Satellite communication method, device and satellite communication system

Abstract

The present application discloses a satellite communication method, device and satellite communication system, which relate to the field of satellite communication technology. The present application analyzes the establishment of communication connections between a user terminal and a satellite, and between a satellite and a target ground station, and determines that a correct communication connection has been established between the user terminal and the satellite, and between the satellite and the target ground station. The present application then encrypts the signal transmitted by the user terminal and transmits it to the satellite. At the same time, the strength of the signal received by the satellite in each channel and each unit time is analyzed, and then a channel that meets the requirements is selected for signal transmission. The signal strength of each channel at the end moment of the next unit time is predicted, and then the channel is adjusted to help the satellite receive the complete signal. Finally, the satellite sends the received signal to the target ground station for decryption and restoration to the original information.

Description

Technical Field

[0001] The present application relates to the field of satellite communication technology, and in particular to a satellite communication method, device and satellite communication system. Background Art

[0002] With the continuous development of society and technology, satellite communications have gradually been applied to various fields, and the security and stability of satellite communications are particularly important.

[0003] Prior art, such as the invention patent application with announcement number: CN107749773A, discloses a satellite communication system and a communication method thereof. The invention relates to a satellite communication system and a communication method thereof, wherein the space segment system is used to receive communication information from the ground segment system and send it to terminal users located in the Arctic / equatorial region; or receive communication information from terminal users in the Arctic / equatorial region and send it to the ground segment system; the ground segment system is used to receive communication information from ordinary users to terminal users in the Arctic / equatorial region, process and forward it to the space segment system; or receive communication information from the space segment system and forward it to ordinary users. Terminal users in the Arctic / equatorial region are users located in the Arctic / equatorial region who can communicate directly with the space segment system; ordinary users are users who communicate with the space segment system through the ground segment system. The present invention effectively covers the Arctic and the equator, and achieves multiple coverage of the above areas, thereby reducing satellite forwarding and delay.

[0004] With respect to the above-mentioned scheme, the inventors of the present application have found at least the following technical problems in the above-mentioned technology: 1. The current technology mainly realizes multiple coverage of the region, but lacks analysis of the communication connection status of each device in the system during satellite communication, and lacks establishment of exclusive communication connections for each device in the communication system, which is not conducive to improving the communication efficiency during satellite communication. At the same time, the system lacks encryption processing for the signals sent between the devices, which may cause the transmitted information to be stolen by a third party, and thus the security of the transmitted information cannot be guaranteed.

[0005] 1. Current technology lacks analysis of the strength of transmitted signals during operation. Signals may be lost excessively during transmission due to environmental or human factors. Therefore, there is no guarantee that the received signal is complete during satellite communication, and thus no guarantee that the transmitted information is correct. Furthermore, there is no prediction of the signal strength for the next unit of time. When an unexpected situation causes the signal strength to be too low, the satellite communication system cannot respond in a timely manner. Summary of the Invention

[0006] The purpose of this application is to provide a satellite communication method, device and satellite communication system to solve the problems existing in the background technology.

[0007] In order to solve the above technical problems, the present application adopts the following technical solutions: In the first aspect, the present application provides a satellite communication method, including: Step 1, user terminal signal transmission and processing: establishing a communication connection between the user terminal and the satellite, and encrypting the signal before transmitting it to the satellite.

[0008] Step 2: The satellite receives and analyzes the signal: The encrypted signal transmitted by the user terminal is processed and the signal bandwidth, transmission frequency and spatial path attenuation value are obtained. The signal strength assessment coefficient of each channel is then analyzed to determine whether the signal of each channel is complete, and the corresponding channel is selected for encrypted signal transmission.

[0009] Step 3: Signal strength prediction: Fit the signal strength evaluation coefficient of each channel into a signal change curve, and then predict the signal strength of each channel at the end time of the next unit time. Analyze whether to change the transmission channel based on the prediction results.

[0010] Step 4: Satellite transmits signal: Establish a communication connection between the satellite and the target ground station, and transmit an encrypted signal to the target ground station.

[0011] Step 5: The target ground station receives and analyzes the signal: Receives the encrypted signal transmitted by the satellite and decrypts it to restore it to the original information.

