Broadband time domain digital beam forming method and device based on digital intermediate frequency integer sampling period delay, equipment and medium

Abstract

The invention provides a broadband time domain digital beam forming method and device based on digital intermediate frequency integer sampling period delay, equipment and a medium. The method comprises the following steps: receiving a broadband signal according to a signal receiving model for establishing a uniform linear array to obtain a received signal; according to the carrier frequency estimation value of the receiving signal of each array element, performing down-conversion and filtering operation on the receiving signal of each array element to obtain a digital intermediate frequency signal of each array element; performing phase compensation on the digital intermediate frequency signal of each array element according to the target phase difference of the first array element relative to the reference array element to obtain a compensated digital intermediate frequency signal of each array element; performing time delay processing on the compensation digital intermediate frequency signal of each array element according to the sampling period to obtain a time delay digital intermediate frequency signal of each array element; and obtaining a broadband signal beam according to the delay digital intermediate frequency signal of each array element. According to the invention, the beam pointing error caused by carrier frequency is reduced, the use of a digital filter is avoided, and the consumption of computing resources is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of signal processing, and in particular, to a broadband time-domain digital beamforming method, device, equipment and medium based on digital intermediate frequency integer sampling period delay. Background Art

[0002] Broadband time-domain digital beamforming can improve the signal-to-noise ratio of signals and has the ability of spatial filtering, and is widely used in fields such as detection and communication. Broadband time-domain digital beamforming processes the time-domain sampling sequence received by the antenna array through the designed weighting coefficients to achieve beam pointing in a specified direction, while suppressing environmental interference signals and reducing their impact on target signals. Broadband time-domain digital beamforming can improve the spatial resolution ability, signal gain and spatial coverage rate of the receiving system. Therefore, studying broadband time-domain digital beamforming technology has important significance and value. With the continuous development of digital signal processing technology and high-performance analog-to-digital converters, beam synthesis technology can be realized by digital circuits in intermediate frequency signals, and many broadband digital beamforming algorithms have been proposed accordingly. However, further research is still needed to design algorithms with less resource consumption and wide applicability.

[0003] Through the retrieval of existing technical literature, it is found that Liu Mingxin et al. published "Broadband Digital Array Radar Beamforming Based on Radio Frequency Sampling" in "Radar Science and Technology" (2020, 18(4): 394-398), and digital beamforming is performed through radio frequency direct sampling data. This method mainly performs broadband time-domain digital beamforming in the radio frequency domain. However, as the radio frequency increases, this method will no longer be applicable. Yu Kai et al. proposed a "Broadband Digital Beamforming Technology of a Fractional Delay Filter" in the second issue of "China Radar" (2014, 25-27), and gave a digital beamforming method based on a Farrow structure filter. This method performs down-conversion, phase shift compensation and digital delay filter processing on the array received signal, uses an FIR filter to achieve broadband beamforming, adjusts the signal phase of each antenna element through the weight coefficients of the filter, and concentrates the energy in a specific direction. This method has flexibility and designability, but it is necessary to calculate the delay filter coefficients of each channel, and the resource consumption is relatively large.

[0004] The retrieval results of existing literature show that the existing broadband digital beamforming methods have problems such as high resource consumption and limited applicability. Summary of the Invention

[0005] The present invention aims to provide a broadband time-domain digital beamforming method, device, equipment and medium based on digital intermediate frequency integer sampling period delay to solve the problems of high resource consumption and limited applicability existing in broadband digital beamforming methods.

[0006] In a first aspect, the present invention provides a broadband time-domain digital beamforming method based on digital intermediate frequency integer sampling period delay, including:

[0007] Receiving a broadband signal according to a signal reception model established for a uniform linear array to obtain a received signal;

[0008] Performing down-conversion and filtering operations on the received signal of each element according to the estimated carrier frequency value of the received signal of each element to obtain the digital intermediate frequency signal of each element;

[0009] Performing phase compensation on the digital intermediate frequency signal of each element according to the target phase difference of the first element relative to the reference element to obtain the compensated digital intermediate frequency signal of each element;

[0010] Performing time delay processing on the compensated digital intermediate frequency signal of each element according to the sampling period to obtain the time delay digital intermediate frequency signal of each element;

[0011] Obtaining a broadband signal beam according to the time delay digital intermediate frequency signal of each element.

