Antenna attitude measurement method and device based on broadband satellite communication system, communication equipment and readable storage medium

Abstract

The invention relates to an antenna attitude measurement method and device based on a broadband satellite communication system, communication equipment, a computer readable storage medium and a computer program product. Wherein the antenna attitude coarse estimation is carried out through the AHRS to obtain a coarse estimation result of the antenna attitude; calculating a first beam coming direction of the satellite based on the position of the satellite and the position of the user terminal under the geocentric coordinate system, performing coordinate system conversion on the first beam coming direction to obtain a second beam coming direction, and adjusting a beam forming coefficient and an antenna attitude of a signal receiver of the user terminal to enable the antenna beam direction to be initially aligned with the first beam coming direction, enabling a receiver to receive a broadband satellite burst signal sent by a satellite, and processing the broadband satellite burst signal to obtain a baseband signal; and calculating the time difference of arrival of the broadband satellite burst signal received by the diagonal array element of the phased-array antenna, carrying out fusion processing on the time difference of arrival and the coarse estimation result of the antenna attitude to obtain a fine estimation result of the antenna attitude, and improving the estimation precision of the antenna attitude.

Description

Technical Field

[0001] The present application relates to the technical field of satellite communication, and particularly to an antenna attitude measurement method, device, communication equipment, computer-readable storage medium, and computer program product based on a broadband satellite communication system. Background Art

[0002] With the continuous development of satellite communication technology, a 5G non-terrestrial network (NTN) communication method has emerged. This method can achieve a wider network coverage for the 5G system and is an important development direction for mobile communication systems, especially satellite communication systems. In addition, in recent years, large-scale non-geosynchronous orbit (NGSO) satellite constellations have also been developing rapidly, providing conditions for achieving global coverage of satellite networks. Based on this, integrating NGSO satellites into the 5G system can fill the coverage gaps or service deficiencies of traditional 5G terrestrial networks in some areas and further improve the service quality and service scope of the 5G system.

[0003] Since NGSO satellites move around the Earth at high speeds, ground user terminals need to continuously adjust the direction of their phased array beams to achieve beam alignment and thus maintain satellite-ground communication. To achieve beam alignment, the user terminal needs to calculate the direction of maximum signal gain in the geocentric coordinate system based on its own position and the current satellite position; subsequently, it is necessary to transform this direction from the geocentric coordinate system to the antenna body coordinate system according to the antenna attitude information and achieve optimal reception through phased array beamforming technology. During this process, the antenna attitude information directly determines the accuracy of the beam pointing. Therefore, high-precision antenna attitude estimation is crucial for stable communication between the user terminal and the over-the-top satellite.

[0004] In traditional antenna attitude estimation methods, the carrier phase observations in the Global Navigation Satellite System (GNSS) are fused with the Inertial Measurement Unit (IMU). However, due to the low ground arrival power of GNSS signals and the fact that the information format is also public, the security of GNSS signals cannot be guaranteed in complex environments. In addition, due to the significant multipath effect, the corresponding carrier phase observations are easily affected by cycle slips, and the measurement results of the carrier phase are also unstable, resulting in poor accuracy of the obtained antenna attitude estimation results. Summary of the Invention

[0005] Based on this, it is necessary to provide an antenna attitude measurement method, device, communication device, computer-readable storage medium, and computer program product based on a broadband satellite communication system that can ensure high accuracy and real-time performance of antenna attitude estimation for the above technical problems.

[0006] In a first aspect, the present application provides an antenna attitude measurement method based on a broadband satellite communication system, including:

[0007] When the satellite appearance condition is met, perform a rough estimation of the antenna attitude through an AHRS to obtain a rough estimation result of the antenna attitude; and calculate the incoming direction of the first beam of the satellite based on the position of the satellite and the position of the user terminal in the geocentric coordinate system;

[0008] Based on the rough estimation result of the antenna attitude, perform a coordinate transformation on the incoming direction of the first beam to obtain the incoming direction of the second beam; and adjust the beamforming coefficient and antenna attitude of the signal receiver of the user terminal based on the incoming direction of the second beam so that the antenna beam direction is initially aligned with the incoming direction of the first beam, enabling the receiver to receive the broadband satellite burst signal sent by the satellite;

[0009] Process the broadband satellite burst signal through a radio frequency front end and a baseband signal receiver to obtain a baseband signal;

[0010] Calculate the time difference of arrival of the broadband satellite burst signal received by the diagonal array elements of the phased array antenna, and perform a fusion process on the time difference of arrival, the rough estimation result of the antenna attitude, and the output of the 9-axis IMU to obtain a fine estimation result of the antenna attitude.

[0011] In one embodiment, the satellite periodically broadcasts a broadband satellite burst signal to the user terminal on the ground. When the satellite appearance condition is met, performing a rough estimation of the antenna attitude through an AHRS to obtain a rough estimation result of the antenna attitude includes:

[0012] When a new satellite passes overhead appears, perform a rough estimation of the antenna attitude through an AHRS to obtain a rough estimation result of the antenna attitude.

[0013] In one embodiment, the method further includes:

[0014] Calculate the maximum gain direction of the received signal in the geocentric coordinate system based on the position of the satellite and the position of the user terminal; and perform a coordinate transformation on the maximum gain direction in the geocentric coordinate system through the fine estimation result of the antenna attitude to obtain the maximum gain direction in the antenna body coordinate system;

[0015] Based on the maximum gain direction in the antenna carrier coordinate system, adjust the beamforming coefficient of the antenna on the receiver or adjust the attitude of the antenna so that the antenna beam direction on the receiver is aligned with the maximum gain direction to receive the best signal from the satellite.

[0016] In one embodiment, the broadband satellite burst signal is received by the phased array antenna on the receiver; the processing of the broadband satellite burst signal by the RF front end and the baseband signal receiver to obtain a baseband signal includes:

[0017] Perform baseband signal processing on the broadband satellite burst signal transmitted by the satellite through the RF front end and the baseband signal receiver to obtain a baseband signal, and the baseband signal processing includes down-conversion processing, carrier synchronization processing, and frame synchronization processing.

[0018] In one embodiment, calculating the time difference of arrival of the broadband satellite burst signal received by the diagonal array elements of the phased array antenna, and performing fusion processing on the time difference of arrival, the rough estimation result of the antenna attitude, and the output result of the 9-axis IMU to obtain a fine estimation result of the antenna attitude, including:

[0019] Based on the rough estimation result of the antenna attitude and the antenna attitude at the previous moment, calculate the triaxial angular velocity estimation value; and based on the rough estimation result of the antenna attitude, calculate the signal arrival time difference estimation values of two groups of diagonal sub-arrays and the triaxial magnetic field strength estimation value;

[0020] Calculate the triaxial angular velocity factor through the triaxial angular velocity estimation value and the triaxial angular velocity output by the gyroscope in the 9-axis IMU;

[0021] Calculate the signal arrival time difference factor based on the signal arrival time difference estimation value and the signal arrival time difference measurement value;

[0022] Calculate the triaxial magnetic field strength factor through the triaxial magnetic field strength estimation value and the triaxial magnetic field strength output by the magnetometer in the 9-axis IMU;

[0023] Add the triaxial angular velocity factor, the signal arrival time difference factor, and the triaxial magnetic field strength factor to a preset attitude measurement factor graph for joint solution to obtain a fine estimation result of the antenna attitude.

[0024] In one embodiment, calculating the signal arrival time difference estimation values of two groups of diagonal sub-arrays based on the rough estimation result of the antenna attitude includes:

[0025] Based on the first coordinate of the satellite in the geocentric coordinate system and the center position of the phased array antenna of the receiver, perform processing to calculate the second coordinate of the satellite in the northeast celestial coordinate system, where the northeast celestial coordinate system takes the center position of the phased array antenna as the origin;

[0026] Convert the second coordinate to obtain the third coordinate of the satellite in the antenna carrier coordinate system;

[0027] Based on the speed of light, the third coordinate, the distances between the center positions of the elements in the phased array antenna and the center position of the phased array antenna, and the coordinates of each element in the antenna carrier coordinate system, perform processing to obtain the estimated values of the signal arrival time differences of each group of diagonal sub-arrays.

