Beam pointing calibration method and apparatus for satellite communications

Abstract

The application provides a satellite communication beam pointing calibration method and device, which is applied to the technical field of satellite communication, and the method comprises the following steps: obtaining an uplink reference signal sent by a calibration terminal, wherein the calibration terminal is arranged at a known position on the ground; performing direction of arrival estimation based on the uplink reference signal to obtain an angle estimation value of the calibration terminal relative to a satellite array antenna; determining an angle calculation value of the calibration terminal relative to the satellite array antenna of the satellite based on a satellite coordinate of the satellite, a satellite attitude of the satellite and a calibration terminal coordinate of the calibration terminal; taking a difference value between the angle estimation value and the angle calculation value as a measurement value of a beam pointing deviation; and calibrating the beam pointing of the satellite based on the measurement value of the beam pointing deviation. The application can reduce the complexity of the satellite communication beam pointing calibration mode.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of satellite communication, in particular to a satellite communication beam pointing calibration method and device. BACKGROUND

[0002] Satellite beam pointing calibration is a process of ensuring the precise pointing of satellite antenna beams to target areas by adjusting antenna array parameters or satellite attitude. This process usually uses ground calibration stations to receive calibration signals transmitted by satellites, measures signal strength, phase difference or time difference, etc. to calculate the elevation and azimuth angle deviation of beam pointing, and then adjusts the phase weighting network of the antenna array, beam forming parameters or satellite attitude control system to compensate for pointing errors and achieve precise pointing control of the beam.

[0003] Traditional satellite beam pointing calibration methods rely heavily on ground measurement and control systems. Frequent instructions and measurement data need to be uploaded by ground stations, and the correction amount is calculated by the ground station and then uploaded to the satellite for execution. This method is cumbersome, time-consuming and occupies a lot of measurement and control resources. SUMMARY

[0004] The present application provides a satellite communication beam pointing calibration method and device to solve the problem of excessive dependence on ground calibration signals in the prior art, and to reduce the complexity of satellite communication beam pointing calibration.

[0005] The present application provides a satellite communication beam pointing calibration method, comprising the following steps. An uplink reference signal sent by a calibration terminal is obtained, wherein the calibration terminal is deployed at a known location on the ground; based on the uplink reference signal, the direction of arrival is estimated to obtain an angle estimation value of the calibration terminal relative to the satellite array antenna; based on the satellite coordinates of the satellite, the satellite attitude of the satellite and the calibration terminal coordinates of the calibration terminal, the angle calculation value of the calibration terminal relative to the satellite array antenna of the satellite is determined; the difference between the angle estimation value and the angle calculation value is taken as the measurement value of the beam pointing deviation; based on the measurement value of the beam pointing deviation, the beam pointing of the satellite is calibrated.

[0006] According to the satellite communication beam pointing calibration method provided by the application, the angle estimation value of the calibration terminal relative to the satellite array antenna is determined based on the satellite coordinates, the satellite attitude of the satellite and the calibration terminal coordinates of the calibration terminal, and the method comprises the following steps: a conversion relationship between an earth coordinate system and a satellite body coordinate system is constructed based on the satellite coordinates, the satellite attitude of the satellite and the calibration terminal coordinates of the calibration terminal; and the calibration terminal coordinates are projected to the satellite body coordinate system based on the conversion relationship, and the angle calculation value of the calibration terminal relative to the satellite array antenna of the satellite is determined.

[0007] According to the satellite communication beam pointing calibration method provided by the application, the beam pointing of the satellite is calibrated based on the measured value of the beam pointing deviation, and the method comprises one of the following: the weight of the beam forming vector of the satellite is corrected based on the measured value of the beam pointing deviation; and the satellite attitude of the satellite is corrected based on the measured value of the beam pointing deviation.

[0008] According to the satellite communication beam pointing calibration method provided by the application, the angle estimation value of the calibration terminal relative to the satellite array antenna is determined based on the satellite coordinates, the satellite attitude of the satellite and the calibration terminal coordinates of the calibration terminal, and the method comprises the following steps: a conversion relationship between an earth coordinate system and a satellite body coordinate system is constructed based on the satellite coordinates, the satellite attitude of the satellite and the calibration terminal coordinates of the calibration terminal; and the calibration terminal coordinates are projected to the satellite body coordinate system based on the conversion relationship, and the angle calculation value of the calibration terminal relative to the satellite array antenna of the satellite is determined.

[0009] According to the satellite communication beam pointing calibration method provided by the application, the calibration terminal and the user terminal adopt the same communication protocol and signal modulation mode, and the uplink reference signal is an uplink sounding reference signal.

[0010] According to the satellite communication beam pointing calibration method provided by the application, the number of the calibration terminals is multiple, and the method further comprises the following steps:

[0011] The measured value of the beam pointing deviation between each calibration terminal in the multiple calibration terminals and the satellite is determined, and a beam pointing deviation set is obtained; the target measured value is obtained by weighted summation based on the beam pointing deviation set; and the beam pointing of the satellite is calibrated based on the target measured value.

[0012] The application further provides a satellite communication beam pointing calibration device, comprising the following modules: a signal acquisition module, configured to acquire an uplink reference signal sent by a calibration terminal, wherein the calibration terminal is deployed at a known position on the ground; an angle estimation module, configured to perform direction of arrival estimation based on the uplink reference signal to obtain an angle estimation value of the calibration terminal relative to a satellite array antenna of a satellite; an angle calculation module, configured to determine an angle calculation value of the calibration terminal relative to the satellite array antenna of the satellite based on a satellite coordinate of the satellite, a satellite attitude of the satellite and a calibration terminal coordinate of the calibration terminal; a difference value determination module, configured to take a difference value between the angle estimation value and the angle calculation value as a measurement value of a beam pointing deviation; and a calibration execution module, configured to calibrate the beam pointing of the satellite based on the measurement value of the beam pointing deviation.

[0013] The application further provides an electronic device, comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the beam pointing calibration method of the satellite communication when executing the computer program.

[0014] The application further provides a non-transitory computer readable storage medium, having a computer program stored thereon, wherein the computer program is executable by a processor to implement the beam pointing calibration method of the satellite communication.

[0015] The application further provides a computer program product, comprising a computer program, wherein the computer program is executable by a processor to implement the beam pointing calibration method of the satellite communication.

