Antenna control method and antenna system

Abstract

This invention discloses an antenna control method and antenna system. The antenna control method includes the following steps: loading initial transmit / receive direction data; receiving signals from multiple satellites based on the initial transmit / receive direction data to obtain multiple signal strength data; establishing a candidate list from the multiple signal strength data using a minimum strength threshold; selecting the satellite with the maximum signal strength data from the candidate list as the target object; when the signal strength data of the target object is greater than a predetermined strength threshold, obtaining the baseband signal data of the target object and inputting the baseband signal data into a subspace tracking method to obtain principal eigenvector data and principal eigenvalue data; inputting the principal eigenvector data and principal eigenvalue data into ESPRIT to obtain the direction of arrival data of the target object; and adjusting the beam according to the direction of arrival data to track the target object.

Description

Technical Field

[0001] This invention relates to a control method, and more particularly to an antenna control method and antenna system. Prior Technology

[0002] Mobile vehicles often need to communicate with satellites during their movement (e.g., satellite positioning, satellite networks), so they are equipped with antenna systems capable of tracking satellite signals. However, the computational efficiency of existing antenna systems in calculating satellite positions is not ideal, especially for maritime mobile vehicles that experience both horizontal and vertical changes, which can lead to the beam of existing antenna systems being unable to be aligned with the satellite, resulting in poor transmission efficiency.

[0003] Therefore, the inventor believed that the above-mentioned defects could be improved. So he devoted himself to research and applied scientific principles, and finally proposed an invention that is reasonably designed and effectively improves the above-mentioned defects. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an antenna control method and antenna system that address the shortcomings of the prior art.

[0005] One embodiment of the present invention discloses an antenna control method applied to an antenna system. The control method includes the following steps: loading initial transmit / receive direction data; using an array antenna to receive signals from multiple satellites according to the initial transmit / receive direction data to obtain multiple signal strength data; establishing a candidate list from the multiple signal strength data using a minimum strength threshold; selecting the satellite with the largest signal strength data from the candidate list as a target object; when the signal strength data of the target object is less than a predetermined strength threshold, switching other satellites from the candidate list to the target object; when the signal strength data of the target object is greater than the predetermined strength threshold, using the array antenna to obtain a baseband signal data of the target object, and inputting the baseband signal data into a subspace tracking method to obtain a principal feature vector data and a principal feature value data; inputting the principal feature vector data and the principal feature value data into a rotation-invariant technique (ESPRIT) estimation method to obtain a direction of arrival data of the target object. Arrival (DOA); and adjust the beam according to the arrival direction data to track the target object.

[0006] One embodiment of the present invention discloses an antenna control method applied to an antenna system. The control method includes the following steps: loading initial transmit / receive direction data; using an array antenna to receive signals from multiple satellites according to the initial transmit / receive direction data to obtain multiple signal strength data; establishing a candidate list from the multiple signal strength data using a minimum strength threshold; selecting the satellite with the largest signal strength data from the candidate list as a target object; when the signal strength data of the target object is less than a predetermined strength threshold, switching other satellites from the candidate list to serve as the target object; when the signal strength data of the target object is greater than the predetermined strength threshold, distinguishing multiple working subarrays using multiple antennas of the array antenna, and obtaining multiple baseband signal data of the target object using the multiple working subarrays respectively; inputting each baseband signal data into a subspace tracking method to obtain a principal feature vector data and a principal feature value data; inputting the principal feature vector data and the principal feature value data into a rotation-invariant parameter estimation method (Estimation of Signal Parameters via Rotational Invariance). In the Techniques (ESPRIT), a direction of arrival (DOA) data of the target object is obtained; the beam is adjusted and the target object is tracked based on multiple DOA data.

[0007] One embodiment of the present invention discloses an antenna system, comprising: an array antenna capable of receiving signals from multiple satellites to obtain multiple signal strength data; a dynamic adjustment module connected to the array antenna, the dynamic adjustment module controlling the array antenna to face one of the satellites based on initial transmit / receive direction data and a direction of arrival (DOA) data; and a tracking module connected to the array antenna and the dynamic adjustment module, wherein when the dynamic adjustment module loads the initial transmit / receive direction data, the tracking module can establish a candidate list from the multiple signal strength data using a minimum strength threshold, and select the satellite with the highest signal strength data from the candidate list as a target object; wherein, when the tracking module detects that the signal strength data of the target object is less than a predetermined strength threshold, the tracking module switches to other satellites from the candidate list as the target. When the tracking module detects that the signal strength data of the target object is greater than the predetermined strength threshold, the tracking module issues a calculation command. A calculation module is connected to the array antenna, the tracking module, and the dynamic adjustment module. When the calculation module receives the calculation command, it uses the array antenna to obtain a baseband signal data of the target object and inputs the baseband signal data into a subspace tracking method to obtain a principal feature vector data and a principal feature value data. The calculation module uses the principal feature vector data and the principal feature value data into a rotation-invariant technique (ESPRIT) to obtain the direction of arrival data of the target object. The calculation module uses the direction of arrival data to replace the initial transmit / receive direction data, so that the dynamic adjustment module controls the array antenna to face the target object according to the direction of arrival data.

