阅读说明：本技术 一种动态背景信号生成系统 (Dynamic background signal generation system ) 是由 王满喜 钱志升 朱健东 陆科宇 李坤 王得旺 于 2021-07-30 设计创作，主要内容包括：本发明公开一种动态背景信号生成系统,其包括监测接收模块、信息处理计算模块、信号发射模块；其中,监测接收模块,用于对目标信号进行侦察感知,识别信号载频、调制类型、带宽信息,生成目标信号描述子；信息处理计算模块,用于制定不同复杂度等级的复杂背景信号,基于目标信号描述子,生成背景信号的参数配置文件；信号发射模块,用于产生满足参数配置文件要求的不同频率、幅度、调制样式的背景信号。本发明能够提高复杂电磁环境构建能力,便于更好地检验设备复杂电磁环境下的工作性能。(The invention discloses a dynamic background signal generation system, which comprises a monitoring receiving module, an information processing and calculating module and a signal transmitting module, wherein the monitoring receiving module is used for receiving a signal transmitted by a user; the monitoring receiving module is used for carrying out reconnaissance perception on a target signal, identifying signal carrier frequency, modulation type and bandwidth information and generating a target signal descriptor; the information processing and calculating module is used for formulating complex background signals with different complexity levels and generating a parameter configuration file of the background signals based on the target signal descriptor; and the signal transmitting module is used for generating background signals with different frequencies, amplitudes and modulation patterns meeting the requirements of the parameter configuration file. The invention can improve the construction capability of the complex electromagnetic environment and is convenient for better checking the working performance of the equipment in the complex electromagnetic environment.)

1. A dynamic background signal generation system, characterized by: the system comprises a monitoring receiving module, an information processing and calculating module and a signal transmitting module; wherein the content of the first and second substances,

the monitoring receiving module is used for carrying out reconnaissance perception on the target signal, identifying signal carrier frequency, modulation type and bandwidth information and generating a target signal descriptor;

the information processing and calculating module is used for formulating complex background signals with different complexity levels and generating a parameter configuration file of the background signals based on the target signal descriptor;

and the signal transmitting module is used for generating background signals with different frequencies, amplitudes and modulation patterns meeting the requirements of the parameter configuration file.

2. The dynamic background signal generation system of claim 1, wherein: the monitoring receiving module mainly comprises a basic hardware unit, a main control unit, a GPU unit, a high-speed signal acquisition processing unit, a high-speed data storage unit, a down-conversion unit and a local oscillator unit; wherein the content of the first and second substances,

the basic hardware unit consists of a high-speed backboard, a case, a power supply, a fan, a power supply and a fan control unit, wherein the high-speed backboard provides a physical interconnection channel among all the functional units;

the main control unit is mainly used for analyzing the instruction and sending the instruction to each functional unit to complete the control of the working state of each functional unit;

the GPU unit is mainly used for performing high-speed computation on complex data, is interconnected with the main control unit and realizes the functions of real-time signal analysis and graphic display of big data;

the high-speed signal acquisition and processing unit is mainly used for acquiring externally input intermediate-frequency signals and transmitting data to the main control unit through a PCIe interface;

the down-conversion unit is mainly used for converting the radio-frequency signals into intermediate-frequency signals and sending the intermediate-frequency signals to the high-speed signal acquisition and processing unit;

the local oscillation unit is mainly used for generating local oscillation signals of a required frequency band and providing a frequency conversion local oscillation interface for the down-conversion unit;

the high-speed data storage unit is mainly used for high-speed recording of data files.

3. The dynamic background signal generation system of claim 1, wherein: the signal transmitting module comprises a basic hardware unit, a main control unit, a clock interface unit, a signal generating unit, a high-speed storage unit and a signal conditioning and monitoring unit; wherein the content of the first and second substances,

the basic hardware unit comprises a case, a back plate and a power supply, is the basis for the operation of the whole signal transmitting module and provides a power supply and a data transmission channel for each functional unit;

the main control unit is mainly used for controlling the whole signal transmitting module, providing a signal transmitter hardware control software running platform and interconnecting with the clock interface unit through PCIe;

the clock interface unit is mainly used for controlling and transmitting data between the main control unit and the signal generating unit;

the signal generation unit is mainly used for generating analog signals or reading data from the high-speed storage unit through an SRIO 8x interface to generate signals;

the high-speed storage unit is mainly used for storing signal parameters and signal data and providing the signal data in a playback mode;

and the signal conditioning and monitoring unit is mainly used for filtering and amplifying the signals output by the signal generating unit and coupling the output signals to provide an observation channel.

