CN115085842A - RF signal acquisition, recording and playback system - Google Patents

Abstract

The invention relates to the technical field of signal processing, and provides a radio frequency signal acquisition, recording and playback system, which comprises a down converter, an intermediate frequency signal recording unit and an up converter, wherein the down converter is used for receiving radio frequency signals and converting the radio frequency signals into intermediate frequency signals; the intermediate frequency signal recording unit is used for receiving the intermediate frequency signal, converting the intermediate frequency signal into a digital intermediate frequency signal and storing the digital intermediate frequency signal in the solid-state disk array; and the up-converter is used for receiving the intermediate frequency signals played back from the solid-state disk array by the intermediate frequency signal recording unit and converting the intermediate frequency signals into radio frequency signals. According to the radio frequency signal acquisition, recording and playback system, information interaction among the down converter, the intermediate frequency signal recording unit and the up converter is constructed, so that an internal field test task of communication countermeasure can be guaranteed, and the simulation test capability is improved; the system can collect signal samples in real time, can return communication signals to the air to be used as real-time test signals, and has the capability of viewing, monitoring and displaying frequency spectrums.

Description

RF signal acquisition, recording and playback system

technical field

The invention relates to the technical field of signal processing, in particular to a radio frequency signal acquisition, recording and playback system.

Background technique

In the fields of radar, aerospace, communication, electronic warfare, etc., on-site signals play an important role. These signals have the characteristics of strong real-time performance, high data rate, large amount of data, and complex processing. Therefore, the acquisition of signals plays a pivotal role, and it can build various semi-physical simulations and physical systems. Once the information can be collected, stored and played back, it provides original real data for various experiments, which greatly shortens the development cycle and reduces research costs.

In the above fields, it is often necessary to collect, analyze and play back radio frequency signals in the air. Depending on the application, sometimes it is necessary to record the signals for a long time. The signal acquisition time ranges from microseconds to milliseconds to seconds or even hours. Therefore, it is of great practical significance to have a high-speed signal real-time monitoring, acquisition, and storage system in a complex electromagnetic environment. At present, there is no relatively complete and good equipment for signal acquisition, recording and playback.

SUMMARY OF THE INVENTION

In view of the problems existing in the prior art, the present invention provides a radio frequency signal acquisition, recording and playback system.

The invention provides a radio frequency signal acquisition, recording and playback system, comprising a downconverter, an intermediate frequency signal recording unit and an upconverter, wherein:

a downconverter for receiving radio frequency signals and converting the radio frequency signals into intermediate frequency signals;

an intermediate frequency signal recording unit, configured to receive the intermediate frequency signal, convert the intermediate frequency signal into a digital intermediate frequency signal, and store the digital intermediate frequency signal in a solid-state disk array;

The up-converter is used for receiving the intermediate frequency signal played back from the solid-state disk array by the intermediate frequency signal recording unit, and converting the intermediate frequency signal into a radio frequency signal.

In one embodiment, the intermediate frequency signal recording unit includes a data acquisition unit, an intermediate frequency processing unit, a main control unit, a data storage unit and a data playback unit, wherein:

The data acquisition unit is used to perform A/D conversion on the intermediate frequency signal to obtain a digital intermediate frequency signal;

The intermediate frequency processing unit is used to analyze the signal spectrum of the digital intermediate frequency signal, obtain the monitoring spectrum data, and report the monitoring spectrum data to the main control unit; and determine and collect the digital intermediate frequency signal corresponding to the target frequency point according to the monitoring spectrum data;

The main control unit is used to display the monitoring spectrum data, and convert the digital intermediate frequency signal corresponding to the target frequency point into a data file, which is stored in the solid-state disk array by the data storage unit;

The data playback unit is used to perform D/A conversion on the digital intermediate frequency signal corresponding to the target frequency point to obtain the intermediate frequency signal, and the intermediate frequency signal is converted into a radio frequency signal by the up-converter.

In one embodiment, the intermediate frequency processing unit is specifically configured to: perform signal spectrum analysis on the digital intermediate frequency signal according to preset monitoring parameters, select a baseband digital signal with a preset sampling rate according to the spectrum bandwidth and resolution requirements, and perform FFT and Calculate the power spectrum to obtain the monitoring spectrum data.

