阅读说明：本技术 面向高通量卫星的多信关站跳波束同步方法及系统 (Multi-gateway station beam hopping synchronization method and system for high-throughput satellite ) 是由 李军 翟盛华 惠腾飞 龚险峰 王大庆 于 2021-06-29 设计创作，主要内容包括：本发明公开了面向高通量卫星的多信关站跳波束同步方法及系统。首先地面信关站组主要包括网络控制中心、主信关站和多个从信关站,每个信关站进行业务信号以及同步控制信号的产生。然后,跳波束卫星载荷中的前向链路转发器将每个信关站发送的业务信号和控制信号分离,其中业务信号送给后端的功率放大链路,同步控制信号送给跳波束控制器进行处理,跳波束控制器对多个信关站的同步控制信号进行解析和时间比对,提取从信关站与主信关站的时间误差,同时根据解析出来的跳波束控制指令对跳波束后端的开关链路进行控制。该方法波束跳变同步流程简单,同步时间快,星上处理简单可靠,且不依赖具体的业务通信体制。(The invention discloses a multi-gateway station beam hopping synchronization method and system for a high-throughput satellite. Firstly, the ground gateway station group mainly comprises a network control center, a master gateway station and a plurality of slave gateway stations, and each gateway station generates a service signal and a synchronous control signal. Then, a forward link transponder in the beam hopping satellite load separates a service signal and a control signal sent by each gateway station, wherein the service signal is sent to a power amplification link at the rear end, a synchronous control signal is sent to a beam hopping controller for processing, the beam hopping controller analyzes and compares time of the synchronous control signals of a plurality of gateway stations, extracts time errors of a slave gateway station and a master gateway station, and controls a switch link at the rear end of the beam hopping station according to an analyzed beam hopping control instruction. The method has the advantages of simple beam hopping synchronization process, quick synchronization time, simple and reliable satellite processing and no dependence on a specific service communication system.)

1. A multi-gateway station beam hopping synchronization method facing a high-throughput satellite, wherein the high-throughput satellite comprises a network control center, a main gateway station and a plurality of slave gateway stations, the network control center and the plurality of gateway stations have information intercommunication capability, and beam control coordination among the plurality of gateway stations is realized, and the method is characterized by comprising the following steps:

s1, each gateway station generates a synchronous pulse according to the self time reference and the preset synchronous period, and sends a synchronous control signal with a synchronous signaling through a control channel at the starting time of the synchronous pulse; the starting time of the synchronous control signal is strictly synchronous with the starting time of the synchronous pulse; the time signaling comprises time frame counting information, and the time frame counting information is a local synchronous pulse counting value corresponding to the starting time of the current synchronous control signal;

s2, when the satellite receives the synchronous control signal of each gateway station, the synchronous control signal is demodulated and analyzed to obtain the time frame counting information, and the synchronous pulse of each gateway station is recovered, and the starting edge of the synchronous pulse is aligned with the starting time of the received synchronous control signal;

s3, the satellite generates satellite synchronization pulses and time frame counting information according to the same preset synchronization period according to the self time reference;

s4, the satellite compares the synchronization pulse and the time frame counting information of the satellite with the synchronization pulse and the time frame counting information of the main gateway station to obtain the time deviation between the main gateway station and the satellite; comparing the synchronization pulse and the time frame counting information of the slave gateway station with the synchronization pulse and the time frame counting information of the master gateway station to obtain the time deviation between the slave gateway station and the master gateway station;

s5, the satellite frames the time deviation between each slave gateway station and the master gateway station and the time deviation between the master gateway station and the satellite, and broadcasts the frames to each slave gateway station and the master gateway station through a downlink;

s6, the network control center corrects the time of each gateway station according to the time deviation between each slave gateway station and the master gateway station and the time deviation between the master gateway station and the satellite, so that each slave gateway station is synchronous with the master gateway station, and the master gateway station is synchronous with the time on the satellite.

2. The method for beam hopping synchronization between multiple gateway stations facing high throughput satellite according to claim 1, wherein said step S4 is:

the specific calculation method of the time deviation between the main gateway station and the satellite comprises the following steps:

the time difference between the start time of the synchronization pulse on the main gateway station and the satellite plus the counting difference between the main gateway station and the satellite time frame is multiplied by the preset synchronization period.

