Device and method for broadband signal channelized receiving and high-precision reconstruction

Abstract

The invention provides a broadband signal channelized receiving and high-precision reconstruction method and device, and belongs to the technical field of wireless communication broadband signal processing.The method comprises the steps that a preselection filtering module conducts first-stage channel division on broadband radio frequency signals; the receiving frequency conversion module performs down-conversion on the narrowband radio frequency signal to intermediate frequency, and the mirror image frequency is suppressed through an intermediate frequency filter; the digital channelization module performs down-conversion on the digital intermediate-frequency signal to a baseband, and realizes second-stage channel division by using a baseband digital channelization low-pass filter to obtain narrowband sub-signals; the high-precision reconstruction module synthesizes a broadband signal through up-conversion and interpolation filtering to obtain a reconstructed signal; the playback calibration module calculates the initial phase difference of the calibration signal among different channels for phase compensation, and obtains a reconstructed signal after phase calibration; and performing up-conversion on the reconstructed signal after phase calibration to radio frequency, and sending the reconstructed signal back to a frequency hopping communication system. According to the invention, the precision index and the engineering reliability of the channelized receiving and reconstruction design method are improved.

Description

Technical Field

[0001] The present application belongs to the technical field of wireless communication broadband signal processing, and more specifically, to a device and method for broadband signal channelization reception and high-precision reconstruction. Background Art

[0002] Wireless communication is an important means of communication. Complex electromagnetic environments and malicious human interference bring huge challenges to wireless communication. In the increasingly complex electromagnetic environment, frequency hopping communication technology has been proven to be an effective method for anti-interference communication. It can play the role of frequency diversity and interference diversity, effectively improve the transmission quality of wireless links and reduce interference. However, with the development of frequency hopping communication, the receiving bandwidth of the communication system receiver usually contains multiple signals with different bandwidths and arbitrary frequency hopping frequency positions, and the states of these signals such as bandwidth, position and number often change during the reception process. How to improve the data processing performance and efficiency of broadband receiving systems is an issue that needs to be studied urgently.

[0003] Channelized reception and reconstruction is an important technology applied to broadband receiving systems. Its basic idea is to use an analysis filter group to divide the working bandwidth into several narrower sub-bands, then perform corresponding signal processing in each narrowband channel, and finally reconstruct the sub-signals of each channel into a broadband signal through a comprehensive filter group. In practical engineering applications, the commonly used digital channelization technology has problems such as slow processing speed due to the high filter order and "pits" and "bumps" in the overlapping area of ​​spectral splicing after the divided channels, which brings great challenges to engineering matters and reconstruction accuracy after channelization. In addition, the working bandwidth of frequency hopping communication usually exceeds 200MHz. If the received signal of the entire working bandwidth is processed using digital channelization, the consumption of resources in the FPGA will be greatly increased. Therefore, with the increasing speed of wireless communication, broadband communication systems have an urgent need to improve communication capacity and signal processing rate. Among them, the traditional multi-channel channelization method based on independent digital down-conversion technology has large hardware consumption and large computational complexity. Summary of the invention

[0004] In view of the defects of the prior art, the purpose of the present application is to provide a method and device for broadband signal channelization reception and high-precision reconstruction, aiming to solve the engineering problems of broadband signal reception, reconstruction and data processing.

[0005] To achieve the above-mentioned purpose, on the one hand, the present application provides a device for receiving and reconstructing a wideband signal through channelization, including: an antenna front-end module, a preselection filter module, a receiving frequency conversion module, a digital extraction filter module, a digital channelization module, a high-precision reconstruction module and a playback calibration module connected in sequence; the output end of the playback calibration module is connected to the high-precision reconstruction module, the frequency hopping communication system and the antenna front-end module;

[0006] The antenna front-end module is used to limit and amplify the broadband RF signal, and couple the calibration signal, and send it to the pre-selection filter module through power division.

[0007] The pre-selection filter module is used to perform the first-level channel division on the broadband radio frequency signal through the pre-selection filter group, so as to realize the conversion of the broadband radio frequency signal into the narrowband radio frequency signal;

[0008] The receiving frequency conversion module is used to down-convert each narrowband RF signal to an intermediate frequency;

[0009] The digital extraction and filtering module is used to extract and filter the intermediate frequency narrowband radio frequency signal converted into a digital signal to reduce the data rate and filter out the high-order harmonic components extracted by sampling;

[0010] The digital channelization module is used to perform second-level channel division on each digital signal transmitted by the digital extraction and filtering module to obtain a narrowband sub-signal of each channel;

[0011] The high-precision reconstruction module is used to synthesize the narrowband sub-signals of each channel to obtain the reconstructed signal of the original working bandwidth;

[0012] The playback calibration module is used to generate a calibration signal and transmit it to the antenna front-end module, and calculate the initial phase difference of the calibration signal between different channels, obtain the calibration coefficient and transmit it to the high-precision reconstruction module to perform phase compensation on the channel to obtain the reconstructed signal after phase calibration; the reconstructed signal after phase calibration is up-converted to a radio frequency signal and sent back to the frequency hopping communication system.

