CN117856876A - High-low orbit inter-satellite distributed cooperative communication system and method - Google Patents

High-low orbit inter-satellite distributed cooperative communication system and method Download PDF

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CN117856876A
CN117856876A CN202410254023.9A CN202410254023A CN117856876A CN 117856876 A CN117856876 A CN 117856876A CN 202410254023 A CN202410254023 A CN 202410254023A CN 117856876 A CN117856876 A CN 117856876A
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low
satellite
orbit satellite
cooperative
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CN117856876B (en
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李献斌
杨俊�
胡梅
郭熙业
瞿智
马超
杨志玺
刘苏洋
孟志军
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National University of Defense Technology
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
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    • Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks

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Abstract

The invention discloses a high-low orbit inter-satellite distributed cooperative communication system and a method, which relate to the field of satellite communication, wherein the system comprises: a high orbit satellite; the low-orbit communication unit is arranged on the high-orbit satellite and is used for sending a synchronizing signal, a cooperative relay time schedule and phase synchronization completion identification information to the high-orbit communication unit and receiving a data transmission request, a test signal and data to be transmitted sent to the high-orbit communication unit; the cooperative relay calculation unit is arranged on the high orbit satellite and is used for calculating a cooperative relay time schedule; a plurality of low-orbit satellites; the high-orbit communication unit is arranged on the low-orbit satellite and is used for sending a data transmission request, carrying out signal synchronization test, sending a test signal and sending data to be transmitted; and the inter-satellite interconnection unit is arranged on the low-orbit satellite and is used for carrying out data transmission between the low-orbit satellites. The invention can solve the problem of discontinuous transmission caused by the relative motion between the high-low orbit satellite and the low-orbit satellite with weak transmission capability, and improves the capacity and efficiency of satellite communication.

Description

High-low orbit inter-satellite distributed cooperative communication system and method
Technical Field
The invention relates to the technical field of satellite communication, in particular to a high-low orbit inter-satellite distributed cooperative communication system and method.
Background
With the progress of satellite remote sensing technology, the resolution of remote sensing has been improved to sub-meter level, both by optical and microwave imaging means. The improvement of the remote sensing resolution brings with the huge increase of the on-orbit observation data quantity, and the problem of efficient and convenient transmission of a large amount of on-orbit observation data becomes increasingly prominent. Meanwhile, for a low-orbit remote sensing satellite, because the orbit is lower, the coverage radius of the earth is smaller, and the data can be returned to the ground only in the period of time with ground feed link connection, so that the real-time use requirement of massive observation data is difficult to meet.
In order to solve the above problems, the chinese patent document with publication number CN113644957a, entitled "a satellite internet-oriented space-based information relay transmission method", proposes a space-based information relay transmission method, which uses a high-throughput high-orbit relay satellite as a remote data channel of a low-orbit observation satellite, and after the high-orbit satellite receives remote sensing data sent by a user satellite, the remote sensing data is sent to a ground station, so as to complete the data landing of the user satellite, and improve the timeliness of space-based information transmission. However, the method does not consider and solve the signal transmission problem caused by long transmission path and large signal attenuation between the high-orbit satellite and the low-orbit satellite, and simultaneously does not consider and solve the transmission discontinuity problem caused by the relative motion between the high-orbit satellite and the low-orbit satellite.
Disclosure of Invention
In order to solve part or all of the technical problems in the prior art, the invention provides a high-low orbit inter-satellite distributed cooperative communication system and a method.
The technical scheme of the invention is as follows:
in a first aspect, a high-low inter-rail distributed cooperative communication system is provided, including:
a high orbit satellite which runs on the high orbit;
the low-orbit communication unit is arranged on the high-orbit satellite and can be in communication connection with the high-orbit communication unit, and is used for sending synchronous signals, a cooperative relay time schedule comprising transmission time slots and the low-orbit satellite cooperative in each transmission time slot and phase synchronization completion identification information to the high-orbit communication unit, and receiving data transmission requests comprising the initiating time and the transmission data quantity, test signals and data to be transmitted sent by the high-orbit communication unit;
the cooperative relay calculation unit is arranged on the high-orbit satellite, connected with the pair of low-orbit communication units and used for calculating the cooperative relay time schedule according to the data transmission request;
a plurality of low-orbit satellites operating on low orbits;
the pair of high-orbit communication units are respectively arranged on the low-orbit satellites, and are used for sending a data transmission request to the pair of low-orbit communication units, receiving the synchronous signals and the cooperative relay time sequence table sent by the pair of low-orbit communication units, carrying out signal synchronization test according to the received synchronous signals and the cooperative relay time sequence table, sending test signals to the pair of low-orbit communication units, and sending data to be transmitted to the pair of low-orbit communication units;
and each low-orbit satellite is provided with an inter-satellite interconnection unit, the inter-satellite interconnection units are connected with the pair of high-orbit communication units, and the inter-satellite interconnection units are used for carrying out data transmission between the low-orbit satellites.
