CN112910537B - A kind of method and device for determining adaptive coding modulation mode of satellite communication - Google Patents

Abstract

The present application discloses a method and device for determining an adaptive coding modulation mode for satellite communication. The method includes: calculating a coverage area of a satellite according to preset satellite ground parameter information; Rain attenuation estimation method, communication frequency and electromagnetic wave technology are used to calculate the estimated value of rain attenuation in the coverage area, wherein the preset time availability includes sunny days and rainy days; under the preset time availability, according to the rain Calculate the signal-to-noise ratio SNR of the terminal corresponding to each location point in the coverage area, and calculate the SNR distribution probability in the coverage area; according to the SNR distribution The probability determines the satellite communication adaptive coding and modulation mode from a plurality of preset adaptive coding and modulation modes. The present application solves the technical problem of low spectral efficiency in the prior art.

Description

A kind of method and device for determining adaptive coding modulation mode of satellite communication

technical field

The present application relates to the technical field of satellite communications, and in particular, to a method and apparatus for determining an adaptive coding and modulation mode for satellite communications.

Background technique

In recent years, with the increasing demand for bandwidth and information rate of satellite communication, the frequency band used for data transmission is developing from Ku and Ka to higher. Since electromagnetic waves in higher frequency bands such as Ka are easily affected by the environment, such as rain, especially in harsh environments such as heavy rain or torrential rain, the attenuation of electromagnetic waves is very large, which seriously affects the quality of satellite communications. In order to ensure the quality of satellite communication, strategies against rain fading need to be considered in the satellite communication system.

At present, the commonly used and effective anti-rain fading method mainly adopts the Adaptive Coding Modulation (ACM) technology, in which the ACM technology can dynamically adjust the coding rate of each data frame according to the actual channel measurement of each received data frame. The modulation mode generally improves the channel utilization rate compared to the fixed rate system, thereby maximizing the utilization rate of spectrum resources. However, in the related protocols of the ACM technology, there are at least dozens of candidate coding and modulation schemes. Considering the problems of implementation complexity and frequent switching, the above-mentioned candidate coding and modulation schemes need to be screened. The existing strategy for screening coding and modulation methods is to perform preliminary screening according to the monotonically increasing relationship between the signal-to-noise ratio (SIGNAL NOISE RATIO, SNR) threshold and spectral efficiency of candidate coding and modulation methods, and then select the lowest-order and highest-order modulation and coding methods (Modulation and Within the scope of Coding Scheme, MCS), the principle of equal interval increment of SNR is adopted to dynamically determine the coding and modulation mode of each data frame.

Although, the MCS determined by the principle of increasing SNR at equal intervals can effectively reduce the switching times of transmission modes, and minimize the complexity of system implementation at the expense of lower average spectral efficiency. However, in a satellite communication system, the actual received SNR in the coverage area does not obey a uniform distribution. Therefore, the average spectral efficiency cannot be maximized by using the principle of increasing SNR at equal intervals, resulting in low spectral efficiency.

SUMMARY OF THE INVENTION

The technical problem solved by the present application is: aiming at the problem of low spectral efficiency in the prior art, a method and device for determining an adaptive coding and modulation mode for satellite communication are provided. In the solution provided by the example, the satellite coverage area is calculated first, and then the estimated value of rain attenuation under the preset time availability is calculated, that is, the estimated value of rain attenuation under sunny or rainy days is calculated, and then the estimated value of rain attenuation under sunny or rainy days is calculated. The attenuation estimation value calculates the SNR distribution probability in the coverage area, weights the spectral efficiencies of multiple preset adaptive coding and modulation methods according to the SNR distribution probability in the coverage area, and determines the auto with the highest spectral efficiency according to the principle of maximizing spectral efficiency. Adapt to the code modulation method. The problem that the average spectral efficiency cannot be maximized due to the principle of increasing SNR at equal intervals is avoided, thereby improving the spectral efficiency.

