Method for realizing signal capture and adaptive tracking based on phased array

Abstract

The invention discloses a method for realizing signal acquisition and self-adaptive tracking based on a phased array, which is particularly suitable for a communication system, realizes accurate acquisition and real-time tracking of signals through wide and narrow beam conversion, and mainly comprises three parts of wide beam scanning, wide and narrow beam accurate acquisition and self-adaptive tracking. The phased-array antenna firstly performs preliminary signal scanning in a wide-beam mode to quickly cover a large-range area so as to capture potential target signals, and once the target signals are captured, the phased-array antenna is switched to a narrow-beam mode so as to improve the signal capture precision and the signal-to-noise ratio. Meanwhile, in the capturing process, the beam direction and shape of the phased-array antenna are adjusted in real time, target signals are continuously tracked, and the capturing effect is optimized. According to the invention, the practical problems of low signal acquisition precision, poor tracking real-time performance, easy interruption of a communication link and the like in a complex communication scene are solved.

Description

Technical Field

[0001] This invention relates to the field of phased array technology, and in particular to a method for signal acquisition and adaptive tracking based on a phased array. Background Technology

[0002] Phased array technology has been increasingly widely used in communication technology in recent years. It features high scanning accuracy, fast response speed, and multi-beam operation, making it suitable for most current communication scenarios. With the increasing maturity of phased array technology, beam switching technology has become a hot topic, especially given the scarcity of time and frequency resources. Currently, domestic analyses of foreign Starlink systems suggest that they likely employ beam-hopping technology to achieve high data rates.

[0003] In current application scenarios, while efficiently utilizing spectrum resources, complex beam switching operation modes have also emerged. Beam switching is fundamental to ensuring continuous communication services in mobile communication systems under complex conditions. However, due to the high-speed movement of both communicating parties, how to switch and maintain switching stability are pressing research directions. Furthermore, the success of the switch directly impacts the performance indicators of the entire communication system. Therefore, ensuring reliable communication under beam switching mode is an urgent research problem.

[0004] In complex communication scenarios, research on beam switching schemes is of paramount importance. For example, in high-speed mobile scenarios, frequent beam switching can easily cause communication link failures. In millimeter-wave communication scenarios (sub-6GHz), actual communication is highly susceptible to path loss, which is several orders of magnitude higher than that of low-frequency bands. Therefore, millimeter-wave communication requires the use of phased arrays and further beamforming techniques to improve spectral efficiency and offset the losses caused by high path loss.

[0005] The statements herein provide only background information in relation to this invention and do not necessarily constitute prior art. Summary of the Invention

[0006] The purpose of this invention is to provide a method for signal acquisition and adaptive tracking based on phased array, in order to solve practical problems such as low signal acquisition accuracy, poor real-time tracking, and easy interruption of communication links in complex communication scenarios (such as high-speed mobile scenarios and scenarios with scarce spectrum resources), thereby achieving continuous tracking of target signals and optimizing acquisition effects, and ensuring reliable communication in beam switching mode.

[0007] To achieve the above objectives, the present invention provides a method for signal acquisition and adaptive tracking based on a phased array, comprising: S1. Based on the application scenario, coverage requirements, signal characteristic parameters and environmental constraints of the communication system, the fixed direction of the phased array antenna is calculated through simulation. The fixed direction is a wide beam direction. S2. Centered on the wide beam pointing direction determined in step S1, the target signal within the specified frequency band range that meets the preset requirements of the communication system is scanned by combining the half-power beamwidth and scanning strategy in the wide beam mode of the phased array antenna; after the target signal is captured and decoded, the phased array antenna beam mode is switched from wide beam mode to narrow beam mode, and the phased array antenna is oriented to the position of the scanned target signal; S3. At the beginning of each time slot period, extract the transmitter's position information from the target signal captured in step S2, combine it with the receiver's real-time position information, calculate the relative off-axis angle and rotation angle to characterize the relative spatial orientation relationship between the transmitter and the receiver, and adjust the phase difference of the phased array antenna elements according to the calculated off-axis angle and rotation angle to change the beam pointing angle of the phased array antenna so that the narrow beam is directed to the spatial position of the transmitter. S4. During the target signal search process, each time the receiver captures a target signal, it recalculates the relative spatial orientation relationship between the receiver and the transmitter based on the transmitter's position information extracted from the target signal, and adjusts the beam pointing angle of the phased array antenna in real time according to the calculation results. If the target signal is not found within a preset time, the fixed pointing is switched back to wide beam pointing. After the target signal is received, steps S2 to S4 are repeated.

