CN-116032396-B - System model construction method and system simulation method for low-orbit constellation system

Abstract

The invention provides a system model construction method and a system simulation method for a low-orbit constellation system, and belongs to the field of low-orbit constellation system simulation and efficiency evaluation. According to the construction method, light simulation modeling is carried out on functional entities of a space section, a ground section, an application section and an environment section, the model constructed by the space section comprises a constellation configuration model, a attitude and orbit control subsystem model and a satellite load model, the ground section comprises a main gateway station model and a secondary gateway station model, a large-scale terminal model is constructed by the application section, the environment section comprises a satellite-to-ground microwave channel sub-model and an inter-satellite laser channel sub-model, and model interaction design is carried out to form a satellite-to-ground integrated overall model architecture. The invention ensures the modeling precision of the functional entity, meets the light-weight requirement of simulation modeling, reduces the complexity of system modeling, balances the relationship between the model precision and the light weight, and performs simulation verification and evaluation on the correctness, rationality and effectiveness of the architecture design of the constellation system.

Inventors

• WU ZHIQIANG
• GAO XINYU
• JIA ZHENHUA
• ZHU XIAOHUI
• LI SHAOYANG
• QIAN JINXI
• HAN XIAO
• QIAN ZHIPENG

Assignees

• 中国空间技术研究院

Dates

Publication Date

20260508

Application Date

20221107

Claims (9)