In a first aspect, an embodiment of the present application provides a method for determining an adaptive coding and modulation mode for satellite communication, the method comprising:

Calculate the coverage area of the satellite according to preset satellite ground parameter information, wherein the satellite ground parameter information includes satellite orbit height, earth radius, and latitude and longitude information of any position on the earth;

Under the preset time availability, calculate the estimated value of rain attenuation in the coverage area according to the preset rain attenuation estimation method, communication frequency and electromagnetic wave technology, wherein the preset time availability includes sunny days and rainy days;

Under the preset time availability, the satellite-ground link is calculated according to the estimated rain attenuation value and the preset communication information to obtain the terminal receiving signal-to-noise ratio SNR corresponding to each location point in the coverage area, and statistics SNR distribution probability within the coverage area;

According to the SNR distribution probability, an adaptive coding and modulation scheme for satellite communication is determined from a plurality of preset adaptive coding and modulation schemes.

Optionally, calculate the coverage area of the satellite according to the preset satellite parameter information, including:

The threshold value of the pointing angle of the satellite antenna is obtained by calculating according to the satellite orbit height, the earth radius and the preset belief angle threshold;

According to the satellite orbit height and the latitude and longitude information, the first antenna pointing angle set of all the position points on the earth is obtained through traversal calculation;

According to the threshold value, a second antenna pointing angle set smaller than the threshold value is selected from the first antenna pointing angle set, and it is determined that the position point corresponding to each antenna pointing angle in the second antenna pointing angle set is at The area where the earth is located, and the area is used as the coverage area.

Optionally, count the SNR distribution probability in the coverage area, including:

Determine the SNR corresponding to each position in sunny and rainy days respectively, and determine the SNR interval range corresponding to each position according to the corresponding SNR in sunny and rainy days;

The SNR distribution probability in the coverage area is obtained by performing statistics on each SNR value in the SNR interval range.

Optionally, the satellite communication adaptive coding and modulation mode is determined from a plurality of preset adaptive coding and modulation modes according to the SNR distribution probability, including:

Determine the spectral efficiency based on probability weighting corresponding to each of the preset adaptive coding and modulation modes according to the SNR distribution probability;

According to the spectral efficiency and preset constraints As the satellite communication adaptive coding modulation method.

Optionally, the preset constraints are expressed by the following formula:

Constraint C1:

Constraint C2:

Among them, the constraints C1 and C2 are respectively the minimum MCS interval and the maximum MCS interval constraint; 1≤i≤N.

Optionally, calculating the signal-to-noise ratio SNR corresponding to each location point in the coverage area according to the estimated rain attenuation value and preset communication information, including:

Calculate the signal-to-noise ratio SNR corresponding to each location point in the coverage area by the following formula:

Among them, EIRP is the effective isotropic radiation power emitted by the satellite; λ is the wavelength of the electromagnetic wave emitted by the satellite; d is the communication distance; B is the bandwidth of the satellite communication system; L _r is the receiving feed loss in the satellite communication system; L _other is the satellite communication system Other losses in ; G/T represents the terminal performance index; k=1.38×10 ^-23 is the Boltzmann constant.

In a second aspect, an embodiment of the present application provides a device for determining an adaptive coding and modulation mode for satellite communication, the device comprising:

The first calculation unit is used to calculate the coverage area of the satellite according to preset satellite parameter information, wherein the satellite parameter information includes satellite orbit height, earth radius and longitude and latitude information of any position point on the earth;

The second calculation unit is configured to calculate the estimated value of rain attenuation in the coverage area according to the preset rain attenuation estimation method, communication frequency and electromagnetic wave technology under the preset time availability, wherein the preset time Availability includes sunny and rainy days;

A statistical unit, configured to calculate the satellite-ground link according to the estimated rain attenuation value and the preset communication information under the preset time availability to obtain the terminal receiving signal-to-noise ratio corresponding to each location point in the coverage area SNR, and count the SNR distribution probability in the coverage area;

A determining unit, configured to determine a satellite communication adaptive coding and modulation mode from a plurality of preset adaptive coding and modulation modes according to the SNR distribution probability.