In a second aspect, a method for implementing the distributed cooperative communication between high and low orbit satellites by using the distributed cooperative communication system between high and low orbit satellites is further provided, including:
the low-orbit satellite determines a data transmission task, and transmits a data transmission request comprising an initiating time and a transmission data amount to the high-orbit satellite through a high-orbit communication unit;
the high-orbit satellite receives a data transmission request from the low-orbit communication unit and sends the data transmission request to the cooperative relay calculation unit, the cooperative relay calculation unit calculates and acquires a cooperative relay time sequence table comprising transmission time slots and cooperative low-orbit satellites in each transmission time slot according to the data transmission request and sends the cooperative relay time sequence table to the low-orbit communication unit, and the low-orbit communication unit broadcasts a synchronous signal and the cooperative relay time sequence table to each low-orbit satellite;
the low-orbit satellites for sending the data transmission requests determine other low-orbit satellites participating in cooperative relay communication and transmission data responsible for each low-orbit satellite participating in the cooperative relay communication according to the received cooperative relay time sequence table, and send the data to be transmitted to the other low-orbit satellites through an inter-satellite interconnection unit;
before transmitting data to be transmitted to the high-orbit satellite, all low-orbit satellites participating in cooperative relay communication perform signal synchronization test according to the received synchronization signals and a cooperative relay time sequence table;
all low-orbit satellites participating in cooperative relay communication transmit data to be transmitted to the high-orbit satellites in respective corresponding transmission time slots through the high-orbit communication units.
In some possible implementations, the calculating to obtain the cooperative relay time sequence table including the transmission time slots and the cooperative low-orbit satellites in each transmission time slot according to the data transmission request includes:
calculating the transmission time length according to the transmission data quantity and the data transmission rate between the low-orbit satellite and the high-orbit satellite;
dividing a transmission time slot according to the initiating time and the transmission time length;
determining cooperative low-orbit satellites in each transmission time slot according to the position information of the high-orbit satellites and the low-orbit satellites and the divided transmission time slots;
and generating a cooperative relay time sequence table according to the divided transmission time slots and the cooperative low-orbit satellites in each transmission time slot.
In some possible implementations, the transmission duration is calculated using the following formula:
wherein (1)>Indicates the transmission time length,/->Representing the amount of data transferred->Representing the average value of the data transmission rate between the low-orbit satellite and the high-orbit satellite.
In some possible implementations, the cooperative low-orbit satellites within each transmission time slot are determined according to the position information of the high-orbit satellites and the low-orbit satellites, and the divided transmission time slots in the following manner:
determining the positions of a high-orbit satellite and a low-orbit satellite at the initial time of each transmission time slot, and respectively calculating the pitch angle between the high-orbit satellite and each low-orbit satellite at the initial time of each transmission time slot;
comparing the obtained magnitude relation between each pitch angle and the half-wave beam width of the high-orbit satellite to the low-orbit communication unit, and reserving the pitch angle smaller than the half-wave beam width;
and taking the low-orbit satellite corresponding to the reserved pitch angle as the cooperative low-orbit satellite in the corresponding transmission time slot, and determining the cooperative low-orbit satellite in each transmission time slot.
In some possible implementations, the pitch angle between the high and low satellites is calculated using the following formula:
wherein,representation->Pitch angle between the lower high orbit satellite and the i-th low orbit satellite at the moment,representation->Three-dimensional coordinates of the high orbit satellite under the moment in a set coordinate system,representation->Three-dimensional coordinates of the ith low orbit satellite under the moment in a set coordinate system.
In some possible implementations, the signal synchronization test is performed in the following manner:
before each transmission time slot arrives, a synchronous signal sent by a low-orbit communication unit of the high-orbit satellite is tracked by a Cooks loop to a high-orbit communication unit of the low-orbit satellite in the corresponding transmission time slot, and corresponding frequency is obtained;
the cooperative low-orbit satellite in the corresponding transmission time slot calculates the Doppler frequency of the self and the high-orbit satellite according to the self speed and the high-orbit satellite speed;
the frequency obtained by tracking is Doppler corrected according to the Doppler frequency by the cooperative low orbit satellite in the corresponding transmission time slot, and a frequency correction value is obtained;
the Doppler frequency is superimposed on the obtained frequency correction value as the frequency reference value of the test signal by the cooperative low-orbit satellite in the corresponding transmission time slot, the phase jitter value obeying uniform distribution is generated and superimposed on the test signal, and the test signal is sent to the high-orbit satellite;
the high-orbit satellite receives the test signal, judges the signal-to-noise ratio of the test signal, and when the signal-to-noise ratio of the received test signal is larger than or equal to a preset signal-to-noise ratio threshold value, the signal synchronization test is finished, and the phase synchronization completion identification information is broadcasted to the cooperative low-orbit satellite in the corresponding transmission time slot.
In some possible implementations, the doppler frequency between the low-orbit satellite and the high-orbit satellite is calculated using the following formula:
wherein (1)>Indicating the Doppler frequency between the ith low-orbit satellite and the high-orbit satellite,/and the like>Indicates the frequency of the synchronization signal transmitted by the high orbit satellite, < >>Representing the three-dimensional speed of the high orbit satellite under the set coordinate system at the moment of calculation,representing the three-dimensional velocity of the ith low-orbit satellite in the set coordinate system at the moment of calculation,/->Representing three-dimensional coordinates of the high orbit satellite under the set coordinate system at the moment of calculation, and +.>Representing three-dimensional coordinates of the ith low orbit satellite in a set coordinate system at the moment of calculation,/->Indicating the speed of light.
