CN112332918B - Space laser communication system - Google Patents
Space laser communication system Download PDFInfo
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- CN112332918B CN112332918B CN202011199639.9A CN202011199639A CN112332918B CN 112332918 B CN112332918 B CN 112332918B CN 202011199639 A CN202011199639 A CN 202011199639A CN 112332918 B CN112332918 B CN 112332918B
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/11—Arrangements specific to free-space transmission, i.e. transmission through air or vacuum
- H04B10/118—Arrangements specific to free-space transmission, i.e. transmission through air or vacuum specially adapted for satellite communication
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/50—Transmitters
- H04B10/501—Structural aspects
- H04B10/503—Laser transmitters
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/50—Transmitters
- H04B10/516—Details of coding or modulation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/14—Relay systems
- H04B7/15—Active relay systems
- H04B7/185—Space-based or airborne stations; Stations for satellite systems
- H04B7/18521—Systems of inter linked satellites, i.e. inter satellite service
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/14—Relay systems
- H04B7/15—Active relay systems
- H04B7/185—Space-based or airborne stations; Stations for satellite systems
- H04B7/18523—Satellite systems for providing broadcast service to terrestrial stations, i.e. broadcast satellite service
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/14—Relay systems
- H04B7/15—Active relay systems
- H04B7/185—Space-based or airborne stations; Stations for satellite systems
- H04B7/1853—Satellite systems for providing telephony service to a mobile station, i.e. mobile satellite service
- H04B7/18565—Arrangements for preventing unauthorised access or for providing user protection
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/14—Relay systems
- H04B7/15—Active relay systems
- H04B7/185—Space-based or airborne stations; Stations for satellite systems
- H04B7/18578—Satellite systems for providing broadband data service to individual earth stations
- H04B7/18593—Arrangements for preventing unauthorised access or for providing user protection
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
- H04L9/08—Key distribution or management, e.g. generation, sharing or updating, of cryptographic keys or passwords
- H04L9/0816—Key establishment, i.e. cryptographic processes or cryptographic protocols whereby a shared secret becomes available to two or more parties, for subsequent use
- H04L9/0819—Key transport or distribution, i.e. key establishment techniques where one party creates or otherwise obtains a secret value, and securely transfers it to the other(s)
- H04L9/0825—Key transport or distribution, i.e. key establishment techniques where one party creates or otherwise obtains a secret value, and securely transfers it to the other(s) using asymmetric-key encryption or public key infrastructure [PKI], e.g. key signature or public key certificates
Abstract
The invention relates to a space laser communication system, which comprises a receiving end and a plurality of low-orbit satellites, wherein at least one satellite in the plurality of low-orbit satellites can transmit modulated optical signals to the earth in a mode of generating light spots of laser beams on the earth so as to broadcast to the receiving end within the coverage range of the laser beams. The invention adopts laser beams to transmit modulated optical signals to a target area so as to carry out laser broadcasting to a plurality of receiving ends in the target area, a large number of satellite-to-ground laser communication terminals do not need to be installed on a satellite, and one-to-many laser broadcasting is efficiently realized.
Description
The invention relates to a low-speed communication method and system based on light flicker of a low-orbit satellite, which have the application number of 201910077310.6, the application date of 2019, the date of 01, the date of 25 and the application type of the invention.
Technical Field
The invention relates to the field of communication, in particular to a space laser communication system.
Background
The space laser communication is optical communication taking laser as a carrier wave and air as a transmission medium, and the laser has the characteristics of good directivity, high brightness, good monochromaticity and the like, and is very suitable to be used as a carrier of short-distance optical communication. Compared with microwave communication, the wireless laser communication has the characteristics of no need of applying a communication frequency band, large information capacity, wide frequency band, strong anti-electromagnetic interference capability, good confidentiality and the like. Compared with optical fiber communication and other wired communication, the method has the characteristics of flexibility, low operation cost, easiness in popularization and the like.
The technical scheme mainly adopted by the space laser communication system is that a small-field-of-view optical antenna and a high-precision tracking and aiming device are adopted, the optical axis of the optical antenna of the communication terminal is aligned by the high-precision tracking and aiming device, the system can work, and although the transmission speed is high, the point-to-point laser communication cannot simultaneously carry out laser communication on a plurality of targets. Therefore, in the prior art, a single satellite carries a plurality of laser communication terminals so as to be capable of laser communication with a plurality of targets. For example, chinese patent publication No. CN108462526A discloses a laser communication satellite, which relates to the technical field of laser communication and mainly aims to provide services for a plurality of laser communication terminals by one satellite at the same time at a lower cost. The laser communication satellite comprises at least one satellite-borne system, wherein the satellite-borne system comprises a laser communication terminal and an electric cabinet; the electric cabinet is used for supplying power to the laser communication terminal and providing a control instruction and an information flow; the laser communication terminal comprises at least two inter-satellite laser communication terminals and a plurality of satellite-ground laser communication terminals; the at least two inter-satellite laser communication terminals are used for carrying out laser two-way communication with other satellites; the plurality of satellite-ground laser communication terminals are used for carrying out bidirectional laser communication with a corresponding number of ground stations and aircrafts at the same time; each satellite-ground laser communication terminal can scan the field angle to the ground of the satellite where the satellite is located. However, this solution still has a limitation because the satellite can carry a limited load, and the number of satellite-to-ground laser communication terminals carried is limited so that the number of receiving terminals capable of simultaneously receiving data is limited. Therefore, there is a need for improvements in the prior art.
