Real-time closed-loop satellite navigation simulation system

Abstract

The invention discloses a real-time closed-loop satellite navigation simulation system, which relates to the technical field of satellite navigation simulation testing and comprises an outdoor navigation signal purification unit and an indoor real-time closed-loop simulation system. The outdoor navigation signal purification unit comprises a high-gain antenna and a signal processing system and is used for searching a navigation satellite in real time and extracting signal parameters; the indoor real-time closed-loop simulation system comprises a motion controller, a satellite navigation receiver and a real-time closed-loop satellite navigation simulator; the real-time closed-loop satellite navigation simulator comprises a satellite navigation signal parameter simulation unit and a satellite navigation real-time signal generation unit; the motion controller communicates with the satellite navigation signal parameter simulation unit through the optical fiber reflection memory; the satellite navigation real-time signal generation unit transmits a simulation signal to a satellite navigation receiver. According to the invention, the defect that a semi-physical simulation system in the prior art cannot support actual constellation error simulation and does not support authorization signals can be overcome.

Description

Technical Field

[0001] The invention relates to the technical field of satellite navigation simulation testing, in particular to a real-time closed-loop satellite navigation simulation system. Background Art

[0002] Satellite navigation technology has the advantages of high precision, all-weather and all-day operation. It is currently the most widely used means of navigation and positioning. In mobile platforms, it is generally integrated with other systems such as inertial navigation, visual navigation, and motion control systems, and uses semi-physical hardware in-the-loop real-time closed-loop methods for simulation testing.

[0003] The current semi-physical simulation system uses a purely mathematical simulation method with parameter configuration for various ionosphere, troposphere and other errors, which does not adequately reflect the actual conditions of the actual satellite constellation; it cannot support the simulation of actual constellation errors and does not support authorization signals; in addition, due to the encryption characteristics of the authorization signal, there is no signal source that can be directly generated. The current real-time closed-loop simulation system can only generate civil signals, and is even more unable to simulate and test the authorized receivers of various satellite navigation systems; the testing of some receivers in high-dynamic scenarios cannot be completed in the laboratory, and can only be verified through actual field or flight tests. The test has poor repeatability, high cost, and insufficient scenario traversal. Summary of the invention

[0004] The purpose of the present invention is to provide a real-time closed-loop satellite navigation simulation system to solve the problems raised in the prior art.