[0012] In some embodiments, the spacing between the reference element and the first element in the signal reception model is the element spacing.

[0013] In some embodiments, the received signal satisfies:

[0014] x 0 (t) = Arect(t / T 1 )cos(2πft);

[0015] x i (t) = Arect((t + τ) / T 1 )cos(2πf(t + τ));

[0016] Where x 0 (t) is the received signal of the reference element at time t, A is the amplitude of the signal, rect(t / T 1 ) represents a pulse signal with a pulse width of T 1 , f is the frequency, x i (t) is the received signal of the i-th element at time t, i = 1,..., N - 1, d is the element spacing, θ is the incident azimuth angle, and c is the speed of light.

[0017] In some embodiments, the method for obtaining the estimated carrier frequency value of the received signal of each element includes:

[0018] Detecting and estimating the carrier frequency parameter of the received signal of each element to obtain the estimated carrier frequency value;

[0019] Perform down-conversion operation on the received signal according to the carrier frequency estimation value to obtain a down-converted signal;

[0020] Input the down-converted signal into a digital low-pass filter to obtain a digital intermediate frequency signal.

[0021] In some embodiments, the down-converted signal satisfies:

[0022]

[0023] where is the down-converted signal of the i-th array element at time t, is the carrier frequency estimation value.

[0024] In some embodiments, the method for obtaining the target phase difference of the first array element relative to the reference array element includes:

[0025] According to the down-converted signal of each array element, obtain the corresponding relationship between the down-converted signal of each array element and the down-converted signal of the reference array element;

[0026] According to the corresponding relationship, obtain the expression of the phase difference of each array element relative to the reference array element;

[0027] Decompose the first expression of the target phase difference of the first array element relative to the reference array element to obtain a second expression including the carrier frequency estimation value and the time delay;

[0028] Solve the second expression according to the carrier frequency estimation value and the time delay to obtain the target phase difference of the first array element relative to the reference array element.

[0029] In some embodiments, the time-delay digital intermediate frequency signal satisfies:

[0030]

[0031] where n i = min{iτ - n i Δt}, representing the number of sampling points corresponding to the minimum time-delay error of the i-th channel.

[0032] In a second aspect, the present invention provides a broadband time-domain digital beamforming device based on digital intermediate frequency integer sampling period delay, including:

[0033] A signal receiving module, configured to receive a broadband signal according to a signal receiving model established for a uniform linear array to obtain a received signal;

[0034] A digital intermediate frequency signal module, configured to perform down-conversion and filtering operations on the received signal of each array element according to the carrier frequency estimation value of the received signal of each array element to obtain the digital intermediate frequency signal of each array element;

[0035] A phase compensation module, configured to perform phase compensation on the digital intermediate frequency signals of each element according to the target phase difference between the first element and the reference element, so as to obtain the compensated digital intermediate frequency signals of each element;

[0036] A time delay processing module, configured to perform time delay processing on the compensated digital intermediate frequency signals of each element according to the sampling period, so as to obtain the time delay digital intermediate frequency signals of each element;

[0037] A broadband signal beam module, configured to obtain a broadband signal beam according to the time delay digital intermediate frequency signals of each element.

[0038] In a third aspect, the present invention provides an electronic device, including: a memory and a processor;

[0039] The memory stores computer-executable instructions;

[0040] The processor executes the computer-executable instructions stored in the memory, so that the processor executes the method as in the first aspect.

[0041] In a fourth aspect, the present invention provides a computer-readable storage medium, in which computer-executable instructions are stored, and when the computer-executable instructions are executed by a processor, they are used to implement the method as in the first aspect.