[0013] Further preferably, the receiving frequency conversion module includes a local oscillator unit, a mixer and an intermediate frequency filter; the input end of the mixer is connected to the pre-selection filter and the local oscillator unit, and the output end is connected to the input end of the intermediate frequency filter; the output end of the intermediate frequency filter is connected to the digital extraction filter module; the local oscillator unit is used to generate the local oscillator signal required for the narrow-band RF signal of each channel; the mixer is used to mix the narrow-band RF signal of each channel with the corresponding local oscillator signal of a different frequency, and move the spectrum of the narrow-band RF signal to the same intermediate frequency; the intermediate frequency filter is used to filter out the image signal and spurious signal after mixing, and suppress out-of-band signals.

[0014] Further preferably, the extraction and filtering module comprises an analog-to-digital conversion unit, a digital extraction unit and a digital low-pass filter connected in sequence;

[0015] The analog-to-digital conversion unit is used to perform bandpass sampling on the intermediate frequency narrowband RF signal to obtain a narrowband digital signal; the digital extraction unit is used to extract the narrowband digital signal to reduce the data rate; the digital low-pass filter is used to filter out the high-order harmonic components of the narrowband digital signal generated by sampling and extraction.

[0016] Further preferably, the digital channelization module includes a digital down-conversion unit and a channel division filter; the input end of the digital down-conversion unit is connected to the extraction filter module, and the output end is connected to the channel division filter; the digital down-conversion unit is used to move the different channel signals transmitted by the digital low-pass filter to the baseband spectrum; the channel division filter is used to divide the different channel signals into channels at the baseband to obtain narrowband sub-signals for each channel.

[0017] Further preferably, the high-precision reconstruction module includes an interpolation operation unit, a low-pass filter, a digital up-conversion unit and a synthesizer connected in sequence;

[0018] The interpolation operation unit is used to increase the sampling rate of the frequency band signal of each channel transmitted by the channel division filter; the low-pass filter is used to filter out the spurious signal introduced by the shift of the signal frequency band after interpolation, and obtain the baseband signal; the digital up-conversion unit is used to up-convert the baseband signal of each channel and shift the frequency band to the frequency band position of the broadband intermediate frequency signal; the synthesizer is used to synthesize and add the channel signals of each channel transmitted by the digital up-conversion unit, restore the bandwidth of the working frequency band of the frequency hopping communication system for output, and output it to the playback calibration module.

[0019] Further preferably, the playback calibration module includes a calibration signal generating unit, an adjacent channel phase difference calculating unit, a calibration coefficient unit and a playback unit;

[0020] The output end of the calibration signal generating unit is connected to the antenna front-end module; the input end of the adjacent channel phase difference calculating unit is connected to the high-precision reconstruction module, and the output end is connected to the input end of the calibration coefficient unit; the output end of the calibration coefficient unit is connected to the high-precision reconstruction module; the input end of the playback unit is connected to the output end of the high-precision reconstruction module, and the output end thereof is connected to the frequency hopping communication system;

[0021] The calibration signal generating unit is used to generate a calibration signal at the frequency point where adjacent channels overlap, and input it into the antenna front-end module. The calibration signal is coupled with the broadband RF signal to enter the link; the adjacent channel phase difference calculating unit is used to calculate the phase difference between two adjacent channels through the phase of the calibration signal in the two adjacent channels; the calibration coefficient unit is used to substitute the phase difference of the adjacent channels into the calibration coefficient calculation formula to obtain the calibration coefficient, and before up-conversion, use one channel as the phase reference to perform phase compensation on the other channel; the playback unit is used to up-convert the calibrated reconstructed signal to RF, and send it back to the frequency hopping communication system through the DAC.

[0022] On the other hand, the present application provides a method for channelized reception and high-precision reconstruction of a broadband signal, comprising the following steps:

[0023] Step S1: Amplify the broadband RF signal by limiting, couple the signal to the calibration signal, and transmit the signal to the pre-selection filter module through power division multiplexing;

[0024] Step S2: performing first-level channel division on the broadband radio frequency signal to convert the broadband radio frequency signal into a narrowband radio frequency signal;

[0025] Step S3: down-convert each narrowband RF signal to an intermediate frequency and then perform analog-to-digital conversion, extraction and filtering to reduce the data rate and filter out the high-order harmonic components extracted by sampling;

[0026] Step S4: performing second-level channel division on each digital signal obtained in step S3 to obtain a narrowband sub-signal of each channel;

[0027] Step S5: synthesizing the narrowband sub-signal of each channel in step S4 to obtain a reconstructed signal of the original working bandwidth;

[0028] Step S6: Calculate the initial phase difference of the calibration signal between different channels, obtain the calibration coefficient to perform phase compensation on the channel, and then obtain the reconstructed signal after phase calibration;

[0029] Step S7: up-convert the reconstructed signal after phase calibration to a radio frequency signal and send it back to the frequency hopping communication system.

