Satellite communication method, satellite communication device and satellite communication system

Abstract

The invention discloses a satellite communication method and device and a satellite communication system, and relates to the technical field of satellite communication, and the method comprises the steps: analyzing the establishment conditions of communication connection between a user terminal and a satellite, and between the satellite and a target ground station, and determining the user terminal and the satellite; and after correct communication connection is established between the satellite and the target ground station, encrypting the signal transmitted by the user terminal and transmitting the signal to the satellite, and analyzing the strength condition of the signal of each channel in each unit time received by the satellite, so as to select the channel meeting the requirement for signal transmission. The signal intensity of the next unit time end moment of each channel is predicted, then the channels are adjusted to help a satellite to receive complete signals, and finally the satellite sends the received signals to a target ground station to decrypt and restore the signals into 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 are gradually being applied to various fields. If the satellite communication process is not secure enough, the user's private information will be maliciously stolen, commercial information will be leaked, and even national security will be threatened. Therefore, the security and stability of satellite communications are particularly important.

[0003] Prior art, such as the invention application patent 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 regions, thereby reducing satellite forwarding and delay.

[0004] With respect to the above scheme, the inventors of the present application have at least discovered that the above technology has at least the following technical problems: 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 signals sent between 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. The current technology lacks analysis of the strength of the transmitted signal during operation. The signal may be lost too much during transmission due to environmental or human factors. At this time, it is impossible to guarantee whether the received signal during satellite communication is complete, and thus it is impossible to guarantee whether the transmitted information is correct. At the same time, there is a lack of prediction of the signal strength in the next unit time. When an unexpected situation occurs and the signal strength is too low, the satellite communication system cannot respond in time. Summary of the invention

[0006] The purpose of the present 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, and then the signal strength evaluation coefficient of each channel is analyzed to determine whether the signal of each channel is complete, and the corresponding channel is selected for the transmission of the encrypted signal.

[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, and 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, and the specific establishment process is as follows: 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 performed 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 performed 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 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, based on the RF encryption 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 the circumference of a circle, The phase function of periodic modulation of the signal defined in the database uses different modulation modules, that is, different Modulate the transmit signal.

[0014] 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 .

[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 records the signal of each channel and each 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 is represented by the attenuation coefficient of the signal transmitted from the user terminal to the satellite during space propagation set in the database. It 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 time 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 signal strength endpoint coordinates And calculate the slope , Indicates The end time of the unit time of the channel, Indicates 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 .

[0017] The strength evaluation coefficient of the signal at the end moment of the next unit time is compared 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 sent by it, 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.

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

[0020] In a second aspect, the present application provides a device for satellite communication, applying a method for satellite communication as described in any one of claims 1-8, 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 the satellite communication method as described in any one of claims 1-8.

[0021] The present application provides a satellite communication system in a third aspect, 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 the transmission of the encrypted signal.

[0023] 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, and analyze whether to change the transmission channel based on the prediction results.

[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 as follows: 1. A satellite communication method, device and satellite communication system provided by the present application analyzes the establishment of the communication connection 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 per unit time of each channel received by the satellite is analyzed, and then a channel that meets the requirements is selected for signal transmission, and then 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 encryption of signals transmitted during satellite communications is then analyzed 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, while enabling satellite communications to be conducted 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 strength that meets the requirements 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 time of the next unit time, and promptly changes the transmission channel according to the prediction result to prevent the problem of missing information due to incomplete signals, thereby ensuring the integrity of the signal transmitted during satellite communication and improving the transmission efficiency of the signal, thereby ensuring the communication quality between 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 drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 paying creative work.

[0031] Figure 1 The present invention is a flowchart of the steps for implementing the present 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 the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work 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, and the specific establishment process is as follows: 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 performed 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 performed 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 premise 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 sent by it, otherwise the confirmation number received by the user terminal does not match the request number sent by it.

[0038] In a specific example, the encryption process of the transmitted signal 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, based on the RF encryption 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 the circumference of a circle, The phase function of periodic modulation of the signal defined in the database uses different modulation modules, that is, different Modulate the transmit signal.

[0039] 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 .

[0040] It should be noted that the use of phased functions Periodic modulation of a signal is performed by changing the frequency or phase of a function to encrypt the signal. For example, when the modulation module encrypts the signal by changing the phase, In the interval, the modulation module The phase is 0° during the period of time and 180° at other times. ,in and Respectively represent the start and end time of periodic modulation, The time when the user terminal transmits the signal.

[0041] It should be noted that when When the modulation signal is aliased, the spectrum of the signal generated will be aliased, thus encrypting the signal.

