Satellite communication simulation system and control method thereof

Abstract

This invention discloses a satellite communication simulation system and its control method, belonging to the field of satellite communication simulation technology. The system includes an interface control and data management module, a satellite network control center simulation module, a communication satellite simulation module, a ground satellite service access station simulation module, and an airborne satellite communication terminal simulation module. These modules respectively realize full-process training scheduling, full-process network control simulation, on-board transparent forwarding simulation, multi-type ground station full-level simulation, and airborne terminal communication simulation. The system can be expanded to interface with external channel and environment simulation equipment and external evaluation systems, covering the entire satellite communication training process. This system balances the realism of training scenarios with configuration flexibility, reducing the training cost of real equipment. It covers multiple training scenarios from single-unit operation to comprehensive drills, supports three-dimensional quantitative training effect evaluation, can be integrated into comprehensive training environments, and effectively improves the efficiency of satellite communication operation training.

Description

Technical Field

[0001] This invention relates to the field of satellite communication simulation technology, and in particular to a satellite communication simulation system and its control method. Background Technology

[0002] Satellite communication, as a core component of the integrated air-space-ground communication network, is widely used in scenarios such as command communication, emergency communication, and remote transmission. Personnel in related positions need to be proficient in multiple skills such as equipment operation, network establishment, handling abnormal situations, and troubleshooting in order to meet the communication networking needs in complex scenarios.

[0003] Traditional satellite communication training often relies on real-world equipment. On one hand, the procurement and maintenance costs of real-world equipment are high, frequent training can easily lead to equipment wear and tear, and the training process requires real spectrum resources. It is also limited by factors such as location, airspace, and electromagnetic environment, making large-scale, multi-batch training difficult, especially for cross-domain networking training on airborne and shipborne mobile platforms, where the implementation difficulty and safety risks are high. On the other hand, real-world training struggles to reproduce various extreme environments, equipment failures, electromagnetic interference, and other special scenarios, making it difficult to fully train trainees' ability to handle abnormal situations, and significantly limiting the scope of training scenarios.

[0004] Existing satellite communication simulation systems mostly adopt pure software simulation or single hardware simulation architectures. The interoperability between the two types of simulation is insufficient, making it difficult to simultaneously meet the requirements of operational realism and flexible scenario configuration. Pure software simulation systems cannot reproduce the transmission characteristics of real radio frequency links and the hardware operation logic of equipment, resulting in discrepancies between training effects and actual scenarios. On the other hand, single hardware simulation systems lack flexibility, making it difficult to quickly configure various training scenarios and unable to support large-scale virtual site networking simulations.

[0005] Meanwhile, most existing simulation systems lack external connectivity, are unable to achieve standardized data interaction with external channel environment simulation equipment and external evaluation systems, and are difficult to integrate into a systematic joint training environment. Furthermore, their training and evaluation functions are relatively simple, often only able to make simple judgments on the final communication results, and are unable to make comprehensive quantitative evaluations of multi-dimensional capabilities such as operational standardization, network timeliness, and reasonable handling of abnormal situations, making it difficult to meet the current full-process, full-element satellite communication training needs. Summary of the Invention

[0006] This invention proposes a satellite communication simulation system and its control method to solve the problems existing in the prior art. The technical solution is as follows: In a first aspect, embodiments of this application provide a satellite communication simulation system, including an interface control and data management module, a satellite network control center simulation module, a communication satellite simulation module, a ground satellite service access station simulation module, and an airborne satellite communication terminal simulation module. The interface control and data management module is used to construct training mission scenarios and generate communication network schemes, issue guidance and control commands, and collect operational status data from each simulation module. It communicates with each simulation module through a unified data interface, supporting centralized scheduling for mission planning, network training, abnormal situation handling, and performance evaluation. Its functional sub-modules are synchronized in real time through a shared data pool. The satellite network control center simulation module is used to simulate network management and station control functions, generating network control parameters for the FDMA and TDMA integrated service networks based on the communication network scheme and issuing them to the ground satellite service access station simulation module and the airborne satellite communication terminal simulation module. It supports communication subnet configuration and channel... The system includes simulations of resource allocation, network entry / exit signaling interaction, and parallel management of multiple communication subnets. A communication satellite simulation module simulates transparent forwarding functionality, receiving uplink RF or digital analog signals, amplifying them with low noise, downconverting, filtering with intermediate frequency, and upconverting them to generate downlink signals for output. It supports Ku and UHF band forwarding simulation and dynamic updates of channel environment parameters. A ground satellite service access station simulation module simulates stationary satellite communication vehicle-mounted stations, box-type stations, and mobile satellite communication vehicle-mounted stations. It achieves full-level simulation coverage through RF, hardware-in-the-loop, and digital operation simulators. Its uplink signal output is sent to the communication satellite simulation module, while the downlink signal originates from the communication satellite simulation module. An airborne satellite communication terminal simulation module simulates airborne platform Ku and UHF band satellite communication terminal equipment, supporting simulations of voice communication and short message data transmission between the airborne terminal and the ground satellite service access station simulation module via the communication satellite simulation module.

[0007] Furthermore, the communication satellite simulation module dynamically updates channel environment parameters through the channel environment simulation unit. The channel environment simulation unit establishes a unified radio frequency signal interface and network data interface with the external channel and environment simulation equipment, and receives channel environment parameters injected by the external channel and environment simulation equipment. The channel environment parameters include multipath fading model parameters, rain attenuation parameters, Doppler frequency shift parameters, and co-channel interference signal parameters. The communication satellite simulation module determines the transmission impairment in the radio frequency domain and the transmission impairment in the baseband domain according to the channel environment parameters, applies the transmission impairment in the radio frequency domain to the radio frequency simulation link, and applies the transmission impairment in the baseband domain to the digital simulation link, so that the transmission impairment of the radio frequency simulation link and the digital simulation link are updated synchronously.

[0008] Furthermore, the interface control and data management module also includes a training and evaluation docking unit. The training and evaluation docking unit establishes a standardized data exchange interface with the external evaluation system and receives task plan files, command and control instructions, and task role configuration information through the data exchange interface. The training and evaluation docking unit reads the communication link operation data, channel resource usage data, and operation status data of each simulation module from the shared data pool, generates performance evaluation indicators based on the read data, reports the performance evaluation indicators to the external evaluation system through the data exchange interface, and writes the performance evaluation indicators into the shared data pool for synchronous use by each functional submodule.

[0009] Furthermore, the networking training submodule of the interface control and data management module adopts a scenario-driven training organization method. Based on the pre-stored communication networking scenario file, it automatically generates communication subnet parameter configuration, channel resource allocation scheme, and ground satellite service access station network access sequence. The networking training submodule distributes the generated configuration parameters to the satellite network control center simulation module, the ground satellite service access station simulation module, and the airborne satellite communication terminal simulation module through a unified data interface. After receiving the configuration parameters, each simulation module completes the device initialization process and the network link establishment process. After the network link establishment is completed, the interface control and data management module obtains the operating status data and link quality indicators of each simulation module through a polling acquisition mechanism, evaluates the networking effect based on preset scoring rules, and displays the evaluation results in the form of radar charts and quantitative scoring tables.

[0010] Furthermore, the satellite network control center simulation module generates network control parameters for the FDMA integrated service network and the TDMA integrated service network using a parametric simulation configuration method, and pre-establishes a satellite transponder parameter library, a beam coverage model library, and a channel template library. During simulation operation, the satellite network control center simulation module automatically matches the corresponding transponder parameters, beam coverage range, and channel template parameters from the satellite transponder parameter library, beam coverage model library, and channel template library according to the communication networking scheme provided by the task planning submodule of the interface control and data management module. Based on the matching results, the satellite network control center simulation module calculates the uplink effective omnidirectional radiated power of each ground satellite service access station using the following formula. : ; in, The uplink effective omnidirectional radiated power of the ground satellite service access station; Antenna transmit gain; This refers to the feeder insertion loss; The transmitter output power is expressed in decibels.

[0011] Furthermore, the Ku-band forwarding RF simulator of the communication satellite simulation module adopts a single-conversion architecture to achieve transparent forwarding processing of uplink RF signals to downlink RF signals. The Ku-band forwarding RF simulator amplifies the received uplink Ku-band RF signal sequentially through a low-noise amplifier, downconverts it to an intermediate frequency signal, filters the intermediate frequency, adjusts it with automatic gain control, and upconverts it to a downlink Ku-band RF signal before amplifying it with a power amplifier and outputting it. The local oscillator signals of the upconverter and downconverter are provided by a common local oscillator phase-locked loop frequency synthesizer. The overall gain and noise figure of the Ku-band forwarding RF simulator are calibrated according to the model parameters of the communication satellite being simulated.

[0012] Furthermore, the RF simulator of the ground satellite service access station simulation module adopts a plug-in modular design, dividing the channel terminal RF simulator, frequency converter RF simulator, and splitter / combiner RF simulator of different frequency bands into independent standard plug-in modules according to their functional types; each plug-in module has a standardized intermediate frequency interface and low frequency monitoring interface on its back panel. Each plug-in module transmits intermediate frequency signals through the intermediate frequency interface on the unified back panel bus and exchanges operating status data through the low frequency monitoring interface; each plug-in module has status indicator lights and RF test interfaces on its front panel, and transmits RF signals and network data bidirectionally with external devices through RF cables and Ethernet cables.

[0013] Secondly, embodiments of this application provide a control method for a satellite communication simulation system, applied to the aforementioned satellite communication simulation system, comprising: S1, the interface control and data management module loads the preset training task scenario file, parses the list of training stations, communication networking scheme and performance evaluation parameters in the training task scenario file, generates training task instances and assigns a unique training task number. S2. The satellite network control center simulation module configures network control parameters for the ground satellite service access station simulation module and the airborne satellite communication terminal simulation module according to the network topology in the communication networking scheme. The network control parameters include communication subnet identifier, transponder frequency resources, control channel parameters and channel unit address. The network control parameters are then sent to the corresponding ground satellite service access station simulation module and airborne satellite communication terminal simulation module through a unified data interface. S3. After receiving the network control parameters, the ground satellite service access station simulation module and the airborne satellite communication terminal simulation module automatically execute the equipment initialization process. According to the FDMA or TDMA network access protocol corresponding to the configured network control parameters, they initiate a network access request to the satellite network control center simulation module. The satellite network control center simulation module performs access authentication based on the channel unit address and user number in the network access request. After successful authentication, a communication link is established and a network access confirmation message is sent back. S4. During network communication, the interface control and data management module injects fault parameters or channel environment parameters into the designated simulation module according to the preset abnormal situation handling plan or guidance control command, simulates equipment failure or channel degradation scenarios, and records the handling operation sequence and operation time input by the user through each simulation module. S5. After training, the interface control and data management module collects operation logs and running status data throughout the process. According to the corresponding scoring rules and weights in the performance evaluation parameters, it performs quantitative scoring from three evaluation dimensions: operation standardization, network timeliness, and fault handling capability, and generates a training evaluation report.

[0014] Furthermore, the access authentication process of the FDMA network access protocol in step S3 includes: The ground satellite service access station simulation module sends a network access request message in a contention-based manner on the control ALOHA channel configured in the network control parameters. The network access request message includes the channel unit address of the ground satellite service access station simulation module, the user number, and the type of service requested. After receiving the network access request message, the satellite network control center simulation module queries the preset authentication table to verify the legality of the channel unit address and user number; After successful verification, the satellite network control center simulation module sends a network access confirmation response to the ground satellite service access station simulation module on the TDM broadcast channel and marks the channel unit status of the ground satellite service access station simulation module as online; if the verification fails, the satellite network control center simulation module sends a network access rejection response message on the TDM broadcast channel, which includes the corresponding rejection reason code.