[0012] Preferably, the communication connection between the user terminal and the satellite is established in the following specific establishment process: the user terminal first sends a request number to the satellite, and at the same time the user terminal enters a monitoring state to monitor satellite information. After receiving the request number from the user terminal, the satellite returns a corresponding confirmation number to the user terminal. When the confirmation number received by the user terminal matches the request number sent by it, the communication connection between the user terminal and the satellite is established, and signal transmission is carried out between the user terminal and the satellite. Otherwise, the communication connection between the user terminal and the satellite is not completed, and signal transmission cannot be carried out between the user terminal and the satellite.

[0013] Preferably, the transmitted signal is encrypted, and the specific encryption process is as follows: the frequency and bandwidth of the signal per unit time of each channel transmitted by the user terminal are respectively recorded as F ij and P ij , i is the number of each channel, i = 1, 2 ... h, h is any integer greater than 2, h represents the total number of channels, j is the number of each unit time, j = 1, 2 ... f, f is an integer greater than 2, f represents the duration of the user terminal transmitting the signal, according to the radio frequency encryption, the frequency B is used to periodically modulate the transmitted signal of each channel and each unit time, and P ij >B, the frequency of the signal per unit time of each channel after modulation is F ij +kB, where k is an arbitrary integer, according to the calculation formula Get the periodic modulation signal function U of the signal of each channel per unit time ij , where e is a natural constant, π is the circumference of a circle, and g(t) is a phase function defined in the database for periodically modulating the signal. Different modulation modules, i.e., different g(t), are used to modulate the transmitted signal.

[0014] The original signal per unit time of each channel transmitted by the user terminal is recorded as S ij , according to the calculation formula: Get the encrypted signal S of each channel per unit time ij ′.

[0015] Preferably, the encrypted signal transmitted by the user terminal is processed, and the specific processing process is as follows: when the satellite receives the signal of each channel and each unit time transmitted by the user terminal, it uses the same modulation module as the user terminal to decrypt it, and the signal of each channel and each unit time after the spatial path attenuation is recorded as S ij ″, according to the calculation formula Get the original signal S of each channel per unit time after demodulation ij ,in It represents the attenuation coefficient of the signal transmitted from the user terminal to the satellite during space propagation, and ψ is the correction factor of the signal when the user terminal in the database communicates with the satellite.

[0016] Preferably, the signal strength evaluation coefficient of each channel is fitted into a signal change curve, and then the signal strength of each channel at the end of the next unit time is predicted, and whether to change the transmission channel is analyzed according to the prediction result. The specific fitting and prediction process is as follows: Obtain the coordinates of the signal strength endpoint And calculate the slope l,T i Indicates the end time of the unit time of the i-th channel, represents the signal strength evaluation coefficient of the i-th channel, where T i is the x-coordinate of the signal change curve, is the y coordinate of the signal change curve, according to the calculation formula Get the signal strength evaluation coefficient at the end of the next unit time

[0017] Compare the strength evaluation coefficient of the signal at the end moment of the next unit time with the strength evaluation coefficient threshold of the signal in the database. When the strength evaluation coefficient of the signal at the end moment of the next unit time is less than the strength evaluation coefficient threshold of the signal in the database, the transmission channel needs to be changed; otherwise, the transmission channel does not need to be changed.

[0018] Preferably, the communication connection between the satellite and the target ground station is established, and the specific establishment process is as follows: the satellite sends a request number to the target ground station, and the satellite enters a monitoring state to monitor the information of the target ground station. After receiving the request number from the satellite, the target ground station returns a corresponding confirmation number to the target ground station. When the confirmation number received by the satellite matches the request number it sent, the communication connection between the satellite and the target ground station is established, and signal transmission is carried out between the satellite and the target ground station. Otherwise, the connection between the satellite and the target ground station is not completed, and signal transmission cannot be carried out between the satellite and the target ground station.

[0019] Preferably, the encrypted signal transmitted by the receiving satellite is decrypted and restored to the original information, and the same modulation module as the encryption process is used to perform the inverse operation of the encryption process, and the signal after the space path attenuation is recorded as S' ij , according to the calculation formula Get the original signal function S after demodulation ij , where β represents the attenuation coefficient of the signal transmitted from the satellite to the target ground station during space propagation set in the database, and σ is the correction factor of the signal during satellite communication in the database.