In one embodiment, the downconverter includes a first amplifier, a prefilter, a first mixer, a first filter, a second amplifier, a second mixer, a second filter, a third amplifier , a gainer, and a fourth amplifier, where:

The input end of the first amplifier is connected to the radio frequency signal, the output end of the first amplifier is connected to the input end of the pre-filter, the output end of the pre-filter is connected to the first input end of the first mixer, and the output end of the first mixer is connected to the first input end of the first mixer. The second input terminal is connected to the first local oscillator signal, the output terminal of the first mixer is connected to the input terminal of the first filter, the output terminal of the first filter is connected to the input terminal of the second amplifier, and the output terminal of the second amplifier is connected to The first input end of the second mixer, the second input end of the second mixer is connected to the second local oscillator signal, the output end of the second mixer is connected to the input end of the second filter, the second filter The output end is connected to the input end of the third amplifier, the output end of the third amplifier is connected to the input end of the gainer, the output end of the gainer is connected to the input end of the fourth amplifier, and the output end of the fourth amplifier is connected to the data acquisition unit.

In one embodiment, the intermediate frequency processing unit includes an N-order anti-aliasing filtering device, wherein:

The N-order anti-aliasing filtering device is used to determine the digital intermediate frequency signal corresponding to the target frequency point according to the monitoring spectrum data after the order is determined according to the preset effective signal bandwidth and sampling rate, and perform anti-aliasing on the digital intermediate frequency signal corresponding to the target frequency point. Aliasing filter processing, output the IQ digital signal to be sampled.

In one embodiment, the anti-aliasing filtering device of each order includes a forward filtering unit and a reverse filtering unit, the forward filtering unit includes a forward mixer and a third filter, and the reverse filtering unit Includes inverse mixer and fourth filter.

In one embodiment, the main control unit is further configured to: determine whether the digital intermediate frequency signal corresponding to the target frequency point satisfies the signal storage warning condition, and if so, issue a warning message.

In an embodiment, the main control unit is specifically configured to: generate a graphical file based on the monitored spectrum data, and display the graphical file.

In an embodiment, the up-converter is specifically used to: adjust the center frequency to play back the intermediate frequency signal, obtain the radio frequency signal, and output the radio frequency signal.

In one embodiment, the data acquisition unit and the data playback unit respectively use an FPGA mezzanine card high-speed ADC module and an FPGA mezzanine card high-speed DAC module.

The radio frequency signal acquisition, recording and playback system provided by the invention can ensure the communication against the infield test task and improve the simulation test ability by constructing the information exchange among the downconverter, the intermediate frequency signal recording unit and the upconverter; it can collect signal samples in real time. , the communication signal can be played back to the air as a real-time test signal, and it has the ability to view, monitor and display the spectrum.

Description of drawings

In order to explain the present invention or the technical solutions in the prior art more clearly, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are the For some embodiments of the invention, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without any creative effort.

1 is a schematic structural diagram of a radio frequency signal acquisition, recording and playback system provided by the present invention;

2 is a schematic diagram of a frame of a radio frequency signal acquisition, recording and playback system provided by the present invention;

3 is a schematic structural diagram of a downconverter provided by the present invention;

4 is a schematic structural diagram of an analog-to-digital converter and a first-order anti-aliasing filtering device provided by the present invention;

FIG. 5 is a schematic diagram of the data flow of the multi-order anti-aliasing filtering device provided by the present invention during the filtering process.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention. , not all examples. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The radio frequency signal acquisition, recording and playback system of the present invention is described below with reference to FIGS. 1 to 5, including a downconverter 11, an intermediate frequency signal recording unit 12 and an upconverter 13, wherein:

The downconverter 11 is used for receiving radio frequency signals and converting the radio frequency signals into intermediate frequency signals;

The intermediate frequency signal recording unit 12 is used to receive the intermediate frequency signal, convert the intermediate frequency signal into a digital intermediate frequency signal, and store the digital intermediate frequency signal in the solid-state disk array;

The up-converter 13 is used for receiving the intermediate frequency signal played back from the solid-state disk array by the intermediate frequency signal recording unit, and converting the intermediate frequency signal into a radio frequency signal.

In this regard, it should be noted that, in the present invention, the radio frequency signal acquisition, recording and playback system is mainly used to ensure the communication countermeasure infield test task and improve the simulation test ability; it can collect signal samples in real time, and can play back the communication signal into the air as a Test signals in real time with spectrum viewing, monitoring and display capabilities.

