A method and system for jointly suppressing epfd of geo adjacent satellites by geo satellite

Abstract

The application discloses a polar orbit satellite GEO adjacent satellite EPFD joint suppression method and system, and relates to the technical field of satellite communication interference suppression. The method comprises the following steps: according to the real-time ephemeris solution of the 97-degree inclination orbit of the polar orbit satellite and the spatial isolation angle of the GEO adjacent satellite, when the spatial isolation angle is smaller than the isolation angle threshold, on the basis of Taylor weighting, the beam null compensation phase is adaptively calculated in the direction of the adjacent satellite and is superimposed to the weight value, and a synthesized directivity pattern is generated; according to the coupling relationship between the residual sidelobe level of the adjacent satellite direction in the synthesized directivity pattern and the isolation angle, the Ku link power backoff amount is determined, the transmission power is dynamically backed off, and the synthesized directivity pattern is jointly injected into the downlink; meanwhile, the above parameters are compared with the ITU EPFD limit value in a closed loop, and when the isolation angle crosses the threshold, the null phase and the backoff amount are synchronously updated. The application effectively suppresses the EPFD interference of the polar orbit satellite on the GEO adjacent satellite, and guarantees the data transmission rate and compliance.

Description

Technical Field

[0001] This invention relates to the field of satellite communication interference suppression technology, and in particular to a method and system for joint suppression of EPFD between polar-orbiting satellites and GEO neighboring satellites. Background Technology

[0002] The polar-orbiting satellite operates in a 97° inclination sun-synchronous orbit at an altitude of approximately 500 km, with a period of 94.5 minutes. Due to the Earth's rotation, the longitude of its nadir shifts westward by approximately 23.6° per orbit. GEO communication satellites are deployed at orbital positions 120°E and 124°E, sharing the Ku-band frequency with the polar-orbiting satellite. When the longitude of the polar-orbiting satellite's nadir approaches that of the GEO orbital position, its antenna sidelobes may point towards the neighboring GEO satellite, posing an interference risk.

[0003] Traditional fixed-weighted antennas use Taylor or Chebyshev weighting to achieve low sidelobes, but they cannot dynamically nullify them for specific interference directions. During full-latitude sweeping of GEO orbits by polar-orbiting satellites, sidelobes continuously illuminate neighboring satellites, making it difficult to meet the EPFD limits specified in Article 22 of the ITU Radio Regulations. Existing adaptive beamforming technologies have high computational complexity and do not consider the joint optimization of polar-orbiting orbital motion characteristics and power backoff.

[0004] In existing technologies, the fixed power back-off scheme fails to utilize the spatial suppression potential of the antenna pattern, leading to unnecessary communication capacity loss. While the pure adaptive beam nulling scheme can form nulls in specific directions, it is limited by the rapid changes in the direction of arrival caused by the high-speed motion of polar-orbiting satellites, resulting in lag in null direction tracking and causing transient exceedances in EPFD. Furthermore, existing adaptive beamforming algorithms replace fixed weighting with fully adaptive weights, disrupting the low sidelobe envelope characteristics of Taylor weighting or Chebyshev weighting and introducing gain fluctuations in the main lobe region. None of the above technical solutions establish a coupling relationship between antenna spatial characteristics and transmit power time-domain control, making it impossible to achieve joint optimization of EPFD compliance and communication performance. Summary of the Invention

[0005] This invention proposes a joint suppression method for EPFD of GEO neighboring satellites by polar-orbiting satellites, comprising: S1. Based on the real-time ephemeris of the polar-orbiting satellite's 97° inclination orbit, calculate the spatial isolation angle between the polar-orbiting satellite and its neighboring GEO satellites at 120°E and 124°E, and compare this spatial isolation angle with a preset isolation angle threshold in real time. S2. When the spatial isolation angle is less than the isolation angle threshold, based on the Taylor weighting weight of the phased array antenna, calculate the beam null compensation phase value in the direction of the GEO neighboring star at 120°E or 124°E according to the spatial isolation angle, superimpose the beam null compensation phase value onto the Taylor weighting weight to generate the composite weighting weight, and calculate the composite pattern based on the composite weighting weight. S3. Based on the composite pattern after superimposing the beam null compensation phase values, calculate the residual sidelobe level values ​​in the 120°E and 124°E GEO neighbor directions, and determine the power back-off amount of the Ku-band transmit link for polar-orbiting satellites based on the coupling mapping relationship between the residual sidelobe level values ​​and the spatial isolation angle. S4. Based on the power back-off amount, the Ku-band transmit power is dynamically backed off, and the backed-off transmit power and the composite radiation pattern are injected into the downlink together, so that the equivalent isotropic radiation power of the polar-orbiting satellite to the GEO neighboring satellite is reduced synchronously. S5. Perform a closed-loop comparison of the spatial isolation angle, residual sidelobe level, and power back-off with the ITU EPFD limit. When the spatial isolation angle crosses the isolation angle threshold, synchronously update the beam null compensation phase value and power back-off.

[0006] The above-described method for joint suppression of EPFD by a polar-orbiting satellite and its GEO neighbor satellites includes the following sub-steps: Based on the real-time ephemeris of the polar-orbiting satellite's 97° inclination orbit, the spatial isolation angle between the polar-orbiting satellite and the orbits of its 120°E and 124°E GEO neighbor satellites is calculated, and this spatial isolation angle is compared in real-time with a preset isolation angle threshold. Based on the real-time position and velocity information output by the onboard GNSS receiver of the polar-orbiting satellite, and combined with the orbital elements at a 97° inclination angle of the polar-orbiting satellite, the instantaneous orbital parameters of the polar-orbiting satellite are calculated, and real-time ephemeris data of the satellite is generated. Based on real-time satellite ephemeris data, the spatial vector from the phase center of the polar-orbiting satellite antenna to the GEO neighboring satellite orbit positions at 120°E and 124°E is determined, and the spatial isolation angle is calculated based on the angle between this spatial vector and the polar-orbiting satellite's Earth pointing vector. The calculated spatial isolation angle is compared with the preset isolation angle threshold, and it is determined in real time whether the spatial isolation angle is less than the isolation angle threshold, and an isolation angle status indicator is generated.

[0007] The above-described method for joint suppression of EPFD by a polar-orbiting satellite against a GEO neighbor satellite includes the following sub-steps: When the spatial isolation angle is less than the isolation angle threshold, based on the Taylor weighting values ​​of the phased array antenna, a beam null compensation phase value is calculated in the direction of the 120°E or 124°EGEO neighbor satellite according to the spatial isolation angle. This beam null compensation phase value is then superimposed on the Taylor weighting values ​​to generate a composite weighting value. A composite radiation pattern is then calculated based on this composite weighting value. The spatial steering vector of the GEO neighbor is determined based on the incoming wave direction angle of the GEO neighbor relative to the normal direction of the phased array antenna of the polar-orbiting satellite at 120°E or 124°E. Based on the spatial steering vector, the beam null compensation phase value in the direction of the GEO neighboring star at 120°E or 124°E is calculated using the minimum variance distortionless response criterion. The beam null compensation phase value is then superimposed on the Taylor weighted weight of each array element in a complex multiplication-addition manner to generate a composite weighted weight. Based on the combined weighting values ​​of each array element, a composite radiation pattern of the phased array antenna is formed. This composite radiation pattern forms an adaptive null in the 120°E and 124°E GEO neighboring satellite directions, while maintaining the main lobe gain of the ground data transmission beam.