[0042] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows: Based on the characteristic of the short sampling period of the current analog-to-digital converter, digital beamforming is performed using digital intermediate frequency signals, mainly including phase compensation, and time delay matching is performed through a digital delay line. This method reduces the beam pointing error caused by the carrier frequency, and at the same time avoids the use of digital filters, reducing the consumption of computing resources, and has prospects for engineering applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a schematic flowchart of a broadband time-domain digital beamforming method based on digital intermediate frequency integer sampling period delay proposed in an embodiment of the present invention;

[0044] Figure 2 It is a schematic structural diagram of a signal reception model of a uniform linear array proposed in an embodiment of the present invention;

[0045] Figure 3 It is a schematic diagram of a beam pointing at 0 degrees proposed in an embodiment of the present invention;

[0046] Figure 4 It is a schematic diagram of a beam pointing at 60 degrees proposed in an embodiment of the present invention;

[0047] Figure 5 It is a schematic diagram of a beam pointing at 45 degrees proposed in an embodiment of the present invention;

[0048] Figure 6 Schematic diagram of FFT comparison proposed in an embodiment of the present invention;

[0049] Figure 7 Schematic diagram of the real part of the time-domain waveform of channel 1 and the time-domain waveform after digital beamforming proposed in an embodiment of the present invention;

[0050] Figure 8 Schematic diagram of the imaginary part of the time-domain waveform of channel 1 and the time-domain waveform after digital beamforming proposed in an embodiment of the present invention;

[0051] Figure 9 Schematic diagram of the structure of a broadband time-domain digital beamforming device based on digital intermediate frequency integer sampling period delay proposed in an embodiment of the present invention;

[0052] Figure 10 Schematic diagram of the structure of an electronic device proposed in an embodiment of the present invention. Detailed implementation manners

[0053] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated herein can be arranged and designed in various different configurations.

[0054] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0055] Embodiment

[0056] As Figure 1 shown, an embodiment of the present invention proposes a broadband time-domain digital beamforming method based on digital intermediate frequency integer sampling period delay, including the following steps:

[0057] S101. According to the signal reception model of a uniform linear array, receive a broadband signal to obtain a received signal.

[0058] Figure 2 Schematic diagram of the structure of the signal reception model of a uniform linear array proposed in an embodiment of the present invention. As Figure 2 shown, for an N-element uniform linear array with an element spacing of d, there is a carrier frequency of f 0, A broadband signal with a bandwidth of B is incident on the array surface from the direction of the incident azimuth angle θ, and the element antenna is considered as a non-directional sensor. Let the received signal of the reference element be:

[0059] x 0 (t) = Arect(t / T 1 )cos(2πft)

[0060] where the sampling frequency is f s , and the frequency f conforms to a broadband signal with a carrier frequency of f 0 , a bandwidth of B, A is the amplitude of the signal, and rect(t / T 1 ) represents a pulse signal with a pulse width of T 1 . According to the array geometric relationship, the received signal of the i-th element is:

[0061] x i (t) = Arect((t + τ) / T 1 )cos(2πf(t + τ))

[0062] where i = 1,..., N - 1, d is the element spacing, and c = 3×10 8 is the speed of light.

[0063] S102. According to the estimated carrier frequency value of the received signal of each element, perform down-conversion and filtering operations on the received signal of each element to obtain the digital intermediate-frequency signal of each element.

[0064] Specifically, the estimated carrier frequency value can be obtained by detecting and estimating the carrier frequency parameters of the received signal of each element;

[0065] Perform down-conversion operation on the received signal according to the estimated carrier frequency value to obtain the down-converted signal;

[0066] Input the down-converted signal into a digital low-pass filter to obtain the digital intermediate-frequency signal.

[0067] Among them, the down-converted signal can be expressed as:

[0068]

[0069] where is the estimated carrier frequency value, and j is the imaginary unit.

[0070] After performing operations such as down-conversion and filtering, the digital intermediate-frequency signal of x i (t) can be obtained.