[0016] The application provides the beam pointing calibration method and device of the satellite communication, which can enable the satellite to autonomously complete direction of arrival estimation by using the calibration terminal at a known position on the ground to send an uplink reference signal, and can directly obtain the beam pointing deviation by comparing the measured angle estimation value with the angle calculation value calculated according to the satellite attitude, the satellite position and the terminal position. Based on the deviation value, the satellite can autonomously complete beam pointing calibration in orbit, effectively solving the problem that the traditional method seriously depends on the ground measurement and control system for frequent data interaction and calculation, reducing the complexity of beam pointing calibration and improving the autonomy of satellite operation. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the application or prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0018] Figure 1 is a flowchart of a beam pointing calibration method of satellite communication provided by the present application.

[0019] Figure 2 is a schematic diagram of a satellite-side UPA subarray structure and a two-stage wave control structure provided by the present application.

[0020] Figure 3 is a multi-beam satellite communication schematic diagram provided by the present application.

[0021] Figure 4 is a module schematic diagram of a beam pointing calibration device of satellite communication provided by the present application.

[0022] Figure 5 is a flowchart of a beam pointing calibration device of satellite communication provided by the present application.

[0023] Figure 6 is a physical structure schematic diagram of an electronic device provided by the present application. DETAILED DESCRIPTION

[0024] To make the objectives, technical solutions, and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below with reference to the drawings in the present application. Obviously, the described embodiments are some embodiments of the present application, rather than all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0025] Satellite mobile communication systems have the characteristics of wide coverage, flexible networking, and being unaffected by natural disasters, and can provide high-bandwidth, flexible, and convenient Internet access services for users worldwide. Current satellite communication systems widely use multi-beam transmission technology, which simultaneously provides services for multiple users through multiple energy-concentrated point beams. In order to generate point beams, satellites need to be equipped with multi-beam antennas. Low-orbit earth satellites usually use phased array antennas, because phased array antennas can support wider angle coverage. Phased array antennas use beamforming networks to generate multiple concurrent high-gain directional beams, have flexible and wide scanning angles, can meet the requirements of wide-area coverage and wideband transmission, and can meet the requirements of multi-point access and communication, and thus become one of the cores of satellite communication systems. In addition, handset direct connection satellites allow handsets to directly communicate with satellites, thereby realizing voice, short message, and data transmission worldwide, providing satellite Internet services for a wide range of consumers, and gradually becoming a new hotspot of satellite mobile communication. Handset direct connection satellites use large-size on-board phased array antennas to increase antenna gain, so as to meet the link requirements of handset direct connection satellites.

[0026] However, after the satellite payload is launched into orbit, the high-precision pointing of the satellite antenna becomes a big problem, and the factors affecting the beam pointing include: satellite orbit error, satellite attitude error, coordinate transformation calculation precision, beam calculation error, mechanical processing error, array installation precision, and array deformation due to thermodynamic factors. The satellite beam pointing deviation will have a huge impact on the transmission performance of the system.

[0027] Taking a mobile phone direct satellite system with an orbital altitude of 500 km as an example, a beam pointing deviation of 0.2° leads to a beam deviation of nearly 2 km at the subsatellite point, and a beam deviation of nearly 3 km at the normal 54° position. In the mobile phone direct system, the diameter of the beam is very small, such as 10 km, so the beam pointing deviation will have a serious impact on the beam coverage. It is necessary to measure and calibrate the deviation of the satellite beam pointing.

[0028] The existing beam pointing deviation measurement and calibration methods include: measuring by using the downlink signal of the satellite: transmitting calibration signals by the gateway station or the satellite, and setting a beam calibration receiving station on the ground. The receiving station discriminates the energy of different beam calibration signals, calculates the power values of the received beam signals in the calibration group, and obtains the measurement value of the satellite antenna pointing deviation, which includes the azimuth deviation and the elevation deviation, and belongs to the satellite antenna coordinate system; the satellite-ground integrated satellite multi-beam calibration method: using the on-board calibration beam forming device, the ground calibration station, the control center and the satellite control station to realize, wherein the on-board calibration beam forming device is used to generate a multi-beam calibration signal containing the satellite attitude on orbit, and transmit it to the ground calibration station. The position error of the equal-power intersection point of the multi-beam calibration signal and the ground calibration station is used to calculate the deviation of the satellite attitude, so as to achieve the purpose of satellite-ground integrated calibration; the ground calibration station is used to receive the calibration signal generated on board, and measure the beam pointing deviation; the control center is used to analyze the pointing deviation, so as to determine whether to adjust the attitude; and the satellite control station is used to form an attitude adjustment instruction and inject it into the satellite for on-orbit attitude adjustment. The on-board calibration beam forming device includes an on-board beam calibration signal source, a beam calibration processor, a calibration beam amplitude and phase weighting network, and a calibration beam transmitting channel.

[0029] The existing method has the following technical defects: the beam pointing deviation measurement and calibration depend on the special calibration signal system, and cannot reuse the communication signals themselves, which increases the system complexity and cost.

[0030] The present application is directed to a low-orbit satellite communication constellation, and a beam pointing calibration method for satellite communication is proposed by using the signal characteristics in the communication system.

[0031] The beam pointing calibration method for satellite communication of the embodiments of the present application is applied to a satellite, and the satellite is configured with a satellite array antenna.

[0032] Figure 1This is a flowchart illustrating the beam pointing calibration method for satellite communication provided by the present invention, as shown below. Figure 1 As shown, the method includes the following steps.

[0033] Step 101: Obtain the uplink reference signal sent by the calibration terminal, wherein the calibration terminal is deployed at a known location on the ground.

[0034] In this embodiment of the invention, when the satellite performs beam index measurement, the beam is pointed at the calibration terminal.

[0035] Optionally, the calibration terminal is one or more dedicated communication devices pre-deployed at fixed locations on the Earth's surface. Its specific geographical location (longitude, latitude, and altitude, i.e., calibration terminal coordinates) is accurately determined through geodetic techniques (such as high-precision positioning and geodetic benchmark connection) and is stored in advance in the satellite's onboard database or can be obtained in real time / timed updates via satellite communication links.

[0036] The calibration terminal accesses the satellite network via uplink and downlink synchronization and periodically transmits uplink reference signals. Depending on the specific system requirements, the transmission power of the calibration terminal can be appropriately increased to improve the measurement accuracy of beam pointing error.

[0037] Step 102: Based on the uplink reference signal, perform direction of arrival estimation to obtain the angle estimate of the calibration terminal relative to the satellite array antenna.