[0008] The above-described method for joint EPFD suppression of a polar-orbiting satellite against a GEO neighbor satellite includes the following sub-steps: Based on the composite pattern obtained by superimposing beam null compensation phase values, the residual sidelobe levels at 120°E and 124°E along the GEO neighbor direction are calculated. Then, based on the coupling mapping relationship between these residual sidelobe levels and the spatial isolation angle, the power back-off amount of the polar-orbiting satellite's Ku-band transmit link is determined. Based on the pattern function of the composite pattern, the pattern amplitude response values ​​in the direction of incoming waves from the GEO neighboring star at 120°E and 124°E are extracted, and these amplitude response values ​​are used as the residual sidelobe level values. Based on the deviation between the spatial isolation angle and the preset isolation angle threshold, and combined with the residual sidelobe level, the margin of the actual equivalent isotropic radiated power of the polar-orbiting satellite in the direction of the GEO neighboring satellite is determined relative to the limit. Based on the correspondence between margin, power back-off, and spatial isolation angle, the power back-off amount of the Ku-band transmit link is determined.

[0009] The above-described method for joint suppression of EPFD by a polar-orbiting satellite on a GEO neighbor satellite includes the following sub-steps: Based on the power backoff amount, the Ku-band transmit power is dynamically backed up, and the backed-up transmit power is injected into the downlink along with the composite radiation pattern, thereby synchronously reducing the equivalent isotropic radiated power of the polar-orbiting satellite on the GEO neighbor satellite. Based on the power back-off amount, a transmit power control command is generated, and the output power of the power amplifier is adjusted to the target power value after back-off through the gate voltage adjustment port of the solid-state power amplifier in the Ku-band transmit link. The backed-up transmit power and the spatial gain distribution of the composite pattern are combined and calculated to obtain the actual equivalent isotropic radiation power of the polar-orbiting satellite toward the GEO neighboring satellite, so that the actual equivalent isotropic radiation power meets the ITU EPFD limit requirements. The radio frequency signal corresponding to the back-off transmit power is fed into each element of the phased array antenna after being shaped by the synthesized radiation pattern, and then radiated out through the downlink.

[0010] The above-described method for joint suppression of EPFD by a polar-orbiting satellite and a GEO neighboring satellite involves a closed-loop comparison of the spatial isolation angle, residual sidelobe level, power back-off, and ITU EPFD limits. When the spatial isolation angle crosses the isolation angle threshold, the beam null compensation phase value and power back-off are updated synchronously. This method includes the following sub-steps: Compare the spatial isolation angle at the current moment with the spatial isolation angle at the previous moment, and determine whether the spatial isolation angle has changed from being greater than the isolation angle threshold to being less than the isolation angle threshold, or from being less than the isolation angle threshold to being greater than the isolation angle threshold. If a crossover occurs, the synchronization update flag is triggered. When the synchronization update flag is triggered, the beam null compensation phase value in the direction of the GEO neighboring star is recalculated based on the spatial isolation angle at the current moment after the crossing, and the power backoff amount is updated based on the re-extracted residual sidelobe level value. The updated beam null compensation phase value is re-superimposed onto the Taylor weighting value to generate an updated composite weighting value, and the updated power back-off amount is fed into the transmit power control link so that the beam null depth and transmit power are adjusted synchronously with the change of spatial isolation angle.

[0011] The above-described method for joint suppression of EPFD by a polar-orbiting satellite against a GEO neighbor satellite includes the following sub-steps: Based on the space steering vector, the beam null compensation phase value in the direction of the GEO neighbor satellite at 120°E or 124°E is calculated using the minimum variance distortion-free response criterion. This beam null compensation phase value is then superimposed onto the Taylor weighted weights of each array element using a complex multiplication-addition method to generate a composite weighted value. Based on the geometric characteristics of the full latitude sweeping GEO orbit of the polar-orbiting satellite at an inclination of 97°, the spatial phase difference between the 120°E and 124°E GEO neighboring satellites and the phased array antenna surface of the polar-orbiting satellite is dynamically updated, and this spatial phase difference is introduced into the beamformer as a null constraint condition. Under the Taylor-weighted low sidelobe constraint, a linear constraint minimum variance optimization problem is constructed based on the null constraint condition. Solving this optimization problem yields the beam null compensation phase value for each array element. The solved beam null compensation phase value is superimposed with the Taylor weighted value of the corresponding array element by complex multiplication to generate a composite weighted value, so that the composite pattern forms an adaptive null in the direction of the GEO neighbor while maintaining low sidelobe characteristics.

[0012] This invention also proposes a joint suppression system for polar-orbiting satellites against GEO neighboring satellites' EPFD, comprising: The orbit calculation module calculates the spatial isolation angle between the polar-orbiting satellite and its neighboring satellites at 120°E and 124°E GEO positions based on the real-time ephemeris of the 97° inclination orbit of the polar-orbiting satellite, and compares the spatial isolation angle with the preset isolation angle threshold in real time. Beam nulling module: When the spatial isolation angle is less than the isolation angle threshold, the beam nulling compensation phase value in the direction of the GEO neighboring star at 120°E or 124°E is calculated based on the Taylor weighting weight of the phased array antenna. This beam nulling compensation phase value is then superimposed on the Taylor weighting weight to generate a composite weighting weight, and the composite radiation pattern is calculated based on this composite weighting weight. Power back-off module: Based on the composite pattern after superimposing the beam null compensation phase values, calculate the residual sidelobe level values ​​in the 120°E and 124°EGEO neighboring satellite directions, and determine the power back-off amount of the Ku-band transmit link of the polar-orbiting satellite according to the coupling mapping relationship between the residual sidelobe level value and the spatial isolation angle. Link power control and injection module: Based on the power back-off amount, the Ku-band transmit power is dynamically backed off, and the backed-off transmit power and the composite radiation pattern are injected into the downlink together, so that the equivalent isotropic radiation power of the polar-orbiting satellite to the GEO neighboring satellite is reduced synchronously. Closed-loop update module: The spatial isolation angle, residual sidelobe level, and power back-off are compared with the ITU EPFD limit in a closed loop. When the spatial isolation angle crosses the isolation angle threshold, the beam null compensation phase value and power back-off are updated synchronously.

