GNSS simulation test system and method

Abstract

The invention discloses a GNSS (Global Navigation Satellite System) simulation test system and method, and particularly relates to the technical field of wireless signal simulation. The primary module comprises a scheme setting module, a signal simulation module, a signal radiofrequency module and a test result analysis module; the scheme setting module is used for interacting with a user; a user sets / selects an analogue simulation scheme through the scheme setting module; the signal simulation module generates GNSS simulation data according to the simulation scheme; the signal radiofrequency module is used for converting the GNSS simulation data into a GNSS radiofrequency signal; the signal radiofrequency module is also used for being connected with an external to-be-tested terminal; the external to-be-tested terminal receives the GNSS radio frequency signal and generates a simulation result; and the test result analysis module generates a test report according to the analogue simulation scheme and the simulation result. Finally, the use difficulty is reduced, and the problem of poor compatibility is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless signal simulation, and in particular to a GNSS simulation test system and method. Background Art

[0002] GNSS stands for Global Navigation Satellite System, which is a space-based system that realizes global or regional positioning, navigation, and timing through satellite signals. Its core consists of a space segment (satellite constellation), a ground segment (control stations and monitoring stations), and a user segment (receiving devices). It can provide users with all-weather three-dimensional coordinates, speeds, and time information for space-based radio navigation positioning at any location on the Earth's surface or in near-Earth space, achieving global coverage of satellite navigation. GNSS simulation is to reproduce real satellite signals in a laboratory environment to solve the problems of uncontrollable signals, high costs, and single scenarios in actual tests. By simulating different satellite constellations (such as GPS, Beidou), dynamic trajectories (such as high-speed vehicle movement), and complex interferences (multipath effects, signal blockages), the positioning accuracy and anti-interference ability of devices in scenarios such as extreme weather and urban canyons can be efficiently verified, avoiding the high risks and non-repeatability of real tests, and at the same time supporting the efficient research and development and standardized testing in fields such as autonomous driving and aerospace.

[0003] There are a series of significant limitations and deficiencies in the current GNSS simulation test technology, which are specifically manifested as follows:

[0004] (1) Poor authenticity and reliability: Most still rely on traditional FPGA architectures with limited parallel computing capabilities, making it difficult to accurately model and calculate the orbits of a large number of satellites and the signal propagation process simultaneously. At the same time, due to the complexity of signal interference, satellite geometry, and atmospheric conditions, accurate simulation cannot be achieved. When performing full-constellation full-frequency point simulations close to the real world, the generated simulation signals are difficult to achieve both signal quality and quantity, resulting in deviations between simulation results and real scenarios.

[0005] (2) Poor standard compatibility: There are various standards for positioning terminal testing and rich scenario requirements. Existing solutions have low sensitivity and are difficult to quickly adapt to different standards of different users, and cannot achieve rapid automation. If users want to build an adaptive automated test system that meets their own standards, they often need to have strong development capabilities and invest a large amount of time and capital costs.

[0006] (3) Lack of application openness: Most of these devices are only used as "instruments", lacking the ability to support real application scenarios. The support for the device under test is insufficient, the data processing ability is weak, and there are also obvious shortcomings in the flexible integration and interconnection with external systems.

[0007] (4) Limited flexibility and scalability: Traditional devices rely on pre-written firmware programs, lacking the ability to dynamically allocate resources and update in real time. It is difficult to meet diverse signal requirements and flexibly adapt to changes in application scenarios.

[0008] (5) Complicated operation and use: The physical structure of the device is complex. In the face of complex application scenarios such as HIL and RTK, additional devices and tools often need to be added, which not only greatly increases the difficulty of use, resulting in inconvenient control, but also requires effort in the design and implementation of complex control systems. Summary of the Invention

[0009] In view of the problems existing in the prior art, the present invention provides a GNSS simulation test system and method, which can reduce the difficulty of use, solve the problem of poor compatibility, can adapt to multiple manufacturer protocols, and at the same time solve the problems of poor authenticity and reliability existing in the prior art.

