A satellite service plan-based mega constellation terminal access method

Abstract

The application provides a kind of based on satellite service plan Mega constellation terminal access method, method includes: step 1: terminal initialization;Step 2: service satellite selection: according to satellite service plan setting, terminal own position and time information, search serviceable satellite, form to be captured service satellite queue;The selection of service satellite is based on terminal time;Step 3: determine acquisition parameter: from the order of to-be-acquired service satellite queue serviceable satellite, calculate signal Doppler, determine terminal antenna pointing, frequency search range and acquisition parameter in acquisition threshold;Step 4: signal acquisition control: according to the calculated terminal antenna pointing and signal parameter adjustment antenna pointing and channel, satellite signal acquisition is carried out;Step 5: system parameter acquisition: step 6: uplink signal access: step 7: plan online update.The application forms the access process framework based on satellite service plan Mega constellation.

Description

Technical Field

[0001] This application relates to the field of satellite communication system access technology, and in particular to a method for accessing a giant constellation terminal based on a satellite service plan. Background Technology

[0002] With the construction and operation of systems such as OneWeb and Starlink, satellite communication systems have entered the era of mega-constellations characterized by large-scale satellites, high link frequencies, and antenna gain. The number of system satellites has expanded from dozens to tens of thousands, and the traditional "coverage-first, best-effort" design philosophy of satellite communication systems has been advanced to "broadband design, service-first" compatible with terrestrial mobile communication systems. Satellite communication systems have become an important component of 5G and 5G-Beyond, supporting seamless global communication coverage and achieving integrated development with terrestrial mobile communication systems. Traditional constellation satellite communication systems, represented by Iridium and Globalstar, are mainly geared towards terrestrial mobile services, characterized by multi-color multiplexing and weak antenna direction-of-flight terminals. Their access process is basically the same as that of terrestrial mobile communication systems, achieving system access through direct search of satellite signals.

[0003] However, giant constellation communication systems employ beam agility and high communication frequency bands, and both terminals and satellites have strong directionality. At the same time, the satellite-to-ground link has strong timeliness. If traditional satellite signal search methods are used, the airspace search under the multiple coverage of the giant constellation will greatly extend the time for terminals to access the system and reduce system efficiency. Therefore, it is necessary to focus on researching efficient access methods for terminals.

[0004] Currently, research on mega-constellation communication systems mainly focuses on the architecture of space-ground integration. Efficient access remains an open question with no relevant research. It is necessary to combine the system's working mechanism to optimize the terminal access process and improve the efficiency of terminal access to the system. Summary of the Invention

[0005] This application provides a method for terminal access to a giant constellation based on a satellite service plan, which can be used to solve the technical problem of lack of efficient access in giant constellation communication systems.

[0006] This application provides a method for giant constellation terminal access based on a satellite service plan, the method including:

[0007] Step 1: Terminal initialization;

[0008] Step 2: Selecting a Service Satellite

[0009] Based on the satellite service plan settings, the terminal's own location and time information, available satellites are searched to form a queue of service satellites to be acquired {STi}; the selection of service satellites is based on the terminal time.

[0010] Step 3: Determine the capture parameters:

[0011] Extract available satellites sequentially from the queue of service satellites to be acquired {STi}, calculate the signal Doppler, and determine the acquisition parameters, including the terminal antenna pointing, frequency search range, and acquisition threshold.

[0012] Step 4: Signal Acquisition Control

[0013] Adjust the antenna pointing and channel according to the calculated terminal antenna pointing and signal parameters to acquire satellite signals;

[0014] Step 5: Obtain system parameters:

[0015] It receives captured satellite user link downlink signals, parses frame content according to frame format, and obtains system information, ephemeris information, and uplink parameter information based on system settings.

[0016] Step 6: Uplink signal access:

[0017] The satellite position is calculated based on the acquired ephemeris information. Combined with the terminal position information and uplink frequency parameters, the satellite-to-ground propagation delay and uplink signal Doppler are calculated. Based on the random access time slot specified by the system information, the uplink signal is transmitted and the system is accessed.

[0018] Step 7: Online update of the contingency plan:

[0019] After the terminal connects to the system, it actively acquires or monitors satellite service plan broadcast messages, receives all or part of the service satellite plan broadcast by the system, updates the local satellite service plan, and ensures the efficiency of terminal access to the system.

