Analog-digital beamforming system and method based on subarrays

Abstract

The application discloses a kind of analog-digital beam synthesis system and method based on subarray to solve the problems that true parallel multi-beam output cannot be realized and the hierarchical organization mode between subarray and array surface lacks unified optimization in prior art.The application divides antenna array surface into multiple antenna subarrays and beam subarrays by hierarchical analog beam synthesis structure, and combines at each level to finally form multiple independent analog beams.Finally, these analog beams can be converted from analog to digital in digital domain, thereby realizing the synthesis of analog-digital beams.Thus, the aforementioned hierarchical synthesis structure can realize true parallel multi-beam output, and this structure can also enable analog and digital parts to play to their strengths, thereby enabling analog pre-synthesis and digital processing to work together, and further enabling stable high-precision angle measurement in complex environments.Therefore, the application is very suitable for large-scale application and promotion.

Description

Technical Field

[0001] This invention belongs to the field of analog synthesized multibeam antenna technology, specifically relating to an analog digital beamforming system and method based on subarrays. Background Technology

[0002] Array antenna beamforming technology is one of the key technologies in modern radar systems, wireless communication systems and space exploration systems. Its core purpose is to improve the directional selectivity, signal-to-noise ratio and anti-interference capability of the system by weighted synthesis of the signals of each element of the array antenna. Depending on the domain in which the beamforming processing is performed, existing technologies are generally divided into three basic structures: analog beamforming, digital beamforming and analog-digital hybrid beamforming.

[0003] In all-digital beamforming technology, each array antenna element is equipped with an independent RF receiving link and a high-speed analog-to-digital converter. Beams are formed by applying amplitude and phase weights to the signals of each element in the digital domain. This structure offers extremely high flexibility and accuracy. However, as the array size increases, the number of required RF links and analog-to-digital converters increases dramatically, leading to a significant increase in system hardware cost, power consumption, and size. Consequently, it becomes difficult to meet the miniaturization and low-power requirements of engineering equipment.

[0004] Analog beamforming technology significantly reduces the number of back-end digital channels by introducing phase shifters, amplitude modulators, and power combiners at the radio frequency end, and by pre-weighting and combining multiple array element signals before they enter the analog-to-digital converter. However, traditional analog beamforming methods can usually only form a single or a small number of fixed beams, and their beam flexibility is low, making it difficult to simultaneously meet the needs of wide-area coverage and high-resolution directional detection.

[0005] In recent years, the proposed analog-digital hybrid beamforming technology has achieved a balance between system complexity and beam flexibility to some extent by dividing the array into multiple subarray units, performing pre-synthesis in the analog domain within the subarray, and further processing in the digital domain. However, existing subarray-level hybrid beamforming methods still have significant shortcomings: on the one hand, most schemes only form a single analog beam at the subarray level, failing to achieve true parallel multi-beam output, resulting in low utilization of system spatiotemporal resources; on the other hand, existing schemes lack unified optimization of the hierarchical organization between subarrays and array surfaces, and the coordination between analog pre-synthesis and back-end digital processing is insufficient, making it difficult to obtain stable angle measurement performance in complex environments.

[0006] Therefore, based on the aforementioned shortcomings, there is an urgent need to provide an analog-digital beamforming system that can achieve coordinated optimization of subarray-level parallel multi-beam analog synthesis and fine digital domain processing to meet the development needs of modern radar and communication systems. Summary of the Invention

[0007] The purpose of this invention is to provide an analog-digital beamforming system and method based on subarrays, in order to solve the problems of existing technologies that cannot achieve true parallel multi-beam output and lack unified optimization of the hierarchical organization between subarrays and array surfaces, resulting in insufficient synergy between analog pre-synthesis and back-end digital processing.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: Firstly, a subarray-based analog-to-digital beamforming system is provided, comprising: The beam subarray module is used to acquire the radio frequency signals of four array elements and, based on the radio frequency signals of the four array elements, combine and superimpose them to generate four independent first analog beam signals. The antenna subarray module includes several beam subarray modules, which are used to perform combining and superimposing processing on the first analog beam signals belonging to the same sequence number signal branch among the four first analog beam signals output by each beam subarray module according to the same path superposition rule, so as to generate four independent second analog beam signals. The antenna module includes four antenna subarray modules, which are used to output four second analog beam signals generated by each of the four antenna subarray modules to generate 16 independent actual analog beam signals to be transmitted to the downconversion processing module. The downconversion processing module is used to process the 16 actual analog beam signals generated by the antenna module to obtain 16 processed signals, wherein any processed signal is a downconverted signal or a baseband signal. The multi-channel analog-to-digital converter module is used to perform analog-to-digital conversion on 16 processed signals to output 16 digital signal sequences.