[0028] In a second aspect, the present application also provides an antenna attitude measurement device based on a broadband satellite communication system, including:

[0029] A first calculation module, configured to, when the satellite appearance condition is met, perform a rough estimation of the antenna attitude through an AHRS to obtain a rough estimation result of the antenna attitude; and calculate the first beam direction of the satellite based on the position of the satellite in the geocentric coordinate system and the position of the user terminal;

[0030] A first conversion module, configured to, based on the rough estimation result of the antenna attitude, perform a coordinate conversion on the first beam direction to obtain a second beam direction; and adjust the beamforming coefficient and the antenna attitude of the signal receiver of the user terminal based on the second beam direction, so that the antenna beam direction is initially aligned with the first beam direction, enabling the receiver to receive the broadband satellite burst signal sent by the satellite;

[0031] A first processing module, configured to process the broadband satellite burst signal through a radio frequency front end and a baseband signal receiver to obtain a baseband signal;

[0032] A second calculation module, configured to calculate the arrival time difference of the broadband satellite burst signal received by the diagonal elements of the phased array antenna, and perform a fusion process on the arrival time difference, the rough estimation result of the antenna attitude, and the output of a 9-axis IMU to obtain a fine estimation result of the antenna attitude.

[0033] In a third aspect, the present application also provides a communication device, including a memory and a processor, where the memory stores a computer program, and when the processor executes the computer program, the steps in the embodiments of the present application are implemented.

[0034] In a fourth aspect, the present application also provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps in the embodiments of the present application are implemented.

[0035] Fifth aspect, the present application also provides a computer program product, including a computer program which, when executed by a processor, implements the steps in the embodiments of the present application.

[0036] The above antenna attitude measurement method, device, communication equipment, computer-readable storage medium and computer program product based on a broadband satellite communication system, wherein the method includes: when the satellite appearance condition is satisfied, performing a rough estimation of the antenna attitude through an AHRS to obtain a rough estimation result of the antenna attitude; and calculating the incoming direction of the first beam of the satellite based on the position of the satellite and the position of the user terminal in the geocentric coordinate system; performing coordinate transformation on the incoming direction of the first beam based on the rough estimation result of the antenna attitude to obtain the incoming direction of the second beam; and adjusting the beamforming coefficient and the antenna attitude of the signal receiver of the user terminal based on the incoming direction of the second beam, so that the initial direction of the antenna beam is aligned with the incoming direction of the first beam, enabling the receiver to receive the broadband satellite burst signal sent by the satellite; processing the broadband satellite burst signal through a radio frequency front end and a baseband signal receiver to obtain a baseband signal; calculating the arrival time difference of the broadband satellite burst signal received by the diagonal array elements of the phased array antenna, and performing fusion processing on the arrival time difference, the rough estimation result of the antenna attitude and the output of the 9-axis IMU to obtain a fine estimation result of the antenna attitude.

[0037] By adopting this method, in the case of unstable GNSS data, attitude measurement can be performed through broadband satellite burst signals, and the arrival time difference of the signals is used as an observable quantity to perform fine-grained estimation of the antenna attitude, obtaining an estimation result of the antenna attitude with high precision, providing a reliable data basis for subsequent realization of optimal signal reception, and can also be combined with GNSS data to perform a fine estimation result of the antenna attitude, improving the comprehensiveness of antenna attitude estimation. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required to be used in the description of the embodiments of the present application or related technologies. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0039] Figure 1 It is an application environment diagram of the antenna attitude measurement method based on a broadband satellite communication system in an embodiment;

[0040] Figure 2 It is a schematic flowchart of the antenna attitude measurement method based on a broadband satellite communication system in an embodiment;

[0041] Figure 3Schematic flow chart of steps for determining the maximum gain direction of a received signal in an embodiment;

[0042] Figure 4 Schematic flow chart of steps for obtaining a fine estimation result of an antenna attitude in an embodiment;

[0043] Figure 5 Schematic flow chart of steps for calculating an estimated value of the time difference of arrival of a signal in an embodiment;

[0044] Figure 6 Schematic communication architecture diagram of an antenna attitude measurement method based on a broadband satellite communication system in another embodiment;

[0045] Figure 7 Schematic flow chart of an antenna attitude measurement method based on a broadband satellite communication system in another embodiment;

[0046] Figure 8 Schematic calculation process diagram for obtaining a fine estimation result of an antenna attitude in another embodiment;

[0047] Figure 9 Schematic diagram for obtaining a fine estimation result of an antenna attitude through a satellite measurement system in an embodiment;

[0048] Figure 10 Structural block diagram of an antenna attitude measurement device based on a broadband satellite communication system in an embodiment;

[0049] Figure 11 Internal structure diagram of a communication device in an embodiment. Detailed implementation manners

[0050] In order to make the objectives, technical solutions and advantages of the present application clearer and more understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0051] The antenna attitude measurement method based on a broadband satellite communication system provided by the embodiments of the present application can be applied to an application environment of a satellite communication system as shown in Figure 1 Among them, the satellite 102 can send a downlink beam to a plurality of user terminals 104 on the ground; the plurality of user terminals 104 can include, for example, user terminal 1, user terminal 2, user terminal 3... Figure 1Other user terminals are not shown; the user terminal 104 can process based on the received downlink beam. Among them, the user terminal 104 can be a phased array antenna with 4 array elements, and the antenna can also include an attitude and heading reference system (AHRS) and a satellite measurement system based on broadband satellite burst signals. The satellite measurement system based on broadband satellite burst signals is used to perform coarse estimation and fine estimation of the antenna attitude based on the input signal to obtain the fine estimation result of the antenna attitude. The specific modules included in this measurement system, the connection relationships between the modules, and the functions of each module will be described in detail in subsequent embodiments and will not be elaborated here.

[0052] The method of only relying on GNSS signals for antenna attitude estimation in the traditional technology cannot meet the antenna attitude measurement requirements in complex scenarios. The antenna attitude measurement method based on the broadband satellite communication system provided in this embodiment is a high-precision antenna attitude measurement method that does not rely on GNSS developed based on the characteristics and application requirements of the current 5G NTN network. It can still ensure the effectiveness and accuracy of antenna attitude estimation when GNSS is denied, and can also fuse with GNSS data when GNSS is working properly to further improve the system attitude estimation accuracy and comprehensively ensure the high accuracy of antenna attitude estimation.

[0053] In an exemplary embodiment, as Figure 2 shown, a method for measuring the antenna attitude based on a broadband satellite communication system is provided. Taking the application of this method to Figure 1 the user terminal 104 as an example, it includes the following steps 202 to 208. Among them:

[0054] Step 202, when the satellite appearance condition is met, perform coarse estimation of the antenna attitude through AHRS to obtain the coarse estimation result of the antenna attitude. And calculate the incoming direction of the first beam of the satellite based on the position of the satellite and the position of the user terminal in the geocentric coordinate system.

[0055] Among them, the specific scenario to which the embodiments of the present application are applied can be a scenario where a satellite broadcasts signals to multiple user terminals on the ground. For example, the satellite can periodically broadcast broadband burst signals to user terminals on the ground, that is, broadband satellite burst signals. An AHRS (Attitude and Heading Reference System) can be an attitude measurement system, which is used to make a preliminary estimate of the antenna attitude. The geocentric coordinate system is a coordinate system with the centroid of the earth as the origin; the position of the satellite is the position coordinate of the satellite that broadcasts broadband satellite burst signals to user terminals on the ground in the geocentric coordinate system; the position of the user terminal is the position of the terminal used to receive broadband satellite burst signals in the geocentric coordinate system. The satellite appearance condition can be pre-configured. For example, the satellite appearance condition can be the situation of a new over-the-horizon satellite, that is, the situation of a new satellite that broadcasts broadband satellite burst signals to user terminals on the ground. The beam direction of the satellite is the beam when the satellite broadcasts broadband satellite burst signals to each user terminal on the ground, and specifically can include one or more of azimuth angle data, elevation angle data, polarization mode data, and frequency data.

[0056] Specifically, the satellite can periodically broadcast broadband burst signals to user terminals on the ground. Before receiving the signals broadcast by the satellite, the user terminals on the ground can perform a rough estimate of the antenna attitude to obtain a rough estimate result of the antenna attitude. That is, after a new over-the-horizon satellite appears, it can be determined that the current satellite appearance condition is met. In this way, the user terminals on the ground can perform a rough estimate of the antenna attitude through the AHRS to obtain a rough estimate result of the antenna attitude. In addition, the user terminal can obtain the position of the currently appearing satellite in the geocentric coordinate system (which can be called the first position) and the position of the user terminal in the geocentric coordinate system (which can be called the second position); the user terminal can calculate the beam direction of the current satellite relative to the user terminal, that is, the first beam direction, based on the first position and the second position.

[0057] Step 204: Based on the rough estimate result of the antenna attitude, perform coordinate transformation on the first beam direction to obtain the second beam direction. And adjust the beamforming coefficient and antenna attitude of the signal receiver of the user terminal based on the second beam direction, so that the antenna beam direction is initially aligned with the first beam direction, enabling the receiver to receive the broadband satellite burst signals sent by the satellite.

