A low earth orbit constellation multi-satellite multi-beam cooperative communication power frequency allocation method

Abstract

The application discloses a low-orbit constellation multi-satellite multi-beam cooperative communication power frequency allocation method, wherein a satellite collects downlink channel gain data in a scheduling period, and based on real-time channel conditions of a satellite terminal, iteration optimization is carried out between terminal access beams and beam transmitting power, frequency cooperation and energy cooperation among multi-satellite multi-beams are realized, and the satellite terminal can simultaneously access different satellite beams in different subbands, and the application can realize reasonable allocation of power resources and bandwidth resources of a satellite network and improve the capacity of the satellite network.

Description

Technical Field

[0001] This invention relates to a power and frequency allocation method for multi-satellite, multi-beam collaborative communication in low-Earth orbit constellations, belonging to the field of satellite communication technology. Background Technology

[0002] Satellites are indispensable nodes in 6G networks. In recent years, space-based information networks have developed rapidly, with satellite constellations becoming increasingly large and even gigantic, numbering in the tens of thousands. Orbital spacing is becoming increasingly congested, and multiple satellites sharing orbits has become the norm. Limited frequency and orbital resources are becoming increasingly strained, highlighting the scarcity of time, space, and frequency resources. The diverse nature, types, and demands of services, along with their severely uneven temporal and spatial distribution, mean that service needs vary across different beam coverage areas. This places high demands on the transmission capacity and efficient utilization of resources in satellite networks. However, in traditional multi-beam high-throughput satellite communication systems, the power and frequency resources allocated to each beam are fixed. This fixed payload design lacks sufficient flexibility to optimize satellite resource allocation, resulting in fragmented use of satellite resources and limiting satellite performance. More seriously, due to the diversity and differences in user service types, and the time-varying and spatially uneven distribution of services, this fragmented resource allocation leads to uneven resource utilization across beams, resulting in a huge waste of communication resources and making it difficult to achieve efficient transmission of diverse services and on-demand coverage of hotspot areas.

[0003] In practical systems, beam technologies can use partial or full frequency reuse. When using partial frequency reuse, the total satellite bandwidth is segmented, meaning each operational beam can only use a portion of the bandwidth. This approach effectively mitigates co-frequency interference at the expense of spectrum utilization efficiency. With full frequency reuse, each operational user beam can utilize the entire available bandwidth on the satellite, significantly improving bandwidth utilization efficiency.

[0004] How to effectively solve the spatiotemporal frequency interference of space systems and achieve compatible sharing of limited spatiotemporal frequency resources is an urgent problem to be solved in the full-frequency scheme to improve the capacity of satellite systems. Summary of the Invention

[0005] The technical problem solved by this invention is to address the shortcomings of existing technologies by proposing a power and frequency allocation method for multi-satellite multi-beam cooperative communication in low-Earth orbit constellations. With the goals of efficient utilization of frequency resources, saving satellite power consumption, and improving system capacity, this method proposes a power and frequency allocation method for multi-satellite multi-beam cooperative communication. Based on frequency and energy coordination among multiple beams, it achieves high-efficiency utilization of frequency and energy, thus solving the problem of optimized resource allocation in low-Earth orbit multi-beam satellite systems.

[0006] The technical solution of this invention is:

[0007] A power and frequency allocation method for multi-satellite, multi-beam cooperative communication in low-Earth orbit constellations includes the following steps:

[0008] 1) Divide the available downlink frequency band of the satellite network into N equal parts. s There are N sub-bands; the total number of communication satellites in the satellite network is N. c The total number of satellite terminals in the satellite network is N. u Each communication satellite includes N m One beam;

[0009] 2) Use This represents the transmit power allocated to the j-th beam of the i-th communication satellite in the n-th subband, based on the transmit power in the (z-1)-th solution period. For each sub-band, the access beam selection for the satellite terminal is performed to obtain the access beam selection result for each communication satellite.