[0030] Further preferably, step S3 specifically includes the following steps:

[0031] Step S3.1: Obtain the local oscillator signal required for each narrowband RF signal, requiring the isolation between each local oscillator signal to be higher than a preset isolation threshold, and requiring each local oscillator signal to be referenced by a common crystal oscillator to ensure the amplitude consistency of the local oscillator signal after phase locking and frequency multiplication;

[0032] Step S3.2: Mix each narrowband RF signal with a local oscillator signal of a different frequency, down-convert each narrowband RF signal to the same intermediate frequency signal, and then filter through the intermediate frequency to remove the image frequency;

[0033] Step S3.3: performing bandpass sampling on the intermediate frequency narrowband radio frequency signal to obtain a narrowband digital signal after spectrum shifting;

[0034] Step S3.4: digitally extract the narrowband digital signal after the spectrum shifting in step S3.3 to reduce the data rate, and then filter the extracted narrowband digital signal to remove high-order harmonic components.

[0035] Further preferably, step S4 specifically includes the following steps:

[0036] Step S4.1: using digital down-conversion to mix the narrowband digital signal of each channel obtained in step S3 with local oscillator signals of different frequencies, and moving the narrowband digital signal obtained in step S3 to the baseband for channelization processing;

[0037] Step S4.2: The baseband sub-signal of each channel is subjected to channel division filtering. On the one hand, the image signal after down-conversion is filtered out. On the other hand, a unified digital channelization is performed at the baseband to obtain narrowband sub-signals of multiple channels.

[0038] Further preferably, step S5 specifically includes the following steps:

[0039] Step S5.1: performing polyphase interpolation and low-pass filtering on the narrowband sub-signal of each channel to restore the data rate of the broadband RF signal and filter out the harmonic components caused by the interpolation;

[0040] Step S5.2: up-convert the baseband signal after interpolation filtering and the local oscillator signal of different frequencies, and then send them to the synthesizer together to obtain a reconstructed signal of the original working bandwidth.

[0041] Further preferably, step S6 specifically includes the following steps:

[0042] Step S6.1: coupling the generated calibration signal and the received broadband radio frequency signal into the link; wherein the frequency of the calibration signal is the center frequency of the overlapping region of the adjacent channel frequency bands;

[0043] Step S6.2: Calculate the phase difference of the calibration signal between adjacent channels;

[0044] Step S6.3: Substitute the phase difference into the calibration coefficient calculation formula to obtain the calibration coefficient, perform phase compensation on the channel, and obtain the reconstructed signal after phase calibration;

[0045] Step S6.4: up-convert the reconstructed signal after phase calibration to a radio frequency signal, and transmit it to the frequency hopping communication system through digital-to-analog conversion.

[0046] In general, the above technical solutions conceived by this application have the following beneficial effects compared with the prior art:

[0047] The present application provides a method for channelized reception and high-precision reconstruction of broadband signals. By combining radio frequency circuits with digital signal processing, two-stage channelization of broadband signals is realized. On the basis of traditional digital channel processing, the advantages of easy channelization engineering, good filtering effect and strong robustness of radio frequency conditioning circuits are utilized to improve the engineering feasibility and reliability of the channelized reception and reconstruction design scheme.

[0048] The present application provides a method for receiving and reconstructing a wideband signal through channelization and high-precision. The working bandwidth of the original wideband signal is divided into multiple RF sub-signals through RF pre-selection filtering, and each sub-signal is digitally channelized at the baseband through analog and digital down-conversion to obtain multiple narrowband channels. A channel division filter is used to achieve passband flatness and stopband attenuation characteristics while requiring the filter band design to meet the principle of adjacent channel amplitude complementarity, thereby ensuring high-precision reconstruction.

