CN114325606A - Multi-system agile radar radio frequency echo signal simulation method - Google Patents

Abstract

The invention provides a multi-system agile radar radio frequency echo signal simulation method, which can realize the simulation of the multi-system radar echo signal by using less software and hardware resources, and greatly reduces the time of the radar echo signal simulation system. cost and volume. In addition, the present invention can utilize the agile switching of the host computer interface to complete the simulation of radar echo signals of various systems in the same continuous echo acquisition test, and the operation has strong flexibility. At the same time, the present invention adopts the ping-pong operation to realize the radar echo signal generation method. When the FPGA end receives a new set of PRT echo data, the echo data is placed on the RAM address where the newly output set of PRT echo data is located, so as to The original PRT echo data is updated in real time, and the parameters such as the starting distance of the PRT and the number of sampling points of the data are updated to realize the ping-pong operation, which can save the FPGA logic resources and improve the time utilization rate.

Description

A multi-system agile radar RF echo signal simulation method

technical field

The invention belongs to the technical field of radar digital signal processing, and in particular relates to a multi-system agile radar radio frequency echo signal simulation method.

Background technique

At present, the function and performance test of the software and hardware of the radar seeker often relies on the field experiment test, and the field experiment test has high requirements on the test conditions, including the target target and the site environment, but it is not always ideal in actual situations. This is a big challenge for the function and performance test verification of the radar seeker software and hardware.

The radar intermediate frequency echo simulation system can realize the target feature simulation of the field experiment scene with the help of software and hardware according to the radar echo waveform design method. Must rely on field test problems. At present, the design methods of the more mature radar echo simulation system are roughly divided into the following two categories:

1) A pure software radar echo simulation system based on computer development and design. This design method uses computer to generate target echo information and interference information. However, due to the limitations of the computer itself, the speed of data generation is slow, and real-time target echo simulation and interference signal simulation cannot be realized.

2) The other is to design a radar echo simulation system based on a hardware signal processing board. This design method will be limited by the memory capacity of the hardware signal processing board, resulting in few types of radar echoes and application scenarios. more singular.

SUMMARY OF THE INVENTION

In order to solve the above problems existing in the prior art, the present invention provides a multi-system agile radar radio frequency echo signal simulation method. The technical problem to be solved by the present invention is realized by the following technical solutions:

The invention provides a multi-system agile radar radio frequency echo signal simulation method, which is applied to a communication server and a radar signal processing board, wherein the communication server is communicatively connected to the radar signal processing board, and the radar signal processing The board is composed of a DSP, an FPGA chip, a radio frequency module, a DA module and a peripheral circuit; the simulation method includes:

Establish the host computer software for sending radar-related parameters to the radar signal processing board on the communication server;

Wherein, the host computer software includes a software interface, the software interface includes: a radar-related parameter editing box and function buttons, and the radar-related parameter editing box includes an echo selection X, an echo quantization amplitude Amp, a CPI internal The number of PRTs kk, the number of time-width sampling points nTp within a pulse width _Tp , the target distance range R_range, the echo starting distance R, the target speed V _r , the echo pulse repetition period PRT, the carrier frequency sequence f _m , the echo pulse Beam pitch angle fai0 and the input box of echo beam azimuth angle theta0 parameter; Described function button includes generate echo data button, open TCP service button, start sending data button, reset button and attenuation enable button;

In the software interface of the host computer software, the echo mode is switched agilely through the echo mode selection button, and the radar-related parameters are generated in different echo modes through the edit box. When receiving the operation instruction of the button to generate echo data , generating original echo pulse data according to the radar-related parameters, and forming a data frame with the radar-related parameters and the original echo pulse data;

Select the button to start sending data, and send the data frame to the DSP in the radar signal processing board;

The DSP determines target information according to the radar-related parameters of the data frame, continuously constructs a PRT echo pulse signal model based on the target information and the original echo pulse data, and sends the Nth PRT echo pulse signal model to the FPGA , count the total number of PRT echo pulse signal models that have been sent to the FPGA; according to the total number and radar-related parameters, calculate the starting distance of N+1 PRT echo pulses and the number of data sampling points, and construct the N+1th PRT echo pulse Signal model, when receiving the request to send command sent by FPGA, send the N+1th PRT echo pulse signal model to FPGA;

Among them, N is a positive integer starting from 1;

The FPGA stores the Nth PRT echo pulse signal model, and outputs the Nth PRT echo pulse signal model to the DA module according to the echo simulation output instruction generated by itself;

The DA module generates a simulated radar intermediate frequency echo signal according to the Nth PRT echo pulse signal model, and outputs the radar intermediate frequency echo signal to the radio frequency module;

The radio frequency module converts the radar intermediate frequency echo signal into the radar radio frequency echo signal.

