FPGA-based digital beamforming system

Abstract

This invention discloses an FPGA-based digital beamforming system. The system includes: multiple sampling boards, a beamforming board, a main control board, and an optical fiber output board. Each sampling board includes a first sampling module and a second sampling module, and the beamforming board includes a first beamforming module and a second beamforming module. The first sampling module is used to determine several compressed frequency domain data based on analog signals from several antennas participating in beamforming, and then sends the compressed frequency domain data to the first beamforming module. This invention solves the technical problems of existing beamforming systems, such as low computational resource requirements, slow speed, poor flexibility, and poor scalability.

Description

Technical Field

[0001] This invention relates to the field of radar signal processing technology, and more specifically, to a digital beamforming system based on FPGA. Background Technology

[0002] Beamforming technology, a key component of multi-functional phased array radar, is a significant feature that distinguishes digital signal processing in multi-functional phased array detection systems from signal processing in traditional mechanically scanned antenna detection systems. Digital beamforming (DBF) uses digital processing methods to synthesize the spatial energy of antenna beams. Traditional phased array systems typically use phase shifters for phase compensation to achieve beamforming in the desired signal direction. However, using programmable digital processing methods allows the entire phased array system to arbitrarily and rapidly switch antenna beam scanning positions during operation. The main function of the digital beamformer is to digitally beamform the signals received by different antenna elements, thereby obtaining estimates of relevant parameters such as the DOA (Directivity of Atmosphere) of the radiation source target signal, making it a core part of the entire system. Digital beamforming technology uses a digital processor to form the antenna beam, preserving the radiation source information contained in the signals received by each antenna array element. Furthermore, thanks to the flexibility of digital signal processing, it can achieve super-resolution and low sidelobe beam performance. The processing algorithms, software, and hardware platforms used in digital beamforming determine the antenna pattern and direction-finding performance of the beamformed antenna. Passive detection systems for detecting and monitoring radiation source signals from highly mobile targets require high real-time data processing capabilities. They need to employ high-speed DSPs or even multiple FPGAs for high-speed array processing to achieve rapid interception and tracking of radiation source targets. Summary of the Invention

[0003] This invention provides an FPGA-based digital beamforming system to at least solve the technical problems of existing beamforming systems, such as low computational resource requirements, slow speed, poor flexibility, and poor scalability.

[0004] According to one aspect of the present invention, an FPGA-based digital beamforming system is provided. The system may include: multiple sampling boards, a beamforming board, a main control board, and an optical fiber output board; wherein each sampling board includes a first sampling module and a second sampling module, and the beamforming board includes a first beamforming module and a second beamforming module; the first sampling module is used to determine a plurality of compressed frequency domain data based on a plurality of analog signals from antennas participating in beamforming, and to send the plurality of compressed frequency domain data to the first beamforming module; the first beamforming module is used to acquire the plurality of compressed frequency domain data from each sampling board, and based on the plurality of compressed frequency domain data from each sampling board, to obtain each initial frequency domain data of each sampling board, and simultaneously calculate the target time difference between the compressed frequency domain data of different sampling boards; and to send the target time difference to the second sampling module, and to convert each initial frequency domain data of each sampling board into a single compressed frequency domain data. The first sampling module sends the frequency domain data to the second beamforming module; the second sampling module sends several compressed frequency domain data from each sampling board to the second beamforming module based on the target time difference; the main control board sends the initial coefficient matrix to the second beamforming module; the second beamforming module determines each final compressed beam data of each beamforming board based on each initial frequency domain data and initial coefficient matrix of each sampling board, and sends it to the fiber optic output board; the fiber optic output board decompresses and aligns each final compressed beam data of each beamforming board to obtain each final beam data of each beamforming board, and performs an inverse Fourier transform on each final beam data of each beamforming board to obtain the target time domain signal of several antenna analog signals corresponding to all sampling boards.

[0005] Optionally, determining several compressed frequency domain data based on several antenna analog signals participating in beamforming includes: determining each initial frequency domain data based on each antenna analog signal; and determining each compressed frequency domain data based on each initial frequency domain data.

[0006] Optionally, determining each initial frequency domain data based on each of the several antenna analog signals includes: sampling each antenna analog signal to obtain each digital signal corresponding to each antenna analog signal; and performing a Fourier transform on each digital signal to obtain each initial frequency domain data.

[0007] Optionally, determining each compressed frequency domain data based on each initial frequency domain data includes: compressing each initial frequency domain data to obtain each compressed frequency domain data.

[0008] Optionally, obtaining each initial frequency domain data of each sampling board based on several compressed frequency domain data of each sampling board includes: splitting several compressed frequency domain data of each sampling board to obtain each compressed frequency domain data of each sample; and decompressing each compressed frequency domain data of each sample to obtain each initial frequency domain data of each sampling board.