In some possible implementations, the signal-to-noise ratio threshold is calculated using the following formula:
wherein (1)>Representing a signal-to-noise threshold, ">Representing the signal-to-noise ratio scaling factor of the signal,/->Indicating the number of co-operating low-orbit satellites in the same transmission time slot, < >>Representing the signal-to-noise ratio of a single low-orbit satellite transmission signal,/->Indicating the frequency of the ith low orbit satellite tracking.
In some possible implementations, the signal synchronization test is performed, and further including:
if the same low-orbit satellite exists in the current transmission time slot and the last transmission time slot for the signal synchronization test, the same low-orbit satellite sends the last acquired frequency correction value to the newly-appearing cooperative low-orbit satellite in the current transmission time slot, takes the frequency reference value acquired in the last signal synchronization test process as the frequency reference value of the test signal, superimposes the phase jitter value acquired in the last signal synchronization test process on the test signal, and sends the test signal to the high-orbit satellite;
calculating an average value of all received frequency correction values by the cooperative low-orbit satellite newly appearing in the current transmission time slot, superposing Doppler frequency of the cooperative low-orbit satellite and the Doppler frequency of the high-orbit satellite obtained by calculation on the average value as a frequency reference value of a test signal, generating a phase jitter value obeying uniform distribution, superposing the phase jitter value on the test signal, and transmitting the test signal to the high-orbit satellite;
the high-orbit satellite receives the test signal, judges the signal-to-noise ratio of the test signal, and when the signal-to-noise ratio of the received test signal is larger than or equal to a preset signal-to-noise ratio threshold value, the signal synchronization test is finished, and the phase synchronization completion identification information is broadcasted to the cooperative low-orbit satellite in the current transmission time slot.
The technical scheme of the invention has the main advantages that:
according to the high-low orbit inter-satellite distributed cooperative communication system and method, the data of the low orbit satellites are transmitted to the high orbit satellites by utilizing the cooperative relay of the plurality of low orbit satellites, so that the problem that a single low orbit satellite is limited by weak transmission capacity caused by the size and power consumption of a platform can be effectively solved, the problem of discontinuous transmission caused by relative motion between the high orbit satellite and the low orbit satellite can be solved, and the capacity, the efficiency and the stability of high-low orbit satellite communication are remarkably improved.
Drawings
The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and without limitation to the invention. In the drawings:
FIG. 1 is a schematic diagram of a distributed cooperative communication system between high and low orbit satellites according to an embodiment of the invention;
fig. 2 is a flowchart of a distributed cooperative communication method between high and low orbit satellites according to an embodiment of the invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments of the present invention and corresponding drawings. It will be apparent that the described embodiments are only some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The following describes in detail the technical scheme provided by the embodiment of the invention with reference to the accompanying drawings.
Referring to fig. 1, in a first aspect, an embodiment of the present invention provides a high-low inter-rail distributed cooperative communication system, the system including:
a high orbit satellite 1 which runs on a high orbit;
a low-orbit communication unit 101, which is installed on the high-orbit satellite 1 and can be in communication connection with the high-orbit communication unit 201, and is used for sending synchronous signals, a cooperative relay time schedule comprising transmission time slots and the low-orbit satellite cooperative in each transmission time slot and phase synchronization completion identification information to the high-orbit communication unit 201, and receiving data transmission requests comprising initiation time and transmission data quantity, test signals and data to be transmitted sent to the high-orbit communication unit 201;
a cooperative relay calculation unit 102, installed on the high orbit satellite 1, connected to the low orbit communication unit 101, for calculating a cooperative relay timing table according to the data transmission request;
a plurality of low-orbit satellites 2 which are operated on a low orbit;
for the high-orbit communication units 201, each low-orbit satellite 2 is provided with a high-orbit communication unit 201, the high-orbit communication unit 201 is used for sending a data transmission request to the low-orbit communication unit 101, receiving a synchronous signal and a cooperative relay time sequence table sent to the low-orbit communication unit 101, carrying out signal synchronous test according to the received synchronous signal and the cooperative relay time sequence table, sending a test signal to the low-orbit communication unit 101, and sending data to be transmitted to the low-orbit communication unit 101;
and the inter-satellite interconnection units 202 are arranged on each low-orbit satellite 2, the inter-satellite interconnection units 202 are connected with the high-orbit communication units 201, and the inter-satellite interconnection units 202 are used for carrying out data transmission between the low-orbit satellites 2.
In practical application, the distributed cooperative communication system between high and low satellites provided by the embodiment of the invention can use a single low-orbit satellite to communicate with the high-orbit satellite independently, and can also use a plurality of low-orbit satellites to communicate with the high-orbit satellite in a cooperative relay communication mode.
