A distributed beam allocation method and system for low-orbit communication constellation

Abstract

The present invention discloses a distributed beam allocation method and system for a low-orbit communication constellation, wherein the method comprises the following steps: S1. Distributed star cluster task distribution; forwarding the planned task through a distributed centerless star cluster architecture, and broadcasting the task in the star cluster by dynamically determining the satellite on duty; S2. Target area wave position division based on sinusoidal space; after receiving the task, a single satellite calculates the beam wave position number of the ground terminal based on the geographical location coordinates of the satellite and the ground terminal; S3. Single-satellite beam resource allocation based on beam hopping; time is divided into time slots based on the beam hopping method, and distributed low-orbit communication constellation beam allocation is realized through a resource allocation algorithm. The method and system can improve the system robustness, reduce the amount of calculation and increase the calculation speed.

Description

Technical Field

[0001] The present invention relates to the field of satellite mission planning and is used for distributed centerless communication constellation beam allocation, in particular to a low-orbit communication constellation distributed beam allocation method and system. Background Art

[0002] Satellite communication systems can meet people's communication needs well with their large capacity, low latency and high spectrum utilization. Currently, satellite mission planning mostly adopts a centralized model. The requirements for centralized main satellites are relatively high, usually with high computing power and communication capabilities. As long as the main satellite can ensure safe and reliable operation, its mission completion rate is relatively high. The disadvantage is that the load of the main satellite is too high. Once the main satellite is threatened, the loss will be huge. Therefore, from the perspective of reliability, distributed is higher than centralized. The existing beam allocation method mainly focuses on the allocation of beam resources of a single satellite, and does not fully utilize the advantages of multiple satellites. As a typical resource-constrained system, satellite communication has limited onboard payload and spectrum efficiency resources, which are key factors restricting its development. The distributed beam allocation method can take advantage of the resource advantages of multiple satellites and improve the throughput of the satellite system. Summary of the invention

[0003] In view of the problems existing in the prior art, the object of the present invention is to provide a distributed beam allocation method and system for a low-orbit communication constellation, which can improve robustness, reduce the amount of calculation and increase the calculation speed.

[0004] To achieve the above object, the present invention provides a distributed beam allocation method for a low-orbit communication constellation, the method comprising the following steps:

[0005] S1. Distributed constellation task distribution: forwarding planned tasks through a distributed and decentralized constellation architecture, and broadcasting tasks in the constellation by dynamically determining the satellites on duty;

[0006] S2. Division of the target area based on sinusoidal space: after receiving the mission, a single satellite calculates the beam position number of the ground terminal based on the geographic location coordinates of the satellite and the ground terminal;

[0007] S3. Single-satellite beam resource allocation based on beam hopping: Split time into time slots based on beam hopping, and realize distributed low-orbit communication constellation beam allocation through resource allocation algorithm.

[0008] Further, step S1 is specifically implemented as follows:

[0009] When communication support is needed for a certain area, the ground station plans the mission. Through the ground station, the mission command is sent to any currently communicable satellite A; satellite A forwards the mission command to the on-duty satellite B through the intersatellite link; after the on-duty satellite B obtains the mission command, it broadcasts the mission command to the entire constellation through broadcasting; thus, after the entire constellation receives the mission command, it can perform independent beam calculation based on its own information, thereby achieving communication support for the designated area.

[0010] Further, in step S1, when there is a node failure, the on-duty satellite is replaced, and the specific steps of node satellite on-duty interpretation are as follows:

[0011] S1.1 The ID of the initialized satellite on duty is stored in each satellite in advance;

[0012] S1.2 The satellite on duty broadcasts heartbeat data to the entire constellation every cycle;

[0013] S1.3 When each satellite fails to receive the heartbeat data of the current node satellite for three consecutive cycles, it switches to a new on-duty satellite ID stored inside the satellite according to the satellite ID increment strategy;

[0014] S1.4 The new satellite on duty resends heartbeat data to the entire constellation.

[0015] Further, step S2 is specifically implemented as follows:

[0016] The spherical coordinate system beam scanning space is projected onto the sinusoidal space to form an area, which is composed of the azimuth angle and elevation Determine that for each azimuth , the elevation angle has a range , the corresponding sinusoidal coordinates are ,according to , , the beam width in sinusoidal space is the sine of the elevation normal beam width, and the elevation scanning range and the normal beam width are known, so the number of beams arranged in the elevation direction can be calculated.