The specific calculation method of the time deviation between the slave gateway station and the master gateway station comprises the following steps:

the time difference of the starting time of the synchronous pulse of the slave gateway station and the master gateway station plus the counting difference of the time frames of the master gateway station and the master gateway station is multiplied by the preset synchronous period.

3. The method of claim 1, wherein the synchronization control signal with time signaling shares a control channel with the synchronization control signal with control signaling, the synchronization control signal with control signaling is used for each gateway station to transmit a beam switching control command to the satellite, and when the synchronization control signal with time signaling collides with the synchronization control signal with control signaling, the synchronization control signal with control signaling is preferentially transmitted, and the synchronization control signal with time signaling may not be transmitted.

4. The method of claim 1, wherein the synchronization control signal with time signaling and the synchronization control signal with control signaling use the same frame format, and the frame format comprises: the fixed PN sequence and the control information are different from the PN code sequence corresponding to the control signaling and the time signaling.

5. The method of beam hopping synchronization between multiple gateway stations facing high throughput satellite according to claim 1, wherein said preset synchronization period is not higher than 10 ms.

6. The high-throughput satellite communication system adopting the method of claim 1, wherein the high-throughput satellite comprises a network control center, a master gateway station and a plurality of slave gateway stations, the network control center and the plurality of gateway stations have information intercommunication capability to realize beam control coordination among the plurality of gateway stations, and the high-throughput satellite communication system is characterized in that the satellite comprises a control signal analysis module, an on-satellite time reference generation module and a time deviation comparison calculation module;

each gateway station generates a synchronous pulse according to a preset synchronous period according to a self time reference, and sends a synchronous control signal with a synchronous signaling through a control channel at the initial time of the synchronous pulse; the starting time of the synchronous control signal is strictly synchronous with the starting time of the synchronous pulse; the time signaling comprises time frame counting information, and the time frame counting information is a local synchronous pulse counting value corresponding to the starting time of the current synchronous control signal;

the control signal analysis module demodulates and analyzes the synchronous control signals when receiving the synchronous control signals of each gateway station to obtain time frame counting information and recover the synchronous pulses of each gateway station, and the starting edges of the synchronous pulses are aligned with the starting time of the received synchronous control signals;

the satellite time reference generation module generates satellite synchronization pulses and time frame counting information according to the same preset synchronization period according to the own time reference;

the satellite compares the synchronization pulse and the time frame counting information of the satellite with the synchronization pulse and the time frame counting information of the main gateway station according to the synchronization pulse and the time frame counting information of the satellite to obtain the time deviation between the main gateway station and the satellite; comparing the synchronization pulse and the time frame counting information of the slave gateway station with the synchronization pulse and the time frame counting information of the master gateway station to obtain the time deviation between the slave gateway station and the master gateway station; framing the time deviation between each slave gateway station and the master gateway station and the time deviation between the master gateway station and the satellite, and broadcasting to each slave gateway station and the master gateway station through a downlink;

the network control center corrects the time of each gateway station according to the time deviation between each slave gateway station and the master gateway station and the time deviation between the master gateway station and the satellite, so that each slave gateway station is synchronous with the master gateway station, and the master gateway station is synchronous with the time on the satellite.

7. The high throughput satellite communication system according to claim 6, wherein the time offset between the primary gateway station and the satellite is calculated by:

the time difference between the start time of the synchronization pulse on the main gateway station and the satellite plus the counting difference between the main gateway station and the satellite time frame is multiplied by the preset synchronization period.

The specific calculation method of the time deviation between the slave gateway station and the master gateway station comprises the following steps:

the time difference of the starting time of the synchronous pulse of the slave gateway station and the master gateway station plus the counting difference of the time frames of the master gateway station and the master gateway station is multiplied by the preset synchronous period.

8. The high throughput satellite communication system according to claim 6, wherein the synchronization control signal with time signaling shares a control channel with the synchronization control signal with control signaling, the synchronization control signal with control signaling is used for each gateway station to transmit a beam switching control command to the satellite, and when the synchronization control signal with time signaling collides with the synchronization control signal with control signaling, the synchronization control signal with control signaling is preferentially transmitted, and the synchronization control signal with time signaling may not be transmitted.

9. The high throughput satellite communication system according to claim 6, wherein the synchronization control signal with time signaling and the synchronization control signal with control signaling use the same frame format, and the frame format comprises: the fixed PN sequence and the control information are different from the PN code sequence corresponding to the control signaling and the time signaling.