[0010] The technical solution of the present invention is realized as follows:

[0011] A GNSS simulation test system includes a primary module; the primary module includes a scheme setting module, a signal simulation module, a signal radio frequency conversion module, and a test result analysis module;

[0012] The scheme setting module is used for interaction with the user; the user sets / selects a simulation scheme through the scheme setting module;

[0013] The signal simulation module generates GNSS simulation data according to the simulation scheme;

[0014] The signal radio frequency conversion module is used to convert the GNSS simulation data into a GNSS radio frequency signal; the signal radio frequency conversion module is also used to connect to an external terminal to be tested; the external terminal to be tested receives the GNSS radio frequency signal and generates a simulation result;

[0015] The test result analysis module generates a test report according to the simulation scheme and the simulation result.

[0016] Multiple groups of preset schemes are pre-stored in the system. Specifically, in actual applications, each group of preset schemes corresponds to a specification standard for a test process. This standard can be a national or industry-common standard. The specific content involves the simulation of test scenarios / environments and the simulation of GNSS signal generation and transceiver processes, such as "JJF 1921—2021 Calibration Specification for GNSS Driving Recorders". The user can directly select a test standard, complete the setting with one key, and directly perform GNSS signal simulation tests on the external terminal to be tested.

[0017] The present invention adopts a full-link closed-loop test architecture, innovatively realizing a highly integrated design of the GNSS simulation test system. Through standardized hardware interfaces, it can directly establish a physical layer direct connection with various terminals under test, supporting multi-frequency signal simulation, dynamic trajectory simulation, and anti-interference test scenarios. The system is based on an integrated platform, abandoning the dependence on third-party software platforms and external parsing devices in traditional solutions, effectively eliminating the risk of leakage of test data and processes. Through a visual human-computer interaction interface, it realizes one-key configuration of test parameters and automatic parsing of results, simplifies the usage process, and significantly reduces the operation complexity and learning cost.

[0018] As a further optimization of the above solution, some or all of the first-level modules further include second-level modules;

[0019] The solution setting module has multiple second-level modules, including a human-computer interaction module, a scenario construction module, a process construction module, a test process module, and a processing and analysis module;

[0020] The user interacts with the solution setting module through the human-computer interaction module; the human-computer interaction module provides the main software front-end interaction interface, providing users with a series of functions such as hardware configuration, test process observation, and result display. Through this part, GNSS testing no longer requires complex device configuration, GNSS simulator programming, and huge data extremes. Users only need to select the corresponding standard to obtain the final report after the automated test.

[0021] The scenario construction module reads and parses the simulation scheme to generate a simulation environment; the scenario construction module can read and extract the scenario construction process of the GNSS test environment according to the pre-stored standards selected by the user. The test environment includes signal conditions, satellite distribution requirements, signal power requirements, position and trajectory requirements, etc. required for GNSS testing.

[0022] The process construction module is used to construct the GNSS signal simulation test process; specifically, it can generate an automated process based on the test steps, test duration, adjustment range and step, configuration method, etc. in the standard.

[0023] The test process module controls and schedules the signal simulation module according to the GNSS signal simulation test process;

[0024] The processing and analysis module interacts with the test result analysis module according to the simulation scheme, calculates the error between the simulation scheme and the simulation result, generates the test report, and returns it to the human-computer interaction module.

[0025] As a further optimization of the above solution, the solution setting module further includes a virtual server module; the virtual server module receives an instruction from the test process module, denoted as the first instruction; the virtual server module integrates, parses, and encapsulates multiple first instructions into multiple second instructions; the second instruction is a sequential instruction with a timestamp; the first instruction and the second instruction are not in a one-to-one mapping relationship;

[0026] The virtual server module sends the second instructions to the signal simulation module in chronological order.

[0027] This solution relies on the virtual server module to build a non-direct connection communication mode between each secondary module and the signal simulation module. The virtual server module is used to uniformly receive GNSS simulation signal generation instructions, which include test sequence configuration parameters, batch execution instructions, trigger signals, etc.

[0028] For the first instruction, the virtual server module first passes the verification. After confirming that the information is correct, it sorts and encapsulates, and then publishes a control name based on the free instruction set of the simulation, and converts it into a secondary instruction.