[0008] One embodiment of the present invention discloses an antenna system, comprising: an array antenna capable of receiving signals from multiple satellites to obtain multiple signal strength data, the array antenna including multiple working subarrays, each working subarray having multiple antennas; a dynamic adjustment module connected to the array antenna, the dynamic adjustment module being able to control the array antenna to face one of the satellites based on an initial transmit / receive direction data and a direction of arrival (DOA) data; and a tracking module connected to the array antenna and the dynamic adjustment module, wherein when the dynamic adjustment module loads the initial transmit / receive direction data, the tracking module can establish a candidate list from the multiple signal strength data using a minimum strength threshold, and select the satellite with the largest signal strength data from the candidate list as a target object; wherein, when the tracking module detects that the signal strength data of the target object is less than a predetermined strength threshold, the tracking module switches from the candidate list to other satellites as the target object; when the signal strength data of the target object is less than a predetermined strength threshold, the tracking module switches to other satellites from the candidate list ... When the tracking module detects that the signal strength data of the target object is greater than the predetermined strength threshold, the tracking module issues a calculation command; and a calculation module, connected to the array antenna, the tracking module, and the dynamic adjustment module, when receiving the calculation command, the calculation module uses multiple working subarrays to obtain multiple baseband signal data of the target object, and inputs the multiple baseband signal data into a subspace tracking method to obtain a principal feature vector data and a principal feature value data; the calculation module uses the principal feature vector data and the principal feature value data to input into a rotation-invariant technique parameter estimation method (ESPRIT) to obtain the arrival direction data of the target object; the calculation module uses each arrival direction data to replace the initial transmit / receive direction data, so that the dynamic adjustment module controls the array antenna to face the target object according to the arrival direction data.

[0009] In summary, the antenna control method and antenna system disclosed in the embodiments of the present invention can, through the design of "inputting each of the baseband signal data into a subspace tracking method to obtain a principal feature vector data and a principal feature value data", and "using the principal feature vector data and the principal feature value data into an ESPRIT to obtain an arrival direction data of the target object", the antenna control method and antenna system can calculate the current satellite position more instantly for signal tracking.

[0010] To further understand the features and technical content of this invention, please refer to the following detailed description and accompanying drawings. However, these descriptions and drawings are only for illustrating the invention and are not intended to limit the scope of protection of the invention in any way. Simple Explanation of the Diagram

[0011] Figure 1 is a schematic flowchart of the antenna control method according to the first embodiment of the present invention.

[0012] Figure 2 is a schematic flowchart of another step of the antenna control method according to the first embodiment of the present invention.

[0013] Figure 3 is a circuit block diagram of the antenna system according to the second embodiment of the present invention.

[0014] Figure 4 is a flowchart illustrating the steps of the antenna control method according to the third embodiment of the present invention.

[0015] Figure 5 is a circuit block diagram of the antenna system according to the fourth embodiment of the present invention.

[0016] Figures 6A and 6B are schematic flowcharts of the antenna system according to the fifth embodiment of the present invention. Implementation

[0017] The following specific embodiments illustrate the implementation of the "antenna control method and antenna system" disclosed in this invention. Those skilled in the art can understand the advantages and effects of this invention from the content disclosed in this specification. This invention can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of this invention. Furthermore, the accompanying drawings of this invention are for simple illustrative purposes only and are not depictions of actual dimensions; this is stated beforehand. The following embodiments will further describe the relevant technical content of this invention in detail, but the disclosed content is not intended to limit the scope of protection of this invention.

[0018] It should be understood that while terms such as "first," "second," and "third" may be used in this document to describe various components or signals, these components or signals should not be limited by these terms. These terms are primarily used to distinguish one component from another, or one signal from another. Furthermore, the term "or" as used herein should, as appropriate, include any combination of one or more of the related listed items.

[0019] In addition, if in the following description it is indicated that a specific diagram is referred to or as shown in a specific diagram, it is only to emphasize that most of the relevant content mentioned in the following description appears in that specific diagram, but does not limit the following description to refer only to that specific diagram.

[0020] [First Embodiment]

[0021] Referring to Figures 1 and 2, this embodiment provides an antenna control method that can be applied to an antenna system 100, enabling the antenna system 100 to more efficiently calculate the optimal satellite (position) for tracking. The antenna control method includes steps S101 to S123. It should be noted that any one of the above steps can be omitted or replaced with a reasonable variation depending on the designer's needs. The steps of the antenna control method are described below.

[0022] Step S101: Load initial transmit / receive direction data. In practice, the initial transmit / receive direction data can be established based on ephemeris data. Specifically, the antenna system 100 reads the ephemeris data and finds at least one satellite position near the location of the antenna system 100 to establish the initial transmit / receive direction data. Of course, the method of establishing the initial transmit / receive direction data is not limited to this. For example, the initial transmit / receive direction data can be the zenith azimuth of the current position of the antenna system 100.

[0023] Step S103: Using an array antenna 1 (of the antenna system 100), receive signals from multiple satellites (not shown) based on the initial transmit / receive direction data to obtain multiple signal strength data. Each of the signal strength data may be a signal-to-noise ratio (SNR), carrier-to-noise ratio (CNR), carrier-to-interference-to-noise ratio (CINR), received signal strength indication (RSSI), or signal-to-interference-plus-noise ratio (SINR).

[0024] In practice, the various signal strength data can be obtained using an eigenvalue decomposition.