4. A dynamic background signal generation method implemented by the dynamic background signal generation system according to any one of claims 1 to 3, characterized in that: which comprises the following steps:

s1, detecting and sensing the target signal, and acquiring carrier frequency, modulation type and bandwidth information of the target signal;

s2, formulating a background signal generation rule, and generating parameter configuration information required by a signal generation module according to a target signal reconnaissance sensing result; the operation method comprises the following steps:

s2.1, making a background signal generation rule

(1) The key frequency band bandwidth complexity setting principle is as follows: acquiring the frequency range and the occurrence probability information of a target signal according to the target signal reconnaissance sensing result, and determining a target signal key frequency band;

L_i＝(f_high-f_low)×x％

in the formula, L_iFor simulated focal region bandwidth, f_highAt the high end of the working frequency band or at the high end of the frequency hopping bandwidth, f_lowIs the low band of the working frequency band or the low end of the frequency hopping bandwidth, x% is set according to the scale of the electromagnetic environment;

(2) signal number complexity setting principle: setting different signal quantities according to the key frequency band bandwidth and the channel bandwidth of the tested object and the complexity of different levels;

in the formula, w_iA channel bandwidth for the communication device;

(3) signal strength complexity setting principle: the fluctuation range of the background signal strength reflects the interference degree of the background signal on the tested equipment in an energy domain, and the signal strength complexity setting method comprises the following steps:

E_n＝P+P*x_P_n

wherein P is the target signal strength, E_nTaking the background signal intensity as x _ P _ n, and taking the complex electromagnetic environment intensity factors of different levels as x _ P _ n;

(4) signal pattern complexity setting principle: the setting of the signal pattern complexity is determined based on various electronic equipment patterns faced by the tested equipment, the characteristics of presenting diversity along with the improvement of the complexity are reflected, and the signal pattern settings of I-level, II-level and III-level complex electromagnetic environments are gradually complicated according to the test requirements;

s2.2, making a background signal generation rule

Judging whether parameters such as carrier frequency, modulation type and the like in the reconnaissance sensing result are changed, and if so, regenerating parameter configuration information according to the background signal generation rule in the step S2.1; if no change exists, the previous parameter configuration information is kept, and only the signal intensity is refreshed;

and S3, generating a signal according to the parameter configuration information.

5. The dynamic background signal generation method according to claim 4, wherein: in step S1, the implementation method is as follows:

s1.1, carrier frequency estimation of target signal

Estimating the frequency by adopting a zero-crossing detection method of a time domain; the zero-crossing detection method is to perform zero-crossing detection on the input signal sequence x (n), if x (n)_i) And x (n)_i+1) have different signs, it can be determined that the time period (n) is the same_i/F_s，(n_i+1)/F_s) There is a zero point therebetween, wherein F_sRepresenting the sampling rate, the position of the zero point being calculated using a linear interpolation formula

Forming a zero-crossing sequence { α (i) } from the time instants of the detected zero points, where i is 1,2, …, M, where M is the number of detected zero-crossing points; defining the sequence of first order differences of { alpha (i) } as a sequence of zero-crossing spacings { beta (i) }, i.e.

β(i)＝α(i+1)-α(i)，i＝1，2，…，M-1

For a single frequency signal in noise, the distance between two zeros is

ε (i) is a random number obeying a zero-mean distribution, F_cRepresenting the signal frequency; is composed of E [ alpha ], [ betaε(i)]Get 0 ═ toThus, the frequency F is estimated from the mean value of β (i)_cI.e. by

S1.2, identification of modulation type of target signal

S1.21, firstly, carrying out down-conversion processing on a signal by using the carrier frequency estimation result in the step S1.1;

s1.22, selecting modulation signal characteristic parameters, and identifying a digital characteristic set consisting of amplitude modulation, frequency modulation, amplitude shift keying, frequency shift keying and binary phase shift keying by adopting a decision number method; the classification characteristics comprise a maximum spectral density value of zero-center normalized instantaneous amplitude, a standard deviation of zero-center nonlinear instantaneous phase, a spectral symmetry degree, a standard deviation of zero-center nonlinear instantaneous phase absolute value, a standard deviation of zero-center normalized instantaneous amplitude absolute value and a standard deviation of zero-center normalized instantaneous frequency absolute value; the method specifically comprises the following steps:

(1) zero center normalized instantaneous amplitude of the maximum gamma of the spectral density_max

In the formula, N_sCounting the number of sampling points; a is_cn(i) The sequence after taking the zero center for the normalized instantaneous amplitude is calculated by

a_cn(k)＝a_n(k)-1

Wherein a (k) is a sequence of sampled signals, m_aIs the average value of the signal sequence, a_n(k) Is a signal instantaneous amplitude sequence;

(2) zero center nonlinear instantaneous phase standard deviation σ_dp

In the formula, a_tA strong signal decision threshold, c is the number of strong signals in the sample sequence,is a non-linear instantaneous phase sequence, sigma, subjected to zero-center normalization_dpIndicating the degree of change of the nonlinear phase;

