A power distribution method and device for multi-beam satellite communication

Abstract

This invention discloses a power allocation method and apparatus for multi-beam satellite communication, relating to the field of satellite communication. The method includes: determining the gain between satellite beams; determining the useful power and interference power received by the ground unit based on the gain, where the useful power is the power of the satellite beam corresponding to the ground unit, and the interference power is the power of other satellite beams; determining the channel capacity allocated to the satellite beams based on the useful power and interference power; and using the difference between the channel capacity and the required capacity of the ground unit as an objective function, determining the transmit power allocated to the satellite beams when the objective function is minimized. Minimizing the difference between the channel capacity and the required capacity of the ground unit, i.e., meeting system requirements as the optimization objective, adjusts the transmit power of the satellite beams, thereby improving system resource utilization. Simultaneously, interference between satellite beams is considered when calculating the objective function, ensuring the communication quality for users.

Description

Technical Field

[0001] This invention relates to the field of satellite communications, and in particular to a power allocation method and apparatus for multi-beam satellite communications. Background Technology

[0002] In a multi-beam satellite communication system, the ground station is covered by multiple beams. When a user has a service request, the ground station sends a link request to the NCC (Network Control Center) via satellite. The NCC allocates resources appropriately based on the current system resource usage and then forwards the resource allocation result back to the ground station via satellite. The ground station then transmits the service data in the corresponding channel according to the resource allocation result. In practical multi-beam satellite communication systems, to expand communication capacity, co-frequency multiplexing technology is usually used, that is, different beams share the same frequency for communication. However, this approach also brings the problem of co-frequency interference between beams. Since the sidelobe gain of a multi-beam antenna is not zero, when different beams use the same frequency simultaneously, it will cause mutual interference between propagating signals, thus affecting the user's communication quality. Summary of the Invention

[0003] The purpose of this invention is to provide a power allocation method and apparatus for multi-beam satellite communication. By optimizing the system to meet system requirements, the transmission power of satellite beams is adjusted, thereby improving system resource utilization. Simultaneously, interference between satellite beams is considered when calculating the objective function, ensuring the quality of communication for users.

[0004] To address the aforementioned technical problems, this invention provides a power allocation method for multi-beam satellite communication, comprising:

[0005] Determine the gain between satellite beams;

[0006] The useful power and interference power received by the ground unit are determined based on the gain, wherein the useful power is the power of the satellite beam corresponding to the ground unit, and the interference power is the power of other satellite beams;

[0007] The channel capacity allocated to the satellite beam is determined based on the useful power and the interference power, and the channel capacity is positively correlated with the transmit power of the satellite beam.

[0008] The difference between the channel capacity and the required capacity of the ground unit is used as the objective function. When the objective function reaches its minimum value, the transmit power allocated to the satellite beam is determined.

[0009] On the other hand, determining the gain between satellite beams includes:

[0010] Determine the azimuth angle of the satellite antenna ;

[0011] Where θ is the directional angle of the satellite antenna, R is the distance from the Earth's center to the Earth's surface, and H is the distance from the satellite to the Earth's surface. The arc length between the satellite beam aiming line m and the ground element n;

[0012] The amplitude characteristic function corresponding to the gain between satellite beams is determined based on the included angle of the satellite antenna direction. ;

[0013] in, The angle between beam l and beam k is Gain at time, For maximum transmit antenna gain, This represents the gain of the inner sidelobe of the peak gain. Here, a represents the satellite beamwidth, and b represents the gain parameters. The angle at 0dB.

[0014] On the other hand, determining the useful power received by the ground unit based on the gain includes:

[0015] The expression for determining the useful power received by the ground unit based on the gain is as follows: ;

[0016] in, Let γ be the useful power received by ground cell k, and γ be the fading factor. The transmit power allocated to satellite beam k. For maximum transmit antenna gain, Let be the receiving antenna gain of ground element k, and d be the path distance from the satellite to the ground element. λ represents the free space path loss, and λ is the wavelength.

[0017] On the other hand, determining the interference power received by the ground unit based on the gain includes:

[0018] The expression for determining the interference power received by the ground unit based on the gain is as follows: ;

[0019] in, Let K be the interference power received by ground unit k, and K be the total number of satellite beams. The transmit power allocated to satellite beam l, The angle between beam l and beam k is Gain at time, for The result after normalization.