Specifically, when a plurality of low-orbit satellites are used for communicating with a high-orbit satellite in a cooperative relay communication mode, the low-orbit satellite needing to perform data transmission firstly determines a data transmission task, determines the initiation time and the transmission data quantity of the data transmission according to the data transmission task, and sends a data transmission request comprising the initiation time and the transmission data quantity to the high-orbit satellite through a high-orbit communication unit; the high-orbit satellite receives a data transmission request from the low-orbit communication unit and sends the data transmission request to the cooperative relay calculation unit, the cooperative relay calculation unit calculates and acquires a cooperative relay time sequence table comprising transmission time slots and the cooperative low-orbit satellites in each transmission time slot according to the data transmission request and sends the cooperative relay time sequence table to the low-orbit communication unit, and the low-orbit communication unit broadcasts a synchronous signal and the cooperative relay time sequence table to each low-orbit satellite; each low-orbit satellite receives the synchronous signal and the cooperative relay time schedule through the high-orbit communication unit; the low-orbit satellites for sending the data transmission requests determine other low-orbit satellites participating in cooperative relay communication according to the received cooperative relay time sequence table, and determine transmission data which each low-orbit satellite participating in the cooperative relay communication needs to be responsible for transmission, and the transmission data to be transmitted is sent to the other low-orbit satellites through the inter-satellite interconnection units; before transmitting data to be transmitted to a high-orbit satellite, all low-orbit satellites participating in cooperative relay communication perform signal synchronization test according to the received synchronization signals and a cooperative relay time sequence table, so that data signals transmitted by the cooperative low-orbit satellites in each transmission time slot can reach the high-orbit satellite simultaneously; and after the signal synchronization test is finished and the corresponding transmission time slot arrives, the low-orbit satellite participating in cooperative relay communication sends data to be transmitted to the high-orbit satellite through the high-orbit communication unit.
Further, in an embodiment of the present invention, the high orbit represents a satellite orbit having a height of more than 20000 km, and the low orbit represents a satellite orbit having a height of less than 1000 km.
Specifically, in one embodiment of the present invention, the high orbit satellite is a geosynchronous satellite, and the orbit is 35786 km. The low orbit satellite uses Walker constellation satellites, 6 orbit planes are configured, 4 satellites are configured on each orbit plane, 24 satellites are configured on each orbit plane, the orbit height is 500 km, and the orbit inclination angle is 45 degrees.
Further, in an embodiment of the present invention, the specific device types for the low-rail communication unit and for the high-rail communication unit are specifically selected according to the actual situation, so long as the above-mentioned functions can be implemented. For example, a wide-beam microwave broadcasting device is used for low-rail communication units, and a narrow-beam microwave phased array device is used for high-rail communication units. The working frequency ranges of the low-rail communication unit and the high-rail communication unit are specifically set according to actual conditions. For example, when the high-orbit satellite and the low-orbit satellite employ the above-specifically defined satellite types, the operating band is set to the Ka band.
The specific equipment type of the cooperative relay calculation unit is specifically selected according to the actual situation, so long as the above functions can be realized. For example, the cooperative relay calculation unit adopts a radiation-resistant 32-bit microprocessor BM3803MGRH developed by the institute of Beijing microelectronics, aerospace, china.
The inter-satellite interconnection unit adopts laser communication equipment. Wherein, the operating wavelength of laser communication equipment is specifically set according to actual conditions. For example, when a low-orbit satellite employs the satellite type specifically defined above, the operating wavelength is set to 1550 nm.
Referring to fig. 2, in a second aspect, an embodiment of the present invention further provides a high-low inter-rail-satellite distributed cooperative communication method, where the method is implemented by using the above-mentioned high-low inter-rail-satellite distributed cooperative communication system, and includes the following steps S1 to S5:
in step S1, the low-orbit satellite determines a data transmission task by transmitting a data transmission request including an initiation time and a transmission data amount to the high-orbit satellite to the high-orbit communication unit.
Specifically, in an embodiment of the present invention, a low-orbit satellite determines whether data transmission is required according to a received instruction or according to a task condition executed by the low-orbit satellite, when the data transmission is required, the low-orbit satellite determines a data transmission task first, determines an initiation time and a transmission data amount of the data transmission according to the data transmission task, and then sends a data transmission request including the initiation time and the transmission data amount to the high-orbit satellite by sending the data transmission request to the high-orbit communication unit.
Step S2, the high-orbit satellite receives a data transmission request from the low-orbit communication unit and sends the data transmission request to the cooperative relay calculation unit, the cooperative relay calculation unit calculates and acquires a cooperative relay time sequence table comprising transmission time slots and the cooperative low-orbit satellites in each transmission time slot according to the data transmission request and sends the cooperative relay time sequence table to the low-orbit communication unit, and the low-orbit communication unit broadcasts the synchronous signals and the cooperative relay time sequence table to each low-orbit satellite.
In an embodiment of the present invention, a cooperative relay time schedule including transmission time slots and cooperative low-orbit satellites in each transmission time slot is obtained according to a data transmission request, and the method further includes the following steps:
step S21, calculating the transmission time length according to the transmission data quantity and the data transmission rate between the low-orbit satellite and the high-orbit satellite;
step S22, dividing transmission time slots according to the starting time and the transmission time length;
step S23, determining cooperative low-orbit satellites in each transmission time slot according to the position information of the high-orbit satellites and the low-orbit satellites and the divided transmission time slots;
step S24, generating a cooperative relay time sequence table according to the divided transmission time slots and the cooperative low-orbit satellites in each transmission time slot.
Specifically, in one embodiment of the present invention, the transmission duration is calculated using the following formula:
wherein (1)>Indicates the transmission time length,/->Representing the amount of data transferred->Representing the average value of the data transmission rate between the low-orbit satellite and the high-orbit satellite.
In an embodiment of the present invention, a time unit of the transmission time slot, for example, a unit of minutes is set before dividing the transmission time slot. Based on the time unit of the set transmission time slot, dividing the transmission time slot according to the starting time and the transmission time length.