[0025] Step S105: Establish a candidate list from the multiple signal strength data using a minimum strength threshold. Specifically, the antenna system 100, configured on a mobile vehicle, is constantly in a positional change relative to the satellite; therefore, the minimum strength threshold is a minimum tolerable value established for the effective use of the antenna system 100. That is, the minimum strength threshold can be adjusted under different conditions (e.g., the hardware specifications of the antenna system 100). More specifically, because the Direction of Arrival (DOA) data used to determine the satellite orientation cannot be accurately estimated when the signal strength is too low, the minimum strength threshold refers to the lowest standard that the antenna system 100 can calculate using subspace tracking and rotation-invariant parameter estimation methods (detailed later).

[0026] Accordingly, the candidate list can record multiple satellites that "have ideal signal strength relative to the position of the antenna system 100".

[0027] Step S107: Select the satellite with the highest signal strength data from the candidate list and define it as a target object. In other words, the antenna system 100 first selects the satellite with the strongest signal from the candidate list as the target for subsequent actions.

[0028] Step S108: Detect whether the signal strength data of the target object is greater than a predetermined strength threshold. Specifically, the predetermined strength threshold is a reasonable value established for the effective use of the antenna system 100, that is, the predetermined strength threshold is greater than the minimum strength threshold.

[0029] Specifically, if the signal strength data of the target object is less than the predetermined strength threshold, step S109 is executed. Conversely, if the signal strength data of the target object is greater than the predetermined strength threshold, step S111 is executed.

[0030] Step S109: Switch other satellites from the candidate list to serve as the target. Specifically, since the position of the antenna system 100 relative to the satellites is constantly changing, the satellite selected as the target from the candidate list may have suboptimal signal strength. Therefore, the antenna system 100 needs to switch other satellites from the candidate list to serve as the new target.

[0031] Step S111: Obtain a baseband signal data of the target object using the array antenna 1, and input the baseband signal data into a subspace tracking method to obtain a principal feature vector data and a principal feature value data. It is worth noting that the subspace tracking method in this embodiment is the Fast Approximate Power Iteration (FAPI) method. The subspace tracking method will be described using FAPI below, but this invention is not limited thereto. For example, the Fast Approximate Power Iteration method can also be replaced by other subspace tracking methods, such as MFAPI, FDPM, and PAST.

[0032] In addition, the baseband signal data can be obtained in practice by downconverting the received narrowband digital modulation signal. That is, the baseband signal data is obtained by the signal processing unit through frequency conversion and filtering, and analog-to-digital conversion (ADC) of the received raw satellite signal data (e.g., narrowband digital modulation signal).

[0033] Step S113: The principal eigenvector data and the principal eigenvalue data are input into a rotational invariance technique (ESPRIT) to obtain the direction of arrival (DOA) data of the target object. The DOA data can be azimuth, elevation, or line of sight.

[0034] Step S115: Adjust the beam according to the arrival direction data to track the target object.

[0035] Preferably, the antenna control method further includes the following steps:

[0036] Step S117: Detect whether the direction of arrival data exceeds an error range. The error range refers to whether the actual azimuth of the satellite and the calculated direction of arrival data are within half-power beamwidth (HPBW). However, this is not readily available in practice, so an alternative method is used. For example, an orthogonal matrix output by FAPI and a guidance matrix are projected to calculate the energy of a projection matrix, and an energy threshold for the projection matrix is ​​set to ensure the accuracy of the direction of arrival data.

[0037] Furthermore, when the direction of arrival data exceeds the error range, other satellites are switched from the candidate list to serve as the target (i.e., step S109 is executed again). Conversely, when the direction of arrival data is within the error range, the baseband signal data of the target is updated and the direction of arrival data is calculated to adjust the beam and track the target, i.e., steps S111-S115 are executed again. It should be noted that in the ESPRIT algorithm, the direction of arrival data is estimated using the received baseband signal data. However, when the antenna system 100 incorporates the principal feature vector data into ESPRIT, the antenna system 100 suffers from high computational load and high time consumption (especially in the case of multiple signal sources), leading to an increase in computation time and computational power.

[0038] Conversely, FAPI is an efficient algorithm used to quickly estimate the eigenvalues ​​and eigenvectors of a matrix. Therefore, applying FAPI can significantly improve the efficiency of eigenvalue decomposition. In this case, FAPI can estimate the principal eigenvalues ​​and eigenvectors of a matrix through a fast approximation, thereby reducing computation time.

[0039] Generally, when applying FAPI to ESPRIT, FAPI is first used to find the main eigenvalues ​​and corresponding eigenvectors of the baseband signal data. Then, these eigenvectors are used to perform rotationally invariant technical parameter estimation (ESPRIT) to obtain the direction of arrival data.

[0040] To compare the time taken by "using ESPRIT alone" and "applying FAPI to ESPRIT", Table 1 below presents the time results for actual calculation examples. Where O stands for Big O notation, N for the number of rows in the antenna matrix, M for the number of columns in the antenna matrix, and r for the number of satellite signals.

[0041] Table 1 algorithm ESPRIT FAPI & ESPRIT Root mean square error 0.00328 0.308 Time complexity O((NM) 3+(NM) 2r 2+NM+NM*log(NM)+2r+1) O(5r 2+8r+3MNr+2NM+1) Average loss 0 times 1.2 times Sampling interval 1 second 1 second Total number of samples 2395 times 2395 times Average execution time 0.145 seconds 0.015 seconds

[0042] As shown in Table 1, although the root mean square error (RMSE) of "using ESPRIT alone for calculation" is smaller than that of "using FAPI with ESPRIT for calculation," and "using FAPI with ESPRIT for calculation" involves an average loss, these results have little impact on the accuracy of the antenna system 100 in tracking satellites. Conversely, because the average execution time of "using FAPI with ESPRIT for calculation" is much shorter than that of "using ESPRIT alone for calculation" (especially, the difference in relative average execution time becomes more pronounced with a larger number of antennas), the antenna system 100 can update its satellite tracking frequency more frequently, resulting in more timely and accurate satellite tracking.

