A digital beam forming device based on a serial structure

Abstract

A serial-structured digital beamforming device, belonging to the field of radar communication technology, solves the problems of traditional multi-level tree-structured digital beamforming devices, such as numerous types of digital beamforming hardware boards, high cost, difficult operation and maintenance, and low reliability. By connecting multiple second beamforming units end-to-end in a serial structure, the number of digital beamforming boards is reduced, as are the large amounts of long-distance trans-cabin digital optical fibers used to transmit intermediate data between the boards, thus reducing costs, greatly improving reliability, and simplifying system use and maintenance. By setting a two-to-one switch to bypass a faulty second beamforming unit, only the signal synthesis gain of the faulty subarray antenna unit is lost, without significantly affecting the overall gain of the device, further improving the reliability of the serial structure.

Description

Technical Field

[0001] This invention belongs to the field of radar communication technology and relates to a digital beamforming device based on a serial structure. Background Technology

[0002] Large-scale antenna arrays often employ digital beamforming (DBF) technology to achieve more receive or transmit beams. As the number of antenna elements used in large-aperture arrays increases, the computational complexity of beamforming also increases. Digital beamforming technology is generally implemented based on real-time logic operations in digital circuits, involving weighting, phase shifting, delaying, and summing of the array element signals. Its hardware is mostly based on FPGAs or ASICs, offering good real-time performance and scalability.

[0003] When the array size is large, due to the limited computing power and number of interfaces of a single FPGA or ASIC digital board, traditional solutions often employ a multi-level processing architecture. This involves dividing multiple array signals into M groups (subarrays), with each group undergoing cell-level array computation using a first-level DBF board. The computation results are then transmitted to a second-level DBF board for subarray-level array computation, and so on. Figure 5 As shown, the digital beamforming (DBF) processing of the entire array is completed through a multi-level tree-like parallel structure. Furthermore, since the first-level and subsequent DBF boards are often deployed in different locations—the first-level DBF board is often close to the antenna elements and deployed outdoors, while the second-level and subsequent DBF boards are generally deployed in shelters—data transmission between the first-level and subsequent DBF boards typically requires numerous fiber optic cables penetrating the shelter, resulting in high costs and a large workload for on-site installation and subsequent maintenance. Traditional multi-level parallel DBF processing methods have the following limitations: 1) At least two types of boards are required; the first-level boards, due to the inclusion of digital-to-analog converter chips, differ from other levels; 2) A large amount of digital fiber optic cable is needed between the first-level and second-level boards for transmitting intermediate data; 3) The failure of a higher-level processing board has a greater impact on the system. Summary of the Invention

[0004] The purpose of this invention is to solve the problems of traditional multi-level tree-structured digital beamforming devices, such as the large number of digital beamforming hardware board types, high cost, high operation and maintenance difficulty, and low reliability.

[0005] The present invention solves the above-mentioned technical problems through the following technical solutions:

[0006] A digital beamforming device based on a serial structure includes: M antenna subarrays (10), M first beamforming units (11), and (M-1) second beamforming units (12); the M antenna subarrays (10) are respectively connected to the M first beamforming units (11); the (M-1) second beamforming units (12) are connected in series to form a serial structure, that is, the first three beamforming units (12) of the previous second beamforming unit (12) are connected in series. # The output end and the next second beamforming unit (12) 1 # The input terminal is connected to the first second beamforming unit (12) in the serial structure. # The input terminal is connected to the output terminal of the first antenna subarray (10), and the (M-1) second beamforming units (12) are connected to each other. # The input terminals are respectively connected to the output terminals of the second to the Mth first beamforming units (11); the first beamforming unit (11) is used to beamform the signal output by the antenna subarray (10), and the second beamforming unit (12) is used to serially beamform the signals output by multiple first beamforming units (11).

[0007] Furthermore, each of the first beamforming units (11) includes: an analog-to-digital conversion module (111) and a first beamforming module (112); one end of the analog-to-digital conversion module (111) is connected to the antenna subarray (10), the other end of the analog-to-digital conversion module (111) is connected to one end of the first beamforming module (112), and the other end of the first beamforming module (112) is connected to the input end of the second beamforming unit (12).