[0013] The beneficial effects achieved by this invention are as follows: This invention incorporates the geometric characteristics of a polar-orbiting satellite's 97° inclination full-latitude sweep of the GEO orbit into beam nulling calculations, achieving real-time adaptive adjustment of the nulling direction according to the satellite's orbital position. This effectively solves the technical problem of continuous sidelobe interference with GEO neighboring satellites during polar-orbiting flight using traditional fixed-weighted antennas. Simultaneously, this invention constructs a triple-linked suppression mechanism of "low-sidelobe array weighting + spatial adaptive nulling + dynamic transmit power backoff." Based on the formation of a deep null in the direction of the GEO neighboring satellite, the power backoff amount is dynamically adjusted according to the coupling mapping relationship between the residual sidelobe level and the spatial isolation angle. This invention can maximize the transmission rate and signal quality of the polar-orbiting satellite-to-ground data transmission link while meeting ITU EPFD limits, achieving dual optimization of spectrum compatibility and communication efficiency. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0015] Figure 1 This is a flowchart of a method for joint suppression of EPFD by a polar-orbiting satellite and a GEO neighboring satellite provided in an embodiment of this application.

[0016] Figure 2 This is a schematic diagram of a polar-orbiting satellite-GEO neighboring satellite EPFD joint suppression system provided in an embodiment of this application. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Example 1 like Figure 1 As shown in the embodiment of this application, a method for joint suppression of EPFD by a polar-orbiting satellite on a GEO neighboring satellite includes: Step S1: Based on the real-time ephemeris of the polar-orbiting satellite's 97° inclination orbit, calculate the spatial isolation angle between the polar-orbiting satellite and its neighboring GEO satellites at 120°E and 124°E, and compare this spatial isolation angle with a preset isolation angle threshold in real time. Specifically, using the real-time position and velocity information output by the onboard GNSS receiver of the polar-orbiting satellite, and combining it with the orbital elements at a 97° inclination angle, instantaneous orbital parameters are calculated to generate real-time satellite ephemeris data. Based on this ephemeris data, the spatial vector from the antenna phase center to the 120°E and 124°E GEO neighboring satellite orbit positions is determined, and the spatial isolation angle is calculated in conjunction with the satellite's Earth pointing vector. The calculated isolation angle is compared with a preset threshold in real time, and an isolation angle status indicator is output. This process includes the following sub-steps: Step S11: Based on the real-time position and velocity information output by the onboard GNSS receiver of the polar-orbiting satellite, and combined with the 97° inclination orbital elements of the polar-orbiting satellite, calculate the instantaneous orbital parameters of the polar-orbiting satellite and generate real-time ephemeris data of the satellite. During the operation of a polar-orbiting satellite, the onboard GNSS receiver continuously outputs the satellite's three-dimensional position and velocity vectors in the geocentric coordinate system. The raw observations output by the GNSS receiver are filtered to obtain the position and velocity vectors.

[0019] Based on this, and taking into account the orbital elements constraints of a 97° inclination orbit—orbital inclination of 97°, orbital eccentricity, right ascension of the ascending node, argument of perigee, and mean perigee—the filtered position and velocity data undergoes consistency verification to eliminate outliers caused by brief GNSS lockouts or ephemeris jumps. The verified position and velocity data is then encapsulated into real-time ephemeris data packets.

[0020] Step S12: Based on the real-time ephemeris data of the satellite, determine the spatial vector from the phase center of the polar-orbiting satellite antenna to the orbital positions of neighboring satellites at 120°E and 124°EGEO, and calculate the spatial isolation angle based on the angle between the spatial vector and the polar-orbiting satellite's Earth pointing vector. Both the 120°E and 124°E GEO Proxima Neighbors are located in geosynchronous orbit, with longitudes of 120°E and 124°E respectively, and orbital altitudes of approximately 35,786 km. Based on the longitudes of the GEO satellites' orbits, their position vectors in the geocentric-ground-fixed coordinate system are calculated. Taking the 120°E GEO Proxima Neighbor as an example, its position vector is determined by its equatorial radius, orbital longitude, and GEO orbital altitude. The spatial vector from the phase center of the polar-orbiting satellite antenna to the GEO Proxima Neighbor is obtained by subtracting the position vector of the polar-orbiting satellite antenna phase center from the position vector of the GEO Proxima Neighbor. The position vector of the polar-orbiting satellite antenna phase center is obtained by transforming the antenna installation offset in the satellite's body coordinate system to the geocentric-ground-fixed coordinate system using an attitude rotation matrix and then superimposing it with the position vector.

[0021] Determining the Earth pointing vector of a polar-orbiting satellite requires the introduction of satellite attitude information. The onboard attitude determination system outputs the roll, pitch, and yaw angles of the satellite relative to the orbital coordinate system in real time. The filtered position vector is normalized and then reversed to obtain the nominal Earth pointing direction. After attitude angle correction, the actual Earth pointing vector is obtained. The spatial isolation angle is defined as the angle between the spatial vector and the actual Earth pointing vector, and is expressed by the following formula: ,in, This indicates that the actual Earth-pointing beam direction of the polar-orbiting satellite is related to the first... The sharp angle between the directions of the GEO neighboring star and the target star is used to trigger the interference avoidance process when the value is less than the preset threshold of 12°. This represents the radian conversion factor, a fixed constant of 57.29578, used to convert the radian output of the inverse cosine function into degrees, a value commonly used in engineering. The inverse cosine function is used to convert the cosine ratio calculated from the numerator and denominator back into the corresponding radian angle. Indicates the GEO neighbor number, when The time represents the neighboring star at orbital position 120°E, when The time represents the neighboring star at orbital position 124°E; Represents the ECEF position vector of the GEO satellite; Indicates the real-time position of the antenna phase center ECEF; This represents the transpose operator; This represents the attitude rotation matrix from the body to the ECEF, used to rotate the star vector to the Earth-fixed coordinate system; Indicates the real-time position of the satellite's center of mass (ECEF); This represents the Euclidean norm of a vector.

[0022] Step S13: Compare the calculated spatial isolation angle with the preset isolation angle threshold, determine in real time whether the spatial isolation angle is less than the isolation angle threshold, and generate an isolation angle status indicator; The preset isolation angle threshold is pre-calibrated based on ITU EPFD limits and the sidelobe envelope characteristics of polar-orbiting satellite phased array antennas. The isolation angle status identifier is defined as a binary variable.