[0029] Therefore, by setting up a virtual server, it is possible to provide batch and sequential scheduling capabilities for the test process, change the current situation where instrument equipment needs to be controlled in real time in the existing technology, and ensure that users can perform batch tests in sequence with a single operation. At the same time, it also provides the ability to protect and verify privacy standards. The entire workflow only runs within this part, and all interactions are transmitted after being verified, protected, and mapped by the middleware, ensuring that the user's standards and process designs are not obtained by external instrument equipment; external test data is transmitted back to this part in its original state and then re-compared and interpreted, ensuring that the parsed data does not leak.

[0030] As a further optimization of the above solution, the system integration is provided with multiple hardware units, including a logic processing unit, an IQ data operation unit, and a radio frequency signal conversion unit;

[0031] The instructions generated by the solution setting module and the signal simulation module are executed by the logic processing unit;

[0032] Among them, the signal simulation module also generates final GNSS simulation data by scheduling the IQ data calculation module; the signal radio frequency module schedules the radio frequency signal conversion unit to convert the GNSS simulation data into GNSS radio frequency signals.

[0033] The logic processing unit is responsible for coordinating the instruction flow and data flow, including: parsing parameters from the solution setting module (such as satellite orbits, signal frequencies, modulation methods, etc.); executing the generation logic of the signal simulation module, scheduling IQ data operations and radio frequency signal conversions; ensuring the timing synchronization of each module to meet real-time requirements, etc.

[0034] The IQ data operation unit is a hardware or software module dedicated to processing in-phase (I) and quadrature (Q) component data. Its core function is to perform mathematical operations on baseband signals in complex form to support key tasks such as modulation and demodulation, signal analysis, and synchronization in communication systems. Specifically, the IQ data operation unit can be a GPU, which can replace the signals generated by the FPGA by leveraging the multi-core parallel processing ability, matrix operation and vector calculation processing ability, and floating-point operation ability of the GPU.

[0035] The present invention also provides a GNSS simulation test method, which applies the above-mentioned GNSS simulation test system and includes the following steps:

[0036] S1. Wirelessly or wiredly connect the system to the external terminal to be tested.

[0037] S2. The user sets or selects one or more simulation scenarios through the scenario setting module.

[0038] S3. The signal simulation module analyzes the simulation scenario and generates GNSS simulation data.

[0039] S4. The signal radio frequency module receives the GNSS simulation data, converts it into a GNSS radio frequency signal, and then sends the GNSS radio frequency signal to the external terminal to be tested.

[0040] S5. The external terminal to be tested returns the simulation result to the test result analysis module; the test result analysis module and the scenario setting module interact based on the simulation result, generate a test report, and return it to the user.

[0041] As a further optimization of the above solution, the system stores an internal ephemeris file; the parsing is as follows: obtaining the trajectory path and the specified constellation frequency points according to the simulation scenario; the trajectory path consists of multiple ground simulation positions, including the initial position; each ground simulation position corresponds to a simulation time.

[0042] Using the internal ephemeris file, Kepler's equation, and orbital mechanics formula, confirm the spatial positions of one or more target satellites according to the simulation time and the ground simulation positions; one target satellite corresponds to one pseudo-random noise code.

[0043] Distribute operation tasks to each target satellite; the operation tasks of different target satellites are executed in parallel; specifically, assign GPU threads to each operation task.

[0044] The operation task is that the target satellite calculates the relative position relationship information with the ground simulation position, including distance and angle; generates baseband information according to the relative position relationship information, where the baseband information includes phase and amplitude; combines the baseband signal with the pseudo-random noise code for spreading spectrum and modulates it onto a carrier wave;

[0045] The carrier wave is the GNSS simulation data.

[0046] As a further optimization of the above solution, in S3, the trajectory path is generated according to the trajectory generation algorithm;

[0047] S3-1: Obtain the position information of the initial position, including longitude, latitude, and altitude; obtain the trajectory type, where the trajectory type is uniform linear motion, uniformly accelerated linear motion, or uniform circular motion;

[0048] S3-2: Convert the coordinates of the initial position according to the position information, that is:

[0049]

[0050] where (x0, y0, z0) are the coordinates of the initial position; λ, h respectively represent the longitude, the latitude, and the altitude; N represents the radius of curvature of the prime vertical; e 2 represents the first eccentricity; the radius of curvature of the prime vertical and the first eccentricity are relevant spatial parameters of the earth itself;

[0051] In the trajectory path, for the simulation time i, the coordinates corresponding to the ground simulation position are (x i , y i , z i ); taking the coordinates (x i , y i , z i ) as a reference, calculate the three-axis offset (N1, E1, D1) according to the trajectory type; obtain the coordinates of the ground simulation position corresponding to the simulation time i + 1 according to the coordinates (x i , y i , z i ) and the three-axis offset (N1, E1, D1), that is, (x i+1 , y i+1 , z i+1 ) = (x i + N1, y i + E1, z i + D1);

[0052] S3-4: Repeat S3-3 until the preset iteration termination condition is reached, and complete the generation of all the ground simulation positions.

