CN115622575A

CN115622575A - Fuze simulator implementation method based on software radio

Info

Publication number: CN115622575A
Application number: CN202211219912.9A
Authority: CN
Inventors: 张淑宁; 刘月鑫
Original assignee: Nanjing University of Science and Technology
Current assignee: Nanjing University of Science and Technology
Priority date: 2022-10-07
Filing date: 2022-10-07
Publication date: 2023-01-17

Abstract

The invention discloses a realization method of a fuze simulator based on software Radio, which takes an X310 series of USRP as a general software Radio hardware platform, GNU Radio as a software platform, realizes hardware drive through UHD and realizes a user-defined signal processing function by establishing an OOT module; the functions of fuze transmitting signal generation and subsequent digital signal processing are realized in GNU Radio, and X310 realizes digital up/down conversion and ADC/DAC functions; the fuze simulator realized by the method can generate the transmitting signals with different systems and different parameters and realize the signal processing function simulation of the fuzes with different systems. The invention is based on software radio, takes hardware as a basic platform of radio fuze, realizes as many fuze functions as possible through software, and solves the integration and intercommunication capacity of the radio fuze of different frequency bands under different systems.

Description

Fuse simulator implementation method based on software radio

Technical Field

The invention relates to a software radio technology, in particular to a fuze simulator implementation method based on software radio.

Background

Conventional radio communication devices are various in kind, poor in interchangeability and unchanged in production management.

Software radio technology is widely applied to the field of radio communication, and is characterized in that traditional hardware radio communication equipment is only used as a basic platform of radio communication, and a plurality of communication functions are realized by software, so that the software radio technology has strong flexibility and strong openness.

Disclosure of Invention

The invention aims to provide a method for realizing a fuze simulator based on software radio, which aims to overcome the problem of the realization of the fuze simulator in the existing software radio architecture.

The technical solution for realizing the purpose of the invention is as follows: a fuze simulator implementation method based on software radio comprises the following steps:

and (3) setting up a GNU Radio and USRP software Radio platform: GNU Radio is matched with USRP to realize connection between a host and a Radio frequency space, an IP address of the host is modified, uhd _ find _ devices is input into a terminal, and if the display equipment information shows that the connection is successful, the software Radio platform is built;

the signal processing module creates: creating a new module through a gr _ model newmod [ modulename ], gr _ model add [ blockname ] instruction; modifying/include/modulename/blockname.h to create a modulename class of the newly-built module; modifying/lib/blockname _ impl.h to realize the object and member function declaration of the derivative class of the new modeling block class; c, realizing member function definition and signal processing functions by modifying/lib/blockname _ impl.cc; the visualization of the modification/grc/blockname. Building a built folder, inputting a cmake./and a make instruction at a terminal under the built folder to finish compiling, and finishing installing a sudo make install;

generating fuze simulator transmission data: establishing a transmitting signal data generating module, wherein a fuse simulator is used for controlling the type of a transmitting signal, including linear frequency modulation, sinusoidal frequency modulation, pseudo code phase modulation, doppler pulse trains and various composite systems, and setting parameters to generate various waveform data; simultaneously selecting whether to simulate the echo amplification effect, and setting the amplification order and the amplification rate; data generated by the host is transmitted to an X310, digital up-conversion is realized through an FPGA, DAC processing is realized through a radio frequency transmitting sub-board, the data is transmitted through an antenna, after being reflected by a target, echo signals received by a receiving antenna are processed through an ADC (analog-to-digital converter) of a radio frequency receiving sub-board, transmitted to the FPGA for digital down-conversion processing, and then transmitted to the host for further signal processing;

echo signal processing: aiming at signal processing flows of fuzes of different systems, an FFT (fast Fourier transform) module is used for measuring and calculating the difference frequency of a linear frequency modulation system; the related processing module performs related processing on the pseudo code system and the pulse system; an envelope extraction module extracts each subharmonic envelope of a difference frequency signal of a multi-sine frequency modulation system to realize spacing; the undersampling module performs time domain undersampling processing to extract echo Doppler frequency; the data shunting module realizes shunting processing on data, divides a group of data streams into a plurality of data streams and realizes distance and speed measurement of a multi-parameter system; the measuring and calculating module obtains distance information through difference frequency, and obtains speed information through Doppler frequency; the echo amplification rate measurement module realizes the functions of envelope extraction and amplification measurement of echo signals; and the measuring and calculating result is displayed on the terminal through a message transmission mechanism.