[0015] Furthermore, in step S5, the operational standardization score is calculated based on the consistency rate and sequence correctness between the actual operation steps of the operator and the standard operation procedure template; the network formation timeliness score is calculated based on the ratio of the total time from the issuance of the network formation command to the completion of network access for all participating stations to the preset standard time in the performance evaluation parameters; the fault handling capability score is calculated based on the comprehensive calculation of the operator's fault location time and the correctness of the handling plan; the three evaluation dimensions are weighted and averaged according to the weights in the performance evaluation parameters to obtain the operator's final evaluation result.

[0016] Compared with existing technologies, the beneficial effects of this invention are: This system adopts an architecture design that achieves full-level simulation coverage using radio frequency operation simulators, hardware-in-the-loop (HIL) simulators, and digital operation simulators. Without requiring full configuration of real equipment, it can not only reproduce the transmission characteristics and signal processing flow of real satellite communication radio frequency links, but also reproduce the hardware operation logic and service interaction flow of various types of equipment. While controlling training costs, it improves the realism of training scenarios and can meet the multi-level training needs of different levels of operators, from basic equipment operation to complex network drills.

[0017] The system adopts a unified interface control and data management module to realize centralized scheduling of each simulation module. The internal modules realize real-time synchronization of training data through a shared data pool, avoiding data conflicts and inconsistent states between multiple systems. The system is equipped with standardized interface interfaces to achieve data interaction with external evaluation systems and external channel and environment simulation equipment. It can be integrated into the comprehensive training environment and support comprehensive training tasks with multi-module collaboration.

[0018] The system supports flexible configuration of multiple training scenarios and can build a full range of training subjects as needed, from single-device operation training and network link establishment training to abnormal situation handling training and comprehensive drills. It can simulate various abnormal scenarios such as channel environment changes, equipment failures, co-channel interference, and site failures, filling the scenario coverage blind spots of traditional real equipment training and helping to comprehensively improve the communication networking and fault handling capabilities of operators.

[0019] The system has built-in functions for full-process training data acquisition and three-dimensional quantitative evaluation. It can automatically record operation logs, device status, and business transmission data throughout the training process. Based on preset rules, it completes quantitative evaluation of training effectiveness from three dimensions: operational standardization, network timeliness, and fault handling capability. It can intuitively present the shortcomings of the operator's capabilities and assist in targeted improvement of training effectiveness.

[0020] The system adopts a modular and highly scalable architecture design. It can be expanded to include new station simulation modules and new communication system simulation functions according to new training needs without making major adjustments to the overall architecture, resulting in low iteration and upgrade costs. At the same time, it supports parallel management and control of multiple communication subnets and parallel execution of multiple training tasks, improving the utilization rate of training resources and meeting the synchronous training needs of multiple batches and different subjects. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the architecture of the satellite communication simulation system proposed in this invention; Figure 2 This is a flowchart illustrating the control method of the satellite communication simulation system proposed in this invention. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] like Figure 1 As shown, the first aspect of this application provides a satellite communication simulation system 100, including an interface control and data management module 110, a satellite network control center simulation module 120, a communication satellite simulation module 130, a ground satellite service access station simulation module 140, and an airborne satellite communication terminal simulation module 150.

[0024] The interface control and data management module 110 serves as the system's control and management center, while the other four are analog modules. Two parallel links exist between the five modules: a control link and a signal link. The control link, centered on the interface control and data management module 110, facilitates bidirectional interaction of control signaling and status data with each analog module through a unified data interface. The signal link is constructed according to the physical topology of satellite communication. Uplink signals from the ground satellite service access station analog module 140 are transparently forwarded by the communication satellite analog module 130 before reaching the airborne satellite communication terminal analog module 150; the reverse link follows the same principle. The control link and signal link are physically independent but logically correlated through a shared data pool—the control link handles parameter configuration, command issuance, and status acquisition for each module, while the signal link handles the transmission and processing of radio frequency signals or digital / analog signals.

[0025] The unified data interface can adopt a publish-subscribe communication architecture. Each module registers as a data publisher or subscriber to the unified data bus and interacts with data through topics. The data transmitted by the unified data interface adopts a standardized message format, and the message structure includes two parts: a message header and a message body. The message header contains four fields: source module identifier, destination module identifier, timestamp, and message type; the message body carries the specific business data.

[0026] For example, when the interface control and data management module 110 sends a communication networking scheme to the satellite network control center simulation module 120, it publishes a message with the subject "NetworkConfig". The source module identifier in the message header is "ICDMM" (an abbreviation for interface control and data management module 110), the target module identifier is "SMCC" (an abbreviation for satellite network control center simulation module 120), the message type is "CONFIG", and the message body carries structured data of the communication networking scheme, including subnet identifier, frequency band type, role of each station, and frequency allocation information. The satellite network control center simulation module 120 subscribes to the "NetworkConfig" topic, receives and parses the message, and generates network control parameters accordingly.

[0027] For example, when each analog module reports its operating status data to the interface control and data management module 110, it publishes a message with the subject "StatusReport". The message body carries the current operating status data of the module, including the module's online status, link connectivity, signal level, and bit error rate. The interface control and data management module 110 subscribes to the "StatusReport" topic and collects the operating status data of each analog module in real time.

[0028] The unified data interface supports both RF signal interfaces and network data interfaces. The RF signal interface transmits analog RF signals and uses standard RF connectors (such as N-type or SMA connectors) connected via RF cables. The network data interface transmits digital analog signals and control data and uses an Ethernet interface connected via network cables. Each analog module selects the appropriate interface type based on its simulation level.

[0029] The interface control and data management module 110 includes four functional sub-modules: task planning, network training, anomaly handling, and performance evaluation. These four sub-modules achieve real-time synchronization through a shared data pool.

[0030] The shared data pool is implemented using a shared memory mechanism, allocating independent data areas in system memory to store the intermediate states and output results of each functional submodule. The data in the shared data pool is organized in the form of data tables, mainly including the following data structures: (1) Task Status Table: Records basic information about the current training task, including the training task number, the current training stage (task planning, network training, anomaly handling or performance evaluation), the list of participating training stations, and the task start time. The task planning submodule writes to this table when generating training task instances, and other functional submodules read this table to obtain the task context.

[0031] (2) Network Configuration Table: Records the communication networking scheme and network control parameters, including the communication subnet identifier, frequency band type (Ku or UHF), multiple access system (FDMA or TDMA), channel unit address and frequency allocation information of each station. The network training submodule writes the generated configuration parameters into this table, and the abnormal situation handling submodule and the performance evaluation submodule read this table to obtain the network configuration context.

[0032] (3) Operation Status Table: Records the real-time operation status of each simulation module, including module identifier, online status, link status, signal level, bit error rate, and channel occupancy rate. The interface control and data management module 110 collects the operation status data of each simulation module through a unified data interface and writes it into this table. The performance evaluation submodule reads this table to perform evaluation calculations.

[0033] (4) Evaluation Index Table: Records the evaluation index data generated by the performance evaluation submodule, including the scores of each evaluation dimension, the weighted comprehensive score, and the evaluation timestamp. After the performance evaluation submodule writes the data into this table, other functional submodules can read the evaluation results to adjust subsequent training strategies.

[0034] When any functional submodule updates data in the shared data pool, it broadcasts a data change identifier to other functional submodules via an event notification mechanism. Upon receiving the change notification, other functional submodules read the updated data from the shared data pool in the next processing cycle, thus achieving real-time synchronization between the functional submodules. For example, after the network training submodule writes network control parameters into the network configuration table, it sends a data change notification to the anomaly handling submodule and the performance evaluation submodule. The anomaly handling submodule reads the updated network configuration table and uses it to determine the links and parameters where faults can be injected; the performance evaluation submodule reads the updated network configuration table and uses it to determine the calculation benchmark for the evaluation indicators.

[0035] The task planning submodule is used to construct training task scenarios and generate communication networking schemes. Training task scenarios are pre-stored as scenario files, which use a structured data format (such as XML or JSON) and contain the following: (1) List of participating stations: Records the station information participating in the training, including station identifier, station type (stationary mobile communication vehicle-mounted station, box-type station, mobile mobile communication vehicle-mounted station or airborne terminal), subnet and role (master station or slave station). For example, a scenario file defines 5 participating stations: stationary mobile communication vehicle-mounted station with station identifier GS-001, box-type station with station identifier GS-002, mobile mobile communication vehicle-mounted station with station identifier GS-003, airborne Ku terminal with station identifier AC-001 and airborne UHF terminal with station identifier AC-002.

[0036] (2) Communication Networking Scheme: Records subnet division and resource configuration information, including the number of subnets, the multiple access system (FDMA or TDMA) of each subnet, the frequency band (Ku or UHF), the frequency resource allocation of the transponder, and the channel unit address of each station. For example, the scenario file defines two sets of communication subnets: Subnet 1 is a Ku-band FDMA system, containing three stations: GS-001, GS-002, and AC-001; Subnet 2 is a UHF-band TDMA system, containing two stations: GS-003 and AC-002.

[0037] (3) Performance evaluation parameters: Record the configuration information related to the evaluation, including the weight values ​​and scoring rule parameters of each evaluation dimension. For example, the weight of the operation standardization dimension is 0.4, the weight of the network timeliness dimension is 0.3, the weight of the fault handling capability dimension is 0.3, and the preset standard time for the network timeliness dimension is 300 seconds.

[0038] After loading the scenario file, the task planning submodule parses the above content, generates training task instances and assigns a unique training task number (such as TASK-20260812-001). The training task number, the parsed list of participating training stations, the communication networking scheme, and the performance evaluation parameters are written into the task status table, network configuration table, and evaluation index table of the shared data pool for other functional submodules to read and use.

[0039] The network training submodule reads the communication network scheme from the shared data pool and generates initialization configuration parameters for each simulation module accordingly, including communication subnet identifier, frequency band configuration, multiple access system parameters, channel unit address and frequency allocation scheme of each station, and distributes the configuration parameters to the satellite network control center simulation module 120, the ground satellite service access station simulation module 140 and the airborne satellite communication terminal simulation module 150 through a unified data interface, triggering the equipment initialization and network establishment process of each simulation module.

[0040] The network establishment process includes the following steps: After receiving the configuration parameters, each simulation module completes device initialization, including radio frequency parameter configuration, baseband parameter configuration, and channel unit address setting; after initialization, each station-end simulation module initiates a network access request to the satellite network control center simulation module 120 according to the configured multiple access system; the satellite network control center simulation module 120 authenticates the network access request, and after successful authentication, allocates channel resources to the station-end and sends back a network access confirmation message; after all participating stations-ends complete the network access, the network establishment process ends, and the system enters the network communication state.

[0041] After the network is established, the interface control and data management module 110 acquires the operating status data and link quality indicators of each simulation module through a polling mechanism, and evaluates the network effect based on preset scoring rules. Link quality indicators include link connectivity, signal level, bit error rate, and link establishment delay. The evaluation results are displayed in the form of a radar chart and a quantitative scoring table. Each axis of the radar chart corresponds to a different evaluation dimension, and the quantitative scoring table lists the score for each dimension and the overall score.

[0042] The anomaly handling submodule is used to inject and handle anomalies during network communication. It reads the network configuration table and operational status table from the shared data pool to determine the links and parameter ranges where anomalies can be injected. Anomalies include two categories: equipment failure and channel degradation. Equipment failure injection is achieved by sending fault parameters to a designated simulation module. For example, injecting a fault parameter of "power amplifier gain decrease of 20dB" into a ground satellite service access station simulation module 140, or injecting a fault parameter of "antenna pointing deviation of 2 degrees" into an airborne terminal simulation module. Channel degradation injection is achieved by sending channel environment parameters to the communication satellite simulation module 130, such as injecting parameters of "rain attenuation increase of 8dB" or "Doppler shift increase of 5kHz".