[0071] S103. According to the target phase difference of the first element relative to the reference element, perform phase compensation on the digital intermediate-frequency signal of each element to obtain the compensated digital intermediate-frequency signal of each element.

[0072] Among them, the method for obtaining the target phase difference of the first array element relative to the reference array element may include:

[0073] According to the down-converted signals of each array element, obtain the corresponding relationship between the down-converted signal of each array element and the down-converted signal of the reference array element;

[0074] According to the corresponding relationship, obtain the expression of the phase difference of each array element relative to the reference array element;

[0075] Decompose the first expression of the target phase difference of the first array element relative to the reference array element to obtain a second expression including the carrier frequency estimate value and the time delay;

[0076] Solve the second expression according to the carrier frequency estimate value and the time delay to obtain the target phase difference of the first array element relative to the reference array element.

[0077] Specifically, and The relationship between them can be expressed as:

[0078]

[0079] It can be obtained that the phase difference of the i-th array element relative to the reference array element is:

[0080]

[0081] Decompose the phase difference of the i-th array element relative to the reference array element into two parts as:

[0082]

[0083] Among them, the time delay τ is the time delay corresponding to the specified beam direction. According to and τ,

[0084] According to And perform phase compensation on the digital intermediate frequency signals of each array element to obtain:

[0085]

[0086] The of the i-th array element relative to the reference array element

[0087]

[0088] Among them,

[0089] Among them, is the compensated digital intermediate frequency signal of the i-th array element.

[0090] S104. Perform time-delay processing on the compensated digital intermediate-frequency signals of each array element according to the sampling period to obtain the time-delay digital intermediate-frequency signals of each array element.

[0091] Among them, the sampling period can be obtained according to the sampling frequency f s and the sampling period Δt = 1 / f s .

[0092] Use the sampling period as the interval of the digital delay line to perform time delay on the data of each channel, and obtain:

[0093]

[0094] where n i = min{iτ - n i Δt}, representing the number of sampling points corresponding to the minimum time-delay error of the i-th channel.

[0095] S105. Obtain the broadband signal beam according to the time-delay digital intermediate-frequency signals of each array element.

[0096] Among them, perform an accumulation operation on p i (t) to achieve digital beamforming:

[0097]

[0098] Exemplarily:

[0099] Step 1. Assume there is a 16-element uniform linear array with an element spacing d = 75 mm. The signal frequency is 1.4 GHz, the bandwidth is 400 MHz, the sampling frequency is 5 GHz, the signal simulation length is 1 μs, the pulse width is 0.1 μs, and the duty cycle is 10%.

[0100] Step 2. Detect the signal and estimate the carrier frequency parameters, and perform down-conversion and filtering operations according to the measured signal frequency. The bandwidth of the low-pass filter is 800 MHz and the data rate is 1600 MHz.

[0101] Step 3. Calculate and τ, and then obtain Compensate the phase of the digital intermediate-frequency signal to obtain

[0102]

[0103] Step 4. Perform time delay on the digital intermediate-frequency signal.

[0104] The i-th array element relative to the reference array element has a phase difference of

[0105]

[0106] Among them, According to the sampling frequency f s the sampling period Δt = 1 / f can be obtained s . The sampling period is used as the interval of the digital delay line to delay the data of N channels:

[0107]

[0108] Among them, n i = min{iτ - n i Δt}, representing the number of sampling points corresponding to the minimum delay error of the i-th channel.

[0109] Step Five, perform wideband time-domain digital beamforming.

[0110] Perform an accumulation operation on p i (t) to achieve digital beamforming:

[0111]

[0112] Among them, Figure 3 is the schematic diagram of the beam pointing at 0 degrees proposed in the embodiment of the present invention. There are 3 signal sources, and their azimuth angles are all 0°, and the frequencies are 1.2 GHz, 1.4 GHz, and 1.6 GHz respectively, that is, in the normal direction of the beam pointing. Through Figure 3 it can be obtained that the maximum gains of the 3 signals all appear at 0 degrees, and the gains are all 24.0824 dB. According to the principle of digital beamforming, the gain after the accumulation of the data of 16 channels is 20log 10 16 = 24.0824 dB, and the simulation is consistent with the relevant theory. At the same time, since the carrier frequencies of the 3 signals are different, there are differences in their 3 dB beam widths, and the beam width of the 1.6 GHz signal is the narrowest. According to the 3 dB beam width calculation formula