The patent document with publication number CN108390715A in the prior art discloses a terminal layout structure of a laser communication satellite, which is only suitable for adding a plurality of laser communication terminals on the existing satellite, so as to realize that one satellite provides services for a plurality of laser communication terminals at the same time at a lower cost, and does not relate to a technical scheme that communication transmission can be realized between a single satellite and a plurality of receiving terminals without adopting a laser communication terminal, and there is no content for improving laser signals transmitted by the satellite; and a laser broadcast communication method disclosed in patent document CN103607241B of the related art, which is suitable for signal transmission by combining laser communication with television broadcasting, but does not involve transmission of signals to satellites. The above prior art does not disclose the technical feature of the present invention that at least one of the low earth orbit satellites can emit a modulated optical signal toward the earth in a manner that can generate a light spot of a laser beam on the earth to broadcast to a receiving end within the coverage of the laser beam, and the present application solves the technical problems that the satellite loadable load is limited, the number of loaded satellite-to-ground laser communication terminals is limited, and the number of receiving ends capable of receiving data simultaneously is limited, which are faced by the above prior art.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a low-speed communication method and a system based on light flicker of a low-orbit satellite.
According to a preferred embodiment, a low-speed communication system based on light flashing of low-earth orbit satellites, in particular a laser broadcast communication system, comprises a receiving end and a plurality of low-earth orbit satellites, and the system transmits modulated light signals to a target area through at least one of the plurality of low-earth orbit satellites so as to perform laser broadcasting to the receiving end in the target area.
According to a preferred embodiment, at least one of the low earth orbit satellites amplitude modulates the green laser light, the blue laser light or the blue-green laser light to obtain the modulated light signal.
According to a preferred embodiment, each of the low earth orbit satellites comprises a laser, an electro-optic modulator, a signal source and a transmitting antenna, the laser and the signal source are respectively connected to the electro-optic modulator, the electro-optic modulator is connected to the transmitting antenna, the electro-optic modulator modulates laser emitted by the laser by using a signal emitted by the signal source, and the transmitting antenna transmits the modulated laser to a target area after the modulated laser is expanded.
According to a preferred embodiment, the low-orbit satellites include at least twenty-seven satellites, the at least twenty-seven satellites are distributed on three orbital planes arranged at an included angle with each other, and at least nine satellites are respectively arranged on a first orbital plane, a second orbital plane and a third orbital plane of the three orbital planes, and the system can transmit data to corresponding receiving terminals through the low-orbit satellites in a clear text mode, wherein when the low-speed communication system transmits data through at least part of the low-orbit satellites in the clear text mode, transmitting antennas of at least part of the low-orbit satellites can transmit the same unencrypted optical signals independently carrying the data to respective target areas so as to perform laser broadcasting to the receiving terminals in the respective target areas.
According to a preferred embodiment, the system is further capable of sending data to corresponding receiving terminals in a ciphertext mode through at least some of the plurality of low earth orbit satellites, when the system sends data in the ciphertext mode through the plurality of low earth orbit satellites, the transmitting antennas of at least two of the plurality of low earth orbit satellites transmit mutually different optical signals, which commonly carry data, to the same target area, so as to perform laser broadcasting to all receiving terminals of the target area, and after receiving the mutually different optical signals, which commonly carry data, transmitted by the transmitting antennas of the at least two satellites, the receiving terminals decrypt the mutually different optical signals to obtain the data.
According to a preferred embodiment, the ciphertext mode includes a first ciphertext mode, in the first ciphertext mode, the data is divided into two parts and separately transmitted by two satellites on the same orbital plane in the three orbital planes in a manner of transmitting optical signals different from each other to the target area by laser beams forming an included angle, in the first ciphertext mode, the included angle of the laser beams transmitted by the two satellites on the same orbital plane continuously changes along with the operation of the two satellites on the same orbital plane, and after receiving the optical signals different from each other transmitted by the two satellites on the same orbital plane, the corresponding receiving end decrypts the optical signals by a first preset decryption manner corresponding to the first ciphertext mode to obtain the data.
According to a preferred embodiment, the ciphertext modes include a second ciphertext mode, in the second ciphertext mode, the data are divided into two parts and separately transmitted by two satellites on two different orbital planes of the three orbital planes in a manner of transmitting optical signals different from each other to the target area by laser beams forming an included angle, in the second ciphertext mode, the included angle of the laser beams transmitted by the two satellites on the two different orbital planes continuously changes along with the operation of the two satellites on the different orbital planes, and after the corresponding receiving end receives the optical signals different from each other transmitted by the two satellites on the two different orbital planes, the data are decrypted by a second preset decryption manner corresponding to the second ciphertext mode to obtain the data.
According to a preferred embodiment, the ciphertext modes include a third ciphertext mode, in the third ciphertext mode, the data are divided into three parts and separately transmitted by three satellites on the first orbit surface, the second orbit surface and the third orbit surface in a manner that laser beams forming included angles transmit optical signals different from each other to the target area, in the third ciphertext mode, the included angles of the laser beams transmitted by the three satellites on the first orbit surface, the second orbit surface and the third orbit surface respectively change along with the operation of the three satellites on different orbit surfaces, and after receiving the optical signals different from each other transmitted by the three satellites, the corresponding receiving end decrypts the data by a third preset decryption method corresponding to the third ciphertext mode to obtain the data.