[0038] After acquiring the digital baseband sample stream of the uplink reference signal sent by the calibration terminal, the satellite uses the spatial sampling capability of its configured satellite array antenna to estimate the direction of arrival (DOA). The specific process is as follows:

[0039] Optionally, the uplink reference signals received and synchronized by each element in the satellite array antenna can be preprocessed (e.g., element amplitude and phase correction, interference suppression, etc.) to obtain the preprocessed array signal;

[0040] The preprocessed array signal is segmented by time, and the spatial covariance matrix is ​​calculated for each segment. This matrix characterizes the spatial correlation between the received signals of each array element and is the core input for DOA estimation.

[0041] Based on the spatial covariance matrix, one of the following high-resolution direction-of-arrival estimation algorithms is used for angle calculation:

[0042] Subspace algorithms, such as multiple signal classification algorithms or rotation-invariant subspace algorithms, perform eigenvalue decomposition on the covariance matrix, construct a spatial spectral function using the orthogonality between the noise subspace and the signal steering vector, and determine the DOA by searching for the spectral peak positions.

[0043] Maximum likelihood algorithms, such as deterministic maximum likelihood or stochastic maximum likelihood, solve for the most likely signal incident direction through optimization modeling.

[0044] Beamforming algorithms, such as the Capon minimum variance distortionless response beamformer, suppress interference through adaptive weighting while scanning spatial angles and outputting the direction corresponding to the power peak.

[0045] The direction solution output by the selected algorithm is the angle estimate of the calibration terminal signal relative to the satellite array antenna coordinate system. The angle estimate is represented as a pair of estimated azimuth and estimated elevation angles, or stored as a unit direction vector.

[0046] It should be noted that this angle estimate is obtained entirely based on the physical layer characteristics (phase difference / amplitude difference) of the received signal through algorithm calculation, without using the satellite's own pose information or the terminal's position information.

[0047] Through the embodiments of the present invention, the satellite side uses the uplink reference signal to perform DOA estimation on the calibration terminal, and obtains the angle estimate of the calibration terminal relative to the satellite array antenna.

[0048] Step 103: Based on the satellite coordinates, satellite attitude, and calibration terminal coordinates, determine the calculated angle value of the calibration terminal relative to the satellite array antenna.

[0049] In this embodiment of the invention, three-dimensional geocentric rectangular coordinates are generated based on the geographical location (longitude, latitude, and elevation) of the calibration terminal; the Earth coordinate system is converted into the satellite body coordinate system by using satellite coordinates (spatial position vector) and attitude angle parameters (yaw angle, pitch angle, and roll angle) through a rotation matrix; and a rectangular coordinate system is established with the satellite array normal as the reference axis.

[0050] Optionally, a vector projection operation is performed in the array plane coordinate system to orthogonally project the position vector of the calibration terminal in the satellite body coordinate system to the antenna rectangular coordinate system; the calculated azimuth angle of the terminal relative to the normal direction of the satellite array is calculated based on the projection components; and the calculated elevation angle is determined based on the spatial distance between the terminal and the normal of the satellite array.

[0051] The calculated angle of the calibration terminal relative to the satellite array antenna (characterizing the normalized angular offset of the calibration terminal in the horizontal direction of the satellite array antenna) includes the calculated azimuth angle and the calculated elevation angle (characterizing the normalized angular offset of the terminal in the vertical direction of the satellite array antenna).

[0052] Through the embodiments of the present invention, the satellite side uses information such as satellite coordinates, satellite attitude, and calibration terminal coordinates to calculate the angle value of the calibration terminal relative to the satellite array antenna.

[0053] Step 104: The difference between the estimated angle value and the calculated angle value is used as the measured value of the beam pointing deviation.

[0054] In this embodiment of the invention, the angle estimate (DOA estimate) is the signal angle of arrival directly measured by the satellite through receiving the uplink signal from the calibration terminal, reflecting the actual pointing (azimuth and elevation) of the antenna. The angle calculation value is the theoretical pointing of the antenna calculated based on the satellite's own orbital coordinates (position), attitude parameters (pitch / yaw / roll angles), and known coordinates of the calibration terminal, through a geometric model (such as coordinate system transformation and vector operations).

[0055] The difference between the two (Δθ = estimated angle - calculated angle) is the measured value of beam pointing deviation, which includes the calculation error of track / attitude parameters (such as geometric model error caused by track position deviation) and the deviation between the actual antenna pointing and the theoretical model (such as installation error, thermal deformation, etc.).

[0056] In some embodiments, angle difference calculation is performed in the satellite body coordinate system to determine the difference between the estimated azimuth angle and the calculated azimuth angle, thereby obtaining the azimuth pointing deviation component; the difference between the estimated pitch angle and the calculated pitch angle is determined to obtain the pitch pointing deviation component; the azimuth pointing deviation component and the pitch pointing deviation component are integrated into a two-dimensional vector to characterize the overall offset of the beam pointing in the space plane (i.e., the measured value of the beam pointing deviation).

[0057] Through the embodiments of the present invention, the satellite side obtains the measured value of beam pointing deviation based on the difference between the estimated angle value and the calculated angle value.

[0058] Step 105: Based on the measured value of beam pointing deviation, calibrate the beam pointing of the satellite.

[0059] Based on actual needs, the beam pointing measurement cycle can be set. Within each cycle, multiple measurements can be performed, and the beam pointing can be continuously corrected using the measurement results to reduce beam pointing deviation.

[0060] This invention addresses the beam pointing deviation problem in low-Earth orbit satellite mobile communication systems by researching a pointing deviation measurement and calibration method based on reference terminal DOA (Angle of Arrival) estimation. This method eliminates the need for a dedicated ground calibration station and calibration signal, utilizing only a ground communication terminal and communication signal to measure satellite beam pointing deviation. Specifically, this invention proposes deploying one or more calibration terminals on the ground, with known locations and a configuration consistent with ordinary ground communication terminals. The satellite side uses the uplink signal from the calibration terminals to perform DOA estimation, obtaining an estimated angle value for the calibration terminals. Simultaneously, the satellite side uses satellite coordinate information, satellite attitude information, and calibration terminal coordinate information to obtain a calculated angle value for the calibration terminals. Due to satellite orbit and attitude accuracy issues, the calculated angle value from the reference terminal exhibits pointing deviation. The satellite side uses the estimated angle value and the calculated angle value to obtain a measured pointing deviation value. The satellite side then calibrates the satellite attitude or beam control direction based on the measured pointing deviation value.