[0020] In a second aspect, the present application provides a device for satellite communication, applying a satellite communication method, characterized in that: the device for satellite communication includes a user terminal, a satellite and a target ground station; the user terminal, the satellite and the target ground station implement the steps in a satellite communication method.

[0021] In a third aspect, the present application provides a satellite communication system, including: user terminal signal transmission and processing: establishing a communication connection between the user terminal and the satellite, and encrypting the signal before transmitting it to the satellite.

[0022] The satellite receives and analyzes the signal: it processes the encrypted signal transmitted by the user terminal and obtains the signal bandwidth, transmission frequency and spatial path attenuation value, and then analyzes and obtains the signal strength assessment coefficient of each channel, determines whether the signal of each channel is complete, and selects the corresponding channel for encrypted signal transmission.

[0023] Signal strength prediction: The signal strength of each channel is fitted into a signal change curve, and the signal strength of each channel in the next unit time is predicted. Based on the prediction results, it is analyzed whether to change the transmission channel.

[0024] Satellite transmits signal: establishes a communication connection between the satellite and the target ground station, and transmits an encrypted signal to the target ground station.

[0025] The target ground station receives and analyzes the signal: it receives the encrypted signal transmitted by the satellite and decrypts it to restore it to the original information.

[0026] The beneficial effects of the present application are: 1. A satellite communication method, device and satellite communication system provided by the present application analyzes the establishment of communication connections between the user terminal and the satellite, and between the satellite and the target ground station, determines that a correct communication connection has been established between the user terminal and the satellite, and between the satellite and the target ground station, and then encrypts the signal transmitted by the user terminal and transmits it to the satellite. At the same time, the strength of the signal received by the satellite on each channel per unit time is analyzed, and then a channel that meets the requirements is selected for signal transmission. The signal strength of each channel at the end moment of the next unit time is predicted, and then the channel is adjusted to help the satellite receive the complete signal. Finally, the satellite sends the received signal to the target ground station for decryption and restoration to the original information.

[0027] 2. This application first analyzes the establishment of communication connections between user terminals and satellites, and between satellites and target ground stations during satellite communications, thereby ensuring that signals can be reliably transmitted and received, while also greatly improving the efficiency of satellite communications. The application then analyzes the encryption of signals transmitted during satellite communications to ensure that information transmitted through signals will not be stolen by third parties, thereby ensuring the security and reliability of information during satellite communications, and enabling satellite communications to be carried out safely and stably.

[0028] 3. This application analyzes the signal strength of each channel received by the satellite at each unit time, and then selects the channel with the required strength for signal transmission, thereby ensuring the integrity of the signal transmitted during satellite communication and the accuracy of the transmitted information, thereby greatly improving the user experience.

[0029] 4. The present application predicts the signal strength of each channel at the end moment of the next unit time, and changes the transmission channel in time according to the prediction result to prevent the problem of information loss caused by incomplete signals, thereby ensuring the integrity of the signal transmitted during satellite communication and improving the signal transmission efficiency, thereby ensuring the communication quality between various devices during satellite communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0031] Figure 1 Flowchart of the steps for implementing the application method.

[0032] Figure 2 This is a schematic diagram of the device structure of this application.

[0033] Figure 3 This is a schematic diagram of the connection of each module in this application. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0035] Reference Figure 1 As shown, the present application provides a satellite communication method, comprising the following steps: Step 1, user terminal signal transmission and processing: establishing a communication connection between the user terminal and the satellite, and encrypting the signal before transmitting it to the satellite.

[0036] In a specific example, the communication connection between the user terminal and the satellite is established through the following process: the user terminal first sends a request number to the satellite, and at the same time, the user terminal enters a listening state to listen to satellite information. After receiving the request number from the user terminal, the satellite returns a corresponding confirmation number to the user terminal. When the confirmation number received by the user terminal matches the request number it sent, the communication connection between the user terminal and the satellite is established, and signal transmission is carried out between the user terminal and the satellite. Otherwise, the communication connection between the user terminal and the satellite is not completed, and signal transmission cannot be carried out between the user terminal and the satellite.