[0043] The anomaly handling submodule triggers anomaly injection based on a pre-defined anomaly handling plan or received control commands. Control commands are received through a unified data interface, and command types include "inject fault," "recover fault," "switch scene," "pause training," and "resume training." Each control command contains the target module identifier, fault type, and fault parameters.

[0044] The exception handling submodule, while injecting exceptions, records the sequence of handling operations and the operation time input by the user through each simulation module, and writes the operation log to the shared data pool for the performance evaluation submodule to read and use.

[0045] The performance evaluation submodule reads data from the operation status table, operation log, and evaluation index table from the shared data pool, and performs quantitative scoring from three dimensions: operation standardization, network timeliness, and fault handling capability, according to the corresponding scoring rules and weights in the performance evaluation parameters.

[0046] The operational standardization score is calculated based on the consistency rate and sequence accuracy rate between the user's actual operational steps and the standard operating procedure template. The consistency rate refers to the proportion of operational steps that are consistent with the standard operating procedure template out of the total number of operational steps actually performed; the sequence accuracy rate refers to the proportion of the actual operational steps that are executed in the order defined in the standard operating procedure template.

[0047] The network deployment timeliness score is calculated based on the ratio of the total time from the issuance of the network deployment command to the completion of network access for all participating stations to the preset standard time in the performance evaluation parameters. When the total time is less than or equal to the preset standard time, the network deployment timeliness score is full; when the total time exceeds the preset standard time, the score is reduced proportionally.

[0048] The fault handling capability score is calculated based on the operator's fault location time and the correctness of the handling plan. The location time refers to the interval between the fault injection time and the time when the operator performs the correct handling operation; the correctness of the handling plan refers to whether the sequence of handling operations performed by the operator can eliminate the injected fault and restore normal communication.

[0049] The three evaluation dimensions are weighted and averaged according to their respective weights in the performance evaluation parameters to obtain the final evaluation result for the user. The performance evaluation submodule writes the scores of each dimension, the weighted composite score, and the evaluation timestamp into the evaluation index table in the shared data pool for other functional submodules to access synchronously. For example, when the evaluation index indicates that the operational standardization score of a certain station is low, the network training submodule can adjust the training difficulty configuration of that station accordingly; when the network timeliness score is below the threshold, the task planning submodule can adjust the network scheme in the next training task.

[0050] The interface control and data management module 110 also includes a training and evaluation docking unit. The training and evaluation docking unit is a standardized data interaction channel between the interface control and data management module 110 and the external evaluation system, responsible for realizing information exchange between the simulation system and the external evaluation system.

[0051] The training and evaluation interface unit establishes a standardized data exchange interface with the external evaluation system. The data exchange interface uses standard network protocols (such as TCP / IP), and the interface specification includes data format definitions, transmission protocols, interaction timing, and interface address definitions. The data format uses a structured markup language (such as XML or JSON). Each data message includes a header and a body. The header carries the message type, source address, destination address, and sequence number, while the body carries the specific business data. The external evaluation system refers to an external hardware and software system that operates independently of the satellite communication simulation system 100 and is used for comprehensive evaluation and recording of the training process and training results.

[0052] Through the data exchange interface, the training and evaluation docking unit achieves the following bidirectional data interaction: (1) Receiving direction: Receive task plan files, directing and control instructions and task role configuration information from external evaluation systems.

[0053] The task plan file includes the training task's schedule, training phase divisions, and training objectives for each phase. For example, an external evaluation system issues a task plan file specifying the training task number as TASK-20260812-001. The training phases are divided into: task planning phase (0 to 5 minutes), network training phase (5 to 20 minutes), anomaly handling phase (20 to 35 minutes), and performance evaluation phase (35 to 40 minutes). The training objectives for each phase are: completing network configuration loading, completing network link establishment, completing fault handling, and completing performance evaluation. After receiving the file, the training evaluation interface unit parses it and writes it to the task status table in the shared data pool. The task planning submodule reads the plan from the shared data pool and drives each training phase according to the planned schedule.

[0054] The guidance and control commands include command types such as "inject fault," "recover fault," "switch scenario," "pause training," and "resume training." Each command contains a target module identifier, fault type, and fault parameters. After receiving the guidance and control commands, the training and evaluation docking unit forwards the commands to the anomaly handling submodule for execution. For example, during the anomaly handling phase, the external evaluation system issues an "inject fault" command with the target module identifier GS-001, the fault type "power amplifier gain decrease," and the fault parameter "20dB." The training and evaluation docking unit forwards this command to the anomaly handling submodule, which then sends the fault parameters to the ground satellite service access station simulation module 140 corresponding to GS-001.

[0055] The task role configuration information includes the role identifier, affiliated station, and operation permissions of the participating operators. For example, the task role configuration information defines three operators: User ID U-001, role "Master Station Operator", affiliated station GS-001, operation permission "All Operations"; User ID U-002, role "Slave Station Operator", affiliated station GS-002, operation permission "Communication Operations"; User ID U-003, role "Airborne Terminal Operator", affiliated station AC-001, operation permission "Communication Operations". The training and evaluation docking unit writes the task role configuration information into the task status table of the shared data pool, and each functional submodule identifies the identity and permissions of the current operator based on this information.

[0056] (2) Transmission direction - Read the communication link operation data, channel resource usage data and operation status data of each simulation module from the shared data pool, and generate performance evaluation indicators based on the read data.

[0057] Communication link operation data includes the connectivity status of each communication link, link establishment delay, and link quality indicators (such as bit error rate and signal level). For example, the connectivity status of link GS-001 to AC-001 is "on," the link establishment delay is 15 seconds, and the bit error rate is 1.2 × 10⁻⁶. -6 The signal level is -85dBm.

[0058] Channel resource usage data includes channel occupancy rate, frequency resource usage status, and time slot allocation status for each communication subnet. For example, the channel occupancy rate of subnet 1 (Ku band FDMA system) is 75%, and the frequency resources of all 3 stations have been allocated; the channel occupancy rate of subnet 2 (UHF band TDMA system) is 50%, and 2 out of 4 time slots have been allocated.

[0059] The operational status data includes the online status of each analog module and the equipment operating parameters. For example, all five analog modules are online, the transmitter output power of GS-001 is 20dBW, and the received signal level of AC-001 is -85dBm.

[0060] The training and evaluation docking unit calculates performance evaluation indicators based on the above data according to the performance evaluation index system. These indicators include link quality scores for each communication link, channel resource utilization, network deployment timeliness, and fault handling timeliness. For example, based on the bit error rate of 1.2 × 10⁻⁶ for the GS-001 to AC-001 link... -6 (Better than threshold 1×10) -5 The link quality score is rated as "excellent"; the channel occupancy rate of subnet 1 is 75%, and the channel resource utilization rate is 75%; the total network establishment time is 270 seconds (lower than the preset standard time of 300 seconds), and the network timeliness indicator is "compliant"; the fault location time is 45 seconds and the handling plan is correct, and the fault handling timeliness indicator is "qualified".

[0061] The training and evaluation interface unit reports the generated performance evaluation metrics to the external evaluation system via a data exchange interface, allowing the external evaluation system to conduct comprehensive assessments, record results, and manage training archives. Simultaneously, the training and evaluation interface unit writes the performance evaluation metrics into the evaluation metric table in the shared data pool for synchronous use by various functional submodules. For example, when the performance evaluation metrics indicate that the bit error rate of a certain communication link is consistently higher than 1×10⁻⁶, the unit will provide a performance evaluation result. -3 When the abnormal situation handling submodule reads the indicator from the shared data pool, it triggers an alarm for link quality deterioration or automatically adjusts the subsequent fault injection strategy accordingly. When the network timeliness indicator is lower than the preset threshold, the task planning submodule can adjust the complexity of the network scheme in the next training task accordingly.

[0062] The interface control and data management module 110 acquires the operating status data of each simulation module through a polling mechanism. The polling period is configurable, for example, set to 1 second. Within each polling period, the interface control and data management module 110 sequentially sends status query messages to each simulation module through a unified data interface, and each simulation module responds and returns its current operating status data. The operating status data includes the following: Module Online Status: Indicates whether the module is operating normally, with a value of online or offline; Link Status: Indicates the connectivity status of the communication link, with a value of on or off; Signal Level: The level value of the received signal, in dBm, e.g., -85dBm; Bit Error Rate: The bit error rate indicator of the link, e.g., 1.2×10⁻⁶. -6 Channel occupancy rate: The proportion of channel resources occupied, for example, 75%.

[0063] The collected operational status data is written to the operational status table in the shared data pool for the performance evaluation submodule and other functional submodules to read and use.

[0064] The satellite network control center simulation module 120 is used to simulate network management and station control functions in a satellite communication network. Network management functions include communication subnet configuration, channel resource allocation, and simulation of network entry / exit signaling interactions.

[0065] Communication Subnet Configuration: Based on the communication networking scheme provided by the interface control and data management module 110, the satellite network control center simulation module 120 configures the subnet identifier, frequency band type, multiple access system, and frequency resources for each communication subnet. For example, for subnet 1 (Ku-band FDMA system), the subnet identifier is configured as NET-01, the uplink frequency band is 14.0-14.5GHz, the downlink frequency band is 12.25-12.75GHz, and each station is allocated an independent uplink carrier frequency—GS-001 is allocated 14.25GHz, GS-002 is allocated 14.30GHz, and AC-001 is allocated 14.35GHz, while sharing the downlink carrier frequency of 12.50GHz.

[0066] Channel resource allocation: For FDMA subnets, each station is allocated an independent carrier frequency and bandwidth (e.g., 36MHz); for TDMA subnets, each station is allocated a time slot on a shared carrier. For example, in subnet 2 (UHF band TDMA system), GS-003 is allocated time slots 1 and 2, and AC-002 is allocated time slots 3 and 4. Each time slot is 20 milliseconds long, and the frame period is 80 milliseconds.

[0067] Simulation of Network Entry and Departure Signaling Interaction: The satellite network control center simulation module 120 simulates the interaction process of network entry and departure signaling. The network entry process is divided into two categories based on the multiple access system: FDMA network entry process and TDMA network entry process. For an FDMA subnet, the network entry process is as follows: The station sends a network entry request message on the control ALOHA channel, containing the station's channel unit address, user number, and requested service type; upon receiving the network entry request message, the network control center queries a preset authentication table to verify the legality of the channel unit address and user number; if verification is successful, a network entry confirmation response is sent to the station on the TDM broadcast channel, allocating channel resources to the station and marking the station's channel unit status as online; if verification fails, a network entry rejection response message is sent on the TDM broadcast channel, containing the corresponding rejection reason code. For TDMA subnets, the network access process is as follows: The station sends a network access request message on its reserved network access time slot. The message includes the station's channel unit address, user number, and the type of service requested. Upon receiving the request message, the network control center queries a pre-set authentication table to verify the legitimacy of the channel unit address and user number. If verification is successful, a network access confirmation response is sent to the station on the TDM broadcast channel, allocating a communication time slot to the station and marking the station's channel unit status as online. If verification fails, a network access rejection response message is sent on the TDM broadcast channel. The network decommissioning process is as follows: The station sends a network decommissioning request message. Upon receiving this message, the network control center releases the channel resources occupied by the station and marks the station's channel unit status as offline.