[0009] Based on the above disclosure, this invention uses a hierarchical analog beamforming structure to divide the antenna array into multiple subarrays (beam subarrays and antenna subarrays), and performs combining at each level. Specifically, at the beam subarray module, four independent first analog beam signals are generated through combining and superposition. Then, at the antenna subarray level, a co-channel superposition rule is used to combine and superimpose the first analog beam signals belonging to the same sequence signal branch from the four first analog beam signals generated by the included beam subarray modules to generate four independent second analog beam signals. Since the antenna array is constructed from four antenna subarrays, 16 independent actual analog beam signals can be output. Finally, these signals can be processed in the digital domain. Analog-to-digital conversion (i.e., synchronous analog-to-digital sampling) is performed on these analog beams to achieve analog-to-digital beam synthesis. Thus, the aforementioned hierarchical synthesis structure can achieve true parallel multi-beam output. This structure also allows the analog and digital parts to each leverage their respective advantages (the analog part reduces complexity, while the digital part provides flexibility and high precision). This enables analog pre-synthesis and digital processing to work collaboratively, thereby achieving stable and high-precision angle measurement in complex environments. Based on this, the present invention provides an analog-to-digital beam synthesis system that can achieve collaborative optimization of subarray-level parallel multi-beam analog synthesis and fine digital domain processing. It can meet the development needs of modern radar and communication systems and is therefore very suitable for large-scale application and promotion.

[0010] In one possible design, the beam subarray module includes: four array antenna elements, four multiplex phase amplitude modulation network elements, and four combiners; The output terminals of the four array antenna elements are each connected to a multi-channel phase amplitude modulation network unit, which is used to output the array element radio frequency signal to their respective multi-channel phase amplitude modulation network unit; Each multi-channel phase amplitude modulation network unit is used to divide the received array element radio frequency signals into four parallel signals with equal power, and to perform phase amplitude modulation processing on each parallel signal to generate four modulated parallel signals. The four modulated parallel signals are then transmitted to four combiners, where each combiner receives the modulated parallel signal of a sequence signal branch. Each combiner is used to combine and superimpose four modulated parallel signals from the same sequence number signal branch, so that the four modulated parallel signals from the same sequence number signal branch form corresponding independent first analog beam signals.

[0011] In one possible design, any multi-channel phase amplitude control network unit includes: a power divider, a multi-stage controllable phase shifting unit, and a multi-channel amplitude adjustment unit; The power divider is used to receive the array element radio frequency signal output by the corresponding array antenna element and distribute the received array element radio frequency signal into 4 parallel signals with equal power, wherein one parallel signal corresponds to one sequence signal branch. A multi-level controllable phase shifting unit is used to apply preset phase weights to the parallel signals of each sequence signal branch to obtain four parallel signals with phase adjustment. The multi-channel amplitude adjustment unit is used to perform weighted adjustment on the amplitude weights of the parallel signals after phase adjustment of each sequence signal branch, so as to obtain four-channel regulated parallel signals, and then transmit the four-channel regulated parallel signals to four combiners respectively.

[0012] In one possible design, the antenna subarray module includes: 16 beam subarray modules and four antenna subarray combiners, with each antenna subarray combiner corresponding to one sequence signal branch. The antenna subarray module is used to send the first analog beam signal of the i-th sequence signal branch output by the 16 beam subarray modules into the i-th antenna subarray combiner, so that the i-th antenna subarray combiner combines and superimposes the first analog beam signals of the four i-th sequence signal branches to generate the second analog beam signal corresponding to the i-th sequence signal branch, where i=1,2,3,4.

[0013] In one possible design, the four antenna subarray modules in the antenna module are respectively arranged in the four physical quadrant regions of the array surface, and one antenna subarray module corresponds to one physical quadrant region.

[0014] In one possible design, the downconversion processing module is used to downconvert the 16 actual analog beam signals generated by the antenna module to intermediate frequency signals or to baseband signals using the local oscillator signal, so that the 16 intermediate frequency signals or baseband signals are used as 16 processed signals.

[0015] In one possible design, the downconversion processing module includes: a local oscillator signal source, an RF front-end channel, and several frequency converters; Each actual analog beam signal corresponds to a radio frequency front-end channel, and each radio frequency front-end channel corresponds to a frequency converter. Each radio frequency front-end channel is used to transmit the received actual analog beam signal to its corresponding frequency converter. The local oscillator signal source is used to generate the local oscillator signal, and each radio frequency front-end channel is also used to synchronously send the local oscillator signal to its corresponding frequency converter. Each frequency converter is used to down-convert the received actual analog beam signal to an intermediate frequency signal or convert it into a baseband signal based on the local oscillator signal, so that the intermediate frequency signal or baseband signal can be used as the processed signal.

[0016] In one possible design, the multi-channel analog-to-digital converter module employs a 16-channel synchronous analog-to-digital converter, wherein each processed signal corresponds to one analog-to-digital conversion channel, and all analog-to-digital conversion channels share the same sampling clock source.