[0005] To achieve the above object, the present invention provides the following technical solutions: a real-time closed-loop satellite navigation simulation system, which is composed of an outdoor navigation signal purification unit and an indoor real-time closed-loop simulation system; the outdoor navigation signal purification unit includes a high-gain antenna and a signal processing system, and the indoor real-time closed-loop simulation system includes a motion controller, a satellite navigation receiver and a real-time closed-loop satellite navigation simulator, wherein the real-time closed-loop simulator is divided into a satellite navigation signal parameter simulation unit and a satellite navigation real-time signal generation unit; The high-gain antenna of the outdoor navigation signal purification unit adopts a digital multi-beam active phased array antenna, or multiple high-gain passive antennas, with a gain of no less than 20dBi; the high-gain antenna can simultaneously track no less than 16 navigation satellites in real time and perform digital sampling on the frequency band of interest; The signal processing system of the outdoor navigation signal purification unit processes the digital sampling stream of each satellite to obtain real-time estimation of the spread spectrum code chips of the navigation signals of concern to multiple satellites; the outdoor navigation signal purification unit not only performs real-time chip estimation of the civil signals in the concerned frequency band, but also performs real-time chip estimation of the authorized signals in the same frequency band; The signal processing system of the outdoor navigation signal purification unit performs conventional navigation positioning calculations on the civil signals in the navigation frequency band of interest to obtain the current real-time time and ephemeris parameters of all satellites; The signal processing system of the outdoor navigation signal purification unit transmits the current real-time time, all satellite ephemeris parameters and real-time chip estimation of all signals to the indoor satellite navigation real-time signal generation unit through an optical fiber link; The indoor satellite navigation real-time signal generation unit synchronizes the current real-time time to the satellite navigation signal parameter simulation unit, and then synchronizes the real-time time to the motion controller through the satellite navigation signal parameter simulation unit; The indoor motion controller is a simulation computer that dynamically adjusts the motion trajectory in real time according to the real-time position received by the indoor satellite navigation receiver and the motion control strategy; the simulated motion time is synchronized with the current real-time time, and the future time cannot be set; The indoor motion controller sends the real-time position, speed, acceleration and other information of no less than 100Hz to the satellite navigation signal parameter simulation unit according to the timestamp through the optical fiber reflection memory; The satellite navigation signal parameter simulation unit receives the current real-time ephemeris forwarded from the satellite navigation real-time signal generation unit, and is not allowed to modify or set other navigation satellite ephemeris parameters; The satellite navigation signal parameter simulation unit calculates the transmission distance and change speed of the satellite navigation signal according to the real-time motion parameters given by the motion controller and the current real-time ephemeris, converts them into corresponding pseudo-range and carrier phase, phase change rate and phase change acceleration and other control parameters, and sends them to the satellite navigation real-time signal generation unit in real time; The satellite navigation real-time signal generating unit calculates the real-time phase of the authorized navigation signal spread spectrum code simulated by the pseudo-range, and uses phase addressing to find the estimated value of the authorized signal spread spectrum code chip from the real-time estimated spread spectrum code stream; The satellite navigation real-time signal generation unit iteratively generates the authorized and unauthorized spread spectrum code baseband signals of the simulated frequency points according to the control parameters such as pseudorange change rate and change acceleration, and can turn off some of the authorized or unauthorized spread spectrum code components according to the simulation scene settings; The satellite navigation real-time signal generation unit iteratively generates the corresponding carrier signal according to the control parameters such as carrier phase, carrier phase change rate, carrier phase change acceleration, etc., and simulates the Doppler change law of the carrier with movement; The satellite navigation real-time signal generation unit multiplies the spread spectrum code baseband signal with the carrier signal to obtain a baseband signal with Doppler effect, which is then transmitted to the indoor satellite navigation receiver by wired or wireless radiation after digital-to-analog conversion and up-conversion to the navigation frequency band; The satellite navigation real-time signal generation unit outputs 1PPS and real-time time information to the indoor satellite navigation receiver to assist the satellite navigation receiver in directly capturing and receiving the authorization signal; The indoor satellite navigation receiver supports direct capture and reception of authorization signals using the approximate time information sent by the satellite navigation real-time signal generation unit; The indoor satellite navigation receiver sends the real-time navigation and positioning results to the motion controller for the motion controller to implement closed-loop dynamic control.

[0006] The real-time closed-loop satellite navigation simulation system proposed in the present invention does not directly use ordinary civilian public signals to simulate scenarios in which time, ephemeris and motion trajectory can be arbitrarily set, but uses a high-gain multi-beam antenna and a signal processing system to obtain a real-time spread spectrum code signal containing an authorization code component from the current actual satellite constellation. The simulated time is completely synchronized with the current time, the simulated ephemeris is based on the current actual ephemeris, and the simulated signal supports all or part of the authorization signal and the public signal. Through this system, the problem that the traditional real-time closed-loop satellite navigation simulation system cannot test the authorization code receiver can be solved, a high-dynamic real-time closed-loop simulation of the authorization code receiver is provided, and all actual errors of the satellite navigation constellation are included in the simulation scenario.