[0037] It should be noted that the request number and confirmation number are signs to ensure that the signal can be transmitted correctly. The prerequisite for the user terminal to establish a connection with the satellite is that the request number sent by the user terminal matches the confirmation number returned by the satellite. For example, if the request number sent by the user terminal is a seven-bit binary number, when the confirmation number returned by the satellite is the complement of the seven-bit binary number, the confirmation number received by the user terminal matches the request number it sent. Otherwise, the confirmation number received by the user terminal does not match the request number it sent.

[0038] In a specific example, the encryption process of the transmitted signal is as follows: the frequency and bandwidth of the signal of each channel and each unit time transmitted by the user terminal are respectively recorded as F ij and P ij, i is the number of each channel, i = 1, 2 ... h, h is any integer greater than 2, h represents the total number of channels, j is the number of each unit time, j = 1, 2 ... f, f is an integer greater than 2, f represents the duration of the user terminal transmitting the signal, according to the radio frequency encryption, the frequency B is used to periodically modulate the transmitted signal of each channel and each unit time, and P ij >B, the frequency of the signal per unit time of each channel after modulation is F ij +kB, where k is an arbitrary integer, according to the calculation formula Get the periodic modulation signal function U of the signal of each channel per unit time ij , where e is a natural constant, π is the circumference of a circle, and g(t) is a phase function defined in the database for periodically modulating the signal. Different modulation modules, i.e., different g(t), are used to modulate the transmitted signal.

[0039] The original signal per unit time of each channel transmitted by the user terminal is recorded as S ij , according to the calculation formula: Get the encrypted signal S of each channel per unit time ij ′.

[0040] It should be noted that the use of the phase function g(t) to periodically modulate the signal is to encrypt the signal by changing the frequency or phase of the function. For example, when the modulation module encrypts the signal by changing the phase, within a period T, the phase of the modulation module in the interval [t1, t2] is 0°, and the phase of the rest of the time is 180°, then Where t1 and t2 represent the start and end times of the periodic modulation, respectively, and t is the time when the user terminal transmits the signal.

[0041] It should be noted that when P ij When >B, the signal spectrum generated after modulation will be aliased, thereby causing the signal to be encrypted.

[0042] Step 2: The satellite receives and analyzes the signal: The encrypted signal transmitted by the user terminal is processed and the signal bandwidth, transmission frequency and spatial path attenuation value are obtained. The signal strength assessment coefficient of each channel is then analyzed to determine whether the signal of each channel is complete, and the corresponding channel is selected for encrypted signal transmission.

[0043] In a specific example, the encrypted signal transmitted by the user terminal is processed as follows: when the satellite receives the signal of each channel and each unit time sent by the user terminal, it uses the same modulation module as the user terminal to decrypt it, and the signal of each channel and each unit time after spatial path attenuation is recorded as S ij ″, according to the calculation formula Get the original signal S of each channel per unit time after demodulation ij ,in It represents the attenuation coefficient of the signal transmitted from the user terminal to the satellite during space propagation, and ψ is the correction factor of the signal when the user terminal in the database communicates with the satellite.

[0044] It should be noted that spatial path attenuation refers to the phenomenon of signal strength degradation caused by the signal passing through the atmosphere, clouds and terrain during transmission.

[0045] It should be noted that

[0046] It should be noted that the attenuation coefficient of the signal transmitted from the user terminal to the satellite during space propagation set in the database is the average value obtained by removing the maximum and minimum values from the ratio of the received power to the transmitted power of the signal of each channel and each unit time transmitted by the user terminal.

[0047] It should be noted that 0<ψ<1.

[0048] It should be noted that the factor correction method is a well-known technology. The correction factor corresponding to the signal strength evaluation coefficient of each channel per unit time is obtained through the correction factor analysis method. First, the original data of the signal strength of each channel per unit time is obtained, and the average value is taken after removing the maximum and minimum values. Then, the correction factor is obtained by dividing the original data of the signal strength of each channel per unit time by the median after removing the maximum and minimum values.

[0049] In a specific example, the analysis obtains the signal strength evaluation coefficient of each channel per unit time and determines whether the signal of each channel is complete. The specific analysis and judgment process is as follows: the transmission frequency, bandwidth and spatial path attenuation value of the signal per unit time of each channel when the user terminal transmits are respectively recorded as M ij 、N ij and S ij , according to the calculation formula: Get the signal strength evaluation coefficient η of each channel per unit time ij , where M′, N′, and S′ represent the standard value of the transmission frequency, bandwidth, and spatial path attenuation of the signal in the database, respectively; ζ1, ζ2, and ζ3 represent the weight factors corresponding to the bandwidth, transmission frequency, and spatial path attenuation of the signal in the database, respectively.