According to a preferred embodiment, in a ciphertext mode, data is divided into a plurality of data segments by one satellite, a part of the data segments are transmitted to the satellite which is to transmit the data together by the satellite which divides the data through an inter-satellite link, and the satellite which divides the data encrypts the data and then divides the encrypted data into a plurality of data segments; in the first ciphertext mode, the satellite dividing the data encrypts the data by using a symmetric key and then divides the encrypted data into a plurality of data segments; in a second ciphertext mode, the satellite which divides data firstly encrypts the data by using a public key of an asymmetric encryption algorithm and then divides the encrypted data into a plurality of data segments; in the third ciphertext mode, the satellite dividing the data firstly encrypts the data once by using the symmetric key, then secondly encrypts the data by using the public key of the asymmetric encryption algorithm, and then divides the encrypted data into a plurality of data segments.
According to a preferred embodiment, a low-speed communication method based on light flicker of low-earth orbit satellites, in particular a laser broadcast communication method, comprises: the modulated optical signal is transmitted to a target area through at least one of a plurality of low earth orbit satellites to perform laser broadcasting to a receiving end within the target area.
Drawings
FIG. 1 is a schematic view of a first preferred embodiment of the present invention;
FIG. 2 is a schematic view of a second preferred embodiment of the present invention;
FIG. 3 is a schematic view of a third preferred embodiment of the present invention;
FIG. 4 is a schematic view of a fourth preferred embodiment of the present invention;
FIG. 5 is a schematic diagram of a preferred embodiment of the low earth orbit satellite of the present invention broadcasting laser to multiple receivers;
FIG. 6 is a schematic diagram of a preferred embodiment of the present invention for generating an optical signal; and
fig. 7 is a block diagram of a preferred embodiment of the present invention.
List of reference numerals
100: low earth satellite 110: the laser 120: electro-optic modulator
130: signal source 140: the transmitting antenna 150: control module
160: the optical module 200: receiving end
Detailed Description
The following detailed description is made with reference to fig. 1, 2, 3, 4, 5, 6 and 7.
In the description of the present invention, it is to be understood that, if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. are used for indicating the orientation or positional relationship indicated based on the drawings, they are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation and be operated, and thus, should not be construed as limiting the present invention.
In the description of the present invention, it is also to be understood that the terms "first," "second," and the like, if any, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, the term "plurality", if any, means two or more unless specifically limited otherwise.
In the description of the present invention, it should be further understood that the terms "mounting," "connecting," "fixing," and the like are used in a broad sense, and for example, the terms "mounting," "connecting," "fixing," and the like may be fixed, detachable, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. To one of ordinary skill in the art, the specific meaning of the above terms in the present invention can be understood as appropriate, unless explicitly stated and/or limited otherwise.
In the description of the present invention, it should also be understood that "over" or "under" a first feature may include the first and second features being in direct contact, and may also include the first and second features being in contact not directly but through another feature therebetween, unless expressly stated or limited otherwise. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.
Example 1
The embodiment discloses a low-speed communication method based on light flicker of low-orbit satellites, or a laser broadcast communication method, or a laser communication method, which can be realized by the system and/or other alternative parts. For example, the method of the present invention may be implemented using various components of the system of the present invention. The preferred embodiments of the present invention are described in whole and/or in part in the context of other embodiments, which can supplement the present embodiment, without resulting in conflict or inconsistency.
According to a preferred embodiment, the method may comprise: the modulated optical signal is transmitted to the target area through at least one of the plurality of low earth orbit satellites 100 to perform laser broadcasting to the receiving end 200 within the target area. For example, referring to fig. 1 and/or fig. 5, it is preferable that the receiving ends 200 in the target area can simultaneously receive the optical signals if they have communication conditions for receiving data.
According to a preferred embodiment, at least one of the plurality of low earth satellites 100 may amplitude modulate a red laser, a green laser, a blue laser, or a blue-green laser to obtain a modulated optical signal. It is particularly preferred that the invention uses green laser light as the carrier wave, which green laser light is amplitude modulated by the respective satellite to obtain the modulated light signal. The laser light emitted by the laser 110 may be green laser light having a wavelength ranging from 532nm to 556 nm. The invention can at least realize the following beneficial technical effects by adopting the mode: firstly, the information is broadcast by using amplitude-modulated laser, and compared with radio, the information is not easily interfered; secondly, during daytime communication, green laser can be better distinguished from a white background, so that data transmission is easier to identify; third, the use of green light enables a larger spot to be formed on the ground to better cover the target area.
According to a preferred embodiment, each of the number of low earth satellites 100 may include at least one of a laser 110, an electro-optic modulator 120, a signal source 130, and a transmitting antenna 140. The laser 110 and the signal source 130 may be separately connected to the electro-optic modulator 120. The electro-optic modulator 120 may be connected to a transmit antenna 140. The electro-optic modulator 120 may modulate the laser light emitted by the laser 110 with a signal emitted by the signal source 130. The transmitting antenna 140 may transmit the modulated optical signal toward a target area after the modulated laser light is expanded. See, for example, fig. 6.