[0008] In one embodiment, the scanning strategy described in step S2 includes: step scanning in the horizontal direction, with each step scanning angle being 15°, and the scanning range covered in the horizontal direction being -90° to +90°; and fixed coverage of ±15° in the vertical direction.

[0009] In one embodiment, the conditions for the target signal that meets the preset requirements of the communication system in step S2 include at least: condition 1, the frame header of the target signal matches the frame header in the preset requirements; condition 2, the strength of the target signal matches the signal strength in the preset requirements.

[0010] In one embodiment, the preset time mentioned in step S4 is no more than 10 transmission cycles.

[0011] In one embodiment, in step S2, when the phased array antenna beam mode switches from wide beam mode to narrow beam mode, the half-power beamwidth of the narrow beam mode is the minimum feasible value to maximize beam gain.

[0012] In one embodiment, when the phased array antenna beam pattern is a wide beam pattern, step S2 further includes a step of finding a balance between the required scanning range and the gain, specifically: calculating the initial beam parameters based on the array factor formula of the phased array antenna, optimizing the beam parameters in conjunction with the scanning strategy, and verifying the optimized beam parameters through a phased array simulation tool; the array factor formula of the phased array antenna is as follows:

[0013] in, For the first The amplitude weighting coefficients of each array element, For wave number, For the first The distance between each array element and the reference array element This refers to the beam pointing angle.

[0014] In one embodiment, obtaining the position of the target signal described in step S2 includes the following steps: S21. The phased array antenna receives the modulation signal emitted by the transmitter; the modulation signal is as follows:

[0015] in, The spectral function representing a Gaussian filter, , For carrier components, , Represent , Two signals; S22. After the modulated signal undergoes quadrature downconversion... The road is:

[0016] The road is:

[0017] S22, the result obtained after the orthogonal downconversion , The two signals are respectively subjected to data matching filtering and then transmitted to the demodulation module for demodulation. After demodulation, the original data information transmitted by the transmitter is obtained, and the position of the target is obtained according to the specified protocol.

[0018] In one embodiment, the method for signal acquisition and adaptive tracking based on a phased array further includes: adjusting the phase difference of the phased array antenna elements according to the radiation pattern function of the phased array antenna; wherein, the radiation pattern function of the phased array antenna is as follows:

[0019] in, The amplitude weighting coefficients for the (m, n)th antenna element are... Let be the spatial phase difference between the (m, n)th antenna element and the (0, 0)th antenna element. Let be the beam phase control difference of the (m, n)th antenna element.

[0020] Compared with existing technologies, the method for signal acquisition and adaptive tracking based on phased array proposed in this invention has at least the following beneficial effects: Through a three-level collaborative mechanism of "wide beam wide-range scanning, narrow beam precise acquisition, and adaptive dynamic tracking", combined with precise calculation of array element phase difference and beam pattern optimization, it can achieve rapid acquisition and stable tracking of target signals. It is especially suitable for communication systems that require efficient use of spectrum resources and high requirements for communication continuity (such as satellite communication, terrestrial mobile base station communication, etc.), which can effectively improve signal acquisition efficiency and tracking accuracy, and ensure the reliability of communication links in complex dynamic scenarios. Attached Figure Description

[0021] Figure 1 This is a flowchart of the method for signal acquisition and adaptive tracking based on a phased array according to the present invention. Detailed Implementation

[0022] The method for signal acquisition and adaptive tracking based on a phased array, as proposed in this invention, will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of this invention will become clearer from the following description. It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions, used only to facilitate and clearly illustrate the embodiments of this invention. Please refer to the accompanying drawings to make the objectives, features, and advantages of this invention more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for illustrative purposes to aid those skilled in the art and are not intended to limit the implementation conditions of this invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to the size, without affecting the effects and objectives achieved by this invention, should still fall within the scope of the technical content disclosed in this invention.