[0010] 3) Based on the access beam selection results of each communication satellite obtained in step 2). Determine the optimal power allocation result;

[0011] 4) Based on the optimal power allocation result obtained in step 3), determine the data rate corresponding to the optimal power allocation result. The data rate This represents the data rate at which communication data is transmitted from the j-th beam to the k-th satellite terminal in the n-th subband of the i-th communication satellite; where i∈[1, N]. c ], j∈[1, N m ], n∈[1, N s ], k∈[1, N u ];

[0012] 5) Utilize the data rate determined in step 4). Determine the matching weight A for each satellite terminal in the current z-th solution cycle. z (k);

[0013] 6) Repeat steps 2) to 5) to obtain the matching weight A for each satellite terminal in each solution cycle. z (k), solve for the optimal power allocation result obtained in step 3) in the z-th solution cycle that maximizes |R(p(z))-R(p(z-1))| and |R(p(z))-R(p(z-1))|≤ε, and use it as the sub-band power allocation result to complete the allocation method;

[0014] Where ε is the convergence threshold, and R(p(z)) is equal to the matching weight A of all satellite terminals in the z-th solution cycle. zThe sum of (k); R(p(z-1)) equals the matching weight A corresponding to all satellite terminals in the (z-1)th solution cycle. z-1 The sum of (k).

[0015] Preferably, the access beam selection result in step 2) Indicates the first The communication channel for a satellite terminal to access the satellite network corresponds to the i-th communication satellite, the j-th beam, and the n-th subband.

[0016] Preferably, the access beam selection result in step 2) The following conditions must be met:

[0017] Access beam selection results Let the transmit power of the j-th beam of any i-th satellite in the satellite network be in the n-th subband. in, This represents the maximum transmit power constraint of the j-th beam of the i-th satellite in the n-th subband.

[0018] Preferably, the method for determining the optimal power allocation result in step 3) is as follows:

[0019] 31) Let any power allocation result be Each element represents the transmit power of the j-th beam of the i-th satellite in the corresponding n-th sub-band;

[0020] 32) Using a convex optimization method, based on all possible power allocation results and the access beam selection results... The power allocation result that maximizes g(p) - h(p) is taken as the optimal power allocation result;

[0021] Where g(p) represents the logarithmic weighted sum of the received power of the satellite terminal, and h(p) represents the logarithmic weighted sum of the received interference and noise power of the satellite terminal.

[0022] Preferably, the logarithmically weighted sum of the received power of the satellite terminal, g(p), is specifically:

[0023]

[0024] in, This represents the channel gain of the communication channel, corresponding to the signal transmitted from the i′-th communication satellite to the j′-th communication satellite in the n-th subband in a satellite network. A communication channel for transmitting data from a satellite terminal.

[0025] Preferably, the logarithmic weighted sum of the interference and noise power received by the satellite terminal, h(p), is specifically:

[0026]

[0027] in, Indicates and The corresponding transmission power, Indicates and The corresponding channel gain; It is the first The average rate from the time a satellite terminal accesses the communication channel to the present time, if the satellite terminal has never accessed the communication channel, then

[0028] Preferably, the data rate in step 4) The method for determining it is as follows:

[0029]

[0030] in, For signal-to-interference-plus-noise ratio.

[0031] Preferably, Specifically:

[0032]

[0033] Where N is the noise power.

[0034] Preferably, in step 5), the matching weight A z The method for determining (k) is as follows:

[0035]

[0036] ω(k)=1 / R k

[0037] in, R represents the data rate at which communication data is transmitted from the j-th beam of the i-th communication satellite to the k-th satellite terminal in the n-th subband; k ω(k) represents the average rate from the time the k-th satellite terminal accessed the communication channel until the current time; if the satellite terminal has not accessed the communication channel, then ω(k) = 1.

[0038] Preferably, in step 6), the convergence threshold ε is greater than 0 and not greater than 0.01.

[0039] The advantages of this invention compared to the prior art are:

[0040] (1) This invention breaks the traditional concept that a terminal can only access one beam. Through multi-beam collaboration, a satellite terminal can be served by multiple satellite beams in different sub-bands in each time slot, whereas traditionally, a satellite terminal can only access one beam in each time slot.

