the receiving antenna, it is transmitted to the radio receiver through the feeder;

[0075] Step S2: The target reconnaissance and recognition software built in the mobile terminal controls the radio receiver through the connection line to perform analog-to-digital conversion on the electromagnetic signal, automatically detects and recognizes the communication signal, and determines the type of the platform to which it belongs.

[0076] As an implementation manner of the embodiment of the present invention, the receiving antenna is a VHF communication signal reconnaissance antenna.

[0077] As an implementation manner of an embodiment of the present invention, in step S2, after the ultra-short wave communication signal reconnaissance antenna receives the electromagnetic signal emitted by the target radio frequency device, it is transmitted to the radio receiver through the feeder. The radio receiver converts the analog electrical signal into a digital signal, and performs frequency conversion and sampling processing. Set the operating parameters of the target reconnaissance and identification software installed on the mobile terminal. The target reconnaissance and identification software automatically controls the radio receiver to intercept the communication signal, and the target reconnaissance and identification software alarms and displays the target type in real time.

[0078] Embodiment 3:

[0079] The embodiment of the present invention further provides a storage medium, on which a computer program is stored, and the computer program executes the automatic reconnaissance and identification method of radio communication signals when running.

[0080] The above-described embodiments are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A radio communication signal automatic detection and identification system, characterized in that: include: Receiving antenna, radio receiver and mobile terminal; the electromagnetic signal emitted by the target radio frequency device is intercepted by the receiving antenna and transmitted to the radio receiver through the feeder. The target reconnaissance and identification software built into the mobile terminal controls the radio receiver through the connecting line to perform analog-to-digital conversion on the electromagnetic signal, automatically detects and identifies the communication signal, and determines the type of platform to which it belongs.

2. The radio communication signal automatic detection and identification system according to claim 1, characterized in that: The receiving antenna is an ultra-short wave communication signal reconnaissance antenna.

3. The radio communication signal automatic detection and identification system according to claim 2, characterized in that: After the ultra-short wave communication signal reconnaissance antenna receives the electromagnetic signal emitted by the target radio frequency device, it is transmitted to the radio receiver via the feeder. The radio receiver converts the analog electrical signal into a digital signal, and performs frequency conversion and sampling processing. The operating parameters of the target reconnaissance and identification software installed on the mobile terminal are set. The target reconnaissance and identification software automatically controls the radio receiver to intercept the communication signal. The target reconnaissance and identification software displays the target type in real time with an alarm.

4. A method for automatic detection and identification of radio communication signals, characterized in that: include: Step S1, the electromagnetic signal emitted by the target radio frequency device is intercepted by the receiving antenna and transmitted to the radio receiver through the feeder; Step S2: The built-in target reconnaissance and recognition software of the mobile terminal controls the radio receiver through the connecting line to perform analog-to-digital conversion on the electromagnetic signal, automatically detects and recognizes the communication signal, and determines the platform type.

5. The method for automatic detection and identification of radio communication signals according to claim 4, characterized in that: The receiving antenna is an ultra-short wave communication signal reconnaissance antenna.

6. The method for automatic detection and identification of radio communication signals according to claim 5, characterized in that: In step S2, after the ultra-short wave communication signal reconnaissance antenna receives the electromagnetic signal emitted by the target radio frequency device, it is transmitted to the radio receiver via the feeder. The radio receiver converts the analog electrical signal into a digital signal, and performs frequency conversion and sampling processing. The operating parameters of the target reconnaissance and identification software installed on the mobile terminal are set. The target reconnaissance and identification software automatically controls the radio receiver to intercept the communication signal, and the target reconnaissance and identification software alarms in real time to display the target type.

7. A storage medium, characterized in that: The storage medium stores a computer program, which, when running, executes the method for automatic reconnaissance and identification of radio communication signals as described in any one of claims 4 to 6.

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