Multi-channel 4GHz bandwidth radar radiation source signal generation system and method

Abstract

The invention relates to the technical field of wireless communication, and discloses a multichannel 4GHz bandwidth radar radiation source signal generation system and method. The method comprises the following steps: acquiring radar baseband excitation data; multiplying the radar baseband excitation data by the corresponding amplitude-phase compensation coefficient to obtain target excitation data so as to realize amplitude-phase calibration of the radar baseband excitation signal; sequentially carrying out double interpolation, filtering and first frequency mixing on the obtained target excitation data to obtain an intermediate frequency signal with a preset sampling rate; and performing second frequency mixing on the intermediate frequency signal, and amplifying the intermediate frequency signal to preset power to generate a radar radiation source signal. According to the method, the instantaneous signal bandwidth of a radar system is greatly improved by improving the sampling rate, and the amplitude-phase consistency automatic calibration of a multi-channel large-bandwidth radar radiation source signal generation system in a rapid, full-band and full-dynamic range is realized through an automatic amplitude-phase calibration process.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technology, and in particular to a multi-channel 4 GHz bandwidth radar radiation source signal generation system and method. Background Art

[0002] As a radio device, radar has a wide range of uses and is closely related to our lives, including air and ground traffic control, radar air defense, radar anti-missile, aircraft collision avoidance, ocean surveillance, meteorological precipitation monitoring, height measurement, speed measurement, etc. The radar radiation source signal generation system is used to simulate radar signal output. The instantaneous signal bandwidth is an important parameter of the radar, which determines the performance and accuracy of the radar system. The larger the bandwidth, the higher the accuracy of the system, but at the same time, the bandwidth will also increase the complexity and cost of the system. In radar-related systems, the larger the bandwidth, the more complex the analog circuits that need to be used, and a higher-speed digital-to-analog converter and digital signal processor are required.

[0003] In the process of multi-channel radar radiation source signal simulation and antenna array testing, poor amplitude and phase consistency between channels will cause a series of problems such as changes in the direction of the antenna's transceiver beam, beam widening, increased side lobes, and decreased antenna gain, which will lead to a decline in radar system performance, inaccurate test results, or even failure to work. Therefore, calibration of system amplitude and phase consistency is an inevitable problem. If manual calibration is used, it has the disadvantages of low calibration efficiency, inaccurate calibration, and incomplete coverage. Summary of the invention

[0004] In view of this, the present invention provides a multi-channel 4 GHz bandwidth radar radiation source signal generating system and method to solve the problems of low instantaneous bandwidth of the current radar radiation source signal generating system and poor amplitude consistency between channels of the multi-channel radar radiation source signal generating system.

[0005] In a first aspect, the present invention provides a multi-channel 4 GHz bandwidth radar radiation source signal generation system, the system comprising:

[0006] A main control module, the main control module includes a COME board, the COME board is buckled on the signal generating module through a connector, the COME board is integrated with a PCIE interface, and is connected to the signal generating module through the PCIE interface. The main control module is used to control the signal generating module to generate a radar radiation source signal;

[0007] A signal generating module, comprising 2 FPGA chips, 2 ADC chips and 8 DAC chips, each FPGA chip being electrically connected to one ADC chip and four DAC chips;

[0008] A radio frequency module comprises one down-conversion channel, eight up-conversion channels and eight local oscillators; wherein each up-conversion channel is electrically connected to the DAC chip; the down-conversion channel is electrically connected to the ADC chip; the eight local oscillators are respectively connected to the eight up-conversion channels, and any one of the eight local oscillators is powered into eight paths, of which seven paths are respectively connected to the remaining seven local oscillators, and the remaining seven local oscillators all comprise single or double switches, and the single or double switches are used to switch local oscillator signals, so as to realize eight-channel independent local oscillators or common local oscillators, and the radio frequency module is used to transmit the radar radiation source signal.

[0009] The multi-channel 4GHz bandwidth radar radiation source signal generation system provided by the embodiment of the present invention realizes a high degree of integration and modularization of the system through a clear division of the main control module, the signal generation module and the radio frequency module, so that the system structure is clear and easy to maintain, upgrade and expand. By integrating two large-scale high-performance FPGA chips, the high parallel processing capability of the FPGA chip is better utilized to efficiently process complex radar signal generation algorithms and improve the accuracy and speed of signal processing. Each FPGA is equipped with one ADC chip and four DAC chips, which are used for intermediate frequency signal acquisition and intermediate frequency signal playback during closed-loop calibration, respectively, which not only ensures that the output of the intermediate frequency signal has a high amplitude and phase consistency, but also achieves a larger instantaneous bandwidth.

[0010] In an optional implementation, the maximum sampling rates of the ADC chip and the DAC chip are not less than 10 GSps.

[0011] The multi-channel 4 GHz bandwidth radar radiation source signal generation system provided by the embodiment of the present invention adopts a high sampling rate chip to collect more data points per unit time, thereby improving the resolution of the signal and providing a hardware foundation for the system to achieve an instantaneous bandwidth of 4 GHz.