Optionally, the first computing unit is specifically used for:

The threshold value of the pointing angle of the satellite antenna is obtained by calculating according to the satellite orbit height, the earth radius and the preset belief angle threshold;

According to the satellite orbit height and the latitude and longitude information, the first antenna pointing angle set of all the position points on the earth is obtained through traversal calculation;

According to the threshold value, a second antenna pointing angle set smaller than the threshold value is selected from the first antenna pointing angle set, and it is determined that the position point corresponding to each antenna pointing angle in the second antenna pointing angle set is at The area where the earth is located, and the area is used as the coverage area.

Optionally, the statistical unit is specifically used for:

Determine the SNR corresponding to each position in sunny and rainy days respectively, and determine the SNR interval range corresponding to each position according to the corresponding SNR in sunny and rainy days;

The SNR distribution probability in the coverage area is obtained by performing statistics on each SNR value in the SNR interval range.

Optionally, the determining unit is specifically used for:

Determine the spectral efficiency corresponding to each of the preset adaptive coding and modulation modes according to the SNR distribution probability;

According to the spectral efficiency and preset constraints As the satellite communication adaptive coding modulation method.

Optionally, the preset constraints are expressed by the following formula:

Constraint C1:

Constraint C2:

Among them, the constraints C1 and C2 are respectively the minimum MCS interval and the maximum MCS interval constraint; 1≤i≤N.

Optionally, calculating the signal-to-noise ratio SNR corresponding to each location point in the coverage area according to the estimated rain attenuation value and preset communication information, including:

Calculate the signal-to-noise ratio SNR corresponding to each location point in the coverage area by the following formula:

Among them, EIRP is the effective isotropic radiation power emitted by the satellite; λ is the wavelength of the electromagnetic wave emitted by the satellite; d is the communication distance; B is the bandwidth of the satellite communication system; L _r is the receiving feed loss in the satellite communication system; L _other is the satellite communication system Other losses in ; G/T represents the terminal performance index; k=1.38×10 ^-23 is the Boltzmann constant.

Compared with the prior art, the solutions provided by the embodiments of the present application have the following beneficial effects:

1. In the scheme provided by the embodiment of this application, the satellite coverage area is first calculated, and then the estimated value of rain attenuation under the preset time availability is calculated, that is, the estimated value of rain attenuation in sunny or rainy days is calculated, and then the estimated value of rain attenuation is calculated according to the sunny day. Or the estimated value of rain attenuation under rainy days to calculate the SNR distribution probability in the coverage area, weight the spectral efficiency of multiple preset adaptive coding modulation methods according to the SNR distribution probability in the coverage area, and determine according to the principle of maximizing spectral efficiency. Adaptive coding and modulation with maximum spectral efficiency. The problem that the average spectral efficiency cannot be maximized due to the principle of increasing SNR at equal intervals is avoided, thereby improving the spectral efficiency.

2. In the solution provided by the embodiment of the present application, by calculating the actual coverage area of the satellite in combination with the actual orbit position of the satellite, and then calculating the SNR distribution in the actual coverage area of the satellite, the transmission performance of the designated system can be optimized in a targeted manner.

3. In the solution provided by the embodiment of the present application, by calculating the distribution of rain attenuation at different times of availability, and receiving SNR statistics for the selected availability, the system's ability to resist a certain degree of rain attenuation can be effectively improved. ability.

Description of drawings

1 is a schematic flowchart of a method for determining an adaptive coding and modulation mode for satellite communication provided by an embodiment of the present application;

2 is a schematic diagram of a satellite coverage area provided by an embodiment of the present application;

Fig. 3 is a kind of rain attenuation estimation value in the coverage area under the condition of availability at a given time provided by an embodiment of the application;

Fig. 4 is a kind of downlink receiving SNR calculation result under a given time availability condition provided by an embodiment of the present application;

Fig. 5a is the SNR probability distribution situation under a kind of sunny condition provided by the embodiment of the application;

Fig. 5b is the SNR probability distribution situation under a kind of rain attenuation condition provided by the embodiment of the application;

6 is a schematic diagram of an MCS for maximizing spectral efficiency provided by an embodiment of the present application;

FIG. 7 is a schematic structural diagram of an apparatus for determining an adaptive coding and modulation mode for satellite communication according to an embodiment of the present application.