[0020] On the other hand, determining the channel capacity allocated to the satellite beam based on the useful power and the interference power includes:

[0021] The expression for determining the channel capacity allocated to the satellite beam based on the useful power and the interference power is as follows: ;

[0022] Among them, C k SINR is the channel capacity allocated to satellite beam k for the satellite. k Let be the signal-to-dryness ratio (SDR) of the point beam k, and α be the attenuation coefficient of the transmission channel. The expression for the SDR of the point beam k is: The expression for the attenuation coefficient of the transmission channel is as follows: N0 is the noise power spectral density, and B is the satellite beam bandwidth.

[0023] On the other hand, the difference between the channel capacity and the required capacity of the ground unit is used as the objective function, including:

[0024] The difference between the channel capacity and the required capacity of the ground unit is used as the objective function, and the expression of the objective function is as follows: ;

[0025] Where P is the objective function for the difference between the channel capacity and the required capacity of the ground unit, and C k D represents the channel capacity of the satellite beam. k K represents the required capacity of the ground unit, and K represents the total number of satellite beams.

[0026] On the other hand, when the objective function reaches its minimum value, determining the transmit power allocated to the satellite beam includes:

[0027] When the objective function reaches its minimum value and the constraints are satisfied, the transmit power allocated to the satellite beam is determined;

[0028] The constraints include , , and p k P is the transmit power of satellite beam k. T p is the total available power that the satellite can provide. m The maximum transmit power of a single satellite beam. This is the channel capacity threshold.

[0029] On the other hand, the difference between the channel capacity and the required capacity of the ground unit is used as the objective function. When the objective function reaches its minimum value, the transmit power allocated to the satellite beam is determined, including:

[0030] The position and velocity of each particle are initialized using the particle swarm optimization algorithm, and each particle represents the transmission power of the satellite beam.

[0031] Calculate the fitness function, which characterizes the value of the objective function;

[0032] Determine whether the fitness function satisfies the termination condition;

[0033] If the termination condition is not met, the values ​​of the fitness function are sorted in descending order, and the latter half is deleted.

[0034] The remaining fitness function values ​​are then sorted in descending order, with the larger half designated as the first class and the smaller half as the second class.

[0035] Arbitrarily select two fitness functions from the first class, and use a genetic algorithm to perform crossover and mutation calculations;

[0036] The fitness function in the second category is mutated using a genetic algorithm.

[0037] The first and second fitness functions obtained from the genetic algorithm are merged into a new population, and the steps for calculating the fitness function are returned.

[0038] If the termination condition is met, the optimal particle will be output, whereby the optimal particle represents the satellite beam transmission power when the objective function is minimized.

[0039] On the other hand, two fitness functions are arbitrarily selected from the first class, and crossover and mutation calculations are performed using a genetic algorithm, including:

[0040] Determine the maximum and average values ​​in the fitness function;

[0041] Arbitrarily select two fitness functions from the first class, and use a genetic algorithm to perform crossover and mutation calculations based on crossover and mutation probabilities;

[0042] The expression for the crossover probability is: The expression for the mutation probability is: ;

[0043] in, The maximum value in the fitness function. The average value of the fitness function is... The value of the larger of the two fitness functions. The values ​​of the fitness function for mutation are k1, k2, k3, and k4, which are all adjustment parameters.

[0044] To address the aforementioned technical problems, the present invention also provides a power distribution device for satellite communication, comprising:

[0045] Memory, used to store computer programs;

[0046] A processor is used to implement the power allocation method for satellite communication described above when executing the computer program.