[0053] As a further optimization of the above solution, the simulation scheme includes speed, acceleration, and direction; by setting the speed, acceleration, and direction in the scheme setting module, the setting of the trajectory type is completed.

[0054] Compared with the prior art, the present invention has the following beneficial effects:

[0055] (1) The present invention adopts a full-link closed-loop test architecture, and at the software level and the hardware level, innovatively realizes a highly integrated and integrated design of the GNSS simulation test system. Through a standardized hardware interface, it can directly establish a physical layer direct connection with various terminals to be tested, support multi-frequency signal simulation, dynamic trajectory simulation, and anti-interference test scenarios, and realizes full-process coverage from signal generation, scenario construction to terminal testing as long as the terminal to be tested is accessed.

[0056] (2) The system is based on an integrated platform, abandons the dependence on third-party software platforms and external parsing devices in traditional solutions, effectively eliminates the risk of leakage of test data and processes, and has higher security; and it can be used out of the box, and users do not need to perform complex configuration operations on different third-party hardware systems and software systems.

[0057] (3) Through a visual human-computer interaction interface, one-key configuration of test parameters and automatic parsing of results are realized. On the one hand, the use process is simplified, the operation complexity and learning cost are significantly reduced, and users can complete the test with one key without learning and researching standards; on the other hand, it can adapt to a variety of test protocols and standards, that is, directly build in test process cases of various mainstream national standards and industry standards; at the same time, an open interface is provided, and users can customize the full process of the test.

[0058] (4) A GPU-based IQ data calculation module is provided to realize parallel operation generation for simulation signals, replacing the traditional FPGA technology architecture in the industry, and achieving more efficient and comprehensive GNSS signal simulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 is a schematic diagram of the interaction of each module and unit of a GNSS simulation test system provided by an embodiment of the present invention;

[0060] Figure 2 is a schematic diagram of the interaction of the secondary module provided by an embodiment of the present invention;

[0061] Figure 3 is a schematic diagram of a partial process of a GNSS simulation test process provided by an embodiment of the present invention;

[0062] Figure 4 is a schematic diagram of the interface effect of a GNSS simulation test system provided by an embodiment of the present invention;

[0063] Figure 5 It is a schematic diagram of the interaction of various systems and devices in GNSS simulation in the prior art provided by an embodiment of the present invention. Specific Embodiments

[0064] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0065] As Figures 1 to 4 shown, this embodiment provides a GNSS simulation test system, including a primary module; the primary module includes a scheme setting module, a signal simulation module, a signal radio frequency module, and a test result analysis module;

[0066] The scheme setting module is used for interacting with the user; the user sets / selects a simulation scheme through the scheme setting module; multiple groups of preset schemes are pre-stored in the system. In practical applications, each group of preset schemes corresponds to a specification standard for a test process, and this standard can be a standard announced by the state or commonly used in the industry. The specific content involves the simulation of the test scenario / environment, as well as the simulation of the GNSS signal generation and transceiver process. The user can directly select a test standard, complete the setting with one key, and directly perform GNSS signal simulation tests on the external terminal to be tested.

[0067] Specifically, the scheme setting module has multiple secondary modules, including a human-computer interaction module, a scenario construction module, a process construction module, a test process module, a processing and analysis module, and a virtual server module;

[0068] The user interacts with the scheme setting module through the human-computer interaction module; the human-computer interaction module provides the main software front-end interaction interface, providing a series of functions for the user such as hardware configuration, test process observation, and result display. Through this part, GNSS testing no longer requires relatively complex device configuration, GNSS simulator programming, and huge data extremes. The user only needs to select the corresponding standard to obtain the final report after the automated test.