[0058] Among them, the second beam direction can be the beam direction in the antenna body coordinate system; the signal receiver of the user terminal can include a phased array antenna, and the user terminal can receive the broadband satellite burst signals broadcast by the satellite, that is, the downlink signals of the satellite, through the phased array antenna of the receiver. For example, the phased array antenna of the receiver can include n array elements, and the received broadband satellite burst signals corresponding to the receiver can include n channels of signals, and n can be 4.

[0059] Specifically, the direction of arrival of the first beam can be in the geocentric coordinate system; the user terminal can construct a transformation matrix from the geocentric coordinate system to the antenna carrier coordinate system based on the rough estimation result of the antenna attitude, and calculate the direction of arrival of the first beam through this transformation matrix to obtain the direction vector of the direction of arrival of the first beam in the antenna carrier coordinate system, that is, the direction of arrival of the satellite beam in the antenna carrier coordinate system, that is, the direction of arrival of the second beam. The user terminal can adjust at least one of the beamforming coefficients of the phased array antenna on the receiver and the antenna attitude through the direction of arrival of the second beam to obtain an adjusted receiver, and the adjusted receiver can achieve alignment with the beam transmitted by the satellite, that is, alignment with the direction of arrival of the first beam of the satellite; after alignment, the receiver can receive the broadband satellite burst signal broadcast by the satellite, that is, the satellite downlink signal.

[0060] Step 206: Process the broadband satellite burst signal through the RF front end and the baseband signal receiver to obtain a baseband signal.

[0061] Among them, the RF front end can be an RF front end corresponding to the number of array elements included in the phased array antenna of the receiver. For example, in the case where the phased array includes 4 array elements, the corresponding RF front end can be a 4*4 RF front end, and the baseband signal receiver can be a baseband signal receiving module.

[0062] Specifically, the phased array antenna on the receiver corresponding to the user terminal can receive the satellite downlink signal (broadband satellite burst signal or RF signal or received signal), and input the received signal to the RF front end B1 (RF unit B1). The RF front end can perform down-conversion processing on the received signal to obtain an output signal, that is, the received signal after down-conversion processing, and input the received signal after down-conversion processing to the baseband signal receiver; the baseband signal receiver can perform processing such as carrier synchronization and frame synchronization on the received signal after down-conversion processing to obtain a baseband signal.

[0063] Step 208: Calculate the time difference of arrival of the broadband satellite burst signal received by the diagonal array elements of the phased array antenna, and perform fusion processing on the time difference of arrival, the rough estimation result of the antenna attitude, and the output of the 9-axis IMU to obtain a fine estimation result of the antenna attitude.

[0064] Among them, the time difference of arrival of the broadband satellite burst signal can be the time difference between the two diagonal sub-arrays on the phased array antenna receiving the broadband satellite burst signal, that is, the received arrival time difference of the two diagonal sub-arrays.

[0065] Specifically, the satellite measurement system can calculate the time difference of the broadband satellite burst signal received by two diagonal sub-arrays on the phased array antenna, calculate the time difference factor corresponding to the time difference, and calculate the three-axis angular velocity factor and the three-axis magnetic field strength factor through the rough estimation result of the antenna attitude and the output of the 9-axis IMU. Based on the above factors, an optimization solution process of the attitude measurement factor graph is carried out to obtain the fine estimation result of the antenna attitude. The output of the 9-axis IMU can include the output of the magnetometer in the 9-axis IMU, the output of the gyroscope, and so on.

[0066] In the above antenna attitude measurement method based on the broadband satellite communication system, in the case of unstable GNSS data, attitude measurement can be carried out through the broadband satellite burst signal, and the time difference of arrival of the signal is used as the observable to perform a fine-grained estimation of the antenna attitude, obtaining an estimation result of the antenna attitude with high precision, providing a reliable data basis for subsequent realization of the best reception of the signal, and can also be combined with GNSS data to perform a fine estimation result of the antenna attitude, improving the comprehensiveness of the antenna attitude estimation.

[0067] In an exemplary embodiment, the satellite periodically broadcasts broadband satellite burst signals to user terminals on the ground. The specific implementation process of the step "when the satellite appearance condition is met, perform a rough estimation of the antenna attitude through AHRS to obtain the rough estimation result of the antenna attitude" may include:

[0068] When a new over-the-horizon satellite appears, perform a rough estimation of the antenna attitude through AHRS to obtain the rough estimation result of the antenna attitude.

[0069] Specifically, the satellite can periodically broadcast broadband burst signals to user terminals on the ground. Before receiving the signals broadcast by the satellite, the user terminals on the ground can perform a rough estimation of the antenna attitude to obtain the rough estimation result of the antenna attitude. That is, after a new over-the-horizon satellite appears, it can be determined that the current satellite appearance condition is met. In this way, the user terminals on the ground can perform a rough estimation of the antenna attitude through AHRS to obtain the rough estimation result of the antenna attitude. Moreover, the user terminal can obtain the position of the currently appearing satellite in the geocentric coordinate system (which can be called the first position) and the position of the user terminal in the geocentric coordinate system (which can be called the second position); the user terminal can calculate the beam direction of the current satellite with respect to the user terminal based on the first position and the second position, that is, the first beam direction.

[0070] In one example, the sensors in the AHRS may include a three-axis gyroscope, a three-axis accelerometer, and a three-axis magnetometer, which are respectively used to measure the angular velocity of three coordinate axes, the acceleration in three axial directions, and the components of the earth's magnetic field in three axial directions; the satellite measurement system may collect data through sensors (such as a three-axis gyroscope, a three-axis accelerometer, and a three-axis magnetometer), and perform calculations on the collected data based on a preset calculation algorithm to obtain an estimated result of the current antenna attitude, that is, a rough estimated result of the antenna attitude. The preset calculation algorithm may include extended Kalman filter (EKF), complementary filter, and so on. The rough estimated result of the antenna attitude may be represented by quaternion, Euler angle, rotation matrix, and so on.

[0071] In this embodiment, by performing a rough estimation of the antenna attitude when a new over-the-top satellite appears, the receiving antenna of the user terminal can be quickly and timely adjusted, realizing the tracking and data transmission of the new over-the-top satellite, ensuring the timeliness of information reception, and also ensuring the stability of the strength and quality of the received signal.

[0072] In an exemplary embodiment, as Figure 3 shown, the antenna attitude measurement method based on the broadband satellite communication system further includes:

[0073] Step 302, based on the position of the satellite and the position of the user terminal, calculate the maximum gain direction of the received signal in the geocentric coordinate system. And through the fine estimation result of the antenna attitude, perform coordinate transformation on the maximum gain direction in the geocentric coordinate system to obtain the maximum gain direction in the antenna body coordinate system.

[0074] Specifically, the satellite measurement system can obtain the position of the satellite in the geocentric coordinate system and the position of the user terminal that is currently receiving the satellite downlink signal; for example, it can obtain the orbital parameters of the satellite and perform transformation on the orbital parameters to obtain the coordinates of the satellite in three axial directions in the geocentric coordinate system; the satellite measurement system can obtain the coordinates of the user terminal in the geocentric coordinate system through various positioning methods, such as GPS positioning method, Beidou positioning method, and so on; the satellite measurement system can calculate the direction vector from the satellite to the user terminal, and can also normalize the direction vector to obtain the unit direction vector from the satellite to the user terminal. In this way, when the satellite measurement system determines that the maximum gain direction of the phased array antenna of the receiver coincides with the unit direction vector, the gain of the received signal is the largest. Then, the satellite measurement system can perform transformation on the unit direction vector to obtain the polar coordinates corresponding to the unit direction vector, and the polar coordinates include the polar angle and azimuth angle of the antenna, that is, the maximum gain direction of the received signal in the geocentric coordinate system is obtained.

[0075] After obtaining the fine estimation result of the antenna attitude, the satellite measurement system can determine the attitude parameters of the antenna in the geocentric coordinate system based on the fine estimation result of the antenna attitude, and determine the transformation matrix corresponding to the attitude parameters for converting from the geocentric coordinate system to the antenna carrier coordinate system; in this way, the satellite measurement system can obtain the maximum gain direction of the received signal in the geocentric coordinate system, and calculate the multiplication result of the transformation matrix and the maximum gain direction of the received signal in the geocentric coordinate system, and determine the multiplication result as the maximum gain direction in the antenna carrier coordinate system.

[0076] Step 304, based on the maximum gain direction in the antenna carrier coordinate system, adjust the beamforming coefficient of the antenna on the receiver or adjust the attitude of the antenna, so that the antenna beam direction on the receiver is aligned with the maximum gain direction, and the best signal of the satellite can be received.