The radio frequency signal acquisition, recording and playback system as a whole includes a downconverter, an intermediate frequency signal recording unit and an upconverter. The downconverter converts the radio frequency signal (1MHz to 6.6GHz) to the intermediate frequency signal, and can adjust the power. The intermediate frequency signal recording unit performs digital processing on the intermediate frequency signal and converts it into a digital intermediate frequency signal, and stores the digital intermediate frequency signal in the local solid-state disk array in the form of a data file. The up-converter converts the intermediate frequency signal played back from the intermediate frequency signal recording unit into a radio frequency signal (1MHz～6.6GHz) for output.

In the present invention, the up-converter adjusts the center frequency to play back the intermediate frequency signal, obtains the radio frequency signal, and outputs the radio frequency signal. In addition, the signal is initially analyzed based on the playback display. During the analysis process, the position of the analysis file, pause and other operations can be selected at will, and data segmentation and data format conversion can be performed.

In the present invention, the radio frequency signal acquisition, recording and playback system adopts the software radio architecture design idea, and the system is designed as a communication signal receiving and storage platform with wide frequency band, strong signal processing capability, good versatility and expansibility. The equipment consists of three parts: high-performance hardware platform, standardized software platform and high-speed acquisition, storage and playback software application platform. Referring to Figure 2, Figure 2 shows a system architecture block diagram. Here, the high-performance hardware platform is equivalent to the hardware components of the system, mainly including: downconverter, intermediate frequency signal recording unit and upconverter. The intermediate frequency signal recording unit 12 includes a data acquisition unit 121 , an intermediate frequency processing unit 122 , a main control unit 123 , a data storage unit 124 and a data playback unit 125 .

The data acquisition unit 121 is used to perform A/D conversion on the intermediate frequency signal to obtain a digital intermediate frequency signal;

The intermediate frequency processing unit 122 is used to perform signal spectrum analysis on the digital intermediate frequency signal, obtain monitoring spectrum data, and report the monitoring spectrum data to the main control unit; and determine and collect the digital intermediate frequency signal corresponding to the target frequency point according to the monitoring spectrum data;

The main control unit 123 is used to display the monitoring spectrum data, and convert the digital intermediate frequency signal corresponding to the target frequency point into a data file, which is stored in the solid-state disk array by the data storage unit 124;

The data playback unit 125 is configured to perform D/A conversion on the digital intermediate frequency signal corresponding to the target frequency point to obtain an intermediate frequency signal, and the intermediate frequency signal is converted into a radio frequency signal by an up-converter.

It should be noted that the downconverter is responsible for mixing the micro-signal RF carrier to the intermediate frequency signal after filtering based on the pre-amplifier, and the data acquisition unit converts the intermediate frequency signal signal into a digital intermediate frequency signal after gain and sends it to the intermediate frequency acquisition and processing unit. .

After the IF processing unit performs waveform synthesis, digital down-conversion, baseband waveform processing, etc. on the digital IF signal, it realizes signal spectrum analysis, obtains monitoring spectrum data, and reports the monitoring spectrum data to the main control unit; and determines the target frequency according to the monitoring spectrum data. The digital intermediate frequency signal corresponding to the point is collected, and the target frequency point can be a time point or a time period. The present invention can perform selective data acquisition for digital intermediate frequency signals.

The CPU main control unit realizes the man-machine interface for operation and control. The monitoring spectrum data is displayed, and the digital intermediate frequency signal corresponding to the target frequency point is converted into a data file, and the data storage unit is responsible for recording the collected digital intermediate frequency signal on the hardware array in real time by means of a RAID array.

The data playback unit performs D/A conversion on the digital intermediate frequency signal corresponding to the target frequency point to obtain the intermediate frequency signal, and the intermediate frequency signal is converted into a radio frequency signal by the up-converter.

Further explanation, the data acquisition unit and the data playback unit are composed of two boards: one is the FPGA Mezzanine Card (FMC) high-speed ADC module (as a data acquisition unit), which can support a single-channel sampling rate of up to 240MSps ; The second is the FPGA Mezzanine Card (FPGA Mezzanine Card, that is, FMC) high-speed DAC module (as a data playback unit), which can support a single-channel sampling rate of up to 240MSps. When in use, the two boards are installed through high-speed connectors.