Detailed ways

In the solutions provided in the embodiments of the present application, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

A method for determining an adaptive coding and modulation mode for satellite communication provided by the embodiments of the present application will be described in further detail below with reference to the accompanying drawings. The specific implementation of the method may include the following steps (the method flow is shown in FIG. 1 ):

Step 101: Calculate the coverage area of the satellite according to preset satellite ground parameter information, wherein the satellite ground parameter information includes satellite orbit height, earth radius, and longitude and latitude information of any location point on the earth.

Specifically, in the solution provided by the embodiment of the present application, there are various ways to calculate the coverage area of the satellite according to the preset satellite ground parameter information, and a preferred way is used as an example for description below.

In a possible implementation manner, calculating the coverage area of the satellite according to the preset satellite ground parameter information includes: calculating the threshold value of the pointing angle of the satellite antenna according to the satellite orbit height, the earth radius and the preset belief angle threshold value ; According to the satellite orbit height and the described longitude and latitude information, traversal and calculation obtain the first antenna pointing angle set of all position points on the earth; According to the threshold value, select the first antenna pointing angle set less than the threshold value from the first antenna pointing angle set Two sets of antenna pointing angles, and determine the area on the earth where the position point corresponding to each antenna pointing angle in the second antenna pointing angle set is located, and use the area as the coverage area.

Specifically, the threshold value of the pointing angle of the satellite antenna is obtained by calculating the following formula according to the known satellite orbit height, the earth radius and the preset belief angle threshold:

Among them, α represents the threshold of the pointing angle of the satellite antenna; _Re represents the satellite orbit height; σ represents the preset communication angle threshold; h represents the radius of the earth.

Further, according to the latitude and longitude coordinates (Lat, Lon) of any position point on the earth, calculate the satellite antenna pointing angle corresponding to any position point on the earth according to the following formula:

Among them, the pointing angle of the satellite antenna corresponding to any position point on the β earth; a and b respectively represent the distance vector between any position point and the satellite and the distance vector between any position point and the earth's center.

Further, since the satellite antenna pointing angle in the satellite coverage area satisfies the following conditions:

β＜α

According to the conditional traversal of the satellite antenna pointing angles in the satellite coverage area, the first antenna pointing angle set of all points on the earth is obtained, and the second antenna pointing angle set smaller than the threshold value is selected from the first antenna pointing angle set according to the threshold α. The antenna pointing angle is set, and the area on the earth where the position point corresponding to each antenna pointing angle in the second antenna pointing angle set is determined, and the area is used as the coverage area. Specifically, the calculated satellite coverage area is shown in FIG. 2 .

Step 102, under the preset time availability, calculate the estimated value of rain attenuation in the coverage area according to the preset rain attenuation estimation method, communication frequency and electromagnetic wave technology, wherein the preset time availability includes sunny days. and rainy days.

Specifically, in the satellite coverage area, according to the antenna pointing angle corresponding to each location point, the communication belief angle of the corresponding position is calculated, and then according to the rain attenuation estimation method recommended by the ITU standard, combined with the known communication frequency and electromagnetic wave polarization method, calculate Estimated value of rain attenuation within the coverage area for a given availability condition. Specifically, the estimated value of rain attenuation in the coverage area is shown in Figure 3.

Step 103: Under the preset time availability, perform satellite-ground link calculation according to the rain attenuation estimated value and preset communication information to obtain the terminal receiving signal-to-noise ratio SNR corresponding to each location point in the coverage area, And count the SNR distribution probability in the coverage area.