Optionally, before generating radar-related parameters in different echo modes through an edit box, the multi-system agile radar RF echo signal simulation method further includes:

Detect whether the open TCP service button is activated, and if so, establish a communication link with the TCP protocol of the radar signal processing board.

Optionally, the DSP determines target information according to radar-related parameters of the data frame, and continuously constructs a PRT echo pulse signal model based on the target information and the original echo pulse data, and generates the Nth PRT echo pulse signal model. Delivered to the FPGA, count the total number of PRT echo pulse signal models that have been delivered to the FPGA; according to the total number and radar-related parameters, calculate the starting distance and data sampling points of N+1 PRT echo pulses, and construct the N+1th PRT echo pulse signal model, when receiving the request to send command sent by the FPGA, sending the N+1th PRT echo pulse signal model to the FPGA includes:

Step a: based on the target information and the original echo pulse data, construct the echo pulse signal model of the first PRT, and send the echo pulse signal model of the first PRT to the FPGA;

Step b: Count the total number of PRT echo pulse signal models that have been sent to the FPGA;

Step c: Calculate the starting distance and the number of data sampling points of the second PRT echo pulse signal model according to the total number and radar-related parameters;

Step d: construct the second PRT echo pulse signal model according to the starting distance and the number of data sampling points of the second PRT echo pulse signal model;

Step e: sending the second PRT echo pulse signal model to the FPGA when receiving the request to send instruction sent by the FPGA;

Step f: Calculate the starting distance and the number of data sampling points of the N+2th PRT echo pulse signal model according to the total number of statistics of N+1 and radar-related parameters;

Step g: construct the N+2th PRT echo pulse signal model according to the starting distance and the number of data sampling points of the N+2th PRT echo pulse signal model;

Step h: when receiving the request to send instruction sent by the FPGA, send the N+2th PRT echo pulse signal model to the FPGA, and return to step f.

Optionally, the echo mode selection box, used to switch the system type of the output RF echo signal agilely;

The system types include: MIMO mode, frequency agile mode, and phased array mode.

Optionally, in the frequency agile mode, the carrier frequency sequence f _m is randomly generated according to the frequency hopping codeword; determining the target information according to the radar-related parameters of the data frame includes:

The DSP, in the frequency agile mode, simulates the discontinuous phase parameter characteristic of the echo pulse signal of the frequency agility system caused by the carrier frequency agility between pulses according to the carrier frequency sequence f _m in the radar related parameters;

The feature is used as the feature of the target to determine target information.

Optionally, after generating the original echo pulse data according to the radar-related parameters,

The host computer software sets its own edit box to a non-editable state.

Optionally, after the radio frequency module converts the radar intermediate frequency echo signal into the radar radio frequency echo signal, the method for simulating the multi-system agile radar radio frequency echo signal further includes:

The host computer software detects whether the reset button generates a reset command, and if the reset command is detected, the reset command is sent to the DSP, and its own edit box is set to an editable state;

The DSP resets and clears the stored data frame and the PRT echo pulse signal model.

Optionally, after the radio frequency module converts the radar intermediate frequency echo signal into the radar radio frequency echo signal, the multi-system agile radar radio frequency echo signal simulation method further includes:

The host computer software, when detecting the attenuation command generated by the attenuation enable button, sends the attenuation command to the FPGA through the DSP;

The FPGA sends an attenuation instruction to the radio frequency module through the serial port;

The radio frequency module is used to adjust the output power of the radio frequency echo signal.

Beneficial effects of the present invention:

1) The present invention provides a multi-system agile radar radio frequency echo signal simulation method, which can realize the use of less software and hardware resources to complete the multi-system radar echo real-time simulation system design, and greatly reduce the radar echo signal. Simulate the cost and size of the system.

2) The present invention can realize the integration of radar echo signal simulation software of various systems, and can use the host computer interface to switch in real-time agility to complete the simulation of radar echo signals of various systems in the same continuous echo acquisition test, and operate the system. Has great flexibility.

3) The present invention adopts the ping-pong operation to realize the radar echo signal generation method, when the FPGA end receives a group of new PRT echo data, the echo data is placed on the RAM address where the just output group of PRT echo data is located, By updating the original PRT echo data in real time, and updating the parameters such as the starting distance of the PRT and the number of data sampling points, the ping-pong operation can be realized, which can save FPGA logic resources and improve time utilization.

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

Description of drawings

1 is a flowchart of a method for simulating a multi-system agile radar radio frequency echo signal provided by an embodiment of the present invention;

Fig. 2 is a kind of multi-system agile radar echo real-time simulation system design flow chart of the present invention;

Fig. 3 is the radar echo real-time simulation system upper computer operation interface designed by the present invention;

FIG. 4 is a flow state diagram of the real-time signal processing method of the multi-system agile radar echo real-time simulation system of the present invention.