[0012] In a second aspect, the present invention provides a method for generating a multi-channel 4 GHz bandwidth radar radiation source signal, which is applied to the above system, and the method comprises:

[0013] Obtain radar baseband excitation data;

[0014] The radar baseband excitation data is multiplied by the corresponding amplitude and phase compensation coefficient to obtain the target excitation data, so as to realize the amplitude and phase calibration of the radar baseband excitation signal;

[0015] The target excitation data is sequentially interpolated, filtered, and first mixed to obtain an intermediate frequency signal of a preset sampling rate;

[0016] The intermediate frequency signal is mixed for the second time and amplified to a preset power to generate a radar radiation source signal with a bandwidth of 4 GHz.

[0017] The multi-channel 4GHz bandwidth radar radiation source signal generation method provided by the embodiment of the present invention realizes the amplitude and phase calibration of the multi-channel signal by multiplying the radar baseband excitation data with the corresponding amplitude and phase compensation coefficient, thereby improving the accuracy and stability of the signal. Through the chip setting in the system, it is not only used for the collection and playback of the intermediate frequency signal, but also realizes the closed-loop calibration. This design further ensures that the output of the intermediate frequency signal has a high amplitude and phase consistency, and reduces signal distortion and errors.

[0018] In an optional implementation, the radar baseband excitation data is pre-generated playback data or real-time data;

[0019] When the radar baseband excitation data is pre-generated playback data, obtaining the radar baseband excitation data includes:

[0020] Generate a trigger pulse sequence according to radar parameters;

[0021] Based on the trigger pulse sequence, the radar baseband excitation data stored in the double data rate synchronous dynamic random access memory is read.

[0022] The multi-channel 4GHz bandwidth radar radiation source signal generation method provided by the embodiment of the present invention controls the reading of data through the trigger pulse sequence generated by the radar parameters, and can accurately control when to fetch data from the DDR SDRAM. At the same time, as a high-speed memory, the data access speed of the DDR SDRAM is much higher than that of the traditional storage medium. By controlling the reading of data through the trigger pulse, the high-speed access capability of the DDR SDRAM can be maximized, and the efficiency of data processing can be improved.

[0023] In an optional implementation, multiplying the radar baseband excitation data by the corresponding amplitude and phase compensation coefficient to obtain the target radar baseband excitation data includes:

[0024] The target amplitude and phase compensation coefficients are obtained by indexing the compensation coefficient database based on the frequency and power of the radar baseband excitation data; the compensation coefficient database is used to indicate the mapping relationship between the frequency and power and the amplitude and phase compensation coefficients;

[0025] Multiply the radar baseband excitation data with the corresponding amplitude and phase compensation coefficients to obtain the target excitation data.

[0026] The multi-channel 4 GHz bandwidth radar radiation source signal generation method provided by the embodiment of the present invention dynamically retrieves the corresponding amplitude and phase compensation coefficients from the compensation coefficient database according to the actual frequency and power of the radar baseband excitation data, and can achieve accurate calibration of signals at different frequencies and powers within a preset range. This dynamic compensation method is more flexible and accurate than a fixed compensation coefficient with a fixed range.

[0027] In an optional implementation, multiplying the radar baseband excitation data by the corresponding amplitude and phase compensation coefficient to obtain the target excitation data includes:

[0028] For the radar baseband excitation data, within the preset frequency and power range, the preset frequency and power step length is used for stepping, and multiple sets of adjusted radar excitation baseband data corresponding to each step length are collected;

[0029] Upload multiple sets of adjusted radar baseband data to the preset software for analysis to obtain single pulse signals corresponding to various frequencies and powers;

[0030] Calculate the corresponding real-time amplitude and phase compensation coefficient based on a single pulse signal;

[0031] The compensation coefficient database is updated based on the real-time amplitude and phase compensation coefficients.

[0032] The multi-channel 4GHz bandwidth radar radiation source signal generation method provided by the embodiment of the present invention can dynamically adapt to the calibration requirements of radar baseband excitation data at different frequencies and powers by calculating real-time amplitude and phase compensation coefficients, ensuring the amplitude and phase consistency of the signal during transmission and processing. The compensation coefficient database is updated based on the real-time calculated amplitude and phase compensation coefficients, ensuring that the compensation coefficients in the database are always consistent with the actual working state of the radar system.

[0033] In an optional implementation, if the single pulse signal is a single-point frequency signal, the corresponding real-time amplitude-phase compensation coefficient is calculated based on the single pulse signal, including:

[0034] Based on the frequency and power of the single-point frequency signal, acquiring a reference signal corresponding to the single-point frequency signal;

[0035] The single-point frequency signal and the reference signal are respectively subjected to fast Fourier transform to obtain the real-time amplitude-phase compensation coefficient.

[0036] The multi-channel 4GHz bandwidth radar radiation source signal generation method provided by the embodiment of the present invention is relatively simple and stable for single-point frequency signals due to its frequency and phase characteristics. Therefore, by comparing a single pulse signal with a reference signal, the amplitude and phase compensation coefficient can be accurately calculated to achieve accurate calibration of the signal. By calculating the real-time amplitude and phase compensation coefficient based on the comparison between a single pulse signal and a reference signal, the automation of the calibration process can be achieved, reducing the need for manual intervention and manual adjustment, while also ensuring that the calibration results at different times and conditions are consistent, thereby improving the stability and reliability of the system.