[0069] The scenario construction module reads and analyzes the simulation scheme to generate a simulation environment; the scenario construction module can read and extract the scenario construction process of the GNSS test environment according to the pre-stored standard selected by the user. The test environment includes signal conditions required for GNSS testing, satellite distribution requirements, signal power requirements, position and trajectory requirements (trajectory requirements such as direction, speed, and acceleration), etc.

[0070] The process construction module is used to construct the GNSS signal simulation test process; specifically, it can generate an automated process based on the test steps, test duration (such as completing one round of testing in 15 minutes), adjustment range and step, configuration method, etc. in the standard.

[0071] In this embodiment, the process of the simulation process includes: satellite calculation process, signal operation process, and radio frequency conversion process.

[0072] After receiving the time to be simulated, trajectory path, and specified constellation frequency points provided by the front end, the satellite calculation process will use the built-in ephemeris file, and with the help of Kepler's equation and orbital mechanics formulas, quickly confirm the satellite spatial positions corresponding to the current time and current position under the specified constellation frequency points, and distribute the calculation tasks of each satellite to different threads of the GPU.

[0073] After receiving the pre - set instructions, the signal operation will calculate information such as the distance and angle from the allocated satellites to the ground simulation position, and start to generate the corresponding baseband information, including phase, amplitude, etc. After spreading the signal with the specific pseudo - random noise code of each satellite and modulating it onto the carrier, this information will be continuously output to the subsequent process.

[0074] After receiving the pre - set data, the radio frequency conversion process needs to call the signal radio frequency module to convert the signal into a radio frequency analog signal with a specific energy magnitude and phase state, and then transmit it.

[0075] The test process module controls and schedules the signal simulation module according to the GNSS signal simulation test process; specifically, the test process module uniformly packages the above - mentioned information, transfers it to the virtual server module, and establishes a stable communication with the signal simulation module through the virtual server module.

[0076] The virtual server module receives the instructions from the test process module, denoted as the first instructions.

[0077] The virtual server module integrates, analyzes, and packages multiple first instructions into multiple second instructions; the second instructions are sequential instructions with time stamps; the first instructions and the second instructions do not have a one - to - one mapping relationship.

[0078] In this embodiment, a set of custom Auto instruction sets is designed for the integrated system equipment of this application; the first instruction is one of the Auto instruction sets; for the GNSS signal simulation module, a general instruction set is adopted, which is a general instruction for the GNSS signal generation function, that is, the second instruction is only used to schedule the signal simulation module to complete the generation and simulation of GNSS signals.

[0079] The virtual server module sends the second instructions to the signal simulation module in chronological order.

[0080] This solution relies on the virtual server module to build a non-direct connection communication mode between each secondary module and the signal simulation module. The virtual server module is used to uniformly receive GNSS simulation signal generation instructions, including test sequence configuration parameters, batch execution instructions, trigger signals, etc.

[0081] For the first instruction, the virtual server module first verifies it, sorts and encapsulates it after confirming that the information is correct, and then publishes the control name based on the free instruction set of the simulation and converts it into a secondary instruction. In particular, the virtual server module sends the second instruction to the signal simulation module in batches.

[0082] In the prior art, there are problems of architecture redundancy and protocol heterogeneity in the GNSS signal generation test system. The traditional solution requires multiple sets of independent systems to run in coordination. For example, the control terminal (System A), as the human-computer interaction and process scheduling center (i.e., the backend control), needs to connect to the GNSS signal generation system (System B), and the latter is only responsible for generating and simulating signal output to the device under test (such as a GPS unit); in some scenarios, an independent analysis system (System C) also needs to be configured to complete data backhaul parsing, analysis, and result feedback. This architecture not only requires real-time interconnection of each system, but also due to the different communication protocols, test standards, and dedicated control interfaces provided by System B of different manufacturers, the system integration complexity is high, and the cross-platform compatibility is poor, significantly increasing the test environment deployment and maintenance costs.