[0077] Specifically, the satellite measurement system can adjust the beamforming coefficient on the receiver or adjust the polarization angle and pitch angle of the phased array antenna on the receiver based on the polar angle and pitch angle included in the calculated maximum gain direction in the antenna carrier coordinate system, and adjust them to the angle parameters matching the maximum gain direction. In this way, when the satellite measurement system receives the satellite downlink signal through the adjusted receiver, it is aligned with the maximum gain direction of the satellite, so that the best satellite downlink signal can be received, that is, the satellite downlink signal with the highest signal quality and the highest signal strength can be received.

[0078] That is to say, based on the maximum gain direction in the antenna carrier coordinate system, adjusting the beamforming coefficient of the antenna on the receiver or adjusting the attitude of the antenna can make the maximum gain direction of the phased array antenna on the receiver aligned with the maximum gain direction of the received signal. In this way, the phased array antenna on the receiver can receive the best signal of the satellite.

[0079] In this embodiment, by performing coordinate transformation on the positions of the satellite and the terminal, the accuracy of the obtained maximum gain direction can be guaranteed, the estimation error of the antenna attitude can be avoided, the precise alignment between the antenna on the receiver and the satellite beam can be guaranteed, and the quality of the satellite signal received by the receiver can be further improved.

[0080] In an exemplary embodiment, the broadband satellite burst signal is received by the phased array antenna on the receiver; the broadband satellite burst signal is the satellite downlink signal broadcast by the satellite. The specific implementation process of the step "processing the broadband satellite burst signal through the RF front end and the baseband signal receiver to obtain the baseband signal" may include:

[0081] Performing baseband signal processing on the broadband satellite burst signal sent by the satellite through the RF front end and the baseband signal receiver to obtain the baseband signal, and the baseband signal processing includes down-conversion processing, carrier synchronization processing, and frame synchronization processing.

[0082] Among them, the RF front-end can be an RF front-end corresponding to the number of array elements included in the phased array antenna of the receiver. For example, when the phased array includes 4 array elements, the corresponding RF front-end can be a 4×4 RF front-end, and the baseband signal receiver can be a baseband signal receiving module.

[0083] Specifically, the phased array antenna on the receiver corresponding to the user terminal can receive the satellite downlink signal (broadband satellite burst signal or RF signal or received signal), and input the received signal to the RF front-end B1 (RF unit B1). The RF front-end can perform down-conversion processing on the received signal to obtain an output signal, that is, the received signal after down-conversion processing, and input the received signal after down-conversion processing to the baseband signal receiver; the baseband signal receiver can perform processing such as carrier synchronization and frame synchronization on the received signal after down-conversion processing to obtain a baseband signal.

[0084] In this embodiment, through the processing of the RF front-end and the baseband signal receiver, the accuracy of the obtained baseband signal can be guaranteed. Obtaining the baseband signal can facilitate subsequent signal transmission and implement various signal processing operations, and save the bandwidth resources used in subsequent signal transmission, realizing flexible, efficient, and low-cost communication.

[0085] In an exemplary embodiment, as Figure 4 shown, the specific implementation process of the step "calculate the time difference of arrival of the broadband satellite burst signal received by the diagonal array elements of the phased array antenna, and fuse the rough estimation result of the time difference of arrival and the antenna attitude with the output of the 9-axis IMU to obtain the fine estimation result of the antenna attitude" may include:

[0086] Step 402, calculate the three-axis angular velocity estimation value based on the rough estimation result of the antenna attitude and the antenna attitude at the previous moment. And calculate the signal arrival time difference estimation values of two groups of diagonal sub-arrays and the three-axis magnetic field strength estimation value based on the rough estimation result of the antenna attitude.

[0087] Among them, the current moment is the moment when a new over-the-horizon satellite appears, and the previous moment can be the previous moment of the current moment; the rough estimation result of the antenna attitude can be the rough estimation result of the antenna attitude output by the AHRS system. The rough estimation result of the antenna attitude can include the roll angle, pitch angle, and heading angle at the current moment k. The antenna attitude at the previous moment can include the roll angle, pitch angle, and heading angle at the previous moment k - 1. The output of the 9-axis IMU can include the output of the magnetometer in the 9-axis IMU, the output of the gyroscope, and so on.

[0088] Specifically, the satellite measurement system can calculate the time change amount Δ between the current moment k and the previous moment k - 1 t, and calculate the differences in roll angle, pitch angle, and heading angle between the current moment and the previous moment; and calculate based on the time variation and each of the differences to obtain the first change matrix of the antenna attitude, and calculate with the first change matrix based on the polar coordinates of the rough estimation result of the antenna attitude at the current moment k to obtain the triaxial angular velocity estimation values.

[0089] For example, the triaxial angular velocity estimation values can be calculated by the following formula

[0090]

[0091] Among them, the attitude information at the current moment k, that is, the rough estimation result of the antenna attitude at the current moment k is represented as χ k =(φ k , θ k , ψ k ) T ; φ k is the roll angle, θ k is the pitch angle, ψ k is the heading angle.

[0092] The satellite measurement system can calculate with the parallel data output by the triaxial magnetometer and the second change matrix of the antenna attitude to obtain the triaxial magnetic field strength estimation value M k . For example, it can be calculated by the following formula:

[0093]

[0094] Among them, M m =(M N , 0, M D ) T represents the output of the triaxial magnetometer when the antenna attitude coordinate system is parallel to the geomagnetic coordinate system, that is, the parallel data output by the triaxial magnetometer, and the second change matrix of the antenna attitude is

[0095] Step 404, calculate the triaxial angular velocity factor through the triaxial angular velocity estimation value and the triaxial angular velocity output by the gyroscope in the 9-axis IMU.

[0096] Among them, the triaxial angular velocity output by the gyroscope can be the measured value of the triaxial angular velocity.

[0097] Specifically, the satellite measurement system can calculate with the measured value of the triaxial angular velocity and the triaxial angular velocity estimation value to obtain the triaxial angular velocity factor. For example, the triaxial angular velocity factor can be calculated by the following formula

[0098]

[0099] Among them, is the measurement covariance matrix of the three-axis angular velocity; is the measured value of the three-axis angular velocity, and the measurement model of this measured value can be:

[0100]

[0101] Among them, is the measurement noise, is the rough estimation result χ of the antenna attitude based on the estimated value of the three-axis angular velocity and the current time k k and the antenna attitude information χ at the previous time k+1 is determined.

[0102] Step 406: Calculate the time difference of arrival factor based on the estimated value and the measured value of the time difference of arrival of the signal.

[0103] Specifically, the satellite measurement system can be obtained from the satellite downlink signal s received by the phased array antenna at the current time. The measurement model of the measured value of the time difference of arrival of this signal can be expressed as:

[0104]

[0105] Among them, is based on the second coordinate of the satellite in the northeast celestial coordinate system at the current time and the rough estimation result χ of the antenna attitude at the current time k k is determined, is the measurement noise.

[0106] For example, the time difference of arrival factor can be calculated by the following formula

[0107]

[0108] Among them, represents the measurement covariance matrix of the time difference of arrival.

[0109] Step 408: Calculate the three-axis magnetic field strength factor by the estimated value of the three-axis magnetic field strength and the three-axis magnetic field strength output by the magnetometer in the 9-axis IMU.

[0110] Specifically, the three-axis magnetic field strength output by the magnetometer at the current time in the satellite measurement system can be the measured value of the three-axis magnetic field strength. The satellite measurement system processes this measured value and the estimated value to obtain the three-axis magnetic field strength factor; this measured value of the three-axis magnetic field strength The measurement model is: Among them, can be obtained from the estimated value of the three-axis magnetic field strength; To measure noise.

[0111] Correspondingly, the triaxial magnetic field strength factor can be calculated by the following formula:

[0112]

[0113] Step 410: Add the triaxial angular velocity factor, the signal arrival time difference factor, and the triaxial magnetic field strength factor to the preset attitude measurement factor graph for joint solution to obtain a fine estimation result of the antenna attitude.

[0114] Specifically, the satellite measurement system can add the triaxial angular velocity factor, the signal arrival time difference factor, and the triaxial magnetic field strength factor to the preset attitude measurement factor graph to obtain a target equation, and solve the target equation to obtain a fine estimation result X* of the antenna attitude. For example, the target equation can be expressed by the following formula, that is, calculate the fine estimation result X* of the antenna attitude:

[0115]

[0116] In this embodiment, by performing a fine estimation of the antenna attitude based on the factor graph, the attitudes at multiple moments can be jointly solved based on the correlation of the attitudes at different moments, avoiding the influence of outliers and enhancing robustness.

