CN113489530A - Method for synchronously switching feeder links in low-earth-orbit constellation satellite communication system - Google Patents
Method for synchronously switching feeder links in low-earth-orbit constellation satellite communication system Download PDFInfo
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Abstract
The invention discloses a method for synchronously switching feeder links in a low earth orbit constellation satellite communication system, which comprises the following steps: the clock source synchronization of the operation control system, the low-orbit satellite, the source gateway station A and the target gateway station B is realized by utilizing a global positioning time service system; the operation control system comprehensively plans a satellite feed link switching schedule according to the ephemeris data, the gateway station health state and load condition, feed interference avoidance and weather, and issues the schedule to the gateway station and the satellite; the gateway station system calculates transmission delay and relative Doppler frequency offset according to the ephemeris data, adjusts the signal receiving and transmitting timing and frequency of the gateway station, and adjusts an antenna to point to wait for the satellite to enter the visual field; the gateway station system captures the satellite, calculates transmission delay and relative Doppler frequency offset in real time according to satellite ephemeris data, and adjusts the receiving and transmitting timing and frequency of the gateway station signal in real time. The invention reduces the service interruption caused by the switching of the feed link and ensures the consistent signal characteristics of the satellite reaching the user terminal.
Description
Technical Field
The invention belongs to the technical field of satellite communication, and particularly relates to a method for synchronously switching feeder links in a low-earth-orbit constellation satellite communication system.
Background
1. Low earth orbit constellation satellite communication system
The low-orbit constellation satellite communication system is a satellite communication system which transmits signals through a low-orbit constellation. Currently, the low orbit constellation satellite communication systems built or already built in the world mainly comprise starlink, O3B, OneWeb, Telesat and the like, and China mainly comprises systems such as rainbow clouds and swan gooses. Generally, a low earth constellation satellite communication system is composed of three parts, namely a space section, a ground section and an application section, as shown in fig. 1:
(1) space segment
The space segment is comprised of a constellation of low orbit satellites. The satellite constellation is a collection of satellites which can normally work when being launched into orbit, and is generally a satellite network formed by a plurality of satellite rings which are configured in a certain mode. The low-orbit satellite constellation is a low-orbit satellite network composed of a plurality of low-orbit satellites, as shown in fig. 2.
(2) Ground segment
The ground segment is used as an important component of the low-earth constellation satellite communication system, completes the functions of satellite load management, service processing, network management, operation management, cross-country service settlement and the like of the low-earth constellation satellite communication system, is responsible for interconnection and intercommunication of the low-earth constellation satellite communication system and other systems, and mainly comprises an operation control center, a global operation service center and gateway stations distributed in all parts of the world. a) The operation control center: the operation control center is an operation control center for short, is a core component and a management center of operation and maintenance control of the low-earth constellation satellite communication system, provides a centralized, unified, comprehensive and automatic platform for system control and application management, and ensures safe, stable and reliable operation of a constellation and ground gateway station network. The system mainly completes the functions of satellite load management, satellite-ground resource operation condition and satellite-ground feeder link state monitoring, gateway station system task planning and the like. b) Global operation service center: the global operation service center is an important part for supporting the global operation of the satellite communication system with low earth orbit constellation. The global operation service center is connected with the comprehensive network management and operation support system of each country, mainly completes the functions of global settlement, gateway station network monitoring and the like, and ensures the safe and stable operation of the global network. c) Gateway station system: the gateway station system provides services such as communication, service, operation, management and the like for the low earth constellation satellite communication system, and has the functions of system resource management, user authentication and encryption, service routing and exchange, service, local network operation and the like. The satellite communication system mainly comprises gateway stations deployed in various station building countries or regions and communication networks among the gateway stations, and is a main ground facility of the satellite communication system with the low-earth constellation. The low earth constellation satellite communication system can be interconnected with the ground PLMN, PSTN, Internet and other private networks.