[0068] The station control functions include equipment status monitoring and parameter distribution. The satellite network control center simulation module 120 sends status query commands to each station's simulation module via a unified data interface according to a set polling cycle (e.g., 1 second), collecting equipment operating status data from each station, including equipment online status, transmitter output power, received signal level, and link quality indicators. The network control center then aggregates the collected status data and reports it to the interface control and data management module 110 via the unified data interface.

[0069] The satellite network control center simulation module 120 supports the parallel management and control of multiple communication subnets. Each communication subnet maintains an independent resource allocation table, including its subnet identifier, station list, frequency resource pool, and channel resource usage status. The network control center distinguishes the signaling and data of different subnets through the subnet identifier, and the frequency and channel resources of each subnet are isolated from each other.

[0070] For example, the system operates two communication subnets simultaneously: Subnet 1 uses a Ku-band FDMA system, employing the 14.0-14.5GHz uplink band; Subnet 2 uses a UHF-band TDMA system, employing the 300-318MHz uplink band. The frequency resources of the two subnets do not overlap. Signaling is routed using subnet identifiers, and each subnet independently executes its network entry / exit procedures and resource allocation without interference. The network control center maintains independent authentication and resource allocation tables for each subnet, indexing the corresponding table entries using the subnet identifier to achieve parallel management and control.

[0071] The satellite network control center simulation module 120 uses a parametric simulation configuration method to generate network control parameters for the FDMA integrated service network and the TDMA integrated service network. Parametric simulation configuration means that the satellite network control center simulation module 120 does not write separate simulation programs for each satellite model and each communication system. Instead, it automatically matches and generates corresponding network control parameters based on the configuration of the communication network scheme by calling parameter templates from a pre-built parameter library. This achieves universal support for different satellite models and different communication systems from the same simulation platform.

[0072] The satellite network control center simulation module 120 pre-establishes the following three parameter libraries: (1) Satellite transponder parameter library: Stores the technical parameters of transponders for different types of communication satellites. It is organized in the form of structured data tables. Each record includes satellite model identifier, transponder number, frequency band type (Ku or UHF), uplink frequency range, downlink frequency range, transponder bandwidth, saturated equivalent isotropic radiated power, receiving system quality factor (G / T) and transponder gain.

[0073] For example, the satellite transponder parameter database stores two records: Record 1 corresponds to the Ku-band transponder of the "Sat-A" satellite, with an uplink frequency range of 14.0 to 14.5 GHz, a downlink frequency range of 12.25 to 12.75 GHz, a transponder bandwidth of 36 MHz, a saturated equivalent isotropic radiated power of 52 dBW, a G / T of 3 dB / K, and a transponder gain of 120 dB; Record 2 corresponds to the UHF-band transponder of the "Sat-B" satellite, with an uplink frequency range of 300 to 318 MHz, a downlink frequency range of 248 to 270 MHz, a transponder bandwidth of 25 kHz, a saturated equivalent isotropic radiated power of 30 dBW, a G / T of -5 dB / K, and a transponder gain of 100 dB.

[0074] (2) Beam coverage model library: stores beam coverage range models of different types of communication satellites. Each record includes satellite model identifier, beam identifier, beam type (global beam, regional beam or point beam), beam center latitude and longitude, beam coverage range boundary coordinates and beam gain distribution parameters.

[0075] For example, the beam coverage model library stores a record corresponding to a Ku-band spot beam for a "Sat-A" satellite, identified as "BEAM-KU-01," with its center located at 105°E, 35°N, a coverage radius of 1500km, a center gain of 40dBi, and an edge gain of 32dBi. When a ground satellite service access station's geographical location falls within the beam coverage area, the beam gain value at that station's location is determined by linear interpolation of its distance from the beam center.

[0076] (3) Channel template library: Stores channel configuration parameter templates for different communication systems. Each record includes template identifier, multiple access system type (FDMA or TDMA), frequency band type (Ku or UHF), carrier bandwidth, modulation method, coding method, information rate and channel unit address allocation rules.

[0077] For example, the channel template library stores two records: Record 1 has a template identifier of "Ku-FDMA-TMPL-01", the multiple access system is FDMA, the frequency band is Ku, the carrier bandwidth is 36MHz, the modulation method is QPSK, the coding method is LDPC, the information rate is 2Mbps, and the channel unit address is allocated incrementally starting from 0x01; Record 2 has a template identifier of "UHF-TDMA-TMPL-01", the multiple access system is TDMA, the frequency band is UHF, the carrier bandwidth is 25kHz, the modulation method is QPSK, the coding method is convolutional code, the information rate is 64kbps, the time slot length is 20ms, the frame period is 80ms, and the channel unit address is allocated incrementally starting from 0x01.

[0078] During the simulation, the satellite network control center simulation module 120 automatically matches the corresponding parameters from the three parameter libraries mentioned above, based on the communication networking scheme provided by the task planning submodule of the interface control and data management module 110. The matching process is as follows: The satellite network control center simulation module 120 extracts the satellite model identifier, frequency band type, and multiple access system type from the communication networking scheme as matching keys. First, it matches the corresponding transponder parameters in the satellite transponder parameter library according to the satellite model identifier and frequency band type; then, it matches the corresponding beam coverage range model in the beam coverage model library according to the satellite model identifier and beam identifier; finally, it matches the corresponding channel template parameters in the channel template library according to the multiple access system type and frequency band type.

[0079] For example, in the communication networking scheme, the satellite model is specified as "Sat-A", the frequency band is Ku, and the multiple access system is FDMA. The satellite network control center simulation module 120 first matches record 1 from the satellite transponder parameter library according to "Sat-A" and "Ku"—uplink 14.0 to 14.5 GHz, downlink 12.25 to 12.75 GHz, bandwidth 36 MHz, saturated equivalent isotropic radiated power 52 dBW, G / T is 3 dB / K, and transponder gain is 120 dB; then it matches the Ku band point beam model from the beam coverage model library according to "Sat-A"—coverage radius 1500 km, center gain 40 dBi; finally, it matches the "Ku-FDMA-TMPL-01" template from the channel template library according to "FDMA" and "Ku"—QPSK modulation, LDPC coding, and 2 Mbps information rate. After the matching is completed, the satellite network control center simulation module 120 combines the above parameters to generate network control parameters, including communication subnet identifier, frequency band configuration, carrier bandwidth, modulation and coding scheme and channel unit address allocation scheme.

[0080] Based on the parameter database matching results, the satellite network control center simulation module 120 calculates the uplink effective omnidirectional radiated power of each ground satellite service access station using the following formula: ; in, The uplink effective omnidirectional radiated power of the ground satellite service access station, in dBW; This represents the antenna transmit gain, measured in dBi. This refers to the feeder insertion loss, in dB. This represents the transmitter output power, measured in dBW. All quantities are expressed in decibels, and the operations in the expressions are algebraic addition and subtraction in the decibel domain. Quantities in the decibel domain are dimensionless logarithmic values. Antenna transmit gain... It is the logarithm of 10 times the antenna gain. =10lg(G), where G is the antenna linear gain), and the transmitter output power. It is the logarithm of 10 times the power. =10lg(P / ), (Reference power is 1W), feeder insertion loss It is 10 times the logarithm of the loss ( =10lg(1 / L), where L is the linear loss factor. Therefore, the subtraction and addition operations in the formula correspond to the division and multiplication operations in the linear domain in the decibel domain, and their dimensions are consistent.

[0081] For example, the antenna transmit gain of a certain ground satellite service access station The feeder insertion loss is 43 dBi (corresponding to a linear gain of approximately 20,000 times). The transmitter output power is 3dB (corresponding to a linear loss of approximately 0.5 times). If the value is 20 dBW (corresponding to 100 W), then the effective uplink isotropic radiated power at this station is: =43-3+20=60dBW.

[0082] The satellite network control center simulation module 120 will calculate the uplink The power flux density at the satellite receiver is calculated using the value and preset satellite link distance parameters. This power flux density is then compared with the saturation flux density parameter of the corresponding transponder in the satellite transponder parameter library to determine if it exceeds the saturation threshold. Simultaneously, the uplink... The value is compared with the reception threshold to determine whether the minimum reception requirements are met. If the power flux density exceeds the saturation flux density, the satellite network control center simulation module 120 sends a power overload warning to the station during the network access authentication phase; if the uplink... If the value is lower than the receive threshold, a message indicating insufficient power will be sent, prompting the user to adjust the transmit power or check the antenna direction.

[0083] The communication satellite simulation module 130 is used to simulate the transparent forwarding function of a communication satellite. Transparent forwarding means that the satellite transponder only performs frequency conversion and power amplification on the uplink signal, without demodulating, decoding, or remodulating the signal; the modulation method and encoding format of the signal remain unchanged during the forwarding process. This contrasts with processing forwarding (also known as regenerative forwarding), which demodulates, decodes, and remodulates the signal. This embodiment uses transparent forwarding, consistent with the operation of a real communication satellite transponder.

[0084] The communication satellite simulation module 130 receives uplink radio frequency signals or digital analog signals, and generates downlink signals and outputs them after passing them through low-noise amplification, downconversion, intermediate frequency filtering and upconversion in sequence.

[0085] Taking the Ku band as an example, the signal processing chain is as follows: After the uplink Ku band RF signal (14.0-14.5GHz) is input, it is first amplified by a low-noise amplifier. The low-noise amplifier has a gain of 55dB and a noise figure of 4dB, amplifying the weak uplink signal to a level suitable for subsequent processing. The amplified signal is then input to a downconverter, which converts the Ku band RF signal to an intermediate frequency (IF) signal. The IF frequency is 140MHz, and the local oscillator frequency is 14.14GHz. The IF signal is then filtered by an IF filter with a bandwidth of 36MHz (corresponding to the standard transponder bandwidth) to filter out out-of-band interference signals. The filtered IF signal is then leveled by an automatic gain control circuit to stabilize the output signal level. The leveled IF signal is then input to an upconverter, which converts the IF signal back to a Ku band downlink RF signal with a downlink frequency of 12.25-12.75GHz and a local oscillator frequency of 12.39GHz. Finally, the signal is amplified by a power amplifier and output to the downlink.

[0086] Taking the UHF band as an example, the signal processing link is as follows: The uplink UHF band radio frequency signal (300-318MHz) is amplified by a low-noise amplifier (gain 50dB, noise figure 3dB), then converted to an intermediate frequency signal (intermediate frequency 70MHz, local oscillator frequency 230MHz) by a downconverter. After being filtered by an intermediate frequency filter (bandwidth 25kHz) and adjusted by automatic gain control, it is converted to a downlink UHF band radio frequency signal (248-270MHz, local oscillator frequency 178MHz) by an upconverter, and then amplified by a power amplifier before being output.

[0087] When the communication satellite analog module 130 receives a digital analog signal instead of a radio frequency (RF) signal, signal processing is completed in the digital domain. The uplink digital analog signal is digitally down-converted to baseband, digitally filtered and gain-adjusted in the baseband domain, and then digitally up-converted back to the downlink digital analog signal for output. The signal link processed in the digital domain corresponds functionally to the signal link processed in the RF domain, the difference being that the signal exists in digital form and does not pass through physical RF devices.

[0088] The communication satellite simulation module 130 supports simultaneous relay simulation in both the Ku-band and UHF bands. The relay links for the two bands are physically independent, each with its own independent low-noise amplifier, frequency converter, filter, and power amplifier. The Ku-band and UHF-band links can operate simultaneously, processing uplink signals and outputting downlink signals for their respective bands. Key parameters for each band are as follows: Ku-band: Uplink frequency range 14.0-14.5 GHz, downlink frequency range 12.25-12.75 GHz, intermediate frequency 140 MHz, transponder bandwidth 36 MHz, low-noise amplifier gain 55 dB, noise figure 4 dB; UHF band: Uplink frequency range 300-318 MHz, downlink frequency range 248-270 MHz, intermediate frequency 70 MHz, transponder bandwidth 25 kHz, low-noise amplifier gain 50 dB, noise figure 3 dB.