[0009] Optionally, determining each final compressed beam data of each beamforming board based on each initial frequency domain data and initial coefficient matrix of each sampling board includes: obtaining each initial beam based on each initial frequency domain data and initial coefficient matrix; taking any initial beam as the target beam; multiplying the target beam by each of the remaining initial beams except the target beam to obtain each preset beam except the target beam; obtaining a target coefficient matrix based on each preset beam and the target beam; obtaining each final beam data based on the target coefficient matrix and each initial frequency domain data; and compressing each final beam data to obtain each final compressed beam data.

[0010] The beneficial effects of this invention are:

[0011] This invention proposes an FPGA-based digital beamforming system. This system can receive multiple frequency domain data from different sampling boards through a single beamforming board, realizing digital multi-beam generation. It can reduce the data transmission bandwidth and computing resource requirements of a single module and is feasible for engineering implementation. It can synthesize different types of frequency domain data from different sampling boards onto different beamforming boards, or synthesize the same type of frequency domain data from different sampling boards onto the same sampling board, providing optional data distribution methods to meet different beamforming scales and hardware resource requirements, and possessing flexibility and scalability for engineering implementation. Attached Figure Description

[0012] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0013] Figure 1 This is a schematic diagram of an FPGA-based digital beamforming system according to an embodiment of the present invention. Detailed Implementation

[0014] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0015] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0016] Example 1

[0017] According to embodiments of the present invention, an FPGA-based digital beamforming system is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system containing at least one set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0018] Figure 1 This is a schematic diagram of an FPGA-based digital beamforming system according to an embodiment of the present invention, such as... Figure 1 As shown, an FPGA-based digital beamforming system may include: multiple sampling boards, a beamforming board, a main control board, and an optical fiber output board; wherein, the sampling board includes a first sampling module and a second sampling module, and the beamforming board includes a first beamforming module and a second beamforming module.

[0019] The first sampling module is used to determine several compressed frequency domain data based on several antenna analog signals participating in beamforming, and send the several compressed frequency domain data to the first beamforming module.

[0020] Specifically, the analog signals of several antennas involved in beamforming are processed to obtain each compressed frequency domain data corresponding to each analog antenna signal, and the compressed frequency domain data is sent to the first beamforming module.

[0021] The first beamforming module is used to acquire several compressed frequency domain data from each sampling board, obtain each initial frequency domain data of each sampling board based on the several compressed frequency domain data of each sampling board, and calculate the target time difference between the compressed frequency domain data of different sampling boards; send the target time difference to the second sampling module, and send each initial frequency domain data of each sampling board to the second beamforming module.

[0022] Specifically, several compressed frequency domain data points are acquired from each sampling board. Based on these compressed frequency domain data points, initial frequency domain data points for each sampling board are obtained. Simultaneously, the target time difference between the compressed frequency domain data points of different sampling boards is calculated. For example, the first sampling board sends several compressed frequency domain data points to the first beamforming board, which then times the data. At the 5th second, the second sampling board sends several compressed frequency domain data points to the first beamforming board. Therefore, the target time is 5 seconds, and the 5-second time is sent to the second sampling module of the first sampling board. Each beamforming board can receive the same type of data from different sampling boards, or the same type of data from different sampling boards.

[0023] The second sampling module is used to send several compressed frequency domain data of each sampling board to the second beamforming module based on the target time difference.

[0024] Specifically, when the second sampling board sends several compressed frequency domain data at the next moment based on the target time difference, it will send them 5 seconds later.

[0025] The main control board is used to send the initial coefficient matrix to the second beamforming module.

[0026] Specifically, the user designs an initial coefficient matrix and sends the initial coefficient matrix to the second beamforming unit.

[0027] The second beamforming module is used to determine each final compressed beam data of each beamforming board based on each initial frequency domain data and initial coefficient matrix of each sampling board, and send it to the fiber output board.

[0028] Specifically, each initial frequency domain data and initial coefficient matrix of each sampling board is processed to obtain each final compressed beam data of each beamforming board.

[0029] The fiber optic output board is used to decompress and align each final compressed beam data of each beamforming board to obtain each final beam data of each beamforming board. The inverse Fourier transform is then performed on each final beam data of each beamforming board to obtain the target time domain signal of several antenna analog signals corresponding to all sampling boards.

[0030] Specifically, each final compressed beam data of each beamforming board is decompressed and aligned to obtain each final beam data of each beamforming board. Then, each final beam data of each beamforming board is subjected to inverse Fourier transform to obtain the target time domain signal of several antenna analog signals corresponding to all sampling boards.