Technical Field

The invention relates to a multi-gateway station beam hopping synchronization method and a multi-gateway station beam hopping synchronization system for a high-throughput satellite, which are mainly used for a beam hopping system based on-satellite transparent forwarding and belong to the technical field of satellite communication.

Background

With the development of internet application, the demand for broadband satellite communication services in the global scope increases year by year, and particularly with the continuous and deep application of technologies such as cloud computing, internet of things, 5G and the like, the characteristic of wide area coverage of satellites gradually emerges, the capacity demand for satellite communication systems will increase in a blowout manner, and the types of information services to be supported will emerge endlessly. To cope with this change in demand, Satellite communication technology is gradually moving toward High Throughput Satellite (HTS) communication systems.

The high-flux satellite is a novel satellite which can provide capacity which is several times to tens times higher than that of a traditional satellite under the same orbit and spectrum conditions through technologies such as spot beam, shaped beam, frequency multiplexing and the like. The typical technical characteristics of this type of system are: the satellite adopts the multi-beam technology to carry out beam overlapping coverage on the service area, thereby realizing the partition on the space dimension while improving the quality of a wireless link; based on the method, the system adopts multiple times of frequency reuse to improve the communication capacity of a single satellite; the gateway stations are closely coupled with the user beam clusters to complete two-hop communication, so that a plurality of gateway stations share communication resources of the same satellite. Spatial isolation of the gateway station is formed, and frequency reuse of the gateway station link is realized again. By using the technology, the total communication capacity of the high-flux satellite communication system is improved by times and tens of times, so that the service cost provided for users is reduced rapidly.

At present, the problem faced in the development of HTS satellite communication systems is mainly focused on two aspects, namely how to further increase the communication capacity of the system to provide more communication resources; and how to improve the flexibility of the system to meet various application scenes and various communication application requirements which may appear. The 2010 European Space Agency (ESA) supports the Bacelona autonomous university to develop related research work in combination with the German Space center, proposes the assumption of the beam hopping technology and theoretically proves the feasibility of improving the system capacity, so far, the beam hopping technology is concerned by the vast relevant research institutions and is determined as the key technology of the new generation of HTS system.

Beam hopping in an HTS system is a special load design mode, a satellite-borne antenna is a full-coverage multi-beam antenna, but repeater resources are shared in a time-sharing manner among a plurality of beams, and essentially, signals hop in a time-sharing manner among different beams according to needs, and a beam hopping system is seen from the user use perspective, and fig. 1 shows a schematic diagram of a typical beam hopping system and a repeater working principle.

The beam hopping system can effectively improve the communication capacity of the HTS system and the flexibility of service application, but the beam hopping system has to be used for achieving the effect of good system-wide beam hopping synchronization, specifically including synchronization between a gateway station forward service signal and satellite beam switching and beam hopping time reference synchronization between a plurality of gateway stations. Figure 2 shows an illustration of the confusion of beam hopping caused by out-of-sync between the gateway station forward traffic signal and satellite beam switching, and figure 3 shows an illustration of the inter-beam interference caused when the hopping beam between multiple gateway stations is out-of-sync.

Foreign relevant documents give a thicker repeater block diagram in the aspect of focusing on the advantages of beam hopping and the improvement analysis of the system capacity, and do not study in detail aiming at a beam hopping synchronization scheme among multiple gateway stations when an HTS system is used.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: overcomes the defects of the prior art, provides a multi-gateway station beam hopping synchronization method and a multi-gateway station beam hopping synchronization system for a high-throughput satellite, and realizes the high-efficiency fusion of beam hopping control and time synchronization with low on-satellite processing complexity