According to a preferred embodiment, the number of low earth orbit satellites 100 may include at least twenty-seven satellites. At least twenty-seven satellites may be distributed on three orbital planes disposed at an angle to each other. At least nine satellites may be disposed on each of the first, second, and third orbital planes of the three orbital planes. Several low earth satellites 100 may transmit data in clear text mode to the corresponding receiving terminals 200. When at least some of the plurality of low earth satellites 100 transmit data in a clear text mode, the transmitting antennas 140 of at least some of the plurality of low earth satellites 100 may transmit the same unencrypted optical signals carrying data independently toward the respective target areas for laser broadcasting to the receiving ends 200 within the respective target areas. The invention can at least realize the following beneficial technical effects by adopting the mode: firstly, when the data is public data, the data is sent in a plaintext mode, and efficient laser broadcast communication can be achieved; second, in the plaintext mode, corresponding data can be transmitted through a single satellite, and the receiving end 200 can obtain the data more quickly.
Preferably, the orbit height of the low-orbit satellite can be 200-2000 kilometers, and particularly preferably 300-350 kilometers. Preferably, two adjacent track surfaces of the three track surfaces may have a track surface angle of 60 °.
According to a preferred embodiment, at least some of the plurality of low earth orbit satellites 100 may transmit data to the corresponding receiving end 200 in a cipher text mode. When at least some of the plurality of low earth satellites 100 transmit data in a ciphertext mode, the transmitting antennas 140 of at least two of the plurality of low earth satellites 100 may transmit different optical signals, which collectively carry data, toward the same target area, so as to perform laser broadcasting to all receiving terminals 200 in the target area. The receiving end 200 decrypts the received optical signals different from each other to obtain data after receiving the optical signals different from each other carrying data in common transmitted by the transmitting antennas 140 of at least two satellites. Preferably, as the satellite moves, the respective satellite can adjust the angle of its transmitting antenna and/or adjust the attitude by its powered components in order to direct the laser beam to the target area. Preferably, the transmission of the mutually different optical signals carrying data together by the transmitting antennas 140 of at least two satellites towards the same target area may be simultaneous transmission or non-simultaneous transmission. Preferably, the wavelength of the laser light emitted by the laser 110 can be adjusted. When transmitting simultaneously, the transmitting antennas 140 of at least two satellites transmitting data together transmit optical signals in a wavelength division multiplexing manner. So that the receiving end separates different optical signals transmitted by different satellites. Alternatively, the transmit antennas 140 of at least two satellites that collectively transmit data use carriers of different wavelengths. For example, one satellite may use laser light having a wavelength of 532nm, and another satellite may use laser light having a wavelength of 545nm or 556 nm. At the receiving end 200 the optical carriers of different wavelengths are separated via a demultiplexer. A demultiplexer may also be referred to as a demultiplexer or demultiplexer.
According to a preferred embodiment, the ciphertext mode may comprise a first ciphertext mode. In the first cipher text mode, data may be divided into two parts and separately transmitted by two satellites on the same orbital plane of the three orbital planes in such a manner that the laser beams at an angle emit optical signals different from each other to the target area, for example, see fig. 2. In the first ciphertext mode, the included angle of the laser beams emitted by the two satellites on the same orbital plane can be continuously changed along with the operation of the two satellites on the same orbital plane. After receiving the optical signals different from each other transmitted by two satellites on the same orbital plane, the corresponding receiving end 200 may decrypt the optical signals in a first preset decryption manner corresponding to the first ciphertext mode to obtain data. The invention can at least realize the following beneficial technical effects by adopting the mode: firstly, two satellites on the same orbit surface are adopted to respectively send two parts of data by laser beams forming an included angle, even if an eavesdropper wants to eavesdrop, the eavesdropper also needs to enter the coverage area of the laser beams, and because of the uncertainty of the satellites for emitting the laser beams, the emitting angle and the position of the laser beams are not fixed, so that the difficulty for simultaneously obtaining optical signals of the two satellites is quite high, if the eavesdropper uses a ground eavesdropping device, the eavesdropping can hardly be carried out at any time, even if the aerial eavesdropping device is used, the aerial eavesdropping device is not found by a user of a receiving end 200, the aerial eavesdropping device needs to eavesdrop at the height as high as possible, and meanwhile, two paths of data are high, the difficulty is quite high, and therefore, the difficulty for eavesdropping the data is increased by a first ciphertext mode of the invention; secondly, data are transmitted by laser, so that the data are not easily interfered by the outside; third, the present invention may be used to send a strategy to a strategy team at the time of a strategy.
According to a preferred embodiment, the ciphertext mode may comprise a second ciphertext mode. In the second cipher text mode, data may be divided into two parts and separately transmitted by two satellites in two different orbital planes of the three orbital planes in such a way that the laser beams at an angle emit optical signals different from each other to the target area, for example, see fig. 3. In the second ciphertext mode, the included angle of the laser beams emitted by the two satellites on the two different orbital planes can be continuously changed along with the operation of the two satellites on the different orbital planes. After receiving the optical signals different from each other sent by two satellites on two different orbital planes, the corresponding receiving end 200 may decrypt the optical signals to obtain data in a second preset decryption manner corresponding to the second ciphertext mode. The invention can at least realize the following beneficial technical effects by adopting the mode: two satellites in two different orbits are used for respectively transmitting two parts of data, so that the data transmitted in the second cryptograph mode is less prone to eavesdropping compared with the data transmitted in the first cryptograph mode.