[0031] The system described in this embodiment will be further described below.

[0032] As an optional embodiment, determining several compressed frequency domain data based on several antenna analog signals participating in beamforming includes: determining each initial frequency domain data based on each antenna analog signal; and determining each compressed frequency domain data based on each initial frequency domain data.

[0033] In this embodiment, each of the several antenna analog signals is processed to obtain each initial frequency domain data; each initial frequency domain data is processed to obtain each compressed frequency domain data.

[0034] As an optional embodiment, determining each initial frequency domain data based on each of the several antenna analog signals includes: sampling each antenna analog signal to obtain each digital signal corresponding to each antenna analog signal; and performing a Fourier transform on each digital signal to obtain each initial frequency domain data.

[0035] In this embodiment, each antenna analog signal is sampled to obtain each digital signal corresponding to each antenna analog signal; each digital signal is subjected to Fourier transform to obtain each initial frequency domain data.

[0036] As an optional embodiment, determining each compressed frequency domain data based on each initial frequency domain data includes: compressing each initial frequency domain data to obtain each compressed frequency domain data.

[0037] In this embodiment, each initial frequency domain data is compressed to obtain each compressed frequency domain data.

[0038] As an optional embodiment, obtaining each initial frequency domain data of each sampling board based on several compressed frequency domain data of each sampling board includes: splitting several compressed frequency domain data of each sampling board to obtain each compressed frequency domain data of each sample; and decompressing each compressed frequency domain data of each sample to obtain each initial frequency domain data of each sampling board.

[0039] In this embodiment, several compressed frequency domain data of each sampling board are split to obtain each compressed frequency domain data of each sample; each compressed frequency domain data of each sample is decompressed to obtain each initial frequency domain data of each sampling board.

[0040] As an optional embodiment, determining each final compressed beam data of each beamforming board based on each initial frequency domain data and initial coefficient matrix of each sampling board includes: obtaining each initial beam based on each initial frequency domain data and initial coefficient matrix; taking any initial beam as a target beam; multiplying the target beam by each of the remaining initial beams except the target beam to obtain each preset beam except the target beam; obtaining a target coefficient matrix based on each preset beam and the target beam; obtaining each final beam data based on the target coefficient matrix and each initial frequency domain data; and compressing each final beam data to obtain each final compressed beam data.

[0041] In this embodiment, each initial frequency domain data and initial coefficient matrix are multiplied to obtain each initial beam; any initial beam is taken as the target beam; the target beam is multiplied by each of the remaining initial beams except the target beam to obtain each preset beam except the target beam; each preset beam and the target beam are substituted into... The target coefficient matrix is ​​obtained, where, For each preset beam and target beam, multiply the target coefficient matrix with each initial frequency domain data to obtain each final beam data; compress each final beam data to obtain each final compressed beam data.

[0042] As an optional embodiment, obtaining each initial beam based on each initial frequency domain data and the initial coefficient matrix includes: determining each initial beam by the product of each initial frequency domain data and the initial coefficient matrix.

[0043] As an optional embodiment, obtaining each final beam data based on the target coefficient matrix and each initial frequency domain data includes: determining each final beam data by the product between the target coefficient matrix and each initial frequency domain data.

[0044] In this embodiment of the invention, a first sampling module is used to determine several compressed frequency domain data based on several analog signals from several antennas participating in beamforming, and send these compressed frequency domain data to a first beamforming module. Each compressed frequency domain data carries a time stamp. The first beamforming module is used to acquire several compressed frequency domain data from each sampling board, and based on these data, obtain each initial frequency domain data for each sampling board, while simultaneously calculating the target time difference between the compressed frequency domain data from different sampling boards. The target time difference is then sent to a second sampling module, which sends each initial frequency domain data from each sampling board to the second beamforming module. The second sampling module is used to send several compressed frequency domain data from each sampling board to the second beamforming module based on the target time difference. A main control board is used to send an initial coefficient matrix to the second beamforming module. The second beamforming module is used to determine each final compressed beam data for each beamforming board based on each initial frequency domain data and the initial coefficient matrix from each sampling board. The data is then sent to the fiber optic output board. The fiber optic output board is used to decompress and align each final compressed beam data of each beamforming board to obtain each final beam data of each beamforming board. An inverse Fourier transform is performed on each final beam data of each beamforming board to obtain the target time-domain signal of several antenna analog signals corresponding to all sampling boards. This solves the technical problems of existing beamforming systems, such as low computational resource requirements, slow speed, poor flexibility, and poor scalability. It achieves the goal of a single beamforming board receiving several frequency domain data from different sampling boards, realizing digital multi-beam generation. This reduces the data transmission bandwidth and computational resource requirements of a single module, making it feasible for engineering implementation. It can synthesize different types of frequency domain data from different sampling boards onto different beamforming boards, or synthesize the same type of frequency domain data from different sampling boards onto the same sampling board, providing optional data distribution methods to meet different beamforming scales and hardware resources, demonstrating technical effects of flexibility and scalability in engineering implementation.