[0023] The embodiments of the present invention provide a method for signal acquisition and adaptive tracking based on a phased array. It achieves rapid acquisition and stable tracking of target signals through a three-level collaborative mechanism of wide-beam wide-range scanning, narrow-beam precise acquisition, and adaptive dynamic tracking, combined with precise calculation of array element phase difference and beam pattern optimization.

[0024] like Figure 1As shown, the method for signal acquisition and adaptive tracking based on a phased array, with "wide-beam fast scanning - narrow-beam precise acquisition - adaptive dynamic tracking" as its core logic, specifically includes the following steps: S1. Based on the application scenario, coverage requirements, signal characteristic parameters and environmental constraints of the communication system, the fixed direction of the phased array antenna is calculated through simulation. The fixed direction is a wide beam direction.

[0025] S2. Wide-beam scanning and switching: Centered on the wide-beam pointing direction determined in step S1, the target signal within the specified frequency band range that meets the preset requirements of the communication system is scanned by combining the half-power beamwidth (HPBW) in the wide-beam mode of the phased array antenna and the scanning strategy; after the target signal is captured and decoded, the phased array antenna beam mode is switched from wide-beam mode to narrow-beam mode, and the phased array antenna is oriented to the position of the scanned target signal to increase the performance of the phased array receiving signal, and the received signal is down-converted, filtered, and demodulated to obtain position information.

[0026] The scanning strategy described in step S2 includes: step scanning in the horizontal direction, with each step scanning angle being 15°, and the horizontal scanning range being -90° to +90°; and fixed coverage of ±15° in the vertical direction to meet the scanning coverage range.

[0027] Furthermore, the conditions for the target signal that meet the preset requirements of the communication system mentioned in step S2 include at least the following: Condition 1, the frame header of the target signal matches the frame header in the preset requirements; Condition 2, the strength of the target signal matches the signal strength in the preset requirements, so as to effectively improve the signal acquisition efficiency and tracking accuracy and ensure the reliability of the communication link in complex dynamic scenarios.

[0028] When the phased array antenna beam pattern switches from wide beam pattern to narrow beam pattern, in order to ensure sufficient gain during normal communication, the narrow beam needs to be as narrow as possible. That is, under the constraints of phased array antenna hardware performance and system communication requirements, the beamforming parameters (such as array element amplitude weighting, phase difference control, etc.) are adjusted to make the half-power beamwidth of the narrow beam pattern the minimum feasible value, so as to maximize beam gain, reduce the reception of signals in non-target directions, and improve the signal-to-noise ratio during directional tracking.

[0029] Meanwhile, in wide-beam mode, it is required to ensure a sufficiently large coverage area without too much gain. Therefore, in narrow-beam mode, when gain needs to be guaranteed, when the phased array antenna beam pattern is wide-beam mode, step S2 also includes a step of finding a balance between the required coverage scanning range and gain. Specifically, the initial beam parameters are calculated based on the array factor formula of the phased array antenna, and the beam parameters are optimized in combination with the scanning strategy (i.e., step scanning in the horizontal direction and fixed coverage in the vertical direction). The optimized beam parameters are then simulated and verified using a phased array simulation tool (HFSS). The simulation model must first be built according to the two-dimensional phased array hardware structure (number of array elements M×N, array element spacing d1 / d2), wide-beam optimization parameters (amplitude weighting coefficient wᵢ, initial phase offset φ), and complex communication scenarios (such as sub6G millimeter wave path loss and noise threshold) in the file. Then, far-field radiation analysis is run to output the beam pattern and gain distribution, verifying the horizontal -90°~+90° and vertical ±15°. Check if the scanning range has no blind spots (half-power point coverage), whether the gain of the covered area is greater than or equal to the minimum effective acquisition gain and the fluctuation is ≤3dB, and confirm that the sidelobe is ≤-20dB and HPBW is matched in 15° steps. Finally, analyze the results. If the scanning range meets the requirements but the gain is insufficient, use Chebyshev weighting or other methods to increase the gain. If the gain meets the requirements but the range is insufficient, relax the sidelobe suppression or other methods to widen the beam. Iterate and optimize until the parameters meet the file's wide beam "fast coverage + effective acquisition" requirements, that is, determine the balance between the two.