[0043] Additionally, it is worth noting that when the antenna system 100 is in a rapidly changing environment, the antenna system 100 may switch frequently while tracking the target object. For example, in a marine environment, the movement of ships can affect the antenna system, and the changes in signal strength data (e.g., SNR) can be more drastic than on land, leading to ping-pong effect switching problems. Therefore, the antenna control method may further include the following step S110.

[0044] Step S110: Detect whether the satellite to be switched meets a switching condition. When the satellite to be switched meets the switching condition, switch the satellite to be switched as the target object (i.e., execute step S108 again for detection). When the satellite to be switched does not meet the switching condition, do not use the satellite to be switched as the target object (i.e., execute step S109 again to select another satellite). The switching condition is: the signal strength data of the other satellites at each time point within a predetermined time interval is greater than the signal strength data of the target object before the switch.

[0045] For example, during the switching process, the signal strength data of the satellite to be switched (i.e., the other satellites) must be better than the signal strength data of the current satellite (i.e., the target object) for 5 consecutive seconds (i.e., the predetermined time interval) before the switching is performed.

[0046] Furthermore, when the antenna system 100 has determined the target object, the antenna system 100 can select either speed or accuracy as the priority by using some steps of the antenna control method. Specifically, the antenna control method further includes steps S121 to S123.

[0047] Step S121: Detect whether the signal strength data of the target object is greater than an adjustment threshold. If the signal strength data of the target object is greater than the adjustment threshold, proceed to step S122. If the signal strength data of the target object is less than the adjustment threshold, proceed to step S123.

[0048] Step S122: Receive signals using N times N antennas of the array antenna, where N is a positive integer not less than 2. That is, the signal received by the antenna system 100 is sufficiently significant, so the antenna system 100 needs a faster tracking speed (i.e., processing speed) to update the tracking satellite frequency more frequently.

[0049] Step S123: Receive signals using M times M antennas of the array antenna, where M is a positive integer not less than N. In other words, the signal received by the antenna system 100 is too weak, so the antenna system 100 needs to locate the target object more accurately.

[0050] For example, the array antenna has 16 by 16 antennas. When the signal strength data of the target object is greater than the adjustment threshold, 8 by 8 antennas from the array antenna 1 are used. The antenna system 100 using 8 by 8 antennas has a faster processing speed than using 16 by 16 antennas, but the half-power beamwidth (HPBW) of the antenna system 100 is increased.

[0051] Conversely, when the signal strength data of the target object is less than the adjustment threshold, 16 by 16 antennas in the array antenna 1 are used. Using 16 by 16 antennas provides more accurate direction-of-arrival data than using 8 by 8 antennas, but the computation time required by the antenna system 100 is increased.

[0052] [Second Embodiment]

[0053] Referring to Figure 3, this embodiment provides an antenna system 100, which can be used to execute the antenna control method of the first embodiment. That is, the operational relationships of the components of the antenna system 100 can be coordinated with the description of the first embodiment as needed. Next, the components of the antenna system 100 and their connection relationships will be described.

[0054] The antenna system 100 includes an array antenna 1, a dynamic adjustment module 2 connected to the array antenna 1, a tracking module 3 connected to the array antenna 1 and the dynamic adjustment module 2, and a computing module 4 connected to the array antenna 1, the tracking module 3 and the dynamic adjustment module 2.

[0055] The array antenna 1 can receive signals from multiple satellites to obtain multiple signal strength data. These signal strength data can be signal-to-noise ratio (SNR), carrier-to-noise ratio (CNR), carrier-to-interference-to-noise ratio (CINR), received signal strength indication (RSSI), or signal-to-interference-plus-noise ratio (SINR).

[0056] The dynamic adjustment module can control the array antenna to face one of the satellites based on an initial transmit / receive direction data and a direction of arrival (DOA) data. In practice, the dynamic adjustment module 2 uses ephemeris data to establish the initial transmit / receive direction data, but the present invention is not limited thereto. For example, the initial transmit / receive direction data can also be preset to the current zenith direction of the array antenna 1.

[0057] When the dynamic adjustment module 2 loads the initial transmit / receive direction data, the tracking module 3 can use a minimum strength threshold to establish a candidate list from multiple signal strength data, and select the satellite with the largest signal strength data from the candidate list as a target object.

[0058] When the tracking module 3 detects that the signal strength data of the target object is less than a predetermined strength threshold, the tracking module 3 switches to other satellites from the candidate list as the target object. Conversely, when the tracking module 3 detects that the signal strength data of the target object is greater than the predetermined strength threshold, the tracking module 3 issues a calculation command.

[0059] When the computing module 4 receives the computing command, it uses the array antenna 1 to obtain a baseband signal data of the target object, and inputs the baseband signal data into a subspace tracking method to obtain a principal feature vector data and a principal feature value data.