[0050] The signal strength evaluation coefficient of each channel per unit time is compared with the signal strength evaluation coefficient threshold in the database. When the signal strength evaluation coefficient of a certain channel per unit time is less than the signal strength evaluation coefficient threshold in the database, it is judged that the signal transmitted by the channel per unit time is incomplete, and the channel is not used to transmit the encrypted signal. Otherwise, it is judged that the signal transmitted by the channel per unit time is complete, and the channel is used to transmit the encrypted signal.

[0051] It should be noted that the transmission frequency of the signal of each channel per unit time refers to the number of times the user terminal transmits the signal per unit time, the bandwidth of the signal of each channel per unit time refers to the spectrum width occupied by the signal of each channel per unit time, and the spatial path attenuation value of the signal of each channel per unit time refers to the difference between the transmission power and the reception power of the signal of each channel per unit time.

[0052] It should be noted that the standard value of the signal transmission frequency in the database is the signal transmission frequency corresponding to when the signal received by the satellite is complete and has the maximum strength; the standard value of the signal bandwidth in the database is the signal bandwidth corresponding to when the signal received by the satellite is complete and has the maximum strength; the standard value of the spatial path attenuation of the signal in the database is the minimum value of the spatial path attenuation of the signal among all complete signals received by the satellite.

[0053] It should be noted that 0<ζ1<1, 0<ζ2<1, 0<ζ3<1, ζ1+ζ2+ζ3=1.

[0054] It should be noted that the factor analysis method is used to obtain the weight factors corresponding to the transmission frequency of the signal per unit time of each channel, the weight factors corresponding to the bandwidth, and the weight factors corresponding to the path loss in free space during signal transmission. First, the information of the signal transmission frequency, bandwidth, and spatial path attenuation is condensed, and then the variance explanation rate after rotation is obtained. The weight is obtained by dividing the cumulative variance explanation rate.

[0055] It should be noted that factor analysis is a well-known technology. It is a multivariate statistical analysis method that starts from studying the internal dependencies of variables and reduces some variables with complex relationships to a few comprehensive factors; information concentration is expressed as calculating the median; the variance explanation rate is the amount of information extracted by the factor, and the variance explanation rate = characteristic root / total number of analysis items; the variance explanation rate after rotation is expressed as the variance explanation rate of the factor after maximum variance rotation.

[0056] It should be noted that the signal strength evaluation coefficient threshold in the database is represented by the minimum value of the signal strength evaluation coefficient corresponding to when the signal received by the satellite is complete and no longer changes within a unit time.

[0057] Step 3: Signal strength prediction: Fit the signal strength evaluation coefficients of each channel into a signal change curve, and then predict the signal strength of each channel at the end of the next unit time. Analyze whether to change the transmission channel based on the prediction results.

[0058] In a specific example, the signal strength evaluation coefficient of each channel is fitted into a signal change curve, and then the signal strength of each channel at the end of the next unit time is predicted. According to the prediction result, whether to change the transmission channel is analyzed. The specific fitting and prediction process is as follows: Get the coordinates of the signal strength endpoint And calculate the slope l,T i Indicates the end time of the unit time of the i-th channel, represents the signal strength evaluation coefficient of the i-th channel, where T i is the x-coordinate of the signal change curve, is the y coordinate of the signal change curve, according to the calculation formula Get the signal strength evaluation coefficient at the end of the next unit time

[0059] Compare the strength evaluation coefficient of the signal at the end moment of the next unit time with the strength evaluation coefficient threshold of the signal in the database. When the strength evaluation coefficient of the signal at the end moment of the next unit time is less than the strength evaluation coefficient threshold of the signal in the database, the transmission channel needs to be changed; otherwise, the transmission channel does not need to be changed.

[0060] Step 4: Satellite transmits signal: Establish a communication connection between the satellite and the target ground station, and transmit an encrypted signal to the target ground station.