Compared with the prior art, the invention has the following beneficial effects: the GNU Radio and USRP software Radio platform is a flexible and efficient software Radio platform which takes the GNU Radio as a software architecture and the USRP as a hardware platform and can run in a plurality of operating systems. The invention is based on software radio, takes hardware as a basic platform of radio fuze, realizes as many fuze functions as possible through software, and solves the integration and intercommunication capacity of the radio fuze of different frequency bands under different systems. With greater flexibility, new software modules can be added to add new communication functions.

Drawings

Fig. 1 is a block diagram of a fuze simulator based on software radio.

Fig. 2 is a diagram of a USRP initialization terminal.

FIG. 3 is a GNU Radio self-building module file directory.

Fig. 4 is a flow diagram of a fuze simulator transmit signal.

Fig. 5 is a waveform diagram of a fuse simulator transmitting signal.

Fig. 6 is a schematic diagram of a measured result, a signal processing waveform diagram and a start signal of the fuze simulator.

Detailed Description

The invention provides a method for realizing a fuze simulator based on software radio, which is based on software radio, takes hardware as a basic platform of radio fuze, realizes the fuze functions as much as possible through software, and solves the integration and intercommunication capacity of the radio fuze in different frequency bands under different systems. The invention takes an X310 series of USRP (Universal Software Radio Peripheral) as a general Software Radio Hardware platform, takes GNU Radio as a Software platform, realizes Hardware drive through UHD (Universal Hardware Driver), and realizes a self-defined signal processing function through creating an OOT (Out of Tree Module) Module. The fuze transmit signal generation and subsequent digital signal processing functions are implemented in GNU Radio, and X310 implements digital up/down conversion and ADC/DAC functions.

The method for realizing the radio fuze simulator with various systems based on software radio comprises the following specific steps:

step 1, a GNU Radio and USRP software Radio platform is set up. The software platform is based on the Ubuntu18.04 system, and installs GNU Radio, UHD and a large number of dependent libraries. GNU Radio is matched with USRP to realize the connection between a computer and a Radio frequency space, a host is connected with the USRP through a gigabit network cable, the IP address of the host is modified, uhd _ find _ devices are input into a terminal, and if the display equipment information shows that the connection is successful, the software Radio platform is built.

And 2, establishing a signal processing module. The signal processing module in the GNU Radio cannot meet the requirement of fuze on high-performance signal processing, and a high-performance signal processing module needs to be created. A new module is created by a gr _ model newmod [ modulename ], gr _ model add [ blockname ] instruction. Modifying/include/modulename/blockname.h to complete the declaration of the new modeling block class; modifying/lib/blockname _ impl.h to realize the object and member function declaration of the derived class of the new modeling block class; c, realizing function definition and signal processing functions by modifying/lib/blockname _ impl.cc; xml file implementation module visualization under GNU Radio. And newly building a built folder, inputting a cmake./and a make instruction at a terminal under the built folder to finish compiling, and finishing installing a sudo make install.

Step 3, generating fuze simulator transmitting data: and a transmitting signal data generation module is created, the maximum processing bandwidth of X310 is 200MHz, the maximum frequency of a signal generated by the host cannot exceed 100MHz, the fuze simulator can control the type of the transmitting signal, including linear frequency modulation, sinusoidal frequency modulation, pseudo code phase modulation, doppler pulse trains and various composite systems, and any reasonable parameter can be set to generate various waveform data. Meanwhile, whether the echo amplification effect is simulated or not can be selected, and the amplification order and the amplification rate are set to simulate different echo amplification effects. Data generated by the host computer is transmitted to the X310, digital up-conversion is realized through the FPGA, DAC processing is realized through the radio frequency transmitting sub-board, the data is transmitted through the antenna, after reflection of the target, echo signals received by the receiving antenna are processed through the radio frequency receiving sub-board ADC, transmitted to the FPGA for digital down-conversion processing, and then transmitted to the host computer for further signal processing.