Detailed ways

The present invention will be described in further detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

Aiming at the problems of poor real-time signal processing and single application scenario of the existing radar echo simulator system, the invention provides a multi-system agile radar radio frequency echo signal simulation method, which is mainly applied to the phased array system/MIMO system/ Real-time simulation of the RF echo signal of a frequency-agile system radar. The simulation method of the present invention is applied to a communication server and a radar signal processing board, wherein the communication server is communicatively connected to the radar signal processing board, and is characterized in that the radar signal processing board consists of a DSP, an FPGA chip, It is composed of DA module, radio frequency module and peripheral circuit.

As shown in FIG. 1, a multi-system agile radar radio frequency echo signal simulation method provided by the present invention includes:

Step 1: Establish the host computer software on the communication server for sending radar-related parameters to the radar signal processing board;

Among them, the host computer software includes a software interface, the software interface includes: radar-related parameter editing box and function buttons, and the radar-related parameter editing box includes X for echo mode selection, echo quantization amplitude Amp, and the number of PRTs in a CPI kk , the number of time-width sampling points nTp within a pulse width _Tp , the target distance range R_range, the echo starting distance R, the target speed V _r , the echo pulse repetition period PRT, the carrier frequency sequence f _m , the echo beam pitch angle fai0 And the input box of the echo beam azimuth theta0 parameter; the function buttons include the button to generate echo data, the button to start the TCP service, the button to start sending data, the button to reset and the button to enable attenuation;

It is worth noting that the upper computer software runs on a computer system, and the upper computer operation control interface is written based on MATLAB software. In this interface, an editing box for related parameters such as radar system selection is designed, including echo mode selection X, echo quantization amplitude Amp , the number of PRTs kk in one CPI, the number of time-width sampling points nTp in one _Tp (pulse width), the target distance range R_range, the echo starting distance R, the target speed V _r , the echo pulse repetition period PRT, calculation According to the parameters such as carrier frequency sequence f _m , echo beam pitch angle fai0 , echo beam azimuth angle theta0 generated by frequency hopping codeword, and design function buttons, the function buttons include generate echo data button, open TCP service button, start sending Data button, reset button and attenuation enable button, develop the original echo pulse data generation program and data framing program under each system.

Step 2: On the software interface of the host computer software, use the echo mode selection button to switch between different echo modes, and use the edit box to generate radar-related parameters in different echo modes. When operating the command, the original echo pulse data is generated according to the radar-related parameters, and the radar-related parameters and the original echo pulse data are formed into a data frame;

Among them, the echo mode selection box is used to agilely switch the system type of the RF echo signal output by the simulation during the RF echo simulation process;

The system types include: MIMO mode, frequency agile mode, and phased array mode.

It can be understood that the present invention can switch agilely through the echo mode. That is, during the same radar echo simulation process, if you need to switch the current simulated echo type, you can preset the radar parameters on the host computer, click the echo mode button to switch the radar system mode, and the host computer can quickly change the current system radar echo. The simulation module enters the radar echo simulation module of the corresponding system, and sends it to the DSP through the Ethernet. When the DSP receives the data, it will quickly respond to the command and send the updated echo data to the FPGA in the next pulse repetition cycle. , to complete the radar waveform type switching, the overall time from issuing the command to completing the switching does not exceed one pulse repetition period.

Among them, after generating the original echo pulse data according to the radar-related parameters, the host computer software sets its own edit box to an uneditable state.

Step 3: Select the button to start sending data, and send the data frame to the DSP in the radar signal processing board;

Referring to Figure 2, the host computer sends the completed frame header, command parameters, original echo pulse data and frame tail to the DSP through Ethernet: After the parameters are set, click the echo signal send button on the host computer operation interface, The host computer sends the data frame to the DSP side of the signal processing board through the Ethernet port, and when the DSP identifies the frame header and frame end of the data frame, the valid data instruction information is cached in the DDR3 chip;

Step 4: The DSP determines the target information according to the radar-related parameters of the data frame, and continuously constructs the PRT echo pulse signal model based on the target information and the original echo pulse data, and sends the Nth PRT echo pulse signal model to the FPGA, Count the total number of PRT echo pulse signal models that have been sent to the FPGA; according to the total number and radar-related parameters, calculate the starting distance and data sampling points of N+1 PRT echo pulses, and construct the N+1 th PRT echo pulse signal Model, when receiving the request to send command sent by FPGA, send the N+1th PRT echo pulse signal model to FPGA;

Among them, N is a positive integer starting from 1;

Referring to Figure 2, the DSP parses the data instruction information sent by the host computer according to the protocol, starts to construct the first PRT echo pulse signal model, loads the target information, and generates echo pulse data. And calculate the starting distance of the starting distance of the PRT echo pulse and the number of data sampling points, send the data packet to the FPGA through the SRIO data link according to the data format protocol, and count the number of sent PRTs at the same time, and start to generate the second one. The echo pulse data of the PRT, calculate the echo pulse starting distance and data sampling points of the second PRT, wait for the FPGA to send the request command code B, and request the DSP to send the echo pulse data of the first PRT;