[0020] Further, step 1: terminal initialization, includes:

[0021] The software is loaded, and then the satellite navigation module is used to obtain the terminal's own location information PTi and time information TTi.

[0022] For fixed-location terminals, location information can be obtained through pre-configuration, and time information is maintained using a timekeeping module.

[0023] Further, step 2: service satellite selection, including:

[0024] Step 21: The terminal retrieves the ground service area identifier (PSTI) of its location from the pre-stored satellite service plan based on its own location information (PTi).

[0025] Step 22: Using the terminal time information as the reference TTi, the available satellites for the current time period are searched in the satellite service plan pre-loaded on the terminal using the ground service area identifier PSTi where the terminal is located.

[0026] Step 23: According to the rules set in the satellite service plan, sort the service satellites in the ground service area where the terminal is located as given in the satellite service plan to form a queue of service satellites to be captured {STi}. At the same time, start the total capture timer Ta.

[0027] Furthermore, the satellite service plan clarifies the set of satellites available for service in different ground service areas at different times. The plan supports multi-satellite service planning for ground service areas and assigns weights to the service satellites to optimize terminal acquisition order. The content includes:

[0028] Table 1: Satellite Service Contingency Plan

[0029]

[0030] Ground service area information includes ground service area settings and calculation algorithms, used to determine the ground service area where the computing terminal is located;

[0031] Constellation satellite information includes constellation configuration and satellite parameters, used to indicate the satellite's on-orbit status and calculate the satellite's real-time position;

[0032] System access control includes terminal access policies and basic parameters of the contingency plan, which are used to guide the terminal in acquisition control;

[0033] The terminal acquisition parameters are calculated to describe the satellite service planning and acquisition priority, and to provide the available satellite identifiers for different ground service areas during different access time periods.

[0034] Furthermore, the strategies of the satellite service contingency plan include the following methods:

[0035] Strategy 21: Network Access Registration Update: Used for terminal network access registration, it requires specifying the terminal's serviceable area and writing in the complete satellite service plan data agreed upon by the system;

[0036] Strategy 22: Manual contingency plan update: Update the contingency plan through the Internet, 5G network or other means, using media such as USB flash drive, CD or direct network connection for updates, applicable to updates before restarting after a long shutdown or after equipment failure;

[0037] Strategy 23: Automatic Terminal Update: After the terminal connects to the system, it updates some or all entries of the satellite service plan based on the satellite service plan time stored in the terminal.

[0038] Further, step 3: Determine the capture parameters, including:

[0039] Step 31: Based on the terminal's local time TTi, obtain the available satellites STi in order from the queue of service satellites to be captured {STi};

[0040] Step 32: Use the extracted service satellite STi identifier to find its ephemeris in the satellite service plan, and calculate the current position and motion vector of the satellite based on the terminal local time TTi and the found satellite ephemeris;

[0041] Step 33: Combine the terminal location information and the satellite location information to calculate the elevation and azimuth of the terminal antenna, as well as the satellite-to-ground link loss. Based on the satellite motion vector information and the system downlink signal frequency, calculate the signal Doppler and the terminal antenna pointing direction. Use the signal Doppler to determine the acquisition parameters, including the frequency search range and acquisition threshold.

[0042] Further, step 4: signal acquisition control, includes:

[0043] Step 41, Signal Acquisition: Based on the acquisition parameters, control the terminal to acquire satellite signals and simultaneously start the single acquisition timer Ts;

[0044] Step 42, jump control: If the acquisition is successful, the signal is received and the process proceeds to step 5; if the single acquisition timer Ts completes, the process checks whether there are any new serviceable satellites in the queue of service satellites to be acquired {STi}. If there are serviceable satellites STi, the process jumps to step 3 to calculate the acquisition parameters and re-acquire the signal; otherwise, the process jumps to step 4.3.

[0045] Step 43, orbital plane search: Referring to the satellite ephemeris given in the plan, calculate the possible orbital position deviation of the satellite according to the satellite ephemeris time deviation probability model, generate virtual orbital position, reconstruct the service satellite search set, generate virtual ephemeris, jump to step 32, calculate the capture parameters, and re-initiate the capture.