[0041] (2) This invention takes into account both satellite multi-beam power constraints and user real-time channel conditions, and performs differentiated allocation of beam bandwidth according to channel status. Compared with the hopping beam technique which is also limited by power, it can achieve user-level allocation and significantly improve system capacity.

[0042] (3) This invention breaks through the existing interference isolation method. All beams operate on all sub-bands and full frequency reuse is achieved. Compared with the existing satellite system's four-color or seven-color reuse, it improves the frequency efficiency of the satellite system. Attached Figure Description

[0043] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0044] A power and frequency allocation method for multi-satellite, multi-beam collaborative communication in a low-Earth orbit constellation is proposed. The satellite collects downlink channel gain data within a scheduling cycle. Based on the real-time channel conditions of the satellite terminal, iterative optimization is performed between the terminal access beam and the beam transmit power to achieve frequency and energy coordination among multiple satellites and multiple beams. The satellite terminal can simultaneously access different satellite beams in different subbands, enabling reasonable allocation of satellite network power and bandwidth resources and improving satellite network capacity.

[0045] like Figure 1 As shown, the present invention provides a power and frequency allocation method for multi-satellite multi-beam cooperative communication in a low-Earth orbit constellation, comprising the following steps:

[0046] 1) Divide the available downlink frequency band of the satellite network into N equal parts. s There are N sub-bands; the total number of communication satellites in the satellite network is N. c The total number of satellite terminals in the satellite network is N. u Each communication satellite includes N m One beam;

[0047] 2) Use This represents the transmit power allocated to the nth subband of the j-th beam of the i-th communication satellite, based on the transmit power in the (z-1)-th solution period. For each sub-band, the access beam selection for the satellite terminal is performed to obtain the access beam selection result for each communication satellite.

[0048] Access beam selection results Indicates the first Each satellite terminal accesses the satellite network through a communication channel corresponding to the i-th communication satellite, the j-th beam, and the n-th subband; where i ∈ [1, N]. c ], j∈[1, N m ], n∈[1, N s ].

[0049] The access beam selection result This enables the transmit power of the j-th beam of any i-th satellite in the n-th subband to be increased. Let represent the maximum transmit power constraint of the j-th beam of the i-th satellite in the n-th subband. Initially, let Get the corresponding

[0050] 3) Obtain the access beam selection results for each communication satellite based on step 2). Determine the optimal power allocation result to obtain the transmit power of the j-th beam of each satellite in the satellite network on the corresponding n-th subband in the current z-th solution cycle.

[0051] The method for determining the optimal power allocation result is as follows:

[0052] 31) Let any power allocation result be Each element represents the transmit power of the j-th beam of the i-th satellite in the corresponding n-th subband;

[0053] 32) Using a convex optimization method, based on all possible power allocation results and the access beam selection results... The optimal power allocation result is obtained by finding the power allocation result that maximizes g(p)-h(p); where g(p) represents the logarithmic weighted sum of the power received by the satellite terminal, and h(p) represents the logarithmic weighted sum of the power received by the satellite terminal from interference and noise.

[0054] The logarithmically weighted sum of the received power of the satellite terminal, g(p), is specifically:

[0055]

[0056] in, This represents the channel gain of the communication channel, corresponding to the j′ beam of the i′-th communication satellite in the satellite network using the nth subband to the j′-th beam. A communication channel for transmitting data from a satellite terminal.

[0057] The logarithmic weighted sum of the interference and noise power received by the satellite terminal, h(p), is specifically as follows:

[0058]

[0059] in, Indicates and The corresponding transmission power, Indicates and The corresponding channel gain; It is the first The average rate from the time a satellite terminal accesses the communication channel to the present time, if the satellite terminal has never accessed the communication channel (never been scheduled), then

[0060] 4) Based on the optimal power allocation result obtained in step 3), determine the data rate corresponding to the optimal power allocation result. Data rate This represents the data rate at which communication data is transmitted from the j-th beam to the k-th satellite terminal using the n-th subband in the i-th communication satellite.

[0061] Step 4) Determine the data rate The method is as follows:

[0062]

[0063] in, Signal-to-interference-plus-noise ratio (SINR);

[0064] The Specifically:

[0065]

[0066] Where N is the noise power.