[0061] In a specific example, the communication connection between the satellite and the target ground station is established, and the specific establishment process is as follows: the satellite sends a request number to the target ground station, and the satellite enters a monitoring state to monitor the information of the target ground station. After receiving the request number from the satellite, the target ground station returns a corresponding confirmation number to the target ground station. When the confirmation number received by the satellite matches the request number it sent, the communication connection between the satellite and the target ground station is established, and signals are transmitted between the satellite and the target ground station. Otherwise, the connection between the satellite and the target ground station is not completed, and signals cannot be transmitted between the satellite and the target ground station.

[0062] It should be noted that the request number and confirmation number are signs to ensure that the signal can be transmitted correctly. The prerequisite for the satellite to establish a connection with the target ground station is that the request number sent by the satellite matches the confirmation number returned by the target ground station. For example, if the request number sent by the satellite is a seven-bit binary number, when the confirmation number returned by the target ground station is the complement of the seven-bit binary number, the confirmation number received by the satellite matches the request number it sent. Otherwise, the confirmation number received by the satellite does not match the request number it sent.

[0063] Step 5: The target ground station receives and analyzes the signal: Receives the encrypted signal transmitted by the satellite and decrypts it to restore it to the original information.

[0064] In a specific example, the encrypted signal transmitted by the receiving satellite is decrypted and restored to the original information, and the same modulation module as the encryption process is used to perform the inverse operation of the encryption process, and the signal after the space path attenuation is recorded as S' ij , according to the calculation formula Get the original signal function S after demodulation ij , where β represents the attenuation coefficient of the signal transmitted from the satellite to the target ground station during space propagation set in the database, and σ is the correction factor of the signal during satellite communication in the database.

[0065] It should be noted that 0<β<1.

[0066] It should be noted that the attenuation coefficient of the signal transmitted by the satellite to the user terminal during space propagation set in the database is the average value obtained by removing the maximum and minimum values from the ratio of the received power to the transmitted power of the signal per unit time in each channel transmitted by the satellite.

[0067] It should be noted that 0<σ<1.

[0068] It should be noted that the factor correction method is a well-known technology. The correction factor corresponding to the satellite communication signal is obtained by the correction factor analysis method. First, the original data of the satellite communication signal is obtained, and the average value is taken after removing the maximum and minimum values. The correction factor is then divided by the median of the original data of each satellite communication signal after removing the maximum and minimum values to obtain the correction factor.

[0069] Reference Figure 2 As shown, the present application provides a device for satellite communication in the second aspect, applying a satellite communication method, characterized in that: the device for satellite communication includes a user terminal, a satellite and a target ground station; the user terminal, the satellite and the target ground station implement the steps in a satellite communication method.

[0070] Reference Figure 3As shown, the present application provides a satellite communication system in a third aspect for executing a satellite communication method, characterized in that it includes: user terminal signal transmission and processing: establishing a communication connection between the user terminal and the satellite, and encrypting the signal before transmitting it to the satellite.

[0071] The satellite receives and analyzes the signal: it processes the encrypted signal transmitted by the user terminal and obtains the signal bandwidth, transmission frequency and spatial path attenuation value, and then analyzes and obtains the signal strength assessment coefficient of each channel, determines whether the signal of each channel is complete, and selects the corresponding channel for encrypted signal transmission.

[0072] Signal strength prediction: The signal strength of each channel is fitted into a signal change curve, and the signal strength of each channel in the next unit time is predicted. Based on the prediction results, it is analyzed whether to change the transmission channel.

[0073] Satellite transmits signal: establishes a communication connection between the satellite and the target ground station, and transmits an encrypted signal to the target ground station.

[0074] The target ground station receives and analyzes the signal: it receives the encrypted signal transmitted by the satellite and decrypts it to restore it to the original information.

[0075] The present application provides a satellite communication method, device and satellite communication system, which analyzes the establishment of communication connections between a user terminal and a satellite, and between a satellite and a target ground station, and determines that a correct communication connection has been established between the user terminal and the satellite, and between the satellite and the target ground station. Then, the signal transmitted by the user terminal is encrypted and transmitted to the satellite. At the same time, the strength of the signal received by the satellite on each channel per unit time is analyzed, and a channel that meets the requirements is selected for signal transmission. The signal strength of each channel at the end moment of the next unit time is predicted, and the channel is adjusted to help the satellite receive the complete signal. Finally, the satellite sends the received signal to the target ground station for decryption and restoration to the original information.