(3) degree of spectral symmetry P

In the formula, x (k) is an FFT sequence obtained after fourier transform of the signal x (k), and N is a corresponding sequence number of the carrier frequency point in the FFT sequence;

(4) zero center non-linear instantaneous phase absolute value standard deviation sigma_ap

In the formula, a_tA threshold for strong signal determination, c the number of strong signals in the sample sequence,is a non-linear instantaneous phase sequence processed by zero-crossing center normalization;

(5) zero center normalized instantaneous amplitude absolute value standard deviation sigma_aa

(6) Zero center normalized instantaneous frequency absolute value standard deviation sigma_af

In the formula (f)_N(k) Is a zero-center normalized instantaneous frequency sequence;

s1.23, identifying signals with different modulation patterns by adopting a modulation identification method based on signal instantaneous characteristics; the classifier in the modulation recognition system adopts a decision tree classifier.

6. The dynamic background signal generation method according to claim 4, wherein: in step S3, the background signal generation mode includes two modes, i.e., a signal playback mode and an autonomous generation mode; wherein the content of the first and second substances,

and (3) standardizing a sample set signal playback mode: after receiving and analyzing the parameter configuration information sent by the information processing and calculating module, the main control unit of the signal transmitting module retrieves baseband signal sample library data from a database according to the parameters and stores the baseband signal sample library data in a high-speed storage unit, and when playback output is needed, the main control unit reads the data from the high-speed storage unit to DAC (digital-to-analog converter) for playback output and simultaneously adjusts the frequency and the power of the signal;

an autonomous generation mode: and after receiving and analyzing the parameter configuration information sent by the information processing and calculating module, the main control unit of the signal transmitting module adjusts the parameters of the generated signals in the local signal transmitting module according to the parameters, and then sends the parameters to the signal generating unit to realize the generation of the signals.

Technical Field

The invention relates to the technical field of communication signal processing, in particular to a dynamic background signal generation system.

Background

In the test of the communication equipment, in order to check the adaptability of the equipment in a complex electromagnetic environment, a vivid complex background signal environment needs to be created. The working state, index parameters and the like of the equipment are tested in a vivid background signal environment, and a real and credible technical basis is provided for the actual use of the equipment. If the background signal environment is generated by using the entity equipment in a spatial distribution and accumulation way, the cost is high, the efficiency is low, the signal density under the real condition is difficult to obtain, and the complex electromagnetic environment test requirement of the communication equipment with the cognitive function is difficult to meet.

Through previous complex electromagnetic environment equipment tests, the existing background signal simulation method has the advantage that a high-density and repeatable signal environment is easy to generate. However, the parameters such as carrier frequency point, modulation style, amplitude and the like of the background signal simulation equipment cannot be controlled in real time at present, and waveform data can be regenerated and stored in a memory only by calculating the parameters such as frequency, modulation style and the like of a defined signal in advance when the background is switched. That is to say, the static background is a "dead background", and cannot meet the test requirement of the next communication device with cognitive function.

Aiming at future communication equipment with cognitive function, a test environment must be changed into an electromagnetic spectrum game environment from an original signal generation accompanying environment, and background signal simulation of the electromagnetic spectrum game environment can adaptively adjust frequency and parameters in real time according to emission frequency and modulation parameters of a target signal to form a game situation together with the target signal. The existing background signal simulation equipment has no scouting perception capability, the parameters of carrier frequency points, modulation patterns, amplitudes and the like of generated signals cannot be controlled in real time, background signal generation rules with different complexity levels are lacked, the generated signals can only be generated by planning in advance, and the instantaneity is poor.

Disclosure of Invention

In order to solve the problem that the background signal cannot be detected, sensed, interacted and controlled in real time in the prior art, the invention aims to provide a dynamic background signal generation system and a generation method, which can enable the background signal to self-adaptively adjust parameters such as frequency and the like in real time according to the emission frequency and the modulation pattern of a target signal, quickly generate background signals with different complexity levels, and establish a game interaction environment together with test equipment, thereby improving the construction capability of a complex electromagnetic environment and facilitating better inspection of the working performance of the equipment in the complex electromagnetic environment.

In order to achieve the purpose, the invention adopts the following technical scheme:

a dynamic background signal generation system comprises a monitoring receiving module, an information processing calculation module and a signal transmitting module; wherein the content of the first and second substances,

the monitoring receiving module is used for carrying out reconnaissance perception on the target signal, identifying signal carrier frequency, modulation type and bandwidth information and generating a target signal descriptor;

the information processing and calculating module is used for formulating complex background signals with different complexity levels and generating a parameter configuration file of the background signals based on the target signal descriptor;

and the signal transmitting module is used for generating background signals with different frequencies, amplitudes and modulation patterns meeting the requirements of the parameter configuration file.

