A dual-satellite autonomous seamless switching method for satellite-missile data link

Abstract

The invention discloses a dual-satellite autonomous seamless switching method applied to a satellite-missile data link, comprising the following steps: S1, a missile determines whether autonomous satellite switching is required according to the distance from each satellite; S2, the missile sends a satellite switching request to a communication satellite, and the communication satellite transmits a satellite switching permission to the missile; S3, the missile enters a satellite switching state after receiving the satellite switching permission transmitted by the communication satellite; S4, the missile entering the satellite switching state sends a network access request to a destination satellite within a satellite-missile communication cycle, and the destination satellite searches in its coverage area, captures and determines the location information of the missile; S5, the destination satellite sends a network access permission to the missile, and the missile completes the satellite switching after receiving the network access permission, communicates with the destination satellite, and exits the network from the communication satellite; the method simplifies the process of switching the satellite network, improves the network switching efficiency, and ensures the stability and reliability of the satellite-missile network.

Description

Technical Field

[0001] The present invention relates to the field of satellite-missile communication, and in particular to a dual-satellite autonomous seamless switching method applied to a satellite-missile data link. Background Art

[0002] At present, node switching technology is mostly used in civil communication services. It does not have good tolerance for the characteristics of high concealment requirements, low speed, high dynamics, and long delay in the field of star-bomb communication. The basic structure of the wireless networking communication technology field in most cases is similar to the star-bomb network architecture, with one base station serving multiple mobile nodes. A base station can cover nodes within a certain range, allowing the nodes to send and receive services with the backbone network. Therefore, in order to cover a wider range, multiple base stations are required. Mobile nodes need to switch frequently between intervals, which puts tremendous pressure on the transmission integrity of real-time services and their data.

[0003] When the missile-borne data link has been networked with the first satellite, it enters the overlapping area covered by the first satellite and the second satellite and moves from the first satellite to the second satellite. As the distance between the missile and the first satellite increases until it is out of the coverage of the first satellite, the missile's network service is interrupted and it needs to re-enter the second satellite network. The process of entering and exiting the network takes too long, and the long-term communication interruption does not meet the missile's use requirements.

[0004] Specifically, Figure 1 As shown in the figure, a schematic diagram of a dual-satellite switching scenario is shown. The missile enters the overlapping area of ​​the dual satellites from the range of the first satellite. As the missile moves, it gradually leaves the coverage area of ​​the first satellite and enters the coverage area of ​​the second satellite. The missile will exit the first satellite network and enter the second satellite network. There are several problems in the dual-satellite switching process of the satellite-missile data link: First, the missile that has entered the first satellite network enters the overlapping area of ​​the two satellites, and in the process of moving from the first satellite to the second satellite, according to the satellite orbit height, the time allowed for the missile to switch the star network may be very short. If the switch is not timely, the link will be interrupted due to the increase in the distance between the missile and the first satellite. Therefore, how to quickly and autonomously judge the star switching and the time required for the star switching is extremely critical; secondly, the second satellite has not established a network with the missile at this time, so it is necessary to obtain the missile position to realize the directional communication of the phased arrays at both ends of the star-missile; thirdly, during the process of switching the star network, the missile will interact with the first satellite and the second satellite at the same time. How to avoid the link terminal problem caused by communication collision; fourthly, during the process of switching the star network, if the switching fails due to link problems, how to ensure the continuous transmission of the star-missile business. Summary of the invention

[0005] The purpose of the present invention is to solve the problem of satellite-bomb service transmission interruption that may occur during dual-satellite switching.

[0006] To achieve the above object, the present invention proposes a dual-satellite autonomous seamless switching method applied to a satellite-missile data link, comprising the following steps:

[0007] S1. The missile determines whether it needs to autonomously cut off the satellite based on the distance to each satellite;

[0008] S2: The missile sends a satellite-cutting request to the communication satellite, and the communication satellite transmits the satellite-cutting permission to the missile;

[0009] S3: If the missile does not receive the satellite-cutting permission, it will continue to maintain the network state and communicate with the communication satellite; if the missile receives the satellite-cutting permission transmitted by the communication satellite, it will enter the satellite-cutting state;

[0010] S4, the missile in the satellite cutting state sends a network access request to the target satellite within the satellite-missile communication cycle, and the target satellite searches in its coverage area, captures and determines the location information of the missile;

[0011] S5. The target satellite sends a network access permission to the missile. After receiving the network access permission, the missile completes the satellite cut-off, communicates with the target satellite, and exits the network from the communication satellite.