[0017] In one possible design, it also includes: a digital signal processing module, wherein the multi-channel analog-to-digital converter module is also used to transmit 16-channel digital signal sequences to the digital signal processing module; The digital signal processing module is used to extract the amplitude and phase of each digital signal sequence, so as to obtain the target azimuth angle based on the extracted amplitude and phase of each digital signal sequence.

[0018] Secondly, a subarray-based analog digital beamforming method is provided, wherein the method is implemented based on the subarray-based analog digital beamforming system of the first aspect or any possible design of the first aspect, and the method includes: Each beam subarray module acquires the radio frequency signals of four array elements, and combines and superimposes these signals to generate four independent first analog beam signals. According to the same-path superposition rule, the antenna subarray module performs a combination and superposition process on the first analog beam signals belonging to the same sequence number signal branch among the four first analog beam signals output by each beam subarray module to generate four independent second analog beam signals. The antenna module outputs four second analog beam signals generated by each of the four antenna subarray modules, to generate 16 independent actual analog beam signals that are transmitted to the downconversion processing module. The downconversion processing module processes the 16 actual analog beam signals generated by the antenna module to obtain 16 processed signals, where any one of the processed signals is a downconverted signal or a baseband signal. The multi-channel analog-to-digital converter module performs analog-to-digital conversion on 16 processed signals to output 16 digital signal sequences.

[0019] Thirdly, an apparatus for analog-digital beamforming based on subarrays is provided. Taking the apparatus as an electronic device as an example, it includes a memory, a processor, and a transceiver that are connected in sequence. The memory is used to store a computer program, the transceiver is used to send and receive messages, and the processor is used to read the computer program and execute the analog-digital beamforming method based on subarrays as described in the second aspect.

[0020] Fourthly, a storage medium is provided, on which instructions are stored, which, when executed on a computer, perform the subarray-based analog digital beamforming method as described in the second aspect.

[0021] Fifthly, a computer program product containing instructions is provided, which, when executed on a computer, cause the computer to perform the subarray-based analog digital beamforming method as described in the second aspect.

[0022] Beneficial effects: (1) This invention divides the antenna array into multiple subarrays (beam subarrays and antenna subarrays) through a hierarchical analog beamforming structure, and performs combining at each level to ultimately form multiple independent analog beams; finally, these analog beams can be converted from analog to digital (i.e., synchronous analog-to-digital sampling) in the digital domain to achieve analog-to-digital beamforming. Thus, the aforementioned hierarchical beamforming structure can achieve true parallel multi-beam output, and this structure can also enable the analog and digital parts to play their respective advantages, thereby enabling analog pre-synthesis and digital processing to work together, and thus achieving stable high-precision angle measurement in complex environments; based on this, this invention provides an analog-to-digital beamforming system that can achieve coordinated optimization of subarray-level parallel multi-beam analog synthesis and digital domain fine processing, which can meet the development needs of modern radar and communication systems, and is therefore very suitable for large-scale application and promotion. Attached Figure Description

[0023] Figure 1 A schematic diagram of the structure of a subarray-based analog digital beamforming system provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the beam subarray module provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the antenna subarray module provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the antenna module provided in an embodiment of the present invention; Figure 5 A flowchart illustrating the steps of the subarray-based analog digital beamforming method provided in this embodiment of the invention. Detailed Implementation

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the present invention will be briefly introduced below in conjunction with the accompanying drawings and descriptions of the embodiments or the prior art. Obviously, the following description of the structure of the accompanying drawings is only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. It should be noted that the description of these embodiments is for the purpose of helping to understand the present invention, but does not constitute a limitation of the present invention.

[0025] It should be understood that although the terms first, second, etc., may be used herein to describe various units, these units should not be limited by these terms. These terms are only used to distinguish one unit from another. For example, a first unit may be referred to as a second unit, and similarly, a second unit may be referred to as a first unit, without departing from the scope of the exemplary embodiments of the invention.

[0026] It should be understood that the term "and / or" that may appear in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, B exists alone, and A and B exist simultaneously. The term " / and" that may appear in this document describes another relationship between related objects, indicating that two relationships can exist. For example, A / and B can mean: A exists alone, and A and B exist alone. In addition, the character " / " that may appear in this document generally indicates that the related objects before and after it are in an "or" relationship.

[0027] Example: See Figures 1-4 As shown, the subarray-based analog-to-digital beamforming system provided in this embodiment designs a hierarchical combining structure to achieve coordinated optimization of parallel multi-beam analog beamforming and fine digital domain processing at the subarray level. For example, the system may include, but is not limited to, beam subarray modules, antenna subarray modules, antenna modules, down-conversion processing modules, and multi-channel analog-to-digital conversion modules. In specific implementation, each beam subarray module consists of 4 array antenna elements, each antenna subarray module consists of 16 beam subarray modules, and the entire antenna module consists of 4 antenna subarray modules, each corresponding to one of the four physical quadrants of the array surface. Thus, the overall antenna system comprises a total of 256 array antenna elements.