[0060] Furthermore, the computing module 4 can use the principal feature vector data and the principal feature value data to input into a rotational invariance technique (ESPRIT) to obtain the arrival direction data of the target object.

[0061] Accordingly, the computing module 4 can use the arrival direction data to replace the initial transmit / receive direction data, so that the dynamic adjustment module 2 controls the array antenna 1 to face the target object based on the arrival direction data.

[0062] Furthermore, when the antenna system 100 is in a rapidly changing environment, it may switch frequently while tracking the target object. Therefore, the tracking module 3 switches to another satellite as the target object after a switching condition is met. The switching condition is that the signal strength data of the other satellite at each time point within a predetermined time interval is greater than the signal strength data of the target object before the switch.

[0063] In addition, to ensure continuous and optimal satellite tracking, the antenna system 100 may also include a correction module 5 electrically coupled to the computing module 4 and the dynamic adjustment module 2.

[0064] Specifically, the correction module 5 can detect whether the direction of arrival data exceeds an error range. When the correction module 5 detects that the direction of arrival data exceeds the error range, it sends a correction command to the dynamic adjustment module 2, causing the dynamic adjustment module 2 to switch from the candidate list to another satellite as the target object. Conversely, when the correction module 5 detects that the direction of arrival data is within the error range, it sends a continuous command to the calculation module 4, causing the calculation module 4 to update the baseband signal data of the target object and calculate the direction of arrival data to adjust the beam and track the target object.

[0065] Preferably, in order to optimize either speed or accuracy based on the current state of the antenna system 100.

[0066] The computing module 4 can issue a first adjustment command to the array antenna 1 when the signal strength data of the target object is greater than an adjustment threshold, or a second adjustment command to the array antenna 1 when it is less than the adjustment threshold. Accordingly, when the array antenna 1 receives the first adjustment command, it receives data using N x N antennas (N is a positive integer not less than 2). When the array antenna 1 receives the second adjustment command, it receives data using M x M antennas (M is a positive integer not less than N). In other words, the array antenna 1 receives data using a small-scale or large-scale array based on the first and second adjustment commands.

[0067] [Third Embodiment]

[0068] As shown in Figure 4, this is another embodiment of the present invention. The antenna control method in this embodiment is similar to that in the first embodiment, and the similarities between the two embodiments will not be repeated. The antenna control method in this embodiment includes steps S201-S217. Steps S201-S210 in this embodiment are roughly the same as steps S101-S110 in the first embodiment. The main difference between this embodiment and the above-mentioned antenna control method is that the array antenna 1 is divided into multiple working subarrays 11 to obtain multiple baseband signal data of the target object. The multiple baseband signal data are then used to obtain multiple direction-of-arrival data for tracking. The specific descriptions of steps S208, S211-S217 are as follows:

[0069] Step S208: Detect whether the signal strength data of the target object is greater than a predetermined strength threshold. Wherein, if the signal strength data of the target object is less than the predetermined strength threshold, proceed to step S209. Conversely, if the signal strength data of the target object is greater than the predetermined strength threshold, proceed to step S211.

[0070] Step S211: When the signal strength data of the target object is greater than the predetermined strength threshold, the array antenna 1 distinguishes multiple working subarrays and uses the multiple working subarrays to obtain multiple baseband signal data of the target object respectively.

[0071] Step S213: Input each of the fundamental frequency signal data into a subspace tracking method to obtain a principal feature vector data and a principal feature value data.

[0072] Step S215: Use the principal eigenvector data and the principal eigenvalue data to input into a rotational invariance technique (ESPRIT) to obtain the direction of arrival (DOA) data of the target object.

[0073] Step S217: Adjust the beam and track the target object based on the multiple directions of arrival data.

[0074] The antenna control method can be based on a working order to select one of the loaded direction-of-arrival (DOA) data to adjust the beam. In practice, the working order can be established by ranking the values ​​of the signal strength data. For example, the DOA data with the highest signal strength value is used first to adjust the beam, the DOA data with the next highest signal strength value is used second, and so on. Alternatively, the working order can be adjusted based on a specific situation, such as arranging the values ​​of the signal strength data in an alternating manner. For example, if the four signal strength data values ​​are 5, 7, 9, and 3, the working order would be 9, 3, 7, 5. More specifically, the tolerances, material inhomogeneities, and assembly errors inherent in most array antennas can affect the accuracy of the DOA data when the ESPRIT algorithm calculates it, leading to errors in beam direction adjustment. Therefore, the antenna control method described in this embodiment can reduce the impact of overall phase deviation and shorten the overall beam adjustment time to a certain extent by dividing the array antenna into sections.

[0075] [Fourth Embodiment]

[0076] Referring to Figure 5, this embodiment provides an antenna system 100', which can be used to execute the antenna control method of the third embodiment. The antenna system 100' in this embodiment is similar to the antenna system 100 of the second embodiment. That is, the operational relationships of the components of the antenna system 100' can be coordinated with the descriptions of the second and third embodiments as needed. Next, the components of the antenna system 100' and their connection relationships will be described.

[0077] The antenna system 100' includes an array antenna 1, a dynamic adjustment module 2 connected to the array antenna 1, a tracking module 3 connected to the array antenna 1 and the dynamic adjustment module 2, and a computing module 4 connected to the array antenna 1, the tracking module 3 and the dynamic adjustment module 2.