[0037] In an optional implementation, if the single pulse signal is a bandwidth signal, the corresponding real-time amplitude and phase compensation coefficient is calculated based on the single pulse signal, including:

[0038] Constructing an amplitude-phase compensation filter, wherein the order of the amplitude-phase compensation filter is a preset value;

[0039] A matrix is ​​constructed based on radar baseband excitation data; the number of columns of the matrix is ​​the order of the amplitude and phase compensation filter;

[0040] Based on the least square method, the coefficients of the amplitude and phase compensation filter are obtained.

[0041] The multi-channel 4 GHz bandwidth radar radiation source signal generation method provided in the embodiment of the present invention takes into account that the amplitude and phase characteristics of the bandwidth signal may be affected by various factors and change. Therefore, by real-time calculation and application of the amplitude and phase compensation coefficients, the amplitude and phase characteristics of the signal can be accurately calibrated to ensure that the signal maintains high quality during transmission and processing.

[0042] In a third aspect, the present invention provides a computer device, comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the multi-channel 4 GHz bandwidth radar radiation source signal generating method of the second aspect or any corresponding embodiment thereof by executing the computer instructions.

[0043] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the multi-channel 4 GHz bandwidth radar radiation source signal generating method of the second aspect or any corresponding embodiment thereof.

[0044] In a fifth aspect, the present invention provides a computer program product, comprising computer instructions, which are used to enable a computer to execute the multi-channel 4 GHz bandwidth radar radiation source signal generation method of the above-mentioned second aspect or any corresponding embodiment thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0046] Figure 1 is a signal generation principle diagram of a multi-channel 4 GHz bandwidth radar radiation source signal generation system according to an embodiment of the present invention;

[0047] Figure 2 4 is a hardware block diagram of a signal generation module of a multi-channel 4 GHz bandwidth radar radiation source signal generation system according to an embodiment of the present invention;

[0048] Figure 3 is a flow chart of a method for generating a multi-channel 4 GHz bandwidth radar radiation source signal according to an embodiment of the present invention;

[0049] Figure 4 is a flow chart of another method for generating multi-channel 4 GHz bandwidth radar radiation source signals according to an embodiment of the present invention;

[0050] Figure 5 It is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0052] Radar is widely used in transportation, air defense, anti-missile, collision avoidance, ocean surveillance and meteorological monitoring. Its radiation source signal simulation system is highly dependent on instantaneous bandwidth.

[0053] At the same time, during multi-channel radar simulation and antenna array testing, the amplitude and phase inconsistency between channels seriously affects the antenna performance, such as beam pointing deviation, broadening, sidelobe increase and gain reduction, thereby weakening the radar system performance and test accuracy.

[0054] According to an embodiment of the present invention, an embodiment of a multi-channel 4 GHz bandwidth radar radiation source signal generation system is provided, and the system includes:

[0055] A main control module, the main control module includes a COME board, the COME board is buckled on the signal generating module through a connector, the COME board is integrated with a PCIE interface, and is connected to the signal generating module through the PCIE interface. The main control module is used to control the signal generating module to generate a radar radiation source signal;

[0056] A signal generating module, comprising 2 FPGA chips, 2 ADC chips and 8 DAC chips, each FPGA chip being electrically connected to one ADC chip and four DAC chips;

[0057] A radio frequency module comprises one down-conversion channel, eight up-conversion channels and eight local oscillators; wherein each up-conversion channel is electrically connected to the DAC chip; the down-conversion channel is electrically connected to the ADC chip; the eight local oscillators are respectively connected to the eight up-conversion channels, and any one of the eight local oscillators is powered into eight paths, of which seven paths are respectively connected to the remaining seven local oscillators, and the remaining seven local oscillators all comprise single or double switches, and the single or double switches are used to switch local oscillator signals, so as to realize eight-channel independent local oscillators or common local oscillators, and the radio frequency module is used to transmit the radar radiation source signal.

[0058] Specifically, the RF module includes 1 down-conversion channel, 8 up-conversion channels and 8 local oscillators; each up-conversion channel is electrically connected to the DAC chip; the down-conversion channel is electrically connected to the ADC chip; the frequency synthesis unit includes 8 local oscillator modules, which provide local oscillator signals for the 8 frequency conversion channels respectively. The local oscillator module 1 is powered by 8 channels, 7 of which are connected to local oscillator modules 2 to 8 respectively. Local oscillator modules 2 to 8 all include single and double switches, which are used to switch their own local oscillator signals with the local oscillator signal of local oscillator module 1. Therefore, the 8 frequency conversion channels can realize common local oscillation or independent local oscillation. The RF module is used to transmit radar radiation source signals.

[0059] The RF module is also designed with a 2.4GHz±2GHz bandpass filter to filter out the image signal in the second Nyquist zone of the intermediate frequency.

[0060] For more information, please see Figure 1 The 8-channel radar radiation source signal generation system with a large instantaneous bandwidth includes a main control module, a signal generation module, and a radio frequency module. The main control module is integrated on the signal generation module and sends radar parameters (including signal pulse width, pulse repetition period, signal bandwidth, signal power, frequency agility type, etc.), control commands (including local oscillator mode, working mode, channel selection, start and stop commands, etc.), and radar baseband excitation data to the signal generation module through PCIE.