Furthermore, the monitoring receiving module mainly comprises a basic hardware unit, a main control unit, a GPU unit, a high-speed signal acquisition and processing unit, a high-speed data storage unit, a down-conversion unit and a local oscillator unit; wherein the content of the first and second substances,

the basic hardware unit consists of a high-speed backboard, a case, a power supply, a fan, a power supply and a fan control unit, wherein the high-speed backboard provides a physical interconnection channel among all the functional units;

the main control unit is mainly used for analyzing the instruction and sending the instruction to each functional unit to complete the control of the working state of each functional unit;

the GPU unit is mainly used for performing high-speed computation on complex data, is interconnected with the main control unit and realizes the functions of real-time signal analysis and graphic display of big data;

the high-speed signal acquisition and processing unit is mainly used for acquiring externally input intermediate-frequency signals and transmitting data to the main control unit through a PCIe interface;

the down-conversion unit is mainly used for converting the radio-frequency signals into intermediate-frequency signals and sending the intermediate-frequency signals to the high-speed signal acquisition and processing unit;

the local oscillation unit is mainly used for generating local oscillation signals of a required frequency band and providing a frequency conversion local oscillation interface for the down-conversion unit;

the high-speed data storage unit is mainly used for high-speed recording of data files.

Furthermore, the signal transmitting module comprises a basic hardware unit, a main control unit, a clock interface unit, a signal generating unit, a high-speed storage unit and a signal conditioning and monitoring unit; wherein the content of the first and second substances,

the basic hardware unit comprises a case, a back plate and a power supply, is the basis for the operation of the whole signal transmitting module and provides a power supply and a data transmission channel for each functional unit;

the main control unit is mainly used for controlling the whole signal transmitting module, providing a signal transmitter hardware control software running platform and interconnecting with the clock interface unit through PCIe;

the clock interface unit is mainly used for controlling and transmitting data between the main control unit and the signal generating unit;

the signal generation unit is mainly used for generating analog signals or reading data from the high-speed storage unit through an SRIO 8x interface to generate signals;

the high-speed storage unit is mainly used for storing signal parameters and signal data and providing the signal data in a playback mode;

and the signal conditioning and monitoring unit is mainly used for filtering and amplifying the signals output by the signal generating unit and coupling the output signals to provide an observation channel.

A dynamic background signal generation method is generated by the dynamic background signal generation system, and comprises the following steps:

s1, detecting and sensing the target signal, and acquiring carrier frequency, modulation type and bandwidth information of the target signal;

s2, formulating a background signal generation rule, and generating parameter configuration information required by a signal generation module according to a target signal reconnaissance sensing result; the operation method comprises the following steps:

s2.1, making a background signal generation rule

(1) The key frequency band bandwidth complexity setting principle is as follows: acquiring the frequency range and the occurrence probability information of a target signal according to the target signal reconnaissance sensing result, and determining a target signal key frequency band;

L_i＝(f_high-f_low)×x％

in the formula, L_iFor simulated focal region bandwidth, f_highAt the high end of the working frequency band or at the high end of the frequency hopping bandwidth, f_lowIs the low band of the working frequency band or the low end of the frequency hopping bandwidth, x% is set according to the scale of the electromagnetic environment;

(2) signal number complexity setting principle: setting different signal quantities according to the key frequency band bandwidth and the channel bandwidth of the tested object and the complexity of different levels;

in the formula, w_iA channel bandwidth for the communication device;

(3) signal strength complexity setting principle: the fluctuation range of the background signal strength reflects the interference degree of the background signal on the tested equipment in an energy domain, and the signal strength complexity setting method comprises the following steps:

E_n＝P+P*x_P_n

wherein P is the target signal strength, E_nTaking the background signal intensity as x _ P _ n, and taking the complex electromagnetic environment intensity factors of different levels as x _ P _ n;

(4) signal pattern complexity setting principle: the setting of the signal pattern complexity is determined based on various electronic equipment patterns faced by the tested equipment, the characteristics of presenting diversity along with the improvement of the complexity are reflected, and the signal pattern settings of I-level, II-level and III-level complex electromagnetic environments are gradually complicated according to the test requirements;

s2.2, making a background signal generation rule

Judging whether parameters such as carrier frequency, modulation type and the like in the reconnaissance sensing result are changed, and if so, regenerating parameter configuration information according to the background signal generation rule in the step S2.1; if no change exists, the previous parameter configuration information is kept, and only the signal intensity is refreshed;

and S3, generating a signal according to the parameter configuration information.