[0078] The array antenna 1 can receive signals from multiple satellites to obtain multiple signal strength data. These signal strength data can be signal-to-noise ratio (SNR), carrier-to-noise ratio (CNR), carrier-to-interference-to-noise ratio (CINR), received signal strength indication (RSSI), or signal-to-interference-plus-noise ratio (SINR). The array antenna 1 includes multiple operating subarrays 11, and each operating subarray 11 has multiple antennas.

[0079] The dynamic adjustment module 2 can control the array antenna to face one of the satellites based on an initial transmit / receive direction data and a direction of arrival (DOA) data.

[0080] When the dynamic adjustment module 2 loads the initial transmit / receive direction data, the tracking module 3 can use a minimum strength threshold to establish a candidate list from multiple signal strength data, and select the satellite with the largest signal strength data from the candidate list as a target object.

[0081] Specifically, when the tracking module 3 detects that the signal strength data of the target object is less than a predetermined strength threshold, the tracking module 3 switches to another satellite from the candidate list as the target object. Conversely, when the tracking module 3 detects that the signal strength data of the target object is greater than the predetermined strength threshold, the tracking module 3 issues a calculation command.

[0082] When receiving the calculation command, the computing module 4 uses multiple working subarrays 11 to obtain multiple baseband signal data of the target object, and inputs these baseband signal data into a subspace tracking method to obtain principal eigenvector data and principal eigenvalue data. Furthermore, the computing module 4 uses the principal eigenvector data and the principal eigenvalue data to input into a rotation-invariant technique (ESPRIT) method to obtain the arrival direction data of the target object.

[0083] Accordingly, the computing module 4 can use the arrival direction data to replace the initial transmit / receive direction data, so that the dynamic adjustment module 2 controls the array antenna 1 to face the target object according to the arrival direction data.

[0084] Preferably, the computing module 4 compares multiple signal strength data to establish a working order, and the computing module 4 inputs the corresponding direction of arrival data according to the working order to replace the initial transmit / receive direction data.

[0085] [Fifth Embodiment]

[0086] As shown in Figures 6A and 6B, this is another embodiment of the present invention. The antenna control method in this embodiment is similar to the antenna control method in the first embodiment.

[0087] Step S301: Load initial transmit / receive direction data.

[0088] Step S303: Use an array antenna to receive signals from multiple satellites according to the initial transmit / receive direction data to obtain multiple signal strength data.

[0089] Step S305: Establish a candidate list from the multiple signal strength data using a minimum intensity threshold.

[0090] Step S307: Select two satellites from the candidate list that have the highest and second highest signal strength data, and define them as a first target object and a second target object, respectively. In this embodiment, the first target object is the one with the highest signal strength data, and the second target object is the one with the second highest signal strength data, but this is not a limitation of the present invention.

[0091] Step S308: Detect whether the signal strength data of the first target object and the second target object is greater than a predetermined strength threshold.

[0092] When the signal strength data of the first target object and the second target object are less than the predetermined strength threshold (i.e., both the signal strength data of the first target object and the signal strength data of the second target object are less than the predetermined strength threshold), step S309 is executed. Conversely, when the signal strength data of either the first target object or the second target object is greater than the predetermined strength threshold (i.e., one of the signal strength data of the first target object and the signal strength data of the second target object is less than the predetermined strength threshold), step S311 is executed.

[0093] Step S309: Switch other satellites from the candidate list to serve as the first target object or the second target object. For example, if the signal strength data of the first target object is greater than the predetermined strength threshold, switch other satellites from the candidate list to serve as the first target object. Of course, step S309 can be followed by step S310 as in step S110 of the first embodiment. That is, step S310 is: detecting whether the satellite to be switched meets a switching condition.

[0094] Step S311: Use the array antenna to obtain two baseband signal data of the first target object and the second target object, and input each baseband signal data into a subspace tracking method to obtain a principal feature vector data and a principal feature value data.

[0095] Step S313: Using the principal feature vector data and principal feature value data of the first target object, and the principal feature vector data and principal feature value data of the second target object, we input them into a rotational invariance technique (ESPRIT) to obtain a first direction of arrival data of the first target object and a second direction of arrival data of the second target object.

[0096] Step S314: Detect whether the angle difference between the first arrival direction data and the second arrival direction data is greater than a predetermined angle threshold. It should be specifically noted that "the angle difference is less than the predetermined angle threshold" means that the signals emitted by the first target object and the second target object almost overlap, resulting in interference. Conversely, "the angle difference is greater than the predetermined angle threshold" means that the signals emitted by the first target object and the second target object almost do not overlap and do not interfere with each other.

[0097] In other words, the predetermined angle threshold is crucial for achieving effective target differentiation. This predetermined angle threshold can be referenced to the half-power beam width (HPBW), which is the angular range covered when the beam gain drops to half its maximum value. Reasonably, the predetermined angle threshold can be set between 1 and 1.5 times the HPBW to meet the need to balance target differentiation accuracy and coverage during beam switching.

[0098] Furthermore, the main lobe width is a crucial indicator of beam pointing performance, determining the beam's gain effect on signals within a specific angle. When the angular difference between the first and second target objects is greater than the main lobe width, the beam can accurately align in a specific direction without affecting other targets. However, when the angular difference is less than the main lobe width, the first and second target objects may simultaneously be located within or near the main lobe, leading to signal overlap and preventing the antenna system 100 from distinguishing between different signal sources.