[0047] This invention discloses a power allocation method and apparatus for multi-beam satellite communication, relating to the field of satellite communication. The method includes: determining the gain between satellite beams; determining the useful power and interference power received by the ground unit based on the gain, where the useful power is the power of the satellite beam corresponding to the ground unit, and the interference power is the power of other satellite beams; determining the channel capacity allocated to the satellite beams based on the useful power and interference power; and using the difference between the channel capacity and the required capacity of the ground unit as an objective function, determining the transmit power allocated to the satellite beams when the objective function is minimized. Minimizing the difference between the channel capacity and the required capacity of the ground unit, i.e., meeting system requirements as the optimization objective, adjusts the transmit power of the satellite beams, thereby improving system resource utilization. Simultaneously, interference between satellite beams is considered when calculating the objective function, ensuring the communication quality for users. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the prior art and embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 A flowchart illustrating a power allocation method for multi-beam satellite communication provided by the present invention;

[0050] Figure 2 This is a schematic diagram of the structure of a multi-beam satellite communication system provided by the present invention;

[0051] Figure 3 A schematic diagram of a ground unit and a satellite beam provided by the present invention;

[0052] Figure 4 A schematic diagram of the azimuth angle of a satellite antenna provided by the present invention;

[0053] Figure 5 A radiation direction relationship diagram provided by the present invention;

[0054] Figure 6 A flowchart for solving the objective function of particle swarm optimization is provided by the present invention;

[0055] Figure 7A schematic diagram of a crossover algorithm provided by the present invention;

[0056] Figure 8 A schematic diagram of a mutation algorithm provided by the present invention;

[0057] Figure 9 This is a schematic diagram of the structure of a power distribution device for multi-beam satellite communication provided by the present invention. Detailed Implementation

[0058] The core of this invention is to provide a power allocation method and apparatus for multi-beam satellite communication. By adjusting the transmission power of satellite beams to meet system requirements as the optimization objective, the system resource utilization rate is improved. Simultaneously, interference between satellite beams is considered when calculating the objective function, ensuring the communication quality for users.

[0059] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0060] Figure 2 This is a schematic diagram of the structure of a multi-beam satellite communication system provided by the present invention;

[0061] A complete multi-beam satellite communication system consists of, for example: Figure 2 As shown, the entire system can be divided into user segment, ground segment, and space segment.

[0062] User segment: Provides related business services to users, mainly including VSAT (Very Small Aperture Terminal), handheld terminals, mobile terminals, ships, aircraft or other various types of communication equipment.

[0063] Ground segment: The bridge between the user segment and the space segment, responsible for managing the satellite network and user services. It mainly consists of NCC (Network Control Center), GW (Gateway), Internet, PSTN (Public Switched Telephone Network), and PLMN (Public Land Mobile Network).

[0064] Space segment: Communication satellites serve as the core, processing signals received from the uplink and forwarding them to the downlink.

[0065] Based on their signal processing methods, relay satellites can be categorized into transparent relay satellites and processing relay satellites. Processing relay satellites receive signals from ground users, perform data processing (such as decoding, compression, and routing), and then forward the processed data to ground units. Processing relay satellites have their own data processing and routing capabilities, enabling signal processing, management, and optimization. Unlike processing relay satellites, transparent relay satellites do not possess data processing capabilities; they only receive signals from ground users, perform frequency conversion, amplification, and relay, but do not process or decode the signals.

[0066] The system composition of a single-beam satellite communication system is basically the same as that of a multi-beam satellite communication system. The difference lies in that in a single-beam satellite communication system, all ground stations are covered by the same beam, while in a multi-beam satellite communication system, ground stations are covered by multiple beams. When a user has a service request, the ground station sends a link request to the NCC via satellite. The NCC allocates resources appropriately for the link request based on the current system resource usage, and then forwards the resource allocation result to the ground station via satellite. The ground station then transmits service data in the corresponding channel according to the resource allocation result.

[0067] In practical multi-beam satellite communication systems, co-frequency reuse is commonly used to expand communication capacity, meaning different beams share the same frequency for communication. However, this approach also introduces the problem of co-frequency interference between beams. Because the sidelobe gain of a multi-beam antenna is not zero, when different beams use the same frequency simultaneously, mutual interference between propagating signals occurs, affecting the user's communication quality. Research has found that when inter-beam interference exists, the communication capacity allocated to each beam depends not only on the power allocated to that beam but also on the power distribution to other beams.

