Beam forming method and device based on phased array feed source reflector antenna and medium

Abstract

The invention relates to the technical field of satellite communication, and discloses a beam forming method and device based on a phased array feed source reflector antenna and a medium. The method comprises the following steps: acquiring first beam information of a satellite in first operation time and second beam information of the satellite in second operation time; under the condition that the current operation time is between the first operation time and the second operation time, determining angle information of the target area relative to the satellite based on ephemeris information of the current operation time and the area position of the target area; determining target beam position pointing information which is most matched with the angle information in the first beam information; performing linear interpolation on beam forming parameters indicated by the target beam position pointing information in the first beam information and the second beam information to obtain beam forming parameters of the target area and generate beams; the advantages of a phased-array antenna and a reflector antenna can be integrated, the beam forming capability of a large-aperture reflector antenna is improved, and a satellite has the capability of flexibly switching ground terminal beams and staring as required.

Description

Technical Field

[0001] The present disclosure relates to the field of satellite communication technologies, and in particular, to a beamforming method, apparatus, and medium based on a phased array feed reflector antenna. Background Art

[0002] A beam is a directional coverage area formed by the electromagnetic wave energy emitted by a satellite antenna in space. By adjusting the directivity and transmission parameters of the antenna, the satellite focuses the signal on a specific geographical area (such as a city, a country, or the ocean). Since the satellite development cycle is long, the cost is high, and the on-orbit service time is long, it is necessary for the satellite to have the reconfigurability as much as possible, that is, it can adjust parameters such as the pointing and power of multiple beams in real time according to user needs, so that the coverage range and shape of the beam can be dynamically adjusted according to requirements to achieve efficient communication or data transmission and improve the service capacity of the satellite system.

[0003] Traditional beamforming methods include two types: First, the phased array technology is used to achieve beam coverage for low-earth orbit satellites; Second, the array feed reflector antenna technology is used to achieve beam coverage for geostationary orbit and high-earth orbit satellites represented by Tiantong satellites, so as to achieve a certain beam control ability while obtaining high transmission gain. The following introduces these two beamforming methods separately.

[0004] For the phased array technology in the first method, it is implemented based on a phased array antenna. The phased array antenna is composed of multiple radiating array elements arranged. The radiating array elements are used to convert an electrical signal into an electromagnetic wave when transmitting a signal and convert the electromagnetic wave into an electrical signal when receiving a signal. The beamforming network connected to the phased array antenna adjusts the signal parameters (including amplitude and phase) of each element, so that the electromagnetic waves output by all elements are coherently superimposed in space to form a beam in a specific direction, thereby realizing flexible control of the number and shape of the beam and fast beam scanning (that is, the ability to change the beam pointing within milliseconds).

[0005] However, the all-digital array structure in which all radiating array elements can be independently controlled in terms of amplitude and phase is relatively complex, and the production difficulty is large when the number of radiating array elements is large. Therefore, a digital-analog hybrid structure is usually adopted in practical applications.

[0006] The digital-analog hybrid structure includes: a baseband processing layer, a radio frequency link layer, and an analog precoding layer. Among them, the baseband processing layer is used to: generate a baseband signal (raw data signal) and perform digital precoding (weighting and combining the signal) to obtain multiple digital signals, and each digital signal corresponds to a radio frequency link. The radio frequency link layer is used to convert the digital baseband signal into a radio frequency signal to obtain the radio frequency signal corresponding to each digital signal, and the number of radio frequency signals is equal to the number of radio frequency links (for example, 4 links output 4 radio frequency signals). Each radio frequency link corresponds to an independent hardware channel, and this hardware channel is used to connect the digital baseband to the analog antenna array. The analog precoding layer is connected to the radio frequency link and the radiation elements respectively, and is used to distribute the signal of each radio frequency link to multiple radiation elements through an analog network (such as a phase shifter), so as to adjust the signal phase of each element through the phase shifter and achieve beam pointing control.

[0007] However, according to the above digital-analog hybrid structure, the number of beams generated is limited by the number of radio frequency links. Based on this, the digital-analog hybrid array can be further divided into a fully connected structure and a sub-connected structure. The fully connected structure means that each radio frequency link is connected to all radiation elements through an analog network (such as a phase shifter). In the fully connected structure, the phase of all radiation elements can be adjusted after each radio frequency link. In the sub-connected structure, each radio frequency link is only connected to a sub-array of the elements (for example, 64 elements are divided into 4 groups, and each group of 16 elements is controlled by 1 link), that is, in the sub-connected structure, only the phase of some radiation elements in the array can be adjusted after each radio frequency link.

[0008] In an existing beamforming method applicable to the fully connected structure, the analog domain coding is designed through equal gain transmission (EGT), and then the digital domain coding is iteratively solved. In a beamforming method applicable to the sub-connected structure, compared with the fully connected structure, the difference is that the analog precoding matrix is sparser. However, as the array aperture increases, the number of phase shifters required for the fully connected structure increases rapidly, while the sub-connected structure has a large gain loss compared with the fully digital array. In addition, there are still some limitations in the production processes such as heat dissipation and deployment of large-aperture phased array antennas at present. Therefore, there are still some difficulties in the phased array deployment of medium and high earth orbit satellites.

[0009] In summary, in the beamforming method based on phased array antennas, spaceborne phased arrays are mainly deployed on low earth orbit satellites with an orbital altitude lower than 2000 km. At this time, the scale of the phased array is small and the circuit complexity is low. The orbital altitude of medium and high earth orbit satellites is dozens of times that of low earth orbit satellites, and the corresponding array aperture is also increased several times. The area of the low-frequency phased array can reach 20 m 2, at this time, the scale of the phased array is large, and the existing deployment technology and thermal control technology are not yet mature, making it difficult to deploy the phased array on medium and high-orbit satellites. In addition, the beamforming calculation complexity of a large-aperture phased array increases accordingly, making it difficult to adapt to medium and high-orbit satellites.

[0010] For the array-fed reflector antenna in the second method, it includes a reflector and a feed. The feed includes multiple feeding units near the focus of the reflector. The feeding units are used to transmit signals to the reflector or receive the signals focused by the reflector; the reflector is used to reflect electromagnetic waves to focus the energy radiated by the feed into a directional beam. Due to its advantages such as simple structure, mature processing technology, high gain, low cost, and multiple beam numbers, the array-fed reflector antenna has been widely used in fixed-beam coverage communication of high-orbit and geosynchronous orbit satellites.

[0011] The beamforming methods based on the array-fed reflector antenna include: the basic beamforming method and the enhanced beamforming method.

[0012] The basic beamforming method: It refers to a beamforming method in which a single feeding unit directly and independently irradiates the reflector to form a point beam. At this time, if the feed contains multiple feeding units, multiple beams can be generated simultaneously. This scheme has the advantages of high radiation efficiency and simple feeding, and can generate a relatively large number of beams at the same time. However, the beam direction of the basic beamforming method is determined by the physical position of the feeding unit and cannot be electronically adjusted in real time, which results in poor beam directivity of this method and makes it difficult to achieve beam reconfiguration and on-demand coverage of ground areas.

[0013] The enhanced beamforming method: It refers to a beamforming method in which multiple feeding units are used to cooperate in irradiating the reflector, and the required amplitude and phase are excited to multiple feeding units through a beamforming network to adjust the synthesized point beam. This method has the ability to flexibly control the number and shape of beams and can cover irregular areas. However, in the case of the same beam coverage, since each beam requires multiple feeding units to participate, the enhanced beamforming method requires several times the number of feeding units of the basic beamforming method, resulting in a more complex feeding network. At the same time, since the total power of the beam is shared by all feeding units, the power of a single beam is limited by the number of feeding units participating in the synthesized beam. And the beam switching speed depends on the analog phase shifter and cannot achieve nanosecond-level switching like a digital phased array, so the beam switching speed is limited.

[0014] In summary, existing spaceborne reflector antennas mostly adopt a fixed beam coverage mode, using a single feed or multiple feeds per beam combined with feed multiplexing technology. The reflector technology is relatively mature and the manufacturing cost is low, which can provide a high transmit gain for medium and high earth orbit satellites. However, such antennas usually do not have the ability of beam reconfiguration, and the beamforming and switching capabilities are limited. As the satellite's position changes, the beam coverage area also changes simultaneously, and it is impossible to maintain a long-term stare at the same user area, resulting in limited performance in application modes such as terminal direct connection.