And 4, processing a signal by the fuze simulator: the signal processing function and the measurement and calculation of the fuze simulator based on the software radio are completed in a host. Aiming at signal processing flows of fuses of different systems, an FFT module is designed to measure and calculate difference frequency of a linear frequency modulation system; the related processing module carries out related processing on the pseudo code system and the pulse system; an envelope extraction module extracts each subharmonic envelope of a difference frequency signal of a multi-sine frequency modulation system to realize distance; the undersampling module performs time domain undersampling processing to extract echo Doppler frequency; the data shunt module realizes shunt processing of data, divides a group of data into multiple paths of data according to a self-defined rule, and realizes distance and speed measurement of a multi-parameter system. The measuring and calculating module obtains distance information through difference frequency, and obtains speed information through Doppler frequency; the echo amplification rate measuring and calculating module realizes the functions of envelope extraction and amplification measurement and calculation of echo signals. And the measuring and calculating result is displayed on the terminal through a message transmission mechanism. The waveform of signal processing at each stage can be observed by an oscilloscope module, and the oscilloscope module comprises a time domain graph, a frequency domain graph, a waterfall graph and the like.

Further, for the transmission signal data generation module, the sampling rate is set to samp _ rate (not more than 200 MHz). When a linear frequency modulation system is transmitted, the number of upper frequency sweeping points and the number of lower frequency sweeping points are respectively samp _ up and samp _ down, samp _ down is 0 to represent sawtooth wave frequency modulation, samp _ up and samp _ down are equal to represent triangular wave frequency modulation, the modulation period is samp _ up/samp _ down, the frequency modulation bandwidth speed _ freq is generally set to be samp _ rate to obtain the minimum distance resolution, the signal period is ped, and linear frequency modulation transmitting signals with self-defined parameters can be generated based on the parameters. The multi-sine frequency modulation and the linear frequency modulation are similar in principle, and the difference is that the frequency of a linear frequency modulation transmitting signal is changed linearly, the multi-parameter frequency modulation is changed according to sine modulation, the number of sampling points in a single period is set to be sampsin, and the period is sampsin/samprate. The generation principle of the pseudo code signal is the same as that of the pulse train signal, vector type parameters send _ samp and wait _ samp are set to respectively represent the number of points corresponding to data with the amplitude of 1 and the number of points corresponding to the amplitude of-1, and any pseudo code signal and any pulse train signal can be customized by setting the values of send _ samp and wait _ samp. The module for generating frequency modulation signals and the module for generating pseudo codes and pulses can realize the composite system fuze through a multiplier.

Furthermore, various system fuze transmitting signals generated by the host computer are converted into analog radio frequency signals through USRP and transmitted through the antenna, the process is controlled by the UHD:: USRP Sink module, the radio frequency signals of the receiving end can be converted into low frequency signals through UHD:: USRP Source control and transmitted to the host computer for processing, and because X310 has random delay and the influence of the length of a cable connected with the antenna, distance correction and random delay measurement and calculation are needed before each measurement and calculation to reduce the distance measurement error. X310 is double-transmitting and double-receiving, one transmitting port is directly connected with a receiving port through a feeder line, a transmitting signal and an echo signal are measured and delayed through a correlator at a software end, delay information is transmitted to a USRP Source module, and therefore the random delay amount is reduced after the echo signal is received by the other receiving port, and the distance measuring and calculating precision is improved. Because the actual test target speed cannot be too high, and simultaneously, in order to simulate a real target scene, the Doppler effect brought by the target speed is realized at a software end, the echo signal is converted into a frequency domain through FFT (fast Fourier transform), a theoretical Doppler frequency is added, then IFFT (inverse fast Fourier transform) is carried out to convert the frequency domain into a time domain, and the echo signal after Doppler compensation at the software end can simulate the echo signal of a real moving target, namely the Doppler effect of the moving target can be simulated. The FFT module is implemented based on the FFTW3 library and is used for measuring and calculating the difference frequency and the Doppler frequency. The correlator implementation is based on volk (Vector-manipulated Library of Kernels), and rapidly implements dot product operation of two input streams, so as to obtain the time delay between the local signal and the echo signal. The envelope extraction module is based on the envelope detection principle, the extracted envelope is divided into a plurality of sections, the average value of the amplitude of each section is measured and calculated respectively, and then the amplification rate is obtained.