Step 5: FPGA, store the Nth PRT echo pulse signal model, and output the Nth PRT echo pulse signal model to the DA module according to the echo simulation output command generated by itself;

Referring to Figure 2, the FPGA receives and analyzes the data packets transmitted by SRIO: the FPGA side latches the echo pulse data transmitted by the first DSP, and parses out the starting distance value, the data sampling point value and the echo pulse of the first PRT. data, cache the received first PRT echo pulse data in RAM, which is used to store the echo pulse data of one PRT under different systems. The data receiving module is switched according to different systems. When the echo pulse data of a PRT has been buffered in the RAM, a status signal is generated to indicate that the data can be fetched from the RAM.

Design the sending state machine on the FPGA side, and the DA chip outputs the simulated radar echo signal: after the DA chip is powered on, it outputs a non-echo signal with an amplitude of 0 by default. In the sending state machine, the default state is 00. This state waits for the first time the PRT enable signal is pulled high, starts timing and jumps to state 01, and when state 1 keeps timing to the starting position value of the target echo, the sending state machine jumps to state 02. The PRT enable signal is a PRT cycle signal that controls the entire echo. When PRT is enabled once, it means that the echo output of one PRT cycle is started. In state 02, the echo pulse data in the RAM buffer is read, the data is sent to the DA chip, and the DA chip is enabled to output the echo pulse signal until the reading is completed. The state of the sending state machine jumps to 03; in the 03 state, the request command code B is generated, and the request command code B is sent to the DSP, and the DSP is requested to send the echo pulse data of the second PRT, and the state jumps to the state 00, waiting for the PRT Enable signal, ready to output the echo signal of the second PRT.

The DSP receives the request instruction code B sent by the FPGA, clears the array contents in the DDR3 cache, sends the data packet to the FPGA through the SRIO data link according to the data format protocol, and counts the number of sent PRTs, and starts to generate the third PRT The echo pulse data, calculate the starting distance and data sampling points of the third PRT echo pulse, wait for the FPGA to send the request command code B, and request the DSP to send the echo pulse data of the second PRT. Next, according to the real-time signal processing method described in the present invention, the real-time IF echo pulse signal simulation of the multi-system radar is completed on the signal processing board.

Step 6: the DA module generates a simulated radar intermediate frequency echo signal according to the Nth PRT echo pulse signal model, and outputs the radar intermediate frequency echo signal to the radio frequency module;

Step 7: the radio frequency module converts the radar intermediate frequency echo signal into the radar radio frequency echo signal.

Referring to Figure 2, the IF echo analog signal generated in real time is input to the radio frequency combination module, and the intermediate frequency signal is up-converted to the radio frequency to complete the real-time radar RF echo signal simulation. By setting the RF power attenuation value on the upper computer operation interface, the power of the output RF echo can be controlled in real time.

The invention provides a multi-system agile radar radio frequency echo signal simulation method. The software and hardware are combined to write the upper computer software of the radar echo real-time simulation system; the data frame is sent to the DSP; the DSP starts to construct according to the data frame. Echo pulse signal model, load target information, and generate echo pulse data; DSP receives the request instruction code B sent by FPGA, clears the array content of DDR3 cache, and sends data packets; FPGA receives and analyzes the data packets transmitted by SRIO and designs the data packets The state machine outputs the simulated radar echo signal from the DA chip; the real-time generated intermediate frequency echo analog signal is input to the microwave radio frequency combination module, and the intermediate frequency signal is up-converted to the radio frequency to complete the real-time radar radio frequency echo signal simulation. Therefore, the simulation method of the present invention can realize multi-system agility and better real-time radar RF signal echo simulation.

As an optional implementation manner of the present invention, before generating radar-related parameters in different echo modes through an edit box, the method for simulating a multi-system agile radar radio frequency echo signal further includes:

Detect whether the Open TCP service button is activated, if so, establish a communication link with the TCP protocol of the radar signal processing board.

As an optional embodiment of the present invention, step 4 includes:

Step a: Based on the target information and the original echo pulse data, construct the echo pulse signal model of the first PRT, and send the echo pulse signal model of the first PRT to the FPGA;

Step b: Count the total number of PRT echo pulse signal models that have been sent to the FPGA;

Step c: Calculate the starting distance and the number of data sampling points of the second PRT echo pulse signal model according to the total number and radar-related parameters;

Step d: construct the second PRT echo pulse signal model according to the starting distance and the number of data sampling points of the second PRT echo pulse signal model;

Step e: sending the second PRT echo pulse signal model to the FPGA when receiving the request to send instruction sent by the FPGA;

Step f: Calculate the starting distance and the number of data sampling points of the N+2th PRT echo pulse signal model according to the total number of statistics of N+1 and radar-related parameters;

Step g: construct the N+2th PRT echo pulse signal model according to the starting distance and the number of data sampling points of the N+2th PRT echo pulse signal model;

Step h: when receiving the request to send instruction sent by the FPGA, send the N+2th PRT echo pulse signal model to the FPGA, and return to step f.