[0117] In an exemplary embodiment, as Figure 5 shown, the specific processing process of the step "Based on the coarse estimation result of the antenna attitude, calculate the signal arrival time difference estimation values of two groups of diagonal sub-arrays" includes:

[0118] Step 502: Process based on the first coordinate of the satellite in the geocentric coordinate system and the center position of the phased array antenna of the receiver to calculate the second coordinate of the satellite in the northeast celestial coordinate system, where the northeast celestial coordinate system has the center position of the phased array antenna as the origin.

[0119] Step 504: Convert the second coordinate to obtain the third coordinate of the satellite in the antenna body coordinate system.

[0120] Among them, the geocentric coordinate system can be a coordinate system with the origin at the center of the Earth's mass, and the northeast celestial coordinate system has the center position of the phased array antenna as the origin; the second coordinate of the satellite in the northeast celestial coordinate system can be expressed as The third coordinate of the satellite in the antenna body coordinate system can be expressed as

[0121] Specifically, the satellite measurement system can use the first coordinate of the satellite in the geocentric coordinate system and the center position of the phased array antenna of the receiver Calculate the second coordinate of the satellite in the coordinate system with the center position of the antenna as the origin at the current moment. Calculate the coordinate transformation matrix between the northeast celestial coordinate system and the antenna body coordinate system, and calculate the third coordinate of the satellite in the antenna body coordinate system through this coordinate transformation matrix.

[0122] Optionally, the satellite measurement system can calculate the third coordinate through the following formula:

[0123]

[0124] where C(φ k , θ k , ψ k ) represents the coordinate transformation matrix, which can be specifically calculated through the following formula:

[0125]

[0126] Step 506: Based on the speed of light, the third coordinate, the distances between the center positions of each array element in the phased array antenna and the center position of the phased array antenna, and the coordinates of each array element in the antenna body coordinate system, perform processing to obtain the estimated signal arrival time differences of each group of diagonal sub-arrays.

[0127] Among them, the phased array antenna can be an antenna including 4 array elements, so there are 2 groups of diagonal array elements. The estimated signal arrival time differences of each group of diagonal sub-arrays can include the estimated signal arrival time difference τ 12 between array element 1 and array element 2, and the estimated signal arrival time difference τ 34 .

[0128] Specifically, for the estimated signal arrival time difference of the first group of diagonal sub-arrays, the satellite measurement system can calculate through the distance d between array element 1 and the phased array antenna, the distance d between array element 2 and the phased array antenna, the speed of light c, the coordinates of array element 1, the coordinates of array element 2, and the third coordinate to obtain the estimated signal arrival time difference of the first group of diagonal sub-arrays; based on a similar process, obtain the estimated signal arrival time difference of the second group of diagonal sub-arrays.

[0129] Optionally, it can be calculated through the following formula:

[0130]

[0131] where p i,b,k represents the coordinate of array element i in the antenna body coordinate system, and the coordinates of each antenna are respectively:

[0132] p 1,b,k = (0, d, 0) T p 2,b,k = (0, -d, 0) T,

[0133] p 3,b,k =(d, 0, 0) T , p 4,b,k =(-d, 0, 0) T

[0134] ‖·‖ represents the calculation of the vector norm length.

[0135] In this embodiment, by calculating the differences of multiple groups of diagonal array elements, the influence of noise, interference, and satellite clock error can be reduced, ensuring a relatively accurate estimated value of the signal arrival time difference and enhancing the robustness of the satellite measurement system.

[0136] The following, in combination with a specific embodiment, details the specific implementation process of the above antenna attitude measurement method based on a broadband satellite communication system, which may include:

[0137] As Figure 6 shown, it can be a schematic diagram of the specific application scenario of the antenna attitude measurement method based on a broadband satellite communication system provided in this embodiment. Among them, the satellite transmits a downlink beam to user terminal 1, user terminal 2, and user terminal 3 on the ground; the user terminal can receive the downlink beam; the user terminal is configured with a phased array antenna with 4 array elements and an AHRS. In this way, the satellite measurement system can process the satellite downlink signal received by the user terminal, the rough estimation result of the antenna attitude output by the AHRS, and the output of the 9-axis IMU to obtain the fine estimation result of the antenna attitude. The satellite measurement system can include a 4×4 MIMO RF front end, a baseband signal transmitter, a baseband signal receiver, an antenna control unit, an antenna attitude rough estimation module, and an antenna attitude fine estimation module. Finally, the satellite measurement system can output the fine estimation result of the antenna attitude.

[0138] In an example, the satellite periodically broadcasts broadband burst signals to user terminals on the ground. Before receiving the signal sent by a certain satellite (for example, a newly over-the-horizon satellite), the user terminal needs to perform a rough estimation of the antenna attitude through the AHRS. After obtaining the rough estimation result of the antenna attitude, the antenna attitude and the beamforming coefficient of the phased array antenna are adjusted to achieve beam initial alignment, so that the user terminal can receive the satellite downlink signal. The user receiver is equipped with a phased array antenna with 4 array elements. After completing the above beam initial alignment, the user receiver uses the phased array antenna to receive the broadband satellite burst signal. After the 4 signals are processed by the 4×4 MIMO RF front end and the baseband signal receiver, a baseband signal is obtained, and a fine estimation of the antenna attitude is performed based on this baseband signal to obtain the fine estimation result of the antenna attitude. The antenna control unit points the antenna to the direction with the maximum received signal gain through phased array beamforming according to the fine estimation result to achieve optimal reception, and realizes satellite tracking by continuously adjusting the antenna attitude.

[0139] As shown Figure 7 in the figure, it can be a specific application flowchart of the antenna attitude measurement method based on a broadband satellite communication system provided in this embodiment. The execution process is as follows:

[0140] S1. The user terminal performs a rough estimation of the antenna attitude through the AHRS. Specifically, when a new over-the-top satellite appears, the user terminal performs a rough estimation of the antenna attitude through the AHRS to obtain a rough estimation result of the antenna attitude.

[0141] S2. Calculate the incoming direction of the current satellite beam according to the satellite and user positions. Specifically, the satellite measurement system calculates the incoming direction of the current satellite beam, that is, the first beam incoming direction, through the user terminal based on the satellite position in the geocentric coordinate system and the own position of the user terminal.

[0142] S3. Convert the incoming direction of the satellite beam to the antenna body coordinate system by using the rough estimation result of the attitude. Specifically, according to the rough estimation result output by the AHRS, the first beam incoming direction in the geocentric coordinate system calculated in the above step S2 is converted to the antenna body coordinate system to obtain the second beam incoming direction.

[0143] S4. Realize the initial beam alignment by adjusting the beamforming technology or adjusting the antenna attitude. Specifically, the antenna control unit realizes the initial beam alignment by adjusting the beamforming coefficient and the antenna attitude, so that the user terminal can receive the satellite downlink signal.

[0144] S5. Use the 4-element phased array antenna to receive the satellite signal and perform signal processing. Specifically, after the user terminal receives 4 downlink signals by using the phased array antenna, the radio frequency front end and the baseband signal receiver are used to realize the baseband signal processing processes such as down-conversion, carrier synchronization, and frame synchronization to obtain 4 baseband signals.

[0145] S6. Calculate the time difference of arrival of the signals of two groups of diagonal array elements. Specifically, calculate the time difference of arrival of the signals received by the two groups of diagonal array elements in the 4 baseband signals respectively.

[0146] S7. Perform a fine estimation of the antenna attitude. Specifically, fuse the two time differences of arrival obtained in the above step S5 with the outputs of the magnetometer and gyroscope in the AHRS to realize a fine estimation of the antenna attitude and obtain a fine estimation result of the antenna attitude.

[0147] S8. Calculate the maximum gain direction of the received signal in the geocentric coordinate system according to the current satellite position and the user position.

[0148] S9. Achieve optimal reception by adjusting the beamforming coefficients or the antenna attitude; specifically, convert the maximum gain direction in the geocentric coordinate system calculated in the above steps to the antenna carrier coordinate system according to the fine attitude estimation result, and use the antenna control unit to align the phased array antenna with this maximum gain direction by adjusting the beamforming coefficients or the antenna attitude to achieve optimal reception. Continuously adjust the antenna attitude in this process to achieve satellite tracking.

[0149] As Figure 8 shown, it can be the specific process of obtaining the fine estimation result of the antenna attitude based on factor graph optimization:

[0150] S11. Calculate the estimated value of the three-axis angular velocity according to the rough attitude estimation result and the antenna attitude at the previous moment.