[0099] In other words, when the angle difference is less than the main lobe width of the beam, the beam's directivity cannot be effectively focused on a single target, resulting in insufficient gain in a specific direction. Simultaneously, overlapping signals will cause interference and degrade performance. Therefore, appropriately increasing the predetermined angle threshold to 1.5 times the main lobe width can enhance the beam's ability to distinguish between different targets and reduce signal interference between targets, thereby improving the system's stability and reliability in multi-target scenarios.

[0100] In practice, the predetermined angle threshold needs to be established based on the azimuth and elevation directions, and therefore can be referenced in 3GPP specification #TR 38.820.

[0101] When the angle difference is greater than the predetermined angle threshold, step S315A (and subsequent related steps) is executed. Conversely, when the angle difference is less than the predetermined angle threshold, step S315B is executed.

[0102] Step S315A: Adjust the two beams according to the first direction of arrival data and the second direction of arrival data to track the first target object and the second target object.

[0103] Step S315B: Adjust a beam based on the first direction of arrival data to track the first target object, and execute step S316A.

[0104] Step S316A: Select a satellite smaller than the second target object from the candidate list according to the sorting of the signal strength data and define it as a third target object.

[0105] Step S316B: The third target object replaces the second target object in steps S308 to S314 and is executed again. That is, when the angle difference between the first direction of arrival data of the first target object and the third direction of arrival data of the third target object is less than the predetermined angle threshold, the antenna control method will again select a satellite smaller than the third target object from the candidate list according to the sorting of the signal strength data, define it as a fourth target object, and repeat the same steps (and so on).

[0106] Preferably, the candidate list can be updated simultaneously during the execution of each step by the antenna system 100. For example, the antenna system 100 adds a thread to perform the steps of establishing and updating the candidate list. Accordingly, the candidate list can provide an immediate and up-to-date list of satellite candidates during the process of "finding new target objects".

[0107] [Technical Effects of the Embodiments of the Invention]

[0108] In summary, the antenna control method and antenna system disclosed in the embodiments of the present invention can, through the design of "inputting each of the baseband signal data into a subspace tracking method to obtain a principal feature vector data and a principal feature value data", and "using the principal feature vector data and the principal feature value data into an ESPRIT to obtain an arrival direction data of the target object", the antenna control method and antenna system can calculate the current satellite position more instantly for signal tracking.

[0109] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Therefore, all equivalent technical changes made based on the description and drawings of the present invention are included within the protection scope of the present invention.

[0110] S101~S123, S201~S217, S301~S314, S315A, S315B, S316A, S316B: Steps 100, 100': Antenna system 1: Array antenna 11: Working Subarray 2: Dynamically adjust the module 3: Tracking Module 4: Computing Module 5: Correction Module

Claims

1. An antenna control method applied to an antenna system, the control method comprising the following steps: loading initial transmit / receive direction data; using an array antenna to receive signals from multiple satellites according to the initial transmit / receive direction data to obtain multiple signal strength data; establishing a candidate list from the multiple signal strength data using a minimum strength threshold; selecting the satellite with the largest signal strength data from the candidate list as a target object; when the signal strength data of the target object is less than a predetermined strength threshold, switching other satellites from the candidate list to the target object; when the signal strength data of the target object is greater than the predetermined strength threshold, obtaining a baseband signal data of the target object using the array antenna, and inputting the baseband signal data into a subspace tracking method to obtain a principal eigenvector data and a principal eigenvalue data; inputting the principal eigenvector data and the principal eigenvalue data into a rotation-invariant parameter estimation method (Estimation of Signal Parameters via Rotational Invariance). In the Techniques (ESPRIT), a direction of arrival (DOA) data of the target object is obtained; and the beam is adjusted based on the DOA data to track the target object.

2. The antenna control method as described in claim 1, wherein, The initial transmit / receive direction data is established using ephemeris data.

3. The antenna control method as described in claim 1, wherein, When the signal strength data of the target object is greater than an adjustment threshold, it is received by N times N antennas of the array antenna, where N is a positive integer not less than 2; when the signal strength data of the target object is less than the adjustment threshold, it is received by M times M antennas of the array antenna, where M is a positive integer not less than N.

4. The antenna control method as described in claim 1, wherein, During the tracking of the target object, it is detected whether the direction of arrival data exceeds an error range; when the direction of arrival data exceeds the error range, other satellites are switched from the candidate list to the target object; when the direction of arrival data is within the error range, the baseband signal data of the target object is updated and the direction of arrival data is calculated to adjust the beam and track the target object.

5. The antenna control method as described in claim 1, wherein, After a switching condition is met, other satellites are switched to be the target object; the switching condition is that the signal strength data of the other satellites at each time point within a predetermined time interval are all greater than the signal strength data of the target object before the switch.

6. An antenna control method applied to an antenna system, the control method comprising the following steps: loading initial transmit / receive direction data; using an array antenna to receive signals from multiple satellites according to the initial transmit / receive direction data to obtain multiple signal strength data; establishing a candidate list from the multiple signal strength data using a minimum strength threshold; selecting the satellite with the largest signal strength data from the candidate list as a target object; when the signal strength data of the target object is less than a predetermined strength threshold, switching other satellites from the candidate list to serve as the target object; when the signal strength data of the target object is greater than the predetermined strength threshold, distinguishing multiple working subarrays using multiple antennas of the array antenna, and obtaining multiple baseband signal data of the target object using the multiple working subarrays respectively; inputting each baseband signal data into a subspace tracking method to obtain a principal eigenvector data and a principal eigenvalue data; inputting the principal eigenvector data and the principal eigenvalue data into a rotation-invariant parameter estimation method (Estimation of Signal Parameters via Rotational Invariance). In the Techniques (ESPRIT), a direction of arrival (DOA) data of the target object is obtained; the beam is adjusted and the target object is tracked based on multiple DOA data.