Further, in the above step S1, the implementation method is as follows:

s1.1, carrier frequency estimation of target signal

Estimating the frequency by adopting a zero-crossing detection method of a time domain; the zero-crossing detection method is to perform zero-crossing detection on the input signal sequence x (n), if x (n)_i) And x (n)_i+1) have different signs, it can be determined that the time period (n) is the same_i/F_s,(n_i+1)/F_s) There is a zero point therebetween, wherein F_sRepresenting the sampling rate, the position of the zero point being calculated using a linear interpolation formula

Forming a zero-crossing sequence { α (i) } from the time instants of the detected zero points, where i is 1,2, …, M, where M is the number of detected zero-crossing points; defining the sequence of first order differences of { alpha (i) } as a sequence of zero-crossing spacings { beta (i) }, i.e.

β(i)＝α(i+1)-α(i),i＝1,2,…,M-1

For a single frequency signal in noise, the distance between two zeros is

ε (i) is a random number obeying a zero-mean distribution, F_cRepresenting the signal frequency; from E [ epsilon (I)]Get 0 ═ toThus, the frequency f is estimated from the mean value of β (I)_CI.e. by

S1.2, identification of modulation type of target signal

S1.21, firstly, carrying out down-conversion processing on a signal by using the carrier frequency estimation result in the step S1.1;

s1.22, selecting modulation signal characteristic parameters, and identifying a digital characteristic set consisting of amplitude modulation, frequency modulation, amplitude shift keying, frequency shift keying and binary phase shift keying by adopting a decision number method; the classification characteristics comprise a maximum spectral density value of zero-center normalized instantaneous amplitude, a standard deviation of zero-center nonlinear instantaneous phase, a spectral symmetry degree, a standard deviation of zero-center nonlinear instantaneous phase absolute value, a standard deviation of zero-center normalized instantaneous amplitude absolute value and a standard deviation of zero-center normalized instantaneous frequency absolute value; the method specifically comprises the following steps:

(1) zero center normalized instantaneous amplitude of the maximum gamma of the spectral density_max

In the formula, N_sCounting the number of sampling points; a is_cn(i) The sequence after taking the zero center for the normalized instantaneous amplitude is calculated by

a_cn(k)＝a_n(k)-1

Wherein a (k) is a sequence of sampled signals, m_aIs the average value of the signal sequence, a_n(k) Is a signal instantaneous amplitude sequence;

(2) zero center nonlinear instantaneous phase standard deviation σ_dp

In the formula, a_tA strong signal decision threshold, c is the number of strong signals in the sample sequence,is a non-linear instantaneous phase sequence, sigma, subjected to zero-center normalization_dpRepresenting the degree of change of the nonlinear phase, and is used for identifying and classifying AM and DSB signals;

(3) degree of spectral symmetry P

In the formula, x (k) is an FFT sequence obtained after fourier transform of the signal x (k), and N is a corresponding sequence number of the carrier frequency point in the FFT sequence;

(4) zero center non-linear instantaneous phase absolute value standard deviation sigma_ap

In the formula, a_TA threshold for strong signal determination, c the number of strong signals in the sample sequence,is a nonlinear instantaneous phase sequence normalized by the zero-crossing center, which is used for identifying BPSK signals from { BPSK, QPSK, 2FSK, 4FSK };

(5) zero center normalized instantaneous amplitude absolute value standard deviation sigma_aa

In the formula, σ_aaMainly to distinguish between 2ASK and 4ASK signals, and_apin the same principle, the 2ASK signal amplitude is only two, and the zero center normalization instantaneous amplitude absolute value standard deviation sigma thereof_aa0 is approximately distributed; 4ASK signal amplitudes four, corresponding to parameter sigma_aa＞0；

(6) Zero center normalized instantaneous frequency absolute value standard deviation sigma_af

In the formula (f)_N(k) Is a zero-center normalized instantaneous frequency sequence, σ_afMainly used for distinguishing 2FSK and 4FSK signals;

s1.23, identifying signals with different modulation patterns by adopting a modulation identification method based on signal instantaneous characteristics; the classifier in the modulation recognition system adopts a decision tree classifier.

Further, in the step S3, the background signal generation mode includes two modes, i.e., a signal playback mode and an autonomous generation mode; wherein the content of the first and second substances,

and (3) standardizing a sample set signal playback mode: after receiving and analyzing the parameter configuration information sent by the information processing and calculating module, the main control unit of the signal transmitting module retrieves baseband signal sample library data from a database according to the parameters and stores the baseband signal sample library data in a high-speed storage unit, and when playback output is needed, the main control unit reads the data from the high-speed storage unit to DAC (digital-to-analog converter) for playback output and simultaneously adjusts the frequency and the power of the signal;

an autonomous generation mode: and after receiving and analyzing the parameter configuration information sent by the information processing and calculating module, the main control unit of the signal transmitting module adjusts the parameters of the generated signals in the local signal transmitting module according to the parameters, and then sends the parameters to the signal generating unit to realize the generation of the signals.