[0076] The above content is merely an example and explanation of the concept of the present application. Technicians in this technical field may make various modifications or additions to the described specific embodiments or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined in this application, they should all fall within the scope of protection of this application.

Claims

1. A satellite communication method, characterized in that: The steps include: Step 1: User terminal signal transmission and processing: Establish a communication connection between the user terminal and the satellite, and encrypt the signal before transmitting it to the satellite; Step 2: The satellite receives and analyzes the signal: The satellite processes the encrypted signal transmitted by the user terminal and obtains the signal bandwidth, transmission frequency, and spatial path attenuation value. The satellite then analyzes and derives the signal strength assessment coefficient of each channel, determines whether the signal of each channel is complete, and selects the corresponding channel for encrypted signal transmission. Step 3: Signal strength prediction: Fit the signal strength evaluation coefficients of each channel into a signal change curve, and then predict the signal strength of each channel at the end of the next unit time. Based on the prediction results, analyze whether to change the transmission channel; The signal strength evaluation coefficients of each channel are fitted into a signal change curve, and then the signal strength of each channel at the end of the next unit time is predicted. The process is as follows: Get signal strength endpoint coordinates and calculate the slope , Indicates the The end time of the unit time of each channel, Indicates the The signal strength evaluation coefficient of the channel is The signal change curve coordinate, The signal change curve Coordinates, according to the calculation formula Get the signal strength evaluation coefficient at the end of the next unit time ; Step 4: Satellite transmits signal: Establishes a communication connection between the satellite and the target ground station, and transmits an encrypted signal to the target ground station; Step 5: The target ground station receives and analyzes the signal: Receives the encrypted signal transmitted by the satellite and decrypts it to restore it to the original information.

2. A satellite communication method according to claim 1, characterized in that: The communication connection between the user terminal and the satellite is established in the following specific process: The user terminal first sends a request number to the satellite, and at the same time the user terminal enters the monitoring state to monitor satellite information. After receiving the request number from the user terminal, the satellite returns a corresponding confirmation number to the user terminal. When the confirmation number received by the user terminal matches the request number it sent, the communication connection between the user terminal and the satellite is established, and signal transmission is carried out between the user terminal and the satellite. Otherwise, the communication connection between the user terminal and the satellite is not completed, and signal transmission cannot be carried out between the user terminal and the satellite.

3. A satellite communication method according to claim 2, characterized in that: The signal is encrypted, and the specific encryption process is as follows: The frequency and bandwidth of the signal per unit time of each channel transmitted by the user terminal are respectively recorded as and , is the number of each channel, , is any integer greater than 2, Indicates the total number of channels, is the number of each unit time, , is an integer greater than 2, Indicates the duration of the user terminal transmitting the signal, which is encrypted in frequency according to the radio frequency. The transmitted signals of each channel and each unit time are modulated periodically, and , the frequency of the signal per unit time of each channel after modulation is ,in is any integer, according to the calculation formula Get the periodic modulation signal function of the signal of each channel per unit time ,in is a natural constant, is pi, The phase function of periodic modulation of the signal defined in the database uses different modulation modules, that is, different Modulating the transmit signal; The original signal per unit time of each channel transmitted by the user terminal is recorded as , according to the calculation formula: Get the encrypted signal of each channel per unit time .

4. A satellite communication method according to claim 3, characterized in that: The encrypted signal transmitted by the user terminal is processed, and the specific processing process is as follows: When the satellite receives the signal of each channel per unit time sent by the user terminal, it uses the same modulation module as the user terminal to decrypt it, and records the signal of each channel per unit time after the spatial path attenuation as , according to the calculation formula Get the original signal of each channel per unit time after demodulation ,in It represents the attenuation coefficient of the signal transmitted from the user terminal to the satellite during space propagation, It is the correction factor of the signal when the user terminal in the database communicates with the satellite.