[0046] Step 44, Error Reporting: If the total capture timer Ta completes, stop signal capture and report an access error.

[0047] Furthermore, the methods for updating the contingency plan online include:

[0048] Broadcast data update: The terminal receives ephemeris information and other data broadcast by the system and updates the corresponding data in the satellite service plan;

[0049] Application for Update: The terminal can proactively request a full or partial update, supporting individual updates to satellite identifiers, ephemeris, and service satellite plans.

[0050] This application innovatively proposes a mega-constellation access process based on satellite service contingency plans, which solves the problems of uncertainty in satellite services caused by the high coverage of satellites under mega-constellations and the poor system access time caused by the uncertainty of the terminal's perception of the satellite position before accessing the system, thus forming a framework for mega-constellation access process based on satellite service contingency plans.

[0051] This application innovatively proposes an orbital plane virtual satellite search scheme, which avoids the system blind search problem caused by inaccurate satellite ephemeris in the contingency plan. It uses satellite virtual position calculation under orbital plane constraints to guide satellite signal acquisition, compresses the search space, and achieves efficient acquisition of satellite signals.

[0052] This application takes into account the scale of different constellation satellites, and through qualitative search of pre-set service satellites, effectively compresses the spatial search space of satellite signals, greatly shortens the signal acquisition time, and improves the timeliness of terminal access to the giant constellation communication system.

[0053] For terminal access scenarios where satellite service plans have not been updated for a long time, an orbital plane virtual satellite search scheme is adopted to search for satellite signals, which reduces the blind search space for satellite signals under satellite ephemeris deviation and enables rapid acquisition of constellation satellite signals. Attached Figure Description

[0054] Figure 1 A schematic diagram of a giant constellation system service provided in an embodiment of this application;

[0055] Figure 2 A flowchart illustrating the solution provided in this application's embodiments;

[0056] Figure 3 Example diagram of satellite service plan provided in the embodiments of this application;

[0057] Figure 4 This is a schematic diagram illustrating the classification of proposed solutions for embodiments of this application.

[0058] Figure 5 This is a schematic diagram of the signal acquisition control process provided in an embodiment of this application;

[0059] Figure 6 The terminal antenna pattern provided in the embodiments of this application;

[0060] Figure 7 A schematic diagram of capture performance provided for an embodiment of this application;

[0061] Figure 8 This is a schematic diagram of the application plan update process provided in this embodiment. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0063] Unlike traditional satellite communication systems, the large-scale satellite constellation system significantly increases the number of satellite coverage layers for the same ground service area, sometimes reaching dozens or even hundreds. The system must coordinate multiple satellites to select a limited number to serve the ground service area. This satellite selection method alters the shortest-distance service principle of traditional constellation systems, preventing terminals from directly obtaining available satellites through satellite-to-ground position calculations. Furthermore, to circumvent the frequency coordination challenges introduced by high coverage layers, giant constellation systems typically employ agile beamforming to serve ground terminals. This lacks the signaling signal support for satellite search typical of terrestrial mobile communication systems, necessitating improvements to traditional blind signaling signal acquisition satellite access strategies to meet the uncertain access requirements of giant constellation service satellites. Additionally, the short coverage time and multi-satellite relay service of low-Earth orbit (LEO) satellites do not allow for prolonged stationary acquisition of specific satellite signals. Therefore, a completely new terminal access process needs to be designed to adapt to the uncertainty of service satellites introduced by the multiple coverage layers of giant constellations, overcome the short coverage time of LEO satellites and the bursty signal characteristics of service areas introduced by high-frequency, high-gain bands, and achieve efficient terminal access to the system.

[0064] A comprehensive analysis of the current system architecture and technological development, Figure 1 A schematic diagram of a mega-constellation system characterized by a large satellite base and multiple satellite coverage layers is presented. The constellation satellites provide high-layer coverage to the ground, typically exceeding four layers, and employ a beam-hopping mechanism to provide access services to ground service areas. The mega-constellation system uses ground service areas for satellite selection and scheduling, supporting multiple satellites simultaneously providing access services to the same ground service area. User terminals can obtain their accurate location information and, using phased array antennas, possess the ability to adjust beam direction to access specific satellites.