[0045] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0046] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0047] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some interfaces; indirect couplings or communication connections between units or modules may be electrical or other forms.

[0048] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

Claims

1. A digital beamforming system based on FPGA, characterized in that, The system includes: multiple sampling boards, a beamforming board, a main control board, and an optical fiber output board; wherein, the sampling board includes a first sampling module and a second sampling module, and the beamforming board includes a first beamforming module and a second beamforming module; The first sampling module is used to determine several compressed frequency domain data based on several antenna analog signals participating in beamforming, and send the several compressed frequency domain data to the first beamforming module. The first beamforming module is used to acquire several compressed frequency domain data from each sampling board, and based on the several compressed frequency domain data from each sampling board, to obtain each initial frequency domain data of each sampling board. At the same time, it calculates the target time difference between the compressed frequency domain data of different sampling boards and sends the target time difference to the second sampling module. When the second sampling board sends several compressed frequency domain data according to the target time difference at the next moment, it will delay the transmission of the target time difference and send each initial frequency domain data of each sampling board to the second beamforming module. The second sampling module is used to send several compressed frequency domain data of each sampling board to the second beamforming module based on the target time difference; The main control board is used to send the initial coefficient matrix to the second beamforming module; The second beamforming module is used to determine each final compressed beam data of each beamforming board based on each initial frequency domain data and initial coefficient matrix of each sampling board, and send it to the fiber output board. The fiber optic output board is used to decompress and align each final compressed beam data of each beamforming board to obtain each final beam data of each beamforming board. Then, an inverse Fourier transform is performed on each final beam data of each beamforming board to obtain the target time domain signal of several antenna analog signals corresponding to all sampling boards.

2. The FPGA-based digital beamforming system according to claim 1, characterized in that, The determination of several compressed frequency domain data based on several antenna analog signals participating in beamforming includes: Each initial frequency domain data is determined based on each of the several antenna analog signals; Each compressed frequency domain data is determined based on each initial frequency domain data.

3. The FPGA-based digital beamforming system according to claim 2, characterized in that, The determination of each initial frequency domain data based on each of several antenna analog signals includes: Each antenna analog signal is sampled to obtain each digital signal corresponding to each antenna analog signal; Perform a Fourier transform on each digital signal to obtain each initial frequency domain data.

4. The FPGA-based digital beamforming system according to claim 2, characterized in that, The process of determining each compressed frequency domain data based on each initial frequency domain data includes: Each initial frequency domain data is compressed to obtain each compressed frequency domain data.

5. The FPGA-based digital beamforming system according to claim 1, characterized in that, The process of obtaining each initial frequency domain data for each sampling board based on several compressed frequency domain data for each sampling board includes: The compressed frequency domain data of each sampling board are split into several compressed frequency domain data of each sample; Each sampled compressed frequency domain data is decompressed to obtain each initial frequency domain data of each sampling board.

6. The FPGA-based digital beamforming system according to claim 1, characterized in that, The determination of each final compressed beam data for each beamforming board based on each initial frequency domain data and initial coefficient matrix of each sampling board includes: Each initial beam is obtained based on each initial frequency domain data and initial coefficient matrix; Use any initial beam as the target beam; Multiply the target beam by each of the other initial beams except the target beam to obtain each preset beam except the target beam. Based on each preset beam and target beam, the target coefficient matrix is ​​obtained; Based on the target coefficient matrix and each initial frequency domain data, each final beam data is obtained; Each final beam data is compressed to obtain each final compressed beam data.

7. The FPGA-based digital beamforming system according to claim 6, characterized in that, The process of obtaining each initial beam based on each initial frequency domain data and initial coefficient matrix includes: The product of each initial frequency domain data and the initial coefficient matrix is ​​used to determine each initial beam.

8. The FPGA-based digital beamforming system according to claim 6, characterized in that, The process of obtaining each final beam data based on the target coefficient matrix and each initial frequency domain data includes: The product of the target coefficient matrix and each initial frequency domain data is used to determine each final beam data.

9. A computer system, characterized in that... include: One or more processors, a computer-readable storage medium for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors cause the one or more processors to implement the system of claim 1.

10. A computer-readable storage medium, characterized in that... The system contains computer-executable instructions that, when executed, implement the system of claim 1.

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