5. A satellite communication method according to claim 4, characterized in that: The analysis obtains the signal strength evaluation coefficient of each channel per unit time, and determines whether the signal of each channel is complete. The specific analysis and judgment process is as follows: The transmission frequency, bandwidth and spatial path attenuation value of the signal per unit time of each channel when the user terminal transmits are recorded as 、 and , according to the calculation formula: Get the signal strength evaluation coefficient of each channel per unit time ,in 、 and They represent the standard values of the transmission frequency, bandwidth and spatial path attenuation of the signals in the database respectively. 、 and Respectively represent the weight factor corresponding to the bandwidth of the signal in the database, the weight factor corresponding to the transmission frequency, and the weight factor corresponding to the spatial path attenuation value; The signal strength evaluation coefficient of each channel per unit time is compared with the signal strength evaluation coefficient threshold in the database. When the signal strength evaluation coefficient of a certain channel per unit time is less than the signal strength evaluation coefficient threshold in the database, it is judged that the signal transmitted by the channel per unit time is incomplete, and the channel is not used to transmit the encrypted signal. Otherwise, it is judged that the signal transmitted by the channel per unit time is complete, and the channel is used to transmit the encrypted signal.

6. A satellite communication method according to claim 5, characterized in that: The specific process of analyzing whether to change the transmission channel based on the prediction result is as follows: Compare the strength evaluation coefficient of the signal at the end moment of the next unit time with the strength evaluation coefficient threshold of the signal in the database. When the strength evaluation coefficient of the signal at the end moment of the next unit time is less than the strength evaluation coefficient threshold of the signal in the database, the transmission channel needs to be changed; otherwise, the transmission channel does not need to be changed.

7. A satellite communication method according to claim 6, characterized in that: The communication connection between the satellite and the target ground station is established in the following specific process: The satellite sends a request number to the target ground station, and at the same time the satellite enters the monitoring state to monitor the information of the target ground station. After receiving the request number from the satellite, the target ground station returns a corresponding confirmation number to the target ground station. When the confirmation number received by the satellite matches the request number it sent, the communication connection between the satellite and the target ground station is established, and signal transmission is carried out between the satellite and the target ground station. Otherwise, the connection between the satellite and the target ground station is not completed, and signal transmission cannot be carried out between the satellite and the target ground station.

8. A satellite communication method according to claim 7, characterized in that: The encrypted signal transmitted by the receiving satellite is decrypted and restored to the original information. The same modulation module as the encryption process is used to perform the inverse operation of the encryption process. The signal after the space path attenuation is recorded as , according to the calculation formula Get the original signal after demodulation ,in It represents the attenuation coefficient of the signal transmitted from the satellite to the target ground station during space propagation, is the correction factor of the satellite communication signal in the database.

9. A device for satellite communication, applying a satellite communication method according to any one of claims 1 to 8, characterized in that: The device for satellite communication includes a user terminal, a satellite and a target ground station; the user terminal, the satellite and the target ground station implement the steps in a satellite communication method as described in any one of claims 1-8.

10. A satellite communication system, configured to execute a satellite communication method according to any one of claims 1 to 8, characterized in that: include: User terminal signal transmission and processing: establishes a communication connection between the user terminal and the satellite, and encrypts the signal before transmitting it to the satellite; Satellite receives and analyzes signals: It processes the encrypted signals transmitted by the user terminal and obtains the signal bandwidth, transmission frequency, and spatial path attenuation value. It then analyzes and derives the signal strength assessment coefficient of each channel, determines whether the signal of each channel is complete, and selects the corresponding channel for encrypted signal transmission; Signal strength prediction: Fit the signal strength of each channel into a signal change curve, and then predict the signal strength of each channel in the next unit time. Based on the prediction results, analyze whether to change the transmission channel; The signal strength evaluation coefficients of each channel are fitted into a signal change curve, and then the signal strength of each channel at the end of the next unit time is predicted. The process is as follows: Get signal strength endpoint coordinates and calculate the slope , Indicates the The end time of the unit time of each channel, Indicates the The signal strength evaluation coefficient of the channel is The signal change curve coordinate, The signal change curve Coordinates, according to the calculation formula Get the signal strength evaluation coefficient at the end of the next unit time ; Satellite signal transmission: establishes a communication connection between the satellite and the target ground station, and transmits an encrypted signal to the target ground station; The target ground station receives and analyzes the signal: it receives the encrypted signal transmitted by the satellite and decrypts it to restore it to the original information.

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