[0089] The Ku-band forwarding RF simulator of the communication satellite simulation module 130 adopts a single-conversion architecture to achieve transparent forwarding processing of uplink Ku-band RF signals to downlink Ku-band RF signals. The single-conversion architecture refers to the uplink RF signal undergoing one downconversion to an intermediate frequency (IF), followed by IF filtering and automatic gain control, and then one upconversion to recover the downlink RF signal. Compared to the two-conversion architecture (uplink RF → IF1 → IF2 → downlink RF), this reduces the number of conversion stages, simplifies the link structure, and lowers the combined frequency interference and noise introduced during the conversion process.

[0090] The signal processing chain of the Ku-band repeater RF simulator is as follows: The received uplink Ku-band RF signal (14.0 to 14.5 GHz) is first amplified by a low-noise amplifier (LNOA). The LNOA has a gain of 55 dB and a noise figure of 4 dB, amplifying the weak uplink signal to a level suitable for subsequent processing. The amplified signal is then input to a downconverter, which mixes the Ku-band RF signal with the local oscillator signal, converting it to an intermediate frequency (IF) signal at 140 MHz and a local oscillator frequency of 14.14 GHz. The IF signal is then further processed by the intermediate frequency converter. The filter performs filtering with a bandwidth of 36MHz (corresponding to the standard transponder bandwidth) to filter out out-of-band interference signals and image frequency components generated by mixing. The filtered intermediate frequency (IF) signal is level-adjusted by an automatic gain control circuit to keep the output signal level stable. The adjusted IF signal is input to an upconverter, which mixes the IF signal with the local oscillator signal, converting it once into a downlink Ku-band radio frequency signal (12.25 to 12.75 GHz) with a local oscillator frequency of 12.39 GHz. Finally, it is amplified by a power amplifier and output to the downlink.

[0091] The local oscillator signals for both the up-converter and down-converter are provided by a common-local-oscillator phase-locked loop (PLL) frequency synthesizer. Common-local-oscillator means that the up-converter and down-converter share the same local oscillator signal output from the same PLL frequency synthesizer, rather than each using an independent local oscillator source. Specifically, the PLL frequency synthesizer uses a high-stability temperature-compensated crystal oscillator (TCXO) as its reference clock at a frequency of 10MHz and a frequency stability of ±0.5ppm. The PLL frequency synthesizer generates the required local oscillator frequency signal through a PLL and a programmable frequency divider. This local oscillator signal is then split into two paths by a power divider—one path supplies the down-converter as its down-conversion local oscillator signal (frequency 14.14GHz), and the other path supplies the up-converter as its up-conversion local oscillator signal (frequency 12.39GHz).

[0092] The advantages of using a common local oscillator (LoLO) design are as follows: The up-conversion and down-conversion use the same LoLO source. The phase noise and frequency drift of the LoLO signal are correlated during the up-conversion and down-conversion processes. The LoLO phase noise introduced by the down-conversion is from the same source and in phase with the LoLO phase noise introduced by the up-conversion, thus canceling each other out during the overall signal processing of the transponder. This ensures that the frequency conversion accuracy of the transponder's output signal relative to the input signal is determined solely by the stability of the reference clock, and is unaffected by the independent drift of the LoLO source. For example, if the reference clock of a phase-locked loop (PLL) frequency synthesizer is a 10MHz temperature-compensated crystal oscillator (frequency stability ±0.5ppm), the corresponding frequency error of the 10MHz reference clock is ±5Hz. After PLL frequency multiplication, the frequency error of the 14.14GHz LoLO signal is ±7.07kHz, and the frequency error of the 12.39GHz LoLO signal is ±6.20kHz. Because a common local oscillator is used, the frequency errors of the two local oscillator signals originate from the same reference clock and are in the same direction. They cancel each other out during the down-conversion and up-conversion mixing processes. The frequency error of the actual output signal is determined only by the reference clock (±0.5ppm, which corresponds to approximately ±7kHz for a 14GHz signal). This is better than the case where the errors are superimposed when using two independent local oscillator sources (±7.07kHz + ±6.20kHz = ±13.27kHz).

[0093] The overall gain and noise figure of the Ku-band repeater RF simulator are calibrated according to the model parameters of the communication satellite being simulated. Calibration refers to adjusting the gain distribution and noise parameters of each stage of the Ku-band repeater RF simulator circuitry to match the transponder specifications of the simulated satellite, taking into account the transponder characteristics of different satellite models. The calibration process is as follows: Based on the transponder gain, saturated equivalent isotropic radiated power, and noise figure of the corresponding satellite model from the satellite transponder parameter library, the gain distribution scheme of each stage of the Ku-band repeater RF simulator circuitry is calculated—the gain of the low-noise amplifier, the gain of the intermediate frequency amplifier, and the gain of the power amplifier, as well as the noise figure of each stage of the circuitry.

[0094] For example, when simulating the Ku-band transponder of the "Sat-A" satellite, based on the parameters of this transponder model in the satellite transponder parameter library—transponder gain 120dB and noise figure 4dB—the parameters of each stage of the Ku-band transponder RF simulator are calibrated as follows: low-noise amplifier gain 55dB and noise figure 4dB, intermediate frequency amplifier (including automatic gain control circuit) gain 50dB, power amplifier gain 15dB, and the overall gain is 55+50+15=120dB. The overall noise figure is determined by the low-noise amplifier (according to the cascaded noise figure formula, the noise figure of the first-stage amplifier contributes the most to the overall noise figure), approximately 4dB, which is consistent with the transponder parameters of the "Sat-A" satellite. When switching to simulate another type of satellite, such as the "Sat-C" satellite with a transponder gain of 110dB and a noise figure of 5dB, the transponder parameters are read again from the parameter library and the gain distribution of each stage is recalibrated—low noise amplifier gain 50dB, noise figure 5dB, intermediate frequency amplifier gain 45dB, power amplifier gain 15dB, overall gain 110dB, and overall noise figure 5dB.

[0095] The communication satellite simulation module 130 supports dynamic updates of channel environment parameters. These parameters are used to simulate transmission impairments encountered by signals during space transmission, including multipath fading model parameters, rain attenuation parameters, Doppler shift parameters, and co-channel interference signal parameters.

[0096] Multipath fading model parameters are used to simulate the fading effect of a signal reaching the receiver after traveling through multiple paths. These parameters include the number of multipath paths, the delay of each path, and the power ratio of each path. Rain attenuation parameters are used to simulate the attenuation of satellite signals caused by rainfall. These parameters include the rainfall rate and the amount of attenuation, calculated based on the rainfall rate according to the model in ITU-R Recommendation P.618. Doppler frequency shift parameters are used to simulate the frequency shift caused by the motion of an airborne platform relative to the satellite. These parameters include the platform's motion speed, direction of motion, and the amount of frequency shift, calculated based on the platform's motion speed and carrier frequency. Co-channel interference signal parameters are used to simulate the interference of other signals in the same frequency band to this signal. These parameters include the interference signal power and the interference signal frequency offset.

[0097] Channel environment parameters can be obtained in two ways: first, automatically calculated by the system's internal channel model based on preset conditions, such as calculating rain attenuation based on a preset rainfall rate; second, injected by external channel and environment simulation equipment. Channel environment parameter updates employ a combination of event-triggered and periodic updates. The default period for periodic updates is 1 second, which can be adjusted according to training requirements. Event-triggered updates are executed immediately when specific conditions are met, such as updating the Doppler shift parameters of a station immediately when it is detected that the station has switched from a stationary state to a mobile state. The updated channel environment parameters are applied to the forwarding link of the communication satellite simulation module 130, imposing corresponding transmission impairments on the forwarded signals.

[0098] The communication satellite simulation module 130 dynamically updates channel environment parameters through a channel environment simulation unit. The channel environment simulation unit is an independent functional unit within the communication satellite simulation module 130, responsible for receiving, parsing, and applying channel environment parameters from external channel and environment simulation equipment.

[0099] The channel environment simulation unit establishes a unified RF signal interface and network data interface with the external channel and environment simulation equipment. The RF signal interface is used to transmit RF simulation signals related to the channel environment, and is connected via RF cable using a standard RF connector (such as an N-type or SMA interface). The network data interface is used to transmit channel environment parameter data and control commands, and is connected via network cable using an Ethernet interface. The external channel and environment simulation equipment can be a standalone channel simulator hardware device or a computing platform running channel simulation software, achieving bidirectional interaction between the signal and data levels with the channel environment simulation unit through the aforementioned two interfaces.

[0100] The channel environment simulation unit receives channel environment parameters injected by external channel and environment simulation equipment through a network data interface. The channel environment parameters include the following four categories: (1) Multipath fading model parameters: These are used to simulate the fading effect that occurs when a signal travels through multiple paths to the receiver. The parameters include the number of multipaths, the delay of each path, and the power ratio of each path. For example, the number of multipaths is set to 4, the delays of each path are 0μs, 0.5μs, 1.0μs and 1.5μs, and the power ratios of each path are 0dB, -3dB, -6dB and -9dB, respectively, to simulate the multipath propagation environment in the urban-rural fringe.

[0101] (2) Rain attenuation parameters: These are used to simulate the attenuation of satellite signals caused by rainfall. The parameters include the rainfall rate and the attenuation amount. The attenuation amount is calculated based on the rainfall rate according to the model in ITU-R Recommendation P.618. For example, if the rainfall rate is set to 25 mm / h (moderate rain), the rain attenuation amount in the Ku band is calculated to be approximately 8 dB; if the rainfall rate is set to 50 mm / h (heavy rain), the rain attenuation amount is approximately 15 dB.

[0102] (3) Doppler frequency shift parameters: These are used to simulate the frequency shift caused by the airborne platform's motion relative to the satellite. The parameters include the platform's motion speed, direction of motion, and frequency shift amount. The frequency shift amount is calculated based on the platform's motion speed and carrier frequency. For example, when the airborne platform flies at a speed of 800 km / h, the Doppler frequency shift generated in the Ku band (carrier frequency 14 GHz) is approximately 10.4 kHz; the Doppler frequency shift generated in the UHF band (carrier frequency 300 MHz) is approximately 0.22 kHz.

[0103] (4) Co-channel interference signal parameters: These are used to simulate interference from other signals in the same frequency band to this signal. The parameters include the interference signal power and the interference signal frequency offset. For example, the interference signal power is set to be 20dB lower than the main signal and the interference signal frequency offset is 100kHz to simulate a neighboring satellite interference scenario.

[0104] After receiving the channel environment parameters, the channel environment simulation unit distributes the parameters to two processing links—the radio frequency simulation link and the digital simulation link (i.e., the baseband domain processing link). The communication satellite simulation module 130 determines the radio frequency domain transmission impairment and the baseband domain transmission impairment based on the channel environment parameters.

[0105] Radio frequency (RF) domain transmission impairment refers to the impairment parameters applied to the RF analog link, manifested as changes in the physical characteristics of the RF signal. For example, 8dB rain attenuation manifests as an 8dB reduction in RF signal power in the RF domain, achieved by setting an adjustable attenuator at the power amplifier output; a 10.4kHz Doppler shift manifests as a 10.4kHz shift in the RF domain, achieved by applying a corresponding frequency shift to the local oscillator frequency in the upconverter; multipath fading effects manifest as amplitude and phase fluctuations in the RF signal in the RF domain, achieved through multipath analog circuitry in the RF domain; and co-channel interference manifests as superimposed interfering RF signals in the RF domain, achieved through a signal synthesizer. RF domain transmission impairment is directly applied to the RF signal processing link of the communication satellite simulation module 130.