[0083] Therefore, by setting up a virtual server, it is possible to provide batch and sequential scheduling capabilities for the test process, changing the current situation where instrument devices need to be controlled in real time in the prior art, and eliminating the need for specific control logic and instructions, ensuring that users can perform batch tests in sequence with a single operation. At the same time, it also provides the ability to protect and verify privacy standards. The entire workflow only runs within this part, and all interactions are transmitted after being verified, protected, and mapped by the middleware, ensuring that the user's standards and process designs are not obtained by external instrument devices; external test data is transmitted back to this part in its original state and then re-compared and interpreted to ensure that the parsed data does not leak.

[0084] The signal simulation module generates GNSS simulation data according to the simulation scheme;

[0085] The signal radio frequency module is used to convert GNSS simulation data into GNSS radio frequency signals; the signal radio frequency module is also used to connect to the external terminal to be tested; the external terminal to be tested receives the GNSS radio frequency signal and generates simulation results, including NMEA data, RTCM data, etc.;

[0086] The test result analysis module generates a test report based on the simulation scheme and the simulation results.

[0087] The simulation scheme includes reference results; the processing and analysis module interacts with the test result analysis module according to the simulation scheme, calculates the error between the simulation scheme and the simulation results, generates a test report and returns it to the human-computer interaction module.

[0088] The present invention adopts a full-link closed-loop test architecture, innovatively realizes the highly integrated design of the GNSS simulation test system, can directly establish a physical layer direct connection with various terminals to be tested through a standardized hardware interface, and supports multi-frequency signal simulation, dynamic trajectory simulation and anti-interference test scenarios. The system is based on an integrated platform, abandons the dependence on third-party software platforms and external parsing devices in traditional solutions, effectively eliminates the risk of leakage of test data and processes, and realizes one-key configuration of test parameters and automatic parsing of results through a visual human-computer interaction interface, simplifies the usage process, and significantly reduces the operation complexity and learning cost.

[0089] In this embodiment, the system integration is provided with a plurality of hardware units, including a logic processing unit, an IQ data operation unit and a radio frequency signal conversion unit;

[0090] The instructions generated by the scheme setting module and the signal simulation module are executed by the logic processing unit;

[0091] Among them, the signal simulation module also generates the final GNSS simulation data by scheduling the IQ data calculation module; the signal radio frequency module schedules the radio frequency signal conversion unit to convert the GNSS simulation data into a GNSS radio frequency signal.

[0092] The logic processing unit is responsible for coordinating the instruction flow and data flow, including: parsing parameters from the scheme setting module (such as satellite orbit, signal frequency point, modulation method, etc.); executing the generation logic of the signal simulation module, scheduling IQ data operation and radio frequency signal conversion; ensuring the timing synchronization of each module to meet the real-time requirements, etc.

[0093] Specifically, the IQ data operation unit can be a GPU, and by exerting the multi-core parallel processing ability, matrix operation and vector calculation processing ability, and floating-point operation ability of the GPU, the replacement of the signal generated by the FPGA is realized.

[0094] This embodiment also provides a GNSS simulation test method, which applies the above-mentioned GNSS simulation test system, and includes the following steps:

[0095] S1. Wiredly connect the system and the external terminal to be tested;

[0096] S2. The user selects a simulation scheme through the scheme setting module, such as the "JJF 1921—2021 GNSS Driving Recorder Calibration Specification"; based on the specification, the scenario construction module parses to obtain scenario information, that is:

[0097] The simulation scenario is a multi-satellite single-frequency scenario; the simulated constellations are GPS L1C / A, BDS BII, Galileo E1, and GLONASS G1; the number of simulated satellites is 6; the simulated signal power level is 128 dm; the distribution index is PDOP < 4, etc.

[0098] S3. The signal simulation module analyzes the simulation scheme and generates GNSS simulation data; in this embodiment, the system stores a built-in ephemeris file; the analysis is as follows: obtain the trajectory path and the specified constellation frequency points according to the simulation scheme; the trajectory path consists of multiple ground simulation positions, including the initial position; each ground simulation position corresponds to a simulation time.

[0099] Using the built-in ephemeris file, Kepler's equation, and orbital mechanics formulas, confirm the spatial positions of one or more target satellites according to the simulation time and the ground simulation positions; one target satellite corresponds to a pseudo-random noise code.

[0100] Distribute computing tasks to each target satellite; the computing tasks of different target satellites are executed in parallel; specifically, allocate GPU threads to each computing task.