(3) Application segment
The application section is composed of various fixed and mobile terminals distributed in the coverage range of low earth orbit constellation wave beams, the terminals are portals and application platforms of users accessing a low earth orbit constellation satellite communication system and are used for establishing data transmission links between the users and the satellites, and each terminal has the switching capacity among the wave beams, the satellites and the gateway stations and can provide continuous service for the users.
2. Feeder link
In a satellite mobile communication system, a link between a satellite terminal and a satellite is defined to be a user link, and a link between a gateway station and the satellite is defined to be a feeder link; the link from the gateway station to the satellite terminal is a forward link and the link from the satellite terminal to the gateway station is a return link. Generally, in a low-orbit constellation, each satellite is provided with two independent feeder link antennas, and in the process of high-speed movement of the satellite relative to the ground, the switching of the feeder links of the satellite between two gateway stations is realized, so that the data transmission of the feeder links is not interrupted.
3. Handover
The conventional handover is a process in which when a terminal moves from one coverage area of a base station to another coverage area of the base station during a call or communication quality is degraded due to external interference, an original communication channel must be changed and switched to a new idle communication channel to continue the call. From terrestrial mobile communication systems to GEO satellite communication systems, handover has been an operation between a user and a base station/gateway station. However, in low earth satellite communication systems, since the satellite moves at a high speed relative to the ground and the ground gateway station is often fixed in a certain position, there is a link switching between the satellite and the gateway station, called "feeder link switching", as shown in fig. 3.
In a low-earth-orbit satellite communication system, an operation control system comprehensively plans a satellite feed link switching plan according to information such as ephemeris data, the health state and the load condition of a gateway station, feed interference avoidance and the like, and issues the plan to the gateway station and a satellite, the gateway station adjusts a ground antenna to point to an orbit where the satellite is located according to the planning time, the satellite adjusts a feed antenna to point to a target gateway station according to the planning time, the moment to be switched comes, and the satellite and the target gateway station establish a feed link to realize feed link switching. Feeder link switching can be divided into asynchronous switching and synchronous switching depending on whether time-frequency synchronization of the link is achieved between two gateway stations. Asynchronous switching means that the time and frequency of feeder link signals between a source gateway station and a target gateway station and between satellites are not synchronous, all users under the satellites with the feeder link switching need to be resynchronized with the target gateway station for a transparent forwarding satellite, and at the moment, a terminal initiates random access collectively to realize uplink synchronization with the gateway station, so that congestion is caused, and the switching users are seriously lost. The synchronous switching refers to the time frequency synchronization of the feeder link signals between the gateway station and the target gateway station and between the satellite, the mechanism can effectively avoid the resynchronization of the user and the gateway station, and reduce the service interruption caused by the feeder link switching as much as possible.
Factors such as invisibility of the gateway station and the current service satellite, interference avoidance of a feed link, rain attenuation and the like can trigger switching of a satellite feed link, the feed link bears all users of the current service satellite, switching of the feed link triggers switching of all users, and parameter synchronization of a user link layer and an application layer is further introduced. How to adopt efficient and reasonable switching of the group users is a problem to be solved by the feeder link. Patent CN 201910782564.8 discloses a method, device and apparatus for switching feeder link and user equipment of home satellite, which adopts a typical feeder link asynchronous switching mechanism, and does not make any adjustment to gateway station in the switching process, so that a large number of satellite terminals cause signaling congestion due to uplink synchronization after the feeder link is switched. Patent CN 202010105732.2 discloses a terminal reselection method and device for feeder link switching, when a satellite is about to have feeder link switching, the link information of a target gateway station is broadcasted to the terminal user in advance, and after the feeder link switching, the terminal adjusts the synchronization parameter according to the link information of the target gateway station, thereby implementing resynchronization with the network side, and the system implementation is complex. Patent CN 201910675491.2 discloses a satellite cross-gateway station feeder link switching method based on user switching limitation and offloading, wherein before the satellite is about to have feeder link switching, the user is offloaded to a nearby satellite, so as to avoid signaling congestion caused by uplink synchronization of a large number of satellite terminals after the feeder link switching, but possibly causing the burden of nearby satellite resources, and when the nearby satellite resources are insufficient, the terminals cannot be normally switched to the nearby satellite and communication is interrupted.