[0028] Optionally, the detailed structure and working process of each of the aforementioned modules are described below: In practical applications, the beam subarray module is used to acquire the radio frequency signals of four array elements and, based on these signals, combine and superimpose them to generate four independent first analog beam signals. In this embodiment, the beam subarray module is mainly used to combine and superimpose the signals of the signal branches within the same beam subarray unit to form four independent first analog beam signals. Its overall architecture is as follows: several array antenna elements are set in the beam subarray, and the rear end of each array antenna element is connected to multiple controllable phase and amplitude modulation networks. In this way, the input radio frequency signal can be distributed to multiple parallel branches, and preset phase weights and amplitude weights can be applied to each branch respectively. Finally, the signals of the same sequence number signal branch are combined and superimposed to simultaneously form multiple independent first analog beam signals in a single beam subarray.

[0029] Optionally, based on the aforementioned overall architecture, one specific structure of the beam subarray module is disclosed below: See Figure 2 As shown, any beam subarray module may include, but is not limited to, four array antenna elements, four multi-channel phase amplitude modulation network units, and four combiners; its specific working process is as follows: The output terminals of the four array antenna elements are each connected to a multi-channel phase amplitude modulation network unit, which is used to output the array element radio frequency signal to its corresponding multi-channel phase amplitude modulation network unit; in this way, the array element radio frequency signal can be acquired.

[0030] Then, each multi-channel phase-amplitude modulation network unit is used to distribute the received array element RF signals into four parallel signals with equal power, and to perform phase-amplitude modulation processing on each parallel signal to generate four modulated parallel signals. The four modulated parallel signals are then transmitted to four combiners (each combiner receives the modulated parallel signal of one sequence signal branch). Based on this, the array element RF signals received by each array antenna element can be distributed with equal power and modulated in phase and amplitude through their respective multi-channel phase-amplitude modulation network units.

[0031] For details, see Figure 2 As shown, in the aforementioned beam subarray module, the multi-channel phase-amplitude modulation network unit connected to the back end of any array antenna element may include, but is not limited to, a power divider, a multi-stage controllable phase-shifting unit, and a multi-channel amplitude adjustment unit. The power divider receives the array element RF signal output by the corresponding array antenna element and distributes the received array element RF signal into four parallel signals (one parallel signal corresponds to one sequence signal branch). Then, the multi-stage controllable phase-shifting unit applies a preset phase weight to the parallel signals of each sequence signal branch to obtain four phase-adjusted parallel signals. Finally, the multi-channel amplitude adjustment unit can be used to weight and adjust the amplitude weights of the phase-adjusted parallel signals of each sequence signal branch to obtain four modulated parallel signals, and transmits the four modulated parallel signals to four combiners (i.e., each sequence signal branch corresponds to one multi-stage controllable phase-shifting unit and one multi-channel amplitude adjustment unit, such as...). Figure 2 (as shown); in this way, the radio frequency signal of each array element can be divided into four, and the phase and amplitude of the four parallel signals can be controlled.

[0032] After phase and amplitude modulation is completed, combining processing can be performed. That is, each combiner is used to combine and superimpose the four modulated parallel signals of the same sequence number signal branch so that the four modulated parallel signals of the same sequence number signal branch form corresponding independent first analog beam signals.

[0033] In this embodiment, an example is used to illustrate the aforementioned combining process. See [link to example]. Figure 2 As shown, Figure 2 The image shows four power dividers, each outputting four parallel signals. After being processed by corresponding multi-stage controllable phase-shifting units and multi-channel amplitude adjustment units with preset phase and amplitude weights, they output four regulated parallel signals (corresponding to the regulated parallel signals of the first to fourth sequence signal branches, respectively). Figure 2 (Represented by 1-4 in the diagram) Thus, the modulated parallel signal corresponding to the first sequence signal branch output by the first multi-channel phase amplitude modulation network unit, the modulated parallel signal corresponding to the first sequence signal branch output by the second multi-channel phase amplitude modulation network unit, the modulated parallel signal corresponding to the first sequence signal branch output by the third multi-channel phase amplitude modulation network unit, and the modulated parallel signal corresponding to the first sequence signal branch output by the fourth multi-channel phase amplitude modulation network unit will all be sent to... Figure 2 The first combiner in the circuit can combine and superimpose the signals corresponding to the first sequence signal branch to generate a first analog beam signal; of course, the principle of combining and superimposing the signals of the other sequence signal branches is the same, which will not be elaborated here.

[0034] Therefore, the overall working process of the beam subarray module is as follows: In the beam subarray, each array element is first connected to a power divider to distribute the input radio frequency signal into four signals. Then, preset phase weights and amplitude weights are applied to each signal branch. Finally, the signals are combined and superimposed through a combiner to generate four independent analog beams (the combiner is configured to combine and superimpose signals from the same sequence number signal branch only, so that signal branches with different sequence numbers can form their own independent analog beams, thus generating four independent analog beams).