[0017] Furthermore, the beam position numbering method is adopted: the ground coverage area of ​​the phased array antenna is divided into The beam positions in each sector area are numbered.

[0018] Further, the number calculation process is:

[0019] S2.1 is first divided into corresponding large areas according to the quadrant where the wave position center is located;

[0020] S2.2 is then divided into corresponding layers according to the off-axis angle;

[0021] S2.3 finally divides the area into the only corresponding fan-shaped area based on the comparison of the azimuth angle and the altitude angle;

[0022] S2.4 Each sector is numbered in ascending or descending order of altitude or azimuth.

[0023] Furthermore, after the beam positions are divided into sector-shaped areas and numbered, when the numbers of the positions where the ground terminals are located are subsequently counted, the sector-shaped area where the ground terminals are located is first found, and then a traversal search is performed in the sector-shaped area to find the corresponding positions.

[0024] Further, step S3 is specifically implemented as follows:

[0025] For the areas covered by low-orbit satellites, a coverage method combining wide beams and spot beams is adopted. The wide beam is used as a signaling beam, responsible for the transmission of ground service signaling messages within the satellite coverage area; the spot beam is a service beam, which is accessed in the form of beam hopping.

[0026] Furthermore, the time is divided into time slots based on the beam hopping method, and the utilization efficiency of limited resources is improved through the resource allocation algorithm.

[0027] Furthermore, the coverage area of ​​each satellite of the communication constellation is defined as a cell, where is the satellite number; each cell has elliptical wave positions, of which only There is a ground terminal inside each wave position, corresponding to the coverage position of the satellite spot beam; each spot beam coverage area is defined as a unit ; When the number of satellite beams is less than the number of units When Beam hopping is performed in each unit; in the satellite beam hopping working mode, the satellite's point beams reuse the same frequency band through time division.

[0028] On the other hand, the present invention provides a low-orbit communication constellation distributed beam allocation system, the system is used to implement the low-orbit communication constellation distributed beam allocation method according to the present invention, the system comprises a satellite parameter configuration module, a beam allocation algorithm calculation module, and a beam allocation result display module; wherein:

[0029] The satellite parameter configuration module is used to set the parameter configuration of the low-orbit communication constellation, including the number of constellation satellites, the current satellite number, the simulation initial time, the six elements of the orbit, the number of beams, the narrow beam width, and / or the maximum off-axis angle of the narrow beam;

[0030] A ground scene configuration module, used to configure the configuration of ground terminal parameters, including the number of ground terminals, the longitude of the ground terminal, the latitude of the ground terminal, the height of the ground terminal, and / or the minimum elevation angle of the terminal;

[0031] The beam allocation algorithm calculation module controls the calculation of the distributed beam allocation method of the low-orbit communication constellation by receiving the parameters of the satellite parameter setting module, calculates the position and speed of the satellite in the J2000 system using the six orbital numbers, and finally obtains the beam allocation matrix according to the beam allocation algorithm;

[0032] The beam allocation result display module is used to display the beam allocation matrix received from the beam allocation algorithm calculation module, and finally visualize the beam coverage of different terminals on the interface.

[0033] The beneficial effects of the present invention are as follows:

[0034] 1. This method realizes distributed constellation beam planning and enhances the robustness of constellation mission forwarding by dynamically selecting on-duty satellites.

[0035] 2. This method divides the ground coverage area of ​​the phased array antenna into multiple sector areas with the sub-satellite point as the center, and numbers the beam wave positions in each sector area. The advantage of this numbering is that the logic is simple and clear, which can reduce the amount of calculation when calculating the wave position number of the ground terminal.