[0068] Figure 1 The flowchart illustrates a power allocation method for multi-beam satellite communication provided by the present invention. This power allocation method for multi-beam satellite communication includes:

[0069] S11: Determine the gain between satellite beams;

[0070] In multi-beam satellite communication, if different beams communicate on the same frequency, their signals will interfere with each other, degrading communication quality. This interference mainly comes from beam sidelobe radiation and cross-mode interference effects. When sidelobes overlap, cross-interference occurs; due to cross-mode characteristics between antenna beams, one beam's signal can interfere with other beams. The distribution of co-channel interference varies depending on the distance between beams, with closer beams exhibiting more significant interference. Unlike beam hopping technology, co-channel interference in multi-beam satellites cannot be eliminated through spatial isolation. Therefore, it is necessary to first determine the interference between satellite beams, i.e., the gain.

[0071] S12: Determine the useful power and interference power received by the ground unit based on the gain. The useful power is the power of the satellite beam corresponding to the ground unit, and the interference power is the power of other satellite beams.

[0072] Figure 3 A schematic diagram of a ground unit and a satellite beam provided by the present invention;

[0073] The correspondence between ground units and beams is as follows: Figure 3 As shown.

[0074] When satellite beam 11 transmits information to the corresponding ground unit, it will be interfered with by other beams. Among them, satellite beams 8, 9, and 12 interfere with beam 11 the most because they are adjacent and the location is closest. Similarly, satellite beams 4, 5, 6, and 10 will also interfere with satellite beam 11, but the interference is relatively reduced due to the greater distance, but it still exists.

[0075] However, only satellite beam 11 is useful to the ground unit; the other satellite beams are interference. Therefore, the ground unit uses satellite beam 11 as the received useful power and all the remaining satellite beams as interference power.

[0076] S13: Determine the channel capacity allocated to the satellite beam based on the useful power and interference power. The channel capacity is positively correlated with the transmit power of the satellite beam.

[0077] S14: Use the difference between the channel capacity and the required capacity of the ground unit as the objective function, and determine the transmit power allocated to the satellite beam when the objective function reaches its minimum value.

[0078] In multi-beam mode, the main problems are the differentiation of ground unit services and changes in beam channel state. After comprehensive consideration, the ultimate optimization goal is to minimize the squared mean of service demand capacity and beam allocation capacity, i.e., the unmet system capacity. This aims to enable timely adjustments to power resource allocation when service demands or channel states change, thereby improving system resource utilization. The number of working beams in the downlink is K, equivalent to the number of ground units. Satellite resources are allocated according to service demand, aiming to allocate resources to each beam to meet beam demand capacity as much as possible while satisfying resource constraints.

[0079] This invention discloses a power allocation method for multi-beam satellite communication, relating to the field of satellite communication. The method includes: determining the gain between satellite beams; determining the useful power and interference power received by the ground unit based on the gain, where the useful power is the power of the satellite beam corresponding to the ground unit, and the interference power is the power of other satellite beams; determining the channel capacity allocated to the satellite beams based on the useful power and interference power; using the difference between the channel capacity and the required capacity of the ground unit as an objective function, and determining the transmit power allocated to the satellite beams when the objective function is minimized. Minimizing the difference between the channel capacity and the required capacity of the ground unit, i.e., meeting system requirements as the optimization objective, adjusts the transmit power of the satellite beams, thereby improving system resource utilization. Simultaneously, interference between satellite beams is considered when calculating the objective function, ensuring the communication quality for users.

[0080] Based on the above embodiments:

[0081] In some embodiments, determining the gain between satellite beams includes:

[0082] Determine the azimuth angle of the satellite antenna ;

[0083] Where θ is the directional angle of the satellite antenna, R is the distance from the Earth's center to the Earth's surface, and H is the distance from the satellite to the Earth's surface. The arc length between the satellite beam aiming line m and the ground element n;

[0084] The amplitude characteristic function corresponding to the gain between satellite beams is determined based on the included angle of the satellite antenna direction. ;

[0085] in, The angle between beam l and beam k is Gain at time, For maximum transmit antenna gain, This represents the gain of the inner sidelobe of the peak gain. Here, a represents the satellite beamwidth, and b represents the gain parameters. It is the off-axis angle. The angle at 0dB.