Specifically, in the solution provided by the embodiment of the present application, the preset communication information includes the effective isotropic radiated power (Effective lsotropic Radiated Power, EIRP) transmitted by the satellite, the wavelength λ of the electromagnetic wave transmitted by the satellite, the satellite communication distance d, the satellite The communication system bandwidth B, the receiving feed loss L _r of the satellite communication system, the other losses L _other of the satellite communication system, and the terminal performance index G/T. After calculating the estimated value of rain attenuation in the coverage area, the satellite-ground link will be calculated according to the estimated value of rain attenuation and the preset communication information to obtain the SNR received by the terminal corresponding to each location point in the coverage area, see Figure 4 Indicates the SNR distribution in a coverage area provided by the embodiment of the present application. Specifically, the signal-to-noise ratio SNR of the terminal corresponding to each location point in the coverage area is calculated by the following formula:

Among them, EIRP is the effective isotropic radiation power emitted by the satellite; λ is the wavelength of the electromagnetic wave emitted by the satellite; d is the communication distance; B is the bandwidth of the satellite communication system; L _r is the receiving feed loss in the satellite communication system; L _other is the satellite communication system Other losses in ; G/T represents the terminal performance index; k=1.38×10 ^-23 is the Boltzmann constant.

Further, after calculating the signal-to-noise ratio SNR of the terminal corresponding to each location point in the coverage area, the SNR distribution probability in the coverage area is calculated. Specifically, there are many ways to count the SNR distribution probability in the coverage area, and a preferred way is used as an example for description below.

In a possible implementation manner, calculating the SNR distribution probability in the coverage area includes: respectively determining the SNR corresponding to each location on sunny days and rainy days, and determining the SNR according to the corresponding SNRs on sunny days and rainy days. The SNR interval range corresponding to each location; the SNR distribution probability in the coverage area is obtained by performing statistics on each SNR value in the SNR interval range.

In order to counteract a certain degree of rain attenuation and at the same time improve the transmission efficiency of the system in sunny weather, the solution provided by the embodiment of the present application considers using interval statistics instead of fixed value statistics. The specific method is as follows, assuming that the receiving SNR of a certain position in the coverage area is S _sun on sunny days, and the receiving SNR on rainy days is S _rain , then in order to better combat the rain attenuation of the current availability and the smaller rain attenuation, it is necessary to measure the interval [S _rain , S _sun ] for all the values in the statistics, and finally get the statistical results in the coverage area. Specifically, referring to FIG. 5a, the SNR distribution probability in the coverage area under a sunny day condition provided by the embodiment of the present application; referring to FIG. 5b, the coverage area in the coverage area under the condition of 99.9% rain attenuation availability provided by the embodiment of the present application SNR distribution probability.

In the solution provided by the embodiment of the present application, by calculating the actual coverage area of the satellite in combination with the actual orbital position of the satellite, and then calculating the SNR distribution in the actual coverage area of the satellite, it is possible to optimize the transmission performance of the designated system in a targeted manner; and The distribution of rain attenuation under different time availability, and receiving SNR statistics for the selected availability can effectively improve the system's ability to resist a certain degree of rain attenuation.

Step 104: Determine an adaptive coding and modulation mode for satellite communication from a plurality of preset adaptive coding and modulation modes according to the SNR distribution probability.

In a possible implementation manner, determining an adaptive coding and modulation scheme for satellite communication from a plurality of preset adaptive coding and modulation schemes according to the SNR distribution probability includes: determining each of the adaptive coding and modulation schemes according to the SNR distribution probability. The spectral efficiency based on probability weighting corresponding to the preset adaptive coding and modulation mode; according to the spectral efficiency and the preset constraint conditions, the adaptive coding and modulation mode with the largest spectral efficiency is selected from the preset multiple adaptive coding and modulation modes A coding and modulation scheme is used, and the adaptive coding and modulation scheme with the maximum spectral efficiency is used as the satellite communication adaptive coding and modulation scheme.