[0036] 3. In order to improve the calculation speed, the advantages and disadvantages of polling beam allocation and fixed time slot beam allocation are comprehensively considered, the beam allocation problem is simplified, and beam hopping selection is performed based on the principle of equality and non-discrimination. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a flow chart of the distributed beam allocation method for low-orbit communication constellation according to the present invention;

[0038] Figure 2 Schematic diagram of the on-duty interpretation strategy for each satellite according to the present invention;

[0039] Figure 3 A schematic diagram of sinusoidal spatial beam coverage according to the present invention;

[0040] Figure 4 A schematic diagram of the sector-shaped partitioning of the beam ground coverage area according to the present invention;

[0041] Figure 5 A schematic diagram of beam hopping according to the present invention;

[0042] Figure 6 This is an architecture diagram of a distributed beam allocation system for a low-orbit communication constellation according to the present invention. DETAILED DESCRIPTION

[0043] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0045] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] The following combination Figure 1-Figure 6 The specific embodiments of the present invention are described in detail. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0047] The present invention discloses a distributed beam allocation method for low-orbit communication constellations. Low-orbit satellites refer to satellites operating in low earth orbits, and their orbital altitudes are generally between 500 and 2000 kilometers. The implementation process of this method is as follows: Figure 1 As shown in the figure, firstly, the planned tasks are forwarded through the distributed and decentralized constellation architecture, and the tasks are broadcast in the constellation by dynamically determining the satellites on duty. Secondly, after receiving the tasks, a single satellite calculates the beam position number of the ground terminal based on the geographic location coordinates of the satellite and the ground terminal. Finally, the time is divided into time slots based on the beam hopping method. Through a reasonably optimized resource allocation algorithm, the distributed low-orbit communication constellation beam allocation is finally realized, achieving the technical effect of improving the robustness of the system. Specifically, as Figure 1 As shown, the distributed beam allocation method for low-orbit communication constellation according to the present invention includes the following steps:

[0048] S1. Distributed constellation-based task distribution: forwarding planned tasks through a distributed and decentralized constellation architecture, and broadcasting tasks in the constellation by dynamically determining the satellites on duty.

[0049] S2. Division of target area wave positions based on sinusoidal space; after receiving a mission, a single satellite calculates the beam wave position number where the ground terminal is located based on the geographic location coordinates of the satellite and the ground terminal.

[0050] S3. Single-satellite beam resource allocation based on beam hopping: Split time into time slots based on beam hopping, and realize distributed low-orbit communication constellation beam allocation through resource allocation algorithm.

[0051] Among them, in step S1, based on the distributed star cluster task distribution, the specific implementation is as follows:

[0052] When communication support is needed for a certain area, the ground station plans the mission. Through the ground station, the mission command is sent to any currently communicable satellite (satellite A). Satellite A forwards the mission command to the on-duty satellite (satellite B) through the intersatellite link. After the on-duty satellite B obtains the mission command, it broadcasts the mission command to the entire constellation. In this way, after the entire constellation receives the mission command, it can perform independent beam calculation based on its own information, thereby achieving communication support for the specified area.

[0053] The satellite on duty is not fixed but changes dynamically. When there is a node failure, the satellite on duty will be replaced. The interpretation scheme of the satellite on duty is as follows: Figure 2 As shown, the specific steps are as follows:

[0054] S1.1 The ID of the initialized satellite on duty is stored in each satellite in advance;

[0055] S1.2 The satellite on duty broadcasts heartbeat data to the entire constellation every period; for example, in a constellation according to a specific practical embodiment of the present invention, there are four satellites A, B, C, and D, of which satellite A is the satellite on duty, and satellite A broadcasts heartbeat data to the remaining satellites B, C, and D every period;

[0056] S1.3 When each satellite fails to receive the heartbeat data of the current node satellite for three consecutive cycles, the new on-duty satellite ID is switched and stored inside the satellite according to the satellite ID increment strategy; for example, when satellites B, C, and D fail to receive the heartbeat data of the current node satellite A for three consecutive cycles, it is considered that the on-duty satellite A has a fault, and the on-duty satellite is switched to satellite B;

[0057] S1.4 The new on-duty satellite resends heartbeat data to the entire constellation. After satellite B becomes the new on-duty satellite, satellite B broadcasts heartbeat data to the remaining satellites A, C, and D every cycle.