7. The antenna control method as described in claim 6, wherein, Compare multiple baseband signal data to establish a working order; load multiple directions of arrival data according to the working order to adjust the beam.

8. An antenna system, comprising: An array antenna can receive signals from multiple satellites to obtain multiple signal strength data. A dynamic adjustment module, connected to the array antenna, controls the array antenna to face one of the satellites based on initial transmit / receive direction data and direction of arrival (DOA) data. A tracking module, connected to the array antenna and the dynamic adjustment module, when the dynamic adjustment module loads the initial transmit / receive direction data, the tracking module can establish a candidate list from multiple signal strength data using a minimum strength threshold, and select the satellite with the highest signal strength data from the candidate list as a target object. Wherein, when the tracking module detects that the signal strength data of the target object is less than a predetermined strength threshold, the tracking module switches to other satellites from the candidate list as the target object; when the tracking module detects that the signal strength data of the target object is greater than the predetermined strength threshold, the tracking module issues a calculation command. A computing module is connected to the array antenna, the tracking module, and the dynamic adjustment module. When receiving the computing command, the computing module uses the array antenna to obtain a baseband signal data of the target object and inputs the baseband signal data into a subspace tracking method to obtain a principal eigenvector data and a principal eigenvalue data. The computing module uses the principal eigenvector data and the principal eigenvalue data into a rotation-invariant technique (ESPRIT) to obtain the direction of arrival data of the target object. The computing module uses the direction of arrival data to replace the initial transmit / receive direction data, so that the dynamic adjustment module controls the array antenna to face the target object based on the direction of arrival data.

9. The antenna system as described in claim 8, wherein, The dynamic adjustment module uses ephemeris data to establish the initial transmit / receive direction data.

10. The antenna system as claimed in claim 8, wherein, When the signal strength data of the target object is greater than an adjustment threshold, the computing module issues a first adjustment command to the array antenna; when the signal strength data of the target object is less than the adjustment threshold, the computing module issues a second adjustment command to the array antenna. When the array antenna receives the first adjustment command, the array antenna receives the command using N times N antennas, where N is a positive integer not less than 2; when the array antenna receives the second adjustment command, the array antenna receives the command using M times M antennas, where M is a positive integer not less than N.

11. The antenna system as described in claim 8, wherein, The antenna system also includes a correction module electrically coupled to the calculation module and the dynamic adjustment module, the correction module being able to detect whether the direction of arrival data exceeds an error range; When the correction module detects that the direction of arrival data exceeds the error range, the correction module sends a correction command to the dynamic adjustment module, causing the dynamic adjustment module to switch from the candidate list to other satellites as the target object; When the correction module detects that the direction of arrival data is within the error range, the correction module sends a continuous command to the calculation module, causing the calculation module to update the baseband signal data of the target object and calculate the direction of arrival data to adjust the beam and track the target object.

12. The antenna system as described in claim 8, wherein, The tracking module switches to other satellites as the target object after a switching condition is met; the switching condition is that the signal strength data of the other satellites at each time point within a predetermined time interval is greater than the signal strength data of the target object before the switch.

13. An antenna system, comprising: An array antenna capable of receiving signals from multiple satellites to obtain multiple signal strength data, the array antenna comprising multiple working subarrays, each of the working subarrays having multiple antennas; a dynamic adjustment module connected to the array antenna, the dynamic adjustment module controlling the array antenna to face one of the satellites based on an initial transmit / receive direction data and a direction of arrival (DOA) data; a tracking module connected to the array antenna and the dynamic adjustment module, the tracking module, when the dynamic adjustment module loads the initial transmit / receive direction data, using a minimum strength threshold to establish a candidate list from the multiple signal strength data, and selecting the satellite with the highest signal strength data from the candidate list as a target object; Specifically, when the tracking module detects that the signal strength data of the target object is less than a predetermined strength threshold, the tracking module switches other satellites from the candidate list to the target object; when the tracking module detects that the signal strength data of the target object is greater than the predetermined strength threshold, the tracking module issues a calculation command; and a calculation module, connected to the array antenna, the tracking module, and the dynamic adjustment module, when receiving the calculation command, uses multiple working subarrays to obtain multiple baseband signal data of the target object, and inputs the multiple baseband signal data into a subspace tracking method to obtain a principal feature vector data and a principal feature value data; the calculation module uses the principal feature vector data and the principal feature value data to input into a rotation-invariant technical parameter estimation method (Estimation of Signal Parameters via Rotational Invariance). In Techniques (ESPRIT), the arrival direction data of the target object is obtained; the calculation module uses each of the arrival direction data to replace the initial transmit / receive direction data, so that the dynamic adjustment module controls the array antenna to face the target object according to the arrival direction data.

14. The antenna system as claimed in claim 13, wherein, The computing module compares multiple signal strength data to establish a working order, and the computing module inputs the corresponding direction of arrival data according to the working order to replace the initial transmit / receive direction data.

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