According to a preferred embodiment, the ciphertext modes may include a third ciphertext mode. In the third cipher text mode, data may be divided into three parts and separately transmitted by three satellites on the first, second, and third orbital planes in such a manner that the laser beams at the angles emit optical signals different from each other toward the target area, for example, see fig. 4. In the third ciphertext mode, included angles of laser beams emitted by three satellites on the first orbit surface, the second orbit surface and the third orbit surface respectively change continuously along with operation of the three satellites on different orbit surfaces, and after receiving optical signals which are different from each other and sent by the three satellites, the corresponding receiving end 200 decrypts the optical signals by a third preset decryption mode corresponding to the third ciphertext mode to obtain data. The invention can at least realize the following beneficial technical effects by adopting the mode: three satellites in three different orbits are used to transmit three parts of data respectively, so that the data transmitted in the third cryptograph mode is less prone to eavesdropping than the data transmitted in the second cryptograph mode.
Preferably, the first ciphertext mode may encrypt the data in a first preset encryption manner. The second ciphertext mode may encrypt the data using a second predetermined encryption manner. The third ciphertext mode may encrypt the data using a third predetermined encryption manner. Preferably, the first, second and third preset encryption manners may be different from each other. Preferably, the difficulty of decryption of the first, second and third preset decryption modes increases in sequence.
According to a preferred embodiment, in the ciphertext mode, the data may be partitioned into data segments by at least one satellite. The satellite that segments the data may transmit some of the data segments to the satellite that is to transmit the data together via an inter-satellite link. The satellite that segments the data may encrypt the data before segmenting the encrypted data into data segments. In the first ciphertext mode, the satellite that segments the data may encrypt the data using the symmetric key before segmenting the encrypted data into data segments. In the second ciphertext mode, the satellite that segments the data may encrypt the data using the public key of the asymmetric encryption algorithm before segmenting the encrypted data into a plurality of data segments. In the third ciphertext mode, the satellite that segments the data may encrypt the data once using the symmetric key, then encrypt the data twice using the public key of the asymmetric encryption algorithm, and then segment the encrypted data into a plurality of data segments.
According to a preferred embodiment, for the same data, the granularity at which the data is partitioned is smaller in the first, second and third ciphertext modes. Therefore, the cracking difficulty is gradually increased. Preferably, the satellite stores different segmentation algorithms corresponding to the first, second and third ciphertext modes. Preferably, the receiving end 200 stores a corresponding merging algorithm corresponding to different segmentation algorithms of the first, second and third ciphertext modes. Preferably, the data division transmission itself can also be counted as one-time encryption, so that the cracking difficulty is increased. Preferably, after the receiving end 200 receives the corresponding optical signal, the receiving end 200 may convert the optical signal into an electrical signal. The receiving end 200 may decrypt the encrypted data using a corresponding preset decryption algorithm to obtain the data. The receiving end 200 may be a mobile device. The receiving end 200 may have a photosensitive element. The receiving end 200 converts the optical signal into an electrical signal through the photosensitive element. Preferably, the receiving end 200 separates the received optical signals transmitted by two or three satellites and different from each other to obtain two or three separated electrical signals. The receiving end 200 may combine the electrical signals by using an adaptive combination algorithm according to the identified ciphertext mode to obtain encrypted data. Preferably, the receiving end 200 can directly decode or decrypt the electrical signal. Or the receiving end can transmit the electric signal to the mobile phone through the Bluetooth, and the mobile phone completes decoding or decryption.
According to a preferred embodiment, the ciphertext mode of the present invention may not be limited to only the above encryption schemes. For example, the ciphertext mode may be encrypted once, twice or three times by using a morse code or Hash encryption algorithm.
Example 2
This embodiment may be a further improvement and/or a supplement to embodiment 1, and repeated contents are not described again. The preferred embodiments of the present invention are described in whole and/or in part in the context of other embodiments, which can supplement the present embodiment, without resulting in conflict or inconsistency.
The embodiment also discloses a low-speed communication system based on the light flicker of the low-orbit satellite, or a laser broadcast communication system, or a laser communication system, which is suitable for executing the steps of the method disclosed by the invention to achieve the expected technical effect.
According to a preferred embodiment, the system may include a receiving end 200 and a number of low earth orbit satellites 100. The system may transmit a modulated optical signal to a target area through at least one of a number of low earth orbit satellites 100 to perform laser broadcasting to a receiving end 200 within the target area.
According to a preferred embodiment, at least one of the plurality of low earth orbit satellites 100 can transmit a modulated optical signal towards the earth in such a way as to generate a spot of a laser beam on the earth, for broadcasting towards a receiving end 200 within the coverage of the laser beam.
According to a preferred embodiment, the transmitting antenna 140 can transmit the modulated laser light toward the target area after being expanded to form a spot coverage area in the target area that covers at least a portion of the target area. The transmitting antenna 140 may perform laser broadcasting to all receiving terminals 200 within the coverage area of the spot by optical signals. Preferably, the fact that the transmitting antenna 140 can broadcast the laser to all receiving terminals 200 within the coverage area of the spot does not mean that all receiving terminals 200 within the coverage area of the spot can receive the information, because some of the receiving terminals 200 within the coverage area of the spot may be in a state where they are not visible to each other from the satellite. In the case where one receiving end 200 or more than one receiving end 200 exists within the target area, the optical signal transmitted by the transmitting antenna 140 can be received as long as the corresponding receiving end 200 and the transmitting antenna 140 are visible to each other. The invention can at least realize the following beneficial technical effects by adopting the mode: firstly, in the prior art, point-to-point laser communication is established between a satellite and a ground station, although the mode has a fast communication rate, the one-to-many service cannot be provided after all, and the invention broadcasts to all receiving terminals 200 in a target area through optical signals, thereby realizing the data transmission to multiple points through laser; secondly, when the existing satellite sends information to a plurality of receiving terminals 200 on the ground through microwaves, the problem of radio spectrum control needs to be considered, and the method can avoid the radio spectrum control and quickly send information to the plurality of receiving terminals 200 in a target area; thirdly, the invention does not need to make the receiving end 200 on the ground accurately establish a one-to-one communication link through the ATP device, which saves the time for establishing the link and has the efficiency advantage that the prior art can not compare when the satellite transmits a small amount of data to a plurality of receiving ends 200.