[0113]

[0114] it can be obtained that the beam widths of the three signal sources at the azimuth angle of 0° are 10.6355°, 9.1162°, and 7.9766° respectively. In Figure 2 with a search interval of 1° traversing [-90, 90], it can be obtained that their beam widths are approximately 10°, 10°, and 8°, and the simulation is consistent with the theory.

[0115] Figure 4 is the schematic diagram of the beam pointing at 60 degrees proposed in the embodiment of the present invention. Other simulation conditions are the same as Figure 3 the same. Due to the difference between the time delay and the sampling period, the beam pointing will deviate, but according to Figure 3It can be obtained that the maximum gain of the three signals still appears at 60°. The gains of the 1 GHz, 1.2 GHz, and 1.4 GHz signals are 24.0644, 24.0824, and 24.0642 respectively. The gain of the 1.2 GHz frequency signal is equal to the theoretical value, but the gains of the 1 GHz and 1.4 GHz signals show a slight decrease. At the same time, the beams of the three signals are all broadened. Their simulated beam widths are 16°, 19°, and 22°, corresponding to the theoretical values of 15.95°, 18.2323°, and 21.2711° respectively.

[0116] Figure 5 This is the schematic diagram of the beam pointing at 45 degrees proposed in the embodiment of the present invention. To study the influence of frequency on digital beamforming, a chirp signal with a center frequency of 0.6 GHz and a bandwidth of 400 MHz is considered, and the incident azimuth angle is 45°. Other simulation conditions are the same as Figure 3 the same. In Figure 5 , three frequency points are randomly selected as references within the 400 MHz bandwidth. It can be obtained that the beam pointing of the signals within the bandwidth is all 45°.

[0117] Figure 6 This is the schematic diagram of the comparison of FFT (Fast Fourier Transform) proposed in the embodiment of the present invention. To verify whether the formation of DBF (Digital Beam) will cause distortion of the signal time-domain waveform, Figure 6 respectively gives the spectrogram obtained after filtering the reference array element data (channel 1 data), and the spectrogram of the beam signal obtained after passing through the digital delay line and accumulation. From Figure 6 it can be obtained that with the change of frequency, the gain of DBF is relatively stable and fluctuates around 24 dB.

[0118] Figure 7 This is the schematic diagram of the real part of the time-domain waveform of channel 1 and the time-domain waveform after digital beamforming proposed in the embodiment of the present invention, Figure 8 This is the schematic diagram of the imaginary part of the time-domain waveform of channel 1 and the time-domain waveform after digital beamforming proposed in the embodiment of the present invention. Combining Figure 7 and Figure 8 it can be concluded that digital beamforming increases the amplitude of the signal by 16 times and does not cause waveform distortion.

[0119] Compared with the prior art, in view of the problem of excessive resource consumption caused by the existing method using a digital delay filter for digital intermediate frequency signals, the present invention proposes a broadband signal beamforming method based on digital intermediate frequency delay. Based on the characteristic of the short sampling period of the current analog-to-digital converter, this method uses digital intermediate frequency signals for digital beamforming, mainly including phase compensation and time delay matching through a digital delay line. This method reduces the beam pointing error caused by the carrier frequency, and at the same time avoids the use of digital filters, reducing the consumption of computing resources and having the prospect of engineering application.