[0086] Figure 4 A schematic diagram of the azimuth angle of a satellite antenna provided by the present invention;

[0087] Since the satellite and ground unit exchange information via broadcast beams during the network access phase, and given that the satellite's and ground unit's position information, beam identification, etc., are known, and without considering oblique projection, the geocentric angle between the satellite beam aiming line m and the ground unit n (i.e., the center angle) can be calculated using the arc length calculation formula. Then, based on the calculated directional angle, the satellite's position, and the center information of the ground unit n, combined with the cosine theorem, the satellite antenna directional angle can be determined. That is, the off-axis angle.

[0088] After obtaining the azimuth angle of the satellite antenna, we can further analyze the inter-beam interference problem. Considering that antenna sidelobes are the main problem of inter-beam interference, for the sake of analysis, we assume that all point beams of the satellite use the same type of antenna. Due to the extension of the antenna sidelobes, the main lobe of the point beam overlaps with the sidelobes of other beams to a certain extent, resulting in inter-beam interference under the condition of full-frequency reuse.

[0089] In the amplitude characteristic function, a is typically set to 2.88 and b to 6.32. The value is -25dB. The satellite beamwidth is 3dB.

[0090] The specific radiation direction relationship diagram is as follows: Figure 5 As shown, Figure 5 A radiation direction relationship diagram is provided for this invention.

[0091] In some embodiments, determining the useful power received by the ground unit based on the gain includes:

[0092] The expression for determining the useful power received by the ground unit based on the gain is as follows: ;

[0093] in, P is the useful power received by ground cell k, γ is the fading factor, and P is the fading power. k The transmit power allocated to satellite beam k. For maximum transmit antenna gain, Let be the receiving antenna gain of ground element k, and d be the path distance from the satellite to the ground element. λ represents the free space path loss, and λ is the wavelength.

[0094] The useful power received by a ground unit is the power of the satellite beam corresponding to that ground unit. It can be understood that the number of ground units and the number of satellite beams are in one-to-one correspondence. Ground unit k corresponds to satellite beam k. Only the data received by the kth ground unit from satellite beam k is the useful data. At the same time, the received useful power needs to take into account the transmission power allocated by the satellite to satellite beam k, the transmission distance from the satellite to the ground unit, and the loss during the transmission process.

[0095] In some embodiments, determining the interference power received by the ground unit based on the gain includes:

[0096] The expression for determining the interference power received by the ground unit based on the gain is as follows: ;

[0097] in, Let K be the interference power received by ground unit k, and K be the total number of satellite beams. The transmit power allocated to satellite beam l, The angle between beam l and beam k is Gain at time, for The result after normalization.

[0098] The interference power received by the ground unit is the power of all satellite beams except the satellite beam corresponding to the ground unit. It can be understood that the number of ground units corresponds one-to-one with the number of satellite beams. Ground unit k corresponds to satellite beam k. Only the data received by the kth ground unit from satellite beam k is useful data. The remaining K-1 satellite beams are all interference. At the same time, the received interference power needs to take into account the transmission power allocated by the satellite to satellite beam l, the transmission distance from the satellite to the ground unit, and the loss during transmission.

[0099] In some embodiments, determining the channel capacity allocated to a satellite beam based on useful power and interference power includes:

[0100] The expression for determining the channel capacity allocated to a satellite beam based on useful power and interference power is as follows: ;

[0101] Among them, C k SINR is the channel capacity allocated to satellite beam k for the satellite. k Let be the signal-to-dryness ratio (SDR) of a point beam k, and α be the attenuation coefficient of the transmission channel. The expression for the SDR of a point beam k is: The expression for the attenuation coefficient of the transmission channel is: N0 is the noise power spectral density, and B is the satellite beam bandwidth.

[0102] α represents the attenuation coefficient of the transmission channel, which is affected by antenna gain, free space loss, rain attenuation, etc. Channel capacity is determined according to Shannon's formula.

[0103] In some embodiments, the difference between channel capacity and the required capacity of ground units is used as the objective function, including:

[0104] The difference between the channel capacity and the required capacity of the ground unit is taken as the objective function, and the expression of the objective function is: ;

[0105] Where P is the objective function for the difference between channel capacity and the required capacity of ground units, and C k D represents the channel capacity of the satellite beam. k K represents the required capacity of the ground unit, and K represents the total number of satellite beams.