[0061] Among them, the signal generation module, such as Figure 2 As shown, it contains 2 large-scale high-performance FPGA chips with rich hardware resources such as BRAM, DSP Slices, I / O, GTY, etc. Each FPGA has an external ADC chip, 4 DAC chips and 4 groups of DDR4@4GB 2400MHz. Therefore, the board integrates 2 ADC chips, 8 DAC chips and 8 groups of DDR4. The 8 groups of DDR4 correspond to 8 channels, buffering radar baseband excitation data for playback. The 8 DACs have interpolation filtering and up-conversion functions, which can interpolate the baseband signal with a sampling rate of 4.8GSps by 2 times to 9.6GSps, filter, up-convert to 2.4GHz intermediate frequency, and then perform digital-to-analog conversion for output. One ADC can perform closed-loop acquisition for amplitude and phase consistency calibration.

[0062] In the clock design of the hardware card, in order to achieve phase consistency of the 8-channel signal, a LMX1204-1 clock chip is first used to receive the external 9.6GHz clock signal and the system reference signal of K7 in the board to achieve deterministic delay and multi-device synchronization, and fan out 3 9.6GHz clocks and system reference signals, which are connected to LMX1204-2, LMX1204-3 and LMX1204-4 respectively. LMX1204-2 fans out 2 9.6GHz clocks and system reference signals, which are connected to the corresponding 2 ADC chips respectively. LMX1204-3 and LMX1204-4 both fan out 4 9.6GHz clocks and system reference signals, which are connected to the CLK_P / N and SYSREF_P / N of the corresponding 4 DAC chips respectively. LMX1204-1 generates 2.4GHz clocks and system reference signals, which are connected to LMK04828. LMK04828 generates the ADC and DAC device clocks and reference signals required by the two FPGAs. LMK04828 generates high-speed port clocks required for 2-channel AD and 8-channel DA through ADCLK950 clock chip. During PCB Layout, ensure that the 9.6GHz clocks required for 8-channel DA, 8-channel reference signals, and high-speed port clocks of two FPGAs are of equal length. With equal-length wiring of clocks and reference signals and the same clock source, the 8-channel intermediate frequency signals have high phase consistency.

[0063] The signal generation module XC7K325T receives the system parameters, timing parameters, and radar parameters issued by the main control software through the PCIE register or DMA, and sends them to the high-performance FPGA through the SRIO interface. The timing parameters are sent to the timing generation module to generate a trigger pulse sequence (including fixed repetition rate, uneven repetition rate, jitter, slip repetition rate, and repetition rate pulse group). According to the excitation source in the system parameters, the radar radiation source baseband signal is generated in real time or the baseband signal in DDR4 is played back. The real-time generation mode adopts the DDS principle, and the frequency of the DDS output signal is controlled by the frequency control word to generate single carrier frequency, linear frequency modulation, or nonlinear frequency modulation signals. The playback mode receives the radar radiation source baseband data through DMA and stores the data in DDR4 for playback. Under the control of the trigger pulse sequence, each channel generates 4GHz bandwidth radar radiation source baseband data with 32 150MHz clocks (i.e., 4.8GSps sampling rate), performs flatness compensation and amplitude and phase calibration on the data, converts it into 16 300MHz clock data through FIFO, sends it to the DAC chip through the JESD204C interface, configures the DAC chip to perform 2x interpolation and filtering, sends the NCO control word to up-convert to 2.4GHz±2GHz intermediate frequency, and performs digital-to-analog conversion output at a sampling rate of 9.6GSps. At the same time, the baseband data after amplitude and phase compensation is uploaded to the host computer through PCIE in DMA mode for time-frequency domain monitoring.

[0064] In some optional implementations, the maximum sampling rates of the ADC chip and the DAC chip are not less than 10 GSps.

[0065] The embodiment of the present invention provides a multi-channel 4GHz bandwidth radar emitter signal generation method, which greatly improves the instantaneous signal bandwidth of the radar system by increasing the sampling rate, and realizes the multi-channel large bandwidth radar emitter signal generation system through the automated amplitude and phase calibration process. Rapid, full-band, full-dynamic range amplitude and phase consistency automatic calibration. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0066] Preferably, the system baseband sampling rate is 4.8GSps, and the maximum signal bandwidth of 4GHz can be collected. A single-channel 16-bit DAC chip is selected to output a 4GHz bandwidth signal with a 9.6GSps intermediate frequency sampling rate and a 2.4GHz center frequency.

[0067] In this embodiment, a multi-channel 4 GHz bandwidth radar radiation source signal generation method is provided, which is applied to the above radar radiation source signal generation system. Figure 3is a flow chart of a method for generating a radar radiation source signal according to an embodiment of the present invention. Figure 3 As shown, the process includes the following steps:

[0068] Step S101, obtaining radar baseband excitation data.

[0069] Specifically, the source of the radar baseband excitation data is determined, and the source includes but is not limited to a local storage device, an external interface, or a data stream generated in real time.