[0035] After completing one level of combining within the beam subarray module, a secondary combining of the simulated beams of the same sequence signal branch can be performed within the antenna subarray module. The process is as follows: See Figure 3 As shown, the antenna subarray module includes several beam subarray modules, which are used to perform combined superposition processing on the first analog beam signals belonging to the same sequence number signal branch among the four first analog beam signals output by each beam subarray module according to the same path superposition rule, so as to generate four independent second analog beam signals.

[0036] In this embodiment, the antenna subarray module specifically includes: 16 beam subarray modules and four antenna subarray combiners, and each antenna subarray combiner corresponds to one sequence signal branch; wherein, the antenna subarray module is used to send the first analog beam signal of the i-th sequence signal branch output by the 16 beam subarray modules to the i-th antenna subarray combiner, so that the i-th antenna subarray combiner combines and superimposes the first analog beam signals of the four i-th sequence signal branches received to generate the second analog beam signal corresponding to the i-th sequence signal branch, where i=1,2,3,4.

[0037] Specifically, the antenna subarray module consists of N (16) such... Figure 2 The beam subarray configuration shown is such that each beam subarray is operated in the aforementioned manner, thus generating four independent analog beams per subarray. Based on this, the N beam subarrays are then processed... Figure 2 The same operation shown (i.e., combining and superimposing signals from only the same sequence number signal branch) can eventually generate corresponding independent analog beams after passing through an N-to-1 combiner. Based on this, the antenna subarray can output four corresponding independent analog beams.

[0038] Therefore, the detailed working process of the antenna subarray module is as follows: First, the first analog beam signals output by the 16 beam subarray modules are simultaneously sent to the first antenna subarray combiner; then, the second analog beam signals of the 16 modules are sent to the second combiner; and so on. In this way, the 16-in-1 analog beams with the same sequence number can be combined and superimposed, and finally, 4 independent analog beam signals are output in each antenna subarray module.

[0039] After the antenna subarray module completes the combining and superposition of the analog beams with the same sequence number from the four first analog beam signals output by the 16 beam subarray modules, the antenna module can then be used to generate 16 actual analog beam signals. The process is as follows: See Figure 4 As shown, in this embodiment, the antenna module includes four antenna subarray modules, which are used to output four second analog beam signals generated by each of the four antenna subarray modules, so as to generate 16 independent actual analog beam signals to be transmitted to the downconversion processing module; that is, the antenna module is composed of four antenna subarray modules, and each antenna subarray can output four independent second analog beam signals. Therefore, the four antenna subarrays can form a total of 16 actual analog beam signal channels.

[0040] Furthermore, as exemplified, the four antenna subarray modules in the antenna module are respectively arranged in the four physical quadrant regions of the array surface (i.e., one antenna subarray module corresponds to one physical quadrant region). Figure 4In this diagram, A, B, C, and D each represent a physical quadrant region. This allows the overall antenna structure to output multiple analog beam signals in parallel, forming a quadrant-based, multi-beam spatial structure. In other words, each analog beam channel is independent of the others, thus covering different spatial directions or combinations of spatial weights.

[0041] After the antenna module outputs 16 independent actual analog beam signals, a down-conversion processing module can be used to process the signals, down-converting each actual analog beam signal to an intermediate frequency signal or converting it to a baseband signal. The process is as follows: The down-conversion processing module is used to process the 16 actual analog beam signals generated by the antenna module to obtain 16 processed signals (where any one of the processed signals is a down-converted signal or a baseband signal). Specifically, the down-conversion processing module is used to down-convert the 16 actual analog beam signals generated by the antenna module to an intermediate frequency signal or to convert them into a baseband signal using a local oscillator signal, so that the 16 intermediate frequency signals or baseband signals can be used as the 16 processed signals.

[0042] Optionally, the following discloses a detailed configuration of the downconversion processing module: In this embodiment, the frequency conversion processing module may include, but is not limited to, a local oscillator signal source, an RF front-end channel, and several frequency converters; wherein, each actual analog beam signal corresponds to an RF front-end channel, each RF front-end channel corresponds to a frequency converter, and each RF front-end channel is used to transmit the received actual analog beam signal to its corresponding frequency converter to realize the input of the actual analog beam.

[0043] Meanwhile, the local oscillator signal source is used to generate the local oscillator signal, and each RF front-end channel is also used to synchronously send the local oscillator signal into its corresponding frequency converter (synchronous sending can ensure reliable phase consistency between channels); finally, each frequency converter can be used to downconvert the received actual analog beam signal to an intermediate frequency signal or convert it into a baseband signal based on the local oscillator signal, so that the intermediate frequency signal or baseband signal can be used as the processed signal.