The technical solution of the invention is as follows: a multi-gateway station beam hopping synchronization method facing a high-throughput satellite comprises a network control center, a main gateway station and a plurality of slave gateway stations, wherein the network control center and the plurality of gateway stations have information intercommunication capability to realize beam control coordination among the plurality of gateway stations, and the method comprises the following steps:

s1, each gateway station generates a synchronous pulse according to the self time reference and the preset synchronous period, and sends a synchronous control signal with a synchronous signaling through a control channel at the starting time of the synchronous pulse; the starting time of the synchronous control signal is strictly synchronous with the starting time of the synchronous pulse; the time signaling comprises time frame counting information, and the time frame counting information is a local synchronous pulse counting value corresponding to the starting time of the current synchronous control signal;

s2, when the satellite receives the synchronous control signal of each gateway station, the synchronous control signal is demodulated and analyzed to obtain the time frame counting information, and the synchronous pulse of each gateway station is recovered, and the starting edge of the synchronous pulse is aligned with the starting time of the received synchronous control signal;

s3, the satellite generates satellite synchronization pulses and time frame counting information according to the same preset synchronization period according to the self time reference;

s4, the satellite compares the synchronization pulse and the time frame counting information of the satellite with the synchronization pulse and the time frame counting information of the main gateway station to obtain the time deviation between the main gateway station and the satellite; comparing the synchronization pulse and the time frame counting information of the slave gateway station with the synchronization pulse and the time frame counting information of the master gateway station to obtain the time deviation between the slave gateway station and the master gateway station;

s5, the satellite frames the time deviation between each slave gateway station and the master gateway station and the time deviation between the master gateway station and the satellite, and broadcasts the frames to each slave gateway station and the master gateway station through a downlink;

s6, the network control center corrects the time of each gateway station according to the time deviation between each slave gateway station and the master gateway station and the time deviation between the master gateway station and the satellite, so that each slave gateway station is synchronous with the master gateway station, and the master gateway station is synchronous with the time on the satellite.

Preferably, in step S4:

the specific calculation method of the time deviation between the main gateway station and the satellite comprises the following steps:

the time difference between the start time of the synchronization pulse on the main gateway station and the satellite plus the counting difference between the main gateway station and the satellite time frame is multiplied by the preset synchronization period.

The specific calculation method of the time deviation between the slave gateway station and the master gateway station comprises the following steps:

the time difference of the starting time of the synchronous pulse of the slave gateway station and the master gateway station plus the counting difference of the time frames of the master gateway station and the master gateway station is multiplied by the preset synchronous period.

Preferably, the synchronization control signal with the time signaling and the synchronization control signal with the control signaling share a control channel, the synchronization control signal with the control signaling is used for each gateway station to transmit a beam switching control command to the satellite, and when the synchronization control signal with the time signaling and the synchronization control signal with the control signaling collide, the synchronization control signal with the control signaling is preferentially transmitted, and the synchronization control signal with the time signaling may not be transmitted.

Preferably, the synchronization control signal with time signaling and the synchronization control signal with control signaling use the same frame format, and the frame format includes: the fixed PN sequence and the control information are different from the PN code sequence corresponding to the control signaling and the time signaling.

Preferably, the preset synchronization period is not higher than 10 ms.

The other technical scheme of the invention is as follows: the high-throughput satellite communication system adopting the method is characterized in that the satellite comprises a control signal analysis module, an on-satellite time reference generation module and a time deviation comparison calculation module;

each gateway station generates a synchronous pulse according to a preset synchronous period according to a self time reference, and sends a synchronous control signal with a synchronous signaling through a control channel at the initial time of the synchronous pulse; the starting time of the synchronous control signal is strictly synchronous with the starting time of the synchronous pulse; the time signaling comprises time frame counting information, and the time frame counting information is a local synchronous pulse counting value corresponding to the starting time of the current synchronous control signal;

the control signal analysis module demodulates and analyzes the synchronous control signals when receiving the synchronous control signals of each gateway station to obtain time frame counting information and recover the synchronous pulses of each gateway station, and the starting edges of the synchronous pulses are aligned with the starting time of the received synchronous control signals;

the satellite time reference generation module generates satellite synchronization pulses and time frame counting information according to the same preset synchronization period according to the own time reference;

the satellite compares the synchronization pulse and the time frame counting information of the satellite with the synchronization pulse and the time frame counting information of the main gateway station according to the synchronization pulse and the time frame counting information of the satellite to obtain the time deviation between the main gateway station and the satellite; comparing the synchronization pulse and the time frame counting information of the slave gateway station with the synchronization pulse and the time frame counting information of the master gateway station to obtain the time deviation between the slave gateway station and the master gateway station; framing the time deviation between each slave gateway station and the master gateway station and the time deviation between the master gateway station and the satellite, and broadcasting to each slave gateway station and the master gateway station through a downlink;

the network control center corrects the time of each gateway station according to the time deviation between each slave gateway station and the master gateway station and the time deviation between the master gateway station and the satellite, so that each slave gateway station is synchronous with the master gateway station, and the master gateway station is synchronous with the time on the satellite.