[0015] In order to combine the advantages of flexible phased array beam control and high gain and low cost of the reflector, a phased array feed reflector (PAFR) antenna is proposed. This antenna uses a small phased array antenna as the feed, and uses the reflector to magnify the equivalent aperture of the primary feed array, so as to obtain higher gain and narrower beams. Since the amplitude and phase of each element of the phased array feed are independently controllable, this type of antenna has a high design freedom, can achieve fast beam agility and beamforming capabilities, and has the advantage of low cost compared with phased array antennas. The phased array feed reflector antenna has the advantage of being applied to medium and high earth orbit satellites that provide dynamic beam coverage services for low receive gain terminals. However, there is currently little research on phased array feed reflector antennas, and there is still a lack of beamforming and switching methods for them. Summary of the Invention

[0016] In view of this, the present disclosure proposes a beamforming method, device and medium based on a phased array feed reflector antenna, which can combine the advantages of flexible phased array beam control and high gain of the reflector antenna, improve the beamforming and switching capabilities of large-aperture reflector antennas, and enable medium and high earth orbit satellites to have the ability of flexible beam switching and on-demand staring at ground terminals.

[0017] According to one aspect of the present disclosure, there is provided a beamforming method based on a phased array feed reflector antenna, the method comprising:

[0018] When the satellite needs to serve at least one target area simultaneously, obtaining first beam information of the satellite at a first operating time and second beam information at a second operating time; wherein, the first beam information and the second beam information include wave position pointing information and beamforming parameters corresponding to each target area; the second operating time is after the first operating time and is separated from the first operating time by a preset time period;

[0019] For each target area, when the current operating time of the satellite is between the first operating time and the second operating time, determining angle information of the target area relative to the satellite based on the ephemeris information at the current operating time and the regional position of the target area;

[0020] Determine the target wave position pointing information in the first beam information that best matches the angle information;

[0021] Perform linear interpolation on the beamforming parameters indicated by the target wave position pointing information in the first beam information and the second beam information to obtain the beamforming parameters for the target area;

[0022] Control the phased array feed reflector antenna to generate a beam for the target area according to the beamforming parameters to provide services for the target area.

[0023] In a possible implementation, after controlling the phased array feed reflector antenna to generate a beam for the target area according to the beamforming parameters, it further includes:

[0024] Determine whether to continue to provide services for the at least one target area;

[0025] In the case of determining to continue to provide services, if the current operating time of the satellite is between the first operating time and the second operating time, trigger the execution of the step of determining the angle information of the target area relative to the satellite based on the ephemeris information of the current operating time and the regional position of the target area and the subsequent steps;

[0026] In the case where the current operating time of the satellite is greater than or equal to the second operating time, replace the first operating time with the second operating time, replace the second operating time with the first operating time plus a preset duration, and trigger the execution of the step of obtaining the first beam information of the satellite at the first operating time and the second beam information at the second operating time and the subsequent steps;

[0027] In the case of determining to stop providing services, send the regional positions of the at least one target area to the next satellite for the next satellite to obtain the first beam information at the first operating time and the second beam information at the second operating time, and generate the beamforming parameters for the target area based on the regional positions.

[0028] In a possible implementation, the obtaining the first beam information of the satellite at the first operating time and the second beam information at the second operating time includes:

[0029] For each target area, obtain the beamforming matrix to be updated for the target area and the channel transmission matrix corresponding to the wave position pointing information of the target area at the target operating time; wherein, when the target operating time is the first operating time, the wave position pointing information is the wave position pointing information in the first beam information; when the target operating time is the second operating time, the wave position pointing information is the wave position pointing information in the second beam information;

[0030] Based on the beamforming matrix to be updated and the channel transmission matrix, determine the minimum mean square error receiver for the target area;

[0031] Based on the minimum mean square error receiver and the priority weight of the target area, determine the weighting matrix;

[0032] Update the beamforming matrix to be updated based on the weighting matrix to obtain the updated beamforming matrix;

[0033] Normalize the updated beamforming matrix so that the updated beamforming matrix satisfies the preset power constraint condition;

[0034] Determine whether the normalized beamforming matrix satisfies the preset convergence condition;

[0035] If the convergence condition is satisfied, determine the beamforming parameter corresponding to the wave position pointing information as the normalized beamforming matrix; wherein, when the wave position pointing information is the wave position pointing information in the first beam information, the beamforming parameter is the beamforming parameter corresponding to the wave position pointing information in the first beam information; when the wave position pointing information is the wave position pointing information in the second beam information, the beamforming parameter is the beamforming parameter corresponding to the wave position pointing information in the second beam information;

[0036] If the convergence condition is not satisfied, use the normalized beamforming matrix as the beamforming matrix to be updated, and trigger the execution of the steps of determining the minimum mean square error receiver for the target area based on the beamforming matrix to be updated and the channel transmission matrix and the subsequent steps.

[0037] In a possible implementation, the determination of the minimum mean square error receiver for the target area based on the beamforming matrix to be updated and the channel transmission matrix is represented by the following formula:

[0038]

[0039] B i =RF i ;

[0040] Among them, represents the minimum mean square error (MMSE) receiver for the target area k; F k represents the beamforming matrix to be updated for the target area k; F i represents the beamforming matrix to be updated for the target area i; i is a positive integer taking values from 1 to K in sequence, k represents any integer from 1 to K; K represents the total number of target areas; H k represents the channel transmission matrix corresponding to the wave position pointing information of the target area k at the target operation time; R represents the illumination matrix; I represents the identity matrix; σ 2 represents the noise power; the superscript H represents the conjugate transpose of the matrix;

[0041] Correspondingly, the weighted matrix is determined based on the minimum mean square error receiver and the priority weight of the target area, and is expressed by the following formula:

[0042]

[0043] Among them, represents the weighted matrix of the target area k; α k represents the priority weight of the target area k; E k represents the mean square error of the target area k;

[0044] Correspondingly, the beamforming matrix to be updated is updated based on the updated weighted matrix to obtain the updated beamforming matrix, which is expressed by the following formula:

[0045]

[0046] Among them, F k ’ represents the updated beamforming matrix of the target area k; represents the minimum mean square error (MMSE) receiver of the target area i; represents the weighted matrix of the target area i; Tr(·) represents the trace of the matrix; P = P max , P max represents the preset maximum power.

[0047] In a possible implementation manner, the power constraint condition is expressed by the following formula:

[0048]

[0049] Among them, P max represents the preset maximum power; F kDenote the updated beamforming matrix for the target area k; k represents any integer from 1 to K; K represents the total number of target areas; R represents the illumination matrix; Tr(·) represents the trace of a matrix; the superscript H represents the conjugate transpose of a matrix.

[0050] In a possible implementation, the same set of first beam information and the second beam information for the same target area are associated based on the same beam index; correspondingly,

[0051] The linear interpolation of the beamforming parameters indicated by the target wave position pointing information in the first beam information and the second beam information to obtain the beamforming parameters of the target area includes:

[0052] Determine the first beamforming parameter corresponding to the target wave position pointing information in the first beam information;

[0053] Obtain the beam index of the first beam information;

[0054] Determine the second beamforming parameter in the second beam information associated with the beam index;

[0055] Perform linear interpolation on the first beamforming parameter and the second beamforming parameter to obtain the beamforming parameters of the target area.

[0056] In a possible implementation, the linear interpolation of the first beamforming parameter and the second beamforming parameter to obtain the beamforming parameters of the target area is represented by the following formula:

[0057] F″ = F0 + α(F1 - F0);

[0058] α = (t″ - t) / (t′ - t);

[0059] where F″ represents the beamforming parameters of the target area; F0 represents the first beamforming parameter; F1 represents the second beamforming parameter; α represents the update factor; t″ represents the current running time; t′ represents the second running time; t represents the first running time.

[0060] According to another aspect of the present disclosure, there is provided a beamforming device based on a phased array feed reflector antenna, including a memory, a processor, and a computer program stored on the memory, and the processor executes the computer program to implement the steps of the above method.

[0061] According to another aspect of the present disclosure, there is provided a non - volatile computer - readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above method are implemented.

[0062] According to another aspect of the present disclosure, there is provided a computer program product including a computer program or a non-volatile computer-readable storage medium carrying the computer program. When the computer program is executed by a processor, the steps of the above method are implemented.