[0012] Among them, the missile is synchronized with the star network in absolute time. The missile's onboard data link calculates the real-time position of each satellite in the star network at time t based on the absolute time t and the pre-stored satellite orbit parameters in the star network. When the distance to the target satellite is less than the distance to the communication satellite, the missile determines that it needs to cut satellites, that is, switch from the current communication satellite to the target satellite.

[0013] Among them, the satellite-missile communication cycle includes the target satellite searching for missile network access request time slot, the target satellite transmitting network access permission information time slot, the satellite-missile service transmission time slot, the communication satellite transmitting satellite cutting permission information time slot, and the idle time slot.

[0014] Wherein, the step S2 further comprises the following steps:

[0015] S21. When the missile determines that it needs to cut satellite, it adds a specific flag in the uplink service packet and sends a cut satellite request to the communication satellite through the service transmission sent during the satellite-missile service transmission time slot;

[0016] S22. After receiving the uplink service package uploaded by the missile, the communication satellite determines whether the missile needs to cut satellite through the specific flag in the uplink service package, and determines whether the satellite can be cut and the missile can be replied within the current satellite-missile communication cycle.

[0017] The communication satellite replies to the missile in the time slot when the communication satellite transmits the satellite cutting permission information, and the reply includes: whether the satellite cutting is allowed, and the status information of the communication satellite and the target satellite.

[0018] Among them, step S4 is specifically as follows: the missile's onboard data link sends a network access request signal to the destination satellite during the destination satellite's search for the missile's network access request time slot, wherein the network access request signal includes the missile's position and the network access request, and the network access request signal is repeated n times, where n is the number of beams required to cover the destination satellite area.

[0019] Among them, a protection interval is set between two adjacent network access request signals, and the length of the protection interval is designed according to the transmission delay of the satellite bomb.

[0020] Among them, the protection interval, the number of beams required to cover the target satellite area and the target satellite search missile access request time slot are collaboratively designed.

[0021] Among them, the target satellite determines the beam position with the maximum energy that can receive the missile's network access request signal, and uses it as the beam position of the missile that sends the network access request signal.

[0022] Among them, the network access permission includes the node number assigned by the destination satellite to the missile and the current network status information of the destination satellite; after the missile receives the network access permission, it no longer communicates with the original communication satellite, and sends and receives communications with the destination satellite according to the node number assigned by the destination satellite.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention designs a satellite-missile network switching protocol, optimizes the autonomous switching star network strategy, and combines a rapid access method based on wave position scanning to achieve the original communication satellite network withdrawal and access to the target satellite network without interrupting the service. The missile autonomously determines the timing of network switching, submits a satellite switching application to the original communication satellite, and scans and accesses the new network after obtaining permission.

[0025] The process of switching star networks has been simplified, the network switching efficiency has been improved, and the stability and reliability of the star-bomb network have been ensured;

[0026] After simulation and physical verification, this method can achieve autonomous switching of the star network within 1 second. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of a dual-satellite switching scenario in the present invention;

[0028] Figure 2 It is a diagram of the transmission time slot architecture of the star-bomb network in an embodiment of the present invention;

[0029] Figure 3 A diagram of network access request and wave position search transmission and reception in an embodiment of the present invention;

[0030] Figure 4 This is a simulation diagram of the results of the network access request in an embodiment of the present invention;

[0031] Figure 5 The missile workflow in the embodiment of the present invention;

[0032] Figure 6 This is the satellite workflow in the embodiment of the present invention. DETAILED DESCRIPTION

[0033] The following will be combined with the embodiments of the present invention Figure 1 to Figure 6 , the technical solutions, structural features, objectives achieved and effects in the embodiments of the present invention are described in detail.