Specifically, setting: the time unit of the transmission slot is 1 minute,expressed in minutesTransmission duration->Indicating the starting time; then divide into->The 1 st transmission time slot to the last transmission time slot are expressed as +.>、/>、/>、/>. Wherein (1)>Representing an upward rounding.
Further, in an embodiment of the present invention, according to the position information of the high-orbit satellite and the low-orbit satellite and the divided transmission time slots, the cooperative low-orbit satellite in each transmission time slot is determined in the following manner:
step S231, determining the positions of the high-orbit satellite and the low-orbit satellite at the initial time of each transmission time slot, and respectively calculating the pitch angle between the high-orbit satellite and each low-orbit satellite at the initial time of each transmission time slot;
step S232, comparing the obtained magnitude relation between each pitch angle and the half-wave beam width of the high-orbit satellite to the low-orbit communication unit, and reserving the pitch angle smaller than the half-wave beam width;
in step S233, the low-orbit satellite corresponding to the reserved pitch angle is used as the cooperative low-orbit satellite in the corresponding transmission time slot, and the cooperative low-orbit satellite in each transmission time slot is determined.
Specifically, to calculateTime lower high orbit satelliteFor example, the pitch angle between the i-th low-orbit satellite and the pitch angle between the high-orbit satellite and the low-orbit satellite is calculated by using the following formula:
wherein (1)>Representation->Pitch angle between time lower high orbit satellite and i low orbit satellite, +.>Representation ofThree-dimensional coordinates of high orbit satellite under time under set coordinate system, < >>Representation->Three-dimensional coordinates of the ith low orbit satellite at the moment in a set coordinate system, for example, a geocentric inertial coordinate system. The three-dimensional coordinates of the high-orbit satellite and the low-orbit satellite can be obtained through measurement and control data of ground surface injection, and can also be obtained through a satellite-borne navigation receiver.
In an embodiment of the present invention, the half-wave beam width of the high orbit satellite for the low orbit communication unit is determined according to practical situations, for example, 60 °.
And S3, determining other low-orbit satellites participating in cooperative relay communication and transmission data responsible for each low-orbit satellite participating in the cooperative relay communication according to the received cooperative relay time sequence table by the low-orbit satellite sending the data transmission request, and sending the data to be transmitted to the other low-orbit satellites through an inter-satellite interconnection unit.
Specifically, each low-orbit satellite receives a synchronous signal and a cooperative relay time sequence table from a high-orbit communication unit, and after receiving the cooperative relay time sequence table, the low-orbit satellite sending a data transmission request determines other low-orbit satellites participating in cooperative relay communication according to the received cooperative relay time sequence table, determines transmission data which each low-orbit satellite participating in cooperative relay communication needs to be responsible for transmission, and sends the data to be transmitted to the other low-orbit satellites through an inter-satellite interconnection unit.
And S4, performing signal synchronization test on all the low-orbit satellites participating in cooperative relay communication according to the received synchronization signals and the cooperative relay time sequence table before sending data to be transmitted to the high-orbit satellites.
In order to enable the data signals transmitted by the cooperative low-orbit satellites in each time slot to reach the high-orbit satellites substantially simultaneously, a signal synchronization test is required.
In one embodiment of the present invention, the following manner is used for signal synchronization testing:
step S41, before each transmission time slot arrives, a synchronous signal sent by a low-orbit communication unit of a high-orbit satellite is tracked by a Cositas loop on the high-orbit communication unit of a low-orbit satellite in the corresponding transmission time slot, and corresponding frequency is obtained;
step S42, calculating Doppler frequencies of the low-orbit satellite and the high-orbit satellite according to the speed of the low-orbit satellite and the speed of the high-orbit satellite, wherein the Doppler frequencies correspond to the low-orbit satellite in the transmission time slot;
step S43, the frequency obtained by tracking is Doppler corrected according to the Doppler frequency by the cooperative low orbit satellite in the corresponding transmission time slot, and a frequency correction value is obtained;
step S44, the Doppler frequency is superimposed on the acquired frequency correction value as the frequency reference value of the test signal by the cooperative low-orbit satellite in the corresponding transmission time slot, the phase jitter value obeying uniform distribution is generated and superimposed on the test signal, and the test signal is sent to the high-orbit satellite;
step S45, the high-orbit satellite receives the test signal, judges the signal-to-noise ratio of the test signal, and when the signal-to-noise ratio of the received test signal is greater than or equal to a preset signal-to-noise ratio threshold value, the signal synchronization test is finished, and the phase synchronization completion identification information is broadcast to the cooperative low-orbit satellite in the corresponding transmission time slot.
Specifically, in an embodiment of the present invention, taking the calculation of the doppler frequency between the ith low-orbit satellite and the high-orbit satellite as an example, the doppler frequency between the low-orbit satellite and the high-orbit satellite is calculated by using the following formula:
wherein (1)>Indicating the Doppler frequency between the ith low-orbit satellite and the high-orbit satellite,/and the like>Indicates the frequency of the synchronization signal transmitted by the high orbit satellite, < >>Representing the three-dimensional speed of the high orbit satellite under the set coordinate system at the moment of calculation,representing the three-dimensional velocity of the ith low-orbit satellite in the set coordinate system at the moment of calculation,/->Representing three-dimensional coordinates of the high orbit satellite under the set coordinate system at the moment of calculation, and +.>Representing three-dimensional coordinates of the ith low orbit satellite in a set coordinate system at the moment of calculation,/->The set coordinate system is, for example, a geocentric inertial coordinate system. The three-dimensional speeds and three-dimensional coordinates of the high-orbit satellite and the low-orbit satellite can be obtained through measurement and control data of ground surface injection, and can also be obtained through a satellite-borne navigation receiver.