[0023] Step S2: When the spatial isolation angle is less than the isolation angle threshold, based on the Taylor weighted weight of the phased array antenna, calculate the beam null compensation phase value in the direction of the GEO neighboring star at 120°E or 124°E according to the spatial isolation angle, superimpose the beam null compensation phase value onto the Taylor weighted weight to generate the composite weighted weight, and calculate the composite pattern based on the composite weighted weight. Specifically, the spatial steering vector is determined based on the incoming wave direction angle of the 120°E or 124°E GEO neighboring satellite relative to the normal direction of the polar-orbiting satellite phased array antenna. The beam null compensation phase value in this direction is calculated based on the minimum variance distortion-free response criterion and then superimposed onto the Taylor weighted weights of each array element using a complex multiplication-addition method to generate a composite weighted weight. Furthermore, based on the geometric characteristics of the polar-orbiting satellite's 97° inclination orbit sweeping the GEO orbit across all latitudes, the spatial phase difference between the neighboring satellite and the antenna array is dynamically updated and introduced into the beamformer as a null constraint. A linear constraint minimum variance optimization problem is constructed under Taylor weighted low sidelobe constraints. The compensation phase value of each array element is solved and then multiplied and superimposed with the corresponding Taylor weight to form a composite radiation pattern. This pattern creates an adaptive null in the direction of the neighboring satellite while maintaining the main lobe gain of the ground data transmission beam. The specific steps include the following: Step S21: Determine the spatial steering vector of the GEO neighboring satellite based on the incoming wave direction angle of the GEO neighboring satellite relative to the normal direction of the polar-orbiting satellite phased array antenna at 120°E or 124°E. The phased array antenna is mounted on the ground-pointing panel of the polar-orbiting satellite, and its array surface normal direction is consistent with the satellite's actual ground-pointing vector. The spatial vector is transformed from the geocentric coordinate system to the antenna body coordinate system, resulting in the spatial vector in the antenna body coordinate system. The direction of arrival (AOI) is determined by the azimuth and elevation angles of this spatial vector in the antenna body coordinate system. For a uniform rectangular phased array composed of multiple elements, with each element equally spaced and the reference element located at the array origin, each element of the spatial steering vector in the GEO neighbor direction is determined by the spatial phase difference between each element and the reference element. This phase difference depends on the element position, the AOI, and the operating wavelength.

[0024] Step S22: Based on the space steering vector, calculate the beam null compensation phase value in the direction of the 120°E or 124°EGEO neighboring star using the minimum variance distortionless response criterion, and then superimpose the beam null compensation phase value onto the Taylor weighted weight of each array element in a complex multiplication-addition manner to generate the composite weighted weight. Step S221: Based on the geometric characteristics of the full latitude sweep of the GEO orbit by the polar-orbiting satellite at an inclination of 97°, dynamically update the spatial phase difference between the GEO neighboring satellites at 120°E and 124°E and the phased array antenna surface of the polar-orbiting satellite, and introduce this spatial phase difference as a null constraint condition into the beamformer. A 97° inclination orbit allows the polar-orbiting satellite to traverse almost all geographical latitudes within each orbital period, resulting in drastic changes in the spatial geometry of the GEO neighbor relative to the polar-orbiting satellite's antenna array. When the polar-orbiting satellite flies near the equator, the GEO neighbor is located to the side of the antenna array, with a significant spatial phase difference; conversely, as the polar-orbiting satellite flies higher latitudes, the GEO neighbor gradually moves behind the antenna array, and the spatial phase difference approaches zero. Based on the spatial vector calculated in real-time in the antenna body coordinate system, the phase difference of the received signal of each array element relative to the reference array element in the direction of the GEO neighbor is calculated, forming a constraint steering vector. This constraint steering vector is updated in real-time with the satellite's orbital position, ensuring that the null direction is always aligned with the instantaneous spatial position of the GEO neighbor.

[0025] Step S222: Under the Taylor weighted low sidelobe constraint, construct a linear constraint minimum variance optimization problem based on the null constraint condition, and solve the optimization problem to obtain the beam null compensation phase value of each array element. While ensuring distortion-free transmission of data transmission signals to Earth and maintaining the main lobe gain, the radiated power of the array in the direction of the GEO neighboring satellite is reduced, thereby creating a null in the interference direction. Let the synthesized weighted vector be the unknown quantity. The main lobe direction steering vector and the constraint steering vector together constitute the constraint matrix. The desired response value is determined by both the main lobe direction requirement and the null depth requirement.

[0026] The composite weighted vector is represented by the following formula: in, This represents the composite weighted vector; the amplitude and phase of each complex number determine the power and phase delay of the transmitted signal of the corresponding array element, respectively. The Taylor weighted reference vector is obtained offline from the ground using the Taylor synthesis method. It serves as the optimization reference for this formula and provides a low sidelobe amplitude distribution template for the synthesized weights. express The inverse matrix is ​​obtained by calling the matrix inverse function of the onboard DSP. The result is obtained in real time; it is used to project the constraint guidance vector from the element space to the whitened feature space, so that the correction amount automatically reduces the adjustment range in the direction where noise and interference energy are concentrated. This represents the constraint guidance vector matrix, with the first column being the guidance vector for the main lobe direction. (Geostationary data transmission direction), the second column is the GEO neighboring satellite direction constraint steering vector. (Obtained by substituting the direction angle of arrival from the real-time ephemeris calculation in step S12), used to simultaneously apply the two constraints of main lobe conformity and null trap, and is the basis for the generation of the correction term; express The conjugate transpose matrix, obtained by the onboard DSP The matrix is ​​obtained by taking the conjugate of each element and then transposing it. This matrix is ​​used to project the composite weights and Taylor weights to be determined from the 256-dimensional weight space to the 2-dimensional constraint space, so as to calculate the deviation between the actual response value and the expected value of the current weight in the two constraint directions. This represents the desired response vector, which is directly given by the design specifications. 1 indicates that a distortion-free response must be maintained in the main lobe direction, and 0 indicates that a null trap must be forced in the GEO neighbor direction. It is used to subtract the actual response from the Taylor weights in the two constraint directions.

[0027] Noise covariance matrix This characterizes the thermal noise statistical characteristics of each element's receiving channel in a phased array antenna. The main diagonal elements represent the noise power of each channel, while the off-diagonal elements represent the cross-correlation between channels. In spaceborne transmission mode... The matrix is ​​determined as follows: During the ground testing phase, based on the noise figure, operating bandwidth, and system temperature of each receiving channel of the phased array antenna, the equivalent noise temperature of each channel is calculated, and a diagonalized noise covariance matrix is ​​constructed; during on-orbit operation, the onboard DSP calls pre-stored... The matrix serves as the whitening filter reference for the beamformer. This matrix remains constant throughout the mission cycle and is only updated by ground commands when the channel characteristics drift beyond a preset tolerance. The matrix inversion function is called by the onboard DSP. The result is obtained in real time and is used to project the constraint guidance vector from the element space to the whitened feature space, so that the correction amount automatically reduces the adjustment range in the direction where noise and interference energy are concentrated.

[0028] The composite weighted vector obtained by solving the inverse of the constraint matrix is ​​the amplitude phase compensation coefficient of each array element, and its phase component is the required null compensation phase. Since the constraint steering vector is updated in real time with the orbit position, the beam null compensation phase value calculated each time corresponds precisely to the spatial isolation angle at the current moment.

[0029] Step S223: The solved beam null compensation phase value is superimposed with the Taylor weighted weight of the corresponding array element by complex multiplication to generate a composite weighted weight, so that the composite pattern forms an adaptive null in the direction of the GEO neighbor star while maintaining low sidelobe characteristics. Since the synthesized weighting vector is expressed in complex form as weighting coefficients, its real and imaginary parts correspond to amplitude modulation and phase modulation components, respectively. After multiplying it by the complex Taylor weighting value, the synthesized weighting value retains the low sidelobe amplitude distribution characteristics of Taylor weighting while introducing null phase compensation for the direction of GEO neighboring stars.