[0151] S12. Calculate the estimated values of the TDOA of two groups of signals; specifically, calculate the estimated values of the time difference of arrival of the signals of two diagonal sub-arrays according to the rough attitude estimation result.

[0152] S13. Calculate the estimated values of the three-axis magnetic field intensity according to the rough attitude estimation result.

[0153] S14. Calculate the three-axis angular velocity factor; specifically, calculate the three-axis angular velocity factor according to the estimated value of the three-axis angular velocity calculated in step S11 and the three-axis angular velocity output by the gyroscope.

[0154] S15. Calculate the TDOA factor; specifically, calculate the TDOA factor according to the two TDOA estimated values calculated in the above step S12 and the TDOA measurement value.

[0155] S16. Calculate the three-axis magnetic field intensity factor; specifically, calculate the three-axis magnetic field intensity factor according to the estimated value of the three-axis magnetic field intensity calculated in the above step S13 and the three-axis magnetic field intensity output by the magnetometer.

[0156] S17. Perform factor graph optimization to obtain the fine estimation result of the antenna attitude; specifically, add the factors at this moment obtained through the above steps to the attitude measurement factor graph, and jointly solve and output the fine estimation result of the attitude.

[0157] As Figure 9 shown, it can be the schematic diagram of the specific structure of the antenna attitude measurement system based on broadband satellite burst signals. This satellite measurement system can include a 4×4 RF front end B1, a baseband signal receiving module B2, a time difference of arrival estimation module B3, an antenna attitude rough estimation module B4, a time difference of arrival measurement value estimation module B5, a three-axis angular velocity measurement value estimation module B6, a magnetic field intensity measurement value estimation module B7, a time difference of arrival factor calculation module B8, a three-axis angular velocity factor calculation module B9, a magnetic field intensity factor calculation module B10, and an antenna attitude fine estimation module B11.

[0158] Among them, the connection relationship of the satellite measurement system can be as follows: the output of the 4×4 RF front-end B1 is connected to the baseband signal receiving module B2; the output of the baseband signal receiving module B2 is connected to the time difference of arrival estimation module B3; the time difference of arrival estimation module B3 is connected to the time difference of arrival factor calculation module B8; the antenna attitude rough estimation module B4 is connected to the time difference of arrival measurement value estimation module B5, the three-axis angular velocity measurement value estimation module B6, and the magnetic field strength measurement value estimation module B7; the time difference of arrival measurement value estimation module B5 is connected to the time difference of arrival factor calculation module B8; the three-axis angular velocity measurement value estimation module B6 is connected to the three-axis angular velocity factor calculation module B9; the magnetic field strength measurement value estimation module B7 is connected to the magnetic field strength factor calculation module B10; the time difference of arrival factor calculation module B8, the three-axis angular velocity factor calculation module B9, and the magnetic field strength factor calculation module B10 are connected to the antenna attitude fine estimation module B11.

[0159] 4×4 RF front-end module B1: The input of the RF unit B1 is the RF signal received by the phased array antenna; the output of the RF unit B1 points to the baseband signal receiving module B2; the RF unit B1 is used to down-convert the antenna received signal.

[0160] Baseband signal receiving module B2: The input of the baseband signal receiving module B2 is the RF unit B1; the output of the baseband signal receiving module B2 reaches the time difference of arrival estimation module B3; the baseband signal receiving module B2 is used to perform baseband signal processing processes such as carrier synchronization and frame synchronization on the down-converted received signal.

[0161] Time difference of arrival estimation module B3: The input of the time difference of arrival estimation module B3 is the baseband signal receiving module B2; the output of the time difference of arrival estimation module B3 points to the time difference of arrival factor calculation module B8; the time difference of arrival estimation module B3 is used to calculate the received time difference of arrival of the two diagonal sub-arrays according to the received baseband signal.

[0162] Antenna attitude rough estimation module B4: The output of the antenna attitude rough estimation module B4 reaches the time difference of arrival measurement value estimation module B5, the angular velocity measurement value estimation module B6, and the magnetic field strength measurement value estimation module B7; the antenna attitude rough estimation module B4 is used to perform rough estimation of the antenna attitude using the attitude and heading reference system (AHRS).

[0163] Time difference of arrival measurement value estimation module B5: The input of the time difference of arrival measurement value estimation module B5 is the antenna attitude rough estimation module B4; the output of the time difference of arrival measurement value estimation module B5 points to the time difference of arrival factor calculation module B8; the time difference of arrival measurement value estimation module B5 is used to calculate the estimated values of two sets of time difference of arrival measurement values according to the antenna attitude rough estimation result.

[0164] Angular velocity measurement value estimation module B6: The input of the angular velocity measurement value estimation module B6 is the antenna attitude rough estimation module B4; the output of the angular velocity measurement value estimation module B6 points to the three-axis angular velocity factor calculation module B9; the angular velocity measurement value estimation module B6 is used to calculate the estimated value of the three-axis angular velocity measurement value according to the antenna attitude rough estimation result.

[0165] Magnetic field intensity measurement value estimation module B7: The input of the magnetic field intensity measurement value estimation module B7 is the antenna attitude rough estimation module B4; the output of the magnetic field intensity measurement value estimation module B7 is the magnetic field intensity factor calculation module B10; the magnetic field intensity measurement value estimation module B7 is used to calculate the estimated value of the magnetic field intensity measurement value according to the antenna attitude rough estimation result.

[0166] Time difference of arrival factor calculation module B8: The input of the time difference of arrival factor calculation module B8 is the time difference of arrival estimation module B3 and the time difference of arrival measurement value estimation module B5; the output of the time difference of arrival factor calculation module B8 points to the antenna attitude fine estimation module B11; the time difference of arrival factor calculation module B8 is used to calculate the time difference of arrival factor according to two sets of time difference of arrival measurement values and measurement value estimated values.

[0167] Three-axis angular velocity factor calculation module B9: The input of the three-axis angular velocity factor calculation module B9 is the three-axis angular velocity measurement value output by the gyroscope and the angular velocity measurement value estimation module B6; the output of the three-axis angular velocity factor calculation module B9 points to the antenna attitude fine estimation module B11; the three-axis angular velocity factor calculation module B9 is used to calculate the three-axis angular velocity factor according to the three-axis angular velocity measurement value and the three-axis angular velocity measurement value estimated value.

[0168] Magnetic field intensity factor calculation module B10: The input of the magnetic field intensity factor calculation module B10 is the three-axis magnetic field intensity output by the magnetometer and the magnetic field intensity measurement value estimation module B7; the output of the magnetic field intensity factor calculation module B10 points to the antenna attitude fine estimation module B11; the magnetic field intensity factor calculation module B10 is used to calculate the magnetic field intensity factor according to the magnetic field intensity measurement value and the magnetic field intensity measurement value estimated value.

[0169] Antenna attitude fine estimation module B11: The input of the antenna attitude fine estimation module B11 is the time difference of arrival factor calculation module B8, the three-axis angular velocity factor calculation module B9, and the magnetic field intensity factor calculation module B10; the output of the antenna attitude fine estimation module B11 is the antenna attitude measurement fine estimation result; the antenna attitude fine estimation module B11 is used to calculate the antenna attitude measurement fine estimation result based on factor graph optimization.

[0170] The antenna attitude measurement method based on a broadband satellite communication system provided in this embodiment can avoid the instability of GNSS data and the problem that carrier phase observables are easily affected by cycle slips. It uses broadband satellite burst signals for attitude measurement and takes the time difference of arrival of burst signals as observables. With the increasing growth of satellite communication bandwidth, the estimation and measurement of the time difference of arrival of broadband satellite burst signals can already achieve an accuracy similar to that of GNSS carrier phase measurement, further improving the estimation accuracy of antenna attitude. The antenna attitude measurement method based on a broadband satellite communication system provided in this embodiment can also achieve fine estimation of attitude measurement based on a factor graph. By introducing the correlation of attitudes at different times, the attitudes at multiple times are jointly solved, which can effectively resist outliers and has strong robustness.

[0171] It should be understood that although the steps in the flowcharts involved in the above-described embodiments are shown sequentially according to the arrows, these steps do not necessarily have to be executed in the order indicated by the arrows. Unless there is a clear indication in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover, at least some of the steps in the flowcharts involved in the above-described embodiments may include multiple steps or multiple stages. These steps or stages do not necessarily have to be executed at the same time, but can be executed at different times. The execution order of these steps or stages does not necessarily have to be sequential, but can be executed alternately or in turn with at least some of the steps or stages in other steps or other steps.