The specific calculation method of the time deviation between the main gateway station and the satellite comprises the following steps:

the time difference between the start time of the synchronization pulse on the main gateway station and the satellite plus the counting difference between the main gateway station and the satellite time frame is multiplied by the preset synchronization period.

The specific calculation method of the time deviation between the slave gateway station and the master gateway station comprises the following steps:

the time difference of the starting time of the synchronous pulse of the slave gateway station and the master gateway station plus the counting difference of the time frames of the master gateway station and the master gateway station is multiplied by the preset synchronous period.

The synchronous control signal with the time signaling and the synchronous control signal with the control signaling share a control channel, the synchronous control signal with the control signaling is used for each gateway station to send a beam switching control instruction to the satellite, and when the synchronous control signal with the time signaling and the synchronous control signal with the control signaling conflict, the synchronous control signal with the control signaling is preferentially sent, and the synchronous control signal with the time signaling can not be sent.

The synchronous control signal with time signaling and the synchronous control signal with control signaling adopt the same frame format, and the frame format comprises: the fixed PN sequence and the control information are different from the PN code sequence corresponding to the control signaling and the time signaling.

Compared with the prior art, the invention has the beneficial effects that:

(1) the invention realizes fast and reliable beam hopping on the satellite and time comparison at the same time through the method that each gateway station sends the beam hopping control signal and the time signaling signal which are associated with the service signal time slot, simplifies the synchronization process of the satellite-to-ground beam hopping and the complexity of on-satellite processing on the premise of not changing a service communication signal system, and realizes the beam hopping synchronization among a plurality of gateway stations.

(2) The beam hopping control signal and the time signaling signal occupy the same carrier bandwidth, the same frame structure design is adopted, and the signals are only distinguished through different leader sequences, the method realizes the on-satellite beam control and time comparison integrated design under the condition of occupying lower extra bandwidth resources, simplifies the on-satellite processing complexity, has small hardware resource overhead of the whole beam hopping synchronous control, can be realized by using antifuse Field Programmable Gate Arrays (FPGA) such as ACTEL and the like, and greatly improves the reliability of on-satellite beam control.

Drawings

FIG. 1 is a block diagram of the components and loading of a typical high throughput satellite beam hopping system;

FIG. 2 is a schematic diagram of signal confusion caused by out-of-sync switching between forward service signals and satellite beams according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of adjacent beam overlapping interference when multiple gateway stations are out of synchronization according to an embodiment of the present invention;

FIG. 4 is a diagram illustrating a multi-gateway station beam hopping synchronization system according to an embodiment of the present invention;

fig. 5 is a signal flow diagram of a multi-gateway station beam hopping synchronization system according to an embodiment of the present invention;

fig. 6 is a schematic diagram illustrating a relationship between a forward control signal and a service signal according to an embodiment of the present invention;

FIG. 7 is a diagram illustrating a beam hopping synchronization control signal according to an embodiment of the present invention;

fig. 8 is a functional block diagram of a satellite-borne beam hopping controller according to an embodiment of the present invention.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and examples.

The invention combines the development requirements of an HTS satellite communication system, provides a multi-gateway station beam hopping synchronization method facing a high-throughput satellite aiming at the requirements of improving the system capacity and service flexibility on beam hopping synchronization, and has the advantages of simple beam hopping synchronization process, quick synchronization time, simple and reliable satellite processing and no dependence on a specific service communication system.

The multi-gateway station beam hopping synchronization method facing the high-throughput satellite comprises a network control center, a master gateway station and a plurality of slave gateway stations, wherein the network control center and the plurality of gateway stations have information intercommunication capability, and the beam control coordination among the plurality of gateway stations is realized, and the method comprises the following steps:

s1, each gateway station generates a synchronous pulse according to the self time reference and the preset synchronous period, and sends a synchronous control signal with a synchronous signaling through a control channel at the starting time of the synchronous pulse; the starting time of the synchronous control signal is strictly synchronous with the starting time of the synchronous pulse; the time signaling comprises time frame counting information, and the time frame counting information is a local synchronous pulse counting value corresponding to the starting time of the current synchronous control signal;