[0030] Step S23: Based on the composite weighting values ​​of each array element, a composite pattern of the phased array antenna is formed. This composite pattern forms an adaptive null in the 120°E and 124°E GEO neighboring star directions, while maintaining the main lobe gain of the ground data transmission beam. The composite radiation pattern is obtained by summing the products of the composite weighted values ​​of each array element and the spatial phase factors of the corresponding array elements. The radiation pattern function is expressed by the following formula: ,in, Represents the complex pattern function, the elevation angle of the phased array antenna in space. and azimuth The total electric field radiation response in the direction; The pitch angle represents the angle between the far-field observation direction and the Z-axis of the antenna array, which is calculated after the GEO space vector is converted to the antenna body coordinate system in step S21. Represents the spatial azimuth angle, the angle between the projection of the far-field observation direction onto the XY plane of the array and the positive X-axis direction, and... Together they determine a unique spatial orientation; This represents a one-dimensional matrix element index, with values ​​ranging from 1 to... ; Indicates the total number of array elements; Indicates the first The optimal complex weighting value for each array element; The imaginary unit is used to construct the spatial phase factor in complex exponential form, and is given by the inherent rules of complex number operations; Indicates the operating wavelength; Indicates the first The X-coordinates of each array element; Indicates the first The Y-coordinates of each array element; Represents the spatial frequency component in the X direction; Represents the spatial frequency component in the Y direction; In the direction of incoming waves from GEO neighboring satellites, the pattern amplitude response is significantly suppressed, forming a deep null, since the composite weighted values ​​already include null compensation phase. In the direction of the main lobe of the data transmission to Earth, the composite weighted values ​​match the space steering vector, and the main lobe gain is maintained.

[0031] Step S3: Based on the composite pattern after superimposing the beam null compensation phase values, calculate the residual sidelobe level values ​​in the 120°E and 124°E GEO neighbor directions, and determine the power back-off amount of the Ku-band transmit link of the polar-orbiting satellite according to the coupling mapping relationship between the residual sidelobe level values ​​and the spatial isolation angle. Specifically, the amplitude response values ​​in the direction of incoming waves from the GEO neighboring satellite at 120°E and 124°E are extracted as residual sidelobe levels based on the synthetic pattern function. Combined with the deviation between the spatial isolation angle and the preset isolation angle threshold, the margin of the actual equivalent isotropic radiated power of the polar-orbiting satellite in the direction of the GEO neighboring satellite relative to the limit is determined. Then, based on the correspondence between this margin and the power back-off amount, the power back-off amount of the Ku-band transmit link is determined. This process includes the following sub-steps: Step S31: Based on the pattern function of the synthesized pattern, extract the pattern amplitude response value in the direction of incoming waves from the GEO neighboring star at 120°E and 124°E, and use this amplitude response value as the residual sidelobe level value. Step S32: Based on the deviation between the spatial isolation angle and the preset isolation angle threshold, and combined with the residual sidelobe level value, determine the margin of the actual equivalent isotropic radiation power of the polar-orbiting satellite in the direction of the GEO neighboring satellite relative to the limit. The spatial isolation angle reflects the angular distance between the main lobe of a polar-orbiting satellite and the direction of its GEO neighbor. When the spatial isolation angle is less than a preset threshold, the sidelobe radiation of the polar-orbiting satellite enters the sensitive region of the GEO neighbor. The deviation indicates the severity of the current interference. Meanwhile, the residual sidelobe level determines the actual radiation intensity of the polar-orbiting satellite in the direction of the GEO neighbor at a given spatial isolation angle. Combining the spatial isolation angle deviation with the residual sidelobe level, and then taking into account the current transmit power and main lobe gain, yields the margin of the actual equivalent isotropic radiated power of the polar-orbiting satellite in the direction of the GEO neighbor relative to the ITU EPFD limit.

[0032] Step S33: Determine the power back-off amount of the Ku-band transmit link based on the correspondence between the margin, power back-off amount, and spatial isolation angle; The power back-off amount is determined through a pre-calibrated coupling mapping lookup table. During ground testing, different spatial isolation angle values ​​are traversed to measure the corresponding residual sidelobe levels and the power back-off amount required to achieve EPFD compliance, forming a lookup table. The lookup table uses the spatial isolation angle as an index to record the power back-off amount corresponding to each calibration node. During on-orbit operation, the current back-off amount is determined by looking up this table based on the currently calculated spatial isolation angle. In this way, the power back-off amount changes continuously with the spatial isolation angle. When the margin is positive, the back-off amount is zero; when the margin is negative, the back-off amount increases with the increase of the absolute value of the margin, forming a linkage suppression effect where the smaller the isolation angle, the deeper the back-off.

[0033] Step S4: Based on the power back-off amount, dynamically back off the Ku-band transmit power, and inject the back-off transmit power and the composite radiation pattern into the downlink, so that the equivalent isotropic radiated power of the polar-orbiting satellite to the GEO neighboring satellite is reduced synchronously. Specifically, a transmit power control command is generated based on the power back-off amount. The output power of the power amplifier is adjusted to the target back-off value through the grid voltage adjustment port of the solid-state power amplifier in the Ku-band transmit link. At the same time, the transmit power after back-off is combined with the spatial gain distribution of the composite pattern to calculate the actual equivalent isotropic radiated power of the polar-orbiting satellite to the GEO neighbor satellite, ensuring that it meets the ITU EPFD limit requirements. The corresponding radio frequency signal is then fed into each element of the phased array antenna after composite pattern shaping and radiated out through the downlink. The specific steps include the following: Step S41: Generate a transmit power control command based on the power back-off amount, and adjust the power amplifier output power to the target power value after back-off through the grid voltage adjustment port of the solid-state power amplifier in the Ku-band transmit link. The target output power is calculated based on the power back-off amount, which is the rated output power minus the power back-off amount. The target output power is converted into a corresponding gate voltage control signal, which is then output to the gate voltage adjustment port of the solid-state power amplifier via a digital-to-analog converter, adjusting the amplifier's output power to the target value. During the power back-off process, the solid-state power amplifier operates in the linear region.

[0034] Step S42: Combine the backed-up transmit power with the spatial gain distribution of the composite pattern to calculate the actual equivalent isotropic radiation power of the polar-orbiting satellite toward the GEO neighboring satellite, so that the actual equivalent isotropic radiation power meets the ITU-EPFD limit requirements. The actual equivalent isotropic radiated power of a polar-orbiting satellite in the direction of its GEO neighbor is determined by both the back-off transmit power and the gain of the composite pattern in the GEO neighbor direction. The composite pattern has already achieved deep suppression in the GEO neighbor direction through null compensation. Combined with the dynamic back-off of the transmit power, both factors work together to reduce the actual equivalent isotropic radiated power. The actual equivalent isotropic radiated power of a polar-orbiting satellite in the direction of its GEO neighbor is expressed by the following formula: in, This represents the actual equivalent isotropic radiated power of a polar-orbiting satellite in the direction of its GEO neighbor after joint suppression; This represents the transmit power after the rollback output in step S41; This indicates the transmission loss of radio frequency signals from the transmitter to the antenna array; This indicates the polarization matching degree between the polar-orbiting satellite transmitting antenna and the GEO neighbor satellite receiving antenna, with a typical value range of 0.90 to 0.98. This indicates the gain of the phased array antenna in the main lobe-to-ground data transmission direction; Indicates the spatial orientation of the phased array antenna The complex electric field radiation response; This represents the elevation angle of the GEO neighboring satellite relative to the direction of the antenna array normal; express; This indicates the power radiation intensity of the antenna in the direction of the main lobe peak.