[0030] The array factor formula for the phased array antenna is as follows:

[0031] in, For the first The amplitude weighting coefficients of each array element, For wave number, For the first The distance between each array element and the reference array element This refers to the beam pointing angle.

[0032] In one embodiment, obtaining the position of the target signal mentioned in step S2 includes the following steps: S21. The phased array antenna receives the modulation signal emitted by the transmitter; the modulation signal is as follows:

[0033] in, The spectral function representing a Gaussian filter, , For carrier components, , Represent , Two signals; S22. After the modulated signal undergoes quadrature downconversion... The road is:

[0034] The road is:

[0035] S22, the result obtained after the orthogonal downconversion , The two signals are respectively subjected to data matching filtering and then transmitted to the demodulation module for demodulation. After demodulation, the original data information transmitted by the transmitter is obtained, and the position of the target is obtained according to the specified protocol.

[0036] S3. Narrow beam pointing adjustment: At the beginning of each time slot period, the transmitter's position information is extracted from the target signal captured in step S2. Combined with the receiver's real-time position information, the relative off-axis angle and rotation angle, which characterize the relative spatial orientation relationship between the transmitter and the receiver, are calculated. The phase difference of the phased array antenna elements is adjusted according to the calculated off-axis angle and rotation angle to change the beam pointing angle of the phased array antenna, so that the narrow beam is directed to the spatial position of the transmitter, that is, the narrow beam is precisely pointed to the transmitter.

[0037] S4. Tracking and Cyclic Switching: During the target signal search process, each time the receiver acquires a target signal, it recalculates the relative spatial orientation between the receiver and the transmitter based on the transmitter's position information extracted from the target signal, and adjusts the beam pointing angle of the phased array antenna in real time according to the calculation result. If no target signal is found within a preset time, the fixed pointing is switched back to wide beam pointing. After the target signal is received, steps S2 to S4 are repeated. As an optional embodiment, the preset time is no more than 10 transmission cycles.

[0038] In one embodiment, the total number of array elements in the two-dimensional phased array is M×N, the distance between array elements along the X-axis is d1, the distance between array elements along the Y-axis is d2, and the phase difference between two adjacent array elements can be expressed as follows:

[0039]

[0040] in, Where d is the signal wavelength, and d1 and d2 represent the spacing between adjacent array elements in the X-axis and Y-axis directions, respectively. , These represent the angles between the incident signal directions along the X and Y axes and the normal to the array surface, respectively.

[0041] By using the (0,0)th antenna element as a reference, the spatial phase difference between the (m,n)th antenna element and it is calculated:

[0042] use and Represent the phase difference of the antenna elements on the X and Y axes, respectively:

[0043]

[0044] The intra-array phase difference between the (m, n)th antenna element and the (0, 0)th antenna element is:

[0045] When using spherical coordinates, the angle between the phased array antenna pointing and the Y-axis is expressed as:

[0046] The angle between the target and the Y-axis can be obtained as follows:

[0047] then:

[0048]

[0049] Assume the amplitude weighting coefficient of the (m, n)th antenna element is Ignoring the influence of the antenna element radiation pattern, the radiation pattern function of the phased array antenna is expressed as:

[0050] in, The amplitude weighting coefficients for the (m, n)th antenna element are... Let be the spatial phase difference between the (m, n)th antenna element and the (0, 0)th antenna element. Let be the beam phase control difference of the (m, n)th antenna element. The expression for the radiation pattern function of this phased array antenna shows the spatial distribution of the quantized beam. Based on this expression, the element parameters (e.g., the phase difference of the phased array antenna elements) are adjusted to improve signal quality.