For further explanation, the intermediate frequency processing unit performs signal spectrum analysis on the digital intermediate frequency signal according to the preset monitoring parameters, selects the baseband digital signal with the preset sampling rate according to the spectrum bandwidth and resolution requirements, performs FFT and power spectrum calculation, and obtains monitoring spectrum data. . It should be noted that the intermediate frequency processing unit can monitor the signals in the specified frequency band and the specified bandwidth in real time, and monitor the characteristics of the wireless signal through spectrum information. The equipment performs time-frequency domain conversion calculation based on discrete Fourier transform (FFT) on the signal in the monitoring frequency band, and obtains the power spectrum information of the signal in the real-time bandwidth.

In addition, the main control unit generates a graphical file based on the monitoring spectrum data, and displays the graphical file. Specifically, the conventional spectrogram, two-dimensional and three-dimensional waterfall chart can be displayed in a graphical display mode, and the frequency domain information of the signal can be statistically displayed afterglow according to the requirements, and then the frequency domain characteristics of the signal can be analyzed from multiple dimensions. Visual display. The signal spectrogram is a two-dimensional display of the frequency point and its corresponding energy information at a certain moment of the signal, and the frequency of the general display is 25 to 40 frames per second; Energy information is displayed.

Each component of the high-performance hardware platform is relatively independent, and the interaction adopts a standard interface, which is convenient for the development and upgrade of functional independent components. Select mature boards with high-performance CPU and FPGA and other processors as the core, and perform data interaction based on high-speed PCI-E bus. In order to facilitate parallel data processing in the future, the motherboard has a spare PCI-E interface for future expansion of GPU boards; the selection of high-speed data bus and board chip not only meets the requirements of current communication signal simulation equipment, but also can meet the Meet future functional expansion and performance upgrade requirements to maximize the hardware life cycle.

The standardized software platform consists of operating system, hardware abstraction layer, transmission mechanism layer (hardware abstraction layer and middleware), core framework layer, etc. It provides services such as PCIE bus, software middleware and hardware abstraction, and realizes high-speed data acquisition and storage software applications The loose coupling with the underlying general hardware platform provides convenient conditions for application development and application portability, and supports dynamic reconstruction of waveform simulation and transmission functions.

The high-speed acquisition, storage and playback software application platform includes signal monitoring software, signal acquisition and storage software and signal playback software. Each software processes and displays the communication or radar echo signals received by the system in time and frequency domains. The processing of waveform data can be based on MATLAB, C or C++, and the signal can be displayed as waveform display, FFT transformation, waterfall chart display, persistence display, etc. Under the application software platform, software files in various formats can be generated, and data processing can be performed using the provided various algorithm libraries in matlab and C++.

In the further explanation of the above system, referring to FIG. 3, the downconverter 11 includes a first amplifier 111, a pre-filter 112, a first mixer 113, a first filter 114, a second amplifier 115, a second mixer 116, second filter 117, third amplifier 118, gainer 119 and fourth amplifier 120, wherein:

The input end of the first amplifier is connected to the radio frequency signal, the output end of the first amplifier is connected to the input end of the pre-filter, the output end of the pre-filter is connected to the first input end of the first mixer, and the output end of the first mixer is connected to the first input end of the first mixer. The second input terminal is connected to the first local oscillator signal, the output terminal of the first mixer is connected to the input terminal of the first filter, the output terminal of the first filter is connected to the input terminal of the second amplifier, and the output terminal of the second amplifier is connected to The first input end of the second mixer, the second input end of the second mixer is connected to the second local oscillator signal, the output end of the second mixer is connected to the input end of the second filter, the second filter The output end is connected to the input end of the third amplifier, the output end of the third amplifier is connected to the input end of the gainer, the output end of the gainer is connected to the input end of the fourth amplifier, and the output end of the fourth amplifier is connected to the data acquisition unit.

The down-converter has undergone two frequency conversions, and both frequency conversions use high local oscillator signals, so the frequency spectrum is not inverted after frequency conversion. The input RF signal first goes through a low noise amplifier to reduce the noise figure of the inverter. Then the signal is mixed with the first local oscillator 8.4-13.9GHz after passing through the pre-filter to obtain the first IF signal of 7.9GHz, which is filtered and amplified and mixed with the second local oscillator 8.62GHz to obtain the first IF signal The second intermediate frequency signal is 720MHz, and the second intermediate frequency signal is output after filtering, amplifying, and gain control.