[0034] It should be noted that the drawings are in a very simplified form and use non-precise proportions. They are only used to conveniently and clearly assist in explaining the embodiments of the present invention, and are not used to limit the conditions for the implementation of the present invention. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention.

[0035] It should be noted that, in the present invention, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only the elements explicitly listed, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0036] This embodiment proposes a dual-satellite autonomous seamless switching method for satellite-missile data link, based on the satellite-missile data link network switching protocol, autonomous switching satellite network strategy and network access design based on wave position scanning, so as to realize the autonomous and rapid switching of the missile to the satellite-missile network without interrupting the service. Figure 5 and Figure 6 As shown, satellite 1 in the figure is the first satellite, and satellite 2 is the second satellite. The method includes the following steps:

[0037] S1. The missile determines whether it needs to autonomously cut off the satellite based on the distance to each satellite;

[0038] like Figure 1As shown in the figure, when the missile moves from the range of the current communication satellite to the communication range of the next target satellite, enters the communication overlap area of ​​the two satellites and gradually leaves the communication satellite coverage area, the missile calculates the relative distance between the missile and the communication satellite and the target satellite based on its own position and the position of the satellites in the constellation. If the missile determines that the distance to the target satellite is less than the distance to the communication satellite, it needs to autonomously cut off the satellite, as follows:

[0039] When the missile's onboard data link is within the communication range of the communication satellite, it has been connected to the communication satellite and maintained communication with the communication satellite, and has achieved absolute time synchronization with the star network. Therefore, the missile-borne data link can calculate the real-time position (X) of each satellite in the star network at time t based on the absolute time t and the pre-stored satellite orbit parameters in the star network. 1 ,Y 1 ,Z 1 ), (X 2 ,Y 2 ,Z 2 )…(X m ,Y m ,Z m )…, where (X m ,Y m ,Z m ) is the real-time position of the i-th satellite; the missile-borne data link calculates the relative distance d between the missile and each satellite at time t based on the calculated real-time position of each satellite at time t and the missile's own position (x, y, z) fed back by the missile-borne computer 1 ,d 2 …d m …,in It represents the relative distance between the i-th satellite and the missile at time t; the missile-borne data link is based on d 1 ,d 2 …d m …real-time judgment of whether the distance between the missile and other satellites is less than the distance to the current communication satellite. m When it is less than the distance between the missile and the communication satellite, it means that the i-th satellite is closest to the missile. The missile then determines that it should switch from the current communication satellite to the i-th satellite, and the i-th satellite is the target satellite.

[0040] In general, the target satellite can be determined, such as Figure 1 The missile is heading from the first satellite to the second satellite, so it is only necessary to calculate the relative distances between the missile and the communication satellite (the first satellite) and the target satellite (the second satellite) and compare them.

[0041] S2: The missile sends a satellite-cutting request to the communication satellite, and the communication satellite transmits the satellite-cutting permission to the missile;

[0042] S21, at this time, the missile still maintains communication with the first satellite (communication satellite). When the missile determines that satellite cutting is required, a specific flag (for example, a satellite cutting flag) is added to the uplink service packet, and a satellite cutting request is sent to the first satellite through service transmission;

[0043] S22, after receiving the uplink service packet uploaded by the missile, the first satellite determines whether the missile needs to cut satellite based on the specific flag in the uplink service packet, and determines whether the satellite can be cut and the missile can be restored within this period;

[0044] Specifically, Figure 2 As shown in the figure, in order to keep the satellite-missile business transmission uninterrupted, a time-sharing method is adopted to realize the network control information interaction between the satellite and the missile during the dual-satellite switching process, and the time synchronization between the missile and the satellite in the star network. The transmission time of a satellite-missile communication cycle is 1s, including: the target satellite searches for the missile network access request time slot, the target satellite transmits the network permission information time slot, the satellite-missile business transmission time slot, the communication satellite transmits the satellite switching permission information time slot, and the idle time slot.