[0063] When the satellite needs to serve at least one target area simultaneously, acquire the first beam information of the satellite at the first operating time and the second beam information at the second operating time; wherein, the first beam information and the second beam information include the wave position pointing information and beamforming parameters corresponding to each target area; for each target area, when the current operating time of the satellite is between the first operating time and the second operating time, determine the angle information of the target area relative to the satellite based on the ephemeris information at the current operating time and the regional position of the target area; determine the target wave position pointing information in the first beam information that best matches the angle information; perform linear interpolation on the beamforming parameters indicated by the target wave position pointing information in the first beam information and the second beam information to obtain the beamforming parameters of the target area; control the phased array feed reflector antenna to generate a beam for the target area according to the beamforming parameters to provide service for the target area. A beamforming method based on a phased array feed reflector antenna is provided, which can integrate the advantages of flexible control of the phased array antenna beam and high gain of the reflector antenna, improve the beamforming and switching capabilities of a large-aperture reflector antenna, enable medium and high-earth orbit satellites to have the ability of flexible beam switching and on-demand staring for ground terminals, provide a feasible solution for the application of medium and high-earth orbit satellites in the low-frequency band (such as the 1-2 GHz band), and enable medium and high-earth orbit satellites to provide direct connection services for ground terminal users on demand.

[0064] According to the following detailed description of the exemplary embodiments with reference to the accompanying drawings, other features and aspects of the present disclosure will become clear. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] The accompanying drawings, which are included in and constitute a part of this specification, illustrate the exemplary embodiments, features, and aspects of the present disclosure together with the specification and are used to explain the principles of the present disclosure.

[0066] Figure 1 The flowchart showing a beamforming method based on a phased array feed reflector antenna according to an embodiment of the present disclosure;

[0067] Figure 2 The schematic diagram showing an application scenario of a satellite based on a phased array feed reflector antenna according to an embodiment of the present disclosure;

[0068] Figure 3 The schematic diagram showing the type of parameters stored in a satellite according to an embodiment of the present disclosure;

[0069] Figure 4A schematic diagram showing a beamforming iterative process according to an embodiment of the present disclosure;

[0070] Figure 5 A flowchart showing a beamforming method based on a phased array feed reflector antenna according to another embodiment of the present disclosure;

[0071] Figure 6 A block diagram showing a beamforming device based on a phased array feed reflector antenna according to an embodiment of the present disclosure;

[0072] Figure 7 A block diagram showing a beamforming device based on a phased array feed reflector antenna according to another embodiment of the present disclosure. Detailed Description of Specific Embodiments

[0073] Various exemplary embodiments, features, and aspects of the present disclosure will be described in detail below with reference to the accompanying drawings. Identical reference numerals in the drawings denote elements having the same or similar functions. Although various aspects of the embodiments are shown in the drawings, the drawings do not have to be drawn to scale unless otherwise specified.

[0074] As used herein, the terms "comprising," "including," "having," or variations thereof are open-ended and include one or more stated features, wholes, elements, steps, components, or functions, but do not exclude the presence or addition of one or more other features, wholes, elements, steps, components, functions, or groups thereof.

[0075] When an element is referred to as being "connected," "coupled," "responsive," or variations thereof to another element, it can be directly connected, coupled, or responsive to the other element, or intervening elements may be present.

[0076] Although the terms first, second, third, etc. may be used herein to describe various elements / operations, these elements / operations should not be limited by these terms. These terms are only used to distinguish one element / operation from another. Thus, without departing from the teachings of the inventive concept, a first element / operation in some embodiments may be referred to as a second element / operation in other embodiments.

[0077] The term "exemplary" as used herein means "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" need not be construed as superior to or better than other embodiments.

[0078] In addition, for a better illustration of the present disclosure, numerous specific details are given in the following detailed description of specific embodiments. Those skilled in the art should understand that the present disclosure can be implemented without some of these specific details. In some instances, methods, means, elements, and circuits well-known to those skilled in the art are not described in detail so as to highlight the gist of the present disclosure.

[0079] Figure 1 A flowchart showing a beamforming method for a phased array feed reflector antenna according to an embodiment of the present disclosure. Since the field of view of the phased array feed reflector antenna is limited, usually about ±10°, and this field of view range is close to that of medium-earth orbit satellites and geostationary orbit satellites. Therefore, this embodiment takes the application of this method in medium-earth orbit satellites or geostationary orbit satellites as an example for illustration. In actual implementation, if the field of view range of the phased array feed reflector antenna is expanded, and the expanded field of view range is close to that of low-earth orbit satellites (for example, the expanded field of view range reaches ±50°), this method can also be used for low-earth orbit satellites, and this embodiment does not limit the application scenarios of this method. As Figure 1 shown, the method includes:

[0080] Step 101, when the satellite needs to serve at least one target area simultaneously, obtain the first beam information of the satellite at the first running time and the second beam information at the second running time.

[0081] The target area refers to the surface area that the satellite is about to serve or is currently serving. Exemplarily, the satellite determines whether it needs to serve at least one target area simultaneously, including: determining whether the relative position relationship between the satellite and the target area satisfies the service position relationship based on the satellite's ephemeris information; if it satisfies, determine that the satellite needs to serve the target area simultaneously; if it does not satisfy, determine that the satellite stops serving the target area simultaneously.

[0082] Exemplarily, the service position relationship includes: the off-axis angle of the center of the target area relative to the satellite is within the first angle range, and the azimuth angle of the center of the target area relative to the satellite is within the second angle range. Among them, the off-axis angle refers to the angle between the line connecting the center of the target area and the satellite and the direction directly facing the satellite, and this off-axis angle is used to reflect the degree to which the center of the target area deviates from the position directly below the satellite. For example: referring to Figure 2 , the direction directly facing satellite 200 is the z-axis direction, and the z-axis direction points to the point on the earth's surface closest to satellite 200, then the off-axis angle of the center A of the target area relative to satellite 200 is θ. The azimuth angle refers to the horizontal direction angle of the center of the target area in the satellite's field of view, and the azimuth angle is used to determine the specific position of the center of the target area in the satellite's horizontal field of view. For example: referring to Figure 2 , the plane where the horizontal field of view of satellite 200 is located is the plane formed by xoy, then the angle formed by the line connecting the projection point A' of the center of the target area in the xoy plane and satellite 200 and the x-axis is the azimuth angle

[0083] In this embodiment, taking the service position relationship set based on the off-axis angle and azimuth angle as an example for illustration, in other embodiments, the service position relationship can also be set based on other parameters. For example, it can be set based on the azimuth angle and elevation angle. This embodiment does not limit the setting method of the service position relationship.

[0084] The ephemeris information of the satellite is used to calculate the specific spatial coordinates of the satellite at any running time. This running time (including the current running time, the first running time, and the second running time in the following text) is the absolute time of the satellite's on-orbit operation. Different satellites in the same orbit have a globally synchronized time-frequency reference, so they have a synchronized and updated running time. Exemplarily, the ephemeris information of the satellite includes the satellite's orbit parameters and the satellite position. Among them, the orbit parameters are used to describe the running position, shape, and orientation of the satellite in space, and the satellite position is used to describe the specific spatial coordinates of the satellite at a certain historical running time. Correspondingly, the method for obtaining the relative position relationship between the satellite and the target area includes: determining the satellite position at the current running time based on the satellite's orbit parameters and the satellite position at the historical running time; obtaining the area position of the area center of each target area stored in advance; calculating the off-axis angle and azimuth angle of the area position relative to the satellite position to obtain the relative position relationship between the satellite and the target area at the current running time.

[0085] Optionally, each satellite can simultaneously provide services for at least two target areas. At this time, the beam coverage area of the satellite includes multiple wave positions within the same period of time. The wave positions correspond to the target areas one by one, and each target area includes multiple users to be served. The multiple users to be served in the same target area form a group of users. Therefore, there is also a one-to-one correspondence between the wave positions and the user groups. The satellite stores the one-to-one correspondence relationship between the wave positions and the user groups. Among them, the wave position corresponding to each target area refers to the position of the beam center of the beam used to cover the target area. For example: Refer to Figure 2 , satellite 200 can simultaneously provide services for 4 target areas. The beam coverage range of each wave position includes a group of users, which can be a ground base station or a user terminal, etc. Satellite 200 stores the one-to-one correspondence relationship between the user groups and the wave positions in the 4 target areas.

[0086] In the case where the satellite simultaneously provides services for at least two target areas, the satellite divides the time slots of the user groups corresponding to the beam pointing of each wave position according to the hopping beam strategy. The hopping beam strategy is used to periodically switch the beam pointing and dwell time to allocate limited satellite resources (such as power, frequency, time) to different user groups as needed.