Due to the adoption of the technical scheme, the invention has the following advantages:

the dynamic background signal generation system adopts the monitoring module with the real-time reconnaissance and perception function to monitor and analyze a target signal, guides the signal generation of the signal transmitting module according to a signal analysis result and according to preset complex background signal generation rules of different levels, generates complex communication background signal environments with multiple radiation sources, multiple systems, wide frequency bands and high density, meets the requirements of communication equipment test and the like, improves the verisimilitude and the game performance of background signal simulation, and improves the testing capability of the complex electromagnetic environments of communication equipment.

Drawings

FIG. 1 is a block diagram of the dynamic background signal generation system of the present invention;

FIG. 2 is a schematic block diagram of a dynamic background signal generation system of the present invention;

FIG. 3 is a flow chart of the operation of the dynamic background signal generation system of the present invention;

fig. 4 is a block diagram of a signal transmitting module of the dynamic background signal generating system according to the present invention.

Detailed Description

The technical solution of the present invention will be further described in detail with reference to the accompanying drawings and examples.

As shown in fig. 1, the dynamic background signal generating system includes a monitoring receiving module, an information processing calculating module, and a signal transmitting module; wherein the content of the first and second substances,

the monitoring receiving module is used for carrying out reconnaissance perception on the target signal, identifying signal carrier frequency, modulation type and bandwidth information and generating a target signal descriptor;

the information processing and calculating module is used for formulating complex background signals with different complexity levels and generating a parameter configuration file of the background signals based on the target signal descriptor;

the signal transmitting module is used for generating background signals with different frequencies, amplitudes and modulation patterns meeting the requirements of the parameter configuration file;

the invention relates to a dynamic background signal generation system, which receives a target signal through a monitoring receiving module, automatically identifies and measures the information such as the frequency, the amplitude, the modulation mode and the like of the target signal, sends the results of automatic identification and parameter measurement to an information processing and calculating module, generates a background signal generation strategy file according to a selected background signal generation strategy algorithm and the results of identification and parameter measurement in the information processing and calculating module, sends the strategy file to a signal transmitting module, analyzes the strategy file generated by the background signal, generates a required background signal according to the analysis result, transmits the background signal, and finally realizes the construction of a dynamic background signal environment.

The monitoring receiving module is realized by adopting a PXIe architecture and mainly comprises a basic hardware unit, a main control unit, a GPU unit, a high-speed signal acquisition and processing unit, a high-speed data storage unit, a down-conversion unit and a local oscillator unit; wherein the content of the first and second substances,

the basic hardware unit consists of a high-speed backboard, a case, a power supply, a fan, a power supply and a fan control unit, wherein the high-speed backboard provides a physical interconnection channel among all the functional units and adopts a standard PXIe 3U 10 slot structure;

the main control unit is mainly used for analyzing the instruction and sending the instruction to each functional unit to complete the control of the working state of each functional unit;

the GPU unit is mainly used for performing high-speed computation on complex data, is interconnected with the main control unit and realizes the functions of real-time signal analysis and graphic display of big data;

the high-speed signal acquisition and processing unit is mainly used for acquiring externally input intermediate-frequency signals and transmitting data to the main control unit through a PCIe interface;

the down-conversion unit is mainly used for converting the radio-frequency signals into intermediate-frequency signals and sending the intermediate-frequency signals to the high-speed signal acquisition and processing unit;

the local oscillation unit is mainly used for generating local oscillation signals of a required frequency band and providing a frequency conversion local oscillation interface for the down-conversion unit;

the high-speed data storage unit is mainly used for high-speed recording of data files.

The signal transmitting module is realized by adopting a VPX architecture and a modular design and comprises a basic hardware unit, a main control unit, a clock interface unit, a signal generating unit, a high-speed storage unit and a signal conditioning and monitoring unit; wherein the content of the first and second substances,

the basic hardware unit comprises a case, a back plate and a power supply, is the basis for the operation of the whole case, and provides power supply and data transmission channels for all the functional units;

the main control unit is mainly used for controlling the whole signal transmitting module, providing a signal transmitter hardware control software running platform, and interconnecting with the clock interface unit through PCIe (peripheral component interconnect express) to complete the control and communication with other hardware at the bottom layer;

the clock interface unit is mainly used for controlling and transmitting data between the main control unit and the signal generating unit and providing reference clocks for other functional units in the case;

the signal generation unit is mainly used for generating analog signals or reading data from the high-speed storage unit through an SRIO 8x interface to generate signals;

the high-speed storage unit is mainly used for storing signal parameters and signal data and providing the signal data in a playback mode;

and the signal conditioning and monitoring unit is mainly used for filtering and amplifying the signals output by the signal generating unit and coupling the output signals to provide an observation channel.