[0058] Step S2. The target area wave position division based on the sinusoidal space is specifically implemented as follows:

[0059] Sine space is a mathematical tool for studying the scanning arrangement and distribution characteristics of array antenna beams. When studying array antenna beam scanning in a spherical coordinate system, the beam will widen when the scanning angle deviates from the normal direction, and the relationship between the widening and the scanning angle is nonlinear. It is difficult to study beam arrangement and grating lobe distribution in a spherical coordinate system, so it is hoped to choose a convenient coordinate system. In the sinusoidal space, the antenna pattern does not change with the scanning angle, but shifts proportionally with the scanning angle. The sinusoidal space is the projection of the unit sphere on the array plane.

[0060] The unit circle is the theoretical maximum range of the beam scanning. In reality, the beam will not scan to ±90°. Instead, it will form an area by projecting the beam scanning space of the spherical coordinate system in actual engineering applications onto the sinusoidal space according to the characteristics of the antenna itself and the actual engineering needs. This area is composed of the azimuth angle and elevation Determine that for each azimuth , the elevation angle has a range , the corresponding sinusoidal coordinates are ,according to , , the beam width is a constant in the sinusoidal space, that is, the sine of the elevation normal beam width, and the elevation scanning range and the normal beam width are known, so the number of beams arranged in the elevation direction is:

[0061] (1)

[0062] Similarly, it can be proved that when the elevation angle is constant, the number of azimuth beam arrangements is:

[0063] (2)

[0064] Assuming that the azimuth coverage of the spherical coordinate system is ±45° and the elevation coverage is ±40°, and the azimuth angle is 2° and the elevation angle is 3°, the beam coverage and beam position arrangement results of the sinusoidal coordinate system are as follows: Figure 3 As shown, the horizontal and vertical axes represent the azimuth and elevation angles of the phased array antenna respectively. The outermost ellipse in the figure represents the boundary outline of the sinusoidal space beam coverage, and the small circle inside represents the wave position arrangement of the beam in the sinusoidal space.

[0065] In order to determine the parameters of the beam coverage ellipse, including the center point, semi-major axis, semi-minor axis and twist angle, when the twist angle of the coverage area is zero, the standard equation of the beam coverage ellipse is:

[0066] (3)

[0067] Convert the rectangular coordinate system into the polar coordinate system, that is, Substituting into formula (3) we get

[0068] (4)

[0069] in represents the polar diameter, Indicates the polar angle.

[0070] When the ellipse has a torsion angle, that is, ,in is the twist angle, substitute it into the above formula and simplify it to get the final curve equation of the elliptical area:

[0071] (5)

[0072] Next, each ellipse is numbered and a beam position numbering method is proposed: the ground coverage area of ​​the phased array antenna is divided into Sector-shaped areas, and number the beam positions in each sector-shaped area, such as Figure 4 As shown, A, B, C, and D represent the corresponding large areas divided according to the quadrant where the wave position center is located, and A01 to A08 represent the sector-shaped areas divided by the beam wave position.

[0073] The advantage of this numbering is that the logic is simple and clear, which can reduce the amount of calculation when calculating the wave position number of the ground terminal. The numbering calculation process is:

[0074] S2.1 First, divide the wave position into corresponding large areas (A, B, C, D) according to the quadrant where the wave position center is located;

[0075] S2.2 is then divided into corresponding layers (concentric sectors) according to the off-axis angle;

[0076] S2.3 finally divides the area into the only corresponding fan-shaped area based on the comparison of the azimuth angle and the altitude angle;

[0077] S2.4 Number each sector area according to the principle of increasing / decreasing altitude or azimuth, such as Figure 5 As shown in the figure, area A is divided into 8 sectors. The upper sectors are numbered A01 to A04 and the lower sectors are numbered A05 to A08 according to the principle of increasing. It is worth noting that it is allowed that a wave position is divided into multiple sectors without affecting the subsequent calculation of the wave position number of the ground terminal.

[0078] After the beam wave positions are divided into sector-shaped areas and numbered, when the wave position numbers of the ground terminals are subsequently counted, the sector-shaped area where the ground terminals are located can be found first, and then a traversal search is performed within the sector-shaped area to find the corresponding wave position. Multi-layer screening can greatly reduce the amount of calculation.