To sum up, the existing published documents all belong to a satellite feeder link asynchronous switching mechanism, a terminal is required to perform uplink and downlink resynchronization according to target gateway station information provided by a network side, in order to ensure the probability of successful resynchronization of the terminal, the system needs to broadcast information with sufficient precision, the implementation complexity of terminal equipment and the network burden are increased, and meanwhile, in the uplink resynchronization process of a large number of terminals, distance measurement is often required, so that the signaling processing congestion of a gateway station system is caused.
Disclosure of Invention
The invention aims to provide a method for synchronously switching feeder links in a low-earth constellation satellite communication system, which avoids resynchronization between a user and a gateway station, reduces service interruption caused by switching feeder links, and ensures consistent signal characteristics of a satellite reaching a user terminal.
The technical solution for realizing the purpose of the invention is as follows: a method for synchronously switching feeder links in a low earth constellation satellite communication system comprises the following steps:
adopting a feed link time synchronous switching mechanism, calculating transmission delay by the gateway station according to ephemeris data, and adjusting the receiving and transmitting timing in real time to ensure that two stations participating in feed link switching are aligned in uplink and downlink timing on the satellite;
and a frequency synchronous switching mechanism of the feeder link is adopted, the gateway station calculates the Doppler frequency relative to a reference point according to ephemeris data, and the receiving and transmitting frequency deviation is adjusted in real time, so that the frequencies of two stations participating in the switching of the feeder link at the relative reference point are consistent.
Further, the feeder link switching flow is as follows:
step 2, the operation control system comprehensively plans a satellite feed link switching schedule according to the information of ephemeris data, the health state and the load condition of the gateway station, feed interference avoidance and weather, and issues the schedule to the gateway station and the satellite;
step 3, the gateway station system calculates transmission delay and relative Doppler frequency offset according to ephemeris data, adjusts the signal receiving and transmitting timing and frequency of the gateway station, and adjusts an antenna to point to wait for the satellite to enter the visual field;
and 4, capturing the satellite by the gateway station system, calculating transmission delay and relative Doppler frequency offset in real time according to satellite ephemeris data, and adjusting the signal receiving and transmitting timing and frequency of the gateway station in real time.
Further, the satellite feeder link switching schedule table in step 2 includes 5 columns, which are sequentially a serial number, a route segment, a running time, a gateway station to which the satellite belongs, and a remark, where the serial number is sequentially increased from 1 line by line, the corresponding route segment is arranged line by line in a manner of from a position 1 to a position 2, from a position 2 to a position 3, and from a position 3 to a position 4, and the corresponding running time is T1To T2Time period, T2To T3Time period, T3To T4The time periods are arranged row by row, and the gateway stations belonging to the corresponding satellites are arranged row by row in the manner of A, B, C.
Further, at T1To T2In the time period, the gateway station A is in a working state, takes over the low orbit satellite S in the position 1 and provides service for the user through the satellite; time of arrival T2 ’From T2 ’To T2In time periods, the gateway station B is in a feed link switching preparation state, according to the satellite of the satellite SBy following the information, calculating the transmission delay T between the satellite S and the satellitedelayAnd adjusting the transmit-receive start time of the gateway station, assuming that the time reference of the current gateway station is TbaseWherein the transmission start time is TXof＝Tbase-TdelayThe reception start time is RXof＝Tbase+TdelayCalculating the Doppler frequency offset F between the central point of the satellite S or user beamoffsetAnd adjusting the transceiving frequency of the gateway station, and adjusting the antenna to point to the position 2 where the low-earth satellite S is to arrive, and waiting for the satellite to enter the view of the antenna.