[0061] This invention eliminates the need for a dedicated ground calibration station and calibration signals. Beam pointing deviation measurement is achieved solely using communication signals (such as uplink reference signals) between the ground terminal and the satellite base station, significantly reducing system complexity. Beam pointing measurement and calibration utilize only the uplink reference signal from the calibration terminal, and the measurement and calibration process has no impact on communication between the system and other user terminals. The measurement speed is fast, making it more adaptable to the high dynamic characteristics of low-Earth orbit satellites. Beam pointing deviation measurement results can be obtained through a single DOA estimation by the calibration terminal.

[0062] According to the beam pointing calibration method for satellite communication provided by the present invention, direction of arrival estimation is performed based on uplink reference signal to obtain an estimated angle value of the calibration terminal relative to the satellite array antenna, including:

[0063] Channel estimation is performed using the uplink reference signals of each channel of the satellite array antenna to obtain the channel estimation vector, which includes the array response vector of the calibration terminal.

[0064] Construct a spatial sampling matrix, where the dimension of the spatial sampling vector in the spatial sampling matrix is ​​the same as the dimension of the channel estimation vector, and the spatial sampling vector is the array response vector at different spatial angles;

[0065] Iterate through the spatial sampling matrix to calculate the correlation value between each spatial sampling vector and the channel estimation vector, and determine the index of the target sampling vector corresponding to the largest correlation value;

[0066] Spatial angle mapping is performed based on the target sampling vector index to obtain the estimated angle of the calibration terminal relative to the satellite array antenna.

[0067] Through the embodiments of the present invention, the key array response vector is obtained by channel estimation, a reasonable spatial sampling matrix is ​​constructed, and the target sampling vector index is determined by traversal calculation of relevant values ​​and the angle is mapped. This enables accurate and efficient acquisition of the calibration terminal angle, optimization of beam pointing calibration, and improvement of satellite communication system performance and multi-user communication capabilities.

[0068] This invention proposes a DOA estimation algorithm for subarray antennas and two-stage (two-level) beam control architectures widely used in low-Earth orbit satellites, which can significantly improve the measurement accuracy of beam pointing deviation.

[0069] The following example, using a subarray-based planar antenna and a two-stage beam control architecture, illustrates the specific algorithm for DOA estimation on the satellite side. The satellite side employs a uniform planar array (UPA) antenna, composed of multiple subarrays, which generates the receiving beam through two-stage beam control.

[0070] Satellite side in On the subcarrier, the ... The frequency domain uplink receive vector of the calibration terminal is composed of the uplink channel and the first calibration terminal. The array response vector of the calibration terminal on the satellite side, the first calibration terminal The calibration terminal in the first The frequency domain uplink transmission signal on the first subcarrier and the first It consists of frequency domain noise vectors of each subcarrier.

[0071] Assume the first The calibration terminal in the first The frequency domain uplink transmission signal on each subcarrier is The uplink received signal in the frequency domain on the satellite side can be expressed as:

[0072] (1)

[0073] in, Indicates the satellite side The calibration terminal in the first Frequency domain uplink receive vector on each subcarrier Indicates the first The calibration terminal in the first Uplink frequency domain channel response between subcarriers and satellite Indicates the first The array response vector of each calibration terminal on the satellite side. Indicates the first The calibration terminal in the first Frequency domain uplink transmission signal on each subcarrier Indicates the first Frequency domain noise vector of each subcarrier.

[0074] Based on the array response vector of the satellite array antenna in the corresponding direction, the estimated azimuth and estimated elevation angles of the calibration terminal relative to the satellite array antenna are obtained by combining the array response vectors in the x-axis and y-axis directions through the Kronecker product.

[0075] Indicates the first The array response vector of each calibration terminal on the satellite side, denoted as... For the first The departure angle of the satellite side corresponding to each calibration terminal, where, The first The array response vector can be expressed as follows: (The estimated azimuth and elevation angles of each calibration terminal relative to the satellite array antenna are given.) , where, for any ,have:

[0076] (2)

[0077] in, Indicates the direction of the satellite array antenna The array response vector, express The array response vector along the axis. express The array response vector along the axis. This represents the estimated azimuth angle of the calibration terminal relative to the satellite array antenna. This represents the estimated elevation angle of the calibration terminal relative to the satellite array antenna. It represents the Kronecker product.

[0078] The array response vectors in the x-axis and y-axis directions are both phase response vectors constructed based on the carrier wavelength, the number of array elements along the v-axis, and the spacing of the antennas along the v-axis.

[0079] for:

[0080] (3)

[0081] in, This represents the phase response vector of a satellite array antenna in a certain dimension. Indicates the angle parameter. Represent a A complex column vector of dimension 1 For carrier wavelength, Represents the imaginary unit. For array along The number of array elements along the axis, Let be the spacing of the antennas along the v-axis. Furthermore, Called calibration terminal From a physical perspective, and define the calibration terminal. The spatial angle is ,in , .

[0082] The satellite uses the uplink received signal to perform DOA estimation and obtain the angle of the calibration terminal. The satellite side uses a UPA antenna, which consists of multiple subarrays and generates a receiving beam through two-stage beam control.

[0083] refer to Figure 2 , Figure 2 This is a schematic diagram of the satellite-side UPA subarray structure and the two-stage wave control structure provided by the present invention. It includes: (a) and (b).

[0084] like Figure 2 As shown in (a), the satellite-side UPA consists of several smaller UPA subarrays, with the number of subarrays denoted on the x-axis and y-axis respectively. and The total number of subarrays is The number of antennas on the x-axis and y-axis in each subarray are respectively and Each subarray contains Root antenna, and satisfy , , .

[0085] like Figure 2 As shown in (b), the satellite generates beams through two stages of wave control. There are 1 receiving beams, of which the 1st beamforming network (BFN 1) uses the subarray within the beamforming network. The antenna performs beamforming, the first antenna... The first-level beamforming vector of the uplink receiving beam is Each subarray corresponds to a primary beam controller. The input of each primary beam controller is the received signal from each antenna of the corresponding subarray, and the output is the signal received by the primary beam controller. The received signal of the receiving beam; the second beamforming network (BFN 2) is used. Each subarray performs beamforming, the first... The secondary beamforming vector of the uplink receiving beam is The input of the secondary wave controller is from each primary wave controller. The received signal of each receiving beam is output as a secondary beam control signal. The received signal of the receiving beam. Beamforming vector of the uplink receive beam It can be represented as .