Furthermore, after different signal processing models are established for fuzes of different systems, the obtained measuring and calculating results need to be printed at a terminal. Polymorphic Types (Polymorphic Types) are used as data carriers for block-to-block transfers, often as labels for data streams and message transfers, and Polymorphic type data may be boolean, integer, complex, dictionary, etc. The data stream transmission between the blocks can only be from the upstream block to the downstream block, and can not be in the reverse direction, but the message transmission between the blocks has no such limitation, the message transmission can be carried out between any two blocks, and the measured and calculated result can be conveniently printed out on the terminal through a message transmission mechanism. The invention realizes the fuze simulator based on software radio for the first time.

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

Examples

A method for realizing a radio fuze simulator with multiple systems based on software radio, as shown in figure 1, comprises the following steps:

step 1, a GNU Radio and USRP software Radio platform is set up. GNU Radio and USRP structure diagrams are shown in FIG. 2, the IP address of the host is modified, the USB cable is used for connecting the host and the USRP, and the terminal displays the equipment information after uhd _ find _ devices are input, as shown in FIG. 2.

And 2, creating a signal processing module through gr _ model, modifying/include h files and/lib files to realize a specific signal processing function, and modifying/grc files to realize module visualization. And creating a build folder, inputting a cmake./and a make instruction at a terminal under the build folder to finish compiling, and finishing installing a sudo make install. The custom module file directory is shown in figure 3.

And 3, establishing fuze transmitting signal models of different systems and establishing a flow graph. For the transmission signal data generation block, the sampling rate is set to sampjrate (not more than 200 MHz). When a linear frequency modulation system is transmitted, the number of upper frequency sweeping points and the number of lower frequency sweeping points are respectively samp _ up and samp _ down, samp _ down is 0 to represent sawtooth wave frequency modulation, samp _ up and samp _ down are equal to represent triangular wave frequency modulation, the modulation period is samp _ up/samp _ down, the frequency modulation bandwidth is samp _ freq, the period is ped, and a linear frequency modulation transmission signal with self-defined parameters can be generated based on the parameters. The multi-sine frequency modulation and the linear frequency modulation are similar in principle, and the difference is that the frequency of a linear frequency modulation transmitting signal is changed linearly, the multi-parameter frequency modulation is changed according to sine modulation, the number of sampling points in a single period is set to be sampsin, and the period is sampsin/samprate. The generation principle of the pseudo code signal is the same as that of the pulse train signal, the vector parameters send _ samp and wait _ samp are set to respectively represent the number of points corresponding to data with the amplitude of 1 and the number of points corresponding to the amplitude of-1, and any pseudo code signal and any pulse train signal can be customized by setting the values of send _ samp and wait _ samp. The module for generating frequency modulation signals and the module for generating pseudo codes and pulses can realize the composite system fuze through a multiplier.

The flow chart of the signal generated by the transmitting end of the fuze simulator is shown in fig. 4, and the waveform of the signal transmitted by the fuze simulator is shown in fig. 5.