In one embodiment of the present invention, taking the ith low-orbit satellite as an example, the frequency correction value is expressed asThe phase jitter value subject to uniform distribution is expressed as +.>. Wherein (1)>Indicating the frequency of tracking by the ith low-orbit satellite,/->Representing the i-th low-orbit satellite generated phase jitter value,/and>the circumference ratio is indicated.
In one embodiment of the present invention, the snr threshold is calculated using the following formula:
wherein (1)>Representing a signal-to-noise threshold, ">Representing the signal-to-noise ratio scaling factor of the signal,/->Indicating the number of co-operating low-orbit satellites in the same transmission time slot, < >>Representing the signal-to-noise ratio of a single low-orbit satellite transmission.
Further, in an embodiment of the present invention, when performing the signal synchronization test, the method further includes:
if the same low-orbit satellite exists in the current transmission time slot and the last transmission time slot for the signal synchronization test, the same low-orbit satellite sends the last acquired frequency correction value to the newly-appearing cooperative low-orbit satellite in the current transmission time slot, takes the frequency reference value acquired in the last signal synchronization test process as the frequency reference value of the test signal, superimposes the phase jitter value acquired in the last signal synchronization test process on the test signal, and sends the test signal to the high-orbit satellite;
calculating an average value of all received frequency correction values by the cooperative low-orbit satellite newly appearing in the current transmission time slot, superposing Doppler frequency of the cooperative low-orbit satellite and the Doppler frequency of the high-orbit satellite obtained by calculation on the average value as a frequency reference value of a test signal, generating a phase jitter value obeying uniform distribution, superposing the phase jitter value on the test signal, and transmitting the test signal to the high-orbit satellite;
the high-orbit satellite receives the test signal, judges the signal-to-noise ratio of the test signal, and when the signal-to-noise ratio of the received test signal is larger than or equal to a preset signal-to-noise ratio threshold value, the signal synchronization test is finished, and the phase synchronization completion identification information is broadcasted to the cooperative low-orbit satellite in the current transmission time slot.
Therefore, the signal synchronization test efficiency can be further improved, and the data processing amount is reduced.
And S5, all the low-orbit satellites participating in cooperative relay communication transmit data to be transmitted to the high-orbit satellites in the corresponding transmission time slots by the high-orbit communication units.
Specifically, after the signal synchronization test is completed, when the low-orbit satellites participating in cooperative relay communication arrive at the corresponding transmission time slots, the high-orbit communication unit sends data to be transmitted which are responsible for the high-orbit satellites.
According to the high-low orbit inter-satellite distributed cooperative communication system and the method, the data of the low orbit satellites are transmitted to the high orbit satellites by utilizing the cooperative relay of the plurality of low orbit satellites, so that the problem that a single low orbit satellite is limited by weak transmission capacity caused by the size and the power consumption of a platform can be effectively solved, the problem of discontinuous transmission caused by the relative motion between the high orbit satellite and the low orbit satellite can be solved, and the capacity, the efficiency and the stability of the high orbit satellite communication are remarkably improved.
It should be noted that in this document, relational terms such as "first" and "second" and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. In this context, "front", "rear", "left", "right", "upper" and "lower" are referred to with respect to the placement state shown in the drawings.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting thereof; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (10)

1. A high-low inter-orbital-satellite distributed cooperative communication system, comprising:
a high orbit satellite which runs on the high orbit;
the low-orbit communication unit is arranged on the high-orbit satellite and can be in communication connection with the high-orbit communication unit, and is used for sending synchronous signals, a cooperative relay time schedule comprising transmission time slots and the low-orbit satellite cooperative in each transmission time slot and phase synchronization completion identification information to the high-orbit communication unit, and receiving data transmission requests comprising the initiating time and the transmission data quantity, test signals and data to be transmitted sent by the high-orbit communication unit;
the cooperative relay calculation unit is arranged on the high-orbit satellite, connected with the pair of low-orbit communication units and used for calculating the cooperative relay time schedule according to the data transmission request;
a plurality of low-orbit satellites operating on low orbits;
the pair of high-orbit communication units are respectively arranged on the low-orbit satellites, and are used for sending a data transmission request to the pair of low-orbit communication units, receiving the synchronous signals and the cooperative relay time sequence table sent by the pair of low-orbit communication units, carrying out signal synchronization test according to the received synchronous signals and the cooperative relay time sequence table, sending test signals to the pair of low-orbit communication units, and sending data to be transmitted to the pair of low-orbit communication units;
and each low-orbit satellite is provided with an inter-satellite interconnection unit, the inter-satellite interconnection units are connected with the pair of high-orbit communication units, and the inter-satellite interconnection units are used for carrying out data transmission between the low-orbit satellites.