[0049] In engineering practice, it is found that the start-up time of the analog local oscillator and the digital NCO is uncertain, which will cause initial phase differences between channels. This application proposes a phase calibration method. The playback calibration module generates a single-tone calibration signal and couples it with the broadband receiving signal into the entire link, calculates the phase difference of the calibration signal in the two channels, and obtains the calibration coefficient as the phase compensation between the channels, thereby eliminating the phase mismatch of the spectrum splicing in the overlapping area. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a principle block diagram of a broadband signal channelization receiving and high-precision reconstruction device provided in an embodiment of the present application;

[0051] Figure 2 is a circuit block diagram of an antenna front-end module provided in an embodiment of the present application;

[0052] Figure 3 is a circuit block diagram of a radio frequency signal conditioning unit provided in an embodiment of the present application;

[0053] Figure 4 It is a principle block diagram of a digital extraction filter module provided in an embodiment of the present application;

[0054] Figure 5 is a block diagram of the digital channelization principle provided by an embodiment of the present application;

[0055] Figure 6 It is a principle block diagram of a high-precision reconstruction module provided in an embodiment of the present application;

[0056] Figure 7 is a structural diagram of a phase calibration method provided in an embodiment of the present application;

[0057] Figure 8 This is a diagram showing the reconstruction of an uncalibrated broadband noise spectrum and a broadband white noise spectrum reconstruction effect after amplitude and phase calibration after a broadband white noise signal is injected into an experimental spectrum provided by an embodiment of the present application. DETAILED DESCRIPTION

[0058] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0059] The present application provides a device for channelized reception and high-precision reconstruction of broadband signals, which adopts a two-stage channelization combining a radio frequency signal conditioning unit and a digital signal processing unit; through a receiving antenna, an antenna front-end module, a pre-selection filter circuit, a digital channel division filter, a digital interpolation filter module, a signal reconstruction module, a DAC playback module and a phase calibration module, the broadband signal is first divided into multiple narrowband bandwidth channels for signal reception and processing, and then the narrowband signal of each channel is reconstructed and sent back to the frequency hopping communication system, and the calibration module is used to achieve phase compensation between different channels, so as to build a full-process architecture for channelized reception and reconstruction of broadband signals;

[0060] More specifically, the present application is oriented to the frequency hopping communication system, and constructs a broadband signal channelization reception and high-precision reconstruction framework combining RF circuits and digital processing, which solves the engineering difficulties of two-stage channelization reception of broadband signals and realizes high-precision reconstruction. In view of the large working bandwidth and high hopping rate of frequency hopping communication signals, the first-level channelization of broadband RF signals is realized through the pre-selection filtering of the RF circuit, and then the analog down-conversion is performed to the intermediate frequency signal to reduce the sampling rate of digital processing. Secondly, after ADC sampling and digital extraction filtering, the digital signal processing rate is reduced, and then input into the digital channelization module, and the digital down-conversion and channel division filter are used to further divide it into multiple parallel narrowband signal processing to complete the second-level channelization of the digital baseband signal. Finally, the spectrum splicing of each channel narrowband signal to the original working frequency band is completed through high-precision reconstruction, and the initial phase difference between different channels is compensated for using the calibration signal. The broadband signal channelization reception and high-precision reconstruction device can effectively solve the engineering implementation difficulties of broadband signal reception, reconstruction and data processing without affecting the frequency and performance of frequency hopping communication.

[0061] like Figure 1 As shown, the broadband signal channelization receiving and high-precision reconstruction device includes an antenna front-end module 00, a pre-selection filtering module 01, a receiving frequency conversion module 02, a digital extraction filtering module 03, a digital channelization module 04, a high-precision reconstruction module 05 and a playback calibration module 06;

[0062] The input end of the antenna front-end module 00 is connected to the receiving antenna and the playback calibration module, and the output end is connected to the RF signal conditioning circuit; wherein the receiving antenna is used to receive broadband RF signals; the playback calibration module outputs calibration signals; the antenna front-end module is used to complete the limiting amplification of broadband RF signals, couple the calibration signals, and send them to the RF pre-selection filter module through power division;

[0063] The input end of the pre-selection filter module 01 is connected to the antenna front-end module 00, and the output end is connected to the receiving frequency conversion module 02. The pre-selection filter module 01 is used to divide the first-level channel of the broadband radio frequency signal in the analog circuit to realize the conversion of the broadband radio frequency signal to the narrowband radio frequency signal;

[0064] The input end of the receiving frequency conversion module 02 is connected to the pre-selection filter module 01, and the output end is connected to the extraction filter module 03 of the digital signal processing unit through the ADC analog-to-digital converter. The receiving frequency conversion module 02 is used to down-convert each narrow-band RF signal to an intermediate frequency, thereby reducing the requirements for the A / D sampling rate;

[0065] The input end of the digital extraction and filtering module 03 is connected to the receiving frequency conversion module 02 of the radio frequency signal conditioning unit through the ADC, and the output end is connected to the digital channelization module 04; the digital extraction and filtering module 03 is used for extracting and filtering digital signals, reducing the data rate, increasing the digital signal processing speed, and filtering out the high-order harmonic components extracted by sampling;

[0066] The input end of the digital channelization module 04 is connected to the digital extraction and filtering module 03, and the output end is connected to the high-precision reconstruction module 05 of the signal playback unit. The digital channelization module 04 is used to divide the second-level channel of each sub-signal in the digital signal processing part;