[0087] Exemplarily, the satellite divides the time slots corresponding to the user groups pointed by the beam in each wave position according to the hopping beam strategy, including: dividing the operation time period during which the satellite provides services for at least two target areas into periodically repeated frames, each frame being divided into multiple time slots, and each time slot corresponding to the service time window of a user group, so as to cover the beam for the user group within the service time window. Wherein, the time length of each frame and the time length of each time slot can be set according to communication requirements, and this embodiment does not limit the values of the time length of each frame and the time length of each time slot.

[0088] In this embodiment, for the time slots where the user groups are located in each target area, as the satellite moves during the time slot, the position of the target area relative to the satellite changes in real time. For example: Refer to Figure 2 , for the regional center A of the target area, as the satellite moves during the time slot, the satellite 200 always moves along the satellite movement direction. At this time, the position of the target area relative to the satellite 200 changes in real time. Therefore, as the operation time progresses, the direction of the beam emitted by the satellite 200 to the target area also needs to change in real time.

[0089] Specifically, the first beam information and the second beam information include the wave position pointing information and beamforming parameters corresponding to each target area; the second operation time is after the first operation time and is separated from the first operation time by a preset time period, and the preset time period is less than the time length of the time slot for covering the beam in the target area. For each set of the first beam information and the second beam information, since they include the wave position pointing information and beamforming parameters at different operation times, the wave position pointing information in the first beam information is different from the wave position pointing information in the second beam information, and the beamforming parameters in the first beam information are different from the beamforming parameters in the second beam information.

[0090] In one example, obtaining the first beam information of the satellite at the first operation time and the second beam information at the second operation time includes the following steps:

[0091] Step 1, for each target area, obtain the beamforming matrix to be updated currently in the target area and the channel transmission matrix corresponding to the wave position pointing information of the target area at the target operation time.

[0092] Wherein, when the target operation time is the first operation time, the wave position pointing information is the wave position pointing information in the first beam information; when the target operation time is the second operation time, the wave position pointing information is the wave position pointing information in the second beam information.

[0093] Initialize the parameters in the beamforming matrix to be updated as randomly generated or default settings. This embodiment does not limit the acquisition method of the beamforming matrix to be updated. The beamforming matrix to be updated will be iteratively updated and optimized later. Therefore, this embodiment does not require the accuracy of the initialized beamforming matrix to be updated.

[0094] Obtain the channel transmission matrix corresponding to the wave position pointing information of the target area at the target operation time, including: based on the satellite ephemeris information and the target operation time (the first operation time or the second operation time), determine the off-axis angle and azimuth angle of the target area relative to the satellite to obtain the wave position pointing information at the target operation time; obtain the channel transmission matrix related to the wave position pointing information based on the pre-created channel model.

[0095] As can be seen from the above, the satellite ephemeris information includes the satellite's orbital parameters and the satellite positions at historical operation times. Therefore, based on the orbital parameters and satellite positions, the satellite position corresponding to the target operation time can be determined. Then, based on the regional position of the target area stored in the satellite and the satellite position corresponding to the target operation time, the off-axis angle and azimuth angle of the target area relative to the satellite at the target operation time can be determined, thereby obtaining the wave position pointing information at the target operation time.

[0096] The channel model is used to simulate the channel characteristics of the transmission channel between the satellite and the user group. For example, it includes path loss characteristics, attenuation characteristics, and multipath effect characteristics, etc. The channel model includes various model parameters, and at least one model parameter is related to the wave position pointing information. For example, the transmit antenna gain and receive antenna gain are related to the wave position pointing information. Based on the wave position pointing information and the channel model, the channel transmission matrix related to the wave position pointing information can be determined.

[0097] Step 2, based on the beamforming matrix to be updated and the channel transmission matrix, determine the minimum mean square error receiver of the target area.

[0098] In this application, for the phased array feed reflector antenna that has been set up, the beamforming problem can be modeled as the maximum user combined rate problem, that is, to maximize the sum of the channel capacities of the user groups in all target areas. This problem can be expressed as follows:

[0099]

[0100] Where K represents the total number of target areas (i.e., user groups); F k represents the beamforming matrix to be updated for target area k; F i represents the beamforming matrix to be updated for target area i; i is a positive integer that takes values from 1 to K in sequence but not equal to k, and k represents any integer from 1 to K; H kDenote the channel transmission matrix corresponding to the wave position pointing information of the target area k at the target running time. R represents the illumination matrix, which is fixed after the position of the phased array feed reflector antenna is given. The elements in the illumination matrix R where i is the index of the reflector element, and j is the index of the phased array feed element; the amplitude term r ij = cos q (Ω ij ), corresponding to the radiation pattern of the feed, and Ω ij represents the angle (i.e., the off-axis angle) of the i-th reflector element relative to the z-axis of the j-th phased array element; q is a preset system parameter, and the value of q is related to the structure of the phased array feed. The phase term θ ij = 2πL ij / λ, where L is the distance from the corresponding phased array feed to the reflector, λ is the wavelength at the antenna operating frequency, and L ij represents the distance between the i-th reflector element and the j-th phased array feed element. I represents the identity matrix; σ 2 represents the noise power; the superscript H represents the conjugate transpose of the matrix; det(·) represents the determinant value of the matrix in the parentheses. α k represents the priority weight of the target area k; R k represents the channel capacity of the target area k.

[0101] Exemplarily, the constraint of the maximum user sum rate problem is the power constraint condition, that is, the antenna radiation power cannot exceed the maximum power. In other words, under the constraint of the power constraint condition, it is necessary to continuously update the beamforming matrix of the target area k to maximize the user sum rate. This power constraint condition can be expressed by the following formula:

[0102]

[0103] where P max represents the preset maximum power; F k represents the updated beamforming matrix of the target area k; k represents any integer from 1 to K; K represents the total number of target areas; R represents the illumination matrix; Tr(·) represents the trace of the matrix; the superscript H represents the conjugate transpose of the matrix.

[0104] Since the weighted sum rate problem is a non-convex optimization problem that is difficult to solve, and the weighted minimum mean square error (MMSE) problem is equivalent to the weighted sum rate problem under specific conditions and the weighted MMSE can be solved by iterative convex optimization; therefore, in this embodiment, the weighted sum rate problem is converted into a weighted minimum mean square error problem by introducing a weighted matrix.

[0105] Specifically, according to the principle of the MMSE receiver, for the target area k, the received signal y of the satellite k can be expressed as:

[0106]

[0107] where s k represents the transmitted signal of the user in the target area k, and s i represents the transmitted signal of the user in the target area i; H k represents the channel transmission matrix corresponding to the wave position pointing information of the target area k at the target operation time; F k represents the beamforming matrix to be updated for the target area k; F i represents the beamforming matrix to be updated for the target area i; i is a positive integer that takes values from 1 to K in sequence but is not k; n k represents the transmission noise of the user in the target area k, I represents the identity matrix; σ 2 represents the noise power.

[0108] The MMSE receiver A k aims to estimate s k such that the mean square error (MSE) E k is minimized, that is, to minimize the value of the following formula:

[0109]

[0110] Substituting y k and the transmission noise into the expression of E k , we get:

[0111]

[0112] Taking the derivative of A k and setting the derivative to zero, we obtain the minimum mean square error receiver for the target area k expressed by the following formula:

[0113]

[0114] B i = RF i ;

[0115] where, represents the minimum mean square error MMSE receiver for the target area k; F k represents the beamforming matrix to be updated for the target area k; F i represents the beamforming matrix to be updated for the target area i; i is a positive integer that takes values from 1 to K in sequence, and k represents any integer from 1 to K; K represents the total number of target areas; Hk Denote the channel transmission matrix corresponding to the wave position pointing information of the target area k at the target running time as \(H\); \(R\) represents the illumination matrix; \(I\) represents the identity matrix; \(\sigma\) represents the noise power; the superscript \(H\) represents the conjugate transpose of the matrix.

[0116] At this time, substitute the beamforming matrix \(F\) to be updated obtained in step 1 k and \(F\) i , and the channel transmission matrix \(H\) k into the expression of, and the minimum mean square error receiver of the target area k can be obtained.

[0117] Step 3, determine the weighting matrix based on the minimum mean square error receiver and the priority weight of the target area.

[0118] Substitute into the expression of \(E\) k to get

[0119]

[0120] \(B\) k \(= RF\) k ;

[0121] \(B\) i \(= RF\) i .