As an optional implementation manner of the present invention, in the frequency agile mode, the carrier frequency sequence f _m is randomly generated according to the frequency hopping codeword; determining the target information according to the radar-related parameters of the data frame includes:

DSP, in the frequency agile mode, according to the carrier frequency sequence f _m in the radar related parameters, simulate the discontinuous phase parameters of the echo pulse signal of the frequency agile system caused by the carrier frequency agility between pulses;

The feature is used as the feature of the target to determine the target information.

As an optional embodiment of the present invention, after the radio frequency module converts the radar intermediate frequency echo signal into the radar radio frequency echo signal, the method for simulating the radar radio frequency echo signal of multi-system agility further includes:

The host computer software detects whether the reset button generates a reset command. If a reset command is detected, the reset command is sent to the DSP, and its own edit box is set to an editable state;

The DSP resets and clears the data frame stored by itself and the PRT echo pulse signal model.

As an optional embodiment of the present invention, after the radio frequency module converts the radar intermediate frequency echo signal into the radar radio frequency echo signal, the method for simulating the radar radio frequency echo signal of multi-system agility further includes:

The host computer software, when detecting the attenuation command generated by the attenuation enable button, sends the attenuation command to the FPGA through the DSP;

The FPGA sends the attenuation command to the RF module through the serial port;

The radio frequency module is used to up-convert the intermediate frequency signal to the radio frequency signal and adjust the output power of the radio frequency echo signal.

The specific process of a method for simulating a multi-system agile radar radio frequency echo signal of the present invention is described below by means of an embodiment.

Example 1

The present invention compiles the host computer software of the radar echo real-time simulation system. Referring to FIG. 3 , the parameter editing window such as radar system selection and function buttons are designed in the software. The function buttons include a button to generate echo data, a button to open a TCP service, and a button to start sending data. button, reset button and attenuation enable button, design the original echo data generation program and data framing program under each system, including the following steps:

(1a) Set the radar system: phased array mode X=1, MIMO mode X=2, frequency agile mode X=3;

(1b) Set the target distance range R_range: It is determined by the set radar system parameters, and the calculation formula is as follows:

Maximum working distance:

Rmax=Unambi_Range=PRT*C/2 (1)

Minimum action distance:

R _min =T _p *C/2 (2)

According to different modes, the maximum operating distance and the minimum operating distance of the radar echo can be calculated, and the movable distance range R_range=[R _max R _min ] of the target can be obtained.

(1c) Set the echo starting distance R: under different systems and parameters, the range of the distance that the target can move is different, which can be set according to the specific mode;

(1d) Set the target speed V _r : the target speed can be positive or negative; if the specified speed is positive, it means that the distance to the target is getting closer, and vice versa, it means that the distance to the target is getting farther and farther;

(1e) Set the pulse repetition period PRT: used to calculate the speed phase term, the starting distance of PRT and other information;

(1f) Set the carrier frequency sequence f _m and the number of PRTs in a CPI kk: Different modes have different requirements for the carrier frequency of the simulated radar echo. The simulator sets the length of the carrier frequency sequence to 256, corresponding to one CPI The carrier frequency of the 256 PRTs. The number of PRTs kk in a CPI and the corresponding carrier frequency sequence can be adjusted according to the different modes selected. In phased array mode, set the number kk of PRTs in a CPI to 64, the first 64 carrier frequency sequences are a fixed value, and the rest are set to 0; in MIMO mode, set the number of PRTs kk in a CPI to 256, 256 carrier frequency sequences are a fixed value; in frequency agile mode, set the number of PRTs kk in a CPI to 64, the first 64 carrier frequency sequences are randomly hopping carrier frequency sequences, and the rest are set to 0;

(1g) Set the echo quantization amplitude Amp

The amplitude of echo quantization is determined according to the demand.

(1h) The original echo data and the number of sampling points nT _p in one Tp

The formula for calculating the number of sampling points is as follows:

nT _p =T _p *F _s (3)

The original echo simulates an intermediate frequency linear frequency modulation wave. Due to the different radar parameters in the three modes, the simulated radar echo data and the number of sampling points nT _p are different. The expression of the original intermediate frequency echo data within the width is shown in formula (4).