[0070] Furthermore, the main control module sends a data read request to the data source through the processor on the COME board, and sets the read parameters, such as the data start address, length, transmission rate, etc.

[0071] Further, the availability and integrity of data sources are checked to ensure that the data is correct and in a compatible format.

[0072] Step S102, multiplying the radar baseband excitation data by the corresponding amplitude and phase compensation coefficient to obtain target excitation data, so as to achieve amplitude and phase calibration of the radar baseband excitation signal.

[0073] Specifically, during the calibration phase, different amplitude and phase compensation coefficients corresponding to each power and frequency of each channel are determined by calculation. These coefficients need to be updated regularly due to factors such as hardware differences, environmental changes, or drift after long-term use.

[0074] Further, the radar baseband excitation data is multiplied by the amplitude and phase compensation coefficients.

[0075] Optionally, the calibrated target excitation data is preliminarily verified to check whether it meets the expected amplitude and phase characteristics. If the calibration effect does not meet the preset conditions, the compensation coefficient can be readjusted and the above calibration process can be repeated.

[0076] Optionally, the final determined amplitude and phase compensation coefficients and calibration results may be recorded in a system log or database for subsequent analysis and reference.

[0077] Step S103 , interpolating, filtering and performing a first mixing on the target excitation data in sequence to obtain an intermediate frequency signal with a preset sampling rate.

[0078] Specifically, the interpolation process is to increase the sampling rate of the target excitation data and provide sufficient data points for subsequent filtering and mixing so as to match the sampling rate requirements of subsequent steps. Specifically, the interpolation is 2 times.

[0079] Further, filtering is used to remove high-frequency noise or unwanted signal components that may be introduced during the interpolation process, while retaining the key features of the target signal. The interpolated data is filtered so that the filtered data will be smoother and meet the requirements of subsequent processing steps.

[0080] Furthermore, the first mixing process up-converts the filtered target excitation data from a baseband signal to an intermediate frequency signal to meet the transmission requirements of the radio frequency module.

[0081] Step S104, performing a second mixing on the intermediate frequency signal and amplifying it to a preset power to generate a 4 GHz bandwidth radar radiation source signal.

[0082] Specifically, the transmitting channel of the RF module mixes the received 2.4GHz intermediate frequency signal with a 24.4GHz fixed local oscillator, converts the frequency to 22GHz, amplifies and filters the signal, and then mixes it with a local oscillator of 22.3GHz~40GHz to obtain a RF signal of 0.3GHz~18GHz, which is output after amplitude control and power amplification.

[0083] The multi-channel 4GHz bandwidth radar radiation source signal generation method provided in this embodiment obtains the radar baseband excitation signal, calibrates the amplitude and phase consistency of the radar excitation data, performs 2x interpolation, filtering, and up-conversion to a 9.6GSps sampling rate and 2.4GHz±2GHz intermediate frequency signal through the DAC chip, and outputs it to the RF module after digital-to-analog conversion. The amplitude and phase calibrated data is sent to the main control module through the DMA mode of PCIE for time domain waveform display and frequency domain spectrum display. The transmitting channel of the RF module mixes the received 2.4GHz signal with the 24.4GHz fixed local oscillator first, converts the frequency to 22GHz, amplifies and filters the signal, and then mixes it with the local oscillator 22.3GHz~40GHz to obtain a RF 0.3GHz~18GHz signal, which is output after amplitude control and power amplification. The system baseband sampling rate is designed to be 4.8GSps, so it can collect signals with a maximum bandwidth of 4GHz. By increasing the sampling rate, the instantaneous signal bandwidth of the radar system can be greatly improved. Through the automated amplitude and phase calibration process, the 8-channel 4GHz bandwidth radar radiation source signal generation system can be quickly and fully calibrated for amplitude and phase consistency across the entire frequency band and full dynamic range.

[0084] In some optional implementations, the radar baseband excitation data is pre-generated playback data or real-time data; when the radar baseband excitation data is pre-generated playback data, obtaining the radar baseband excitation data includes:

[0085] Generate a trigger pulse sequence according to radar parameters;

[0086] Based on the trigger pulse sequence, the radar baseband excitation data stored in the double data rate synchronous dynamic random access memory is read.

[0087] Please refer to Figure 4When the radar baseband excitation data is pre-generated playback data, the radar parameters configured by the user are received, the MATLAB DLL library is called to generate radar radiation source waveform data and saved to a file, and the data in the waveform file is sent to the signal generation module through DMA (Direct Memory Access) and then stored in DDR4 (Double Data Rate 4th Generation, fourth generation double data rate synchronous dynamic random access memory). Then, the system parameters are sent to the signal generation module through registers or DMA, and the amplitude and phase compensation coefficients in the main control software database are indexed according to the frequency and power values, and sent to the signal generation module through DMA. The start instruction is sent to the signal generation module through the PCIE register, and a trigger pulse sequence is generated according to the timing parameters. According to the trigger pulse sequence, the radar radiation source baseband data in DDR4 is read at a sampling rate of 4.8GSps.