And 4, controlling the transmission and the reception of the radio frequency signal of the fuze simulator, and performing software-end signal processing on the echo signal after down-conversion. The method comprises the steps that various system fuze transmitting signals generated by a host are converted into analog Radio frequency signals through USRP and transmitted through an antenna, the process is controlled by a UHD, USRP Sink module, GNU Radio creates a signal for us without modification, the Radio frequency signals at a receiving end can be converted into low-frequency signals through UHD, USRP Source control and the low-frequency signals are processed by the host, and distance correction and random delay measurement need to be carried out before each measurement and calculation due to the fact that X310 has random delay and the length of a cable connected with the antenna. X310 is double-transmitting and double-receiving, one transmitting port is directly connected with a receiving port through a feeder line, a transmitting signal and an echo signal are measured and delayed through a correlator at a software end, delay information is transmitted to a USRP Source module, and therefore the random delay amount is reduced after the echo signal is received by the other receiving port, and the distance measuring and calculating precision is improved. Because the actual test target speed cannot be too high, and simultaneously, in order to simulate a real target scene, the Doppler effect brought by the target speed is realized at a software end, the echo signal is converted into a frequency domain through FFT (fast Fourier transform), a theoretical Doppler frequency is added, then IFFT (inverse fast Fourier transform) is carried out to convert the frequency domain into a time domain, and the echo signal after Doppler compensation at the software end can simulate the echo signal of a real moving target, namely the Doppler effect of the moving target can be simulated. The FFT module is implemented based on the FFTW3 library and is used for measuring and calculating the difference frequency and the Doppler frequency. The correlator implementation is based on bulk (Vector-manipulated Library of Kernels), and fast implements dot product operation of two input streams, thereby obtaining the time delay between the local signal and the echo signal. The envelope extraction module is based on the envelope detection principle, the extracted envelope is divided into a plurality of sections, the average value of the amplitude of each section is measured and calculated respectively, and then the amplification rate is obtained.

To verify the effectiveness of the present invention, the following actual scenario experiments were performed. The system parameters are: the sampling rate is 200MHz, the central frequency is 3.4GHz, the moving distance range of the target plate is 0-20 m, and the speed is 200m/s. Each system signal is continuously transmitted and intermittently received, the number of times of measurement and calculation in unit time can be set, if the measurement and calculation are carried out, the terminal continuously transmits 'O' to indicate that the host cannot synchronously receive data from the USRP, and continuously transmits 'U' to indicate that the computer cannot provide a large amount of data to the USRP, so that the problem can be solved by properly reducing the signal period and reducing the data amount. The measurement results of each system, the waveform diagram of signal processing and the start signal are shown in fig. 6. The measuring and calculating result is consistent with the actual result and accords with the design requirement.

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

Claims

1. A fuze simulator implementation method based on software radio is characterized by comprising the following steps:

and (3) establishing a GNU Radio and USRP software Radio platform: GNU Radio is matched with USRP to realize connection between a host and a Radio frequency space, an IP address of the host is modified, uhd _ find _ devices is input into a terminal, and if the display equipment information shows that the connection is successful, the software Radio platform is built;

the signal processing module creates: creating a new module through a gr _ model newmod [ modulename ], gr _ model add [ blockname ] instruction; modifying/include/modulame/blockname.h to create a modulame class of the newly-built module; modifying/lib/blockname _ impl.h to realize the object and member function declaration of the derived class of the new modeling block class; c, realizing member function definition and signal processing functions by modifying/lib/blockname _ impl.cc; the visualization of the modification/grc/blockname. Building a build folder, inputting a cmake./and a make instruction at a terminal under the build folder to finish compiling, and finishing installing a sudo make install;

generating fuze simulator transmission data: creating a transmitting signal data generating module, wherein a fuse simulator is used for controlling the types of transmitting signals, including linear frequency modulation, sinusoidal frequency modulation, pseudo code phase modulation, doppler pulse trains and various composite systems, and setting parameters to generate various waveform data; simultaneously selecting whether to simulate the echo amplification effect, and setting the amplification order and the amplification rate; data generated by the host is transmitted to an X310, digital up-conversion is realized through an FPGA, DAC processing is realized through a radio frequency transmitting sub-board, the data is transmitted through an antenna, after being reflected by a target, echo signals received by a receiving antenna are processed through an ADC (analog-to-digital converter) of a radio frequency receiving sub-board, transmitted to the FPGA for digital down-conversion processing, and then transmitted to the host for further signal processing;

echo signal processing: aiming at signal processing flows of fuses of different systems, an FFT module is used for measuring and calculating difference frequency of a linear frequency modulation system; the related processing module performs related processing on the pseudo code system and the pulse system; an envelope extraction module extracts each subharmonic envelope of a difference frequency signal of a multi-sine frequency modulation system to realize distance; the undersampling module performs time domain undersampling processing to extract echo Doppler frequency; the data shunt module is used for achieving shunt processing of data, dividing a group of data streams into a plurality of data streams and achieving distance and speed measurement of a multi-parameter system; the measuring and calculating module obtains distance information through the difference frequency, and the Doppler frequency obtains speed information; the echo amplification rate measurement module realizes the functions of envelope extraction and amplification measurement of echo signals; and the measuring and calculating result is displayed on the terminal through a message transmission mechanism.