[0035] Step S43: The radio frequency signal corresponding to the back-off transmit power is fed into each element of the phased array antenna after being shaped by the synthesized pattern, and then radiated out through the downlink. The actual equivalent isotropic radiation power of a polar-orbiting satellite in the direction of its GEO neighbor is determined by both the back-off transmit power and the gain of the composite pattern in the GEO neighbor direction. The composite pattern has achieved deep suppression in the GEO neighbor direction through null compensation, and the dynamic back-off of the transmit power, together with the other two factors, reduces the actual equivalent isotropic radiation power.

[0036] Step S5: Perform a closed-loop comparison of the spatial isolation angle, residual sidelobe level, and power back-off with the ITU EPFD limit. When the spatial isolation angle crosses the isolation angle threshold, synchronously update the beam null compensation phase value and power back-off. Specifically, the spatial isolation angle at the current moment is compared with that at the previous moment to determine whether it has crossed the isolation angle threshold. If it has crossed, a synchronization update flag is triggered. The beam null compensation phase value in the direction of the GEO neighboring satellite is recalculated based on the spatial isolation angle after the crossing. At the same time, the power backoff amount is updated based on the re-extracted residual sidelobe level value. The updated compensation phase is superimposed on the Taylor weighted weight to generate a new synthetic weighted weight. The updated power backoff amount is fed into the transmit power control link to achieve synchronous adjustment of beam null depth and transmit power as the spatial isolation angle changes. The specific steps include the following: Step S51: Compare the spatial isolation angle at the current moment with the spatial isolation angle at the previous moment, and determine whether the spatial isolation angle has changed from being greater than the isolation angle threshold to being less than the isolation angle threshold, or from being less than the isolation angle threshold to being greater than the isolation angle threshold. If a crossover occurs, trigger the synchronization update flag. Polar-orbiting satellites move at high speed in a 97° inclination orbit, with the spatial isolation angle changing continuously over time. The determination method is as follows: if the isolation angle at the previous moment is greater than a preset threshold and the isolation angle at the current moment is less than a preset threshold, it is determined as entering a crossing; if the isolation angle at the previous moment is less than a preset threshold and the isolation angle at the current moment is greater than a preset threshold, it is determined as exiting a crossing. Both entering and exiting a crossing trigger a synchronization update flag.

[0037] Step S52: When the synchronization update flag is triggered, recalculate the beam null compensation phase value in the direction of the GEO neighboring star based on the spatial isolation angle at the current time after the crossing, and update the power backoff amount based on the re-extracted residual sidelobe level value. Following the crossing event, the spatial geometry between the polar-orbiting satellite and its GEO neighbor changed. The original beam null compensation phase value, calculated based on the spatial isolation angle before the crossing, is no longer applicable to the interference scenario after the crossing. Therefore, it is necessary to recalculate the incoming beam direction angle based on the current spatial vector, update the constraint steering vector, and recalculate the weighted values ​​to obtain the updated beam null compensation phase value. Simultaneously, the residual sidelobe levels in the direction of the GEO neighbor are re-extracted from the updated composite pattern, and the power backoff amount is re-determined based on the updated spatial isolation angle.

[0038] Step S53: Re-superimpose the updated beam null compensation phase value onto the Taylor weighting value to generate an updated composite weighting value, and feed the updated power back-off amount into the transmit power control link so that the beam null depth and transmit power are adjusted synchronously with the change of spatial isolation angle. The updated beam null compensation phase values ​​are re-superimposed onto the Taylor weighting values ​​using a complex multiplication-addition method to generate new composite weighting values, aligning the null direction of the composite pattern with the instantaneous position of the GEO neighbor after crossing. Simultaneously, the updated power backoff is converted into a gate voltage control signal to adjust the output power of the solid-state power amplifier. This synchronized updating of beam null and power backoff ensures that they remain consistent throughout the entire process of crossing the spatial isolation angle threshold—the null depth adaptively adjusts with changes in the GEO neighbor direction, and the transmit power dynamically backs off or recovers as the interference status rises or falls.