Specifically, there are at least dozens of candidate coding and modulation schemes in the relevant protocols of the ACM technology, and the candidate coding and modulation schemes adopted in the solutions provided in the embodiments of the present application are 28 coding and modulation combinations in DVB-S2. By comparing the above-mentioned combined SNR threshold and spectral efficiency, it is found that the spectral efficiency of some coding and modulation methods is relatively low, but the required SNR threshold is higher. If this coding and modulation method is used, the system performance will be degraded. Therefore, according to the principle of monotonically increasing spectral efficiency and SNR threshold, the preliminary screening of the original combination is completed. In the solutions provided by the embodiments of the present application, it is known that N types of MCS are selected in the final solution, and the spectral efficiency of the ith MCS is defined as E _i and the SNR threshold is S _i , then the spectral efficiency of the ith MCS based on probability weighting is defined u _i can be expressed by the following formula:

where p(s) represents the probability density function; s represents the SNR.

Further, in a possible implementation manner, the preset constraint condition is expressed by the following formula:

Constraint C1:

其中，约束条件C1与C2分别为最小MCS间隔与最大MCS间隔约束；1≤i≤N。Constraint C2:

Among them, the constraints C1 and C2 are respectively the minimum MCS interval and the maximum MCS interval constraint; 1≤i≤N.

Specifically, the MCS optimization problem of maximizing spectral efficiency can be modeled as:

Constraint C1:

Constraint C2:

By solving the above optimization problem, the optimal MCS as shown in Figure 6 can be obtained.

In the solution provided by the embodiment of the present application, the satellite coverage area is first calculated, and then the estimated value of rain attenuation under the preset time availability is calculated, that is, the estimated value of rain attenuation in sunny or rainy days is calculated, and then the estimated value of rain attenuation is calculated on sunny or rainy days. Calculate the SNR distribution probability in the coverage area based on the estimated value of rain attenuation in the world, weight the spectral efficiency of multiple preset adaptive coding modulation methods according to the SNR distribution probability in the coverage area, and determine the spectral efficiency according to the principle of maximizing spectral efficiency The largest adaptive coding modulation method. The problem that the average spectral efficiency cannot be maximized due to the principle of increasing SNR at equal intervals is avoided, thereby improving the spectral efficiency.

Based on the same inventive concept as the method shown in FIG. 1 , an embodiment of the present application provides an apparatus for determining an adaptive coding and modulation mode for satellite communication. Referring to FIG. 7 , the apparatus includes:

The first calculation unit 701 is configured to calculate the coverage area of the satellite according to preset satellite ground parameter information, wherein the satellite ground parameter information includes satellite orbit height, earth radius, and latitude and longitude information of any position on the earth;

The second calculation unit 702 is configured to calculate the estimated value of rain attenuation in the coverage area according to the preset rain attenuation estimation method, communication frequency and electromagnetic wave technology under the preset time availability, wherein the preset rain attenuation estimation value is Time availability includes sunny and rainy days;

The statistical unit 703 is configured to perform satellite-ground link calculation according to the estimated rain attenuation value and the preset communication information under the preset time availability to obtain the terminal received signal noise corresponding to each location point in the coverage area Compare the SNR, and count the SNR distribution probability in the coverage area;

A determining unit 704, configured to determine a satellite communication adaptive coding and modulation mode from a plurality of preset adaptive coding and modulation modes according to the SNR distribution probability.

Optionally, the first computing unit 701 is specifically configured to:

The threshold value of the pointing angle of the satellite antenna is obtained by calculating according to the satellite orbit height, the earth radius and the preset belief angle threshold;

According to the satellite orbit height and the latitude and longitude information, the first antenna pointing angle set of all the position points on the earth is obtained through traversal calculation;

According to the threshold value, a second antenna pointing angle set smaller than the threshold value is selected from the first antenna pointing angle set, and it is determined that the position point corresponding to each antenna pointing angle in the second antenna pointing angle set is at The area where the earth is located, and the area is used as the coverage area.

Optionally, the statistics unit 703 is specifically used for:

Determine the SNR corresponding to each position in sunny and rainy days respectively, and determine the SNR interval range corresponding to each position according to the corresponding SNR in sunny and rainy days;

The SNR distribution probability in the coverage area is obtained by performing statistics on each SNR value in the SNR interval range.