[0120] Figure 9 FIG. is a schematic structural diagram of a broadband time-domain digital beamforming device based on digital intermediate frequency integer sampling period delay proposed in an embodiment of the present invention. The device 90 includes:

[0121] A signal receiving module 901, configured to receive a broadband signal according to a signal receiving model for establishing a uniform linear array, and obtain a received signal;

[0122] A digital intermediate frequency signal module 902, configured to perform down-conversion and filtering operations on the received signal of each array element according to the estimated carrier frequency value of the received signal of each array element, and obtain the digital intermediate frequency signal of each array element;

[0123] A phase compensation module 903, configured to perform phase compensation on the digital intermediate frequency signal of each array element according to the target phase difference between the first array element and the reference array element, and obtain the compensated digital intermediate frequency signal of each array element;

[0124] A time delay processing module 904, configured to perform time delay processing on the compensated digital intermediate frequency signal of each array element according to the sampling period, and obtain the time delay digital intermediate frequency signal of each array element;

[0125] A broadband signal beam module 905, configured to obtain a broadband signal beam according to the time delay digital intermediate frequency signal of each array element.

[0126] A broadband time-domain digital beamforming device based on digital intermediate frequency integer sampling period delay provided in an embodiment of the present invention can execute the method provided in the above method embodiment, and its implementation principle and technical effects are similar, which will not be elaborated here in this embodiment.

[0127] Figure 10 FIG. is a schematic structural diagram of an electronic device proposed in an embodiment of the present invention. As Figure 10 shown, the electronic device 100 provided in an embodiment of the present invention includes: at least one processor 1001 and a memory 1002. Optionally, the device 100 further includes a communication component 1003. Among them, the processor 1001, the memory 1002, and the communication component 1003 are connected through a bus 1004.

[0128] In a specific implementation process, at least one processor 1001 executes computer-executable instructions stored in a memory 1002, so that at least one processor 1001 executes the above-mentioned method.

[0129] For the specific implementation process of the processor 1001, reference may be made to the above-mentioned method embodiment, and its implementation principle and technical effects are similar, so they will not be elaborated here in this embodiment.

[0130] In the above embodiments, it should be understood that the processor may be a central processing unit (CPU), or may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The steps of the method disclosed in combination with the invention can be directly implemented by a hardware processor, or can be implemented by a combination of hardware and software modules in the processor.

[0131] The memory may include a random access memory (RAM), and may also include a non-volatile memory (NVM), such as at least one disk memory.

[0132] The bus may be an industry standard architecture (ISA) bus, a peripheral component interconnect (PCI) bus, an extended industry standard architecture (EISA) bus, etc. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, the buses in the drawings of the present invention are not limited to only one bus or one type of bus.

[0133] The present invention also provides a computer program product, including a computer program, which implements the above-mentioned method when executed by a processor.

[0134] The present invention also provides a computer-readable storage medium, in which computer-executable instructions are stored, and when the processor executes the computer-executable instructions, the above-mentioned method is implemented.

[0135] The above-readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, a magnetic disk, or an optical disk. The readable storage medium can be any available medium accessible by a general-purpose or special-purpose computer.

[0136] An exemplary readable storage medium is coupled to the processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can be located in an application specific integrated circuit (ASIC). Of course, the processor and the readable storage medium can also exist as discrete components in a device.

[0137] The division of units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be indirect couplings or communication connections through some interfaces, devices, or units, and can be in electrical, mechanical, or other forms.

[0138] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiments of the present invention.

[0139] In addition, in each embodiment of the present invention, the functional units can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit.

[0140] If a function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs that can store program codes.

[0141] Those of ordinary skill in the art can understand that all or part of the steps for implementing the above method embodiments can be completed by hardware related to program instructions. The foregoing program can be stored in a computer-readable storage medium. When this program is executed, it executes the steps including the above method embodiments; and the foregoing storage medium includes: various media such as ROM, RAM, magnetic disks, or optical discs that can store program codes.

[0142] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A broadband time-domain digital beamforming method based on digital intermediate frequency integer sampling period delay, characterized in that: include: According to the signal receiving model of the uniform linear array, the broadband signal is received to obtain a received signal; According to the carrier frequency estimation value of the received signal of each array element, down-converting and filtering operations are performed on the received signal of each array element to obtain a digital intermediate frequency signal of each array element; Performing phase compensation on the digital intermediate frequency signal of each array element according to the target phase difference of the first array element relative to the reference array element to obtain a compensated digital intermediate frequency signal of each array element; Performing time delay processing on the compensated digital intermediate frequency signal of each array element according to the sampling period to obtain a delayed digital intermediate frequency signal of each array element; A broadband signal beam is obtained based on the delayed digital intermediate frequency signal of each array element.