[0079] Step S3: Single-satellite beam resource allocation based on beam hopping, specifically implemented as follows:

[0080] For the areas covered by low-orbit satellites, a combination of wide beams and narrow beams is used. The wide beam is used as a signaling beam, responsible for the transmission of signaling messages such as ground service requests within the satellite coverage area, to manage service users within the system and meet their basic needs; the narrow beam is a service beam, which has the characteristics of high bandwidth and high speed, and is accessed in the form of beam hopping, relying on its dynamic and adjustable characteristics to dynamically meet the communication business volume needs of hot spots.

[0081] Based on the beam hopping method, time is divided into time slots, and the utilization efficiency of limited resources is improved through a reasonable and optimized resource allocation algorithm. Compared with the traditional fixed beam working mode, the throughput and delay performance of the satellite communication system can be improved.

[0082] The coverage area of ​​each satellite in the communication constellation is defined as a cell, where is the satellite number. elliptical wave positions, of which only There is a ground terminal inside each wave position, corresponding to the coverage position of the satellite spot beam. Define each spot beam coverage area as a unit When the number of satellite beams is less than the number of units When the narrow beam is required Beam hopping is performed in each unit.

[0083] In the satellite beam-hopping mode, the satellite's spot beams reuse the same frequency band through time division. Figure 5 The figure is a beam hopping diagram, where LEO satellite A represents a low-orbit satellite A with two modes: wide beam and narrow beam. The wide beam is responsible for information transmission, and the narrow beam is responsible for communication services. The beam allocation method will allocate beams according to the number of beams, the needs of communication terminals, and resource constraints. Satellite A dynamically adjusts the direction and position of the beam in the spatial domain to achieve beam hopping to meet the communication needs of different users. Satellite A has two narrow beams, and there are 9 beam positions in the beam coverage area. There are 5 beam positions with users, namely U11, U21, U31, U23, and U33. Beam hopping is used to meet the communication needs of all users. One beam of satellite A jumps from U21 to U11 to U31, and the other beam jumps from U23 to U33.

[0084] In order to improve the calculation speed and comprehensively consider the advantages and disadvantages of polling beam allocation and fixed time slot beam allocation, the beam allocation problem is simplified. It is assumed that the demand of all users is the same, and the following beam allocation process is given based on the principle of equality and non-discrimination.

[0085] S3.1 counts the beam numbers of the ground terminals and the number of terminals in the coverage area of ​​the beam, and covers all the beam positions containing ground terminals in the form of beam hopping;

[0086] S3.2 The spot beams are evenly divided in the wave positions with ground terminals. The length of time spent in a certain wave position is proportional to the number of terminals.

[0087] S3.3 Assume that the satellite has spot beams, each beam can support There are ground terminals communicating. At a certain moment, the number of wave positions of ground terminals is , the total number of ground terminals is , The number of terminals in each of the wave positions is , The total communication time after deducting the consumption of beam hopping process is , then the residence time at each wave position is ;

[0088] S3.4 Considering the same-frequency interference, ensure that the distance between two beams in the same frequency band reaches and above, among which is the beam radius;

[0089] S3.5 takes into account the specified communication rate and communication capacity requirements of a single area (which can be set externally), optimizes the beam allocation results, sets weights for areas with relatively high communication rate and communication capacity requirements, increases high priority, and gives priority to beam coverage of this area;

[0090] S3.6 performs beam resource allocation for each beam position, that is, calculates the two-dimensional matrix ,in ,correspond spot beams, ,correspond Wave position, Indicates the communication duration within, no. The spot beam is The dwell time at a wave position.

[0091] On the other hand, the present invention also provides a low-orbit communication constellation distributed beam allocation system, which is used to implement the low-orbit communication constellation distributed beam allocation method according to the present invention.

[0092] Distributed beam allocation system for low-orbit communication constellation Figure 6 As shown, it includes a satellite parameter configuration module, a beam allocation algorithm calculation module, and a beam allocation result display module.

[0093] The satellite parameter configuration module is mainly used to set the parameter configuration of the low-orbit communication constellation, such as the number of constellation satellites, the current satellite number, the initial simulation time, the six elements of the orbit, the number of beams, the narrow beam width, the maximum off-axis angle of the narrow beam, etc.

[0094] The ground scene configuration module is mainly used to configure the ground terminal parameters, such as the number of ground terminals, ground terminal longitude, ground terminal latitude, ground terminal altitude, terminal minimum elevation angle, etc.