[0088] When the radar baseband excitation data is data generated in real time by FPGA using DDS, the system parameters, timing parameters, and radar parameters configured by the user are received, and the parameters are sent to the signal generation module through registers or DMA, and the amplitude and phase compensation coefficients in the database are indexed according to the frequency and power values, and sent to the signal generation module through DMA, and the start instruction is sent to the signal generation module through the PCIE register, and a trigger pulse sequence is generated according to the timing parameters, and the radar radiation source baseband signal is generated using the DDS principle.

[0089] Multiply the radar baseband excitation data with the corresponding amplitude and phase compensation coefficients to obtain the target radar baseband excitation data, including:

[0090] The target amplitude and phase compensation coefficients are obtained by indexing the compensation coefficient database based on the frequency and power of the radar baseband excitation data; the compensation coefficient database is used to indicate the mapping relationship between the frequency and power and the amplitude and phase compensation coefficients;

[0091] Multiply the radar baseband excitation data with the corresponding amplitude and phase compensation coefficients to obtain the target excitation data.

[0092] First, a compensation coefficient database is established, which stores the corresponding amplitude and phase compensation coefficients under different frequencies and powers. Therefore, the database should contain frequency, power and corresponding amplitude and phase compensation coefficient fields for fast indexing and searching. These compensation coefficients are obtained through simulation calculations and are used to correct the amplitude and phase errors that may be generated during the transmission of radar baseband excitation data. The mapping relationship in the database can be discrete or continuous. When the radar baseband excitation data is generated, it is indexed in the compensation coefficient database according to its frequency and power information to find the amplitude and phase compensation coefficient corresponding to the target radar baseband excitation data, and the amplitude and phase compensation coefficient found is multiplied with the radar baseband excitation data to achieve comprehensive correction of the radar baseband excitation data.

[0093] In some optional implementations, multiplying the radar baseband excitation data by the corresponding amplitude and phase compensation coefficients to obtain the target excitation data includes:

[0094] For the radar baseband excitation data, within the preset frequency and power range, the preset frequency and power step length is used for stepping, and multiple sets of adjusted radar excitation baseband data corresponding to each step length are collected;

[0095] Upload multiple sets of adjusted radar baseband data to the preset software for analysis to obtain single pulse signals corresponding to various frequencies and powers;

[0096] Calculate the corresponding real-time amplitude and phase compensation coefficient based on a single pulse signal;

[0097] The compensation coefficient database is updated based on the real-time amplitude and phase compensation coefficients.

[0098] In the traditional calibration scheme, it is impossible to select a specific range of radar baseband excitation data, nor is it possible to adjust the frequency and power step size in a targeted manner. Therefore, the flexibility of the calibration scheme is poor. In this embodiment, the calibration range and step size can be flexibly adjusted. First, the preset frequency and power range of the radar baseband excitation data, as well as the preset frequency and power step size, are determined. Within the preset frequency and power range, each pulse is stepped through with a preset step size. Each pulse adjusts the frequency and power of the radar baseband excitation data with a preset step size, and collects the adjusted radar baseband data. The collected multiple groups of adjusted radar baseband data are uploaded to the preset software for analysis to extract the single pulse signals corresponding to each frequency and power. Based on the extracted single pulse signal, the corresponding real-time amplitude and phase compensation coefficient is calculated, and the database should be regularly updated based on the latest real-time amplitude and phase compensation coefficient to ensure the real-time performance of the compensation coefficient database.

[0099] In some optional implementations, if the single pulse signal is a single-point frequency signal, the corresponding real-time amplitude-phase compensation coefficient is calculated based on the single pulse signal, including:

[0100] Based on the frequency and power of the single-point frequency signal, acquiring a reference signal corresponding to the single-point frequency signal;

[0101] The single-point frequency signal and the reference signal are respectively subjected to fast Fourier transformation, the maximum value of the two signals in the frequency domain is taken to obtain the amplitude difference, the phase of the two signals is obtained to obtain the phase difference, and thus the real-time amplitude-phase compensation coefficient is obtained.

[0102] The reference signal is S0, and the signal corresponding to the kth power of the jth frequency point of the i-th channel is S i,j,k , then taking the amplitude and phase of the reference signal as reference, the calculation formula for the amplitude and phase compensation coefficient corresponding to the kth power of the jth frequency point of the ith channel is:

[0103]

[0104] Where c i,j,k is the channel amplitude and phase compensation coefficient. In the digital baseband, a complex multiplier is used to implement the compensation. When performing complex multiplication, the digital processing bit width used is 16 bits for I and Q data respectively. The amplitude range of 16-bit signed data is 0 to 32767, the minimum signal change is 1, and the minimum signal amplitude adjustment dB is:

[0105] 20×log 10 (32767 / 32766) = 2.7e -4 dB

[0106] When the signal amplitude is small, the dB value corresponding to the minimum amplitude change is large. For example, when the signal amplitude is 63, the dB value corresponding to the signal amplitude change of 1 is:

[0107] 20×log 10 (63 / 62) = 0.139 dB

[0108] The required channel amplitude consistency is ±0.5dB. Therefore, when the baseband signal is generated, its digital amplitude is kept large, and the channel amplitude can be compensated in fine steps to meet the amplitude consistency ≤±0.5dB indicator.