[0067] The input end of the high-precision reconstruction module 05 is connected to the digital channelization module 04 of the digital signal processing unit and the playback calibration module 06 of the signal playback unit, and the output end is connected to the playback calibration module 06; the high-precision reconstruction module 05 is used to synthesize the sub-signals of each channel to obtain the reconstructed signal of the original working bandwidth;

[0068] The input end of the playback calibration module 06 is connected to the high-precision reconstruction module 05, and the output end is connected to the frequency-hopping communication system and the antenna front-end module 00. The playback calibration module 06 is used to up-convert the reconstructed signal into a radio frequency signal and send it back to the frequency-hopping communication system through the DAC; on the other hand, it generates a calibration signal and sends it to the antenna front-end module 00, and calculates the initial phase difference of the calibration signal between different channels, thereby obtaining the calibration coefficient.

[0069] The circuit block diagram of the antenna front-end module 00 is as follows Figure 2 As shown, it includes: a limiter 001, a low noise amplifier 002, a coupler 003 and a power divider 004; the limiter 001 limits the spatial signal received by the antenna, limits the signal input above 0dBm, and prevents large signal input from damaging the back-end equipment; the low noise amplifier 002 amplifies the low-power input signal to -10dBm to meet the subsequent data processing requirements; the coupler 003 couples the calibration signal to the broadband RF signal; the power divider 004 divides the coupled signal into multiple paths and inputs them to the pre-selection filter of each channel;

[0070] More specifically, the specific execution steps of the antenna front-end module 00 are as follows:

[0071] Step S01: The antenna receives a broadband RF signal and inputs it into the limiter 001 to limit the input signal power. If the received signal power is large, the limiter starts to work and reflects the high-power signal. The reflected signal is absorbed by the load through the 90° bridge. If the received power is a small signal, the limiter does not work. After amplification by the low-noise amplifier 002, the signal power meets the processing requirements.

[0072] Step S02: The broadband RF signal after limiting amplification and the calibration signal enter the coupler 003 together to obtain a coupled signal, which is then divided into multiple signals through a power divider;

[0073] The circuit block diagram of the RF signal conditioning unit is as follows: Figure 3 As shown, it includes: a pre-selection filter 01 and a receiving frequency conversion module 02; the receiving frequency conversion module 02 includes a local oscillator unit 021, a mixer 022 and an intermediate frequency filter 023; the pre-selection filter 01 performs bandpass processing on the broadband RF signal of each channel to obtain narrowband signals of different frequency bands, and suppress out-of-band noise and interference, requiring that the passband design of the pre-selection filter of each channel should overlap to prevent signal loss; the local oscillator unit 021 generates the local oscillator signal required for the narrowband RF signal of each channel, requiring that the local oscillator signals of different frequencies have a common crystal reference and have high isolation; the mixer 022 mixes the narrowband RF signal of each channel with the corresponding local oscillator signal of different frequencies, and moves the spectrum to the same intermediate frequency; the intermediate frequency filter 013 filters out the image signal and spurious signals after mixing, and further suppresses the out-of-band signal;

[0074] More specifically, each signal passes through the corresponding pre-selection filter 01 to obtain a different narrowband frequency band sub-signal, and the passband range of each pre-selection filter is set by the communication system, requiring that the passbands of the pre-selection filters of adjacent channels have overlapping areas;

[0075] Further preferably, the execution steps of the receiving frequency conversion module 02 are as follows:

[0076] Step S21: using the local oscillator unit 021 to generate the local oscillator signal required by each narrowband sub-signal, requiring high isolation between each local oscillator signal to prevent crosstalk, and requiring each local oscillator signal to be referenced by a common crystal oscillator to ensure the amplitude consistency of the local oscillator signal after phase locking and frequency multiplication;

[0077] Step S22: each sub-signal is mixed with a local oscillator signal of a different frequency 022, and the radio frequency signals are down-converted to the same intermediate frequency signal, and then the image frequency is filtered out through intermediate frequency filtering 023.

[0078] The principle block diagram of the extraction filter module 03 is as follows Figure 4As shown, it includes an analog-to-digital conversion unit 031, a digital extraction unit 032 and a digital low-pass filter 033; the analog-to-digital conversion unit 031 performs bandpass sampling on the intermediate frequency analog signal to obtain a digital signal; the digital extraction unit 032 is used to extract the digital signal to reduce the data rate; the digital low-pass filter 033 is used to filter out the high-order harmonic components generated by sampling and extraction;

[0079] More specifically, the extraction filter module 03 specifically performs the following steps:

[0080] Step S31: using the analog-to-digital conversion unit 031 to perform bandpass sampling on the intermediate frequency analog signal to obtain a narrowband digital signal after spectrum shifting;

[0081] Step S32: digitally decimating the sampled signal to reduce the data rate;

[0082] Step S33: filtering the sampled narrowband digital signal through the digital low-pass filter 033 to remove the high-order harmonic components, and dividing it into multiple signals and sending them to the digital channelization module;

[0083] The principle block diagram of the digital channelization module 04 is as follows: Figure 5 As shown, it includes a digital down-conversion unit 041 and a channel division filter 042; the digital down-conversion unit 041 is used to shift the spectrum of different channel signals to the baseband; the channel division filter is used to divide the signals of different channels in the baseband to obtain narrower sub-signals.