As shown in fig. 2 and 3, a dynamic background signal generation method, which is generated by the dynamic background signal generation system, includes the following steps:

s1, detecting and sensing the target signal, and acquiring carrier frequency, modulation type and bandwidth information of the target signal; the concrete implementation is as follows:

s1.1, carrier frequency estimation of target signal

Estimating the frequency by adopting a zero-crossing detection method of a time domain; the zero-crossing detection method is to perform zero-crossing detection on the input signal sequence x (n), if x (n)_i) And x (n)_i+1) have different signs, it can be determined that the time period (n) is the same_i/F_s,(n_i+1)/F_s) There is a zero point therebetween, wherein F_sRepresenting the sampling rate, the position of the zero point being calculated using a linear interpolation formula

Forming a zero-crossing sequence { α (i) } from the time instants of the detected zero points, where i is 1,2, …, M, where M is the number of detected zero-crossing points; defining the sequence of first order differences of { alpha (i) } as a sequence of zero-crossing spacings { beta (i) }, i.e.

β(i)＝α(i+1)-α(i),i＝1,2,…,M-1

For a single frequency signal in noise, the distance between two zeros is

ε (i) is a random number obeying a zero-mean distribution, F_cRepresenting the signal frequency. From E [ epsilon (i)]Get 0 ═ toThus, the frequency F is estimated from the mean value of β (i)_cI.e. by

S1.2, identification of modulation type of target signal

S1.21, firstly, carrying out down-conversion processing on a signal by using the carrier frequency estimation result in the step S1.1;

s1.22, selecting modulation signal characteristic parameters, and identifying a digital characteristic set consisting of Amplitude Modulation (AM), Frequency Modulation (FM), amplitude shift keying (ASK, 4ASK), frequency shift keying (2FSK, 4FSK) and Binary Phase Shift Keying (BPSK) by adopting a method of judging numbers; the classification characteristics comprise a maximum spectral density value of zero-center normalized instantaneous amplitude, a standard deviation of zero-center nonlinear instantaneous phase, a spectral symmetry degree, a standard deviation of zero-center nonlinear instantaneous phase absolute value, a standard deviation of zero-center normalized instantaneous amplitude absolute value and a standard deviation of zero-center normalized instantaneous frequency absolute value; the method specifically comprises the following steps:

(1) zero center normalized instantaneous amplitude of the maximum gamma of the spectral density_max

In the formula, N_sCounting the number of sampling points; a is_cn(i) The sequence after taking the zero center for the normalized instantaneous amplitude is calculated by

a_cn(k)＝a_n(k)-1

Wherein a (k) is a sequence of sampled signals, m_aIs the average value of the signal sequence, a_n(k) Is a signal instantaneous amplitude sequence;

(2) zero center nonlinear instantaneous phase standard deviation σ_dp

In the formula, a_tA strong signal decision threshold, c is the number of strong signals in the sample sequence,is a non-linear instantaneous phase sequence, sigma, subjected to zero-center normalization_dpRepresenting the degree of change of the nonlinear phase, and is used for identifying and classifying AM and DSB signals;

(3) degree of spectral symmetry P

In the formula, x (k) is an FFT sequence obtained after fourier transform of the signal x (k), and N is a corresponding sequence number of the carrier frequency point in the FFT sequence;

(4) zero center non-linear instantaneous phase absolute value standard deviation sigma_ap

In the formula, a_TA threshold for strong signal determination, c the number of strong signals in the sample sequence,is a nonlinear instantaneous phase sequence normalized by the zero-crossing center, which is used for identifying BPSK signals from { BPSK, QPSK, 2FSK, 4FSK };

(5) zero center normalized instantaneous amplitude absolute value standard deviation sigma_aa

In the formula, σ_aaMainly to distinguish between 2ASK and 4ASK signals, and_apin the same principle, the 2ASK signal amplitude is only two, and the zero center normalization instantaneous amplitude absolute value standard deviation sigma thereof_aa0 is approximately distributed; 4ASK signal amplitudes four, corresponding to parameter sigma_aa＞0；

(6) Zero center normalized instantaneous frequency absolute value standard deviation sigma_af

In the formula (f)_N(k) Is a zero-center normalized instantaneous frequency sequence, σ_afMainly used for distinguishing 2FSK and 4FSK signals;

f_N(k) the calculation is performed by the following formula in the prior art

f_c(k)＝f(k)-m_f

f_N(k)＝f_c(k)/r_b；

S1.23, identifying signals with different modulation patterns by adopting a modulation identification method based on signal instantaneous characteristics; the classifier in the modulation recognition system adopts a decision tree classifier;

s2, formulating a background signal generation rule, and generating parameter configuration information required by a signal generation module according to a target signal reconnaissance sensing result; the specific operation is as follows:

s2.1, making a background signal generation rule

The signal generation rules are the basis for the dynamic background signal generation system signal generation scheme. And determining the parameter configuration of the transmitting signal by the information processing computer according to the signal generation rule. The background signal generation rule refers to GJB6520-2008 battlefield electromagnetic environment classification and classification method or user-defined and domain expert knowledge, and specifies frequency difference between the subsequently generated background signal and the target signal, instantaneous signal number, instantaneous amplitude change condition and the like, and also reflects the complexity level of the electromagnetic environment signal.