[0122] Let and the Woodbury identity indicates that:

[0123] \((A + UCV)\) -1 \(= A\) -1 \(- A\) -1 \(U(C\) -1 \(+ VA\) -1 \(U)\) -1 \(VA\) -1 ;

[0124] Let \(A = R\) kk , \(U = H\) k \(B\) k , \(C = I\), According to the above Woodbury identity, we can get:

[0125]

[0126] The expression of can be represented as:

[0127]

[0128] Substitute into to get:

[0129]

[0130] Simplifying this equation gives:

[0131]

[0132] From Woodbury's identity, we know that log2detR k represents the channel capacity of the target region k, which shows that there is a formal relationship between the sum rate and the MSE matrix.

[0133] Furthermore, the above maximum user sum rate problem f(F) can also be expressed as:

[0134]

[0135] The weighted MMSE problem g(F) can be expressed as:

[0136]

[0137] where W k represents the weighting matrix.

[0138] Taking the derivatives of the above f(F) and g(F) with respect to the beamforming matrix F k to be updated, we can obtain the gradients:

[0139]

[0140]

[0141] where According to the above gradient expressions, when the weighting matrix the Karush-Kuhn-Tucker (KKT) conditions of the maximum user sum rate problem and the weighted MMSE problem can be satisfied simultaneously. Therefore, the mutual transformation between the maximum user sum rate problem and the weighted MMSE problem can be achieved. Among them, the KKT conditions are used to transform the original constrained optimization problem into an unconstrained system of equations problem by introducing Lagrange multipliers.

[0142] Therefore, the weighting matrix is expressed by the following formula:

[0143]

[0144] where represents the weighting matrix of the target region k; α k represents the priority weight of the target region k; E kRepresents the mean square error of the target area k.

[0145] Substitute the minimum mean square error receiver determined in step 2 and the priority weight of the target area into the expression of the weighted matrix to obtain the weighted matrix.

[0146] Step 4, update the beamforming matrix to be updated based on the updated weighted matrix to obtain the updated beamforming matrix.

[0147] Construct a Lagrangian function by combining the Lagrange multiplier method with the power constraint As follows:

[0148]

[0149]

[0150] For the Lagrangian function Take the derivative with respect to the beamforming matrix F to be updated k to obtain the updated beamforming matrix F k ’, which is represented by the following formula:

[0151]

[0152] where F k ’ represents the updated beamforming matrix of the target area k; represents the minimum mean square error MMSE receiver of the target area i; represents the weighted matrix of the target area i; Tr(·) represents the trace of the matrix; P = P max , P max represents the preset maximum power.

[0153] Step 5, normalize the updated beamforming matrix so that the updated beamforming matrix satisfies the preset power constraint condition.

[0154] In one example, normalizing the updated beamforming matrix so that the updated beamforming matrix satisfies the preset power constraint condition includes:

[0155] Determine the current total power corresponding to the updated beamforming matrix; if the current total power is less than or equal to the maximum power, use the updated beamforming matrix as the normalized beamforming matrix and execute step 6; if the current total power is greater than the maximum power, determine the scaling factor of the updated beamforming matrix based on the ratio of the maximum power to the current total power, and scale the updated beamforming matrix using this scaling factor to obtain the normalized beamforming matrix, and execute step 6.

[0156] Exemplarily, the current total power P corresponding to the updated beamforming matrix current can be expressed by the following formula:

[0157]

[0158] The scaling factor α can be expressed by the following formula:

[0159]

[0160] where P max represents the maximum power.

[0161] Step 6, determine whether the normalized beamforming matrix meets the preset convergence condition. If it meets the convergence condition, execute Step 7; if it does not meet the convergence condition, execute Step 8.

[0162] In one example, determining whether the normalized beamforming matrix meets the preset convergence condition includes: determining whether the change amount between the combined rate corresponding to the beamforming matrix after this normalization and the combined rate corresponding to the beamforming matrix after the last normalization is less than or equal to the preset change amount threshold; if the change amount is less than or equal to the preset change amount threshold, determine whether the normalized beamforming matrix meets the preset convergence condition; if the change amount is greater than the preset change amount threshold, determine that the normalized beamforming matrix does not meet the preset convergence condition.

[0163] Step 7, if the convergence condition is met, determine the normalized beamforming matrix as the beamforming parameter corresponding to the wave position pointing information.

[0164] Among them, when the wave position pointing information is the wave position pointing information in the first beam information, the beamforming parameter is the beamforming parameter corresponding to the wave position pointing information in the first beam information; when the wave position pointing information is the wave position pointing information in the second beam information, the beamforming parameter is the beamforming parameter corresponding to the wave position pointing information in the second beam information. Thus, the first beam information corresponding to the first running time and the second beam information corresponding to the second running time can be obtained.

[0165] Reference Figure 3 , according to the acquisition process of the first beam information and the second beam information, it can be known that each satellite includes an ephemeris monitoring module and a parameter storage module. The ephemeris monitoring module is used to obtain satellite position, orbital parameters, and regional position; based on the parameters obtained by the ephemeris monitoring module, generate the first beam information corresponding to the first running time (i.e., the effective time parameter) and the second beam information corresponding to the second running time (i.e., the effective time parameter) in the parameter storage module. Both the first beam information and the second beam information include wave position pointing information and beamforming parameters.

[0166] Step 8, if the convergence condition is not satisfied, then use the normalized beamforming matrix as the beamforming matrix to be updated, and trigger the execution of the steps of determining the minimum mean square error receiver of the target area based on the beamforming matrix to be updated and the channel transmission matrix and the subsequent steps, that is, trigger the execution of Step 2.

[0167] After the satellite calculates a set of first beam information and second beam information, it stores the set of first beam information and second beam information for use in subsequent beam adjustments.

[0168] To more clearly understand the process of obtaining the beamforming parameters corresponding to the wave position pointing information, refer to Figure 4 , according to Figure 4 It can be seen that in this embodiment, first, the problem of maximizing the user sum rate By introducing the weighting matrix W, it is transformed into the problem of minimizing the mean square error max W,A,F Tr(W k E k (A k , F k ))), solve the minimum mean square error receiver A based on the problem of minimizing the mean square error, update the problem of minimizing the mean square error based on the minimum mean square error receiver A, and obtain max W,F Tr(W k E k (A k opt , F k ))), determine the weighting matrix W based on the updated problem of minimizing the mean square error, update the problem of minimizing the mean square error based on the determined weighting matrix W, and obtain max F Tr(W k opt E k (A k opt , F k ))), determine whether the current problem of minimizing the mean square error satisfies the convergence condition; if so, output the beamforming matrix F; if not, return to the step of "solving the minimum mean square error receiver A based on the problem of minimizing the mean square error", and perform iterative loop until the current problem of minimizing the mean square error satisfies the convergence condition, and output the beamforming matrix F.

[0169] Step 102, for each target area, when the current running time of the satellite is between the first running time and the second running time, determine the angle information of the target area relative to the satellite based on the ephemeris information at the current running time and the regional position of the target area.

[0170] The ephemeris information of the current running time includes the orbital parameters of the satellite and the satellite positions at historical running times before the current running time. Based on the orbital parameters and the satellite positions, the satellite position corresponding to the current running time can be determined. Based on the regional position of the target area stored in the satellite and the satellite position corresponding to the target running time, the off-axis angle and azimuth angle of the target area relative to the satellite at the target running time can be determined, thereby obtaining the angle information of the target area relative to the satellite.

[0171] When the current running time of the satellite is greater than or equal to the second running time, update the second running time to the first running time, and trigger the execution of the steps of obtaining the first beam information of the satellite at the first running time and the second beam information at the second running time and subsequent steps, that is, return to step 101.

[0172] Step 103, determine the target wave position pointing information in the first beam information that best matches the angle information.

[0173] Exemplarily, the wave position pointing information in the first beam information includes the off-axis angle and azimuth angle of the target area relative to the satellite at the first running time; the angle information includes the off-axis angle and azimuth angle of the target area relative to the satellite at the current running time. Accordingly,

[0174] Determining the target wave position pointing information in the first beam information that best matches the angle information includes:

[0175] Among at least two pieces of wave position pointing information in the first beam information, determine a piece of wave position pointing information with the smallest difference in off-axis angle from the off-axis angle in the angle information and the smallest difference in azimuth angle from the azimuth angle in the angle information. This wave position pointing information is the target wave position pointing information.

[0176] Step 104, perform linear interpolation on the beamforming parameters indicated by the target wave position pointing information in the first beam information and the second beam information to obtain the beamforming parameters of the target area.