[0172] Based on the same inventive concept, the embodiment of the present application also provides an antenna attitude measurement device based on a broadband satellite communication system for implementing the above-mentioned antenna attitude measurement method based on a broadband satellite communication system. The solution provided by this device to solve the problem is similar to the solution described in the above method. Therefore, the specific limitations in one or more embodiments of the antenna attitude measurement device based on a broadband satellite communication system provided below can refer to the limitations on the antenna attitude measurement method based on a broadband satellite communication system in the above text, and will not be repeated here.

[0173] In an exemplary embodiment, as Figure 10 shown, an antenna attitude measurement device 1000 based on a broadband satellite communication system is provided, including:

[0174] A first calculation module 1002, configured to, when the satellite appearance condition is satisfied, perform a rough estimation of the antenna attitude through an AHRS to obtain a rough estimation result of the antenna attitude; and calculate the incoming direction of the first beam of the satellite based on the position of the satellite and the position of the user terminal in the geocentric coordinate system;

[0175] The first conversion module 1004 is configured to perform coordinate conversion on the incoming direction of the first beam based on the rough estimation result of the antenna attitude to obtain the incoming direction of the second beam; and adjust the beamforming coefficient and the antenna attitude of the signal receiver of the user terminal based on the incoming direction of the second beam, so that the antenna beam direction is initially aligned with the incoming direction of the first beam, enabling the receiver to receive the broadband satellite burst signal sent by the satellite.

[0176] The first processing module 1006 is configured to process the broadband satellite burst signal through the RF front end and the baseband signal receiver to obtain a baseband signal.

[0177] The second calculation module 1008 is configured to calculate the time difference of arrival of the broadband satellite burst signal received by the diagonal array elements of the phased array antenna, and perform fusion processing on the time difference of arrival, the rough estimation result of the antenna attitude, and the output of the 9-axis IMU to obtain the fine estimation result of the antenna attitude.

[0178] In one embodiment, the satellite periodically broadcasts a broadband satellite burst signal to the user terminal on the ground. The first calculation module is specifically configured to:

[0179] In the case of a new over-the-horizon satellite, perform a rough estimation of the antenna attitude through the AHRS to obtain the rough estimation result of the antenna attitude.

[0180] In one embodiment, the device further includes:

[0181] The third calculation module is configured to calculate the maximum gain direction of the received signal in the geocentric coordinate system based on the position of the satellite and the position of the user terminal; and perform coordinate conversion on the maximum gain direction in the geocentric coordinate system through the fine estimation result of the antenna attitude to obtain the maximum gain direction in the antenna body coordinate system.

[0182] The first adjustment module is configured to adjust the beamforming coefficient of the antenna on the receiver or adjust the attitude of the antenna based on the maximum gain direction in the antenna body coordinate system, so that the antenna beam direction on the receiver is aligned with the maximum gain direction to receive the best signal of the satellite.

[0183] In one embodiment, the broadband satellite burst signal is received by the phased array antenna on the receiver. The first processing module is specifically configured to:

[0184] Perform baseband signal processing on the broadband satellite burst signal sent by the satellite through the RF front end and the baseband signal receiver to obtain a baseband signal, where the baseband signal processing includes down-conversion processing, carrier synchronization processing, and frame synchronization processing.

[0185] In one embodiment, the second calculation module is specifically configured to:

[0186] Calculate the triaxial angular velocity estimation value based on the rough estimation result of the antenna attitude and the antenna attitude at the previous moment; and calculate the signal arrival time difference estimation values of two groups of diagonal sub-arrays and the triaxial magnetic field strength estimation value based on the rough estimation result of the antenna attitude.

[0187] Calculate the triaxial angular velocity factor through the triaxial angular velocity estimation value and the triaxial angular velocity output by the gyroscope in the 9-axis IMU.

[0188] Calculate the signal arrival time difference factor based on the signal arrival time difference estimation value and the signal arrival time difference measurement value.

[0189] Calculate the triaxial magnetic field strength factor through the triaxial magnetic field strength estimation value and the triaxial magnetic field strength output by the magnetometer in the 9-axis IMU.

[0190] Add the triaxial angular velocity factor, the signal arrival time difference factor, and the triaxial magnetic field strength factor to a preset attitude measurement factor graph for joint solution to obtain the fine estimation result of the antenna attitude.

[0191] In one embodiment, the second calculation module is further specifically configured to:

[0192] Based on the first coordinate of the satellite in the geocentric coordinate system and the center position of the phased array antenna of the receiver, calculate the second coordinate of the satellite in the northeast celestial coordinate system, where the northeast celestial coordinate system takes the center position of the phased array antenna as the origin.

[0193] Convert the second coordinate to obtain the third coordinate of the satellite in the antenna body coordinate system.

[0194] Based on the speed of light, the third coordinate, the distances between the center positions of each array element in the phased array antenna and the center position of the phased array antenna, and the coordinates of each array element in the antenna body coordinate system, perform processing to obtain the signal arrival time difference estimation values of each group of diagonal sub-arrays.

[0195] Each module in the above antenna attitude measurement device based on a broadband satellite communication system can be implemented in whole or in part by software, hardware, and their combination. The above modules can be embedded in the processor of the communication device in hardware form or be independent of it, or can be stored in the memory of the communication device in software form, so that the processor can call and execute the operations corresponding to the above respective modules.

[0196] In one embodiment, a communication device is provided. Refer to Figure 11 . Figure 11 It is a schematic structural diagram of the terminal device provided by the embodiment of the present invention. Figure 11The terminal device 1100 shown includes: at least one processor 1101, a memory 1102, at least one network interface 1104, and a user interface 1103. Each component in the terminal device 1100 is coupled together through a bus system 1105. It can be understood that the bus system 1105 is used to implement the connection and communication between these components. In addition to including a data bus, the bus system 1105 also includes a power bus, a control bus, and a status signal bus. However, for the sake of clear illustration, in Figure 11 all kinds of buses are labeled as the bus system 1105. Additionally, in the embodiments of the present invention, a transceiver 1106 is further included. The transceiver can be multiple components, that is, including a transmitter and a receiver, and provides a unit for communicating with various other devices on a transmission medium.

[0197] Among them, the user interface 1103 may include a display, a keyboard, or a pointing device (such as a mouse, a trackball, a touchpad, or a touch screen, etc.).

[0198] It can be understood that the memory 1102 in the embodiments of the present invention can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchlink dynamic random access memory (SLDRAM), and direct rambus random access memory (DRRAM). The memory 1102 of the systems and methods described in the embodiments of the present invention is intended to include but not be limited to these and any other suitable types of memories.

[0199] In some embodiments, the memory 1102 stores the following elements, executable modules or data structures, or subsets thereof, or extended sets thereof: an operating system 11021 and application programs 11022.

[0200] Among them, the operating system 11021 includes various system programs, such as a framework layer, a core library layer, a driver layer, etc., and is used to implement various basic services and process hardware-based tasks. The application programs 11022 include various application programs, such as a MediaPlayer, a Browser, etc., and are used to implement various application services. The program for implementing the method of the embodiment of the present invention may be included in the application programs 11022.

[0201] In the embodiment of the present invention, by calling the program or instruction stored in the memory 1102, specifically, the program or instruction stored in the application programs 11022, wherein the processor is configured to, when the satellite appearance condition is met, perform a coarse estimation of the antenna attitude through an AHRS to obtain a coarse estimation result of the antenna attitude; and calculate a first beam direction of the satellite based on the position of the satellite and the position of the user terminal in the geocentric coordinate system; perform a coordinate transformation on the first beam direction based on the coarse estimation result of the antenna attitude to obtain a second beam direction; and adjust the beamforming coefficient and the antenna attitude of the signal receiver of the user terminal based on the second beam direction so that the antenna beam direction is initially aligned with the first beam direction, so that the receiver receives the broadband satellite burst signal sent by the satellite; process the broadband satellite burst signal through a radio frequency front end and a baseband signal receiver to obtain a baseband signal; calculate the arrival time difference of the broadband satellite burst signal received by the diagonal array elements of the phased array antenna, and perform a fusion process on the arrival time difference and the coarse estimation result of the antenna attitude to obtain a fine estimation result of the antenna attitude.

[0202] Some or all of the methods disclosed in the embodiments of the present invention can also be applied to the processor 1101, or implemented by the processor 1101, or implemented in cooperation with other components (such as a transceiver) by the processor 1101. The processor 1101 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the integrated logic circuit in the hardware of the processor 1101 or the instructions in the form of software. The above-mentioned processor 1101 may be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. It can implement or execute various methods, steps, and logic block diagrams disclosed in the embodiments of the present invention. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The steps of the method disclosed in combination with the embodiments of the present invention can be directly embodied as being executed and completed by the hardware decoding processor, or executed and completed by a combination of the hardware and software modules in the decoding processor. The software module may be located in a mature storage medium in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. This storage medium is located in the memory 1102, and the processor 1101 reads the information in the memory 1102 and combines its hardware to complete the steps of the above method.