[0044] Therefore, after completing the down-conversion processing of each actual analog beam, analog-to-digital conversion and digital signal processing can be performed in the digital domain. The process is as follows: A multi-channel analog-to-digital converter (ADC) module is used to perform analog-to-digital conversion on 16 processed signals to output 16 digital signal sequences. In this embodiment, the multi-channel ADC module is a 16-channel synchronous analog-to-digital converter, where each processed signal corresponds to one ADC channel, and all ADC channels share the same sampling clock source (the sampling rate is set according to the system bandwidth). Thus, after the multi-channel ADC module synchronously samples and converts each down-converted signal into a digital signal, digital signal processing can be performed.

[0045] In this embodiment, the system also includes a digital signal processing module. The digital signal processing process is as follows: the multi-channel analog-to-digital conversion module is also used to transmit the 16-channel digital signal sequence to the digital signal processing module; the digital signal processing module is used to extract the amplitude and phase of each digital signal sequence, so as to obtain the target azimuth angle based on the amplitude and phase of each extracted digital signal sequence (i.e., to estimate the target signal direction angle based on the multi-channel signal); of course, the principle of multi-channel signal estimation of direction angle is a common technique in the field of analog synthetic multi-beam antennas, and will not be elaborated here.

[0046] Therefore, through the detailed description of the subarray-based analog digital beamforming system above, the present invention has the following beneficial effects: (1) Significantly reduce the number of digital channels: By performing multi-beam combining at the subarray level in the analog domain, only 16 analog beams need to be digitized (corresponding to 16 ADC channels), instead of the hundreds (e.g. 256) channels required by the traditional all-digital solution; thus, the system hardware size, power consumption, cost and data processing burden can be greatly reduced.

[0047] (2) Simplified RF link: Each array element only needs one set of RF front end, and multiple beams are realized through the multi-path analog network in the back end, avoiding the extreme complexity of configuring a complete RF link for each beam separately.

[0048] (3) Realize truly parallel multi-beam processing capability; among which, the subarray level generates multiple beams: in the basic beam subarray (composed of a few array elements), multiple (such as 4) independent analog beams can be generated simultaneously by multi-path phase amplitude modulation and same-index combination; at the same time, system-level parallel output is realized: this capability is recursively extended through hierarchical structure, ultimately enabling the entire antenna system to output 16 independent beams simultaneously and in real time, covering different spatial directions. In this way, multi-task parallel processing is realized, greatly improving the utilization rate of spatiotemporal resources.

[0049] (4) Improved spatial resolution and angle measurement accuracy; among them, the 16 pre-synthesized beams each represent a specific spatial weighting mode covering the entire array, which provides rich and structured spatial sampling information for digital domain processing; thus, in the digital domain, the coherent information (i.e. amplitude and phase) between the 16 signals can be used to perform high-resolution angle estimation, and its angle measurement accuracy and resolution are far higher than the natural width of the analog beams, approaching the performance of all-digital processing.

[0050] (5) The four antenna subarrays are arranged in quadrants, which naturally forms spatial diversity, which helps to suppress multipath fading and local interference. The hierarchical analog combining structure is regular and uniform, and the signal flow is clear. With the unified clock and local oscillator, it ensures good phase consistency and stability between system channels, which can lay the foundation for stable angle measurement in complex environments.

[0051] (6) By using a hierarchical analog beamforming structure, the array is divided into multiple subarrays (beam subarrays and antenna subarrays), and combined at each level to form multiple independent analog beams. Then, these analog beams are synchronously sampled and finely processed in the digital domain. In this way, the aforementioned hierarchical organization enables analog pre-synthesis and digital processing to work together. That is, the analog part provides wide coverage and multi-beam preliminary spatial sampling, and the digital part performs analog-to-digital conversion and target positioning on this basis. Based on this, the collaborative optimization between analog pre-synthesis and back-end digital processing can be realized, thereby achieving stable and high-precision angle measurement in complex environments.

[0052] like Figure 5 As shown, the second aspect of this embodiment provides a subarray-based analog digital beamforming method, wherein the method is implemented based on the subarray-based analog digital beamforming system described in the first aspect of the embodiment, and the operation steps of the method may be, but are not limited to, the steps S1 to S5 below.

[0053] S1. Each beam subarray module acquires the radio frequency signals of four array elements respectively, and combines and superimposes the radio frequency signals of the four array elements to generate four independent first analog beam signals; that is, in the beam subarray, the radio frequency signal corresponding to each array element is distributed to multiple parallel branches, and a preset phase value and amplitude value are applied to each branch. Then, the signals in the same order are combined and superimposed to form four independent first analog beams.

[0054] S2. The antenna subarray module performs a combination and superposition process on the first analog beam signals belonging to the same sequence number signal branch among the four first analog beam signals output by each beam subarray module according to the same path superposition rule, so as to generate four independent second analog beam signals; specifically, the antenna subarray is composed of N beam subarrays, and the operation shown in S1 is performed on the beam subarrays to generate four independent second analog beams.