According to a preferred embodiment, the diameter of the spot is between 1km and 11 km. Particularly preferably, the diameter of the light spot is 8km to 10 km.
According to a preferred embodiment, the system can transmit data to the corresponding receiving end 200 in a plaintext mode and/or a ciphertext mode through a plurality of low earth orbit satellites 100.
Preferably, when the low-speed communication system transmits data in a clear text mode through the plurality of low-orbit satellites 100, the transmitting antennas 140 of at least some of the plurality of low-orbit satellites 100 may transmit the same optical signal carrying the data toward the respective target areas to form a spot coverage area covering at least a portion of the target areas in the respective target areas for laser broadcasting to all receiving terminals 200 within the corresponding spot coverage areas. Preferably, the spot footprints of the two low earth satellites 100 may not overlap or partially overlap each other.
According to a preferred embodiment, when the system transmits data in a cipher text mode through a plurality of low earth satellites 100, the transmitting antennas 140 of at least two of the plurality of low earth satellites 100 may transmit mutually different optical signals carrying data in common toward the same target area to form at least two spot coverage areas covering at least a portion of the target area in the target area for laser broadcasting to all receiving terminals 200 within the spot coverage area. Preferably, the spot footprints of the two low earth satellites 100 may not overlap or partially overlap each other.
According to a preferred embodiment, in the first ciphertext mode and the second ciphertext mode, the satellites that segment the data may select the satellites that are to transmit the data together based on weather conditions and visibility conditions, and the satellites that segment the data preferentially select two satellites that are currently furthest apart to transmit the data together if the weather conditions and visibility conditions allow. The invention can at least realize the following beneficial technical effects by adopting the mode: the method can further increase the difficulty of successfully eavesdropping the data.
According to a preferred embodiment, in the third cipher text mode, the satellites that segment the data select the satellites that are to transmit the data together based on the weather condition and the visibility condition, and the satellites that segment the data preferentially select three satellites that are farthest from the sum of the current straight-line distances to transmit the data together if the weather condition and the visibility condition allow. The invention can at least realize the following beneficial technical effects by adopting the mode: the method can further increase the difficulty of successfully eavesdropping the data.
According to a preferred embodiment, when the low-speed communication system needs to transmit data in the first ciphertext mode through the plurality of low-earth satellites 100, the low-speed communication system firstly broadcasts the hash value of the data to the receiving end 200 within the coverage of the laser beam through at least one satellite of the plurality of low-earth satellites 100 in a laser broadcasting manner.
According to a preferred embodiment, before the low-speed communication system transmits data in a cipher text mode through the low-orbit satellites 100, the satellites dividing the data randomly select at least one satellite from all the satellites capable of performing laser broadcasting to the target area among the low-orbit satellites 100 based on communication conditions and perform laser broadcasting on the hash value of the data to the receiving end 200 of the target area. Preferably, the satellite that transmitted the hash value of the data is different from the satellite that transmitted the data. Therefore, the difficulty of the eavesdropper in obtaining the hash value of the data is increased, and if the eavesdropper does not obtain the hash value of the data, whether the data is complete or accurate is difficult to confirm, so that the difficulty of eavesdropping the data is further improved.
Preferably, the transmission rate of the data during the laser broadcasting is 10-300 Kbit/s, and particularly preferably, the transmission rate is 10-50 Kbit/s.
According to a preferred embodiment, each of the number of low earth orbit satellites may include an optics module 160 and a control module 150. The control module 150 may be coupled to at least one of the optical module 160, the electro-optic modulator 120, the signal source 130, and the laser 110, respectively. The control module 150 may control at least one of the optical module 160, the electro-optic modulator 120, the signal source 130, and the laser 110. The optical module may be arranged to sense ambient light directed in the opposite direction to the transmitting antenna 140. The optical module may be arranged to sense ambient light of the atmospheric space between the transmitting antenna 140 and the target area. The control module may dynamically adjust the amplitude of a 1 in the optical signal transmitted by the transmit antenna 140 by controlling the laser 110 and the electro-optic modulator 120 according to the intensity of the ambient light sensed by the optical module. Preferably, the optical module and the transmitting antenna 140 are independently attached to the frame of the satellite and independently move, respectively, and the control module recognizes the pointing direction of the transmitting antenna 140 and adjusts the orientation of the optical module according to the pointing direction of the transmitting antenna 140 so that the optical module is disposed to sense the ambient light in the direction opposite to the pointing direction of the transmitting antenna 140. The invention can at least realize the following beneficial technical effects by adopting the mode: the optical module senses the intensity of the ambient light to dynamically adjust the amplitude of the optical signal so as to increase the amplitude of the optical signal representation 1 when the light is enhanced or reduce the amplitude of the optical signal representation 1 when the light is weakened, so that the reliability can be ensured when the ambient light is enhanced, and the energy consumption can be reduced when the ambient light is weakened.