[0106] Baseband domain transmission impairment refers to the impairment parameters applied to the digital-analog link (baseband domain processing link), expressed in the mathematical form of the digital baseband signal. For example, multipath fading in the baseband domain is represented by the convolution operation of the baseband signal with the complex fading coefficients of each path; rain attenuation of 8dB in the baseband domain is represented by the digital attenuation of the baseband signal amplitude (multiplied by 10^(-8 / 20)≈0.398); Doppler shift in the baseband domain is represented by the phase rotation of the baseband signal; co-channel interference in the baseband domain is represented by the digital superposition of interfering baseband signals. The baseband domain transmission impairment is applied to the digital domain signal processing link of the communication satellite analog module 130—superimposing the corresponding fading, attenuation, and frequency shift effects onto the digitally down-converted baseband signal.

[0107] Transmission impairments in the RF analog link and the digital analog link are updated synchronously. The synchronous update mechanism is as follows: When the channel environment simulation unit receives new channel environment parameters or detects a change in parameters, it simultaneously writes the updated parameters into the parameter registers of both the RF analog link and the digital analog link. The two registers are loaded with the new parameters synchronously on the rising edge of the same clock cycle, thereby ensuring that transmission impairments in the RF domain and the baseband domain take effect at the same time.

[0108] For example, when an external channel and environment simulation device injects a parameter update stating that "rain attenuation is increased from 5dB to 8dB," the channel environment simulation unit simultaneously updates the RF domain attenuation from 5dB to 8dB (applied to the adjustable attenuator of the RF link, adjusting its attenuation from 5dB to 8dB) and the baseband domain attenuation from 5dB to 8dB (applied to the digital gain regulator of the digital link, adjusting its attenuation coefficient from 10^(-5 / 20)≈0.562 to 10^(-8 / 20)≈0.398). The signals of both links are synchronously subjected to 8dB of rain attenuation within the same processing cycle. This synchronous update ensures that the RF simulation link and the digital simulation link respond consistently to changes in the same channel environment parameter at the same time, avoiding time differences in transmission impairments between the two links that could lead to inconsistent simulation results.

[0109] The ground satellite service access station simulation module 140 is used to simulate three types of ground satellite communication station terminals: stationary mobile communication station, box-type station, and mobile mobile communication station.

[0110] A stationary vehicle-mounted satellite communication station (SMS station) is a device mounted on a vehicle platform that deploys its antenna and communicates with a satellite while stationary. Its key feature is that the antenna deploys and completes satellite alignment after the vehicle comes to a complete stop, and the antenna attitude remains fixed throughout the communication process. Simulations must replicate the equipment's operational procedures across four phases: antenna deployment, satellite alignment, tracking, and communication. For example, the antenna deployment process of a SMS station includes unlocking the antenna locking device, raising the antenna to its operating position, and adjusting the antenna's azimuth and elevation angles to align with the satellite.

[0111] Box-type stations: These are satellite communication stations encapsulated in a portable box, suitable for temporary deployment and rapid setup. They are characterized by their compact size and ease of transport, but require manual assembly of the antenna and connection of the RF cable during setup. Simulations must mimic the equipment assembly, parameter configuration, and communication establishment process. For example, the setup process for a box-type station includes unpacking and removing the antenna surface and RF unit, assembling the antenna, connecting the RF cable, configuring station parameters, and initiating network access.

[0112] Mobile satellite communication station: This refers to a satellite communication station mounted on a vehicle platform that maintains satellite communication while in motion. Its key feature is an antenna with automatic tracking capability, which can adjust the antenna pointing in real time to track the satellite while the vehicle is moving. Simulations require simulating antenna tracking, Doppler shift compensation, and communication maintenance during movement. For example, the mobile satellite communication station calculates the adjustment of the antenna pointing angle in real time based on preset vehicle motion parameters (including speed, heading, and position changes) and simulates the corresponding Doppler shift effect.

[0113] The ground satellite service access station simulation module 140 achieves full-level simulation coverage through a radio frequency operation simulator, a hardware-in-the-loop operation simulator, and a digital operation simulator. The three simulators differ in signal characteristics, equipment access methods, and applicable scenarios.

[0114] Digital Operation Simulator: This simulator runs station-end equipment simulation software on a computer. It transmits and receives digital analog signals through a unified data interface, simulating the station-end equipment's operation interface, parameter configuration process, and service processing logic without generating real radio frequency signals. The digital operation simulator is suitable for large-scale network deployment simulations and basic operation training scenarios. Its advantages include low deployment cost, flexible configuration, and the ability to simulate a large number of virtual stations simultaneously. For example, in a network deployment simulation, 20 digital operation simulator instances can be run simultaneously, simulating the network access and communication processes of 20 different stations. The uplink signal from the digital operation simulator is a digital analog signal, transmitted to the communication satellite simulation module 130 through the network data interface of the unified data interface.

[0115] A semi-physical operating simulator connects a real baseband processing unit to a simulation loop. Baseband signals are processed by the real hardware, while the radio frequency (RF) band is replaced by digital-analog signals. The semi-physical operating simulator provides an intermediate level of simulation fidelity between the digital operating simulator and the RF operating simulator, suitable for verifying the correctness of baseband algorithms, signaling flows, and protocol implementations. For example, a real modem is connected to the simulation loop; the transmitting end generates baseband data using simulation software and modulates it using a real modulator; the receiving end demodulates the data using a real demodulator and returns it to the simulation software for error rate statistics. Baseband data from the semi-physical operating simulator is transmitted via a network data interface, and the baseband hardware and simulation software are connected through this interface.

[0116] RF Operation Simulator: Using real RF units and antenna equipment, it connects to the RF signal interface of the communication satellite simulation module 130 via an RF cable to generate realistic uplink and downlink RF signals. The RF operation simulator provides the highest fidelity simulation and is suitable for verifying RF link performance, equipment compatibility, and RF performance compliance. For example, using a real Ku-band RF unit to generate a 14.25GHz uplink RF signal, it is transmitted to the communication satellite simulation module 130 via an RF cable, and after transparent forwarding, outputs a 12.50GHz downlink RF signal, which is received and processed by the receiving RF unit. Control data from the RF operation simulator is transmitted via a network data interface, and RF signals are transmitted via an RF signal interface.

[0117] The three simulators are compared below: The digital operation simulator uses digital analog signals, has no real hardware connection, uses a network data interface, has low simulation fidelity, low deployment cost, and is suitable for large-scale network simulation and basic operation training; the hardware-in-the-loop (HIL) simulator uses a combination of baseband real signals and RF digital analog signals, connects to baseband hardware, uses a network data interface and a baseband data interface, has medium simulation fidelity, medium deployment cost, and is suitable for baseband algorithm verification and signaling process verification; the RF operation simulator uses real RF signals, connects to RF hardware and baseband hardware, uses an RF signal interface and a network data interface, has high simulation fidelity, high deployment cost, and is suitable for RF link performance verification and equipment compatibility verification.

[0118] Full-level simulation coverage means that the same station can select different levels of simulators according to the training objective, and different stations can use different levels of simulators simultaneously in the same training task.

[0119] For example, a training task may include five participating stations. GS-001 uses an RF operation simulator to verify RF link performance, GS-002 uses a hardware-in-the-loop (HIL) simulator to verify baseband signaling flow, and GS-003, AC-001, and AC-002 use digital operation simulators to support network simulation scale. The three simulators connect to the same simulation system via a unified data interface, sharing the same communication networking scheme and network control parameters. Signal interactions between stations are uniformly forwarded through the communication satellite simulation module 130, achieving hybrid-level joint simulation.

[0120] The uplink signal from the ground satellite service access station simulation module 140 is output to the communication satellite simulation module 130, while the downlink signal originates from the communication satellite simulation module 130. When using an RF operation simulator, the uplink signal is a real RF signal, transmitted via an RF cable to the RF signal interface of the communication satellite simulation module 130; when using a digital operation simulator, the uplink signal is a digital-analog signal, transmitted via a unified data interface network data interface to the communication satellite simulation module 130. The downlink works similarly.

[0121] The RF simulator of the Ground Satellite Service Access Station Simulation Module 140 adopts a plug-in modular design. This design divides the various functions of the RF simulator into independent standard plug-in modules based on their function type. These modules interconnect and exchange data via a unified backplane bus, and the front panel provides the external interface for RF signals and status information. This plug-in design gives the RF simulator excellent scalability and maintainability—when system capacity needs to be expanded, simply add the corresponding number of plug-in modules to the available slots on the backplane bus without modifying the configuration of other plug-in modules; when a plug-in module fails, it can be replaced individually without affecting the normal operation of other plug-in modules.

[0122] Standard card modules are classified into the following three categories according to their function: (1) Channel Terminal RF Simulator Card: Used to simulate the RF transceiver function of the channel terminal in the station equipment, including the generation of uplink RF signals and the reception of downlink RF signals. Each channel terminal RF simulator card corresponds to one channel terminal in one station and is configured with a transmit channel and a receive channel. The transmit channel generates uplink RF signals based on baseband data and modulation parameters, and the receive channel receives downlink RF signals and downconverts them to intermediate frequency (IF) output. For example, the transmit channel of the Ku-band channel terminal RF simulator card generates uplink RF signals in the 14.0 to 14.5 GHz band, and the receive channel receives downlink RF signals in the 12.25 to 12.75 GHz band and downconverts them to 140 MHz IF signals for output to the IF interface of the backplane bus.

[0123] (2) Inverter RF Simulator Card: Used to simulate the frequency conversion function of the inverter in the station-end equipment, including an up-converter and a down-converter. The up-converter converts the intermediate frequency signal from the backplane bus intermediate frequency interface into an uplink RF signal, which is then output to the RF cable via the front panel RF interface; the down-converter converts the downlink RF signal from the front panel RF interface into an intermediate frequency signal, which is then output to the intermediate frequency interface of the backplane bus. For example, the up-converter of the Ku-band inverter RF simulator card converts the 140MHz intermediate frequency signal into a 14.25GHz uplink RF signal, and the down-converter converts the 12.50GHz downlink RF signal into a 140MHz intermediate frequency signal.

[0124] (3) Combiner / Splitter RF simulator card: used to simulate the functions of power splitters and combiners in station-end equipment, and realize the synthesis and splitting of multiple RF signals. For example, the combiner / splitter RF simulator card combines three uplink RF signals of different frequencies into one signal and outputs it to the power amplifier, and splits one downlink RF signal into three signals and outputs them to three frequency converter RF simulator cards respectively.

[0125] Each plug-in module has a standardized intermediate frequency interface and a low frequency monitoring interface on its back panel.

[0126] The intermediate frequency (IF) interface is used to transmit IF signals on the backplane bus. It uses a standard IF connector (such as an SMA type interface) and the IF frequency is 140MHz (Ku band) or 70MHz (UHF band). Each plug-in module transmits IF signals on the backplane bus through the IF interface—for example, the channel terminal RF simulator plug-in card transmits the received 140MHz IF signal to the inverter RF simulator plug-in card for upconversion processing via the IF interface; the inverter RF simulator plug-in card transmits the downconverted 140MHz IF signal to the channel terminal RF simulator plug-in card for demodulation processing via the IF interface.