[0106] In multi-beam configurations, the differentiation of ground unit services and changes in beam channel states are the main challenges. Taking all factors into consideration, minimizing the squared mean of service demand capacity and beam allocation capacity (i.e., unmet system capacity) is the ultimate optimization objective. This aims to enable timely adjustments to power resource allocation when service demands or channel states change, thereby improving system resource utilization. Assume that the downlink under study has K operating beams, covering K ground units with no overlapping coverage areas. Satellite resources are allocated based on service demand, aiming to allocate resources to each beam to meet beam demand capacity as much as possible while satisfying resource constraints.

[0107] In some embodiments, determining the transmit power allocated to the satellite beam when the objective function is minimized includes:

[0108] When the objective function is minimized and the constraints are satisfied, determine the transmit power allocated to the satellite beam;

[0109] Among them, the constraints include , , and , The transmit power of satellite beam k, The total available power that the satellite can provide. The maximum transmit power of a single satellite beam. This is the channel capacity threshold.

[0110] The first constraint states that the total power of all beams cannot exceed the available power that the satellite can provide; the second constraint states that the capacity allocated to each beam is not greater than the amount of service requests, so as to achieve effective utilization of resources; the third constraint limits the maximum transmit power of a single beam; and the fourth constraint states that resource allocation must meet the user's quality of service requirements, ensuring that the beam's throughput is greater than the throughput threshold and meets the minimum service requirements.

[0111] Figure 6 A flowchart for solving the objective function of particle swarm optimization is provided by the present invention;

[0112] In some embodiments, the difference between the channel capacity and the required capacity of the ground unit is used as the objective function. When the objective function is minimized, the transmit power allocated to the satellite beam is determined, including:

[0113] The position and velocity of each particle are initialized using the particle swarm optimization algorithm, and each particle represents the transmit power of the satellite beam.

[0114] Calculate the fitness function, which represents the value of the objective function;

[0115] Determine whether the fitness function satisfies the termination condition;

[0116] If the termination condition is not met, sort the fitness function values ​​in descending order and delete the latter half.

[0117] The remaining fitness function values ​​are then sorted in descending order, with the larger half designated as the first class and the smaller half as the second class.

[0118] Arbitrarily select two fitness functions from the first class, and use a genetic algorithm to perform crossover and mutation calculations;

[0119] The fitness function in the second category is mutated using a genetic algorithm.

[0120] The first and second fitness functions obtained from the genetic algorithm are merged into a new population, and the steps for calculating the fitness function are returned.

[0121] If the termination condition is met, the optimal particle will be output. The optimal particle represents the satellite beam transmission power when the objective function is minimized.

[0122] The basic idea of ​​particle swarm optimization (PSO) based on genetic algorithm is to first initialize the position and velocity of each particle using PSO, and then use crossover and mutation of genetic algorithm to update the particle population, so as to avoid the PSO getting stuck in local optima and guide the particles to search for global optimization again.

[0123] Figure 7 A schematic diagram of a crossover algorithm provided by the present invention;

[0124] This paper introduces the chromosome crossover operation from genetic algorithms into particle swarm optimization (PSO). A subset of high-performing particles are selected as the evaluation criteria for the objective function. These particles are then crossbred with particles in the hybridization pool to generate offspring particles that replace the original particles, maintaining a constant total number of particles in the hybridization pool. Furthermore, information sharing between the original and offspring particles accelerates the algorithm's convergence speed. It is worth noting that the chromosome crossover probability is manually set according to specific requirements.

[0125] Figure 8A schematic diagram of a mutation algorithm provided by the present invention;

[0126] The mutation operation in genetic algorithms helps increase the diversity of the algorithm, thereby preventing particle swarm optimization from getting trapped in local optima. Specifically, mutation introduces new individuals and solutions by randomly changing certain characteristics or properties of particles, including their position, velocity, or other attributes. This introduces a degree of randomness and exploration into the solution space, allowing for a broader exploration of the search space. This helps to escape local optima and promotes the algorithm's search towards the global optimum.