2. The high-low inter-orbit satellite distributed cooperative communication method is characterized by comprising the following steps of:
the low-orbit satellite determines a data transmission task, and transmits a data transmission request comprising an initiating time and a transmission data amount to the high-orbit satellite through a high-orbit communication unit;
the high-orbit satellite receives a data transmission request from the low-orbit communication unit and sends the data transmission request to the cooperative relay calculation unit, the cooperative relay calculation unit calculates and acquires a cooperative relay time sequence table comprising transmission time slots and cooperative low-orbit satellites in each transmission time slot according to the data transmission request and sends the cooperative relay time sequence table to the low-orbit communication unit, and the low-orbit communication unit broadcasts a synchronous signal and the cooperative relay time sequence table to each low-orbit satellite;
the low-orbit satellites for sending the data transmission requests determine other low-orbit satellites participating in cooperative relay communication and transmission data responsible for each low-orbit satellite participating in the cooperative relay communication according to the received cooperative relay time sequence table, and send the data to be transmitted to the other low-orbit satellites through an inter-satellite interconnection unit;
before transmitting data to be transmitted to the high-orbit satellite, all low-orbit satellites participating in cooperative relay communication perform signal synchronization test according to the received synchronization signals and a cooperative relay time sequence table;
all low-orbit satellites participating in cooperative relay communication transmit data to be transmitted to the high-orbit satellites in respective corresponding transmission time slots through the high-orbit communication units.
3. The method for distributed cooperative communication between high and low satellites according to claim 2, wherein the step of calculating and acquiring a cooperative relay timing table including transmission time slots and cooperative low-orbit satellites in each transmission time slot according to the data transmission request includes:
calculating the transmission time length according to the transmission data quantity and the data transmission rate between the low-orbit satellite and the high-orbit satellite;
dividing a transmission time slot according to the initiating time and the transmission time length;
determining cooperative low-orbit satellites in each transmission time slot according to the position information of the high-orbit satellites and the low-orbit satellites and the divided transmission time slots;
and generating a cooperative relay time sequence table according to the divided transmission time slots and the cooperative low-orbit satellites in each transmission time slot.
4. The high-low inter-rail-satellite distributed cooperative communication method of claim 3, wherein the transmission duration is calculated using the following formula:
wherein (1)>Indicates the transmission time length,/->Representing the amount of data transferred->Representation ofAn average value of data transmission rates between the low-orbit satellite and the high-orbit satellite.
5. The method for distributed cooperative communication between high and low satellites according to claim 3, wherein the cooperative low-orbit satellites in each transmission slot are determined according to the position information of the high-orbit satellites and the low-orbit satellites and the divided transmission slots in the following manner:
determining the positions of a high-orbit satellite and a low-orbit satellite at the initial time of each transmission time slot, and respectively calculating the pitch angle between the high-orbit satellite and each low-orbit satellite at the initial time of each transmission time slot;
comparing the obtained magnitude relation between each pitch angle and the half-wave beam width of the high-orbit satellite to the low-orbit communication unit, and reserving the pitch angle smaller than the half-wave beam width;
and taking the low-orbit satellite corresponding to the reserved pitch angle as the cooperative low-orbit satellite in the corresponding transmission time slot, and determining the cooperative low-orbit satellite in each transmission time slot.
6. The method of claim 5, wherein the pitch angle between the high-orbit satellite and the low-orbit satellite is calculated using the following formula:
wherein (1)>Representation->Pitch angle between time lower high orbit satellite and i low orbit satellite, +.>Representation ofAt the moment, high orbit satellite is inSetting three-dimensional coordinates in a coordinate system, +.>Representation->Three-dimensional coordinates of the ith low orbit satellite under the moment in a set coordinate system.
7. The method for distributed collaborative communication between high and low orbit satellites according to claim 2 wherein the signal synchronization test is performed by:
before each transmission time slot arrives, a synchronous signal sent by a low-orbit communication unit of the high-orbit satellite is tracked by a Cooks loop to a high-orbit communication unit of the low-orbit satellite in the corresponding transmission time slot, and corresponding frequency is obtained;
the cooperative low-orbit satellite in the corresponding transmission time slot calculates the Doppler frequency of the self and the high-orbit satellite according to the self speed and the high-orbit satellite speed;
the frequency obtained by tracking is Doppler corrected according to the Doppler frequency by the cooperative low orbit satellite in the corresponding transmission time slot, and a frequency correction value is obtained;
the Doppler frequency is superimposed on the obtained frequency correction value as the frequency reference value of the test signal by the cooperative low-orbit satellite in the corresponding transmission time slot, the phase jitter value obeying uniform distribution is generated and superimposed on the test signal, and the test signal is sent to the high-orbit satellite;
the high-orbit satellite receives the test signal, judges the signal-to-noise ratio of the test signal, and when the signal-to-noise ratio of the received test signal is larger than or equal to a preset signal-to-noise ratio threshold value, the signal synchronization test is finished, and the phase synchronization completion identification information is broadcasted to the cooperative low-orbit satellite in the corresponding transmission time slot.