[0045] Therefore, after the first satellite receives the uplink service packet uploaded by the missile in the satellite-missile service transmission time slot and thus receives the information that the missile needs to cut satellites, it determines whether the missile can cut satellites according to relevant regulations, and replies to the missile in the time slot when the communication satellite downlinks the satellite cutting permission information. The reply information includes: whether the satellite cutting is allowed, and the status information of the first satellite (communication satellite) and the second satellite (destination satellite).

[0046] S3. If the missile's onboard data link does not receive the satellite-cutting permission, the missile continues to maintain the network state and communicate with the first satellite; if the missile receives the satellite-cutting permission transmitted from the first satellite, the missile enters the satellite-cutting state;

[0047] S4, the missile in the satellite cutting state sends a network access request to the second satellite (destination satellite) in a specific time slot within the satellite-missile communication cycle, and the second satellite searches in the coverage area to capture and determine the location information of the missile;

[0048] After the missile enters the satellite cutting state, the onboard data link sends a network access request signal to the second satellite during the target satellite's search for the missile's network access request time slot. The network access request signal includes the missile's position and the network access request. The network access request signal is repeated n times, where n is the number of beams required to cover the second satellite area, thereby ensuring that the second satellite can receive a complete network access request signal at each beam position.

[0049] Specifically, the network access request signal adopts a pseudo-random sequence signal to facilitate the second satellite to discover and locate the missile-borne data link. In this embodiment, the onboard data link of the second satellite adopts a 4×4 phased array with a beam width of 24 degrees. Therefore, the second satellite uses 24 degrees as an airspace scanning interval to scan the entire phased array coverage area, that is, -60° to 60°, a total of 20 airspace scanning spaces, and stays in each airspace scanning interval for 15ms. Considering that the target satellite searches for missile network access request time slot of 300ms, the network access request signal is designed to be repeated 20 times, and the duration of each network access request signal is 9ms. The next network access request signal is repeated after the protection interval. The length of the protection interval is 6ms, that is, the network access request signal is repeated every 15ms.

[0050] Since there is a propagation delay between satellites and missiles, in order to ensure that all traversed wave position values ​​can receive the network access request signal, a protection interval needs to be set. The length of the protection interval is adjusted with different operating conditions and different satellite-missile distances. In this embodiment, the maximum distance of the satellite-missile is 1800km, and the maximum transmission delay is 6ms. Therefore, a 6ms protection interval is added between two adjacent network access request signals. In other embodiments, the protection interval, the number of beams required to cover the second satellite area, and the target satellite search missile network access request time slot are collaboratively designed.

[0051] like Figure 3 As shown, the missile-borne data link sends a network access request signal, the satellite-borne data link receives the network access request signal and records the demodulation information of each wave position. If the demodulation can be correct, the second satellite obtains the missile's position information and the network access request.

[0052] Furthermore, the second satellite determines the beam position with the maximum energy that can receive the missile network access request signal, and uses the beam position as the beam position of the missile that sends the network access request signal.

[0053] like Figure 4 As shown, the network access request signal sent by the missile-borne data link is simulated. The simulation conditions are a spread spectrum code length of 6400 and a code rate of 4.096 MHz. It can be seen that the correlation results have a relatively obvious peak.

[0054] S5, the second satellite sends a network access permission to the missile, and the missile completes the satellite cut-off after receiving the network access permission and communicates with the second satellite;

[0055] The second satellite obtains the missile position according to the demodulated information, and sends a network access permission to the missile's wave position in the network access permission information time slot transmitted by the destination satellite, wherein the network access permission includes the node number assigned to the missile by the second satellite and the current network status information of the second satellite. After receiving the network access permission, the missile considers that it has completed the satellite switching, and will no longer communicate with the first satellite during the communication cycle, and exit the first satellite communication network, and transmit and receive communications with the second satellite according to the node number assigned by the second satellite, thereby completing the switching to the destination satellite and exiting the network from the original communication satellite.