Further, T when the switching time comes2The gateway station B tracks the low-orbit satellite, opens a transceiving channel, enters a working state, calculates transmission delay and Doppler frequency offset according to the real-time position of the satellite, adjusts transceiving timing and frequency of the gateway station B in real time, and the gateway station A is in a switching preparation state of the next satellite, adjusts transceiving starting time and antenna pointing direction to prepare for tracking the next low-orbit satellite and waits for the next satellite to enter the visual field of the gateway station.
Compared with the prior art, the invention has the following remarkable advantages: (1) a feed link synchronous switching mechanism without terminal participation is adopted, and through synchronization among nodes such as a network side satellite, a gateway station, operation control and the like, the consistency of signal characteristics of the satellite reaching a user terminal is ensured; (2) in the switching process of the satellite feed link, the link synchronization between related nodes inside the network side is realized, the user terminal is noninductive in the whole process, no operation is required, and the terminal implementation is simplified; (3) the signal characteristics for reaching the terminal are consistent, the user terminal does not need to carry out uplink resynchronization, and the possibility of signaling congestion of a gateway station system is reduced.
Drawings
Fig. 1 is a schematic diagram of a low earth constellation satellite communication system.
Fig. 2 is a diagram of a low-orbit constellation.
Fig. 3 is a schematic diagram of satellite feeder link switching.
Fig. 4 is a schematic diagram of synchronous switching of feeder links in a low earth constellation satellite communication system.
Fig. 5 is a timing relationship diagram of the time of feeder link switching T1.
Fig. 6 is a feeder link synchronous switching flow chart.
Detailed Description
Factors such as invisibility of the gateway station and the current service satellite, interference avoidance of a feeder link, rain attenuation and the like can trigger switching of a satellite feeder link, the feeder link bears all users of the current service satellite, switching of the feeder link triggers switching of all users, parameter synchronization of a user link layer and an application layer is further introduced, and the problem that switching of group users needs to be solved by the feeder link is solved efficiently and reasonably.
The invention discloses a method for synchronously switching feeder links in a low earth constellation satellite communication system, which comprises the following steps:
adopting a feed link time synchronous switching mechanism, calculating transmission delay by the gateway station according to ephemeris data, and adjusting the receiving and transmitting timing in real time to ensure that two stations participating in feed link switching are aligned in uplink and downlink timing on the satellite;
and a frequency synchronous switching mechanism of the feeder link is adopted, the gateway station calculates the Doppler frequency relative to a reference point according to ephemeris data, and the receiving and transmitting frequency deviation is adjusted in real time, so that the frequencies of two stations participating in the switching of the feeder link at the relative reference point are consistent.
Further, the feeder link switching flow is as follows:
step 2, the operation control system comprehensively plans a satellite feed link switching schedule according to the information of ephemeris data, the health state and the load condition of the gateway station, feed interference avoidance and weather, and issues the schedule to the gateway station and the satellite;
step 3, the gateway station system calculates transmission delay and relative Doppler frequency offset according to ephemeris data, adjusts the signal receiving and transmitting timing and frequency of the gateway station, and adjusts an antenna to point to wait for the satellite to enter the visual field;
and 4, capturing the satellite by the gateway station system, calculating transmission delay and relative Doppler frequency offset in real time according to satellite ephemeris data, and adjusting the signal receiving and transmitting timing and frequency of the gateway station in real time.
Further, the satellite feeder link switching schedule table in step 2 includes 5 columns, which are sequentially a serial number, a route segment, a running time, a gateway station to which the satellite belongs, and a remark, where the serial number is sequentially increased from 1 line by line, the corresponding route segment is arranged line by line in a manner of from a position 1 to a position 2, from a position 2 to a position 3, and from a position 3 to a position 4, and the corresponding running time is T1To T2Time period, T2To T3Time period, T3To T4The time periods are arranged row by row, and the gateway stations belonging to the corresponding satellites are arranged row by row in the manner of A, B, C.