[0051] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0052] In the description of this invention, it should be understood that the terms "center," "height," "thickness," "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0053] In the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0054] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0055] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A method for signal acquisition and adaptive tracking based on a phased array, characterized in that, include: S1. Based on the application scenario, coverage requirements, signal characteristic parameters and environmental constraints of the communication system, the fixed direction of the phased array antenna is calculated through simulation. The fixed direction is a wide beam direction. S2. Centered on the wide beam pointing direction determined in step S1, the target signal within the specified frequency band range that meets the preset requirements of the communication system is scanned by combining the half-power beamwidth and scanning strategy in the wide beam mode of the phased array antenna; after the target signal is captured and decoded, the phased array antenna beam mode is switched from wide beam mode to narrow beam mode, and the phased array antenna is oriented to the position of the scanned target signal; S3. At the beginning of each time slot period, extract the transmitter's position information from the target signal captured in step S2, combine it with the receiver's real-time position information, calculate the relative off-axis angle and rotation angle to characterize the relative spatial orientation relationship between the transmitter and the receiver, and adjust the phase difference of the phased array antenna elements according to the calculated off-axis angle and rotation angle to change the beam pointing angle of the phased array antenna so that the narrow beam is directed to the spatial position of the transmitter. S4. During the target signal search process, each time the receiver captures a target signal, it recalculates the relative spatial orientation relationship between the receiver and the transmitter based on the transmitter's position information extracted from the target signal, and adjusts the beam pointing angle of the phased array antenna in real time based on the calculation results. If the target signal is not found within the preset time, switch the fixed pointing to wide beam pointing again. After the target signal is received, repeat steps S2 to S4.

2. The method as described in claim 1, characterized in that, The scanning strategy described in step S2 includes: step scanning in the horizontal direction, with each step scanning angle being 15°, and the horizontal scanning range being -90° to +90°; and fixed coverage of ±15° in the vertical direction.

3. The method as described in claim 1, characterized in that, The conditions for the target signal that meet the preset requirements of the communication system mentioned in step S2 include at least the following: Condition 1, the frame header of the target signal matches the frame header in the preset requirements; Condition 2, the strength of the target signal matches the signal strength in the preset requirements.

4. The method as described in claim 1, characterized in that, The preset time mentioned in step S4 is no more than 10 transmission cycles.

5. The method as described in claim 1, characterized in that, In step S2, when the phased array antenna beam mode switches from wide beam mode to narrow beam mode, the half-power beamwidth of the narrow beam mode is the minimum feasible value in order to maximize beam gain.

6. The method as described in claim 2, characterized in that, When the phased array antenna beam pattern is wide beam pattern, step S2 also includes a step of finding a balance between the required scanning range and the gain, specifically: The initial beam parameters are calculated based on the array factor formula of the phased array antenna, and the beam parameters are optimized in conjunction with the scanning strategy. The optimized beam parameters are then verified through phased array simulation tools. The array factor formula of the phased array antenna is as follows: in, For the first The amplitude weighting coefficients of each array element, For wave number, For the first The distance between each array element and the reference array element This refers to the beam pointing angle.

7. The method as described in claim 1, characterized in that, Obtaining the position of the target signal mentioned in step S2 includes the following steps: S21. The phased array antenna receives the modulation signal emitted by the transmitter; the modulation signal is as follows: in, The spectral function representing a Gaussian filter, , For carrier components, , Represent , Two signals; S22. After the modulated signal undergoes quadrature downconversion... The road is: The road is: S22, the result obtained after the orthogonal downconversion , The two signals are respectively subjected to data matching filtering and then transmitted to the demodulation module for demodulation. After demodulation, the original data information transmitted by the transmitter is obtained, and the position of the target is obtained according to the specified protocol.

8. The method as described in claim 1, characterized in that, Also includes: The phase difference between the phased array antenna elements is adjusted according to the radiation pattern function of the phased array antenna; wherein, the radiation pattern function of the phased array antenna is as follows: in, The amplitude weighting coefficients for the (m, n)th antenna element are... Let be the spatial phase difference between the (m, n)th antenna element and the (0, 0)th antenna element. Let be the beam phase control difference of the (m, n)th antenna element.

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