[0008] Further, the second beamforming unit (12) includes: a delay module (121), a photoelectric conversion module (122), an electro-optical conversion module (123), a second beamforming module (124), a first two-to-one switch (125), and a second two-to-one switch (126); the b-end of the first two-to-one switch (125) is connected to the input end of the photoelectric conversion module (122), and the output end of the photoelectric conversion module (122) is connected to one input end of the second beamforming module (124). The output of the delay module (121) is connected to another input of the second beamforming module (124). The output of the second beamforming module (124) is connected to the input of the electro-optic conversion module (123). The output of the electro-optic conversion module (123) is connected to the b terminal of the second two-way switch (126). The c terminal of the first two-way switch (125) is connected to the c terminal of the second two-way switch (126). The a terminal of the first two-way switch (125) serves as the 1 terminal of the second beamforming unit (12). #The input terminal of the delay module (121) serves as the second beamforming unit (12). # The input terminal, the a-end of the second two-to-one switch (126), serves as the 3rd input terminal of the second beamforming unit (12). # Output terminal.

[0009] Furthermore, the working process of the device is as follows: each antenna subarray (10) transmits the received signal to the corresponding first beamforming unit (11). The signal is converted from analog to digital by the analog-to-digital converter (111), and then beamformed by the first beamforming module (112). The beamforming signal output from the first first beamforming unit (11) is input to the first second beamforming unit (12). # The beamforming signals output from the 2nd to Mth first beamforming units (11) are respectively input to the (M-1) second beamforming units (12). # Input: The beamforming signal input to each second beamforming unit (12) is delayed by the corresponding delay module (121), and then beamformed again by the signal output from the previous second beamforming unit (12) through the second beamforming module (124). The beamforming is sequentially beamformed until the final beamforming signal is output.

[0010] In one embodiment, the analog-to-digital conversion module (111) is implemented using an A / D chip, which is used to convert analog quantities into digital quantities.

[0011] In one embodiment, the first beamforming module (112) and the second beamforming module (124) are implemented using an FPGA or ASIC chip, which is used for beamforming.

[0012] The advantages of this invention are:

[0013] (1) The digital beamforming device based on the serial structure of the present invention forms a serial structure by connecting multiple second beamforming units (12) in series from end to end, which reduces the types of digital beamforming boards. There is only one type of DBF board, and no second-level and third-level DBF boards are used. This reduces the types and number of boards, unifies the beamforming board model, and greatly reduces the production cost and future performance upgrade cost of the device.

[0014] (2) In traditional multi-level tree architecture, digital signals are transmitted between the first-level DBF board and the second-level DBF board through multiple long optical fibers; while the digital beamforming device based on serial structure of the present invention reduces the large number of long-distance through-cabin digital optical fibers used to transmit intermediate data between the first-level DBF board and the second-level DBF board, thereby reducing costs, greatly improving reliability, and reducing the difficulty of system use and operation and maintenance.

[0015] (3) By setting the first two-to-one switch (125) and the second two-to-one switch (126), the faulty second beamforming unit (12) is bypassed, and only the signal synthesis gain of the faulty subarray antenna unit is lost. This will not have a significant impact on the gain of the device, thus improving the reliability of the serial structure.

[0016] (4) The reliability of traditional multi-level tree architecture depends on the effectiveness of high-level DBF boards. The digital beamforming device based on serial structure of the present invention significantly improves the system reliability by reducing its dependence on high-level processing boards, and the reliability is significantly improved. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the architecture of the digital beamforming device based on a serial structure according to Embodiment 1 of the present invention;

[0018] Figure 2 This is a schematic diagram of the structure of the second beam combining unit of the digital beamforming device based on a serial structure according to Embodiment 1 of the present invention;

[0019] Figure 3 This is a schematic diagram of the signal arriving at the antenna element of the digital beamforming device based on a serial structure according to Embodiment 1 of the present invention;

[0020] Figure 4 This is a schematic diagram of the basic beamforming process of the digital beamforming device based on a serial structure in Embodiment 1 of the present invention;

[0021] Figure 5 This is a schematic diagram of the architecture of a traditional multi-level tree-structured digital beamforming device, as shown in Comparative Example 1. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0024] Example 1

[0025] like Figure 1 As shown, the serial-structure-based digital beamforming apparatus of this embodiment will be described in detail using antenna signal reception as an example. The apparatus of this embodiment is also applicable to the case of antenna signal transmission. The serial-structure-based digital beamforming apparatus of this embodiment includes: M antenna subarrays (10), M first beamforming units (11), and (M-1) second beamforming units (12).