[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, and then the signal strength evaluation coefficient of each channel is analyzed to determine whether the signal of each channel is complete, and the corresponding channel is selected for the transmission of the encrypted signal.

[0043] In a specific example, 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 , according to the calculation formula Get the original signal of each channel per unit time after demodulation ,in It is represented by the attenuation coefficient of the signal transmitted from the user terminal to the satellite during space propagation set in the database. It 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 decrease 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 per unit time transmitted by the user terminal.

[0047] It should be noted that .

[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 by 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. The correction factor is then 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 of each channel per unit time 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 value of the transmission frequency, bandwidth and spatial path attenuation of the signal in the database respectively. , and They 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.

[0050] The signal strength assessment coefficient of each channel per unit time is compared with the signal strength assessment coefficient threshold in the database. When the signal strength assessment coefficient of a channel per unit time is less than the signal strength assessment 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 encrypted signals. Otherwise, it is judged that the signal transmitted by the channel per unit time is complete, and the channel is used to transmit encrypted signals.

[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 transmission frequency of the signal corresponding to when the signal received by the satellite is complete and has the maximum strength; the standard value of the bandwidth of the signal in the database is the bandwidth of the signal 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 , , , .

[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, and 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 intricate 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 value 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 does not change within a unit time.

[0057] 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 of the next unit time, and 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 time 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: Get the signal strength endpoint coordinates And calculate the slope , Indicates The end time of the unit time of the channel, Indicates 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 .

[0059] The strength evaluation coefficient of the signal at the end moment of the next unit time is compared 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 premise 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 inverse operation of the encryption process is performed using the same modulation module as the encryption process, and the signal after the space path attenuation is recorded as , according to the calculation formula Get the original signal function after demodulation ,in It is expressed as the attenuation coefficient of the signal transmitted from the satellite to the target ground station set in the database during space propagation. is the correction factor of the satellite communication signal in the database.

[0065] It should be noted that .

[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 of each channel per unit time transmitted by the satellite.

[0067] It should be noted that .

[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, in a second aspect, a device for satellite communication, applying a method for satellite communication as described in any one of claims 1-8, 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.

[0070] Reference Figure 3 As shown, the present application provides a satellite communication system in a third aspect, for executing a satellite communication method as described in claims 1-8, 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 the transmission of the encrypted signal.

[0072] 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, and analyze whether to change the transmission channel based on the prediction results.

[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, 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 per unit time of each channel received by the satellite 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.

[0076] The above contents are merely examples and explanations of the concept of the present application. The 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 the present application, they should all fall within the protection scope of the present 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 encrypted signal transmitted by the user terminal is processed and the bandwidth, transmission frequency and spatial path attenuation value of the signal are obtained, and then the strength evaluation coefficient of the signal of each channel is analyzed to determine whether the signal of each channel is complete, and the corresponding channel is selected for the transmission of the encrypted signal; 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, and analyze whether to change the transmission channel based on the prediction result; 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 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 denoted 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, based on the RF encryption 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 the circumference of a circle, The phase function of periodic modulation of the signal defined in the database uses different modulation modules, that is, different Modulating the transmitted 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 spatial path attenuation as , according to the calculation formula Get the original signal of each channel per unit time after demodulation ,in It is represented by the attenuation coefficient of the signal transmitted from the user terminal to the satellite during space propagation set in the database. 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 value of the transmission frequency, bandwidth and spatial path attenuation of the signal 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 assessment coefficient of each channel per unit time is compared with the signal strength assessment coefficient threshold in the database. When the signal strength assessment coefficient of a channel per unit time is less than the signal strength assessment 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 encrypted signals. Otherwise, it is judged that the signal transmitted by the channel per unit time is complete, and the channel is used to transmit encrypted signals.

6. A satellite communication method according to claim 5, characterized in that: 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: Get signal strength endpoint coordinates And calculate the slope , Indicates The end time of the unit time of the channel, Indicates 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 ; The strength evaluation coefficient of the signal at the end moment of the next unit time is compared 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 specific process of establishing a communication connection between the satellite and the target ground station is as follows: 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 function after demodulation ,in It is expressed as the attenuation coefficient of the signal transmitted from the satellite to the target ground station set in the database during space propagation. is the correction factor of the satellite communication signal in the database.

9. A device for satellite communication, applying a method for satellite communication 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, used to execute a satellite communication method as claimed in claims 1 to 8, characterized in that: include: 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; 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 evaluation 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, and analyze whether to change the transmission channel based on the prediction results; Satellite transmission signal: establish a communication connection between the satellite and the target ground station, and transmit 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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