2. The method as claimed in claim 1, wherein the software platform is based on ubuntu18.04, and GNU Radio, UHD and dependency library are installed.

3. The software radio-based fuze simulator implementation method according to claim 1, characterized in that, for the transmission signal data generation module, a sampling rate is set to sampjrate; when a linear frequency modulation system is transmitted, the number of upper frequency sweeping points and the number of lower frequency sweeping points are respectively designated samp _ up and samp _ down, the samp _ down is 0 to indicate sawtooth wave frequency modulation, the samp _ up and samp _ down are equal to indicate triangular wave frequency modulation, the modulation period is samp _ up/samp _ down, the frequency modulation bandwidth speedup _ freq is set as samp _ rate to obtain the minimum distance resolution, the signal period is ped, and linear frequency modulation transmitting signals with self-defined parameters can be generated based on the parameters; the multi-sine frequency modulation changes according to sine modulation, the number of sampling points in a single period is set to be samp _ sin, and the period is samp _ sin/samp _ rate; the generation principle of the pseudo code signal is the same as that of the pulse train signal, the sender type parameters send _ samp and wait _ samp are set to respectively represent the number of points corresponding to data with the amplitude of 1 and the number of points corresponding to the amplitude of-1, and any pseudo code signal and any pulse train signal are customized by setting the values of send _ samp and wait _ samp; and the module for generating the frequency modulation signal and the module for generating the pseudo code and the pulse realize the composite system fuze through a multiplier.

4. The software radio-based fuze simulator implementation method of claim 3, wherein the sampling rate samp _ rate is not greater than 200MHz.

5. The software radio-based fuze simulator implementation method of claim 1, wherein the X310 maximum processing bandwidth is 200MHz, and the maximum frequency of the signal generated by the host does not exceed 100MHz.

6. The software defined radio-based fuze simulator implementation method of claim 1, wherein the waveforms of the signal processing of each stage are observed by an oscilloscope module, and the oscilloscope module displays a time domain graph, a frequency domain graph and a waterfall graph.

7. The software radio-based fuze simulator implementation method according to claim 1, wherein the fuze transmission signals of various systems generated by the host are converted into analog radio frequency signals through USRP and transmitted through an antenna; x310 is double-transmitting and double-receiving, one transmitting port is directly connected with a receiving port through a feeder line, a transmitting signal and an echo signal are measured and delayed through a correlator at a software end, delay information is transmitted to a USRP Source module, and the random delay quantity is subtracted from the other receiving port after the echo signal is received; the echo signal is transformed to a frequency domain through FFT (fast Fourier transform), a theoretical Doppler frequency is added, then IFFT is transformed to a time domain, and the echo signal subjected to Doppler compensation at a software end simulates the echo signal of a real moving target, so that the Doppler effect of the moving target can be simulated; the FFT module is realized based on an FFTW3 library and is used for measuring and calculating difference frequency and Doppler frequency; the correlator realizes the dot product operation of two input streams based on the volk, thereby obtaining the time delay between the local signal and the echo signal; the envelope extraction module is based on the envelope detection principle, the extracted envelope is divided into a plurality of sections, the average value of the amplitude of each section is measured and calculated respectively, and then the amplification rate is obtained.

8. The method for realizing the software radio-based fuze simulator according to claim 7, wherein the fuze transmitting signals of various systems generated by the host are converted into analog radio frequency signals through USRP and transmitted through an antenna, the process is controlled by a UHD (ultra high performance) USRP Sink module, and the radio frequency signals at the receiving end are converted into low frequency signals through UHD USRP Source control and transmitted to the host for processing.

9. The method as claimed in claim 7, wherein after different signal processing models are built for fuzes of different systems, the obtained measurement results are printed at the terminal, a message transmission mechanism is adopted, a message transmission port is defined in the module, and messages to be transmitted are defined as polymorphic types.

10. The software radio-based fuze simulator implementation method of claim 9, wherein the messages to be transmitted include distance, speed, echo amplification rate.