[0026] Each antenna subarray (10) includes K antenna elements, and M antenna subarrays (10) constitute a large-aperture array antenna; the M antenna subarrays (10) are respectively connected to M first beamforming units (11); (M-1) second beamforming units (12) are connected in series to form a serial structure, that is, the first second beamforming unit (12) has 3 # The output end and the next second beamforming unit (12) 1 # The input terminal is connected to the first second beamforming unit (12) in the serial structure. # The input terminal is connected to the output terminal of the first antenna subarray (10), and the (M-1) second beamforming units (12) are connected to each other. # The input terminals are respectively connected to the output terminals of the 2nd to Mth first beamforming units (11). The first beamforming unit (11) is used to beamform the signal output by the antenna subarray (10), and the second beamforming unit (12) is used to serially beamform the signals output by multiple first beamforming units (11).

[0027] Each of the first beamforming units (11) includes: an analog-to-digital conversion module (111) and a first beamforming module (112); one end of the analog-to-digital conversion module (111) is connected to the antenna subarray (10), the other end of the analog-to-digital conversion module (111) is connected to one end of the first beamforming module (112), and the other end of the first beamforming module (112) is connected to the input end of the second beamforming unit (12).

[0028] like Figure 2As shown, the second beamforming unit (12) includes: a delay module (121), a photoelectric conversion module (122), an electro-optical conversion module (123), a second beamforming module (124), a first two-to-one switch (125), and a second two-to-one switch (126); the b-end of the first two-to-one switch (125) is connected to the input end of the photoelectric conversion module (122), and the output end of the photoelectric conversion module (122) is connected to one input end of the second beamforming module (124). The output of the delay module (121) is connected to another input of the second beamforming module (124). The output of the second beamforming module (124) is connected to the input of the electro-optic conversion module (123). The output of the electro-optic conversion module (123) is connected to the b terminal of the second two-way switch (126). The c terminal of the first two-way switch (125) is connected to the c terminal of the second two-way switch (126). The a terminal of the first two-way switch (125) serves as the 1 terminal of the second beamforming unit (12). # The input terminal of the delay module (121) serves as the second beamforming unit (12). # The input terminal, the a-end of the second two-to-one switch (126), serves as the 3rd input terminal of the second beamforming unit (12). # Output terminal.

[0029] The first beamforming unit (11) is implemented using a DBF board, which integrates an A / D chip and an FPGA or ASIC chip; wherein the A / D chip is used to convert analog quantities into digital quantities, and the FPGA or ASIC chip is used for preliminary beamforming.

[0030] The device's workflow is as follows:

[0031] Each antenna subarray (10) transmits the received signal to the corresponding first beamforming unit (11). The signal is converted from analog to digital by the analog-to-digital converter (111), and then undergoes preliminary beamforming by the first beamforming module (112). The preliminary beamforming signal output from the output of the first first beamforming unit (11) is input to the first second beamforming unit (12). # The preliminary beamforming signals output from the 2nd to Mth first beamforming units (11) are respectively input to the (M-1) second beamforming units (12). # Input: The initial beamforming signal input to each second beamforming unit (12) is delayed by the corresponding delay module (121), and then beamformed again by the signal output from the previous second beamforming unit (12) through the second beamforming module (124). The beamforming is sequentially performed until the final beamforming signal is output.

[0032] like Figure 2 As shown, the purpose of setting the first two-to-one switch (125) and the second two-to-one switch (126) is to improve the reliability of the serial structure. When one or more second beamforming units (12) of the serial structure fail, both the first two-to-one switch (125) and the second two-to-one switch (126) are switched to the c end, bypassing the faulty second beamforming unit (12). The signal output by the second beamforming unit (12) before the faulty second beamforming unit (12) is directly input into the second beamforming unit (12) after the faulty second beamforming unit (12) for beamforming. Therefore, when the second beamforming unit (12) fails, only the signal combining gain of the faulty subarray antenna unit is lost, and it will not have a significant impact on the gain of the device.

[0033] like Figure 3 , Figure 4 As shown, the basic principle of beamforming is that different antenna elements receive signals with different delays, and there is a phase difference between the signals due to the delay. During beamforming, phase difference correction is performed, and the signals of multiple antenna elements are superimposed in phase.

[0034] Comparative Example 1

[0035] The following is a comparison between the serial-structure-based digital beamforming device of Example 1 and the traditional multi-level tree architecture:

[0036] like Figure 5 As shown, this is a traditional multi-level tree architecture. The received signals from the K antenna elements of each subarray outside the cabin are converted from analog to digital and preliminarily beamformed by the first-level DBF board. The preliminarily synthesized signal is then transmitted to the second-level DBF board inside the cabin through multiple long optical fibers. After the second-level DBF board performs the synthesis operation, it is transmitted to the third-level DBF board through a short optical fiber. Finally, a beamformed signal is sent to the signal processing board at the back end.