[0084] More specifically, the digital channelization method comprises the following steps:

[0085] Step S41: using digital down-conversion 041 to mix the digital signal of each channel with local oscillator signals of different frequencies, and moving the digital signal to the baseband for channelization processing;

[0086] Step S42: The baseband sub-signal of each channel is passed through the channel division filter 042, which, on the one hand, filters out the image signal after down-conversion, and, on the other hand, performs unified digital channelization at the baseband to obtain narrowband sub-signals of multiple channels.

[0087] The principle block diagram of high-precision reconstruction module 05 is as follows: Figure 6As shown, it includes an interpolation operation unit 051, a low-pass filter 052, a digital up-conversion unit 053 and a synthesizer 054; the interpolation operation unit 051 increases the sampling rate of the frequency band signals of each channel to ensure that the signal after the RF signal is combined can effectively distinguish the signals of each frequency point; the low-pass filter 052 is used to filter out the spurious signals caused by the shift of the signal frequency band after interpolation, and retain the baseband signal; the digital up-conversion unit 053 is used to up-convert the frequency band signal of each channel, and move the frequency band to the frequency band position of the original signal; the synthesizer 054 is used to synthesize and add the signals of each channel of each path, restore the bandwidth of the working frequency band of the frequency hopping communication system for output, and output it to the playback calibration module;

[0088] More specifically, the high-precision reconstruction method 05 includes the following steps:

[0089] Step S51: performing polyphase interpolation and low-pass filtering on the narrowband sub-signal of each channel to restore the original data rate and filter out the harmonic components caused by the interpolation;

[0090] Step S52: up-convert the narrowband signal after interpolation filtering and the local oscillator signal of different frequencies, and then send them to the synthesizer 054 to obtain a reconstructed signal of the original working bandwidth;

[0091] The principle block diagram of playback calibration module 06 is as follows Figure 7 As shown, it includes a calibration signal generating unit 061 for the frequency point of channel overlap, an adjacent channel phase difference calculating unit 062, a calibration coefficient unit 063 and a playback unit 064; the calibration signal generating unit 061 is used to generate a single tone signal at the frequency point where adjacent channels overlap, input it into the antenna front-end module, couple it with the broadband radio frequency signal, and enter the link; the adjacent channel phase difference calculating unit 062 obtains the phase of the calibration signal obtained after up-conversion in the high-precision reconstruction module 05 in two adjacent channels, calculates the phase difference between the two, and obtains the phase difference between the two channels caused by the uncertainty of the start-up time of the analog local oscillator and the digital NCO; the calibration coefficient unit 063 substitutes the phase difference of the adjacent channels into the calibration coefficient calculation formula to obtain the calibration coefficient, and before up-conversion, uses one channel as the phase reference to perform phase compensation on the other channel; the playback unit 064 is used to up-convert the calibrated reconstructed signal to radio frequency, and send it back to the frequency hopping communication system through the DAC.

[0092] More specifically, the playback calibration module 06 includes the following steps:

[0093] Step S61: Use the calibration signal unit 061 to generate a calibration signal, whose frequency is the center frequency of the overlapping area of ​​the adjacent channel frequency bands, input it to the antenna front-end module, couple it with the received RF broadband signal, and enter the link; wherein the calibration signal includes single-tone signals of different frequencies, and the single-tone signals of different frequencies are transmitted in sequence;

[0094] Step S62: Calculate the phase difference of the single tone signal between adjacent channels at the frequency;

[0095] Step S63: Substitute the phase difference into the calibration coefficient calculation formula to obtain the calibration coefficient, input it into the high-precision reconstruction module, and perform phase compensation on the channel;

[0096] Step S64: Send the reconstructed signal after phase calibration to the playback unit, up-convert it to a radio frequency signal, perform digital-to-analog conversion through DAC, and output it to the frequency hopping communication system.

[0097] Figure 8 The reconstructed spectrum of the broadband white noise signal injection experiment verifies the signal reconstruction effect of the channelization and high-precision device; the frequency components of the white noise signal have the same energy density and the amplitude is flat in the entire power spectrum, which is convenient for observing the spectrum splicing effect of signal reconstruction. Therefore, the signal source generates broadband white noise and injects it into the receiving antenna for channelization and reconstruction; through comparison, it is found that the reconstruction effect of the uncalibrated broadband noise spectrum appears "concave", but the reconstruction effect of the broadband white noise spectrum after amplitude and phase calibration shows that the power spectrum amplitude of the reconstructed signal is flat, indicating the feasibility of the channelized reception and high-precision reconstruction method, and verifying the engineering feasibility of the device developed by the present invention.