[0067] 5) Utilize the data rate determined in step 4). Determine the matching weight A for each satellite terminal in the current z-th solution cycle. z (k);

[0068]

[0069] ω(k)=1 / R k

[0070] in, R represents the data rate at which communication data is transmitted from the j-th beam to the k-th satellite terminal using the n-th subband in the i-th communication satellite; k ω(k) represents the average rate from the time the k-th satellite terminal accessed the communication channel until the current time; if the satellite terminal has never accessed the communication channel (has never been scheduled), then ω(k) = 1.

[0071] 6) Repeat steps 2) through 5) to obtain the matching weight A corresponding to each solution cycle. z(k) is solved to maximize |R(p(z))-R(p(z-1))| and |R(p(z))-R(p(z-1))|≤ε. The optimal power allocation result corresponding to step 3) in the z-th solution cycle is used as the sub-band power allocation result to complete the allocation method.

[0072] Wherein, the convergence threshold ε is greater than 0 and not greater than 0.01; R(p(z)) is equal to the z-th solution cycle, and the matching weight A corresponding to each satellite terminal. z The sum of (k); R(p(z-1)) equals the (z-1)th solution cycle, and the matching weight A corresponding to each satellite terminal. z-1 The sum of (k).

[0073] Example

[0074] Satellite terminals include satellite handheld terminals, vehicles, aircraft, and ships. Nine communication satellites are centrally allocated power and frequency resources. These satellites are multi-beam satellites, covering different areas with multiple beams. Each satellite has 19 beams. Due to limitations in weight, size, and energy consumption, the transmission power is restricted, with a maximum power of 200W per beam. The antenna aperture is 1.2m, and the operating frequency band is 19.6GHz. The satellite orbital altitude is 1000km. The noise power spectral density is set to -174dBm / Hz. The total operating frequency band is 400MHz, divided into 20 sub-bands, each 20MHz. The convergence threshold ε = 0.0001.

[0075] The implementation process of this invention is as follows:

[0076] (1) In a satellite network system, communication satellites serve satellite terminals, which access a specific communication satellite through a subband. The available downlink frequency band of the satellite network, 400MHz, is divided into N equal parts. s = 20 sub-bands. The total number of satellites in this network is N. c =9. Each satellite includes N m =19 beams, N exists in the network u A satellite terminal. A resource-centralized allocation satellite is a satellite in a satellite network used to allocate satellite resources (power, frequency) among various communication satellites.

[0077] (2) The channel state information estimated by each satellite terminal is sent to the resource-centralized allocation satellite through the feedback channel of the satellite network; using This represents the channel gain of the communication channel, corresponding to the communication channel in the satellite network where the j-th beam of the i-th communication satellite transmits data to the k-th satellite terminal using the n-th subband.

[0078] (3) Use This represents the power allocated to the nth subband of the j-th beam of the i-th communication satellite, based on a given transmit power. For each sub-band, the access beam selection for the satellite terminal is performed to obtain the access beam selection result for each communication satellite.

[0079] Use binary variables This indicates the sub-band allocation result. This indicates that the nth subband of the jth beam in the i-th communication satellite is assigned to the k-th satellite terminal; otherwise... Where i∈[1, N] c ], j∈[1, N m ], n∈[1, N s ], k∈[1, N u ].

[0080] Obtain the access beam selection results for each communication satellite. The method is as follows:

[0081] 31) Calculate the data rate transmitted from the j-th beam to the k-th satellite terminal from the i-th communication satellite in the n-th subband. The method is as follows:

[0082]

[0083]

[0084] in, is the signal-to-interference-plus-noise ratio (SINR); N is the noise power.

[0085] Let the communication satellite beam set be {b} i,j} and satellite terminal set {u k Each terminal corresponds to a weight A. z (k), with Using weights, satellite beams and satellite terminals are matched to maximize the sum of the matched weights. The matching result is the satellite beam access selection result on subband n. Here, ω(k)∈(0,1] represents the priority of the k-th satellite terminal.