[0086] The formula for subarray index is ( , ),in, This represents a unique linear index of a subarray in a uniform planar array of satellites. Indicates that the subarray is in Position number in the axial direction express The total number of subarrays along the axial direction. Indicates that the subarray is in Position number in the axial direction express The total number of subarrays along the axis.

[0087] For a two-stage waveguide structure, the array response vector of each subarray to the calibration terminal is composed of the inter-subarray phase difference in the x-axis direction, the inter-subarray phase difference in the y-axis direction, and the Kronecker product of the first-stage waveguide response vector in the x-axis direction and the first-stage waveguide response vector in the y-axis direction.

[0088] For the Subarray, calibration terminal In the sub-array The array response vector on is:

[0089] (4)

[0090] in, Indicates calibration terminal In the The array response vector of each subarray, express Axial subarray position phase difference, express Axial subarray position phase difference, express The first-order wave control response vector in the axial direction, express The first-order wave control response vector in the axial direction.

[0091] v-axis direction ( The phase difference between subarrays is calculated based on the carrier wavelength, the spacing of the antennas in the v-axis direction, the position number of the subarrays in the v-axis direction, the number of antennas in the subarrays in the v-axis direction, and the spatial angle of the calibration terminal in the v-axis direction.

[0092] ( ) represents the phase difference between different subarrays along the v-axis, i.e.:

[0093] (5)

[0094] in, Represents the v-axis direction subarray phase difference, For carrier wavelength, Let be the spacing of the antennas along the v-axis. This indicates the position index of the subarray along the v-axis. This indicates the number of antennas in the subarray along the v-axis. Indicates calibration terminal Spatial angle in the v-axis direction.

[0095] The subarray response vector in the v-axis direction of the primary wave control is also constructed based on the carrier wavelength, the antenna spacing in the v-axis direction, the number of antennas in the subarray in the v-axis direction, and the spatial angle of the calibration terminal in the v-axis direction.

[0096] This is the subarray response vector in the first-level wave control, i.e.:

[0097] (6)

[0098] For the specific meanings of the parameters, please refer to the above text; they will not be repeated here.

[0099] The calibration terminal received by the subarray in the first The frequency domain signal on each subcarrier consists of the uplink channel response, the conjugate transpose of the beamforming weight vector of the first-level beam control, the array response vector of the subarray to the calibration terminal, the transmitted signal, and the noise term.

[0100] The following considers a method for DOA estimation using a reference signal. (Subarray) Received calibration terminal No. The frequency domain signal on each subcarrier is:

[0101] (7)

[0102] in, Subarray Received calibration terminal No. Frequency domain signal on each subcarrier Indicates calibration terminal In the Uplink frequency domain channel response on each subcarrier This represents the beamforming weight vector of the first-level beam control. Indicates the first Individual array calibration terminal The array response vector, Indicates calibration terminal In the Uplink transmission signals on each subcarrier Indicates calibration terminal In the The first subcarrier The frequency domain noise vector of each subarray.

[0103] After substituting the array response vector expression of the subarray, the frequency domain signal can be simplified to be represented by the equivalent channel response, the phase difference between subarrays in the x-axis direction, the phase difference between subarrays in the y-axis direction, the transmitted signal, and the noise term.

[0104] Among them, the first in formula (4) The array response vector of each subarray For calibration terminal Substituting the array response vector into formula (7), we get:

[0105] (8)

[0106] in, .

[0107] The multi-subarray composite signal vector, which contains the received signals of all subarrays, consists of the equivalent channel response, the Kronecker product of the second-level waveguide array response vector in the x-axis direction and the second-level waveguide array response vector in the y-axis direction, the transmitted signal, and the noise term.

[0108] Let vector To include all Calibration terminal received by each subarray No. The received signal on each subcarrier, namely:

[0109] (9)

[0110] in, Indicates all Calibration terminal received by each subarray No. The received signal on each subcarrier (i.e., the multi-subarray composite signal). Indicates the total number of subarrays. This indicates the received signal of the first subarray (for the calibration terminal). The (subcarriers) Represents the equivalent channel response. This represents the response vector of the second-level waveguide array along the x-axis. This represents the response vector of the second-level waveguide array along the y-axis. Indicates calibration terminal The uplink transmission signal, This indicates the noise term.

[0111] The response vector of the secondary waveguide array in the v-axis direction is composed of the phase difference of each subarray in the v-axis direction, which contains the spatial angle information of the calibration terminal.

[0112] The inter-array response vector along the v-axis corresponding to the second-level wave control can be expressed as:

[0113] (10)

[0114] From formula (5), Includes calibration terminal Spatial angle information.

[0115] The satellite uses multi-subarray synthesized signals to perform channel estimation on the calibration terminal. The resulting channel estimation vector includes the equivalent channel response, the Kronecker product of the second-level waveguide array response vector in the x-axis direction and the second-level waveguide array response vector in the y-axis direction, and the channel estimation error.

[0116] Use received signal For calibration terminal Channel estimation is performed, and the channel estimation results of the calibration terminal on each subarray are obtained. for:

[0117] (11)

[0118] in, This represents the channel estimation error. As can be seen from formula (11), the channel estimation result includes the array response vector between the subarrays corresponding to the second-level wave controller.

[0119] The spatial sampling vector and the inter-subarray response vector corresponding to the secondary wave control have the same structure. Its v-axis component is constructed based on the carrier wavelength, the spacing of the antennas in the v-axis direction, the number of antennas in the v-axis direction of the subarray, the total number of subarrays in the v-axis direction, and the spatial angle of the spatial sampling point in the v-axis direction.

[0120] Constructing a spatial sampling matrix ,in, The number of spatial sampling points. and Let be the number of spatial sampling points along the x-axis and y-axis, respectively. Let the spatial sampling matrix be denoted as... The Column (number) (a spatial sampling vector) is ,in for:

[0121] (12)

[0122] in, express Spatial sampling vector along the axis, Let be the spacing of the antennas along the v-axis. For carrier wavelength, This indicates the number of antennas in the subarray along the v-axis. This represents the total number of subarrays along the v-axis. Indicates the first The spatial angle of each spatial sampling point along the v-axis.