[0095] The beam allocation algorithm calculation module controls the calculation of the distributed beam allocation method of the low-orbit communication constellation mentioned above by receiving the parameters of the satellite parameter setting module, calculates the position and speed of the satellite in the J2000 system using the six orbital numbers, and finally obtains the beam allocation matrix according to the beam allocation algorithm.

[0096] The beam allocation result display module is used to display the beam allocation matrix received from the beam allocation algorithm calculation module, and finally visualize the beam coverage of different terminals on the interface.

[0097] The technical highlights are as follows:

[0098] 1. This method constructs a distributed and decentralized data forwarding architecture to achieve the distribution of beam allocation tasks in the constellation.

[0099] 2. This method divides the ground coverage area of ​​the phased array antenna into multiple sector areas with the sub-satellite point as the center when numbering the beam positions, and numbers the beam positions in each sector area.

[0100] 3. This method uses a beam hopping method to divide time into time slots when allocating beam resources, and improves the utilization efficiency of limited resources through a reasonably optimized resource allocation algorithm.

[0101] Any process or method description in the flowchart of the present invention or described in other ways herein can be understood as a module, segment or part of a code including one or more executable instructions for implementing the steps of a specific logical function or process, which can be implemented in any computer-readable medium for use by an instruction execution system, device or equipment, and the computer-readable medium can be any medium containing storage, communication, propagation or transmission programs for use by execution systems, devices or equipment, including read-only memories, magnetic disks or optical disks, etc.

[0102] In the description of this specification, the description with reference to the terms "embodiment", "example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. In addition, those skilled in the art can combine or combine different embodiments or examples described in this specification and the features therein without causing any contradiction.

[0103] Although the above content has shown and described the embodiments of the present invention, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace, modify and other update operations on the above embodiments within the scope of the present invention.

Claims

1. A distributed beam allocation method for low-orbit communication constellation, characterized in that: The method comprises the following steps: S1. Distributed constellation task distribution: forwarding planned tasks through a distributed and decentralized constellation architecture, and broadcasting tasks in the constellation by dynamically determining the satellites on duty; S2. Division of the target area based on sinusoidal space: after receiving the mission, a single satellite calculates the beam position number of the ground terminal based on the geographic location coordinates of the satellite and the ground terminal; S3. Single-satellite beam resource allocation based on beam hopping: Split time into time slots based on beam hopping, and realize distributed low-orbit communication constellation beam allocation through resource allocation algorithm; In step S2, the beam position numbering method is: the ground coverage area of ​​the phased array antenna is divided into Sector-shaped areas, and number the beam positions in each sector-shaped area; The number calculation process is: S2.1 is first divided into corresponding large areas according to the quadrant where the wave position center is located; S2.2 is then divided into corresponding layers according to the off-axis angle; S2.3 finally divides the area into the only corresponding fan-shaped area based on the comparison of the azimuth angle and the altitude angle; S2.4 Each sector is numbered according to the increasing / decreasing principle of altitude or azimuth.

2. The distributed beam allocation method for low-orbit communication constellation according to claim 1, characterized in that: Step S1 is specifically implemented as follows: When communication support is needed for a certain area, the ground station plans the mission; through the ground station, it sends mission instructions to any current communication satellite A; satellite A forwards the mission instructions to the on-duty satellite B through the intersatellite link; after the on-duty satellite B obtains the mission instructions, it broadcasts the mission instructions to the entire constellation; thus, after the entire constellation receives the mission instructions, it realizes independent beam calculation based on its own information, thereby achieving communication support for the designated area.

3. The distributed beam allocation method for low-orbit communication constellation according to claim 2, characterized in that: In step S1, when there is a node failure, the on-duty satellite is replaced. The specific steps for node satellite on-duty interpretation are as follows: S1.1 The ID of the initialized satellite on duty is stored in each satellite in advance; S1.2 The satellite on duty broadcasts heartbeat data to the entire constellation every cycle; S1.3 When each satellite fails to receive the heartbeat data of the current node satellite for three consecutive cycles, it switches to a new on-duty satellite ID stored inside the satellite according to the satellite ID increment strategy; S1.4 The new satellite on duty resends heartbeat data to the entire constellation.