[0065] Similar to traditional satellite communication systems, the user terminal first captures the downlink signal of the constellation satellite user link, then decodes it to obtain the uplink signal parameters, system information and ephemeris information of the satellite user link, then corrects the user link signal transmission time reference, and transmits the user link uplink signal in the designated time slot to access the access system.

[0066] Based on the system and terminal model analysis, considering the uncertainty of satellite position, the terminal needs to search for satellite signals in the entire airspace. Although the agility of phased array beams can support rapid airspace search, the uncertainty in the airspace greatly increases the signal search time. Therefore, satellite position is the key to reducing satellite signal search time.

[0067] Therefore, this application provides a terminal access method based on a satellite service plan. This method calculates satellite positions based on a pre-set satellite service plan, reduces the spatial uncertainty of terminal search, and effectively improves the timeliness of terminal access system.

[0068] The contingency plan provides precise parameters for the service satellites, and the specific technical steps to resolve the problem are as follows:

[0069] Step 1: Terminal initialization, acquiring its own location and time information; Step 2: Based on the parameters, the terminal selects the system's preset serviceable satellites to form an acquisition queue; Step 3: Combining the terminal's location information, the terminal calculates the antenna pointing and other signal parameters to acquire signals; Step 4: Adjusts the antenna pointing and acquires signals according to the acquisition parameters; Step 5: Acquires and receives downlink signals, extracting system information, ephemeris information, parameter information, etc.; Step 6: Calculates correction parameters based on the received information, transmits uplink signals, and accesses the system; Step 7: Actively acquires or monitors service satellite plan broadcast messages and updates the local satellite service plan.

[0070] Combined with appendix Figure 2 The method provided in this application includes the following steps:

[0071] Step 1: Terminal initialization;

[0072] After the terminal is powered on, it first loads the software, and then uses the satellite navigation module to obtain the terminal's own location information PTi and time information TTi.

[0073] For fixed-location terminals, location information can be obtained through pre-configuration, and time information is maintained using a timekeeping module.

[0074] Step 2: Selecting Service Satellites

[0075] Based on the satellite service plan settings, the terminal's own location and time information, available satellites are searched to form a queue of service satellites to be captured {STi}.

[0076] Due to the high-speed movement of satellites relative to the ground, the selection of service satellites is based on the terminal time, and the specific process is as follows:

[0077] Step 21: The terminal retrieves the ground service area identifier PSTi of its location from the pre-stored plan based on its own location information PTi.

[0078] Step 22: Using the terminal time information as the reference TTi, the available satellites for the current time period are searched in the satellite service plan pre-loaded on the terminal using the ground service area identifier PSTi where the terminal is located.

[0079] Step 23: According to the rules set in the satellite service plan, sort the service satellites in the ground service area where the terminal is located as given in the satellite service plan to form a queue of service satellites to be captured {STi}. At the same time, start the total capture timer Ta.

[0080] The satellite service plan clearly defines the set of satellites available for service in different ground service areas at different times. The plan supports multi-satellite service planning for ground service areas and assigns weights to the service satellites, optimizing terminal acquisition and sorting. It can accurately guide terminals to access the system, such as... Figure 3 As shown, the content includes, but is not limited to, the following items:

[0081] Table 1: Satellite Service Contingency Plan

[0082]

[0083] Among them, the ground service area information includes the ground service area settings and calculation algorithms, which are used to calculate the ground service area where the terminal is located;

[0084] Constellation satellite information includes constellation configuration and satellite parameters, used to indicate the satellite's on-orbit status and calculate the satellite's real-time position;

[0085] System access control includes terminal access policies and basic parameters of the contingency plan, which are used to guide the terminal in acquisition control;

[0086] The terminal acquisition parameters are calculated to describe the satellite service planning and acquisition priority, and to provide the available satellite identifiers for different ground service areas during different access time periods.

[0087] Satellite service plans are time-sensitive and require timely updates to ensure that the data in the plan can effectively support satellite retrieval and search, and to avoid reduced system signal acquisition efficiency due to information discrepancies. Strategies for updating the plan include, but are not limited to, the following:

[0088] Strategy 21: Network Access Registration Update: Used for terminal network access registration, it requires specifying the terminal's serviceable area and writing in the complete satellite service plan data agreed upon by the system;

[0089] Strategy 22: Manual contingency plan update: Update the contingency plan through the Internet, 5G network or other means, using media such as USB flash drive, CD or direct network connection for updates, applicable to updates before restarting after a long shutdown or after equipment failure;

[0090] Strategy 23: Automatic Terminal Update: After the terminal connects to the system, it updates some or all entries of the satellite service plan based on the satellite service plan time stored in the terminal.