s2, when the satellite receives the synchronous control signal of each gateway station, the synchronous control signal is demodulated and analyzed to obtain the time frame counting information, and the synchronous pulse of each gateway station is recovered, and the starting edge of the synchronous pulse is aligned with the starting time of the received synchronous control signal;

s3, the satellite generates satellite synchronization pulses and time frame counting information according to the same preset synchronization period according to the self time reference;

s4, the satellite compares the synchronization pulse and the time frame counting information of the satellite with the synchronization pulse and the time frame counting information of the main gateway station to obtain the time deviation between the main gateway station and the satellite; comparing the synchronization pulse and the time frame counting information of the slave gateway station with the synchronization pulse and the time frame counting information of the master gateway station to obtain the time deviation between the slave gateway station and the master gateway station;

the specific calculation method of the time deviation between the main gateway station and the satellite comprises the following steps:

the time difference between the start time of the synchronization pulse on the main gateway station and the satellite plus the counting difference between the main gateway station and the satellite time frame is multiplied by the preset synchronization period.

The specific calculation method of the time deviation between the slave gateway station and the master gateway station comprises the following steps:

the time difference of the starting time of the synchronous pulse of the slave gateway station and the master gateway station plus the counting difference of the time frames of the master gateway station and the master gateway station is multiplied by the preset synchronous period.

S5, the satellite frames the time deviation between each slave gateway station and the master gateway station and the time deviation between the master gateway station and the satellite, and broadcasts the frames to each slave gateway station and the master gateway station through a downlink;

s6, the network control center corrects the time of each gateway station according to the time deviation between each slave gateway station and the master gateway station and the time deviation between the master gateway station and the satellite, so that each slave gateway station is synchronous with the master gateway station, and the master gateway station is synchronous with the time on the satellite.

The synchronous control signal with the time signaling and the synchronous control signal with the control signaling share a control channel, the synchronous control signal with the control signaling is used for each gateway station to send a beam switching control instruction to the satellite, and when the synchronous control signal with the time signaling and the synchronous control signal with the control signaling conflict, the synchronous control signal with the control signaling is preferentially sent, and the synchronous control signal with the time signaling can not be sent.

The synchronous control signal with time signaling and the synchronous control signal with control signaling adopt the same frame format, and the frame format comprises: the fixed PN sequence and the control information are different from the PN code sequence corresponding to the control signaling and the time signaling.

The preset synchronization period is not higher than 10 ms.

The high-throughput satellite communication system is characterized in that the satellite comprises a control signal analysis module, an on-satellite time reference generation module and a time deviation comparison calculation module;

each gateway station generates a synchronous pulse according to a preset synchronous period according to a self time reference, and sends a synchronous control signal with a synchronous signaling through a control channel at the initial time of the synchronous pulse; the starting time of the synchronous control signal is strictly synchronous with the starting time of the synchronous pulse; the time signaling comprises time frame counting information, and the time frame counting information is a local synchronous pulse counting value corresponding to the starting time of the current synchronous control signal;

the control signal analysis module demodulates and analyzes the synchronous control signals when receiving the synchronous control signals of each gateway station to obtain time frame counting information and recover the synchronous pulses of each gateway station, and the starting edges of the synchronous pulses are aligned with the starting time of the received synchronous control signals;

the satellite time reference generation module generates satellite synchronization pulses and time frame counting information according to the same preset synchronization period according to the own time reference;

the satellite compares the synchronization pulse and the time frame counting information of the satellite with the synchronization pulse and the time frame counting information of the main gateway station according to the synchronization pulse and the time frame counting information of the satellite to obtain the time deviation between the main gateway station and the satellite; comparing the synchronization pulse and the time frame counting information of the slave gateway station with the synchronization pulse and the time frame counting information of the master gateway station to obtain the time deviation between the slave gateway station and the master gateway station; framing the time deviation between each slave gateway station and the master gateway station and the time deviation between the master gateway station and the satellite, and broadcasting to each slave gateway station and the master gateway station through a downlink;

the network control center corrects the time of each gateway station according to the time deviation between each slave gateway station and the master gateway station and the time deviation between the master gateway station and the satellite, so that each slave gateway station is synchronous with the master gateway station, and the master gateway station is synchronous with the time on the satellite.

The specific calculation method of the time deviation between the main gateway station and the satellite comprises the following steps:

the time difference between the start time of the synchronization pulse on the main gateway station and the satellite plus the counting difference between the main gateway station and the satellite time frame is multiplied by the preset synchronization period.