[0177] In one example, the same set of first beam information and second beam information for the same target area are correlated with each other. For example: the same set of first beam information and second beam information for the same target area are associated based on the same beam index; accordingly,

[0178] Performing linear interpolation on the beamforming parameters indicated by the target wave position pointing information in the first beam information and the second beam information to obtain the beamforming parameters of the target area includes:

[0179] Determine the first beamforming parameter corresponding to the target wave position pointing information in the first beam information; obtain the beam index of the first beam information; determine the second beamforming parameter in the second beam information associated with the beam index; perform linear interpolation on the first beamforming parameter and the second beamforming parameter to obtain the beamforming parameter of the target area.

[0180] For example: The first running time is 2025-04-03 10:05, and the preset duration between the first running time and the second running time is 15 minutes, then the second running time is 2025-04-03 10:20; at this time, the first beam information at 2025-04-03 10:05 and the second beam information at 2025-04-03 10:20 are the same set of first beam information and second beam information. The same set of first beam information and second beam information for target area A can be associated through index 1, and the same set of first beam information and second beam information for target area B can be associated through index 2. At this time, after the satellite determines the first beamforming parameter in the first beam information according to the target wave position pointing information, it can associate the second beam information according to the index (1 or 2) of the first beam information, so as to obtain the second beamforming parameter in the second beam information.

[0181] Exemplarily, performing linear interpolation on the first beamforming parameter and the second beamforming parameter to obtain the beamforming parameter of the target area is represented by the following formula:

[0182] F″ = F0 + α(F1 - F0);

[0183] α = (t″ - t) / (t′ - t);

[0184] Wherein, F″ represents the beamforming parameter of the target area; F0 represents the first beamforming parameter; F1 represents the second beamforming parameter; α represents the update factor; t″ represents the current running time; t′ represents the second running time; t represents the first running time.

[0185] Step 105, control the phased array feed reflector antenna to generate a beam for the target area according to the beamforming parameter to provide services for the target area.

[0186] For each target area, the beamforming matrix F″ corresponding to the target area at the current running time includes N matrix elements F″ n , F″ n represents the weighting coefficient of the nth element in the phased array feed, Wherein, a n represents the amplitude of the weighting coefficient of the nth element, φ nRepresents the phase in the weighting coefficient of the nth array element, where n is a positive integer from 1 to N, and N represents the number of array elements in the phased array feed. Exemplarily, controlling the phased array feed reflector antenna to generate a beam for the target area according to the beamforming parameters includes: adjusting the phase and power of each array element according to the determined beamforming matrix F″ through the control module (such as a phase shifter and a power amplifier) of each array element in the phased array feed reflector antenna, and generating a beam for the target area at the current operating time.

[0187] In summary, the beamforming method based on the phased array feed reflector antenna provided in this embodiment obtains the first beam information of the satellite at the first operating time and the second beam information at the second operating time when the satellite needs to serve at least one target area simultaneously; wherein, the first beam information and the second beam information include the wave position pointing information and beamforming parameters corresponding to each target area; for each target area, when the current operating time of the satellite is between the first operating time and the second operating time, based on the ephemeris information at the current operating time and the regional position of the target area, determine the angular information of the target area relative to the satellite; determine the target wave position pointing information in the first beam information that best matches the angular information; perform linear interpolation on the beamforming parameters indicated by the target wave position pointing information in the first beam information and the second beam information to obtain the beamforming parameters of the target area; control the phased array feed reflector antenna to generate a beam for the target area according to the beamforming parameters to provide services for the target area; provides a beamforming method based on the phased array feed reflector antenna, which can integrate the advantages of flexible control of the phased array antenna beam and high gain of the reflector antenna, improve the beamforming and switching capabilities of the large-aperture reflector antenna, enable the medium and high-orbit satellite to have the ability of flexible beam switching and on-demand staring for ground terminals, provides a feasible solution for the application of medium and high-orbit satellites in the low-frequency band (such as the 1-2 GHz band), and enables the medium and high-orbit satellite to provide direct connection services for ground terminal users on demand.

[0188] Based on the above embodiment, the satellite updates the beamforming parameters every preset adjustment duration. Correspondingly, after controlling the phased array feed reflector antenna to generate a beam for the target area, that is, after step 105, the following steps are further included:

[0189] Determine whether to continue serving at least one target area;

[0190] In the case of determining to continue serving, if the current operating time of the satellite is between the first operating time and the second operating time, trigger the execution of the step of determining the angular information of the target area relative to the satellite based on the ephemeris information at the current operating time and the regional position of the target area and the subsequent steps, that is, return to step 102;

[0191] When the current running time of the satellite is greater than or equal to the second running time, replace the first running time with the second running time, replace the second running time with the first running time plus a preset duration, and trigger the execution of the steps of obtaining the first beam information of the satellite at the first running time and the second beam information at the second running time, and then return to step 101;

[0192] When it is determined to stop the service, send the regional positions of at least one target area to the next satellite, so that the next satellite can obtain the first beam information at the first running time and the second beam information at the second running time, and generate beamforming parameters for the target area based on the regional positions.

[0193] Since satellites in the same orbit have a globally synchronized time-frequency reference, the regional positions between the next satellite and the current satellite can be directly migrated, enabling seamless switching for users in the target area when switching satellites.

[0194] After the next satellite obtains the regional positions, it generates the first beam information and the second beam information based on the same process as steps 101-105, and then generates beamforming parameters.

[0195] Optionally, the satellite determines every preset adjustment duration whether to continue to serve at least one target area, and this preset adjustment duration is less than the preset duration. For the relevant description of determining whether to continue to serve at least one target area, refer to the description of whether to serve at least one target area simultaneously in step 101, which will not be elaborated in this embodiment.

[0196] To more clearly understand the beamforming method provided in this application, taking the example that each satellite serves multiple target areas simultaneously, an example is given from the moment when the satellite is about to serve these multiple target areas simultaneously to the moment when the next satellite is about to serve these multiple target areas simultaneously. Refer to Figure 5 , the method includes the following steps:

[0197] Step 501, the satellite determines whether it needs to serve at least one target area simultaneously; if so, execute step 502; if not, execute step 501 again after the preset adjustment duration;

[0198] Step 502, taking the current running time as the first running time and the first running time plus the preset duration as the second running time, generate the first beam information at the first running time and the second beam information at the second running time based on the regional positions of each target area in the satellite ephemeris information.

[0199] The first beam information at the first running time can form an execution beamforming code table, specifically refer to Table 1 below; the second beam information at the second running time can form an updated beamforming code table, specifically refer to Table 2 below. Table 1 and Table 2 take the preset duration between the first running time and the second running time as 15 minutes as an example for illustration. In actual implementation, the preset duration can also be other values, and this embodiment does not limit the value of the preset duration. The execution beamforming code table includes the first running time 2025-04-03 10:05, the wave position pointing information and beamforming parameters of area positions A1 to A4; the updated beamforming code table includes the second running time 2025-04-03 10:20, the wave position pointing information and beamforming parameters of area positions A1 to A4.

[0200] Table 1:

[0201]

[0202] Table 2:

[0203]

[0204] Step 503, determine whether the current running time is greater than or equal to the first running time and less than the second running time; if so, determine that the current running time is between the first running time and the second running time, and execute Step 504; if not, replace the first running time with the second running time, replace the second running time with the first running time plus the preset duration, and execute "generate the first beam information at the first running time and the second beam information at the second running time based on the area positions of each target area in the satellite ephemeris information" in Step 502 again;

[0205] When the current running time is equal to the second running time or greater than the second running time, the satellite re-determines the first beam information and the second beam information. At this time, the execution beamforming code table is updated to Table 3 below, and the updated beamforming code table is updated to Table 4 below. At this time, the first running time is replaced with the original second running time 2025-04-03 10:20, the second running time is replaced with the first running time plus the preset duration, and the new second running time is 2025-04-03 10:35. At this time, the first beam information at the new first running time is the same as the second beam information at the original second running time.

[0206] Table 3:

[0207]

[0208] Table 4:

[0209]

[0210] Step 504: Determine the angular information of the target area relative to the satellite based on the ephemeris information at the current running time and the regional location of the target area.

[0211] Step 505: Determine the target wave position pointing information in the first beam information that best matches the angular information.

[0212] Step 506: Perform linear interpolation on the beamforming parameters indicated by the target wave position pointing information in the first beam information and the second beam information to obtain the beamforming parameters of the target area.

[0213] Step 507: Control the phased array feed reflector antenna to generate a beam for the target area according to the beamforming parameters to provide services for the target area.

[0214] Step 508: Determine whether to continue to serve at least one target area; if so, execute Step 503; if not, execute Step 509.