[0098] It should be understood that expressions such as “include” and “may include” used in the present application indicate the existence of disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements.

[0099] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense.

[0100] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A device for receiving broadband signals through channelization and reconstructing them with high precision. It is characterized in that include: An antenna front-end module, a preselection filter module, a receiving frequency conversion module, a digital extraction filter module, a digital channelization module, a high-precision reconstruction module and a playback calibration module connected in sequence; The output end of the playback calibration module is connected to the high-precision reconstruction module, the frequency hopping communication system and the antenna front-end module; The antenna front-end module is used to limit and amplify the broadband RF signal, and couple the calibration signal, and send it to the pre-selection filter module through power division. The pre-selection filter module is used to perform the first-level channel division on the broadband radio frequency signal through the pre-selection filter group, so as to realize the conversion of the broadband radio frequency signal into the narrowband radio frequency signal; The receiving frequency conversion module is used to down-convert each narrowband RF signal to an intermediate frequency; The digital extraction and filtering module is used to extract and filter the intermediate frequency narrowband radio frequency signal converted into a digital signal to reduce the data rate and filter out the high-order harmonic components extracted by sampling; The digital channelization module is used to perform second-level channel division on each digital signal transmitted by the digital extraction and filtering module to obtain a narrowband sub-signal of each channel; The high-precision reconstruction module is used to synthesize the narrowband sub-signals of each channel to obtain the reconstructed signal of the original working bandwidth; The playback calibration module is used to generate a calibration signal and transmit it to the antenna front-end module, and calculate the initial phase difference of the calibration signal between different channels, obtain the calibration coefficient and transmit it to the high-precision reconstruction module to perform phase compensation on the channel to obtain the reconstructed signal after phase calibration; the reconstructed signal after phase calibration is up-converted to a radio frequency signal and sent back to the frequency hopping communication system.

2. The device according to claim 1, It is characterized in that The receiving frequency conversion module includes a local oscillator unit, a mixer and an intermediate frequency filter; The input end of the mixer is connected to the preselection filter and the local oscillator unit, and the output end is connected to the input end of the intermediate frequency filter; The output end of the intermediate frequency filter is connected to the digital extraction filter module; The local oscillator unit is used to generate the local oscillator signal required for the narrowband RF signal of each channel; the mixer is used to mix the narrowband RF signal of each channel with the corresponding local oscillator signal of different frequency, and move the spectrum of the narrowband RF signal to the same intermediate frequency; The intermediate frequency filter is used to filter out the image signal and spurious signal after mixing, and suppress the out-of-band signal.

3. The device according to claim 1 or 2, It is characterized in that The extraction and filtering module includes an analog-to-digital conversion unit, a digital extraction unit and a digital low-pass filter connected in sequence; The analog-to-digital conversion unit is used to perform bandpass sampling on the intermediate frequency narrowband radio frequency signal to obtain a narrowband digital signal; The digital extraction unit is used to extract the narrowband digital signal and reduce the data rate; Digital low-pass filters are used to filter out high-order harmonic components of narrow-band digital signals caused by sampling and extraction.

4. The device according to claim 3, It is characterized in that The digital channelization module includes a digital down-conversion unit and a channel division filter; the input end of the digital down-conversion unit is connected to the extraction filter module, and the output end is connected to the channel division filter; the digital down-conversion unit is used to move the different channel signals transmitted by the digital low-pass filter to the baseband spectrum; the signal division filter is used to divide the different channel signals into channels at the baseband to obtain narrower sub-signals for each channel.

5. The device according to claim 4, It is characterized in that The high-precision reconstruction module includes an interpolation operation unit, a low-pass filter, a digital up-conversion unit and a synthesizer connected in sequence; The interpolation operation unit is used to increase the sampling rate of the frequency band signal of each channel transmitted by the channel division filter; The low-pass filter is used to filter out the spurious signal introduced by the shift of the signal frequency band after interpolation to obtain the baseband signal; The digital up-conversion unit is used to up-convert the baseband signal of each channel and move the frequency band to the frequency band position of the broadband intermediate frequency signal; The synthesizer is used to synthesize and add the channel signals of each channel transmitted by the digital up-conversion unit, restore the bandwidth of the working frequency band of the frequency hopping communication system for output, and output it to the playback calibration module.