[0123] The satellite iterates through the spatial sampling matrix to calculate the correlation value between each spatial sampling vector and the channel estimation result vector, and determines the target sampling vector index corresponding to the largest correlation value.

[0124] Comparing formulas (12) and (10), it can be seen that the spatial sampling vector and the inter-array response vector corresponding to the second-level beam control have the same structure. Therefore, by traversing each spatial sampling vector, its relationship with the channel estimation result is calculated. The spatial angle corresponding to the spatial sampling vector with the largest correlation value is the calibration terminal. The spatial angle estimate. Let the index of the spatial sampling vector that maximizes the correlation value be denoted as . ,Right now:

[0125] (13)

[0126] in, Indicates calibration terminal The optimal spatial sampling index, Indicates the total number of spatial sampling points. Represents the conjugate transpose of the spatial sampling vector. Indicates calibration terminal The channel estimation results, This represents the subcarrier expectation operation.

[0127] Spatial angle mapping is performed based on the target sampling vector index to obtain the angle estimate of the calibration terminal relative to the satellite array antenna, namely the x-axis spatial angle estimate and the y-axis spatial angle estimate.

[0128] Calibration terminal The estimated value of the x-axis spatial angle is The estimated value of the y-axis spatial angle is ,in, .in, and These represent the spatial sampling vectors that maximize the correlation value. shaft and Index of the axis direction.

[0129] In practice, since the satellite side knows information such as satellite coordinates, satellite attitude, and calibration terminal coordinates, the spatial angle of the terminal can be calculated. However, due to problems such as satellite orbit error, attitude error, and structural error, the beam pointing will deviate. This deviation is generally within a limited range, and thus the search set of spatial sampling vectors can also converge to a limited range, which can greatly reduce the complexity of the search.

[0130] According to the present invention, a beam pointing calibration method for satellite communication calibrates the beam pointing of a satellite based on a measured value of beam pointing deviation, including one of the following:

[0131] The weights of the satellite's beamforming vector are corrected based on measurements of beam pointing deviation.

[0132] The satellite's attitude is corrected based on measurements of beam pointing deviation.

[0133] In this embodiment of the invention, the beam pointing deviation measurement can be used to correct the beam pointing in one of two ways. First, the beam pointing deviation measurement is fed back to the satellite attitude and orbit control module as a correction parameter to improve the control accuracy of the satellite's attitude and orbit. Second, the beam pointing deviation measurement is used to correct the beamforming vector. The beam pointing deviation measurement is used as a feedback quantity to correct the on-board beam pointing control model. For example, in the beam control algorithm of a phased array antenna, the beam pointing deviation measurement is used as a compensation quantity to adjust the weights, making the actual pointing direction approximate the theoretical design direction.

[0134] In some embodiments, the satellite inputs the measured value of the beam pointing deviation into the satellite carrier control processor, which generates phase compensation weights based on the deviation value and adjusts the phase offset of each antenna element in real time. For example, this is executed step by step through a two-level beam control architecture: the first-level beam control distributes the compensation weights to each antenna element within the subarray; the second-level beam control coordinates the overall phase relationship between subarrays and eliminates coupling errors.

[0135] In some embodiments, the satellite attitude and orbit control system receives measurements of beam pointing deviation and converts them into attitude correction parameters. The attitude and orbit control system then drives a cooled gas thruster or momentum wheel to adjust the satellite's pitch / yaw angle according to the correction parameters.

[0136] Through the embodiments of the present invention, based on the measured value of beam pointing deviation, the beamforming vector weight can be accurately corrected, improving resource utilization efficiency and reducing costs; it can also correct the satellite attitude, ensuring stable and reliable satellite communication.

[0137] According to a beam pointing calibration method for satellite communication provided by the present invention, based on the satellite coordinates, the satellite attitude, and the calibration terminal coordinates, the method determines the calculated angle value of the calibration terminal relative to the satellite array antenna of the satellite, including:

[0138] Based on the satellite coordinates, satellite attitude, and calibration terminal coordinates, a transformation relationship between the Earth coordinate system and the satellite body coordinate system is constructed.

[0139] Based on the transformation relationship, the coordinates of the calibration terminal are projected onto the satellite body coordinate system to determine the calculated angle value of the calibration terminal relative to the satellite array antenna of the satellite.

[0140] In this embodiment of the invention, the theoretical pointing of the antenna is calculated using a geometric model (such as coordinate system transformation and vector operation) based on the satellite's own orbital coordinates (position), attitude parameters (pitch / yaw / roll angles) and the known coordinates of the calibration terminal.

[0141] Optionally, a three-dimensional spatial reference system is constructed with the Earth's center as the origin, based on international standards (such as WGS-84). The latitude, longitude, and elevation data of the calibration terminal are acquired in real time via GNSS positioning and converted into three-dimensional coordinates in this coordinate system. With the satellite's center of mass as the origin, the satellite's attitude sensor measures the pitch, yaw, and roll angles in real time, and the onboard GNSS receiver provides the satellite's on-orbit spatial position coordinates. A three-dimensional rotation matrix is ​​generated based on the satellite's real-time attitude angles (pitch / yaw / roll), and combined with the satellite's orbital position vector, a transformation model between the Earth coordinate system and the satellite's body coordinate system is constructed.

[0142] The position vector of the calibration terminal in the Earth coordinate system is projected to the satellite body coordinate system through a transformation matrix to generate the local three-dimensional coordinates of the calibration terminal relative to the satellite's center of mass. The local coordinates of the calibration terminal are orthogonally projected onto the horizontal plane of the satellite array, and the angle between the projected vector and the array reference axis is calculated, outputting the theoretical azimuth component. The angle between the calibration terminal's position vector and the array normal direction is calculated, and combined with satellite roll attitude compensation, the theoretical pitch component is output.

[0143] Through the embodiments of the present invention, a transformation relationship between the Earth coordinate system and the satellite body coordinate system is constructed, and the coordinates of the calibration terminal are projected onto the satellite body coordinate system accordingly to determine the angle calculation value. This can accurately realize the transformation of position information under different coordinate systems and provide accurate angle basis for satellite beam pointing calibration.

[0144] According to the beam pointing calibration method for satellite communication provided by the present invention, the calibration terminal and the user terminal adopt the same communication protocol and signal modulation method, and the uplink reference signal is the uplink detection reference signal.

[0145] refer to Figure 3 , Figure 3 This is a schematic diagram of multi-beam satellite communication provided by the present invention. It includes: a satellite, a user terminal, a calibration terminal, and a uniform array.