[0039] Example 2 like Figure 2 As shown, Embodiment 2 of this application provides a joint suppression system for EPFD of a polar-orbiting satellite against a GEO neighboring satellite, comprising: Orbit Calculation Module 21: Based on the real-time ephemeris of the polar-orbiting satellite's 97° inclination orbit, calculates the spatial isolation angle between the polar-orbiting satellite and its GEO neighboring satellites at 120°E and 124°E, and compares this spatial isolation angle with a preset isolation angle threshold in real time; includes the following sub-modules: Ephemeris Data Generation Submodule 211: Based on the real-time position and velocity information output by the onboard GNSS receiver of the polar-orbiting satellite, and combined with the 97° inclination orbital elements of the polar-orbiting satellite, calculate the instantaneous orbital parameters of the polar-orbiting satellite, and generate real-time ephemeris data of the satellite. Space isolation angle calculation submodule 212: Based on the real-time ephemeris data of the satellite, determine the space vector from the phase center of the polar-orbiting satellite antenna to the 120°E and 124°E GEO neighboring satellite orbit positions, and calculate the space isolation angle based on the angle between the space vector and the polar-orbiting satellite's Earth pointing vector; Threshold Comparison and Status Identification Submodule 213: Compares the calculated spatial isolation angle with the preset isolation angle threshold, determines in real time whether the spatial isolation angle is less than the isolation angle threshold, and generates an isolation angle status identification; Beam nulling module 22: When the spatial isolation angle is less than the isolation angle threshold, based on the Taylor weighting value of the phased array antenna, the beam nulling compensation phase value in the direction of the GEO neighboring satellite at 120°E or 124°E is calculated according to the spatial isolation angle. This beam nulling compensation phase value is superimposed on the Taylor weighting value to generate a composite weighting value, and the composite radiation pattern is calculated based on this composite weighting value; including the following sub-modules: Space steering vector determination submodule 221: Determine the space steering vector of the GEO neighboring satellite based on the incoming wave direction angle of the GEO neighboring satellite relative to the normal direction of the polar-orbiting satellite phased array antenna at 120°E or 124°E. Beam null compensation phase value calculation submodule 222: Based on the space steering vector, the beam null compensation phase value in the direction of the 120°E or 124°E GEO neighboring star is calculated using the minimum variance distortionless response criterion, and the beam null compensation phase value is superimposed on the Taylor weighted weight of each array element in a complex multiplication-addition manner to generate a composite weighted weight. Synthetic pattern generation submodule 223: Based on the synthetic weighting values ​​of each array element, a synthetic pattern of the phased array antenna is formed. This synthetic pattern forms an adaptive null in the 120°E and 124°E GEO neighboring star directions, while maintaining the main lobe gain of the ground data transmission beam. Power back-off module 23: Based on the composite radiation pattern obtained by superimposing the beam null compensation phase values, calculates the residual sidelobe levels in the 120°E and 124°E GEO neighbor directions, and determines the power back-off amount of the Ku-band transmit link for polar-orbiting satellites based on the coupling mapping relationship between the residual sidelobe levels and the spatial isolation angle; includes the following sub-modules: Residual sidelobe level extraction submodule 231: Based on the pattern function of the synthesized pattern, extract the pattern amplitude response value in the direction of incoming waves from neighboring stars at 120°E and 124°EGEO, and use the amplitude response value as the residual sidelobe level value; EIRP margin calculation submodule 232: Based on the deviation between the spatial isolation angle and the preset isolation angle threshold, and combined with the residual sidelobe level value, determine the margin of the actual equivalent isotropic radiated power of the polar-orbiting satellite in the direction of the GEO neighboring satellite relative to the limit. Power back-off determination submodule 233: Based on the margin and the correspondence between power back-off and spatial isolation angle, determine the power back-off amount of the Ku-band transmit link; Link power control and injection module 24: Based on the power back-off amount, dynamically backs up the Ku-band transmit power and injects the backed-off transmit power and the composite radiation pattern into the downlink, so that the equivalent isotropic radiated power of the polar-orbiting satellite to its GEO neighbor satellite is reduced synchronously; including the following sub-modules: Power amplifier power adjustment submodule 241: Generates transmit power control command based on power back-off amount, and adjusts the power amplifier output power to the target power value after back-off through the gate voltage adjustment port of the solid-state power amplifier of the Ku-band transmit link; EIRP Composite Calculation Submodule 242: Combines the back-off transmit power with the spatial gain distribution of the composite pattern to obtain the actual equivalent isotropic radiation power of the polar-orbiting satellite toward the GEO neighboring satellite, so that the actual equivalent isotropic radiation power meets the ITU EPFD limit requirements; RF signal feeding and radiation submodule 243: After the RF signal corresponding to the back-off transmit power is shaped into a composite pattern, it is fed into each element of the phased array antenna and radiated out through the downlink. Closed-loop update module 25: performs a closed-loop comparison of the spatial isolation angle, residual sidelobe level, and power back-off with the ITU EPFD limits. When the spatial isolation angle crosses the isolation angle threshold, it synchronously updates the beam null compensation phase value and power back-off. It includes the following sub-modules: Crossing event detection submodule 251: Compare the spatial isolation angle at the current moment with the spatial isolation angle at the previous moment, and determine whether the spatial isolation angle has changed from being greater than the isolation angle threshold to being less than the isolation angle threshold, or from being less than the isolation angle threshold to being greater than the isolation angle threshold. If a crossing occurs, the synchronization update flag is triggered. Parameter recalculation submodule 252: When the synchronization update flag is triggered, the beam null compensation phase value in the direction of the GEO neighboring star is recalculated based on the spatial isolation angle at the current time after the crossing, and the power backoff amount is updated based on the re-extracted residual sidelobe level value. Synchronous update execution submodule 253: The updated beam null compensation phase value is re-superimposed on the Taylor weighted value to generate an updated synthetic weighted value, and the updated power back-off amount is fed into the transmit power control link so that the beam null depth and transmit power are synchronously adjusted with the change of spatial isolation angle.

Claims

1. A method for joint suppression of EPFD by polar-orbiting satellites on GEO neighboring satellites, characterized in that, include: S1. Based on the real-time ephemeris of the polar-orbiting satellite's 97° inclination orbit, calculate the spatial isolation angle between the polar-orbiting satellite and its neighboring GEO satellites at 120°E and 124°E, and compare this spatial isolation angle with a preset isolation angle threshold in real time. S2. When the spatial isolation angle is less than the isolation angle threshold, based on the Taylor weighting weight of the phased array antenna, calculate the beam null compensation phase value in the direction of the GEO neighboring star at 120°E or 124°E according to the spatial isolation angle, superimpose the beam null compensation phase value onto the Taylor weighting weight to generate the composite weighting weight, and calculate the composite pattern based on the composite weighting weight. S3. Based on the composite pattern after superimposing the beam null compensation phase values, calculate the residual sidelobe level values ​​in the 120°E and 124°E GEO neighbor directions, and determine the power back-off amount of the Ku-band transmit link for polar-orbiting satellites based on the coupling mapping relationship between the residual sidelobe level values ​​and the spatial isolation angle. S4. Based on the power back-off amount, the Ku-band transmit power is dynamically backed off, and the backed-off transmit power and the composite radiation pattern are injected into the downlink together, so that the equivalent isotropic radiation power of the polar-orbiting satellite to the GEO neighboring satellite is reduced synchronously. S5. Perform a closed-loop comparison of the spatial isolation angle, residual sidelobe level, and power back-off with the ITU EPFD limit. When the spatial isolation angle crosses the isolation angle threshold, synchronously update the beam null compensation phase value and power back-off.

2. The method for joint suppression of EPFD by polar-orbiting satellites on GEO neighboring satellites according to claim 1, characterized in that, Based on the real-time ephemeris of the polar-orbiting satellite's 97° inclination orbit, the spatial isolation angle between the polar-orbiting satellite and its GEO neighboring satellites at 120°E and 124°E is calculated, and this spatial isolation angle is compared in real time with a preset isolation angle threshold. This includes the following sub-steps: Based on the real-time position and velocity information output by the onboard GNSS receiver of the polar-orbiting satellite, and combined with the orbital elements at a 97° inclination angle of the polar-orbiting satellite, the instantaneous orbital parameters of the polar-orbiting satellite are calculated, and real-time ephemeris data of the satellite is generated. Based on real-time satellite ephemeris data, the spatial vector from the phase center of the polar-orbiting satellite antenna to the GEO neighboring satellite orbit positions at 120°E and 124°E is determined, and the spatial isolation angle is calculated based on the angle between this spatial vector and the polar-orbiting satellite's Earth pointing vector. The calculated spatial isolation angle is compared with the preset isolation angle threshold, and it is determined in real time whether the spatial isolation angle is less than the isolation angle threshold, and an isolation angle status indicator is generated.