Further, at T1To T2In the time period, the gateway station A is in a working state, takes over the low orbit satellite S in the position 1 and provides service for the user through the satellite; time of arrival T2 ’From T2 ’To T2In the time period, the gateway station B is in a feed link switching preparation state, and the transmission delay T between the gateway station B and the satellite S is calculated according to the ephemeris information of the satellite SdelayAnd adjusting the transmit-receive start time of the gateway station, assuming that the time reference of the current gateway station is TbaseWherein the transmission start time is TXof＝Tbase-TdelayThe reception start time is RXof＝Tbase+TdelayCalculating the Doppler frequency offset F between the central point of the satellite S or user beamoffsetAnd adjusting the transceiving frequency of the gateway station, and adjusting the antenna to point to the position 2 where the low-earth satellite S is to arrive, and waiting for the satellite to enter the view of the antenna.
Further, T when the switching time comes2The gateway station B tracks the low orbit satellite and opens the receiving and transmitting channel, the gateway station B enters the working state, calculates the transmission delay and Doppler frequency offset according to the real-time position of the satellite, and adjusts the receiving and transmitting timing and frequency of the gateway station B in real time, and the gateway station A is in the switching preparation state of the next satelliteAnd adjusting the transmitting and receiving starting time and the pointing direction of the antenna to prepare for tracking the next low-orbit satellite and waiting for the next satellite to enter the visual field of the gateway station.
The invention is described in further detail below with reference to the figures and the embodiments.
Examples
The low-orbit satellites operate on a relatively fixed orbit, and the operation control system can obtain accurate ephemeris information of all the satellites of the low-orbit constellation through the measurement and control station. On one hand, the gateway station can calculate the distance, transmission delay and the like of the satellite relative to the ground at a certain moment by using the ephemeris data, adjust the transceiving starting time of the gateway station in real time, and ensure that the transceiving starting time of the uplink and downlink signals of the feeder link is aligned on the satellite, thereby ensuring that the transceiving starting time of the link signals of the satellite user is aligned; on the other hand, the gateway station may also use the ephemeris data to calculate the doppler shift of the satellite relative to a common reference point (on the satellite or the user beam center point) at a certain time, so as to adjust the transceiving frequency of the gateway station in real time, and ensure that the signals transmitted on the satellite user link are synchronized at a certain reference point (on the satellite or the user beam center point). In this way, the signals of the two gateway stations participating in the switching of the satellite feeder link can be kept time and frequency synchronized on the satellite, and the user does not need to resynchronize in the switching process. The specific scheme is shown in figure 4.
The synchronization of a clock source is realized by utilizing a global positioning time service system such as a GPS/Beidou, an operation control system, a low-orbit satellite, a source gateway station A and a target gateway station B; the operation control system comprehensively plans a satellite feed link switching plan table according to satellite ephemeris data, gateway station health state and load condition, feed interference avoidance, weather and other information, and issues the plan to the gateway station A, B and the satellite.