[0056] When the missile exits the first satellite network, it is deemed that the node number assigned to the missile by the first satellite is released, and the first satellite can reallocate the node number.

[0057] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A dual-satellite autonomous seamless handover method applied to a satellite-missile data link, characterized in that, it includes the following steps: S1. The missile determines whether it needs to autonomously switch satellites according to the distances from each satellite; S2. The missile sends a satellite handover request to the communication satellite, and the communication satellite transmits a satellite handover permission to the missile; S3. If the missile does not receive the satellite handover permission, it continues to maintain the network state and communicate with the communication satellite; if the missile receives the satellite handover permission transmitted by the communication satellite, it enters the satellite handover state; S4. The missile in the satellite handover state sends an access request to the target satellite during the satellite-missile communication cycle. The target satellite searches within its coverage area, captures and determines the position information of the missile; S5. The target satellite sends an access permission to the missile. After receiving the access permission, the missile completes the satellite handover, communicates with the target satellite, and withdraws from the network of the communication satellite; wherein, the on-board data link of the target satellite is a phased array; The satellite-missile communication cycle includes a time slot for the target satellite to search for the missile access request, a time slot for the target satellite to transmit the access permission information, a time slot for satellite-missile service transmission, a time slot for the communication satellite to transmit the satellite handover permission information, and an idle time slot.

2. A dual-satellite autonomous seamless handover method applied to a satellite-missile data link according to claim 1, characterized in that, The missile is absolutely time-synchronized with the satellite network. The on-board data link of the missile calculates the real-time positions of each satellite in the satellite network at time t based on the absolute time t and the pre-stored satellite orbit parameters in the satellite network. When the distance from the target satellite is less than the distance from the communication satellite, the missile determines that it needs to switch satellites, that is, switch from the current communication satellite to the target satellite.

3. A dual-satellite autonomous seamless handover method applied to a satellite-missile data link according to claim 2, characterized in that, The step S2 further includes the following steps: S21. When the missile determines that it needs to switch satellites, add a specific flag to the uplink service packet and send a satellite handover request to the communication satellite through the service transmission sent during the satellite-missile service transmission time slot; S22. After receiving the uplink service packet uploaded by the missile, the communication satellite determines whether the missile needs to switch satellites through the specific flag in the uplink service packet, and determines whether it can switch satellites within the current satellite-missile communication cycle and replies to the missile.

4. A dual-satellite autonomous seamless handover method applied to a satellite-missile data link according to claim 3, characterized in that, The communication satellite replies to the missile during the time slot for the communication satellite to transmit the satellite handover permission information. The reply includes: whether satellite handover is allowed, and the status information of the communication satellite and the target satellite.

5. A dual-satellite autonomous seamless handover method applied to a satellite-missile data link according to claim 4, characterized in that, The step S4 is specifically: the on-board data link of the missile sends an access request signal to the target satellite during the time slot for the target satellite to search for the missile access request. The access request signal includes the position of the missile and the access request, and the access request signal is repeated n times, where n is the number of beams required to cover the area of the target satellite.

6. A dual-satellite autonomous seamless handover method applied to a satellite-missile data link according to claim 5, characterized in that, A guard interval is set between two adjacent access request signals, and the length of the guard interval is designed according to the satellite-missile transmission delay.

7. A dual-satellite autonomous seamless switching method for satellite-missile data link as claimed in claim 6, It is characterized in that The protection interval, the number of beams required to cover the target satellite area, and the target satellite search missile network request time slot are collaboratively designed.

8. A dual-satellite autonomous seamless switching method for satellite-missile data link as claimed in claim 7, It is characterized in that The target satellite determines the beam position with the maximum energy that can receive the missile's network access request signal, and uses it as the beam position of the missile that sends the network access request signal.

9. A dual-satellite autonomous seamless switching method for satellite-missile data link as claimed in claim 8, It is characterized in that The network access permission includes the node number assigned by the target satellite to the missile and the current network status information of the target satellite; After receiving the network access permission, the missile will no longer communicate with the original communication satellite, but will send and receive communications with the destination satellite according to the node number assigned by the destination satellite.

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