[0101] The computing task is for the target satellite to calculate the relative position relationship information with the ground simulation position, including distance and angle; generate baseband information according to the relative position relationship information, and the baseband information includes phase and amplitude; spread-spectrum the baseband signal in combination with the pseudo-random noise code and modulate it onto the carrier.

[0102] The carrier is the GNSS simulation data.

[0103] In this embodiment, generate the trajectory path according to the trajectory generation algorithm.

[0104] S3-1. Obtain the position information of the initial position, including longitude, latitude, and altitude; obtain the trajectory type, and the trajectory type is uniform linear motion, uniformly accelerated linear motion, or uniform circular motion; in this embodiment, the simulation scheme includes speed, acceleration, and direction; complete the setting of the trajectory type by setting the speed, acceleration, and direction in the scheme setting module. For example, in uniform motion, the speed is a constant, and the acceleration is set to 0.

[0105] S3-2. Convert the coordinates of the initial position according to the position information, that is:

[0106]

[0107] where (x0, y0, z0) are the coordinates of the initial position; λ, h represent longitude, latitude, and altitude respectively; N represents the radius of curvature of the prime vertical; e 2 represents the first eccentricity; the radius of curvature of the prime vertical and the first eccentricity are relevant spatial parameters of the earth itself.

[0108] S3-3. In the trajectory path, for the simulation time i, the coordinates of the corresponding ground simulation position are (x i , y i , z i ); Based on the coordinates (x i , y i , z i ), calculate the three-axis offset (N1, E1, D1) according to the trajectory type; According to the coordinates (x i , y i , z i ) and the three-axis offset (N1, E1, D1), obtain the coordinates of the ground simulation position corresponding to the simulation time i+1, that is, (x i+1 , y i+1 , z i+1 ) = (x i + N1, y i + E1, z i + D1);

[0109] S3-4. Repeat S3-3 until the preset iteration termination condition is reached to complete the generation of all ground simulation positions.

[0110] S4. The signal radio frequency module receives GNSS simulation data and converts it into GNSS radio frequency signals, and then sends the GNSS radio frequency signals to the external terminal to be tested;

[0111] S5. The external terminal to be tested returns the simulation results to the test result analysis module; The test result analysis module and the scheme setting module interact according to the simulation results, generate a test report and return it to the user.

[0112] Specifically, during the simulation test run, if no data feedback from the external terminal to be tested is collected within a predetermined time period (such as within 3 minutes), it is determined that the test fails and the test ends; If received, continue the test for 15 minutes, and collect the positioning information feedback from the external terminal to be tested at a sampling interval of 1 s; Compare the feedback positioning information with the simulated trajectory information to obtain the error result. Output and display the relevant information of successful or failed tests through means such as PDF and web pages.

[0113] According to the disclosure and teaching of the above specification, those skilled in the art to which the present invention pertains can also make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the present invention should also fall within the protection scope of the claims of the present invention. In addition, although some specific terms are used in this specification, these terms are only for convenience of description and do not constitute any limitation to the present invention.

Claims

1. A GNSS simulation test system, characterized in that, It includes a first-level module; the first-level module includes a scheme setting module, a signal simulation module, a signal radio frequency conversion module, and a test result analysis module; The scheme setting module is used for interacting with the user; the user sets / selects a simulation scheme through the scheme setting module; The signal simulation module generates GNSS simulation data according to the simulation scheme; The signal radio frequency conversion module is used to convert the GNSS simulation data into a GNSS radio frequency signal; The signal radio frequency conversion module is also used to connect to an external terminal to be tested; the external terminal to be tested receives the GNSS radio frequency signal and generates a simulation result; The test result analysis module generates a test report according to the simulation scheme and the simulation result.

2. The GNSS simulation test system according to claim 1, characterized in that, Some or all of the first-level modules further include second-level modules; The scheme setting module has a plurality of second-level modules, including a human-computer interaction module, a scenario construction module, a process construction module, a test process module, and a processing and analysis module; The user interacts with the scheme setting module through the human-computer interaction module; The scenario construction module reads and analyzes the simulation scheme to generate a simulation environment; The process construction module is used to construct a GNSS signal simulation test process; The test process module controls and schedules the signal simulation module according to the GNSS signal simulation test process; The processing and analysis module interacts with the test result analysis module according to the simulation scheme, calculates the error between the simulation scheme and the simulation result, generates the test report and returns it to the human-computer interaction module.