6. The device according to claim 1 or 5, It is characterized in that The playback calibration module includes a calibration signal generating unit, an adjacent channel phase difference calculating unit, a calibration coefficient unit and a playback unit; The output end of the calibration signal generating unit is connected to the antenna front-end module; the input end of the adjacent channel phase difference calculating unit is connected to the high-precision reconstruction module, and the output end is connected to the input end of the calibration coefficient unit; the output end of the calibration coefficient unit is connected to the high-precision reconstruction module; the input end of the playback unit is connected to the output end of the high-precision reconstruction module, and the output end thereof is connected to the frequency hopping communication system; The calibration signal generating unit is used to generate a calibration signal at the frequency point where adjacent channels overlap, and input it into the antenna front-end module. The calibration signal is coupled with the broadband RF signal to enter the link; The adjacent channel phase difference calculation unit is used to calculate the phase difference between two adjacent channels by calibrating the phases of the signals in the two adjacent channels; The calibration coefficient unit is used to substitute the phase difference between adjacent channels into the calibration coefficient calculation formula to obtain the calibration coefficient and transmit it to the high-precision reconstruction module. Before up-conversion, one channel is used as the phase reference to perform phase compensation on the other channel. The playback unit is used to up-convert the calibrated reconstructed signal to RF and send it back to the frequency hopping communication system through the DAC.

7. A method based on the device according to claim 1, It is characterized in that The following steps are involved: Step S1: Amplify the broadband RF signal by limiting, couple the signal to the calibration signal, and transmit the signal to the pre-selection filter module through power division multiplexing; Step S2: performing first-level channel division on the broadband radio frequency signal to convert the broadband radio frequency signal into a narrowband radio frequency signal; Step S3: down-convert each narrowband RF signal to an intermediate frequency and then perform analog-to-digital conversion, extraction and filtering to reduce the data rate and filter out the high-order harmonic components extracted by sampling; Step S4: performing second-level channel division on each digital signal obtained in step S3 to obtain a narrowband sub-signal of each channel; Step S5: synthesizing the narrowband sub-signal of each channel in step S4 to obtain a reconstructed signal of the original working bandwidth; Step S6: Calculate the initial phase difference of the calibration signal between different channels, obtain the calibration coefficient, perform phase compensation on the channel, and then obtain the reconstructed signal after phase calibration; Step S7: up-convert the reconstructed signal after phase calibration to a radio frequency signal and send it back to the frequency hopping communication system.

8. The device according to claim 7, It is characterized in that Step S3 specifically includes the following steps: Step S3.1: Obtain the local oscillator signal required for each narrowband RF signal, requiring the isolation between each local oscillator signal to be higher than a preset isolation threshold, and requiring each local oscillator signal to be referenced by a common crystal oscillator to ensure the amplitude consistency of the local oscillator signal after phase locking and frequency multiplication; Step S3.2: Mix each narrowband RF signal with a local oscillator signal of a different frequency, down-convert each narrowband RF signal to the same intermediate frequency signal, and then filter out the image frequency through intermediate frequency filtering; Step S3.3: performing bandpass sampling on the intermediate frequency narrowband radio frequency signal to obtain a narrowband digital signal after spectrum shifting; Step S3.4: digitally extract the narrowband digital signal after the spectrum shifting in step S3.3 to reduce the data rate, and then filter the extracted narrowband digital signal to remove high-order harmonic components.

9. The device according to claim 8, It is characterized in that Step S4 specifically includes the following steps: Step S4.1: using digital down-conversion to mix the narrowband digital signal of each channel obtained in step S3 with local oscillator signals of different frequencies, and moving the narrowband digital signal obtained in step S3 to the baseband for channelization processing; Step S4.2: The baseband sub-signal of each channel is subjected to channel division and filtering, to filter out the image signal after down-conversion on the one hand, and to perform unified digital channelization at the baseband on the other hand, to obtain narrowband sub-signals of multiple channels.

10. The device according to any one of claims 7 to 9, It is characterized in that Step S5 specifically includes the following steps: Step S5.1: performing polyphase interpolation and low-pass filtering on the narrowband sub-signal of each channel to restore the data rate of the broadband RF signal and filter out the harmonic components caused by the interpolation; Step S5.2: up-convert the interpolation filtered baseband signal and the local oscillator signal of different frequencies, and then send them to the synthesizer together to obtain a reconstructed signal of the original working bandwidth; Step S6 specifically includes the following steps: Step S6.1: coupling the generated calibration signal and the received broadband radio frequency signal into the link; wherein the frequency of the calibration signal is the center frequency of the overlapping region of the adjacent channel frequency bands; Step S6.2: Calculate the phase difference of the calibration signal between adjacent channels; Step S6.3: Substitute the phase difference into the calibration coefficient calculation formula to obtain the calibration coefficient, perform phase compensation on the channel, and obtain the reconstructed signal after phase calibration; Step S6.4: up-convert the reconstructed signal after phase calibration to a radio frequency signal, and transmit it to the frequency hopping communication system through digital-to-analog conversion.

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