[0215] Step 509: Send the regional location of the target area to the next satellite for the next satellite to calculate and execute the beam switching code table and update the beam switching code table and perform beamforming to achieve seamless handover of service satellites.

[0216] Optionally, in actual implementation, the current satellite can also send other parameters to the next satellite, such as the first beam information and the second beam information corresponding to the first running time and the second running time closest to the current running time. This embodiment does not limit the content of the parameters sent by the current satellite to the next satellite.

[0217] In summary, the beamforming method provided in this embodiment can combine the advantages of flexible control of the phased array antenna beam and the high gain and low cost of the reflector antenna. By designing an adapted beamforming method and linearly interpolating the dual code tables of the execution beam switching code table and the updated beam switching code table to generate beamforming parameters with a specific pointing in real time, it enables medium and high orbit satellites to have the ability to flexibly switch beams to ground terminals and gaze on demand, providing a feasible solution for the low-frequency band application of medium and high orbit satellites.

[0218] Figure 6 The block diagram of a beamforming device based on a phased array feed reflector antenna according to an embodiment of the present disclosure is shown. The device includes: a parameter acquisition module 610, an angle determination module 620, a parameter matching module 630, a parameter generation module 640, and a beam generation module 650.

[0219] A parameter acquisition module 610, configured to obtain first beam information of the satellite at a first operating time and second beam information of the satellite at a second operating time when the satellite needs to serve at least one target area simultaneously; wherein, the first beam information and the second beam information include wave position pointing information and beamforming parameters corresponding to each target area; the second operating time is after the first operating time and is separated from the first operating time by a preset time period;

[0220] An angle determination module 620, configured to, for each target area, when the current operating time of the satellite is between the first operating time and the second operating time, determine angle information of the target area relative to the satellite based on ephemeris information at the current operating time and the regional position of the target area;

[0221] A parameter matching module 630, configured to determine target wave position pointing information in the first beam information that best matches the angle information;

[0222] A parameter generation module 640, configured to perform linear interpolation on beamforming parameters indicated by the target wave position pointing information in the first beam information and the second beam information to obtain beamforming parameters of the target area;

[0223] A beam generation module 650, configured to control the phased array feed reflector antenna to generate a beam for the target area according to the beamforming parameters to provide services for the target area.

[0224] In a possible implementation manner, after controlling the phased array feed reflector antenna to generate a beam for the target area according to the beamforming parameters, the apparatus further includes: a service detection module and a parameter sending module.

[0225] A service detection module, configured to determine whether to continue serving the at least one target area;

[0226] The angle determination module 620 is further configured to, when it is determined to continue serving, if the current operating time of the satellite is between the first operating time and the second operating time, trigger the execution of the step of determining angle information of the target area relative to the satellite based on ephemeris information at the current operating time and the regional position of the target area and subsequent steps;

[0227] The parameter acquisition module 610 is further configured to, when the current running time of the satellite is greater than or equal to the second running time, replace the first running time with the second running time, replace the second running time with the first running time plus a preset duration, and trigger the execution of the steps of acquiring the first beam information of the satellite at the first running time and the second beam information of the satellite at the second running time and the subsequent steps;

[0228] The parameter sending module is configured to, when it is determined to stop the service, send the regional positions of the at least one target region to the next satellite, so that the next satellite can acquire the first beam information of the satellite at the first running time and the second beam information of the satellite at the second running time, and generate beamforming parameters of the target region based on the regional positions.

[0229] In a possible implementation manner, the parameter acquisition module 610 is configured to:

[0230] For each target region, acquire the beamforming matrix to be updated currently in the target region and the channel transmission matrix corresponding to the wave position pointing information of the target region at the target running time; wherein, when the target running time is the first running time, the wave position pointing information is the wave position pointing information in the first beam information; when the target running time is the second running time, the wave position pointing information is the wave position pointing information in the second beam information;

[0231] Based on the beamforming matrix to be updated and the channel transmission matrix, determine the minimum mean square error receiver of the target region;

[0232] Based on the minimum mean square error receiver and the priority weight of the target region, determine the weighting matrix;

[0233] Based on the weighting matrix, update the beamforming matrix to be updated to obtain an updated beamforming matrix;

[0234] Normalize the updated beamforming matrix so that the updated beamforming matrix meets a preset power constraint condition;

[0235] Determine whether the normalized beamforming matrix meets a preset convergence condition;

[0236] If the convergence condition is satisfied, the normalized beamforming matrix is determined as the beamforming parameter corresponding to the wave position pointing information; wherein, when the wave position pointing information is the wave position pointing information in the first beam information, the beamforming parameter is the beamforming parameter corresponding to the wave position pointing information in the first beam information; when the wave position pointing information is the wave position pointing information in the second beam information, the beamforming parameter is the beamforming parameter corresponding to the wave position pointing information in the second beam information;

[0237] If the convergence condition is not satisfied, the normalized beamforming matrix is used as the beamforming matrix to be updated, and the steps of determining the minimum mean square error receiver of the target area based on the beamforming matrix to be updated and the channel transmission matrix and subsequent steps are triggered.

[0238] In a possible implementation manner, determining the minimum mean square error receiver of the target area based on the beamforming matrix to be updated and the channel transmission matrix is represented by the following formula:

[0239]

[0240] B i = RF i ;

[0241] Wherein, represents the minimum mean square error MMSE receiver of target area k; F k represents the beamforming matrix to be updated of target area k; F i represents the beamforming matrix to be updated of target area i; i is a positive integer taking values in sequence from 1 to K, k represents any integer from 1 to K; K represents the total number of target areas; H k represents the channel transmission matrix corresponding to the wave position pointing information of target area k at the target operation time; R represents the illumination matrix; I represents the identity matrix; σ 2 represents the noise power; the superscript H represents the conjugate transpose of the matrix;

[0242] Correspondingly, determining the weighted matrix based on the minimum mean square error receiver and the priority weight of the target area is represented by the following formula:

[0243]

[0244]

[0245]

[0246] Wherein, The weighted matrix representing the target area k; α k Represents the priority weight of the target area k; E k Represents the mean square error of the target area k;

[0247] Correspondingly, update the beamforming matrix to be updated based on the updated weighted matrix to obtain an updated beamforming matrix, which is represented by the following formula:

[0248]

[0249] where F k ’ represents the updated beamforming matrix of the target area k; Represents the minimum mean square error MMSE receiver of the target area i; Represents the weighted matrix of the target area i; Tr(·) represents the trace of the matrix; P = P max , P max Represents the preset maximum power.

[0250] In a possible implementation, the power constraint condition is represented by the following formula:

[0251]

[0252] where P max Represents the preset maximum power; F k Represents the updated beamforming matrix of the target area k; k represents any integer from 1 to K; K represents the total number of target areas; R represents the illumination matrix; Tr(·) represents the trace of the matrix; the superscript H represents the conjugate transpose of the matrix.

[0253] In a possible implementation, the same set of first beam information and the second beam information of the same target area are associated based on the same beam index; correspondingly,

[0254] The parameter generation module 640 is used for:

[0255] Determine the first beamforming parameter corresponding to the target wave position pointing information in the first beam information;

[0256] Obtain the beam index of the first beam information;

[0257] Determine the second beamforming parameter in the second beam information associated with the beam index;

[0258] Perform linear interpolation on the first beamforming parameter and the second beamforming parameter to obtain the beamforming parameter of the target area.

[0259] In a possible implementation, linear interpolation is performed on the first beamforming parameter and the second beamforming parameter to obtain the beamforming parameter of the target area, which is represented by the following formula:

[0260] F″ = F0 + α(F1 - F0);

[0261] α = (t″ - t) / (t′ - t);

[0262] wherein, F″ represents the beamforming parameter of the target area; F0 represents the first beamforming parameter; F1 represents the second beamforming parameter; α represents the update factor; t″ represents the current running time; t′ represents the second running time; and t represents the first running time.

[0263] For relevant details, refer to the above method embodiments.

[0264] In some embodiments, the functions or modules included in the device provided in the embodiments of the present disclosure can be used to execute the methods described in the above method embodiments. The specific implementation can refer to the description of the above method embodiments. For the sake of brevity, it will not be repeated here.

[0265] The embodiments of the present disclosure further provide a beamforming device based on a phased array feed reflector antenna, including a memory, a processor, and a computer program stored on the memory. The processor executes the computer program to implement the steps of the above method.

[0266] The embodiments of the present disclosure further provide a non-volatile computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above method are implemented.