[0109] When the data uses a 16-bit width, the minimum angular interval that can be represented is:

[0110]

[0111] This minimum angle step interval can be used for phase compensation to meet the phase consistency ≤±2.5° indicator.

[0112] In some optional implementations, if the single pulse signal is a bandwidth signal, the corresponding real-time amplitude and phase compensation coefficient is calculated based on the single pulse signal, including:

[0113] Constructing an amplitude-phase compensation filter, wherein the order of the amplitude-phase compensation filter is a preset value;

[0114] Constructing a matrix based on the radar baseband excitation data; the number of columns of the matrix is ​​the order of the amplitude-phase compensation filter;

[0115] Based on the least square method, the coefficients of the amplitude-phase compensation filter are obtained.

[0116] For broadband signals, the least square method is used for time domain fitting to design an amplitude-phase compensation filter. The order of the designed amplitude-phase compensation filter is P. Considering the filter response, the head and tail P / 2 are invalid responses, and the number of fitted data points is N = Nd-P, where Nd is the number of points of the ideal signal.

[0117] The collected non-ideal signal y(n) is used to calculate the amplitude and phase compensation filter coefficient c(P). The ideal signal x(n) should be obtained by filtering y(n), that is, the requirement is:

[0118]

[0119] In the above formula, y(n) is the measured radar baseband excitation data, and x(n) is the ideal signal constructed based on the parameters, both of which are known quantities. The above formula is a linear equation system, and c(n) can be obtained by solving the linear equation system.

[0120] The convolution expression is:

[0121]

[0122] Right now:

[0123] x(1)=y(P)·c(0)+y(P-1)·c(1)+y(P-2)·c(2)+…+y(1)·c(P)

[0124] x(2)=y(P+1)·c(0)+y(P)·c(1)+y(P-1)·c(2)+…+y(2)·c(P)

[0125] x(3)=y(P+2)·c(0)+y(P+1)·c(1)+y(P)·c(2)+…+y(3)·c(P)

[0126] ……………………………………………………………………………………

[0127] ……………………………………………………………………………………

[0128] x(N)=y(P-1+N)·c(0)+y(P-2+N)·c(1)+y(P-3+N)·c(2)+…+y(N)·c(P)

[0129] It can be seen that the above equation is a system of simultaneous linear equations about the variable c(n). Written in matrix form, it is:

[0130]

[0131] Using vector and matrix notation, the above equation can be written as:

[0132] x=Y·c

[0133] Where x is the column vector of the ideal bandwidth signal sampling points, Y is the matrix of the measured signal sampling points, and c is the amplitude and phase compensation coefficient vector to be solved. All quantities in the above formula are complex numbers.

[0134] Multiplying x by the inverse of matrix Y gives c, that is:

[0135] c=Y -1 ·x

[0136] The number of columns of matrix Y is the order of the amplitude-phase compensation filter, and the number of rows is the signal length minus the filter order. The number of rows of the matrix is ​​much greater than the number of columns. Since only square matrices have inverses, the formula is optimized to minimize the error between x and Y·c. The optimized equation is expressed as follows:

[0137] c=(Y H Y) -1 Y H x

[0138] The calculation process expressed in the above formula is as follows:

[0139] 1) Take the conjugate transpose of matrix Y to get Y H ;

[0140] 2) Y H Multiply it with the Y matrix and then invert it;

[0141] 3) Find the inverse result and multiply it by matrix Y H ;

[0142] 4) Finally, multiply it by vector x to get c.

[0143] The calculation method of amplitude and phase compensation is:

[0144] The matrix y(n) formed by the measured radar baseband excitation data is matrix-multiplied with the amplitude-phase compensation filter coefficient c(P) to obtain the compensated target excitation data y′(n), as shown in the following formula:

[0145]

[0146] The embodiment of the present invention also provides a computer device, see Figure 5 , Figure 5 is a schematic diagram of the structure of a computer device provided by an optional embodiment of the present invention, such as Figure 5 As shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components are connected to each other using different buses for communication, and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 5 A processor 10 is taken as an example.

[0147] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0148] The memory 20 stores instructions executable by at least one processor 10, so that at least one processor 10 executes the method shown in the above embodiment.

[0149] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0150] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 20 may also include a combination of the above types of memory.

[0151] The computer device also includes an input device 30 and an output device 40. The processor 10, the memory 20, the input device 30 and the output device 40 may be connected via a bus or other means. Figure 5 The example of connecting through bus is taken in the following.

[0152] The input device 30 can receive input digital or character information, and generate key signal input related to the user settings and function control of the computer device, such as a touch screen, a keypad, a mouse, a track pad, a touch pad, an indicator bar, one or more mouse buttons, a trackball, a joystick, etc. The output device 40 may include a display device, an auxiliary lighting device (e.g., an LED) and a tactile feedback device (e.g., a vibration motor), etc. The above-mentioned display device includes but is not limited to a liquid crystal display, a light emitting diode, a display and a plasma display. In some optional embodiments, the display device can be a touch screen.