Optionally, the determining unit 704 is specifically configured to:

Determine the spectral efficiency corresponding to each of the preset adaptive coding and modulation modes according to the SNR distribution probability;

According to the spectral efficiency and preset constraints As the satellite communication adaptive coding modulation method.

Optionally, the preset constraints are expressed by the following formula:

Constraint C1:

Constraint C2:

Among them, the constraints C1 and C2 are respectively the minimum MCS interval and the maximum MCS interval constraint; 1≤i≤N.

Optionally, calculating the signal-to-noise ratio SNR corresponding to each location point in the coverage area according to the estimated rain attenuation value and preset communication information, including:

Calculate the signal-to-noise ratio SNR corresponding to each location point in the coverage area by the following formula:

Among them, EIRP is the effective isotropic radiation power emitted by the satellite; λ is the wavelength of the electromagnetic wave emitted by the satellite; d is the communication distance; B is the bandwidth of the satellite communication system; L _r is the receiving feed loss in the satellite communication system; L _other is the satellite communication system Other losses in ; G/T represents the terminal performance index; k=1.38×10 ^-23 is the Boltzmann constant.

As will be appreciated by those skilled in the art, the embodiments of the present application may be provided as a method, a system, or a computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media having computer-usable program code embodied therein, including but not limited to disk storage, optical storage, and the like.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present application. It will be understood that each flow and/or block in the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to the processor of a general purpose computer, special purpose computer, embedded processor or other programmable data processing device to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing device produce Means for implementing the functions specified in a flow or flow of a flowchart and/or a block or blocks of a block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory result in an article of manufacture comprising instruction means, the instructions The apparatus implements the functions specified in the flow or flow of the flowcharts and/or the block or blocks of the block diagrams.

These computer program instructions can also be loaded on a computer or other programmable data processing device to cause a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process such that The instructions provide steps for implementing the functions specified in the flow or blocks of the flowcharts and/or the block or blocks of the block diagrams.

Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims (8)

1. A method for determining an adaptive coded modulation scheme for satellite communications, comprising:

calculating a coverage area of a satellite according to preset satellite parameter information, wherein the satellite parameter information comprises satellite orbit height, earth radius and longitude and latitude information of any position point on the earth;

under a preset time availability, calculating a rain attenuation estimation value in the coverage area according to a preset rain attenuation estimation method, a communication frequency and an electromagnetic wave technology mode, wherein the preset time availability comprises a sunny day and a rainy day;

under the preset time availability, carrying out satellite-ground link calculation according to the rain attenuation estimation value and preset communication information to obtain a terminal receiving signal-to-noise ratio (SNR) corresponding to each position point in the coverage area, and counting SNR distribution probability in the coverage area;

determining a satellite communication adaptive coding modulation mode from a plurality of preset adaptive coding modulation modes according to the SNR distribution probability;

calculating the coverage area of the satellite according to preset satellite parameter information, wherein the method comprises the following steps:

calculating to obtain a threshold value of a satellite antenna pointing angle according to the satellite orbit height, the earth radius and a preset communication elevation threshold value;

traversing and calculating according to the satellite orbit height and the longitude and latitude information to obtain a first antenna pointing angle set of all position points on the earth;

and selecting a second antenna pointing angle set smaller than the threshold value from the first antenna pointing angle set according to the threshold value, determining an area on the earth where a position point corresponding to each antenna pointing angle in the second antenna pointing angle set is located, and taking the area as the coverage area.

2. The method of claim 1, wherein the statistics of the probability of SNR distributions in the coverage area comprises:

respectively determining the SNR corresponding to each position in sunny days and rainy days, and determining the SNR interval range corresponding to each position according to the SNR corresponding to each position in sunny days and rainy days;

and counting each SNR value in the range of the SNR interval to obtain the SNR distribution probability in the coverage area.