[0091] Figure 4 The update method and operation of the satellite service plan are given.

[0092] Step 3: Determine the capture parameters:

[0093] Servicable satellites are extracted sequentially from the queue of service satellites to be acquired {STi}, signal Doppler is calculated, and acquisition parameters, including terminal antenna pointing, frequency search range, and acquisition threshold, are determined.

[0094] The specific steps for calculating the capture parameters are as follows:

[0095] Step 31: Based on the terminal's local time TTi, obtain the available satellites STi in order from the queue of service satellites to be captured {STi};

[0096] Step 32: Use the extracted service satellite STi identifier to find its ephemeris in the satellite service plan, and calculate the current position and motion vector of the satellite based on the terminal local time TTi and the found satellite ephemeris;

[0097] Step 33: Combine the terminal location information and the satellite location information to calculate the elevation and azimuth of the terminal antenna, as well as the satellite-to-ground link loss. Based on the satellite motion vector information and the system downlink signal frequency, calculate the signal Doppler and the terminal antenna pointing direction. Use the signal Doppler to determine the acquisition parameters, including the frequency search range and acquisition threshold.

[0098] Step 4: Signal Acquisition Control: Adjust the antenna pointing and channel according to the calculated terminal antenna pointing and signal parameters to acquire satellite signals.

[0099] To account for deviations from the pre-loaded satellite service plan on the terminal, the specific procedure for signal acquisition control is as follows:

[0100] Step 41, Signal Acquisition: Based on the acquisition parameters, control the terminal to acquire satellite signals and simultaneously start the single acquisition timer Ts;

[0101] Step 42, jump control: If the acquisition is successful, the signal is received and the process proceeds to step 5; if the single acquisition timer Ts completes, the process checks whether there are any new serviceable satellites in the queue of service satellites to be acquired {STi}. If there are serviceable satellites STi, the process jumps to step 3 to calculate the acquisition parameters and re-acquire the signal; otherwise, the process jumps to step 4.3.

[0102] Step 43, orbital plane search: Referring to the satellites and their ephemeris given in the plan, calculate the possible orbital position deviation of the satellites according to the satellite ephemeris time deviation probability model, generate virtual orbital positions, reconstruct the service satellite search set, generate virtual ephemeris, jump to step 32, calculate the acquisition parameters, and re-initiate the acquisition.

[0103] Step 44, Error Reporting: If the total capture timer Ta completes, stop signal capture and report an access error.

[0104] Figure 5A process for capturing giant constellation terminals based on satellite service contingency plans is presented.

[0105] Step 5: Obtain system parameters:

[0106] It receives captured satellite user link downlink signals, parses the frame content according to the frame format, and obtains system information, ephemeris information, and uplink parameter information based on system settings.

[0107] Step 6: Uplink signal access:

[0108] The satellite position is calculated based on the acquired ephemeris information. Combined with the terminal position information and uplink frequency parameters, the satellite-to-ground propagation delay and uplink signal Doppler are calculated. Based on the random access time slot specified by the system information, the uplink signal is transmitted to access the system.

[0109] Step 7: Update the contingency plan online

[0110] After the terminal connects to the system, it actively acquires or monitors satellite service plan broadcast messages, receives all or part of the service satellite plan broadcast by the system, updates the local satellite service plan, and ensures the efficiency of terminal access to the system.

[0111] Considering the varying update frequencies of different parts of the contingency plan, the online updates of the mega-constellation terminal contingency plan based on the satellite service contingency plan include the following methods:

[0112] Broadcast data update: The terminal receives ephemeris information and other data broadcast by the system and updates the corresponding data in the satellite service plan;

[0113] Application for update: The terminal can proactively apply for a full or partial update, and supports separate updates of satellite identifiers, ephemeris, and service satellite plans.

[0114] The embodiments described above do not constitute a limitation on the scope of protection of this application.