The word "module" as used herein describes any type of hardware, software, or combination of hardware and software that is capable of performing the functions associated with the "module".
It should be noted that the above-mentioned embodiments are exemplary, and that those skilled in the art, having benefit of the present disclosure, may devise various arrangements that are within the scope of the present disclosure and that fall within the scope of the invention. It should be understood by those skilled in the art that the present specification and figures are illustrative only and are not limiting upon the claims. The scope of the invention is defined by the claims and their equivalents.
Claims (10)
1. A spatial laser communication system comprising a receiving terminal (200) and a plurality of low earth orbit satellites (100), at least one of the plurality of low earth orbit satellites (100) transmitting a modulated optical signal towards the earth in such a way as to generate a spot of a laser beam on the earth for broadcasting to the receiving terminal (200) within the coverage of the laser beam;
each of the low earth orbit satellites (100) comprises a laser (110), an electro-optic modulator (120), a signal source (130) and a transmitting antenna (140), the laser (110) and the signal source (130) are respectively connected to the electro-optic modulator (120), the electro-optic modulator (120) is connected to the transmitting antenna (140), the electro-optic modulator (120) modulates the laser emitted by the laser (110) by using a signal emitted by the signal source (130), and the transmitting antenna (140) transmits a modulated optical signal to a target area after the modulated laser is expanded;
when the system transmits data in a clear text mode via a plurality of low earth satellites (100), the transmitting antennas (140) of at least some of the plurality of low earth satellites (100) transmit the same optical signals carrying data independently towards respective target areas to form a spot coverage area covering at least a portion of the target area in the respective target areas for laser broadcasting to all receivers (200) within the corresponding spot coverage area;
when the system transmits data in a ciphertext mode through a plurality of low orbit satellites (100), transmitting antennas (140) of at least two satellites in the plurality of low orbit satellites (100) transmit different optical signals carrying data together towards the same target area to form at least two spot coverage areas at least covering a part of the target area in the target area, so as to perform laser broadcasting to all receiving ends (200) of the target area in the spot coverage areas.
2. The system of claim 1, wherein the transmitting antenna (140) is configured to transmit the modulated laser light after being broadened toward the target area to form a spot coverage area in the target area that covers at least a portion of the target area, and wherein the transmitting antenna (140) is configured to broadcast the laser light via the optical signal to all receiving ends (200) in the spot coverage area.
3. The system of claim 2, wherein the plurality of low earth satellites (100) transmit data in clear text mode to respective receivers (200), and wherein the transmit antennas (140) of at least some of the plurality of low earth satellites (100) transmit the same unencrypted optical signals carrying data independently toward respective target areas for laser broadcast to the receivers (200) within the respective target areas when at least some of the plurality of low earth satellites (100) transmit data in clear text mode.
4. The system of claim 2, wherein at least some of the plurality of low earth satellites (100) transmit data to the corresponding receiving terminals (200) in a cipher text mode, and when at least some of the plurality of low earth satellites (100) transmit data in the cipher text mode, the transmitting antennas (140) of at least two of the plurality of low earth satellites (100) transmit mutually different optical signals, which collectively carry the data, toward the same target area to perform laser broadcasting to all receiving terminals (200) of the target area.
5. A system as claimed in claim 2, characterized in that, when the system transmits data in clear text mode via a plurality of low earth satellites (100), the transmitting antennas (140) of at least some of the plurality of low earth satellites (100) transmit the same optical signals carrying the data towards the respective target areas to form a spot coverage area covering at least a part of the target area in the respective target areas for laser broadcasting to all receiving terminals (200) within the corresponding spot coverage area.
6. The system of claim 5, wherein when the system transmits data in cipher text mode via the plurality of low earth satellites (100), the transmitting antennas (140) of at least two of the plurality of low earth satellites (100) transmit mutually different optical signals carrying data in common towards the same target area to form at least two spot coverage areas at the target area covering at least a portion of the target area for laser broadcasting to all receivers (200) within the spot coverage area.
7. A system according to claim 5 or 6, wherein the spot footprints of two low earth satellites (100) do not overlap or partially overlap each other.
8. A system as claimed in claim 7, wherein, as the satellites move, the respective satellites adjust the angle of their transmitting antennas and/or the attitude by its powered components in order to direct the laser beam at the target area.
9. The system of claim 8, wherein the transmitting antennas (140) of at least two satellites transmit different optical signals carrying data in common towards the same target area, simultaneously or non-simultaneously.
10. The system of claim 9, wherein the transmitting antennas (140) of the at least two satellites that collectively transmit data transmit optical signals using wavelength division multiplexing during simultaneous transmission.