[0127] In some embodiments, two fitness functions from the first class are arbitrarily selected, and a genetic algorithm is used to perform crossover and mutation calculations, including:

[0128] Determine the maximum and average values ​​in the fitness function;

[0129] Arbitrarily select two fitness functions from the first class, and use a genetic algorithm to perform crossover and mutation calculations based on crossover and mutation probabilities;

[0130] The expression for the crossover probability is: The expression for the mutation probability is: ;

[0131] in, The maximum value in the fitness function. The average value of the fitness function. The value of the larger of the two fitness functions. The values ​​of the fitness function for mutation are k1, k2, k3, and k4, which are all adjustment parameters.

[0132] Step 1: Population Initialization. Initialize the particle swarm parameters such as velocity and position using a random function.

[0133] Step 2: Fitness Calculation. Using the power optimization objective proposed in this paper as the fitness function, the fitness values ​​of all particles are calculated, and the fitness function values ​​are compared to determine the optimal fitness value for each individual particle and the optimal fitness value globally.

[0134] Step 3: Particle Swarm Parameter Improvement. To enhance the search capability of the genetic-particle swarm optimization algorithm, improved inertia weights and learning factors are introduced into the algorithm to improve its performance.

[0135] Step 4: Crossover and Mutation. The current population is updated by introducing crossover and mutation operations from the genetic algorithm, enhancing the global search capability and the algorithm's convergence ability. This paper employs a single-point crossover operator, randomly selecting a crossover position from paired chromosomes, replacing information, and generating and updating the population. To avoid inappropriate values ​​for crossover and mutation probabilities leading to search difficulties, adaptive crossover and mutation probabilities are introduced.

[0136] Step 5: Merge. Merge population A and population B, which have undergone crossover and mutation operations respectively, to generate a new complete population with the same number of individuals as the initial population size from the particle swarm optimization algorithm.

[0137] Step 6: Calculate the individual fitness and social fitness values ​​of the new population, compare them with the historical fitness values, and determine whether the maximum number of iterations has been reached. Once the maximum number of iterations has been reached, output the optimal result.

[0138] Figure 9 This is a schematic diagram of a power distribution device for multi-beam satellite communication provided by the present invention. The power distribution device for multi-beam satellite communication includes:

[0139] Memory 91 is used to store computer programs;

[0140] The processor 92 is used to implement the steps of the power allocation method for satellite communication described above when executing a computer program.

[0141] The description of the satellite communication power distribution device provided in this application is given in the above embodiments and will not be repeated here.

[0142] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0143] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0144] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A power allocation method for multi-beam satellite communication, characterized in that, include: Determine the gain between satellite beams; The useful power and interference power received by the ground unit are determined based on the gain, wherein the useful power is the power of the satellite beam corresponding to the ground unit, and the interference power is the power of other satellite beams besides the corresponding satellite beam. The channel capacity allocated to the satellite beam is determined based on the useful power and the interference power, and the channel capacity is positively correlated with the transmit power of the satellite beam. The difference between the channel capacity and the required capacity of the ground unit is used as the objective function. When the objective function reaches its minimum value, the transmit power allocated to the satellite beam is determined. Using the difference between the channel capacity and the required capacity of the ground unit as the objective function, the transmit power allocated to the satellite beam is determined when the objective function reaches its minimum value, including: The position and velocity of each particle are initialized using the particle swarm optimization algorithm, and each particle represents the transmit power of the satellite beam. Calculate the fitness function, which characterizes the value of the objective function; Determine whether the fitness function satisfies the termination condition; If the termination condition is not met, the values ​​of the fitness function are sorted in descending order, and the latter half is deleted. The remaining fitness function values ​​are then sorted in descending order, with the larger half designated as the first class and the smaller half as the second class. Arbitrarily select two fitness functions from the first class, and use a genetic algorithm to perform crossover and mutation calculations; The fitness function in the second category is mutated using a genetic algorithm. The first and second fitness functions obtained from the genetic algorithm are merged into a new population, and the steps for calculating the fitness function are returned. If the termination condition is met, the optimal particle will be output, whereby the optimal particle represents the satellite beam transmission power when the objective function is minimized.