The specific calculation method of the time deviation between the slave gateway station and the master gateway station comprises the following steps:

the time difference of the starting time of the synchronous pulse of the slave gateway station and the master gateway station plus the counting difference of the time frames of the master gateway station and the master gateway station is multiplied by the preset synchronous period.

The synchronous control signal with the time signaling and the synchronous control signal with the control signaling share a control channel, the synchronous control signal with the control signaling is used for each gateway station to send a beam switching control instruction to the satellite, and when the synchronous control signal with the time signaling and the synchronous control signal with the control signaling conflict, the synchronous control signal with the control signaling is preferentially sent, and the synchronous control signal with the time signaling can not be sent.

The synchronous control signal with time signaling and the synchronous control signal with control signaling adopt the same frame format, and the frame format comprises: the fixed PN sequence and the control information are different from the PN code sequence corresponding to the control signaling and the time signaling.

Example (b):

the ground gateway station group needs to include a network control center, a master gateway station and a plurality of slave gateway stations. The network control center and a plurality of gateway stations have information intercommunication capability. Each gateway station in the system generates a required forward control signaling signal according to the hopping requirement of the service signal, and the forward control signaling signal specifically comprises a control signaling and a time signaling; the signals are sent to the satellite through independent carriers of a feed uplink, a forward link transponder on the satellite receives the signals, then the signals are subjected to carrier separation and then sent to a beam hopping controller, the beam hopping controller detects forward control signaling signals, if the signals are control signaling, beam switching control information contained in the control signaling is extracted and used for switching beams, and if the signals are time signaling, time comparison is carried out, time differences between each slave gateway station and a master gateway station are extracted, and then the time differences are fed back to each slave gateway station.

As shown in fig. 4 and fig. 5, the method for synchronizing hopping beams between multiple gateway stations facing a high throughput satellite according to the present invention includes the following steps:

1) the gateway station group mainly comprises a network control center, a master gateway station and a plurality of slave gateway stations. The network control center and the plurality of gateway stations have information intercommunication capability, and mainly realize beam control coordination among the plurality of gateway stations so as to avoid adjacent beams from distributing service signals simultaneously when the beams are used; the master gateway station is the time reference for the entire system and all slave gateway stations need to be synchronized to the time reference of the master gateway station.

2) And each gateway station generates a service signal and a synchronous control signal according to the beam hopping strategy distributed by the NOCC.

3) And a forward link transponder in the beam hopping satellite load separates a service signal and a control signal sent by each gateway station, wherein the service signal is sent to a power amplification link at the rear end, and a synchronous control signal is sent to a beam hopping controller for processing.

4) And the wave beam hopping controller analyzes and compares time of the synchronous control signals of the plurality of gateway stations, extracts time errors of the slave gateway station and the master gateway station, and controls a switch link at the rear end of the wave beam hopping beam according to the analyzed wave beam hopping control instruction.

The user wave beams controlled by the single gateway station are in one-way open-loop synchronization, the synchronization process is simple, and the synchronization time is short; the time synchronization among the multiple gateway stations is closed-loop synchronization, and the error calculation is completed in the beam hopping controller.

The following focuses on the optimization design of the beam hopping control signal and the on-satellite processing flow of the synchronization control signal.

(1) Beam hopping control signal optimization design

In order to solve the forward synchronization among multiple gateway stations, the invention optimizes the design of a synchronization control signal, wherein the whole control signaling comprises a fixed PN acquisition sequence and control information.

1) The PN sequence with the fixed length is used for the on-satellite control signal burst detection, the requirement of the on-satellite control signal burst detection is good, the selection of the specific PN code length can be determined according to the signal-to-noise ratio of actual control information reaching a beam hopping controller, in order to improve the capturing probability and reduce the false capturing probability, the length of the PN sequence is recommended to be more than 128 bits, the PN sequence can be generated by a common method, the correlation performance of the PN sequence is mainly ensured, and the PN sequence is generated by methods such as a small M sequence, a large M sequence or a Gold code sequence;

2) the control information is recommended to adopt RM (7,64) coding in DVB-S2X standard, and is characterized in that when Es/N0 is 0dB, the error rate is still better than 10E^-9；

3) And the beam hopping synchronous control signal adopts DBPSK, so that a simplified demodulation scheme is conveniently adopted on the satellite.