According to a GJB6520-2008 battlefield electromagnetic environment classification and classification method, according to the electromagnetic environment signal complexity level, battlefield electromagnetic environments are classified into a mild complex electromagnetic environment (I-level electromagnetic environment), a moderate complex electromagnetic environment (II-level electromagnetic environment) and a severe complex electromagnetic environment (III-level electromagnetic environment) in three levels. In actual operation, according to the promotion of experiments, electromagnetic environments with different complexity levels are set and constructed by comprehensively setting four elements of key frequency band bandwidth, signal number, signal strength and signal style, and a signal generation rule design flow is shown in fig. 4.

(1) The key frequency band bandwidth complexity setting principle is as follows: acquiring the frequency range and the occurrence probability information of a target signal according to the target signal reconnaissance sensing result, and determining a target signal key frequency band;

L_i＝(f_high-f_low)×x％

in the formula, L_iFor simulated focal region bandwidth, f_highAt the high end of the working frequency band or at the high end of the frequency hopping bandwidth, f_lowIs the low band of the working frequency band or the low end of the frequency hopping bandwidth, x% is set according to the scale of the electromagnetic environment;

under the requirements of different complexity levels, setting the proportion x% of the bandwidth generated by the background signal to the bandwidth of the key frequency band as follows: 5% (class i electromagnetic environment, i.e. mild complex electromagnetic environment), 15% (class II electromagnetic environment, i.e. medium complex electromagnetic environment), 30% (class III electromagnetic environment, i.e. severe complex electromagnetic environment);

(2) signal number complexity setting principle: setting different signal quantities according to the key frequency band bandwidth and the channel bandwidth of the tested object and the complexity of different levels;

in the formula, w_iA channel bandwidth for the communication device;

(3) signal strength complexity setting principle: the fluctuation range of the background signal strength reflects the interference degree of the background signal on the tested equipment in an energy domain, and the signal strength complexity setting method comprises the following steps:

E_n＝P+P*x_P_n

wherein P is the target signal strength, E_nTaking the background signal intensity as x _ P _ n, and taking the complex electromagnetic environment intensity factors of different levels as x _ P _ n;

under the I-level complex electromagnetic environment, the value range of x _ P _1 is (-0.2, -0.1);

under the II-level complex electromagnetic environment, the value range of x _ P _2 is (0, 0.1);

in a III-level complex electromagnetic environment, the value range of x _ P _3 is (0.1, 0.2);

x _ P _1, x _ P _2 and x _ P _3 are evenly distributed random numbers in a value range and are refreshed once every 100 ms;

(4) signal pattern complexity setting principle: the setting of the signal pattern complexity is determined based on various electronic equipment patterns faced by the tested equipment, the characteristics of presenting diversity along with the increase of the complexity are reflected, the signal pattern settings of I-level, II-level and III-level complex electromagnetic environments are gradually complicated and the number of the signal patterns is gradually increased according to the test requirements, for example, the number of the signal patterns under the I-level, II-level and III-level complex electromagnetic environments is respectively set to be 5, 8 and 10;

s2.2, making a background signal generation rule

Judging whether parameters such as carrier frequency, modulation type and the like in the reconnaissance sensing result are changed, and if so, regenerating parameter configuration information according to the background signal generation rule in the step S2.1; if no change exists, the previous parameter configuration information is kept, and only the signal intensity is refreshed;

s3, generating signal according to parameter configuration information

The background signal generation mode comprises a signal playback mode and an autonomous generation mode; wherein the content of the first and second substances,

and (3) standardizing a sample set signal playback mode: after receiving and analyzing the parameter configuration information sent by the information processing and calculating module, the main control unit of the signal transmitting module retrieves baseband signal sample library data from a database according to the parameters and stores the baseband signal sample library data in a high-speed storage unit, and when playback output is needed, the main control unit reads the data from the high-speed storage unit to DAC (digital-to-analog converter) for playback output and simultaneously adjusts the frequency and the power of the signal;

an autonomous generation mode: after receiving and analyzing the parameter configuration information sent by the information processing and calculating module, the main control unit of the signal transmitting module adjusts the parameters of the generated signals in the local signal transmitting module according to the parameters, and then sends the parameters to the signal generating unit to realize the generation of the signals;

the reconnaissance sensing result is autonomously controlled by an internal program in the aspects of radio frequency change, amplitude control and playback file selection, and the generated signal has better real-time dynamic property.

The above description is only a preferred embodiment of the present invention, and not intended to limit the present invention, and all equivalent changes and modifications made within the scope of the claims of the present invention should fall within the protection scope of the present invention.