[0267] The embodiments of the present disclosure further provide a computer program product, including a computer program, or a non-volatile computer-readable storage medium carrying the computer program. When the computer program is executed by a processor, the steps of the above method are implemented.

[0268] Figure 7 FIG. 28 is a block diagram of a beamforming device 1900 based on a phased array feed reflector antenna shown according to an exemplary embodiment. For example, the device 1900 can be provided as a satellite. Refer to Figure 7 , the device 1900 includes a processing component 1922, which further includes one or more processors, and a memory resource represented by the memory 1932 for storing instructions executable by the processing component 1922, such as application programs. The application programs stored in the memory 1932 can include one or more modules corresponding to a set of instructions each. In addition, the processing component 1922 is configured to execute instructions to perform the above method.

[0269] Device 1900 may also include a power supply component 1926 configured to perform power management of device 1900, a wired or wireless network interface 1950 configured to connect device 1900 to a network, and an input / output interface 1958 (I / O interface). Device 1900 may operate based on an operating system stored in memory 1932, such as SpaceOS or the like.

[0270] In an exemplary embodiment, a non-volatile computer-readable storage medium is also provided, such as memory 1932 including computer program instructions, and the computer program instructions can be executed by a processing component 1922 of device 1900 to complete the above method.

[0271] The flowcharts and block diagrams in the figures illustrate the possible architectures, functions, and operations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagram may represent a module, a segment of a program, or a part of an instruction, and the module, segment of a program, or part of an instruction contains one or more executable instructions for implementing the specified logical function. In some alternative implementations, the functions noted in the blocks may occur in a different order than noted in the figures. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, and combinations of blocks in the block diagram and / or flowchart, can be implemented by a dedicated hardware-based system that performs the specified functions or actions, or can be implemented by a combination of dedicated hardware and computer instructions.

[0272] The various embodiments of the present disclosure have been described above. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, the practical application, or the improvement of the technology in the market, or to enable other ordinary skilled persons in the technical field to understand the embodiments disclosed herein.

Claims

1. A beamforming method based on a phased array feed reflector antenna, characterized in that: The method comprises: In the case where the satellite needs to serve at least one target area at the same time, first beam information of the satellite at a first operating time and second beam information at a second operating time are obtained; wherein the first beam information and the second beam information include beam position pointing information and beamforming parameters corresponding to each target area; the second operating time is located after the first operating time and is separated from the first operating time by a preset time length; For each target area, when the current operating time of the satellite is between the first operating time and the second operating time, determining angle information of the target area relative to the satellite based on the ephemeris information of the current operating time and the regional position of the target area; Determine the target beam position pointing information that best matches the angle information in the first beam information; Performing linear interpolation on the beamforming parameters indicated by the target beam position pointing information in the first beam information and the second beam information to obtain the beamforming parameters of the target area; The phased array feed reflector antenna is controlled to generate a beam of the target area according to the beamforming parameters to provide service to the target area.

2. The method according to claim 1, characterized in that After controlling the phased array feed reflector antenna to generate a beam of the target area according to the beamforming parameters, the method further includes: determining whether to continue serving the at least one target area; In the case of determining to continue the service, if the current operating time of the satellite is between the first operating time and the second operating time, triggering the step of determining the angle information of the target area relative to the satellite based on the ephemeris information of the current operating time and the regional position of the target area and subsequent steps; In a case where the current operating time of the satellite is greater than or equal to the second operating time, the first operating time is replaced by the second operating time, the second operating time is replaced by the first operating time plus a preset duration, and the step of acquiring the first beam information of the satellite at the first operating time and the second beam information at the second operating time and subsequent steps are triggered; When it is determined that the service is stopped, the regional position of the at least one target area is sent to the next satellite, so that the next satellite can obtain the first beam information at the first operating time and the second beam information at the second operating time, and generate the beamforming parameters of the target area based on the regional position.

3. The method according to claim 1 or 2, characterized in that: The obtaining of first beam information of the satellite at a first operating time and second beam information of the satellite at a second operating time includes: For each target area, obtain the beamforming matrix to be updated for the target area and the channel transmission matrix corresponding to the wave position pointing information of the target area at the target operation time; wherein, when the target operation time is the first operation time, the wave position pointing information is the wave position pointing information in the first beam information; when the target operation time is the second operation time, the wave position pointing information is the wave position pointing information in the second beam information; Determining a minimum mean square error receiver of the target area based on the beamforming matrix to be updated and the channel transmission matrix; Determining a weighting matrix based on the minimum mean square error receiver and the priority weights of the target area; Updating the to-be-updated beamforming matrix based on the weighting matrix to obtain an updated beamforming matrix; Normalizing the updated beamforming matrix so that the updated beamforming matrix satisfies a preset power constraint condition; Determining whether the normalized beamforming matrix meets a preset convergence condition; If the convergence condition is met, the normalized beamforming matrix is ​​determined as the beamforming parameter corresponding to the waveposition pointing information; wherein, when the waveposition pointing information is the waveposition pointing information in the first beam information, the beamforming parameter is the beamforming parameter corresponding to the waveposition pointing information in the first beam information; when the waveposition pointing information is the waveposition pointing information in the second beam information, the beamforming parameter is the beamforming parameter corresponding to the waveposition pointing information in the second beam information; If the convergence condition is not met, the normalized beamforming matrix is ​​used as the beamforming matrix to be updated, triggering the step of determining the minimum mean square error receiver of the target area based on the beamforming matrix to be updated and the channel transmission matrix and subsequent steps.

4. The method according to claim 3, characterized in that The minimum mean square error receiver of the target area is determined based on the beamforming matrix to be updated and the channel transmission matrix, which is expressed by the following formula: B i =RF i ; in, represents the minimum mean square error MMSE receiver of the target area k; F k represents the beamforming matrix to be updated for the target area k; F i represents the beamforming matrix to be updated for target region i; i is a positive integer ranging from 1 to K, k represents any integer ranging from 1 to K; K represents the total number of target regions; H k represents the channel transmission matrix corresponding to the wave position pointing information of the target area k at the target operation time; R represents the illumination matrix; I represents the unit matrix; σ 2 represents the noise power; the superscript H represents the conjugate transpose of the matrix; Accordingly, the weighting matrix is ​​determined based on the minimum mean square error receiver and the priority weight of the target area, which is expressed by the following formula: in, represents the weighting matrix of the target area k; α k represents the priority weight of the target area k; E k represents the mean square error of the target area k; Accordingly, the to-be-updated beamforming matrix is ​​updated based on the updated weighting matrix to obtain an updated beamforming matrix, which is expressed by the following formula: Among them, F k ' represents the updated beamforming matrix of target area k; represents the minimum mean square error MMSE receiver of target area i; W i opt represents the weighting matrix of target region i; Tr(·) represents the trace of the matrix; P = P max , P max Indicates the preset maximum power.

5. The method according to claim 3, characterized in that: The power constraint is expressed by the following formula: Among them, P max Indicates the preset maximum power; F k represents the updated beamforming matrix of target region k; k represents any integer from 1 to K; K represents the total number of target regions; R represents the illumination matrix; Tr(·) represents the trace of the matrix; and the superscript H represents the conjugate transpose of the matrix.

6. The method according to claim 1, characterized in that The same group of first beam information and the second beam information of the same target area are associated based on the same beam index; accordingly, The linearly interpolating the beamforming parameters indicated by the target beam position pointing information in the first beam information and the second beam information to obtain the beamforming parameters of the target area includes: Determining a first beamforming parameter corresponding to the target beam position pointing information in the first beam information; Obtaining a beam index of the first beam information; Determining a second beamforming parameter in second beam information associated with the beam index; Linearly interpolate the first beamforming parameter and the second beamforming parameter to obtain the beamforming parameter of the target area.

7. The method according to claim 1, characterized in that Linearly interpolating the first beamforming parameter and the second beamforming parameter to obtain a beamforming parameter of the target area is expressed by the following formula: F″=F0+α(F1-F0); α = (t″-t) / (t′-t); Among them, F″ represents the beamforming parameters of the target area; F0 represents the first beamforming parameters; F1 represents the second beamforming parameters; ɑ represents the update factor; t″ represents the current running time; t′ represents the second running time; t represents the first running time.

8. A beamforming device based on a phased array feed reflector antenna, comprising a memory, a processor, and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the steps of the method according to any one of claims 1 to 7.

9. A non-volatile computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer program product, comprising a computer program, or a non-volatile computer-readable storage medium carrying a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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