2. The power allocation method for multi-beam satellite communication as described in claim 1, characterized in that, Determining the gain between satellite beams includes: Determine the azimuth angle of the satellite antenna ; Where θ is the directional angle of the satellite antenna, R is the distance from the Earth's center to the Earth's surface, and H is the distance from the satellite to the Earth's surface. The arc length between the satellite beam aiming line m and the ground element n; The amplitude characteristic function corresponding to the gain between satellite beams is determined based on the included angle of the satellite antenna direction. ; Among them, G l,k (θ) represents the gain when the angle between beam l and beam k is θ. m For maximum transmit antenna gain, L s θ represents the gain of the inner sidelobe of the peak gain. b θ is the satellite beamwidth, a and b are gain parameters, and θ1 is the angle at 0dB.

3. The power allocation method for multi-beam satellite communication as described in claim 1, characterized in that, Determining the useful power received by the ground unit based on the gain includes: The expression for determining the useful power received by the ground unit based on the gain is as follows: ; in, P is the useful power received by ground cell k, γ is the fading factor, and P is the fading power. k G is the transmit power allocated to satellite beam k. m For maximum transmit antenna gain, G r Let be the receiving antenna gain of ground element k, and d be the path distance from the satellite to the ground element. λ represents the free space path loss, and λ is the wavelength.

4. The power allocation method for multi-beam satellite communication as described in claim 3, characterized in that, Determining the interference power received by the ground unit based on the gain includes: The expression for determining the interference power received by the ground unit based on the gain is as follows: ; in, P represents the interference power received by ground unit k, where K is the total number of satellite beams. l For the transmit power allocated to satellite beam l, G l,k (θ) represents the gain when the angle between beam l and beam k is θ. l,k For G l,k The result after normalization.

5. The power allocation method for multi-beam satellite communication as described in claim 4, characterized in that, Determining the channel capacity allocated to the satellite beam based on the useful power and the interference power includes: The expression for determining the channel capacity allocated to the satellite beam based on the useful power and the interference power is as follows: ; Among them, C k SINR is the channel capacity allocated to satellite beam k for the satellite. k Let be the signal-to-interference-plus-noise ratio (SIR) of the spot beam k, and α be the attenuation coefficient of the transmission channel. The expression for the SIR of the spot beam k is: The expression for the attenuation coefficient of the transmission channel is as follows: N0 is the noise power spectral density, and B is the satellite beam bandwidth.

6. The power allocation method for multi-beam satellite communication as described in claim 1, characterized in that, The difference between the channel capacity and the required capacity of the ground unit is used as the objective function, including: The difference between the channel capacity and the required capacity of the ground unit is used as the objective function, and the expression of the objective function is as follows: ; Where P is the objective function for the difference between the channel capacity and the required capacity of the ground unit, and C k D represents the channel capacity of the satellite beam. k K represents the required capacity of the ground unit, and K represents the total number of satellite beams.

7. The power allocation method for multi-beam satellite communication as described in claim 6, characterized in that, When the objective function reaches its minimum value, the transmit power allocated to the satellite beam is determined, including: When the objective function reaches its minimum value and the constraints are satisfied, the transmit power allocated to the satellite beam is determined; The constraints include , , and p k P is the transmit power of satellite beam k. T p is the total available power that the satellite can provide. m The maximum transmit power of a single satellite beam. This is the channel capacity threshold.

8. The power allocation method for multi-beam satellite communication as described in claim 1, characterized in that, Arbitrarily select two fitness functions from the first class, and use a genetic algorithm to perform crossover and mutation calculations, including: Determine the maximum and average values ​​in the fitness function; Arbitrarily select two fitness functions from the first class, and use a genetic algorithm to perform crossover and mutation calculations based on crossover and mutation probabilities; The expression for the crossover probability is: The expression for the mutation probability is: ; in, The maximum value in the fitness function. Let f be the average of the fitness functions, and let f be the value of the larger of the two fitness functions. The values ​​of the fitness function for mutation are k1, k2, k3, and k4, which are all adjustment parameters.

9. A power distribution device for multi-beam satellite communication, characterized in that, include: Memory, used to store computer programs; A processor, configured to implement the power allocation method for multi-beam satellite communication as described in any one of claims 1 to 8 when executing the computer program.

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