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| CN201910077310.6A CN109921856B (en) | 2019-01-25 | 2019-01-25 | Low-speed communication method and system based on light flicker of low-orbit satellite |
| CN202011199639.9A CN112332918B (en) | 2019-01-25 | 2019-01-25 | Space laser communication system |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102318245A (en) * | 2008-12-10 | 2012-01-11 | 阿斯特里姆有限公司 | Content broadcasting |
| US9391702B2 (en) * | 2013-05-15 | 2016-07-12 | Worldvu Satellites Limited | System and method for multiple layer satellite communication |
| US9843388B1 (en) * | 2015-06-08 | 2017-12-12 | Amazon Technologies, Inc. | Laser communications |
| CN107528637A (en) * | 2017-05-19 | 2017-12-29 | 哈尔滨工业大学 | Ultrahigh speed data transmission laser system in a kind of star |
| CN107707297A (en) * | 2017-11-03 | 2018-02-16 | 潘运滨 | A kind of airborne laser communication system and its communication means |
Family Cites Families (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BR9912826A (en) * | 1998-07-16 | 2001-05-02 | Terabeam Networks Inc | Optical communication system that transmits and receives data through free space |
| CN102609640B (en) * | 2004-10-25 | 2015-07-15 | 安全第一公司 | Secure data parser method and system |
| CN100454790C (en) * | 2006-04-28 | 2009-01-21 | 哈尔滨工业大学 | All optical satellite communication network route terminal |
| US20090162071A1 (en) * | 2007-12-19 | 2009-06-25 | Refai Hakki H | Auto-Tracking System for Mobile Free-Space Optical (FSO) Communications |
| US20130315604A1 (en) * | 2011-02-07 | 2013-11-28 | The Board Of Regents Of The University Of Oklahoma | Mobile bi-directional free-space optical network |
| CN102857294B (en) * | 2011-06-29 | 2014-12-31 | 重庆邮电大学 | Method and device for suppressing signal fading in laser communication from ground to GEO (geosynchronous) satellite |
| EP2615748B1 (en) * | 2011-12-20 | 2017-11-08 | Thales Alenia Space Schweiz AG | Optical downlink system |
| CN103607241B (en) * | 2013-11-14 | 2016-05-04 | 长春理工大学 | laser broadcast communication method |
| CN104038272B (en) * | 2014-06-10 | 2017-04-26 | 哈尔滨工业大学 | Medium earth orbit (MEO) global coverage constellation under limit of illumination |
| CN105741483B (en) * | 2014-12-09 | 2018-07-06 | 公安部第一研究所 | A kind of Security alert device for being used to supervise institute people's police |
| WO2016097832A1 (en) * | 2014-12-16 | 2016-06-23 | Kamil Idris | Communication between radio terminals on an extraterrestrial body using a space based component and an ancillary component located on the extraterrestrial body. |
| US10313010B2 (en) * | 2015-03-17 | 2019-06-04 | The Boeing Company | Laser communications in super-geosynchronous earth orbit |
| CN106533562B (en) * | 2016-11-30 | 2019-03-29 | 上海卫星工程研究所 | Space multi-user's multi-standard satellite laser communications system and method |
| US10270523B2 (en) * | 2017-06-21 | 2019-04-23 | Blue Digs LLC | Satellite terminal system with wireless link |
| CN107659397B (en) * | 2017-08-11 | 2020-09-25 | 深圳市钱海网络技术有限公司 | Sensitive information transmission method and system |
| CN207603641U (en) * | 2017-11-03 | 2018-07-10 | 潘运滨 | A kind of airborne laser communication system |
| CN108254760B (en) * | 2017-12-28 | 2020-02-18 | 中国科学技术大学 | Positioning and navigation method and system based on three quantum satellites |
| CN108390715A (en) * | 2018-04-20 | 2018-08-10 | 宁波光舟通信技术有限公司 | A kind of terminal layout structure of laser beam communications satellite |
| CN109039459A (en) * | 2018-06-15 | 2018-12-18 | 上海卫星工程研究所 | A method of improving anti-intercepting and capturing probability between satellite and Underwater Moving Target |
| CN109120343B (en) * | 2018-06-15 | 2020-05-29 | 上海卫星工程研究所 | Blue-green laser link building method suitable for satellite and underwater moving target |
-
2019
- 2019-01-25 CN CN201910077310.6A patent/CN109921856B/en active Active
- 2019-01-25 CN CN202011199640.1A patent/CN112332919B/en active Active
- 2019-01-25 CN CN202011199639.9A patent/CN112332918B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102318245A (en) * | 2008-12-10 | 2012-01-11 | 阿斯特里姆有限公司 | Content broadcasting |
| US9391702B2 (en) * | 2013-05-15 | 2016-07-12 | Worldvu Satellites Limited | System and method for multiple layer satellite communication |
| US9843388B1 (en) * | 2015-06-08 | 2017-12-12 | Amazon Technologies, Inc. | Laser communications |
| CN107528637A (en) * | 2017-05-19 | 2017-12-29 | 哈尔滨工业大学 | Ultrahigh speed data transmission laser system in a kind of star |
| CN107707297A (en) * | 2017-11-03 | 2018-02-16 | 潘运滨 | A kind of airborne laser communication system and its communication means |
Non-Patent Citations (2)
| Title |
|---|
| Novel use of photovoltaics for backup spacecraft laser communication system;Xinchen Guo等;《2017 IEEE Aerospace Conference》;20170608;第1-8页 * |
| 低轨道卫星自由空间光通信;潘运滨;《第十四届卫星通信学术年会论文集》;20180322;第436-441页 * |
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|---|---|
| CN112332919B (en) | 2022-02-11 |
| CN109921856B (en) | 2021-01-15 |
| CN112332919A (en) | 2021-02-05 |
| CN109921856A (en) | 2019-06-21 |
| CN112332918A (en) | 2021-02-05 |
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