Slfm=(exp(j*pi*u*t.^2).exp(j*2*pi*Fi*t)) (4)

u=B/T _p is the frequency modulation slope, F _i is the intermediate frequency frequency, it is uniformly stipulated that the amplitude of the intermediate frequency signal echo is the normalized modulus value 1. The final signal amplitude is determined by the amplitude quantization value Amp.

In MIMO mode, 12 orthogonal intermediate frequency echo waveforms need to be designed. The original echo data is obtained by determining the transmitting and receiving steering vector, constructing the baseband signal, up-converting the frequency to the intermediate frequency, and simulating the original echo according to the steering vector. The calculation method of the steering vector of its transmission and reception is shown in formula (5) (6) (7).

az0=exp(-j*2*pi*d_lambda*[-1.5 -0.5 0.5 1.5]'*sin(θ)) (6)

aa0=kron(ay0,az0) (7)

为俯仰角，θ为方位角

及θ均在上位机操作界面设置。d_lambda is the ratio of subarray spacing to wavelength,

is the pitch angle, θ is the azimuth angle

and θ are set in the upper computer operation interface.

Select the steering vectors and form them into the vector form aat, which are the steering vectors of the 12 sub-arrays of the radar phased array antenna, respectively. Multiply the steering vectors of the 12 sub-arrays with the original orthogonal echo model, and the synthesized echo beam will be obtained. . The 12-channel original quadrature intermediate frequency echo waveform expression is shown in formula (8).

u=B/T _p is the frequency modulation slope, F _i is the intermediate frequency frequency, it is uniformly stipulated that the amplitude of the intermediate frequency signal echo is the normalized modulus value 1. The IF frequency interval of the adjacent two orthogonal signals is B, and the final signal amplitude is determined by the amplitude quantization value Amp. The 12-channel quadrature IF echo signals are assembled into a vector form.

The 12-channel orthogonal radar echo waveform data is multiplied by the steering vector, and finally the original signal echo data of the synthesized MIMO waveform synthesized beam is obtained. As shown in formula (9).

Slfm=(aat).'*Signal (9)

1i) Set the button to start sending data

After the parameters are set, click the Start Sending Data button to frame the parameter data.

1j) Set the reset button

This button can reset the current state of all modules of the radar echo real-time simulation system.

1k) Set the attenuation enable button

Input the attenuation command value and click the attenuation control button to control the RF output power. The relationship between the attenuation command value and the actual attenuation value is as follows, the default attenuation value is the maximum attenuation.

Example 2

With Embodiment 1, the DSP of the present invention parses the data instruction information issued by the host computer according to the protocol, and starts to construct the echo pulse signal model of each PRT, which specifically includes the following steps:

1a) Identify the radar system mode command issued by the host computer, enter different echo building modules according to different modes, retrieve all commands from DDR3, and retrieve the original echo data from DDR3 according to the number of sampling points;

1b) Load echo information

Load the target information into the target echo raw data, and the echo target information loading methods in different modes are slightly different.

Phased Array Mode

Among them, PRT is the pulse repetition period sent by the host computer, V _r is the target speed, kk represents the number of PRTs, and the number of PRTs in a CPI is 64. The target information is modulated within the pulse width of each PRT, and the starting distance of each PRT is calculated according to the sent target echo starting distance. After calculating the echo data of a PRT, the result and the corresponding starting distance of the PRT are calculated. The distance is sent to the RAM side of the FPGA. The formula for calculating the starting distance of the echo is as follows:

start_pos=fix((R-(kk-1)*V _r *PRT)/(C/(2*F _s ))/2) (11)

where kk represents the kkth PRT, the speed of light C=3×10 ⁸ m/s, and F _s is the sampling frequency.

MIMO mode

Among them, PRT is the pulse repetition period sent by the host computer, V _r is the target speed, kk represents the number of PRTs, and the number of PRTs in a CPI is 256. The target information is modulated within the pulse width of each PRT, and the starting distance of each PRT is calculated according to the sent target echo starting distance. After calculating the echo data of a PRT, the result and the corresponding starting distance of the PRT are calculated. The distance is sent to the RAM side of the FPGA. The formula for calculating the starting distance of the echo is as follows:

start_pos=fix((R-(k-1)*V _r *PRT)/(C/(2*F _s ))/2) (13)

where kk represents the kkth PRT, the speed of light C=3×10 ⁸ m/s, and F _s is the sampling frequency.

Frequency Agile Mode

Among them, PRT is the pulse repetition period sent by the host computer, V _r is the target speed, kk represents the number of PRTs, and the number of PRTs in one CPI is 64. The target information is modulated within the pulse width of each PRT, and the starting distance of each PRT is calculated according to the sent target echo starting distance. After calculating the echo data of a PRT, the result and the starting distance corresponding to the PRT are calculated. Sent to the RAM side of the FPGA. The formula for calculating the starting distance of the echo is as follows:

start_pos=fix((R-(k-1)*V _r *PRT)/(C/(2*F _s ))/2) (15)

where kk represents the kkth PRT, the speed of light C=3×10 ⁸ m/s, and F _s is the sampling frequency.