[0086] When selecting access in step (3):

[0087] A satellite terminal can simultaneously access different satellite beams on different subbands. Multiple beams accessing the same satellite terminal can belong to the same satellite or different satellites. A satellite terminal can access multiple beams of multiple satellites through different subbands. Within the same subband, it can only access one beam of the same satellite. One subband corresponds to only one beam of one satellite; it cannot be one-to-many. A terminal can use multiple subbands to transmit data.

[0088] (4) After selecting the access beam, under the constraints of satellite power and frequency, determine the transmit power of each satellite and each beam in each subband. The power allocation in step (4) is as follows:

[0089] The power allocation for each sub-band of each beam for each satellite is as follows:

[0090]

[0091] Find the power distribution p that maximizes g(p) - h(p).

[0092]

[0093]

[0094] in, This represents the beam access selection result obtained from step (3). It is the first The average rate from the time a satellite terminal accesses the communication channel to the present time, if the satellite terminal has never accessed the communication channel (never been scheduled), then

[0095] For satellite terminal index, indicating the first A satellite terminal accesses the nth subband of the jth beam in the i-th communication satellite.

[0096] At the initial moment, let Get the corresponding The maximum transmit power constraint of the j-th beam of the i-th satellite in the n-th subband is represented by the known input condition.

[0097] Specifically, the satellite power, frequency, and user rate requirements in step (4) are constrained as follows:

[0098] 41) On each subband, a satellite terminal can connect to at most one beam;

[0099] 42) On each sub-band, one beam can serve at most one satellite terminal;

[0100] 43) The transmit power of the j-th beam of the i-th satellite in the n-th subband is

[0101] in, This represents the transmit power of the j-th beam of the i-th satellite in the n-th subband.

[0102] (5) Based on the power allocation results in step (4), repeat steps (3) to (5) until the system weighted rate sum cannot gain an advantage. The system weighted rate sum is the basis for evaluating the quality of the system power frequency allocation results, and it is the weighted rate sum of each satellite terminal in the satellite network system. The specific calculation method is as follows:

[0103]

[0104] (6) Update user priority and allocate the remaining subband power according to steps (3) to (5).

[0105] The user priority update method in step (6) is as follows: for users who have not been scheduled, ω(k) = 1; for users who have been scheduled, ω(k) = 1 / R. k R k It is the average data rate from the time the k-th satellite terminal accessed the communication channel until the current time. The purpose of priority is to enable satellite terminals with low data rates due to insufficient resource allocation in the past to receive more resources in the next scheduling cycle by increasing their priority. Different satellite terminals (i.e., users) can have the same priority.

[0106] The specific steps for solving the power allocation p are as follows:

[0107] 61) Set z = 0,

[0108] 62) Solve The maximization problem, which is a convex optimization problem, can be solved using methods for convex optimization problems. This is well-known and will not be elaborated upon in this invention. The solution p is obtained. * ;

[0109] 63) Set z = z + 1, p(z) = p*, calculate R(p(z)), and repeat steps 3) to 4) until |R(p(z)) - R(p(z-1))| ≤ ε. Where R(p(z)) equals the matching weight A corresponding to each satellite terminal in the z-th solution cycle. z The sum of (k); R(p(z-1)) equals the (z-1)th solution cycle, and the matching weight A corresponding to each satellite terminal. z-1The summation of (k), where ε is the convergence threshold.

[0110] (7) After all sub-band power allocation is completed, resource scheduling is performed according to the resource allocation scheme;

[0111] (8) After one allocation cycle ends, the next allocation cycle begins.