[0146] In this embodiment of the invention, a broadband multi-beam LEO satellite based on orthogonal frequency division multiplexing is considered. The satellite is equipped with a UPA array, and each antenna element is a digital active antenna. The number of antennas on the x-axis and y-axis are respectively... and The total number of antennas is There are multiple user terminals within the satellite coverage area, and one or more calibration terminals with known locations are deployed simultaneously. The calibration terminal is also a type of user terminal, and its communication system is completely consistent with that of a normal user terminal. However, the calibration terminal does not transmit services; it is only used for measuring satellite beam pointing deviation. To improve the accuracy of beam pointing deviation measurement, the uplink transmission power of the calibration terminal can be appropriately increased.

[0147] The calibration terminal accesses the satellite network through uplink and downlink synchronization and periodically initiates uplink reference signals. The reference signals can be uplink sounding reference signals (SRS) in 5G or 5G NTN, or other uplink signals.

[0148] Through the embodiments of the present invention, there is no need to design a dedicated ground calibration station and calibration signal. Beam pointing deviation measurement is achieved solely using the communication signal between the ground terminal and the base station, significantly reducing system complexity. Beam pointing calibration utilizes only the uplink signal of the calibration terminal, and the measurement and calibration process has no impact on terminal communication between the system and other terminals.

[0149] According to the beam pointing calibration method for satellite communication provided by the present invention, the number of calibration terminals is multiple, and the method further includes:

[0150] The beam pointing deviation between each of the multiple calibration terminals and the satellite is determined to obtain the beam pointing deviation set;

[0151] The target measurement value is obtained by weighted summation based on the beam pointing deviation set;

[0152] The satellite's beam pointing is calibrated based on the target measurement values.

[0153] In this embodiment of the invention, multiple calibration terminals are deployed at key ground locations (different azimuth and elevation angles within the satellite coverage area) to form a monitoring network covering the satellite beam scanning range. The calibration terminals adopt the same communication system as ordinary user terminals and dynamically increase the transmission power of edge terminals according to the satellite orbit position to ensure balanced signal quality across the entire area.

[0154] The satellite uses a time-division scheduling system to sequentially cover each terminal, independently performing direction-of-arrival (DOA) estimation and theoretical angle calculation for each terminal. This generates a beam pointing deviation set containing azimuth / elevation bias components, while simultaneously filtering out low signal-to-noise ratio data in real time to ensure measurement reliability. The target measurement value is obtained by weighted summation based on the beam pointing deviation set.

[0155] Through the embodiments of the present invention, multiple calibration terminals are used for measurement. Each calibration terminal is located in a different environment and position, and its measurement results include different aspects of beam pointing characteristics, thus avoiding the one-sidedness and limitations that may be caused by measurement with a single calibration terminal.

[0156] Furthermore, in multi-satellite networking scenarios, when each satellite passes the calibration terminal, the uplink signal from the calibration terminal is used to measure and calibrate the beam pointing of that satellite. When multiple satellites simultaneously cover the calibration terminal, the uplink signal from the same calibration terminal can be used for beam pointing measurement and calibration of each satellite. This method utilizes the DOA estimation of the calibration terminal's uplink signal for beam pointing deviation measurement and calibration, and is equally suitable in multi-satellite scenarios.

[0157] The beam pointing calibration device for satellite communication provided by the present invention will be described below. The beam pointing calibration device for satellite communication described below can be referred to in correspondence with the beam pointing calibration method for satellite communication described above.

[0158] refer to Figure 4 , Figure 4 This is a schematic diagram of the beam pointing calibration device for satellite communication provided by the present invention.

[0159] The signal acquisition module 401 is used to acquire the uplink reference signal sent by the calibration terminal, wherein the calibration terminal is deployed at a known location on the ground;

[0160] Angle estimation module 402 is used to perform direction of arrival estimation based on uplink reference signal to obtain the angle estimate of the calibration terminal relative to the satellite array antenna.

[0161] Angle calculation module 403 is used to determine the angle calculation value of the calibration terminal relative to the satellite array antenna of the satellite based on the satellite coordinates, the satellite attitude of the satellite and the calibration terminal coordinates of the calibration terminal.

[0162] The difference determination module 404 is used to take the difference between the estimated angle value and the calculated angle value as the measured value of the beam pointing deviation;

[0163] The calibration module 405 is also used to calibrate the beam pointing of the satellite based on the measured value of the beam pointing deviation.

[0164] The following describes another embodiment of the beam pointing calibration device for satellite communication provided by the present invention.

[0165] refer to Figure 5 , Figure 5 This is a schematic flowchart of the beam pointing calibration device for satellite communication provided by the present invention. The beam pointing calibration device includes: an angle estimation module for the calibration terminal (inputs are antenna received signal, system configuration information, and calibration terminal reference signal configuration information), an angle calculation module for the calibration terminal (inputs are satellite coordinates, satellite attitude, and calibration terminal coordinates), and a beam pointing deviation calculation module (outputs the beam pointing deviation measurement value to the attitude and orbit control module or the beam control module).

[0166] Specifically, the beam pointing calibration device for satellite communication provided by the present invention can realize all the method steps implemented in the above-mentioned satellite communication beam pointing calibration method embodiment, and can achieve the same technical effect. Here, the parts that are the same as those in the method embodiment and the beneficial effects will not be described in detail.

[0167] Figure 6 This is a schematic diagram of the physical structure of the electronic device provided by the present invention, such as... Figure 6 As shown, the electronic device may include a processor 610, a communications interface 620, a memory 630, and a communication bus 640, wherein the processor 610, communications interface 620, and memory 630 communicate with each other via the communication bus 640. The processor 610 can call logical instructions in the memory 630 to execute a beam pointing calibration method for satellite communication. This method includes: acquiring an uplink reference signal transmitted by a calibration terminal, wherein the calibration terminal is deployed at a known location on the ground; performing direction of arrival estimation based on the uplink reference signal to obtain an estimated angle value of the calibration terminal relative to the satellite array antenna; determining a calculated angle value of the calibration terminal relative to the satellite array antenna based on the satellite coordinates, the satellite attitude, and the calibration terminal coordinates; using the difference between the estimated angle value and the calculated angle value as a measured value of beam pointing deviation; and calibrating the satellite beam pointing based on the measured value of beam pointing deviation.