In the further explanation of the above system, the intermediate frequency processing unit includes an N-order anti-aliasing filtering device, wherein:

The N-order anti-aliasing filtering device is used to determine the digital intermediate frequency signal corresponding to the target frequency point according to the monitoring spectrum data after the order is determined according to the preset effective signal bandwidth and sampling rate, and perform anti-aliasing on the digital intermediate frequency signal corresponding to the target frequency point. Aliasing filter processing, output the IQ digital signal to be sampled.

In the present invention, the N-order anti-aliasing filtering device can be adapted to the filtering device with multi-order anti-aliasing function. According to the order t, a filter device with t-order anti-aliasing function is arranged, and the received IF digital signal is subjected to anti-aliasing filtering processing by means of the determined filter device, and the IQ digital signal to be sampled is output. The output IQ digital signal to be sampled is performing subsequent sampling work.

Further explanation, the anti-aliasing filtering device of each order includes a forward filtering unit and a reverse filtering unit, the forward filtering unit includes a forward mixer and a first filter, and the reverse filtering unit includes Inverse mixer and second filter.

Referring to FIG. 4 and FIG. 5 , FIG. 4 is a schematic structural diagram of an analog-to-digital converter and a first-order anti-aliasing filtering device, and FIG. 5 is a schematic diagram of data flow of the multi-order anti-aliasing filtering device during the filtering process.

It can be seen in FIG. 4 that the anti-aliasing filtering device of each order includes a forward filtering unit and a reverse filtering unit, the forward filtering unit includes a forward mixer 41 and a third filter 42, and the reverse filtering unit An inverse mixer 43 and a fourth filter 44 are included. As can be seen in Figure 5, when the signal sampling frequency is Fs=1200MSps, the sampling bit width is 12 bits, and it is stored in 16 bits for the convenience of data usage, and the data recording speed is 1200×2MB/s=2400MB/s. After channelized reception processing, the IQ data stream of 600 MSps is obtained by down-sampling after filtering. The data volume statistics after considering different extraction multiples are shown in Table 1. Table 1 is a summary table of recorded data rates under different processing bandwidths.

processing bandwidth type of data Sampling Rate data rate 500MHz Raw data 1200MSps 2400MB/s 500MHz baseband data 600MSps 2400MB/s 250MHz baseband data 300MSps 1200MB/s 125MHz baseband data 150MSps 600MB/s 62.5MHz baseband data 75MSps 300MB/s 31.25MHz baseband data 37.5MSps 150MB/s

After the anti-aliasing order is determined according to the preset effective signal bandwidth and sampling rate, the IF digital signal is then subjected to anti-aliasing filtering, and the IQ digital signal to be sampled is output. Improve the signal-to-noise ratio.

In the further explanation of the above system, the main control unit determines whether the digital intermediate frequency signal corresponding to the target frequency point satisfies the signal storage warning condition, and if so, issues a warning message. It should be noted that the system also supports a signal warning function. When the collected digital intermediate frequency signal meets certain conditions, a warning is issued to remind the user, and the user decides whether to start the acquisition and storage of the digital intermediate frequency signal.

The radio frequency signal acquisition, recording and playback system provided by the invention can ensure the communication against the infield test task and improve the simulation test ability by constructing the information exchange among the downconverter, the intermediate frequency signal recording unit and the upconverter; it can collect signal samples in real time. , the communication signal can be played back to the air as a real-time test signal, and it has the ability to view, monitor and display the spectrum.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that it can still be The technical solutions described in the foregoing embodiments are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (10)

1. The utility model provides a radio frequency signal acquisition record playback system which characterized in that, includes down converter, intermediate frequency signal recording element and up converter, wherein:

the down converter is used for receiving radio frequency signals and converting the radio frequency signals into intermediate frequency signals;

the intermediate frequency signal recording unit is used for receiving the intermediate frequency signal, converting the intermediate frequency signal into a digital intermediate frequency signal and storing the digital intermediate frequency signal in a solid-state disk array;

and the up-converter is used for receiving the intermediate frequency signal played back by the intermediate frequency signal recording unit from the solid-state disk array and converting the intermediate frequency signal into a radio frequency signal.