[0037] The comparison shows that:

[0038] (1) The serial structure-based digital beamforming device in Example 1 has only one type of DBF board and does not use second-level and third-level DBF boards, which reduces the types and number of boards, unifies the beamforming board model, and greatly reduces the production cost and future performance upgrade cost of the device.

[0039] (2) In the traditional multi-level tree architecture, digital signals are transmitted between the first-level DBF board and the second-level DBF board through multiple long optical fibers; while the digital beamforming device based on serial structure in Example 1 reduces the large number of long-distance through-cabin digital optical fibers used to transmit intermediate data between the first-level DBF board and the second-level DBF board, reducing costs, greatly improving reliability, and reducing the difficulty of system use and operation and maintenance.

[0040] (3) The reliability of traditional multi-level tree architecture depends on the effectiveness of high-level DBF boards. The digital beamforming device based on serial structure in Example 1 significantly improves the system reliability's dependence on high-level processing boards. Each DBF board can be bypassed independently, resulting in a significant improvement in reliability.

[0041] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A digital beamforming device based on a serial structure, characterized in that, include: M antenna subarrays (10), M first beamforming units (11), and (M-1) second beamforming units (12); the M antenna subarrays (10) are respectively connected to the M first beamforming units (11); the (M-1) second beamforming units (12) are connected in series to form a serial structure, that is, the first second beamforming unit (12) has 3... # The output end and the next second beamforming unit (12) 1 # The input terminal is connected to the first second beamforming unit (12) in the serial structure. # The input terminal is connected to the output terminal of the first antenna subarray (10), and the (M-1) second beamforming units (12) are connected to the output terminal of the second antenna subarray (10). # The input terminals are respectively connected to the output terminals of the second to the Mth first beamforming units (11); the first beamforming unit (11) is used to beamform the signal output by the antenna subarray (10), and the second beamforming unit (12) is used to serially beamform the signals output by multiple first beamforming units (11). Each of the first beamforming units (11) includes: an analog-to-digital conversion module (111) and a first beamforming module (112); one end of the analog-to-digital conversion module (111) is connected to the antenna subarray (10), the other end of the analog-to-digital conversion module (111) is connected to one end of the first beamforming module (112), and the other end of the first beamforming module (112) is connected to the input end of the second beamforming unit (12); The second beamforming unit (12) includes: a delay module (121), a photoelectric conversion module (122), an electro-optical conversion module (123), a second beamforming module (124), a first two-to-one switch (125), and a second two-to-one switch (126); the b-end of the first two-to-one switch (125) is connected to the input end of the photoelectric conversion module (122), and the output end of the photoelectric conversion module (122) is connected to one input end of the second beamforming module (124). The output of module (121) is connected to another input of the second beamforming module (124). The output of the second beamforming module (124) is connected to the input of the electro-optical conversion module (123). The output of the electro-optical conversion module (123) is connected to the b end of the second two-to-one switch (126). The c end of the first two-to-one switch (125) is connected to the c end of the second two-to-one switch (126). The a end of the first two-to-one switch (125) serves as the 1 of the second beamforming unit (12). # The input terminal of the delay module (121) serves as the second beamforming unit (12). # The input terminal, the a-end of the second two-to-one switch (126), serves as the 3rd input terminal of the second beamforming unit (12). # Output terminal.

2. The digital beamforming apparatus based on a serial structure according to claim 1, characterized in that, The working process of the device is as follows: Each antenna subarray (10) transmits the received signal to the corresponding first beamforming unit (11). The signal is converted from analog to digital by the analog-to-digital converter (111), and then beamformed by the first beamforming module (112). The beamforming signal output from the first first beamforming unit (11) is input to the first second beamforming unit (12). # The beamforming signals output from the 2nd to Mth first beamforming units (11) are respectively input to the (M-1) second beamforming units (12). # Input end; the beamforming signal input to each second beamforming unit (12) is delayed by the corresponding delay module (121), and then beamformed again by the signal output by the previous second beamforming unit (12) through the second beamforming module (124), and so on, until the final beamforming signal is output.

3. The digital beamforming apparatus based on a serial structure according to claim 1, characterized in that, The analog-to-digital conversion module (111) is implemented using an A / D chip, which is used to convert analog quantities into digital quantities.

4. The digital beamforming apparatus based on a serial structure according to claim 1, characterized in that, The first beamforming module (112) and the second beamforming module (124) are implemented using FPGA or ASIC chips, and the FPGA or ASIC chips are used for beamforming.

Images