TABLE 1 resource Allocation Schedule for a satellite S feeder link
| Serial number | Route segmentation | Run time | Gateway station to which satellite belongs | Remarks for |
| 1 | |
T1→T2 | A | |
| 2 | Position 2 → position 3 | T2→T3 | B | |
| 3 | Position 3 → position 4 | T3→T4 | C | |
| … | … | … | … |
At T1To T2In the time period, the gateway station A is in a working state, takes over the low orbit satellite S in the position 1 and provides service for the user through the satellite; time of arrival T2 ’From T2 ’To T2In the time period, the gateway station B is in a feed link switching preparation state, and the transmission delay T between the gateway station B and the satellite S is calculated according to the ephemeris information of the satellite SdelayAnd adjusting the transmit-receive start time of the gateway station, assuming that the time reference of the current gateway station is TbaseWherein the transmission start time is TXof＝Tbase-TdelayThe reception start time is RXof＝Tbase+TdelayCalculating the Doppler frequency offset F between the central point of the satellite S or user beamoffsetAdjusting the receiving and sending frequency of the gateway station, and adjusting the antenna of the gateway station to point to a position 2 where the low-orbit satellite S is to arrive to wait for the satellite to enter the view of the antenna; when the switching time comes T2The gateway station B tracks the low-orbit satellite, opens a transceiving channel, enters a working state, calculates transmission delay and Doppler frequency offset according to the real-time position of the satellite, adjusts transceiving timing and frequency of the gateway station B in real time, and the gateway station A is in a switching preparation state of the next satellite, adjusts transceiving starting time and antenna pointing direction to prepare for tracking the next low-orbit satellite and waits for the next satellite to enter the visual field of the gateway station. Fig. 5 is a timing relationship diagram of the time of feeder link switching T1.
The invention relates to a method for synchronously switching feeder links in a low-earth constellation satellite communication system, wherein the switching process of the feeder links is as shown in figure 6:
the synchronization of a clock source is realized by utilizing a global positioning time service system such as a GPS/Beidou and the like, an operation control system, a low-orbit satellite, a source gateway station A and a target gateway station B by utilizing a global positioning time service system such as a GPS/Beidou and the like;
the operation control system comprehensively plans a satellite feed link switching schedule according to ephemeris data, the health state and load condition of the gateway station, feed interference avoidance, weather and other information, and issues the schedule to the gateway station and the satellite;
the gateway station system calculates transmission delay and relative Doppler frequency offset according to the ephemeris data, adjusts the signal receiving and transmitting timing and frequency of the gateway station, and adjusts an antenna to point to wait for the satellite to enter the visual field;
the gateway station system captures the satellite, calculates transmission delay and relative Doppler frequency offset in real time according to satellite ephemeris data, and adjusts the receiving and transmitting timing and frequency of the gateway station signal in real time.
In summary, the key technologies of the present invention include the following: 1. a feed link time synchronous switching mechanism is adopted, the gateway station calculates transmission delay according to ephemeris data, and the receiving and transmitting timing is adjusted in real time, so that the two stations participating in feed link switching are ensured to be aligned in uplink and downlink timing on the satellite; 2. by adopting a frequency synchronous switching mechanism of the feeder link, the gateway station calculates the Doppler frequency relative to a reference point (on-board and user beam center point) according to ephemeris data, adjusts the deviation of the receiving and transmitting frequency in real time and ensures that the frequencies of two stations participating in the switching of the feeder link at the relative reference point are consistent.
The invention adopts a feed link synchronous switching mechanism without terminal participation, and ensures the consistent signal characteristics of the satellite reaching the user terminal through the synchronization among the nodes of the network side satellite, the gateway station, the operation control and the like; in the switching process of the satellite feed link, the link synchronization between related nodes inside the network side is realized, the user terminal is noninductive in the whole process, no operation is required, and the terminal implementation is simplified; the signal characteristics for reaching the terminal are consistent, the user terminal does not need to carry out uplink resynchronization, and the possibility of signaling congestion of a gateway station system is reduced.
Claims (5)
1. A method for synchronously switching feeder links in a low earth constellation satellite communication system is characterized by comprising the following steps:
adopting a feed link time synchronous switching mechanism, calculating transmission delay by the gateway station according to ephemeris data, and adjusting the receiving and transmitting timing in real time to ensure that two stations participating in feed link switching are aligned in uplink and downlink timing on the satellite;
and a frequency synchronous switching mechanism of the feeder link is adopted, the gateway station calculates the Doppler frequency relative to a reference point according to ephemeris data, and the receiving and transmitting frequency deviation is adjusted in real time, so that the frequencies of two stations participating in the switching of the feeder link at the relative reference point are consistent.