2. The radio frequency signal acquisition, recording and playback system according to claim 1, wherein the intermediate frequency signal recording unit includes a data acquisition unit, an intermediate frequency processing unit, a main control unit, a data storage unit, and a data playback unit, wherein:

the data acquisition unit is used for carrying out A/D conversion on the intermediate frequency signal to obtain a digital intermediate frequency signal;

the intermediate frequency processing unit is used for carrying out signal spectrum analysis on the digital intermediate frequency signal to obtain monitoring spectrum data and reporting the monitoring spectrum data to the main control unit; determining and collecting digital intermediate frequency signals corresponding to the target frequency points according to the monitoring frequency spectrum data;

the main control unit is used for displaying the monitoring frequency spectrum data, converting the digital intermediate frequency signals corresponding to the target frequency points into data files, and storing the data files in the solid-state disk array through the data storage unit;

and the data playback unit is used for performing D/A conversion on the digital intermediate frequency signals corresponding to the target frequency points to obtain intermediate frequency signals, and the intermediate frequency signals are converted into radio frequency signals by the up-converter.

3. The radio frequency signal acquisition, recording and playback system according to claim 2, wherein the intermediate frequency processing unit is specifically configured to: and performing signal spectrum analysis on the digital intermediate frequency signal according to preset monitoring parameters, and selecting a baseband digital signal with a preset sampling rate according to the requirements of spectrum bandwidth and resolution ratio to perform FFT (fast Fourier transform) and power spectrum calculation to obtain monitoring spectrum data.

4. The radio frequency signal acquisition, recording and playback system of claim 2, wherein the down converter comprises a first amplifier, a pre-filter, a first mixer, a first filter, a second amplifier, a second mixer, a second filter, a third amplifier, a booster, and a fourth amplifier, wherein:

the input end of the first amplifier is connected with a radio frequency signal, the output end of the first amplifier is connected with the input end of the pre-filter, the output end of the pre-filter is connected with the first input end of the first mixer, the second input end of the first mixer is connected with a first local oscillator signal, the output end of the first mixer is connected with the input end of the first filter, the output end of the first filter is connected with the input end of the second amplifier, the output end of the second amplifier is connected with the first input end of the second mixer, the second input end of the second mixer is connected with a second local oscillator signal, the output end of the second mixer is connected with the input end of the second filter, the output end of the second filter is connected with the input end of the third amplifier, the output end of the third amplifier is connected with the input end of the gain device, the output end of the gain device is connected with the input end of the fourth amplifier, and the output end of the fourth amplifier is connected with the data acquisition unit.

5. The radio frequency signal acquisition, recording and playback system according to claim 2, wherein the intermediate frequency processing unit includes an N-order anti-aliasing filter device, wherein:

and the N-order anti-aliasing filtering device is used for determining the order according to the preset effective signal bandwidth and the sampling rate, then determining the digital intermediate frequency signal corresponding to the target frequency point according to the monitoring frequency spectrum data, performing anti-aliasing filtering processing on the digital intermediate frequency signal corresponding to the target frequency point, and outputting the IQ digital signal to be sampled.

6. The radio frequency signal acquisition, recording and playback system according to claim 5, wherein the anti-aliasing filtering means of each order comprises a forward filtering unit and a backward filtering unit, the forward filtering unit comprises a forward mixer and a third filter, and the backward filtering unit comprises a backward mixer and a fourth filter.

7. The radio frequency signal acquisition, recording and playback system of claim 2, wherein the main control unit is further configured to: and determining whether the digital intermediate frequency signals corresponding to the target frequency points meet signal storage warning conditions, and if so, sending warning information.

8. The radio frequency signal acquisition, recording and playback system according to claim 2, wherein the main control unit is specifically configured to: and generating a graphical file based on the monitoring spectrum data, and displaying the graphical file.

9. The radio frequency signal acquisition, recording and playback system according to claim 2, wherein the up-converter is specifically configured to: and adjusting the central frequency to play back the intermediate frequency signal to obtain a radio frequency signal, and outputting the radio frequency signal.

10. The radio frequency signal acquisition, recording and playback system according to claim 2, wherein the data acquisition unit and the data playback unit respectively employ an FPGA mezzanine card high-speed ADC module and an FPGA mezzanine card high-speed DAC module.

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