1. 1. The system model construction method for the low-orbit constellation system is characterized by comprising the following steps of: Dividing a low-orbit constellation system into a space section, a ground section, an application section and an environment section; The space segment is modeled in a lightweight mode, and the model constructed by the space segment comprises a constellation configuration model, an orbit control subsystem model and a satellite load model, wherein when the simulation is carried out, the constellation configuration model generates constellation topological relation and orbit attitude initial values according to constellation configuration design and respectively sends the constellation topological relation and the orbit attitude initial values to the satellite load model and the orbit control subsystem model; The method comprises the steps of carrying out light modeling on a ground section, wherein a model constructed by the ground section comprises a main gateway station model and a secondary gateway station model, and simultaneously realizing an access network function by the main gateway station model and the secondary gateway station model when carrying out simulation, and a core network function by the main gateway station model, wherein the access network realizes a feed link signal receiving and transmitting function, and a terminal access registration and authentication function by the core network; the application segment model is used for completing the functions of beam selection, visibility analysis, service data generation, data receiving and transmitting and signaling processing when simulation is carried out; The method comprises the steps of carrying out light modeling on an environment section, wherein a model constructed by the environment section comprises a satellite-ground microwave channel sub-model and an inter-satellite laser channel sub-model, and when the modeling is carried out, the satellite-ground channel sub-model considers free space loss, doppler effect, noise, atmosphere, rain, snow and cloud loss and the inter-satellite channel sub-model considers the influence of the solar energy on a laser link; The method comprises the steps of carrying out model interaction design on a space segment, a ground segment, an application segment and an environment segment when the space segment, the ground segment, the application segment and the environment segment are subjected to light modeling, wherein a constellation configuration model, a large-scale terminal model and a main/auxiliary gateway station model respectively interact service information and signaling information with a satellite-to-ground microwave channel sub-model and an inter-satellite laser channel sub-model in a data middleware mode, in the process of the instantiation, the satellite-to-ground microwave channel sub-model and the inter-satellite laser channel sub-model respectively instantiate only 1, data of all constellation configuration models, terminal models and main/auxiliary gateway station models are concentrated in 1 channel model to interact, information repeated transmission is carried out by the constellation configuration models and the large-scale terminal models in a pairwise crossing mode, the service information and the signaling information are forwarded through receiving and transmitting antenna models of various entities, and the transmission is carried out by adopting unified simplified IP data packets, so that complex interface simplification processing among models is realized, and data interaction among models is easy.
2. 2. The system model construction method for the low orbit constellation system according to claim 1, wherein the inter-satellite topological relation generated by the constellation configuration model is described by adopting a two-dimensional table, wherein '1' represents inter-satellite connection and '0' represents inter-satellite connection, the constellation configuration model calculates an orbit six-element initial value and an attitude parameter initial value of each satellite in a constellation according to constellation configuration parameters, and data uploading is carried out.
3. 3. The method for constructing a system model for a low orbit constellation system according to claim 1, wherein the attitude and orbit control subsystem model comprises an attitude dynamics sub-model, an orbit dynamics sub-model and an on-board guidance, navigation and control GNC control sub-model, The orbit dynamics sub-model consists of an ideal orbit model and a HPOP high-precision orbit model, wherein the ideal orbit model does not consider the influence of other external interference forces, and the HPOP high-precision orbit model considers a thruster control force model, an earth non-spherical perturbation power model, an atmosphere resistance perturbation power model, a solar-lunar attraction perturbation power model and a solar light pressure perturbation power model; the attitude dynamics sub-model consists of an internal control moment model and an external disturbance model, wherein the internal control moment model takes a flywheel model, a magnetic torquer model and a thruster model into consideration, and the external disturbance model takes a gravity gradient moment model, a solar radiation moment model, a aerodynamic moment model and a geomagnetic moment model into consideration; The on-board GNC control sub-model completes satellite attitude control, pointing control and orbit control key parameter calculation according to the orbit and attitude data input of the orbit dynamics sub-model and the attitude dynamics sub-model, feeds back the calculated control force to the orbit dynamics sub-model to carry out satellite orbit adjustment, and feeds back the control moment to the attitude dynamics sub-model to carry out satellite attitude adjustment.
4. 4. The method of architecture model construction for low orbit constellation system according to claim 1, wherein the satellite load model comprises a narrowband mobile communication load, a wideband integrated communication load, an aviation monitoring load, a feeding load, a laser inter-satellite link load, a load integrated processor and a beacon load sub-model, wherein, The narrowband mobile communication payload includes: the multi-beam receiving antenna model is used for completing wireless signal reception and has the functions of beam coverage, frequency division multiplexing, beam closing and power and frequency resource allocation; The multi-beam transmitting antenna model is used for completing wireless signal transmission and has the functions of beam coverage, frequency division multiplexing, beam closing and power and frequency resource allocation; The receiver model is used for completing link budget analysis, matching information rate, frequency, bandwidth, modulation mode and coding mode, and realizing bit error rate calculation; The transmitter model is used for adding the information rate, the frequency, the bandwidth, the modulation mode and the coding mode to the signaling data packet for transmission; the resource allocation model is used for realizing the functions of primary allocation and reallocation of resources, including beam, power, bandwidth, frequency and time slot allocation; The signaling processing model is used for completing network access authentication, switching, network utilization and network exit signaling processing; the broadband integrated communication payload includes: The phased array receiving antenna model is used for completing wireless signal reception and has the functions of beam coverage, wave position switching and beam staring; The phased array transmitting antenna model is used for completing wireless signal transmission and has the functions of beam coverage, wave position switching and beam staring; The receiver model is used for completing link budget analysis, matching information rate, frequency, bandwidth, modulation mode and coding mode, and realizing bit error rate calculation; The transmitter model is used for adding the information rate, the frequency, the bandwidth, the modulation mode and the coding mode to the signaling data packet for transmission; the resource allocation model is used for realizing the functions of primary allocation and reallocation of resources, including beam, power, bandwidth, frequency and time slot