2. The method of claim 1, wherein the feeder link switching procedure comprises:
step 1, synchronizing an operation control system, a low-orbit satellite, a source gateway station A and a target gateway station B clock source by using a GPS/Beidou global positioning time service system;
step 2, the operation control system comprehensively plans a satellite feed link switching schedule according to the information of ephemeris data, the health state and the load condition of the gateway station, feed interference avoidance and weather, and issues the schedule to the gateway station and the satellite;
step 3, the gateway station system calculates transmission delay and relative Doppler frequency offset according to ephemeris data, adjusts the signal receiving and transmitting timing and frequency of the gateway station, and adjusts an antenna to point to wait for the satellite to enter the visual field;
and 4, capturing the satellite by the gateway station system, calculating transmission delay and relative Doppler frequency offset in real time according to satellite ephemeris data, and adjusting the signal receiving and transmitting timing and frequency of the gateway station in real time.
3. The method according to claim 2, wherein the satellite feeder link switching schedule table in step 2 includes 5 columns, which are sequentially a serial number, a route segment, a running time, a gateway station to which the satellite belongs, and a remark, wherein the serial number is sequentially increased from 1 line by line, the corresponding route segment is arranged line by line in a manner from position 1 to position 2, position 2 to position 3, and position 3 to position 4, and the corresponding running time is T1To T2Time period, T2To T3Time period, T3To T4The time periods are arranged row by row, and the gateway stations belonging to the corresponding satellites are arranged row by row in the manner of A, B, C.
4. The method of claim 3, wherein T is T1To T2In the time period, the gateway station A is in a working state, takes over the low orbit satellite S in the position 1 and provides service for the user through the satellite; time of arrival T2When, from T2To T2In the time period, the gateway station B is in a feed link switching preparation state, and the transmission delay T between the gateway station B and the satellite S is calculated according to the ephemeris information of the satellite SdelayAnd adjusting the transmit-receive start time of the gateway station, assuming that the time reference of the current gateway station is TbaseWherein the transmission start time is TXof＝Tbase-TdelayThe reception start time is RXof＝Tbase+TdelayCalculating the Doppler frequency offset F between the central point of the satellite S or user beamoffsetAnd adjusting the transceiving frequency of the gateway station, and adjusting the antenna to point to the position 2 where the low-earth satellite S is to arrive, and waiting for the satellite to enter the view of the antenna.
5. The method of claim 3 or 4, wherein T is the time when the switching time comes2The gateway station B tracks the low-orbit satellite, opens a transceiving channel, enters a working state, calculates transmission delay and Doppler frequency offset according to the real-time position of the satellite, adjusts transceiving timing and frequency of the gateway station B in real time, and the gateway station A is in a switching preparation state of the next satellite, adjusts transceiving starting time and antenna pointing direction to prepare for tracking the next low-orbit satellite and waits for the next satellite to enter the visual field of the gateway station.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114157344A (en) * | 2021-12-09 | 2022-03-08 | 成都天奥集团有限公司 | Method for supporting lossless switching of satellite feed link |
| CN114401035A (en) * | 2022-01-21 | 2022-04-26 | 中国电子科技集团公司第五十四研究所 | Gateway station processing resource pool scheduling method based on-satellite processing |
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| CN114157344A (en) * | 2021-12-09 | 2022-03-08 | 成都天奥集团有限公司 | Method for supporting lossless switching of satellite feed link |
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| CN116015411A (en) * | 2022-12-16 | 2023-04-25 | 中电防务科技有限公司 | High dynamic terminal and switching method for satellite mobile communication system |
| CN116155359A (en) * | 2023-02-21 | 2023-05-23 | 南京熊猫汉达科技有限公司 | Switching method between low orbit constellation satellites |
| CN117676811A (en) * | 2024-01-04 | 2024-03-08 | 广州新一代芯片技术有限公司 | Terminal positioning method, system and device applied to mobile cellular communication system |
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