[0127] The low-frequency monitoring interface is used to exchange operational status data on the backplane bus. It employs a low-frequency signal connector (such as a DB9 interface) and transmits monitoring data including the online status, transmit power, receive level, gain value, and fault alarm information of each plug-in module. Each plug-in module reports its operational status data to the interface control and data management module 110 through the low-frequency monitoring interface and receives control commands (such as frequency configuration, power adjustment, and gain setting) from the interface control and data management module 110. For example, the channel terminal RF simulator plug-in card reports its current transmit power value (20dBW) and receive level value (-85dBm) through the low-frequency monitoring interface, while simultaneously receiving a control command from the interface control and data management module 110 to "adjust the transmit power to 22dBW".

[0128] The unified backplane bus serves as the physical channel for signal interconnection and data exchange between various plug-in modules. The backplane bus comprises two parts: an intermediate frequency (IF) signal transmission path and a low-frequency monitoring data transmission path. Each plug-in module is inserted into a standard slot on the backplane bus in parallel, achieving plug-and-play connection through the IF and low-frequency monitoring interfaces on the backplane. When system capacity needs to be expanded, simply add the corresponding number of plug-in modules and insert them into an empty slot on the backplane bus. The system automatically identifies the newly inserted plug-in modules and completes the configuration. For example, initially configured with two channel terminal RF simulator plug-in cards and one splitter / combiner RF simulator plug-in card, if a training task requires adding one more station, simply add one channel terminal RF simulator plug-in card and insert it into an empty slot on the backplane bus. The system automatically identifies the model and address of the newly inserted plug-in module through the low-frequency monitoring interface, completes the configuration, and is then ready for use.

[0129] Each card module has a status indicator light and an RF test interface on its front panel.

[0130] Status indicator lights are used to visually display the operating status of the card module, including a power indicator (green, solid on indicating normal power supply), a transmit indicator (red, flashing indicating RF signal transmission), a receive indicator (yellow, solid on indicating RF signal reception), and a fault indicator (red, flashing, indicating a fault alarm). For example, when the channel terminal RF simulator card is working normally, the power indicator is solid green, the transmit indicator is flashing red, and the receive indicator is solid yellow; when the power amplifier of the card module malfunctions, the fault indicator flashes red, and a fault alarm is reported to the interface control and data management module 110 via the low-frequency monitoring interface.

[0131] The RF test interface provides RF signal test points for external test instruments (such as spectrum analyzers and power meters) during debugging and maintenance, using standard RF connectors (such as N-type or SMA interfaces). For example, the front panel of a channel terminal RF simulator plug-in card is equipped with one transmit RF test interface and one receive RF test interface, used to test the spectrum and power of the uplink RF signal and the downlink RF signal, respectively. Debugging personnel can connect a spectrum analyzer through the RF test interface to monitor the RF signal quality of the plug-in card module in real time without disassembling the plug-in card module or connecting the instrument to the main signal link.

[0132] Each plug-in card module transmits radio frequency signals and network data bidirectionally with external devices via RF cables and Ethernet cables. RF signals are transmitted via the RF interface on the front panel, connected to the RF signal interface of the communication satellite simulation module 130 via an RF cable, transmitting uplink and downlink RF signals. Network data is transmitted via the low-frequency monitoring interface on the backplane bus, connected to the unified data interface of the interface control and data management module 110 via an Ethernet cable, transmitting control signaling and status data. For example, the front panel RF interface of the channel terminal RF simulator plug-in card is connected to the RF signal interface of the communication satellite simulation module 130 via an RF cable. Uplink RF signals are transmitted to the communication satellite simulation module 130 via the RF cable for transparent forwarding, while downlink RF signals are returned from the communication satellite simulation module 130 to the plug-in card module via the RF cable. Simultaneously, the plug-in card module is connected to the interface control and data management module 110 via the low-frequency monitoring interface and Ethernet cable on the backplane bus, reporting operational status data in real time and receiving control commands.

[0133] The airborne satellite communication terminal simulation module 150 is used to simulate Ku-band and UHF-band satellite communication terminal equipment on an airborne platform. The terminal equipment simulated by the airborne satellite communication terminal simulation module 150 includes an antenna unit, a radio frequency unit, a baseband processing unit, a voice encoding / decoding unit, and a message processing unit.

[0134] The antenna element simulates the antenna characteristics and tracking behavior of the airborne platform. Due to the platform's positional movement and attitude changes during flight, the antenna needs to adjust its pointing in real time to track the satellite. During the simulation, the antenna pointing angle is calculated based on preset flight trajectory parameters (including airspeed, heading, and altitude), and the corresponding Doppler shift effect is simulated. For example, when the airborne platform flies at 800 km / h, the Doppler shift generated in the Ku band (carrier frequency 14 GHz) is approximately 10.4 kHz; this shift is applied to the radio frequency signal during the simulation.

[0135] The radio frequency unit simulates the uplink radio frequency signal generation and downlink radio frequency signal reception of the airborne terminal. The uplink frequency of the Ku-band terminal is 14.0-14.5GHz, and the downlink frequency is 12.25-12.75GHz; the uplink frequency of the UHF-band terminal is 300-318MHz, and the downlink frequency is 248-270MHz.

[0136] The baseband processing unit performs analog signal modulation and demodulation, channel encoding and decoding, and framing and deframing. Modulation methods include QPSK and 8PSK, and encoding methods include convolutional codes and LDPC codes. For example, Ku-band airborne terminals use QPSK modulation and LDPC encoding, with an information rate of 2 Mbps; UHF-band airborne terminals use QPSK modulation and convolutional code encoding, with an information rate of 64 kbps.

[0137] The voice codec unit processes analog voice signals using either the G.711 or G.729 codec standard. The analog voice signals are converted into digital voice frames and transmitted via satellite link. The G.711 standard has a coding rate of 64 kbps, while the G.729 standard has a coding rate of 8 kbps.

[0138] The message processing unit simulates the encapsulation, transmission, and acknowledgment of short messages. Short messages use a structured data format, including a message header and a message body. The message header contains source address, destination address, message type, and sequence number fields; the message body carries the message content. A retransmission acknowledgment mechanism is supported during transmission—after the sender sends the short message, a timer is started. If an acknowledgment message is received from the receiver before the timer expires, the transmission is considered successful; otherwise, the short message is retransmitted.

[0139] The airborne satellite communication terminal simulation module 150 supports voice communication simulation between the airborne terminal and the ground satellite service access station simulation module 140 via the communication satellite simulation module 130.

[0140] The voice communication simulation process is as follows: The transmitting end (airborne terminal or ground station) acquires voice signals, which are encoded by the voice codec unit according to the G.711 standard (coding rate 64kbps) to generate voice digital frames; the voice digital frames are channel coded and modulated by the baseband processing unit, and then upconverted into uplink radio frequency signals by the radio frequency unit and transmitted; the uplink radio frequency signals are transparently forwarded by the communication satellite simulation module 130 and then converted into downlink radio frequency signals to reach the receiving end; the radio frequency unit of the receiving end receives the downlink radio frequency signals, demodulates and decodes them by the baseband processing unit to recover the voice digital frames, and then decodes them into voice signals by the voice codec unit for output.

[0141] During the simulation, the communication satellite simulation module 130 applies transmission impairments to the relay signal based on channel environment parameters. The demodulated signal at the receiving end contains corresponding bit errors and fading effects, thus realistically reflecting the transmission characteristics of the satellite communication link. For example, when the rain attenuation in the channel environment parameters is 8dB, the signal level at the receiving end decreases by 8dB accordingly. When the signal level falls below the demodulation threshold, voice communication is interrupted, and the user needs to restore communication by adjusting the transmit power or switching to a backup link.

[0142] The airborne satellite communication terminal simulation module 150 supports the simulation of short message data transmission between the airborne terminal and the ground satellite service access station simulation module 140 via the communication satellite simulation module 130.

[0143] The simulation process for short message data transmission is as follows: The message processing unit at the sending end encapsulates the message content to be sent into a short message data frame, including a message header (source address, destination address, message type, and sequence number) and a message body (message content); after the short message data frame is channel-coded and modulated by the baseband processing unit, it is up-converted into an uplink radio frequency signal by the radio frequency unit and transmitted; the uplink radio frequency signal is transparently forwarded by the communication satellite simulation module 130 and arrives at the receiving end; the receiving end receives the short message data frame through the radio frequency unit, demodulates and decodes it through the baseband processing unit, and then recovers the short message data frame. The message processing unit parses the message header and message body, outputs the message content to the display interface, and simultaneously returns an acknowledgment message to the sending end.

[0144] For example, the airborne terminal AC-001 sends a short message "Request to establish voice communication" to the ground station GS-001. The message processing unit encapsulates the message content into a short message data frame with the source address AC-001, the destination address GS-001, the message type "TEXT", and the sequence number 0001. After the data frame is transmitted to GS-001 via the Ku-band radio frequency link, the message processing unit of GS-001 parses and displays the message content, and simultaneously returns an acknowledgment message (source address GS-001, destination address AC-001, message type "ACK", sequence number 0001). If AC-001 does not receive the acknowledgment message before the timer expires, it retransmits the short message.

[0145] like Figure 2 As shown, a second aspect of this application provides a control method for a satellite communication simulation system, applied to the satellite communication simulation system of the first aspect embodiment described above, comprising: S1, the interface control and data management module loads the preset training task scenario file, parses the list of training stations, communication networking scheme and performance evaluation parameters in the training task scenario file, generates training task instances and assigns a unique training task number. S2. The satellite network control center simulation module configures network control parameters for the ground satellite service access station simulation module and the airborne satellite communication terminal simulation module according to the network topology in the communication networking scheme. The network control parameters include communication subnet identifier, transponder frequency resources, control channel parameters and channel unit address. The network control parameters are then sent to the corresponding ground satellite service access station simulation module and airborne satellite communication terminal simulation module through a unified data interface. S3. After receiving the network control parameters, the ground satellite service access station simulation module and the airborne satellite communication terminal simulation module automatically execute the equipment initialization process. According to the FDMA or TDMA network access protocol corresponding to the configured network control parameters, they initiate a network access request to the satellite network control center simulation module. The satellite network control center simulation module performs access authentication based on the channel unit address and user number in the network access request. After successful authentication, a communication link is established and a network access confirmation message is sent back. S4. During network communication, the interface control and data management module injects fault parameters or channel environment parameters into the designated simulation module according to the preset abnormal situation handling plan or guidance control command, simulates equipment failure or channel degradation scenarios, and records the handling operation sequence and operation time input by the user through each simulation module. S5. After training, the interface control and data management module collects operation logs and running status data throughout the process. According to the corresponding scoring rules and weights in the performance evaluation parameters, it performs quantitative scoring from three evaluation dimensions: operation standardization, network timeliness, and fault handling capability, and generates a training evaluation report.

[0146] The following example, a complete training task, illustrates the collaborative workflow of the various modules in the system.

[0147] The task planning submodule of the interface control and data management module loads the preset training task scenario file, parses out 5 training station terminals (GS-001 stationary vehicle-mounted station, GS-002 box-type station, GS-003 mobile vehicle-mounted station, AC-001 airborne Ku terminal, AC-002 airborne UHF terminal), 2 sets of communication subnets (subnet 1 is a Ku-band FDMA system including GS-001 / GS-002 / AC-001, subnet 2 is a UHF-band TDMA system including GS-003 / AC-002) and performance evaluation parameters (operational standardization weight 0.4, network timeliness weight 0.3, fault handling capability weight 0.3, preset standard time consumption 300 seconds), generates a training task instance and assigns the task number TASK-20260812-001, and writes the above data into the shared data pool.