3. The method for joint suppression of EPFD by a polar-orbiting satellite and a GEO neighboring satellite according to claim 1, characterized in that, When the spatial isolation angle is less than the isolation angle threshold, based on the Taylor weighted weights of the phased array antenna, the beam null compensation phase value in the direction of the GEO neighboring satellite at 120°E or 124°E is calculated according to the spatial isolation angle. This beam null compensation phase value is then superimposed on the Taylor weighted weights to generate a composite weighted value. The composite radiation pattern is then calculated based on this composite weighted value, including the following sub-steps: The spatial steering vector of the GEO neighbor is determined based on the incoming wave direction angle of the GEO neighbor relative to the normal direction of the phased array antenna of the polar-orbiting satellite at 120°E or 124°E. Based on the spatial steering vector, the beam null compensation phase value in the direction of the GEO neighboring star at 120°E or 124°E is calculated using the minimum variance distortionless response criterion. The beam null compensation phase value is then superimposed on the Taylor weighted weight of each array element in a complex multiplication-addition manner to generate a composite weighted weight. Based on the combined weighting values ​​of each array element, a composite radiation pattern of the phased array antenna is formed. This composite radiation pattern forms an adaptive null in the 120°E and 124°E GEO neighboring satellite directions, while maintaining the main lobe gain of the ground data transmission beam.

4. The method for joint suppression of EPFD by a polar-orbiting satellite against a GEO neighboring satellite according to claim 1, characterized in that, Based on the composite radiation pattern obtained by superimposing the beam null compensation phase values, the residual sidelobe levels in the 120°E and 124°E GEO neighbor directions are calculated. Then, based on the coupling mapping relationship between these residual sidelobe levels and the spatial isolation angle, the power back-off amount of the Ku-band transmit link for polar-orbiting satellites is determined, including the following sub-steps: Based on the pattern function of the composite pattern, the pattern amplitude response values ​​in the direction of incoming waves from the GEO neighboring star at 120°E and 124°E are extracted, and these amplitude response values ​​are used as the residual sidelobe level values. Based on the deviation between the spatial isolation angle and the preset isolation angle threshold, and combined with the residual sidelobe level, the margin of the actual equivalent isotropic radiated power of the polar-orbiting satellite in the direction of the GEO neighboring satellite is determined relative to the limit. Based on the correspondence between margin, power back-off, and spatial isolation angle, the power back-off amount of the Ku-band transmit link is determined.

5. A method for joint suppression of EPFD by a polar-orbiting satellite against a GEO neighboring satellite according to claim 1, characterized in that, Based on the power back-off amount, the Ku-band transmit power is dynamically backed off, and the backed-off transmit power, along with the composite radiation pattern, is injected into the downlink to synchronously reduce the equivalent isotropic radiated power of the polar-orbiting satellite to its GEO neighbor. This includes the following sub-steps: Based on the power back-off amount, a transmit power control command is generated, and the output power of the power amplifier is adjusted to the target power value after back-off through the gate voltage adjustment port of the solid-state power amplifier in the Ku-band transmit link. The backed-up transmit power and the spatial gain distribution of the composite pattern are combined and calculated to obtain the actual equivalent isotropic radiation power of the polar-orbiting satellite toward the GEO neighboring satellite, so that the actual equivalent isotropic radiation power meets the ITU EPFD limit requirements. The radio frequency signal corresponding to the back-off transmit power is fed into each element of the phased array antenna after being shaped by the synthesized radiation pattern, and then radiated out through the downlink.

6. The method for joint suppression of EPFD by polar-orbiting satellites on GEO neighboring satellites according to claim 1, characterized in that, The spatial isolation angle, residual sidelobe level, and power back-off are compared with the ITU EPFD limits in a closed loop. When the spatial isolation angle crosses the isolation angle threshold, the beam null compensation phase value and power back-off are updated synchronously, including the following sub-steps: Compare the spatial isolation angle at the current moment with the spatial isolation angle at the previous moment, and determine whether the spatial isolation angle has changed from being greater than the isolation angle threshold to being less than the isolation angle threshold, or from being less than the isolation angle threshold to being greater than the isolation angle threshold. If a crossover occurs, the synchronization update flag is triggered. When the synchronization update flag is triggered, the beam null compensation phase value in the direction of the GEO neighboring star is recalculated based on the spatial isolation angle at the current moment after the crossing, and the power backoff amount is updated based on the re-extracted residual sidelobe level value. The updated beam null compensation phase value is re-superimposed onto the Taylor weighting value to generate an updated composite weighting value, and the updated power back-off amount is fed into the transmit power control link so that the beam null depth and transmit power are adjusted synchronously with the change of spatial isolation angle.

7. A method for joint suppression of EPFD by a polar-orbiting satellite on a GEO neighboring satellite according to claim 3, characterized in that, Based on the spatial steering vector, the beam null compensation phase value in the direction of the GEO neighboring star at 120°E or 124°E is calculated using the minimum variance distortionless response criterion. This beam null compensation phase value is then superimposed onto the Taylor weighted weights of each array element using a complex multiplication-addition method to generate a composite weighted value. The process includes the following sub-steps: Based on the geometric characteristics of the full-latitude swept GEO orbit of the polar-orbiting satellite at an inclination of 97°, the spatial phase difference between the 120°E and 124°EGEO neighboring satellites and the phased array antenna surface of the polar-orbiting satellite is dynamically updated, and this spatial phase difference is introduced into the beamformer as a null constraint condition. Under the Taylor-weighted low sidelobe constraint, a linear constraint minimum variance optimization problem is constructed based on the null constraint condition. Solving this optimization problem yields the beam null compensation phase value for each array element. The solved beam null compensation phase value is superimposed with the Taylor weighted value of the corresponding array element by complex multiplication to generate a composite weighted value, so that the composite pattern forms an adaptive null in the direction of the GEO neighbor while maintaining low sidelobe characteristics.

8. A polar-orbiting satellite-GEO neighbor satellite EPFD joint suppression system, characterized in that, include: The orbit calculation module calculates the spatial isolation angle between the polar-orbiting satellite and its neighboring satellites at 120°E and 124°EGEO based on the real-time ephemeris of the 97° inclination orbit of the polar-orbiting satellite, and compares the spatial isolation angle with the preset isolation angle threshold in real time. Beam nulling module: When the spatial isolation angle is less than the isolation angle threshold, the beam nulling compensation phase value in the direction of the GEO neighboring star at 120°E or 124°E is calculated based on the Taylor weighting weight of the phased array antenna. This beam nulling compensation phase value is then superimposed on the Taylor weighting weight to generate a composite weighting weight, and the composite radiation pattern is calculated based on this composite weighting weight. Power back-off module: Based on the composite pattern after superimposing the beam null compensation phase values, calculate the residual sidelobe level values ​​in the 120°E and 124°E GEO neighbor directions, and determine the power back-off amount of the Ku-band transmit link of the polar-orbiting satellite according to the coupling mapping relationship between the residual sidelobe level value and the spatial isolation angle. Link power control and injection module: Based on the power back-off amount, the Ku-band transmit power is dynamically backed off, and the backed-off transmit power and the composite radiation pattern are injected into the downlink together, so that the equivalent isotropic radiation power of the polar-orbiting satellite to the GEO neighboring satellite is reduced synchronously. Closed-loop update module: The spatial isolation angle, residual sidelobe level, and power back-off are compared with the ITU EPFD limit in a closed loop. When the spatial isolation angle crosses the isolation angle threshold, the beam null compensation phase value and power back-off are updated synchronously.

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