[0055] S3. The antenna module outputs four second analog beam signals generated by each of the four antenna subarray modules, to generate 16 independent actual analog beam signals that are transmitted to the downconversion processing module.

[0056] S4. The downconversion processing module processes the 16 actual analog beam signals generated by the antenna module to obtain 16 processed signals, where any one of the processed signals is a downconverted signal or a baseband signal.

[0057] S5. The multi-channel analog-to-digital converter module performs analog-to-digital conversion on 16 channels of processed signals to output 16 channels of digital signal sequences.

[0058] The working process, working details and technical effects of the method provided in this embodiment can be found in the first aspect of the embodiment, and will not be repeated here.

[0059] The third aspect of this embodiment provides an analog-digital beamforming apparatus based on a subarray. Taking an electronic device as an example, it includes a memory, a processor, and a transceiver that are sequentially and communicatively connected. The memory is used to store a computer program, the transceiver is used to send and receive messages, and the processor is used to read the computer program and execute the analog-digital beamforming method based on a subarray as described in the second aspect of this embodiment.

[0060] For specific examples, the memory may include, but is not limited to, random access memory (RAM), read-only memory (ROM), flash memory, first-in-first-out (FIFO) memory, and / or first-in-last-out (FILO) memory, etc.; specifically, the processor may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor may be implemented using at least one hardware form of DSP (Digital Signal Processing), FPGA (Field-Programmable Gate Array), PLA (Programmable Logic Array). The processor may also include a main processor and a coprocessor. The main processor, also known as the CPU (Central Processing Unit), is used to process data in the wake-up state; the coprocessor is a low-power processor used to process data in the standby state.

[0061] In some embodiments, the processor may integrate a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content to be displayed on the screen. For example, the processor may not be limited to microprocessors of the STM32F105 series, reduced instruction set computer (RISC) microprocessors, x86 architecture processors, or processors with integrated neural network processing units (NPUs). The transceiver may be, but is not limited to, a Wi-Fi transceiver, a Bluetooth transceiver, a General Packet Radio Service (GPRS) transceiver, a ZigBee (a low-power LAN protocol based on the IEEE 802.15.4 standard) transceiver, a 3G transceiver, a 4G transceiver, and / or a 5G transceiver. Furthermore, the device may also include, but is not limited to, a power module, a display screen, and other necessary components.

[0062] The working process, working details and technical effects of the electronic device provided in this embodiment can be found in the first aspect of the embodiment, and will not be repeated here.

[0063] The fourth aspect of this embodiment provides a storage medium for storing instructions containing the subarray-based analog digital beamforming method described in the second aspect of the embodiment. That is, the storage medium stores instructions that, when executed on a computer, perform the subarray-based analog digital beamforming method as described in the second aspect of the embodiment.

[0064] The storage medium refers to a carrier for storing data, which may include, but is not limited to, floppy disks, optical disks, hard disks, flash memory, USB flash drives, and / or memory sticks. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices.

[0065] The working process, working details and technical effects of the storage medium provided in this embodiment can be found in the first aspect of the embodiment, and will not be repeated here.

[0066] The fifth aspect of this embodiment provides a computer program product containing instructions that, when executed on a computer, cause the computer to perform the subarray-based analog digital beamforming method as described in the second aspect of this embodiment, wherein the computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device.

[0067] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A subarray-based analog-digital beamforming system, characterized in that, include: The beam subarray module is used to acquire the radio frequency signals of four array elements and, based on the radio frequency signals of the four array elements, combine and superimpose them to generate four independent first analog beam signals. The antenna subarray module includes several beam subarray modules, which are used to perform combining and superimposing processing on the first analog beam signals belonging to the same sequence number signal branch among the four first analog beam signals output by each beam subarray module according to the same path superposition rule, so as to generate four independent second analog beam signals. The antenna module includes four antenna subarray modules, which are used to output four second analog beam signals generated by each of the four antenna subarray modules to generate 16 independent actual analog beam signals to be transmitted to the downconversion processing module. The downconversion processing module is used to process the 16 actual analog beam signals generated by the antenna module to obtain 16 processed signals, wherein any processed signal is a downconverted signal or a baseband signal. The multi-channel analog-to-digital converter module is used to perform analog-to-digital conversion on 16 channels of processed signals to output 16 channels of digital signal sequences.

2. The analog-digital beamforming system based on a subarray according to claim 1, characterized in that, The beam subarray module includes: four array antenna elements, four multi-channel phase amplitude modulation network units, and four combiners; The output terminals of the four array antenna elements are each connected to a multi-channel phase amplitude modulation network unit, which is used to output the array element radio frequency signal to their respective multi-channel phase amplitude modulation network unit; Each multi-channel phase amplitude modulation network unit is used to divide the received array element radio frequency signals into four parallel signals with equal power, and to perform phase amplitude modulation processing on each parallel signal to generate four modulated parallel signals. The four modulated parallel signals are then transmitted to four combiners, where each combiner receives the modulated parallel signal of a sequence signal branch. Each combiner is used to combine and superimpose four modulated parallel signals from the same sequence number signal branch, so that the four modulated parallel signals from the same sequence number signal branch form corresponding independent first analog beam signals.