[0168] Furthermore, the logical instructions in the aforementioned memory 630 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0169] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the beam pointing calibration method for satellite communication provided by the above methods. The method includes: acquiring an uplink reference signal transmitted by a calibration terminal, wherein the calibration terminal is deployed at a known location on the ground; performing direction of arrival estimation based on the uplink reference signal to obtain an estimated angle value of the calibration terminal relative to the satellite array antenna; determining a calculated angle value of the calibration terminal relative to the satellite array antenna based on the satellite coordinates, the satellite attitude, and the calibration terminal coordinates; using the difference between the estimated angle value and the calculated angle value as a measured value of beam pointing deviation; and calibrating the beam pointing of the satellite based on the measured value of beam pointing deviation.

[0170] In another aspect, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements a beam pointing calibration method for satellite communication provided by the methods described above. This method includes: acquiring an uplink reference signal transmitted by a calibration terminal, wherein the calibration terminal is deployed at a known location on the ground; performing direction-of-arrival estimation based on the uplink reference signal to obtain an estimated angle of the calibration terminal relative to a satellite array antenna; determining a calculated angle of the calibration terminal relative to the satellite array antenna based on the satellite coordinates, the satellite attitude, and the calibration terminal coordinates; using the difference between the estimated angle and the calculated angle as a measured beam pointing deviation; and calibrating the beam pointing of the satellite based on the measured beam pointing deviation.

[0171] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0172] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0173] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A beam pointing calibration method for satellite communication, characterized in that, Applied to a satellite, the satellite is equipped with a satellite array antenna, including: Acquire the uplink reference signal sent by the calibration terminal, wherein the calibration terminal is deployed at a known location on the ground; Based on the uplink reference signal, direction of arrival estimation is performed to obtain the angle estimate of the calibration terminal relative to the satellite array antenna; Based on the satellite coordinates, the satellite attitude, and the calibration terminal coordinates, the angle calculation value of the calibration terminal relative to the satellite array antenna of the satellite is determined. The difference between the estimated angle and the calculated angle is used as the measured value of the beam pointing deviation. The beam pointing of the satellite is calibrated based on the measured value of the beam pointing deviation. The calibration terminal and the user terminal use the same communication protocol and signal modulation method, and the uplink reference signal is an uplink detection reference signal.

2. The beam pointing calibration method for satellite communication according to claim 1, characterized in that, The step of estimating the direction of arrival (DOA) based on the uplink reference signal to obtain an estimated angle of the calibration terminal relative to the satellite array antenna includes: Channel estimation is performed using the uplink reference signals of each channel of the satellite array antenna to obtain a channel estimation vector, which includes the array response vector of the calibration terminal. Construct a spatial sampling matrix, wherein the dimension of the spatial sampling vector in the spatial sampling matrix is ​​the same as the dimension of the channel estimation vector, and the spatial sampling vector is an array response vector at different spatial angles; The correlation value between each spatial sampling vector in the spatial sampling matrix and the channel estimation vector is calculated, and the index of the target sampling vector corresponding to the largest correlation value is determined. Spatial angle mapping is performed based on the target sampling vector index to obtain the angle estimate of the calibration terminal relative to the satellite array antenna.

3. The beam pointing calibration method for satellite communication according to claim 1, characterized in that, The calibration of the satellite's beam pointing based on the measured beam pointing deviation includes one of the following: The weights of the satellite's beamforming vector are corrected based on the measured beam pointing deviation. The satellite attitude is corrected based on the measured value of the beam pointing deviation.

4. The beam pointing calibration method for satellite communication according to claim 1, characterized in that, The step of determining the angle calculation value of the calibration terminal relative to the satellite array antenna of the satellite based on the satellite coordinates, the satellite attitude of the satellite, and the calibration terminal coordinates of the calibration terminal includes: Based on the satellite coordinates, the satellite attitude, and the calibration terminal coordinates, a transformation relationship between the Earth coordinate system and the satellite body coordinate system is constructed. Based on the transformation relationship, the coordinates of the calibration terminal are projected onto the satellite body coordinate system to determine the calculated angle value of the calibration terminal relative to the satellite array antenna of the satellite.

5. The beam pointing calibration method for satellite communication according to claim 1, characterized in that, The step of estimating the direction of arrival (DOA) based on the uplink reference signal to obtain an estimated angle of the calibration terminal relative to the satellite array antenna includes: The uplink reference signal is preprocessed to obtain the preprocessed array signal; The preprocessed array signal is segmented by time, and the spatial covariance matrix is ​​calculated for each segment. Based on the spatial covariance matrix, a high-resolution direction-of-arrival estimation algorithm is used to calculate the angle, thereby obtaining the estimated angle value of the satellite array antenna. The high-resolution direction-of-arrival estimation algorithm includes at least one of the following: subspace algorithm, maximum likelihood algorithm, and beamforming algorithm.

6. The beam pointing calibration method for satellite communication according to claim 1, characterized in that, The number of calibration terminals is multiple, and the method further includes: The measured value of the beam pointing deviation between each of the multiple calibration terminals and the satellite is determined to obtain a beam pointing deviation set; The target measurement value is obtained by weighted summation based on the beam pointing deviation set. The beam pointing of the satellite is calibrated based on the target measurement values.

7. A beam pointing calibration device for satellite communication, characterized in that, include: A signal acquisition module is used to acquire the uplink reference signal sent by the calibration terminal, wherein the calibration terminal is deployed at a known location on the ground; An angle estimation module is used to perform direction of arrival estimation based on the uplink reference signal to obtain the angle estimate of the calibration terminal relative to the satellite array antenna. An angle calculation module is used to determine the angle calculation value of the calibration terminal relative to the satellite array antenna of the satellite based on the satellite coordinates, the satellite attitude of the satellite, and the calibration terminal coordinates of the calibration terminal. The difference determination module is used to take the difference between the estimated angle value and the calculated angle value as the measured value of the beam pointing deviation; The calibration module is also used to calibrate the beam pointing of the satellite based on the measured value of the beam pointing deviation; The calibration terminal and the user terminal use the same communication protocol and signal modulation method, and the uplink reference signal is an uplink detection reference signal.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the beam pointing calibration method for satellite communication as described in any one of claims 1 to 6.

9. A non-transitory 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 beam pointing calibration method for satellite communication as described in 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 beam pointing calibration method for satellite communication as described in any one of claims 1 to 6.

Images