allocation; the signaling processing model is used for completing the functions of network access authentication, switching, network utilization and network quit signaling processing on the satellite; the aviation monitoring load includes: the multi-beam receiving antenna model is used for completing wireless signal reception and has the functions of beam coverage, frequency division multiplexing, beam closing and power and frequency resource allocation; The receiver model is used for completing message conflict detection and link budget analysis, and matching information rate, frequency, bandwidth, modulation mode and coding mode to realize bit error rate calculation; The feed load includes: The mechanical movable receiving antenna model is used for completing wireless signal receiving and has the functions of beam coverage and mechanical rotation; The mechanical movable transmitting antenna model is used for completing wireless signal transmission and has the functions of beam coverage and mechanical rotation; the feed receiver model is used for completing link budget analysis, matching information rate, frequency, bandwidth, modulation mode and coding mode, and realizing bit error rate calculation; The feed transmitter model is used for adding the information rate, the frequency, the bandwidth, the modulation mode and the coding mode to the signaling data packet for transmission; the resource allocation model is used for realizing the functions of primary allocation and reallocation of resources, including beam, power, bandwidth, frequency and time slot allocation; The signaling processing model is used for completing the network access authentication, switching, network utilization and network withdrawal signaling processing functions of the gateway station; The laser inter-satellite link load includes: The laser terminal pointing model is used for calculating the laser terminal pointing based on ephemeris data; The laser terminal receives the telescope model, is used for receiving the light wave signal, and adjust and receive the telescope to point according to the goal to point data; the laser terminal transmits a telescope model, is used for transmitting light wave signals and adjusting the pointing direction of the transmitting telescope according to target pointing data; The laser terminal receiver model is used for completing laser link budget analysis, matching information rate, bandwidth, modulation mode and coding mode, and realizing bit error rate calculation; the laser terminal transmitter model is used for adding the information rate, the frequency, the bandwidth, the modulation mode and the coding mode to the signaling data packet for transmission; The resource allocation model is used for allocating bandwidth resources for the multi-type business data; The load comprehensive processor is used for completing the route switching function of each path of load data, and comprises the following components: the link congestion model is used for setting the occupation proportion of satellite node resources and informing the route calculation model of the resource load condition; The link fault model is used for setting satellite node faults and informing the route calculation model of resource load conditions; The service priority processing model is used for carrying out routing priority sorting according to the user grade and placing the data packets into a routing data buffer area according to the priority; The route calculation model is used for having the functions of route calculation, route table generation and route update based on the shortest path algorithm; the routing addressing model is used for carrying out routing addressing on the data packet in the buffer area to obtain a next-hop address; and the data distribution model is used for completing distribution processing of the data packet to each port according to the routing address.
5. 5. The architecture model construction method for a low-orbit constellation system according to claim 1, wherein the main gateway station model includes an access network sub-model and a core network sub-model, and wherein the access network sub-model includes: the receiving antenna model is used for completing the receiving of the wireless signals of the feed link and has the functions of beam coverage and mechanical rotation; The transmitting antenna model is used for completing the wireless signal transmission of a feed link and has the functions of beam coverage and mechanical rotation; the receiver model is used for completing the link budget analysis of the service and the signaling, matching the information rate, the frequency, the bandwidth, the modulation mode and the coding mode, and realizing the calculation of the signal-to-noise ratio and the bit error rate; The transmitter model is used for adding the information rate, frequency, bandwidth, modulation mode and coding mode to the service and signaling data packet for transmission; the signaling processing model is used for completing the simplified protocol stack processing functions including initial network access, random access, reconstruction, reselection, registration and switching functions; The packet grouping model is used for grouping and ordering the service data according to the IP packet simplification mode and distributing dynamic IP addresses to the source entity and the target entity; the unpacking model is used for realizing the reordering of the packets according to the IP packet simplification mode and extracting service data from the packets; The cross-constellation service data forwarding model is used for extracting service data of the feed link and forwarding the service data to the core network for switching; The core network sub-model comprises: The network access authentication model is used for completing user identity identification, network access registration and dynamically distributing IP addresses for users; and the data exchange model is used for completing the inter-constellation service data exchange forwarding.
6. 6. The architecture model construction method for a low-orbit constellation system according to claim 1, wherein the large-scale terminal model constructed by the application segment comprises: the beam selection model is used for calculating the distance from the user to the beam center according to the fact that the user points at the satellite beam center, and selecting the beam with the shortest distance as an access beam; the user receiving antenna model is used for completing wireless signal receiving; The user transmitting antenna model is used for completing wireless signal transmission; the receiver model is used for completing the link budget analysis of the service and the signaling, matching the information rate, the frequency, the bandwidth, the modulation mode and the coding mode, and realizing the calculation of the signal-to-noise ratio and the bit error rate; The transmitter model is used for adding the information rate, frequency, bandwidth, modulation mode and coding mode to the service and signaling data packet for transmission; the signaling processing model is used for completing the simplified protocol stack processing functions including initial network access, random access, reconstruction, reselection, registration and switching functions; The packet grouping model is used for grouping and ordering the service data according to the IP packet simplification mode and distributing dynamic IP addresses to the source entity and the target entity; the unpacking model is used for realizing the reordering of the packets according to the IP packet simplification mode and extracting service data from the packets; the business model is used for generating business data types, and business features are marked by text labels; The moving model is used for linear movement, annular movement, random movement and opposite movement; The position distribution characteristic model is used for uniformly distributing the positions in the whole world, randomly distributing the positions in the whole world and distributing the positions according to the population density of the whole world; The call characteristic model is used for statistically obeying Poisson distribution of user call arrival time and statistically obeying exponential distribution of user call service time.