1c) Frame the data according to the frame header + the starting distance of the echo pulse + the number of data sampling points + the echo pulse data loaded with the target information + the data packet protocol at the end of the frame, and wait for the FPGA to send a data request command.

Example 3

Referring to Figure 4, the same as in Embodiment 1,

1a) The FPGA sends the data request instruction code B to the DSP, and receives and analyzes the data packets transmitted by the SRIO: the FPGA side latches the data transmitted by the first DSP, and parses out the starting distance start_point, the number of data sampling points memory_depth and the first PRT The echo pulse data of the first PRT received is cached in the RAM, which is used to store the echo pulse data of one PRT under different systems. The data volume of each radar system varies. Different, FPGA needs to switch the data receiving module according to different systems. When the echo data of a PRT has been buffered in the RAM, a status signal is generated to indicate that the data can be fetched from the RAM;

1b) Design the sending state machine on the FPGA side, and the DA chip outputs the simulated radar echo signal: In the sending state machine, the default state is 00. In this state, after the first PRT enable signal is pulled high, the DA The chip starts to be enabled, starts to output non-pulse signal whose amplitude is 0, cnt_1 starts counting and jumps to state 01, cnt_1 counter in state 01 has been counting to the starting position value of the target echo. The PRT enable signal is a PRT cycle signal that controls the entire echo. Once PRT is enabled, it means that the echo output of a PRT cycle is started;

1c) When the count value of cnt_1 reaches the starting position value, the sending state machine jumps to state 02. At this time, it starts to read the echo pulse data in the RAM, and addrb starts to increment by 1 until it reaches the echo pulse data of this PRT. Sampling points. At the same time, the DA chip starts to output the simulated radar echo pulse signal;

1d) When the RAM's B port addrb counts to memory_depth-1, the DA chip finishes the echo data of this PRT, and the state of the sending state machine jumps to 03; in the 03 state, pull up srio_cmd_tx for 10 200MHz clock cycles, resulting in srio_cmd_tx_pos pulse, send the request command code B to the DSP, request the DSP to send the data of the second PRT, at the same time the state jumps to state 00, wait for the PRT enable signal, and prepare to output the echo signal of the second PRT;

1e) The DSP receives the request instruction code B sent by the FPGA, clears the array content in the DDR3 cache, sends the data packet to the FPGA through the SRIO data link according to the data format protocol, and counts the number of PRTs that have been sent, and starts to generate the third The echo data of each PRT, calculate the starting distance and the number of data sampling points of the third PRT, wait for the FPGA to send the request command code B, and request the DSP to send the echo data of the third PRT. Next, according to the real-time signal processing method described in the present invention, the real-time RF echo signal simulation of the multi-system radar is completed on the signal processing board.

The above content is a further detailed description of the present invention in combination with specific preferred embodiments, and it cannot be considered that the specific implementation of the present invention is limited to these descriptions. For those of ordinary skill in the technical field of the present invention, without departing from the concept of the present invention, some simple deductions or substitutions can be made, which should be regarded as belonging to the protection scope of the present invention.

Claims (8)