3. The analog-digital beamforming system based on a subarray according to claim 2, characterized in that, Any multi-channel phase-amplitude control network unit includes: a power divider, a multi-stage controllable phase-shifting unit, and a multi-channel amplitude adjustment unit; The power divider is used to receive the array element radio frequency signal output by the corresponding array antenna element and distribute the received array element radio frequency signal into 4 parallel signals with equal power, wherein one parallel signal corresponds to one sequence signal branch. A multi-level controllable phase shifting unit is used to apply preset phase weights to the parallel signals of each sequence signal branch to obtain four parallel signals with phase adjustment. The multi-channel amplitude adjustment unit is used to perform weighted adjustment on the amplitude weights of the parallel signals after phase adjustment of each sequence signal branch, so as to obtain four-channel regulated parallel signals, and then transmit the four-channel regulated parallel signals to four combiners respectively.

4. The analog-digital beamforming system based on a subarray according to claim 1, characterized in that, The antenna subarray module includes: 16 beam subarray modules and four antenna subarray combiners, with each antenna subarray combiner corresponding to one sequence signal branch. The antenna subarray module is used to send the first analog beam signal of the i-th sequence signal branch output by the 16 beam subarray modules into the i-th antenna subarray combiner, so that the i-th antenna subarray combiner combines and superimposes the first analog beam signals of the four i-th sequence signal branches to generate the second analog beam signal corresponding to the i-th sequence signal branch, where i=1,2,3,4.

5. The analog-digital beamforming system based on a subarray according to claim 1, characterized in that, The four antenna subarray modules in the antenna module are respectively arranged in the four physical quadrant regions of the array surface, and one antenna subarray module corresponds to one physical quadrant region.

6. The analog-digital beamforming system based on a subarray according to claim 1, characterized in that, The downconversion processing module is used to downconvert the 16 actual analog beam signals generated by the antenna module to intermediate frequency signals or to baseband signals using the local oscillator signal, so that the 16 intermediate frequency signals or baseband signals can be used as 16 processed signals.

7. The analog-digital beamforming system based on a subarray according to claim 6, characterized in that, The downconversion processing module includes: a local oscillator signal source, an RF front-end channel, and several frequency converters; Each actual analog beam signal corresponds to a radio frequency front-end channel, and each radio frequency front-end channel corresponds to a frequency converter. Each radio frequency front-end channel is used to transmit the received actual analog beam signal to its corresponding frequency converter. The local oscillator signal source is used to generate the local oscillator signal, and each radio frequency front-end channel is also used to synchronously send the local oscillator signal to its corresponding frequency converter. Each frequency converter is used to down-convert the received actual analog beam signal to an intermediate frequency signal or convert it into a baseband signal based on the local oscillator signal, so that the intermediate frequency signal or baseband signal can be used as the processed signal.

8. The analog-digital beamforming system based on a subarray according to claim 1, characterized in that, The multi-channel analog-to-digital converter module uses a 16-channel synchronous analog-to-digital converter, where each processed signal corresponds to an analog-to-digital converter channel, and all analog-to-digital converter channels share the same sampling clock source.

9. The analog-digital beamforming system based on a subarray according to claim 1, characterized in that, Also includes: The digital signal processing module, including the multi-channel analog-to-digital converter module, is also used to transmit 16-channel digital signal sequences to the digital signal processing module; The digital signal processing module is used to extract the amplitude and phase of each digital signal sequence, so as to obtain the target azimuth angle based on the extracted amplitude and phase of each digital signal sequence.

10. A subarray-based analog-digital beamforming method, characterized in that, The method is implemented based on the subarray-based analog digital beamforming system according to any one of claims 1 to 9, wherein the method includes: Each beam subarray module acquires the radio frequency signals of four array elements, and combines and superimposes these signals to generate four independent first analog beam signals. According to the same-path superposition rule, the antenna subarray module performs a combination and superposition process on the first analog beam signals belonging to the same sequence number signal branch among the four first analog beam signals output by each beam subarray module to generate four independent second analog beam signals. The antenna module outputs four second analog beam signals generated by each of the four antenna subarray modules, to generate 16 independent actual analog beam signals that are transmitted to the downconversion processing module. The downconversion processing module processes the 16 actual analog beam signals generated by the antenna module to obtain 16 processed signals, where any one of the processed signals is a downconverted signal or a baseband signal. The multi-channel analog-to-digital converter module performs analog-to-digital conversion on 16 processed signals to output 16 digital signal sequences.

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