7. 7. The method for constructing a system model for a low-orbit constellation according to claim 1, wherein the satellite-to-ground microwave channel sub-model comprises: The free space loss submodel is used for calculating the air attenuation according to the frequency and the distance; A Doppler effect sub-model for calculating Doppler frequency shift and first order Doppler change rate according to the relative motion; The noise model submodel is used for calculating noise power according to a noise theoretical formula; The rainfall loss submodel is used for calculating rainfall loss according to an ITU-R rainfall attenuation empirical formula; The atmosphere loss submodel is used for calculating the atmosphere loss according to an ITU-R atmosphere attenuation empirical formula; the cloud and fog loss submodel is used for calculating the atmospheric loss according to an ITU-R cloud and fog attenuation empirical formula; The snowfall loss submodel is used for calculating the atmospheric loss according to an ITU-R snowfall attenuation empirical formula; The inter-satellite laser channel submodel comprises: and the solar noise model submodel is used for calculating an included angle according to the position relation of the sun, the satellite and the earth station, judging a threshold value, and considering communication interruption if the included angle is smaller than the threshold value.
8. 8. A system simulation method for a low-orbit constellation system, which is characterized by comprising the following steps based on a system model constructed by the method according to any one of claims 1-7: Step S201, inputting orbit parameters and initial values of the attitude parameters into a satellite attitude orbit control subsystem model by a constellation configuration model, generating real-time orbit data and attitude data by the attitude orbit control subsystem model, and transmitting the real-time orbit data and the attitude data to other models; step S202, after a satellite load terminal load comprehensive processor obtains constellation topological relation and orbit position information of each satellite, calculating the shortest distance from the satellite to other satellites by adopting a shortest path algorithm, and generating a routing table; step S203, the satellite load model receiving and transmitting antenna calculates the antenna orientation through orbit data and attitude data, and broadcasts satellite position and antenna orientation information through transmitting antenna signaling beams, all the information is attached to a simplified IP data packet, a destination address in the data packet is set as a broadcast address, and the destination address represents that all ground entities can receive the information and download the information through a satellite-to-ground link; Step S204, after receiving the broadcast data packet, the terminal calculates the visibility, namely calculates the elevation angle from the terminal to the satellite, judges whether the elevation angle constraint condition is reached, judges that the satellite can build a chain, carries out the next processing, and otherwise judges that the satellite can not build a chain; step S205, carrying out beam selection processing under the condition that a satellite is visible, firstly calculating the distance between a terminal and a satellite beam center pointing point, selecting a satellite beam corresponding to the shortest distance as a selection result, setting a beam residence threshold, namely, if the distance is within a certain range, the terminal always selects the beam, and when the distance exceeds the threshold, reselecting an access beam according to the same method; Step S206, the terminal sends a network-access registration request through a transmitting antenna, the information is attached to a simplified IP data packet, and the destination address is set as the address of a main gateway station; Step S207, the satellite load comprehensive processor performs route exchange processing according to the address information of the network access registration request data packet, and forwards the data packet through an inter-satellite link; step S208, the core network of the main gateway station receives the data packet, performs authentication, distributes an IP address for the terminal, completes the registration request, and replies the confirmation information of the registration request; Step S209, after receiving the registration request confirmation information, the terminal applies for network usage, attaches the beam access information, the service type, the bandwidth rate and the called information to an IP packet, and sends the IP packet to a satellite network through a signaling beam; step S210, after receiving the network request, the satellite accessed by the calling terminal allocates resources for the satellite and sends confirmation information to the calling; step S211, after receiving the paging information, the called terminal initiates a network request to the accessed satellite, the satellite allocates resources and sends confirmation information; Step S212, when the allocation of the resources of the calling party and the called party is successful, the link establishment is successful, and both communication parties can perform service interaction; Step S213, if the link establishment is successful, the service information of the calling party and the called party is transmitted by adopting a simplified IP packet, the data receiving and transmitting are realized through the accessed microwave satellite-to-ground link, and the route exchange and the data forwarding are realized through the inter-satellite laser link; step S214, the transmission of signaling and service information passes through a channel model, the channel model obtains the position, speed, power and frequency information of a receiving end and a transmitting end, and the position, speed, power and frequency information are transmitted to the receiving end after power attenuation, doppler frequency offset, noise power and propagation delay calculation are completed; Step S215, the receiving antenna of each entity calculates the visibility according to the position information of the receiving and transmitting end, if so, frequency matching is carried out, if the Doppler offset is within the receiving bandwidth, the data packet is transmitted to the receiving antenna for the next processing; Step S216, the receiver calculates the power attenuation value in the extracted information packet to complete the link, obtain the signal to noise ratio, and obtain the error rate of the receiver by inquiring the error curve table; Step S217, for satellite nodes, if the error rate is higher than the threshold value, discarding the data packet, and not forwarding the next node, otherwise, inputting the data packet into a load comprehensive processor for route exchange, and completing data forwarding until the data is transmitted to a target node; Step S218, in the network using process, the calling and called users continuously send the beam selection result to the accessed satellite for switching judgment, when switching is needed, the source satellite sends a switching request to the target satellite, and the target satellite inquires whether the resources are available after receiving the request; Step S219, if the target satellite resources are available, the target satellite performs resource allocation and notifies the source satellite to forward the result to the user, and the user switches to the target satellite after receiving the information; Step S220, when the user communication is finished, initiating a broken link request, and releasing resources after the accessed satellite receives the request, so as to complete the network using process; Step S221, when the user quits the network, a network quit request is initiated and forwarded to the gateway station core network through the inter-satellite network, and the core network model carries out deregistration processing on the user information to complete the network quit flow.
9. 9. The architectural simulation method according to claim 8, wherein the simulation method further comprises: step S222, evaluating the simulation effect by adopting an index evaluation method, wherein the evaluation comprises system error rate evaluation, system packet loss rate evaluation, system interruption rate evaluation and system capacity evaluation.