1. A multi-system agile radar radio frequency echo signal simulation method is applied to a communication server and a radar signal processing board, and the communication server is communicatively connected with the radar signal processing board, and it is characterized in that, the radar The signal processing board is composed of a DSP, an FPGA chip, a radio frequency module, a DA module and a peripheral circuit; the simulation method includes: Establish the host computer software for sending radar-related parameters to the radar signal processing board on the communication server; Wherein, the host computer software includes a software interface, the software interface includes: a radar-related parameter editing box and function buttons, and the radar-related parameter editing box includes an echo selection X, an echo quantization amplitude Amp, a CPI internal The number of PRTs kk, the number of time-width sampling points nTp within a pulse width _Tp , the target distance range R_range, the echo starting distance R, the target speed V _r , the echo pulse repetition period PRT, the carrier frequency sequence f _m , the echo pulse Beam pitch angle fai0 and the input box of echo beam azimuth angle theta0 parameter; Described function button includes generate echo data button, open TCP service button, start sending data button, reset button and attenuation enable button; In the software interface of the host computer software, the echo mode is switched agilely through the echo mode selection button, and the radar-related parameters are generated in different echo modes through the edit box. When receiving the operation command of the button to generate echo data , generating original echo pulse data according to the radar-related parameters, and forming a data frame with the radar-related parameters and the original echo pulse data; Select the button to start sending data, and send the data frame to the DSP in the radar signal processing board; The DSP determines target information according to the radar-related parameters of the data frame, continuously constructs a PRT echo pulse signal model based on the target information and the original echo pulse data, and sends the Nth PRT echo pulse signal model to the FPGA , count the total number of PRT echo pulse signal models that have been sent to the FPGA; according to the total number and radar-related parameters, calculate the starting distance of N+1 PRT echo pulses and the number of data sampling points, and construct the N+1th PRT echo pulse Signal model, when receiving the request to send command sent by FPGA, send the N+1th PRT echo pulse signal model to FPGA; Among them, N is a positive integer starting from 1; The FPGA stores the Nth PRT echo pulse signal model, and outputs the Nth PRT echo pulse signal model to the DA module according to the echo simulation output instruction generated by itself; The DA module generates a simulated radar intermediate frequency echo signal according to the Nth PRT echo pulse signal model, and outputs the radar intermediate frequency echo signal to the radio frequency module; The radio frequency module converts the radar intermediate frequency echo signal into the radar radio frequency echo signal. 2. The multi-system agile radar radio frequency echo signal simulation method according to claim 1, characterized in that, before generating radar-related parameters through an edit box in different echo modes, the multi-system agile The radar RF echo signal simulation method also includes: Detect whether the open TCP service button is activated, and if so, establish a communication link with the TCP protocol of the radar signal processing board. 3 . The multi-system agile radar radio frequency echo signal simulation method according to claim 1 , wherein the DSP determines target information according to radar-related parameters of the data frame, and based on the target information and the original echo signal. 4 . The PRT echo pulse signal model is continuously constructed from the pulse data, and the Nth PRT echo pulse signal model is sent to the FPGA, and the total number of PRT echo pulse signal models that have been sent to the FPGA is counted; Calculate the starting distance and data sampling points of the N+1 PRT echo pulse, and construct the N+1 PRT echo pulse signal model. When receiving the request to send command sent by the FPGA, the N+1 PRT echo pulse The signal model sent to the FPGA includes: Step a: based on the target information and the original echo pulse data, construct the echo pulse signal model of the first PRT, and send the echo pulse signal model of the first PRT to the FPGA; Step b: Count the total number of PRT echo pulse signal models that have been sent to the FPGA; Step c: Calculate the starting distance and the number of data sampling points of the second PRT echo pulse signal model according to the total number and radar-related parameters; Step d: construct the second PRT echo pulse signal model according to the starting distance and the number of data sampling points of the second PRT echo pulse signal model; Step e: sending the second PRT echo pulse signal model to the FPGA when receiving the request to send instruction sent by the FPGA; Step f: Calculate the starting distance and the number of data sampling points of the N+2th PRT echo pulse signal model according to the total number of statistics of N+1 and radar-related parameters; Step g: construct the N+2th PRT echo pulse signal model according to the starting distance and the number of data sampling points of the N+2th PRT echo pulse signal model; Step h: when receiving the request to send instruction sent by the FPGA, send the N+2th PRT echo pulse signal model to the FPGA, and return to step f. 4. The multi-system agile radar radio frequency echo signal simulation method according to claim 3, wherein the echo mode selection frame is used for agile switching of the system type of the output radio frequency echo signal; The system types include: MIMO mode, frequency agile mode, and phased array mode. 5 . The multi-system agile radar radio frequency echo signal simulation method according to claim 4 , wherein, in the frequency agile mode, the carrier frequency sequence f _m is randomly generated according to a frequency hopping codeword. 6 . ; Determine the target information according to the radar-related parameters of the data frame, including: The DSP, in the frequency agile mode, simulates the discontinuous phase parameter characteristic of the echo pulse signal of the frequency agility system caused by the carrier frequency agility between pulses according to the carrier frequency sequence f _m in the radar related parameters; The feature is used as the feature of the target to determine target information. 6 . The multi-system agile radar radio frequency echo signal simulation method according to claim 1 , wherein after generating original echo pulse data according to the radar-related parameters, The host computer software sets its own edit box to a non-editable state. 7. The multi-system agile radar radio frequency echo signal simulation method according to claim 1, wherein, in the radio frequency module, after the radar intermediate frequency echo signal is converted into a radar radio frequency echo signal, the multi-system agile The simulation method of the variable radar RF echo signal also includes: The host computer software detects whether the reset button generates a reset command, and if the reset command is detected, the reset command is sent to the DSP, and its own edit box is set to an editable state; The DSP resets and clears the data frame stored by itself and the PRT echo pulse signal model. 8. The multi-system agile radar radio frequency echo signal simulation method according to claim 1, wherein after the radio frequency module converts the radar intermediate frequency echo signal into a radar radio frequency echo signal, the multi-system agility The radar RF echo signal simulation method also includes: The host computer software, when detecting the attenuation command generated by the attenuation enable button, sends the attenuation command to the FPGA through the DSP; The FPGA sends an attenuation instruction to the radio frequency module through the serial port; The radio frequency module is used to adjust the output power of the radio frequency echo signal.

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