[0112] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

[0113] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A power and frequency allocation method for multi-satellite, multi-beam cooperative communication in low-Earth orbit constellations, characterized in that, Includes the following steps: 1) Divide the available downlink frequency band of the satellite network into equal parts. Sub-band; the total number of communication satellites in the satellite network is The total number of satellite terminals in the satellite network is Each communication satellite includes One beam; 2) Use This represents the transmit power allocated to the j-th beam of the i-th communication satellite in the n-th subband, based on the transmit power in the (z-1)-th solution period. For each sub-band, the access beam selection for the satellite terminal is performed to obtain the access beam selection result for each communication satellite. ; 3) Based on the access beam selection results of each communication satellite obtained in step 2). Determine the optimal power allocation result; 4) Based on the optimal power allocation result obtained in step 3), determine the data rate corresponding to the optimal power allocation result. The data rate This represents the data rate at which communication data is transmitted from the j-th beam to the k-th satellite terminal in the n-th subband of the i-th communication satellite; where i ∈ [1, ..., ... ], j∈[1, ], n∈[1, ], k∈[1, ]; 5) Utilize the data rate determined in step 4). Determine the matching weights for each satellite terminal in the current z-th solution cycle. ; 6) Repeat steps 2) to 5) to obtain the matching weights for each satellite terminal in each solution cycle. Solving makes Maximum, and At that time, the optimal power allocation result obtained in step 3) in the z-th solution cycle is used as the sub-band power allocation result to complete the allocation method; in, For the convergence threshold, It equals the matching weight of all satellite terminals in the z-th solution cycle. The sum of all additions; It equals the matching weights corresponding to all satellite terminals in the (z-1)th solution cycle. The sum of .

2. The power and frequency allocation method for multi-satellite multi-beam cooperative communication in a low-Earth orbit constellation according to claim 1, characterized in that, Access beam selection results in step 2) The following conditions must be met: Access beam selection results Let the transmit power of the j-th beam of any i-th satellite in the satellite network be in the n-th subband. ;in, This represents the maximum transmit power constraint of the j-th beam of the i-th satellite in the n-th subband.

3. The power and frequency allocation method for multi-satellite multi-beam cooperative communication in a low-Earth orbit constellation according to claim 1, characterized in that, The method for determining the optimal power allocation result in step 3) is as follows: 31) Let any power allocation result be Each element represents the transmit power of the j-th beam of the i-th satellite in the corresponding n-th subband. 32) Using a convex optimization method, based on all possible power allocation results and the access beam selection results... Solve The maximum power allocation result is taken as the optimal power allocation result; in, This represents the logarithmic weighted sum of the received power of the satellite terminal. Logarithmically weighted sum of interference and noise power received by the satellite terminal.

4. The power and frequency allocation method for multi-satellite multi-beam cooperative communication in a low-Earth orbit constellation according to claim 3, characterized in that, The logarithmic weighted sum of the received power of the satellite terminal Specifically: in, This represents the channel gain of the communication channel, corresponding to the channel gain used in satellite networks. The first communication satellite The result of beam selection towards the access beam in the nth subband The corresponding communication channel for transmitting data to the satellite terminal; N It is noise power.

5. The power and frequency allocation method for multi-satellite multi-beam cooperative communication in a low-Earth orbit constellation according to claim 4, characterized in that, The logarithmic weighted sum of the interference and noise power received by the satellite terminal Specifically: in, Indicates and The corresponding transmission power, Indicates and The corresponding channel gain; ; This is the result of the access beam selection. The average data rate from the time the satellite terminal accessed the communication channel until the current time. If the satellite terminal has not accessed the communication channel, then... .

6. A power and frequency allocation method for low-Earth orbit constellation multi-satellite multi-beam cooperative communication according to any one of claims 4 or 5, characterized in that, Data rate in step 4) The method for determining it is as follows: in, For signal-to-interference-plus-noise ratio.

7. The power and frequency allocation method for multi-satellite multi-beam cooperative communication in a low-Earth orbit constellation according to claim 6, characterized in that, Specifically: 。 8. The power and frequency allocation method for multi-satellite multi-beam cooperative communication in a low-Earth orbit constellation according to claim 6, characterized in that, Matching weights in step 5) The method for determining it is as follows: in, This represents the data rate at which communication data is transmitted from the j-th beam of the i-th communication satellite to the k-th satellite terminal in the n-th subband. This represents the average data rate from the time the k-th satellite terminal accessed the communication channel until the current time; if the satellite terminal has never accessed the communication channel, then... .

9. A power and frequency allocation method for multi-satellite multi-beam cooperative communication in a low-Earth orbit constellation according to claim 6, characterized in that, Convergence threshold in step 6) Greater than 0 and not greater than 0.01.

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