And by adopting DBPSK modulation and a high-performance RM coding mode, each module in the whole processing flow of the satellite beam hopping control signal is simple to realize.

Since the synchronization requirement among multiple gateway stations is considered, the present invention classifies the synchronization control signal into control signaling and time signaling, as shown in fig. 6, wherein the control signaling and the time signaling use the same frame format, and the difference is that the PN code sequences of the control signaling and the time signaling are different, and the definition of the internal control information is different, as shown in fig. 7.

1) The PN codes of the control signaling and the time signaling are required to have good orthogonality, and the two pieces of control information are ensured not to generate misoperation;

2) and 7-bit effective information in the time signaling is used for transmitting time frame counting information, the specific value is from 0 to 127, the synchronization period can be customized according to the system requirement, and the suggested synchronization period is not less than 10 ms.

3) The control signaling is sent according to the beam hopping requirement, and a control signaling frame is sent in advance according to the requirement when the beam hops; and the time signaling is sent periodically, the sending interval is a resolution interval, the control signaling is sent preferentially when the time signaling conflicts with the control signaling, and the time signaling can be not sent.

(2) Synchronous control signal on-board processing flow

The specific process of time synchronization is as follows:

(1) the main gateway station generates a periodic pulse signal and a frame counting signal according to the time reference of the main gateway station, and sends a synchronous control signal with a time signaling at the initial position of the pulse signal, wherein the rising edge of the first symbol of the synchronous control signal of the time signaling is strictly synchronous with the periodic pulse signal;

(2) the slave gateway station generates a periodic pulse signal and a frame counting signal according to the time reference of the slave gateway station, and sends a time synchronization control signal at the initial position of the pulse signal, wherein the rising edge of the first symbol of the time synchronization control signal is strictly synchronous with the pulse signal;

(3) the satellite generates a periodic pulse signal and a frame counting signal according to the time reference of the satellite;

(4) and the beam hopping controller measures the pulse time difference and the frame counting difference between the pulse signal generated by the satellite and the analyzed main gateway station signal and calculates the time deviation between the satellite and the main gateway station, wherein the specific calculation method is the product of the pulse time difference plus the frame counting difference and the resolution ratio.

With reference to the relationship diagram between the forward service signal and the control signal given in fig. 8, the following diagram provides a processing flow of the satellite-borne beam hopping controller, which specifically includes three parts, namely a control signal analysis module, an on-satellite time reference generation module, and a time deviation comparison calculation module, and the specific processing flow is described as follows:

1) the control signal analysis module is used for respectively capturing and demodulating synchronous control signals of the main gateway station and the plurality of slave gateway stations, and extracting a beam hopping control instruction signal to realize beam control when a control signaling is received; when a time signaling is received, extracting a time synchronization pulse signal and time frame counting information and sending the time synchronization pulse signal and the time frame counting information to a time deviation comparison calculation module for processing;

2) the satellite time reference generation module generates satellite time synchronization pulses according to the interval of time signaling and sends the satellite time synchronization pulses to the time deviation comparison calculation module for processing;

3) the time deviation comparison calculation module mainly has two functions, namely, the time deviation comparison calculation module is used for carrying out comparison calculation with the time pulse of the main gateway station to calculate the time deviation between the main gateway station and the satellite; and comparing the time deviation between each slave gateway station and the master gateway station, wherein the time deviation comprises two parts of frame counting deviation and intra-frame accurate time deviation.

4) The time deviation comparison calculation module also performs framing on the time deviation between each slave gateway station and the master gateway station and the time deviation between the master gateway station and the satellite, and broadcasts the time deviation to the master gateway station and the slave gateway stations through a downlink for time correction between the gateway stations.

In conclusion, the synchronization between the beam hopping and the gateway station service is realized by adopting a fast beam hopping synchronization mode of the satellite synchronous gateway stations based on signaling carrier assistance, and the synchronization among a plurality of gateway stations is realized by a mode of satellite time measurement and comparison calculation; the adopted signaling carrier comprises two signals of a control signaling and a time signaling, the control signaling and the time signaling adopt the same frame format, and the high-efficiency fusion of the beam hopping control and the time synchronization can be realized with lower on-satellite processing complexity through different PN code region classifications.

The invention is not described in detail and is part of the common general knowledge of a person skilled in the art.