8. The method of claim 7, wherein the doppler frequency between the low-orbit satellite and the high-orbit satellite is calculated using the following formula:
wherein (1)>Indicating the Doppler frequency between the ith low-orbit satellite and the high-orbit satellite,/and the like>Indicates the frequency of the synchronization signal transmitted by the high orbit satellite, < >>Representing the three-dimensional speed of the high orbit satellite under the set coordinate system at the moment of calculation,representing the three-dimensional velocity of the ith low-orbit satellite in the set coordinate system at the moment of calculation,/->Representing three-dimensional coordinates of the high orbit satellite under the set coordinate system at the moment of calculation, and +.>Representing three-dimensional coordinates of the ith low orbit satellite in a set coordinate system at the moment of calculation,/->Indicating the speed of light.
9. The high and low inter-rail satellite distributed collaborative communication method according to claim 8, wherein the signal to noise ratio threshold is calculated using the following equation:
wherein (1)>Representing a signal-to-noise threshold, ">Representing the signal-to-noise ratio scaling factor of the signal,/->Indicating the number of co-operating low-orbit satellites in the same transmission time slot, < >>Representing the signal-to-noise ratio of a single low-orbit satellite transmission signal,/->Indicating the frequency of the ith low orbit satellite tracking.
10. The method for distributed collaborative communication between high and low rail satellites according to claim 7 wherein the signal synchronization test is performed further comprising:
if the same low-orbit satellite exists in the current transmission time slot and the last transmission time slot for the signal synchronization test, the same low-orbit satellite sends the last acquired frequency correction value to the newly-appearing cooperative low-orbit satellite in the current transmission time slot, takes the frequency reference value acquired in the last signal synchronization test process as the frequency reference value of the test signal, superimposes the phase jitter value acquired in the last signal synchronization test process on the test signal, and sends the test signal to the high-orbit satellite;
calculating an average value of all received frequency correction values by the cooperative low-orbit satellite newly appearing in the current transmission time slot, superposing Doppler frequency of the cooperative low-orbit satellite and the Doppler frequency of the high-orbit satellite obtained by calculation on the average value as a frequency reference value of a test signal, generating a phase jitter value obeying uniform distribution, superposing the phase jitter value on the test signal, and transmitting the test signal to the high-orbit satellite;
the high-orbit satellite receives the test signal, judges the signal-to-noise ratio of the test signal, and when the signal-to-noise ratio of the received test signal is larger than or equal to a preset signal-to-noise ratio threshold value, the signal synchronization test is finished, and the phase synchronization completion identification information is broadcasted to the cooperative low-orbit satellite in the current transmission time slot.
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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080001818A1 (en) * 2006-05-18 2008-01-03 Cohen Clark E Low earth orbit satellite providing navigation signals
CN112803983A (en) * 2020-12-30 2021-05-14 南京邮电大学 High-low orbit frequency spectrum sharing method based on formation satellite distributed beam forming
US20210226694A1 (en) * 2020-01-21 2021-07-22 Lockheed Martin Corporation High-data-rate distribution network for leo constellations
CN113644957A (en) * 2021-07-13 2021-11-12 中国电子科技集团公司电子科学研究院 Satellite internet-oriented space-based information relay transmission method
CN114422008A (en) * 2021-12-15 2022-04-29 中国人民解放军军事科学院国防科技创新研究院 Multi-satellite cooperative ground-to-ground communication system and communication method
KR20230125634A (en) * 2022-02-21 2023-08-29 김기식 Data link system between artificial satellites using hybrid wireless access method and method for controlling the same
CN116896408A (en) * 2023-09-11 2023-10-17 国家国防科技工业局重大专项工程中心 Method for carrying out LEO relay data return by utilizing GEO service beam

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080001818A1 (en) * 2006-05-18 2008-01-03 Cohen Clark E Low earth orbit satellite providing navigation signals
US20210226694A1 (en) * 2020-01-21 2021-07-22 Lockheed Martin Corporation High-data-rate distribution network for leo constellations
CN112803983A (en) * 2020-12-30 2021-05-14 南京邮电大学 High-low orbit frequency spectrum sharing method based on formation satellite distributed beam forming
CN113644957A (en) * 2021-07-13 2021-11-12 中国电子科技集团公司电子科学研究院 Satellite internet-oriented space-based information relay transmission method
CN114422008A (en) * 2021-12-15 2022-04-29 中国人民解放军军事科学院国防科技创新研究院 Multi-satellite cooperative ground-to-ground communication system and communication method
KR20230125634A (en) * 2022-02-21 2023-08-29 김기식 Data link system between artificial satellites using hybrid wireless access method and method for controlling the same
CN116896408A (en) * 2023-09-11 2023-10-17 国家国防科技工业局重大专项工程中心 Method for carrying out LEO relay data return by utilizing GEO service beam

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
HUANG, DH: "Quantum Key Distribution Over Double-Layer Quantum Satellite Networks", 《IEEE ACCESS》, vol. 8, no. 10, 21 April 2020 (2020-04-21) *
LIUWEI HUO: "A Dynamic Migration Strategy of SDN Controllers in LEO Networks", 《 SIMULATION TOOLS AND TECHNIQUES 》, 31 March 2022 (2022-03-31) *
杨童;吴雨翔;李明峰;: "全球卫星移动通信星座天基星间链路测控方案", 中国空间科学技术, no. 03, 25 June 2013 (2013-06-25) *
黄思奇等: "天地融合网络架构与传输优化技术", 《天地一体化信息网络》, vol. 4, no. 2, 30 June 2023 (2023-06-30), pages 2 *

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