2. The broadband time-domain digital beamforming method based on digital intermediate frequency integer sampling period delay according to claim 1 is characterized in that: The spacing between the reference array element and the first array element in the signal receiving model is the array element spacing.

3. The broadband time-domain digital beamforming method based on digital intermediate frequency integer sampling period delay according to claim 1 is characterized in that: The received signal satisfies: x0(t)=Arect(t / T1)cos(2πft); x i (t)=Arect((t+τ) / T1)cos(2πf(t+τ)); Where x0(t) is the received signal of the reference array element at time t, A is the amplitude of the signal, rect(t / T1) represents the pulse signal with a pulse width of T1, f is the frequency, and x i (t) is the received signal of the i-th array element at time t, i=1,…,N-1, d is the array element spacing, θ is the incident azimuth, and c is the speed of light.

4. The broadband time-domain digital beamforming method based on digital intermediate frequency integer sampling period delay according to claim 1 is characterized in that: The method for obtaining the carrier frequency estimation value of the received signal of each array element includes: Detecting the received signal of each array element and estimating the carrier frequency parameters to obtain a carrier frequency estimation value; Performing a down-conversion operation on the received signal according to the carrier frequency estimation value to obtain a down-converted signal; The down-converted signal is input into a digital low-pass filter to obtain a digital intermediate frequency signal.

5. The broadband time-domain digital beamforming method based on digital intermediate frequency integer sampling period delay according to claim 4 is characterized in that: The down-converted signal satisfies: in is the down-converted signal of the ith array element at time t, is the estimated value of carrier frequency.

6. The broadband time-domain digital beamforming method based on digital intermediate frequency integer sampling period delay according to claim 1 is characterized in that: The method for obtaining a target phase difference of a first array element relative to a reference array element includes: According to the down-converted signal of each array element, a corresponding relationship between the down-converted signal of each array element and the down-converted signal of the reference array element is obtained; According to the corresponding relationship, an expression for the phase difference of each array element relative to the reference array element is obtained; Decomposing a first expression of a target phase difference of the first array element relative to the reference array element to obtain a second expression including a carrier frequency estimation value and a time delay; The second expression is solved according to the carrier frequency estimation value and the time delay to obtain a target phase difference of the first array element relative to the reference array element.

7. The broadband time-domain digital beamforming method based on digital intermediate frequency integer sampling period delay according to claim 1 is characterized in that: The delayed digital intermediate frequency signal satisfies: Among them, n i =min{iτ-n i Δt} represents the number of sampling points corresponding to the minimum delay error of the i-th channel.

8. A broadband time-domain digital beamforming device based on digital intermediate frequency integer sampling period delay, characterized in that: include: A signal receiving module, used to receive a broadband signal according to a signal receiving model of a uniform linear array to obtain a received signal; A digital intermediate frequency signal module is used to perform down-conversion and filtering operations on the received signal of each array element according to the carrier frequency estimation value of the received signal of each array element to obtain a digital intermediate frequency signal of each array element; A phase compensation module, used to perform phase compensation on the digital intermediate frequency signal of each array element according to the target phase difference of the first array element relative to the reference array element, so as to obtain a compensated digital intermediate frequency signal of each array element; A time delay processing module is used to perform time delay processing on the compensated digital intermediate frequency signal of each array element according to the sampling period to obtain a delayed digital intermediate frequency signal of each array element; The broadband signal beam module is used to obtain a broadband signal beam according to the delayed digital intermediate frequency signal of each array element.

9. An electronic device, characterized in that: include: Memory, processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory, so that the processor performs the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, which are used to implement the method according to any one of claims 1 to 7 when executed by a processor.

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