[0203] It can be understood that the embodiments described in the embodiments of the present invention can be implemented by hardware, software, firmware, middleware, microcode, or a combination thereof. For hardware implementation, the processing unit can be implemented in one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays FPGAs, general-purpose processors, controllers, microcontrollers, microprocessors, other electronic units for performing the functions described in this application, or a combination thereof.

[0204] For software implementation, the technology described in the embodiments of the present invention can be implemented by executing modules (such as procedures, functions, etc.) that perform the functions described in the embodiments of the present invention. The software code can be stored in the memory and executed by the processor 1101. The memory can be implemented inside or outside the processor 1101.

[0205] In an exemplary embodiment, a communication device is provided, which includes a memory and a processor. A computer program is stored in the memory. When the processor executes the computer program, the following steps are implemented:

[0206] When the satellite appearance condition is satisfied, perform a rough estimation of the antenna attitude through an AHRS to obtain a rough estimation result of the antenna attitude; and calculate the incoming direction of the first beam of the satellite based on the position of the satellite and the position of the user terminal in the geocentric coordinate system;

[0207] Based on the rough estimation result of the antenna attitude, perform a coordinate transformation on the incoming direction of the first beam to obtain the incoming direction of the second beam; and adjust the beamforming coefficient and the antenna attitude of the signal receiver of the user terminal based on the incoming direction of the second beam, so that the initial direction of the antenna beam is aligned with the incoming direction of the first beam, and the receiver receives the broadband satellite burst signal sent by the satellite;

[0208] Process the broadband satellite burst signal through a radio frequency front end and a baseband signal receiver to obtain a baseband signal;

[0209] Calculate the time difference of arrival of the broadband satellite burst signal received by the diagonal array elements of the phased array antenna, and perform a fusion process on the time difference of arrival and the rough estimation result of the antenna attitude to obtain a fine estimation result of the antenna attitude.

[0210] Those skilled in the art can understand that Figure 11 the structure shown in

[0211] is only a block diagram of some structures related to the solution of the present application, and does not constitute a limitation on the communication device to which the solution of the present application is applied. The specific communication device may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0212] In an embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the embodiment of the present application are implemented.

[0213] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in the present application are all information and data authorized by the user or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with relevant regulations.

[0214] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The databases involved in the embodiments provided in the present application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the embodiments provided in the present application can be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, data processing logics based on quantum computing, artificial intelligence (AI) processors, etc., without limitation.

[0215] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope recorded in the present application.

[0216] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation to the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. An antenna attitude measurement method based on a broadband satellite communication system, characterized in that Applied to a satellite measurement system, the method includes: When the satellite appearance condition is met, performing a rough estimation of the antenna attitude through an AHRS to obtain a rough estimation result of the antenna attitude; and calculating the incoming direction of the first beam of the satellite based on the position of the satellite and the position of the user terminal in the geocentric coordinate system; Based on the rough estimation result of the antenna attitude, performing a coordinate transformation on the incoming direction of the first beam to obtain the incoming direction of the second beam; and adjusting the beamforming coefficient and the antenna attitude of the signal receiver of the user terminal based on the incoming direction of the second beam, so that the initial direction of the antenna beam is aligned with the incoming direction of the first beam, enabling the receiver to receive the broadband satellite burst signal sent by the satellite; Processing the broadband satellite burst signal through a radio frequency front end and a baseband signal receiver to obtain a baseband signal; Calculating the time difference of arrival of the broadband satellite burst signal received by the diagonal array elements of the phased array antenna, and performing a fusion process on the time difference of arrival, the rough estimation result of the antenna attitude, and the output of the 9-axis IMU to obtain a fine estimation result of the antenna attitude.

2. The method according to claim 1, wherein The satellite periodically broadcasts a broadband satellite burst signal to the user terminal on the ground. The step of performing a rough estimation of the antenna attitude through an AHRS to obtain a rough estimation result of the antenna attitude when the satellite appearance condition is met includes: When a new over-the-horizon satellite appears, performing a rough estimation of the antenna attitude through an AHRS to obtain a rough estimation result of the antenna attitude.

3. The method according to claim 2, wherein The method further includes: Calculating the direction of the maximum gain of the received signal in the geocentric coordinate system based on the position of the satellite and the position of the user terminal; and performing a coordinate transformation on the direction of the maximum gain in the geocentric coordinate system through the fine estimation result of the antenna attitude to obtain the direction of the maximum gain in the antenna body coordinate system; Based on the direction of the maximum gain in the antenna body coordinate system, adjusting the beamforming coefficient of the antenna on the receiver or adjusting the attitude of the antenna, so that the direction of the antenna beam on the receiver is aligned with the direction of the maximum gain, and the best signal of the satellite is received.

4. The method according to claim 1, wherein The broadband satellite burst signal is received by the phased array antenna on the receiver; The step of processing the broadband satellite burst signal through a radio frequency front end and a baseband signal receiver to obtain a baseband signal includes: Performing baseband signal processing on the broadband satellite burst signal sent by the satellite through a radio frequency front end and a baseband signal receiver to obtain a baseband signal, and the baseband signal processing includes down-conversion processing, carrier synchronization processing, and frame synchronization processing.

5. The method according to claim 1, wherein The step of calculating the time difference of arrival of the broadband satellite burst signal received by the diagonal array elements of the phased array antenna, and performing a fusion process on the time difference of arrival, the rough estimation result of the antenna attitude, and the output of the 9-axis IMU to obtain a fine estimation result of the antenna attitude includes: Calculating an estimated value of the three-axis angular velocity based on the rough estimation result of the antenna attitude and the antenna attitude at the previous moment; and calculating an estimated value of the time difference of arrival of the signals of two diagonal sub-arrays and an estimated value of the three-axis magnetic field intensity based on the rough estimation result of the antenna attitude. Calculate a three-axis angular velocity factor based on the three-axis angular velocity estimated value and the three-axis angular velocity output by the gyroscope in the 9-axis IMU; Calculate a time difference of signal arrival factor based on the estimated time difference of signal arrival value and the measured time difference of signal arrival; Calculate a three-axis magnetic field intensity factor based on the three-axis magnetic field intensity estimated value and the three-axis magnetic field intensity output by the magnetometer in the 9-axis IMU; Add the three-axis angular velocity factor, the time difference of signal arrival factor, and the three-axis magnetic field intensity factor to a preset attitude measurement factor graph for joint solution to obtain a refined estimation result of the antenna attitude.

6. The method according to claim 5, characterized in that, Based on the rough estimation result of the antenna attitude, calculate the estimated time difference of signal arrival of two diagonal sub-arrays, including: Process based on the first coordinate of the satellite in the geocentric coordinate system and the central position of the phased array antenna of the receiver to calculate the second coordinate of the satellite in the northeast celestial coordinate system, where the northeast celestial coordinate system takes the central position of the phased array antenna as the origin; Convert the second coordinate to obtain the third coordinate of the satellite in the antenna body coordinate system; Based on the speed of light, the third coordinate, the distances between the central positions of the array elements in the phased array antenna and the central position of the phased array antenna, and the coordinates of each array element in the antenna body coordinate system, perform processing to obtain the estimated time difference of signal arrival of each diagonal sub-array.

7. An antenna attitude measurement device based on a broadband satellite communication system, characterized in that, The device includes: A first calculation module, configured to, when the satellite appearance condition is satisfied, perform a rough estimation of the antenna attitude through an AHRS to obtain a rough estimation result of the antenna attitude; and calculate the first beam direction of the satellite based on the position of the satellite in the geocentric coordinate system and the position of the user terminal; A first conversion module, configured to perform a coordinate conversion on the first beam direction based on the rough estimation result of the antenna attitude to obtain a second beam direction; and adjust the beamforming coefficient and the antenna attitude of the signal receiver of the user terminal based on the second beam direction so that the antenna beam direction is initially aligned with the first beam direction, enabling the receiver to receive the broadband satellite burst signal sent by the satellite; A first processing module, configured to process the broadband satellite burst signal through a radio frequency front end and a baseband signal receiver to obtain a baseband signal; A second calculation module, configured to calculate the time difference of arrival of the broadband satellite burst signal received by the diagonal array elements of the phased array antenna, and perform a fusion process on the time difference of arrival, the rough estimation result of the antenna attitude, and the output of the 9-axis IMU to obtain a refined estimation result of the antenna attitude.

8. A communication device, comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the method according to any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the method according to any one of claims 1 to 6.

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