Claims

1. A method for accessing a giant constellation terminal based on a satellite service plan, characterized in that, The method includes: Step 1: Terminal initialization; Step 2: Selecting a Service Satellite Based on the satellite service plan settings, the terminal's own location and time information, the system searches for available satellites and forms a queue of satellites to be acquired. The selection of service satellites is based on the terminal time. Step 3: Determine the capture parameters: From the queue of service satellites to be captured { In the process, available satellites are extracted in sequence, signal Doppler is calculated, and acquisition parameters, including terminal antenna pointing, frequency search range, and acquisition threshold, are determined. Step 4: Signal Acquisition Control Adjust the antenna pointing and channel according to the calculated terminal antenna pointing and signal parameters to acquire satellite signals; Step 5: Obtain system parameters: It receives captured satellite user link downlink signals, parses frame content according to frame format, and obtains system information, ephemeris information, and uplink parameter information based on system settings. Step 6: Uplink signal access: The satellite position is calculated based on the acquired ephemeris information. Combined with the terminal position information and uplink frequency parameters, the satellite-to-ground propagation delay and uplink signal Doppler are calculated. Based on the random access time slot specified by the system information, the uplink signal is transmitted and the system is accessed. Step 7: Online update of the contingency plan: After the terminal accesses the system, it actively acquires or monitors satellite service plan broadcast messages, receives all or part of the service satellite plan broadcast by the system, updates the local satellite service plan, and ensures the efficiency of terminal access to the system. Step 4: Signal acquisition control, including: Step 41, Signal Acquisition: Based on the acquisition parameters, the control terminal acquires satellite signals and simultaneously starts a single acquisition timer. ; Step 42, Jump Control: If capture is successful, proceed to signal reception and go to step 5; if single capture timer... Once the timer completes, check the queue of service satellites to be captured. Are there any new servable satellites? If so, If the signal is captured, proceed to step 3 to calculate the capture parameters and re-capture the signal; otherwise, proceed to step 4.

3. Step 43, orbital plane search: Referring to the satellite ephemeris given in the plan, calculate the possible orbital position deviation of the satellite according to the satellite ephemeris time deviation probability model, generate virtual orbital position, reconstruct the service satellite search set, generate virtual ephemeris, jump to step 32, calculate the capture parameters, and re-initiate the capture. Step 44, Error Reporting: If the total capture timer is used... Once the timer completes, signal acquisition stops and an access anomaly is reported.

2. The method according to claim 1, characterized in that, Step 1: Terminal initialization, including: The software is loaded, and then the satellite navigation module is used to obtain the terminal's own location information. and time information ; For fixed-location terminals, location information can be obtained through pre-configuration, and time information is maintained using a timekeeping module.

3. The method according to claim 1, characterized in that, Step 2: Select serving satellites, including: Step 21, the terminal uses its own location information The ground service area identifier where the terminal is located can be retrieved from the pre-stored satellite service plan. ; Step 22, using terminal time information as a reference Utilizing the ground service area signs where the terminal is located Find available satellites for the current time period in the pre-loaded satellite service plan on the terminal; Step 23: According to the rules set in the satellite service plan, sort the service satellites in the ground service area where the terminal is located as given in the satellite service plan to form a queue of service satellites to be acquired. At the same time, start the total capture duration timer. .

4. The method according to claim 1, characterized in that, Step 3: Determine the capture parameters, including: Step 31, using the terminal's local time Based on the baseline, from the queue of service satellites to be captured { Obtain serviceable satellites in sequence. ; Step 32, using the extracted service satellites The identifier searches for its ephemeris in the satellite service plan and is based on the terminal's local time. The satellite's current position and motion vector are calculated using the satellite ephemeris data. Step 33: Combine the terminal location information and the satellite location information to calculate the elevation and azimuth of the terminal antenna, as well as the satellite-to-ground link loss. Based on the satellite motion vector information and the system downlink signal frequency, calculate the signal Doppler and the terminal antenna pointing direction. Use the signal Doppler to determine the acquisition parameters, including the frequency search range and acquisition threshold.

5. The method according to claim 1, characterized in that, Methods for updating contingency plans online include: Broadcast data update: The terminal receives ephemeris information broadcast by the system and updates the corresponding data in the satellite service plan; Application for update: The terminal can proactively apply for a full or partial update, and supports separate updates of satellite identifiers, ephemeris, and service satellite plans.

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