4. The distributed beam allocation method for low-orbit communication constellation according to claim 1, characterized in that: Step S2 is specifically implemented as follows: The spherical coordinate system beam scanning space is projected onto the sinusoidal space to form an area, which is composed of the azimuth angle and elevation Determine that for each azimuth , the elevation angle has a range , the corresponding sinusoidal coordinates are ,according to , the beam width in sinusoidal space is the sine of the elevation normal beam width, and the elevation scanning range and the normal beam width are known, so the number of beams arranged in the elevation direction is calculated.

5. The distributed beam allocation method for low-orbit communication constellation according to claim 1, characterized in that: Step S3 is specifically implemented as follows: For the areas covered by low-orbit satellites, a coverage method combining wide beams and spot beams is adopted. The wide beam is used as a signaling beam, responsible for the transmission of ground service signaling messages within the satellite coverage area; the spot beam is a service beam, which is accessed in the form of beam hopping.

6. The distributed beam allocation method for low-orbit communication constellation according to claim 5, characterized in that: The time is divided into time slots based on the beam hopping method, and the utilization efficiency of limited resources is improved through the resource allocation algorithm.

7. The distributed beam allocation method for low-orbit communication constellation according to claim 6, characterized in that: The coverage area of ​​each satellite in the communication constellation is defined as a cell, where is the satellite number; each cell has elliptical wave positions, of which only There is a ground terminal inside each wave position, corresponding to the coverage position of the satellite spot beam; each spot beam coverage area is defined as a unit ; When the number of satellite beams is less than the number of units When Beam hopping is performed in each unit; in the satellite beam hopping working mode, the satellite's point beams reuse the same frequency band through time division.

8. The distributed beam allocation method for low-orbit communication constellation according to claim 7, characterized in that: The resource allocation algorithm is as follows: S3.1 counts the beam numbers of the ground terminals and the number of terminals in the coverage area of ​​the beam, and covers all the beam positions containing ground terminals in the form of beam hopping; S3.2 The spot beams are evenly divided in the wave positions with ground terminals. The length of time spent in a certain wave position is proportional to the number of terminals. S3.3 Assume that the satellite has spot beams, each beam can support There are ground terminals communicating. At a certain moment, the number of wave positions of ground terminals is , the total number of ground terminals is , The number of terminals in each of the wave positions is , ; The total communication time after deducting the consumption of beam hopping process is , then the residence time at each wave position is ; S3.4 Considering the same-frequency interference, ensure that the distance between two beams in the same frequency band reaches and above, among which is the beam radius; S3.5 optimizes the beam allocation result by considering the specified communication rate and communication capacity requirements of a single area; S3.6 performs beam resource allocation for each beam position, that is, calculates the two-dimensional matrix ,in ,correspond spot beams, ,correspond Wave position, Indicates the communication duration within, no. The spot beam is The dwell time at a wave position.

9. A distributed beam allocation system for low-orbit communication constellations, characterized in that: The system is used to implement the distributed beam allocation method for low-orbit communication constellation according to any one of claims 1 to 8, and the system comprises a satellite parameter configuration module, a beam allocation algorithm calculation module, and a beam allocation result display module; wherein: The satellite parameter configuration module is used to set the parameter configuration of the low-orbit communication constellation, including the number of constellation satellites, the current satellite number, the simulation initial time, the six elements of the orbit, the number of beams, the narrow beam width, and / or the maximum off-axis angle of the narrow beam; A ground scene configuration module, used to configure the configuration of ground terminal parameters, including the number of ground terminals, the longitude of the ground terminal, the latitude of the ground terminal, the height of the ground terminal, and / or the minimum elevation angle of the terminal; The beam allocation algorithm calculation module controls the calculation of the distributed beam allocation method of the low-orbit communication constellation by receiving the parameters of the satellite parameter setting module, calculates the position and speed of the satellite in the J2000 system using the six orbital numbers, and finally obtains the beam allocation matrix according to the beam allocation algorithm; The beam allocation result display module is used to display the beam allocation matrix received from the beam allocation algorithm calculation module, and finally visualize the beam coverage of different terminals on the interface.

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