3. A GNSS simulation test system according to claim 2, characterized in that, The scheme setting module further includes a virtual server module; the virtual server module receives an instruction from the test process module, denoted as the first instruction; the virtual server module integrates, analyzes, and encapsulates a plurality of the first instructions into a plurality of second instructions; the second instruction is a sequential instruction with a timestamp; the first instruction and the second instruction are not in a one-to-one mapping relationship; The virtual server module sends the second instructions to the signal simulation module in chronological order.

4. A GNSS simulation test system according to claim 1, characterized in that, The system integration is provided with a plurality of hardware units, including a logic processing unit, an IQ data operation unit, and a radio frequency signal conversion unit; The instructions generated by the scheme setting module and the signal simulation module are executed by the logic processing unit; Among them, the signal simulation module also generates the final GNSS simulation data by scheduling the IQ data operation module; the signal radio frequency conversion module schedules the radio frequency signal conversion unit to convert the GNSS simulation data into a GNSS radio frequency signal.

5. A GNSS simulation test method, characterized in that, Applying a GNSS simulation test system according to any one of claims 1 to 4, includes the following steps: S1. Wirelessly or wired connect the system and the external terminal to be tested; S2. The user sets or selects one or more simulation schemes through the scheme setting module; S3. The signal simulation module analyzes the simulation scheme to generate GNSS simulation data; S4. The signal radio frequency module receives the GNSS simulation data, converts it into a GNSS radio frequency signal, and then sends the GNSS radio frequency signal to the external terminal to be tested; S5. The external terminal to be tested returns the simulation result to the test result analysis module; The test result analysis module and the solution setting module interact according to the simulation result, generate a test report and return it to the user.

6. The GNSS simulation test method according to claim 5, characterized in that, The system stores a built-in ephemeris file; The parsing is: obtaining the trajectory path and the specified constellation frequency points according to the simulation scheme; The trajectory path is composed of multiple ground simulation positions, including the initial position; Each of the ground simulation positions corresponds to a simulation time; Using the built-in ephemeris file, Kepler's equation and orbital mechanics formula, confirm the spatial positions of one or more target satellites according to the simulation time and the ground simulation positions; One of the target satellites corresponds to a pseudo-random noise code; Distribute computing tasks to each of the target satellites; The computing tasks of different target satellites are executed in parallel; The computing task is that the target satellite calculates the relative position relationship information with the ground simulation position, including distance and angle; Generate baseband information according to the relative position relationship information, and the baseband information includes phase and amplitude; Spread-spectrum the baseband signal in combination with the pseudo-random noise code and modulate it onto the carrier; The carrier is the GNSS simulation data.

7. A GNSS simulation test method according to claim 6, characterized in that, In S3, generate the trajectory path according to the trajectory generation algorithm; S3-1. Obtain the position information of the initial position, including longitude, latitude and altitude; Obtain the trajectory type, and the trajectory type is uniform linear motion, uniformly accelerated linear motion or uniform circular motion; S3-2. Convert the coordinates of the initial position according to the position information, that is: where (x0, y0, z0) are the coordinates of the initial position; λ and h respectively represent the longitude, the latitude, and the altitude; N represents the radius of curvature of the prime vertical, and e 2 represents the first eccentricity; S3-3. In the described trajectory path, for simulation time i, the coordinates corresponding to the ground simulation position are (x i , y i , z i ); based on the coordinates (x i , y i , z i ), calculate the three-axis offset (N1, E1, D1) according to the described trajectory type; based on the coordinates (x i , y i , z i ) and the three-axis offset (N1, E1, D1), obtain the coordinates of the ground simulation position corresponding to simulation time i + 1, that is, (x i+1 , y i+1 , z i+1 ) = (x i + N1, y i + E1, z i + D1); S3-4. Repeat S3-3 until a preset iteration termination condition is reached, and complete the generation of all the ground simulation positions.

8. A GNSS simulation test method according to claim 7, characterized in that, The simulation scheme includes speed, acceleration and direction; By setting speed, acceleration and direction in the solution setting module, the setting of the trajectory type is completed.

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