Description

System model construction method and system simulation method for low-orbit constellation system Technical Field The invention belongs to the field of low-orbit constellation system simulation and efficiency evaluation, and particularly relates to a system model construction method and a system simulation method for a low-orbit constellation system. Background In the satellite communication field, low orbit constellation systems can provide much higher communication capacity, much lower communication latency than conventional communication satellites. The low-orbit constellation system consists of a near-polar orbit satellite, an inclined orbit satellite and a ground support system, is fused with a ground 5G system, has the characteristics of high integration level, high performance, high complexity and the like, and is mostly in a planning stage at present. The huge scale and technical complexity of the low-orbit constellation system bring a plurality of unexpected problems to various aspects such as planning demonstration, system development, on-orbit management and the like. Disclosure of Invention In view of the above-mentioned drawbacks or shortcomings in the prior art, the present invention aims to provide a system model construction method and a system simulation method for a low-orbit constellation system, which are based on distributed simulation to respectively implement lightweight model design on a space segment, a ground segment, an application segment and an environment segment of the low-orbit constellation system, evaluate inter-satellite laser alignment, system operation efficiency and communication evaluation indexes, implement complex interactive process simulation verification of a satellite-ground interface, and improve simulation accuracy and reliability. In order to achieve the above purpose, the embodiment of the present invention adopts the following technical scheme: in a first aspect, an embodiment of the present invention provides a system model construction method for a low-orbit constellation system, where the system model construction method includes: Dividing a low-orbit constellation system into a space section, a ground section, an application section and an environment section; The space segment is modeled in a lightweight mode, and the model constructed by the space segment comprises a constellation configuration model, an orbit control subsystem model and a satellite load model, wherein when the simulation is carried out, the constellation configuration model generates constellation topological relation and orbit attitude initial values according to constellation configuration design and respectively sends the constellation topological relation and the orbit attitude initial values to the satellite load model and the orbit control subsystem model; The method comprises the steps of carrying out light modeling on a ground section, wherein a model constructed by the ground section comprises a main gateway station model and a secondary gateway station model, and simultaneously realizing an access network function by the main gateway station model and the secondary gateway station model when carrying out simulation, and a core network function by the main gateway station model, wherein the access network realizes a feed link signal receiving and transmitting function, and a terminal access registration and authentication function by the core network; the application segment model is used for completing the functions of beam selection, visibility analysis, service data generation, data receiving and transmitting and signaling processing when simulation is carried out; The environment section is modeled in a lightweight mode, the model constructed by the environment section comprises a satellite-ground microwave channel sub-model and an inter-satellite laser channel sub-model, and when simulation is carried out, the satellite-ground channel sub-model considers free space loss, doppler effect, noise, atmosphere, rain, snow and cloud loss, and the inter-satellite channel sub-model considers the influence of the solar on a laser link. In the process of instantiation, the satellite microwave channel sub-model and the inter-satellite laser channel sub-model are only respectively instantiated for 1, the data of all the constellation configuration model, the terminal model and the main/auxiliary gateway station model are concentrated in 1 channel model for interaction, the information repeated transmission is carried out by pairwise intersection of the constellation configuration model and the large-scale terminal model, the service information and the signaling information are transmitted by receiving and transmitting antenna models of various entities, and the transmission is carried out by adopting unified simplified IP data packets, so that the complex interface between the models is simplified, and the data interaction between the models is easy. As a preferred embodiment of the