[0153] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0154] A part of the present invention may be applied as a computer program product, such as a computer program instruction, which, when executed by a computer, can call or provide the method and / or technical solution according to the present invention through the operation of the computer. Those skilled in the art should understand that the existence of the computer program instruction in a computer-readable medium includes, but is not limited to, a source file, an executable file, an installation package file, etc., and accordingly, the way in which the computer program instruction is executed by the computer includes, but is not limited to: the computer directly executes the instruction, or the computer compiles the instruction and then executes the corresponding compiled program, or the computer reads and executes the instruction, or the computer reads and installs the instruction and then executes the corresponding installed program. Here, the computer-readable medium may be any available computer-readable storage medium or communication medium accessible to the computer.

[0155] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A 4 GHz bandwidth radar radiation source signal generation system, characterized in that: The system comprises: A main control module, wherein the main control module comprises a COME board, wherein the COME board is buckled on the signal generating module through a connector, wherein a PCIE interface is integrated on the COME board, and the signal generating module is connected through the PCIE interface, wherein the main control module is used to control the signal generating module to generate a radar radiation source signal; The signal generating module comprises 2 FPGA chips, 2 ADC chips and 8 DAC chips, and each of the FPGA chips is electrically connected to one ADC chip and four DAC chips; A radio frequency module comprises one down-conversion channel, eight up-conversion channels and eight local oscillators; wherein each up-conversion channel is electrically connected to the DAC chip; the down-conversion channel is electrically connected to the ADC chip; the eight local oscillators are respectively connected to the eight up-conversion channels, and any one of the eight local oscillators is powered into eight paths, of which seven paths are respectively connected to the remaining seven local oscillators, and the remaining seven local oscillators all comprise single and double switches, and the single and double switches are used to switch local oscillator signals, so as to realize eight-channel independent local oscillators or common local oscillators, and the radio frequency module is used to transmit the radar radiation source signal.

2. The system according to claim 1, characterized in that The maximum sampling rates of the ADC chip and the DAC chip are no less than 10 GSps.

3. A method for generating a 4 GHz bandwidth radar radiation source signal, characterized in that: Applied to the system of claim 1 or 2, the method comprises: Obtain radar baseband excitation data; Multiplying the radar baseband excitation data by the corresponding amplitude and phase compensation coefficient to obtain target excitation data, so as to achieve amplitude and phase calibration of the radar baseband excitation signal; The target excitation data is sequentially interpolated, filtered, and subjected to a first mixing to obtain an intermediate frequency signal of a preset sampling rate; The intermediate frequency signal is subjected to a second mixing and amplified to a preset power to generate a 4 GHz bandwidth radar radiation source signal.

4. The method according to claim 3, characterized in that The radar baseband excitation data is pre-generated playback data or real-time data; When the radar baseband excitation data is pre-generated playback data, the obtaining of the radar baseband excitation data includes: Generate a trigger pulse sequence according to radar parameters; Based on the trigger pulse sequence, the radar baseband excitation data stored in the double data rate synchronous dynamic random access memory is read.

5. The method according to claim 4, characterized in that The step of multiplying the radar baseband excitation data by the corresponding amplitude and phase compensation coefficient to obtain the target radar baseband excitation data includes: Based on the frequency and power of the radar baseband excitation data, the target amplitude and phase compensation coefficients are obtained by indexing in the compensation coefficient database; the compensation coefficient database is used to indicate the mapping relationship between the frequency and power and the amplitude and phase compensation coefficients; The radar baseband excitation data is multiplied by the corresponding amplitude and phase compensation coefficient to obtain target excitation data.

6. The method according to claim 5, characterized in that The step of multiplying the radar baseband excitation data by the corresponding amplitude and phase compensation coefficient to obtain target excitation data includes: The radar baseband excitation data is stepped through with a preset frequency and power step length within a preset frequency and power range, and a plurality of groups of adjusted radar excitation baseband data corresponding to each step length are collected; Uploading multiple groups of adjusted radar baseband data to preset software for analysis to obtain single pulse signals corresponding to various frequencies and powers; Calculate the corresponding real-time amplitude and phase compensation coefficient based on the single pulse signal; The compensation coefficient database is updated based on the real-time amplitude and phase compensation coefficients.

7. The method according to claim 6, characterized in that If the single pulse signal is a single-point frequency signal, the step of calculating the corresponding real-time amplitude-phase compensation coefficient based on the single pulse signal includes: Based on the frequency and power of the single-point frequency signal, acquiring a reference signal corresponding to the single-point frequency signal; The single-point frequency signal and the reference signal are respectively subjected to fast Fourier transform to obtain the real-time amplitude-phase compensation coefficient.

8. The method according to claim 7, characterized in that If the single pulse signal is a bandwidth signal, the step of calculating the corresponding real-time amplitude and phase compensation coefficient based on the single pulse signal includes: Constructing an amplitude-phase compensation filter, wherein the order of the amplitude-phase compensation filter is a preset value; Constructing a matrix based on the radar baseband excitation data; the number of columns of the matrix is ​​the order of the amplitude-phase compensation filter; Based on the least square method, the coefficients of the amplitude-phase compensation filter are obtained.

9. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the 4 GHz bandwidth radar radiation source signal generation method according to any one of claims 3 to 8 by executing the computer instructions.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the 4 GHz bandwidth radar radiation source signal generation method according to any one of claims 3 to 8.

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