3. The method of claim 2, wherein determining the adaptive modulation scheme for satellite communication from a plurality of preset adaptive modulation schemes according to the SNR distribution probability comprises:

determining probability-weighting-based spectrum efficiency corresponding to each preset adaptive coding modulation mode according to the SNR distribution probability;

and selecting the self-adaptive coding modulation mode with the maximum spectral efficiency from the preset multiple self-adaptive coding modulation modes according to the spectral efficiency and a preset constraint condition, and taking the self-adaptive coding modulation mode with the maximum spectral efficiency as the self-adaptive coding modulation mode for satellite communication.

4. The method of claim 3, wherein the preset constraint is expressed by the following formula:

constraint C1:

constraint C2:

the constraint conditions C1 and C2 are minimum MCS interval and maximum MCS interval constraints, respectively; i is more than or equal to 1 and less than or equal to N.

5. The method according to any one of claims 1 to 4, wherein calculating the SNR corresponding to each position point in the coverage area according to the rain fade estimation value and preset communication information comprises:

calculating the SNR of each position point in the coverage area according to the following formula:

wherein, EIRP represents the effective omnidirectional radiation power emitted by the satellite; λ represents the wavelength of the electromagnetic wave emitted by the satellite; d represents a communication distance; b represents a satellite communication system bandwidth; l is _r Representing the receive feed loss in a satellite communication system; l is a radical of an alcohol _other Represents other losses in the satellite communication system; G/T represents a terminal performance index; k is 1.38 × 10 ^-23 Boltzmann constant.

6. An apparatus for determining an adaptive coding modulation scheme for satellite communications, comprising:

the satellite positioning system comprises a first calculation unit, a second calculation unit and a positioning unit, wherein the first calculation unit is used for calculating a coverage area of a satellite according to preset satellite parameter information, and the satellite parameter information comprises satellite orbit height, earth radius and longitude and latitude information of any position point on the earth;

the second calculation unit is used for calculating the rain attenuation estimation value in the coverage area according to a preset rain attenuation estimation method, communication frequency and an electromagnetic wave technology mode under the preset time availability, wherein the preset time availability comprises sunny days and rainy days;

a statistic unit, configured to perform satellite-to-ground link calculation according to the rain attenuation estimation value and preset communication information to obtain a terminal received signal-to-noise ratio SNR corresponding to each location point in the coverage area under a preset time availability, and to count SNR distribution probability in the coverage area;

the determining unit is used for determining a satellite communication adaptive coding modulation mode from a plurality of preset adaptive coding modulation modes according to the SNR distribution probability;

the first computing unit is specifically configured to:

calculating to obtain a threshold value of a satellite antenna pointing angle according to the satellite orbit height, the earth radius and a preset communication elevation threshold value;

traversing and calculating according to the satellite orbit height and the longitude and latitude information to obtain a first antenna pointing angle set of all position points on the earth;

and selecting a second antenna pointing angle set smaller than the threshold value from the first antenna pointing angle set according to the threshold value, determining an area on the earth where a position point corresponding to each antenna pointing angle in the second antenna pointing angle set is located, and taking the area as the coverage area.

7. The apparatus of claim 6, wherein the statistics unit is specifically configured to:

respectively determining the SNR corresponding to each position in sunny days and rainy days, and determining the SNR interval range corresponding to each position according to the SNR corresponding to each position in sunny days and rainy days;

and counting each SNR value in the range of the SNR interval to obtain the SNR distribution probability in the coverage area.

8. The apparatus according to any one of claims 6 to 7, wherein the determining unit is specifically configured to:

determining probability-weighting-based spectrum efficiency corresponding to each preset adaptive coding modulation mode according to the SNR distribution probability;

and selecting the self-adaptive coding modulation mode with the maximum spectral efficiency from the preset multiple self-adaptive coding modulation modes according to the spectral efficiency and a preset constraint condition, and taking the self-adaptive coding modulation mode with the maximum spectral efficiency as the self-adaptive coding modulation mode for satellite communication.

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