[0148] The satellite network control center simulation module reads the communication networking scheme from the shared data pool, configures the uplink carrier frequency (14.25GHz for GS-001, 14.30GHz for GS-002, and 14.35GHz for AC-001) and channel unit address for each station in subnet 1, configures the time slot allocation (time slots 1-2 for GS-003 and 3-4 for AC-002), and sends the network control parameters to the simulation modules of each station through a unified data interface.

[0149] After receiving the network control parameters, each station's simulation module completes equipment initialization. GS-001, GS-002, and AC-001 send network access request messages on the control ALOHA channel according to the FDMA network access protocol. The satellite network control center's simulation module queries the authentication table to verify the validity, then sends a network access confirmation response and allocates channel resources. GS-003 and AC-002 initiate network access requests according to the TDMA network access protocol, and time slots are allocated after verification. After all five stations complete network access, network establishment and link construction are complete.

[0150] Each station communicates via a satellite communication simulation module for voice and short message data transmission. For example, a Ku-band voice communication link is established between GS-001 and AC-001, with the voice signal encoded in G.711 and transmitted via satellite; short message data is transmitted between GS-003 and AC-002 via the UHF band. The interface control and data management module polls and collects the operating status data of each simulation module every 1 second and writes it to the shared data pool.

[0151] During training, the interface control and data management module injects a fault parameter of "power amplifier gain drop of 20dB" into the GS-001 according to the preset abnormal situation handling plan, simulating a device failure scenario. The user performs troubleshooting and handling operations through the GS-001's user interface. The abnormal situation handling submodule records the user's handling operation sequence and operation time, and writes it to the shared data pool.

[0152] After training, the performance evaluation submodule of the interface control and data management module reads operational status data, operation logs, and performance evaluation parameters from the shared data pool. The calculated scores are: operational standardization score of 85 (90% step consistency rate, 80% sequence correctness rate); network deployment timeliness score of 90 (total time 270 seconds, lower than the preset standard of 300 seconds); and fault handling capability score of 75 (location time 45 seconds, correct handling plan). The weighted average score is: 85×0.4 + 90×0.3 + 75×0.3 = 83.5 points. The evaluation results are presented in the form of a radar chart and a quantitative scoring table. The three axes of the radar chart correspond to operational standardization, network deployment timeliness, and fault handling capability, respectively. The quantitative scoring table lists the scores for each dimension and the overall score of 83.5 points.

[0153] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A satellite communication simulation system, characterized in that, It includes an interface control and data management module, a satellite network control center simulation module, a communication satellite simulation module, a ground satellite service access station simulation module, and an airborne satellite communication terminal simulation module; The interface control and data management module is used to construct training task scenarios and generate communication networking schemes, issue guidance and control commands and collect the running status data of each simulation module. It communicates with each simulation module through a unified data interface and supports centralized scheduling of task planning, network training, abnormal situation handling and performance evaluation. Its functional sub-modules are synchronized in real time through a shared data pool. The satellite network control center simulation module is used to simulate network management and station control functions. Based on the communication networking scheme, it generates network control parameters for the FDMA and TDMA integrated service network and sends them to the ground satellite service access station simulation module and the airborne satellite communication terminal simulation module. It supports communication subnet configuration, channel resource allocation, network entry and exit signaling interaction simulation, and parallel management and control of multiple communication subnets. The communication satellite simulation module is used to simulate transparent forwarding function. It receives uplink radio frequency signals or digital analog signals, and generates downlink signals after low-noise amplification, downconversion, intermediate frequency filtering and upconversion processing. It supports Ku and UHF band forwarding simulation and dynamic updating of channel environment parameters. The ground satellite service access station simulation module is used to simulate stationary satellite communication vehicle-mounted stations, box-type stations, and mobile satellite communication vehicle-mounted stations. It achieves full-level simulation coverage through radio frequency, semi-physical, and digital operation simulators. Its uplink signal is output to the communication satellite simulation module, and the downlink signal comes from the communication satellite simulation module. The airborne satellite communication terminal simulation module is used to simulate airborne platform Ku and UHF band satellite communication terminal equipment, and supports the simulation of voice communication and short message data transmission between the airborne terminal and the ground satellite service access station simulation module via the communication satellite simulation module.

2. The satellite communication simulation system according to claim 1, characterized in that, The communication satellite simulation module achieves dynamic updating of channel environment parameters through a channel environment simulation unit. The channel environment simulation unit establishes a unified radio frequency signal interface and network data interface with the external channel and environment simulation equipment, and receives the channel environment parameters injected by the external channel and environment simulation equipment. The channel environment parameters include multipath fading model parameters, rain attenuation parameters, Doppler frequency shift parameters, and co-channel interference signal parameters. The communication satellite simulation module determines the radio frequency domain transmission impairment and the baseband domain transmission impairment based on the channel environment parameters, applies the radio frequency domain transmission impairment to the radio frequency analog link, and applies the baseband domain transmission impairment to the digital analog link, so that the transmission impairment of the radio frequency analog link and the digital analog link are updated synchronously.

3. The satellite communication simulation system according to claim 1, characterized in that, The interface control and data management module also includes a training and evaluation docking unit. The training and evaluation docking unit establishes a standardized data exchange interface with the external evaluation system and receives task plan files, directing and control instructions and task role configuration information through the data exchange interface. The training and evaluation docking unit reads the communication link operation data, channel resource usage data, and operation status data of each simulation module from the shared data pool, generates performance evaluation indicators based on the read data, reports the performance evaluation indicators to the external evaluation system through the data exchange interface, and writes the performance evaluation indicators into the shared data pool for synchronous use by each functional sub-module.

4. The satellite communication simulation system according to claim 1, characterized in that, The networking training submodule of the interface control and data management module adopts a scenario-driven training organization method, which automatically generates communication subnetwork parameter configuration, channel resource allocation scheme and ground satellite service access station network access sequence based on the pre-stored communication networking scenario file; The network training submodule distributes the generated configuration parameters to the satellite network control center simulation module, the ground satellite service access station simulation module, and the airborne satellite communication terminal simulation module through a unified data interface. After receiving the configuration parameters, each simulation module completes the device initialization process and the network connection establishment process. After the network is established, the interface control and data management module obtains the operating status data and link quality indicators of each simulation module through a polling acquisition mechanism, evaluates the network effect based on preset scoring rules, and displays the evaluation results in the form of radar charts and quantitative scoring tables.

5. The satellite communication simulation system according to claim 1, characterized in that, The satellite network control center simulation module generates network control parameters for the FDMA integrated service network and the TDMA integrated service network using a parametric simulation configuration method, and pre-establishes a satellite transponder parameter library, a beam coverage model library, and a channel template library. During the simulation operation, the satellite network control center simulation module automatically matches the corresponding transponder parameters, beam coverage range, and channel template parameters from the satellite transponder parameter library, beam coverage model library, and channel template library according to the communication networking scheme provided by the task planning submodule of the interface control and data management module. Based on the matching results, the satellite network control center simulation module calculates the uplink effective omnidirectional radiated power of each ground satellite service access station using the following formula. : ； in, The uplink effective omnidirectional radiated power of the ground satellite service access station; Antenna transmit gain; This refers to the feeder insertion loss; The transmitter output power is expressed in decibels.

6. The satellite communication simulation system according to claim 1, characterized in that, The Ku-band forwarding RF simulator of the communication satellite simulation module adopts a single-conversion architecture to achieve transparent forwarding processing of uplink RF signals to downlink RF signals. The Ku-band forwarding RF simulator receives the uplink Ku-band RF signal, which is then amplified by a low-noise amplifier, converted to an intermediate frequency signal by a downconverter, filtered by an intermediate frequency, adjusted by automatic gain control, and converted to a downlink Ku-band RF signal by an upconverter before being amplified and output by a power amplifier. The local oscillator signals of the up-converter and the down-converter are provided by a common local oscillator phase-locked loop frequency synthesizer; The overall gain and noise figure of the Ku-band relay RF simulator are calibrated according to the model parameters of the communication satellite being simulated.

7. The satellite communication simulation system according to claim 1, characterized in that, The radio frequency simulator of the ground satellite service access station simulation module adopts a plug-in modular design, which divides the channel terminal radio frequency simulator, frequency converter radio frequency simulator and splitter / combiner radio frequency simulator of different frequency bands into independent standard plug-in modules according to their functional types. Each plug-in module has a standardized intermediate frequency interface and a low frequency monitoring interface on its backplane side. Each plug-in module transmits intermediate frequency signals through the intermediate frequency interface on the unified backplane bus and exchanges operating status data through the low frequency monitoring interface. Each card module has a status indicator light and an RF test interface on its front panel, and can transmit RF signals and network data bidirectionally with external devices via RF cables and Ethernet cables.

8. A control method for a satellite communication simulation system, applied to the satellite communication simulation system according to any one of claims 1 to 7, characterized in that, include: S1. The interface control and data management module loads the preset training task scenario file, parses the list of training stations, communication networking scheme and performance evaluation parameters in the training task scenario file, generates training task instances and assigns unique training task numbers. S2. The satellite network control center simulation module configures network control parameters for the ground satellite service access station simulation module and the airborne satellite communication terminal simulation module according to the network topology in the communication networking scheme. The network control parameters include communication subnet identifier, transponder frequency resources, control channel parameters and channel unit address. The network control parameters are then sent to the corresponding ground satellite service access station simulation module and airborne satellite communication terminal simulation module through a unified data interface. S3. After receiving the network control parameters, the ground satellite service access station simulation module and the airborne satellite communication terminal simulation module automatically execute the equipment initialization process and initiate a network access request to the satellite network control center simulation module according to the FDMA or TDMA network access protocol corresponding to the configured network control parameters. The satellite network control center simulation module performs access authentication based on the channel unit address and user number in the network access request. After successful authentication, a communication link is established and a network access confirmation message is sent back. S4. During network communication, the interface control and data management module injects fault parameters or channel environment parameters into the designated simulation module according to the preset abnormal situation handling plan or guidance control command, simulates equipment failure or channel degradation scenarios, and records the handling operation sequence and operation time input by the user through each simulation module. S5. After training, the interface control and data management module collects the operation logs and running status data of the entire process, and performs quantitative scoring from three evaluation dimensions—operation standardization, networking timeliness, and fault handling capability—according to the scoring rules and weights in the performance evaluation parameters, and generates a training evaluation report.

9. The control method for the satellite communication simulation system according to claim 8, characterized in that, The access authentication process of the FDMA network access protocol in step S3 includes: The ground satellite service access station simulation module sends a network access request message in a contention-based manner on the control ALOHA channel configured in the network control parameters. The network access request message includes the channel unit address, user number, and requested service type of the ground satellite service access station simulation module. After receiving the network access request message, the satellite network control center simulation module queries a preset authentication table to verify the legality of the channel unit address and the user number. Upon successful verification, the satellite network control center simulation module sends a network access confirmation response to the ground satellite service access station simulation module on the TDM broadcast channel and marks the channel unit status of the ground satellite service access station simulation module as online. If the verification fails, the satellite network control center simulation module sends a network access rejection response message on the TDM broadcast channel, the network access rejection response message including the corresponding rejection reason code.

10. The control method for the satellite communication simulation system according to claim 8, characterized in that, In step S5, the operation standardization score is calculated based on the consistency rate and sequence correctness between the actual operation steps of the user and the standard operation procedure template; the network timeliness score is calculated based on the ratio of the total time from the issuance of the network command to the completion of network access for all participating stations to the preset standard time in the performance evaluation parameters. The fault handling capability score is calculated based on the location time and correctness of the fault handling plan of the operator. The three evaluation dimensions are weighted and averaged according to the weights in the performance evaluation parameters to obtain the final evaluation result of the operator.

Images