[0007] Compared with the prior art, the beneficial effects of the present invention are as follows: the real-time closed-loop satellite navigation simulation system proposed in the present invention does not directly use ordinary civilian public signals to simulate scenarios in which time, ephemeris and motion trajectory can be arbitrarily set, but uses a high-gain multi-beam antenna and a signal processing system to obtain a real-time spread spectrum code signal containing an authorization code component from the current actual satellite constellation. The simulated time is completely synchronized with the current time, the simulated ephemeris is based on the current actual ephemeris, and the simulated signal supports all or part of the authorization signal and the public signal; the real-time closed-loop system can simulate not only traditional civilian navigation signals, but also authorization signals, and apply various high dynamics and control strategies; the simulated signal contains the real errors that may be contained in the current real-time satellite constellation, and does not require the relevant authorization information of the satellite navigation system authorization signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 A schematic diagram of a real-time closed-loop satellite navigation simulation system according to an embodiment of the present invention; Figure 2 This is a schematic diagram of a first implementation of an outdoor navigation signal purification unit of the present invention; Figure 3 This is a schematic diagram of a second embodiment of an outdoor navigation signal purification unit of the present invention; Figure 4 A schematic diagram of a satellite navigation signal generation process according to an embodiment of the present invention; Figure 5A schematic diagram of the relationship between time synchronization and transmission in one embodiment of the present invention; Figure 6 The figure is a schematic diagram of generating a real-time satellite navigation signal according to an embodiment of the present invention. DETAILED DESCRIPTION

[0009] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0010] Example: Figure 1-Figure 6 As shown, the present invention provides a technical solution, a real-time closed-loop satellite navigation simulation system, which consists of an outdoor navigation signal purification unit and an indoor real-time closed-loop simulation system; the outdoor navigation signal purification unit includes a high-gain antenna and a signal processing system, and the indoor real-time closed-loop simulation system includes a motion controller, a satellite navigation receiver and a real-time closed-loop satellite navigation simulator, wherein the real-time closed-loop simulator is divided into a satellite navigation signal parameter simulation unit and a satellite navigation real-time signal generation unit; The high-gain antenna of the outdoor navigation signal purification unit adopts a digital multi-beam active phased array antenna, or multiple high-gain passive antennas, with a gain of no less than 20dBi; the high-gain antenna can simultaneously track no less than 16 navigation satellites in real time and perform digital sampling on the frequency band of interest; The signal processing system of the outdoor navigation signal purification unit processes the digital sampling stream of each satellite to obtain real-time estimation of the spread spectrum code chips of the navigation signals of concern to multiple satellites; the outdoor navigation signal purification unit not only performs real-time chip estimation of the civil signals in the concerned frequency band, but also performs real-time chip estimation of the authorized signals in the same frequency band; The signal processing system of the outdoor navigation signal purification unit performs conventional navigation positioning calculations on the civil signals in the navigation frequency band of interest to obtain the current real-time time and ephemeris parameters of all satellites; The signal processing system of the outdoor navigation signal purification unit transmits the current real-time time, all satellite ephemeris parameters and real-time chip estimation of all signals to the indoor satellite navigation real-time signal generation unit through an optical fiber link; The indoor satellite navigation real-time signal generation unit synchronizes the current real-time time to the satellite navigation signal parameter simulation unit, and then synchronizes the real-time time to the motion controller through the satellite navigation signal parameter simulation unit; The indoor motion controller is a simulation computer that dynamically adjusts the motion trajectory in real time according to the real-time position received by the indoor satellite navigation receiver and the motion control strategy; the simulated motion time is synchronized with the current real-time time, and the future time cannot be set; The indoor motion controller sends the real-time position, speed, acceleration and other information of no less than 100Hz to the satellite navigation signal parameter simulation unit according to the timestamp through the optical fiber reflection memory; The satellite navigation signal parameter simulation unit receives the current real-time ephemeris forwarded from the satellite navigation real-time signal generation unit, and is not allowed to modify or set other navigation satellite ephemeris parameters; The satellite navigation signal parameter simulation unit calculates the transmission distance and change speed of the satellite navigation signal according to the real-time motion parameters given by the motion controller and the current real-time ephemeris, converts them into corresponding pseudo-range and carrier phase, phase change rate and phase change acceleration and other control parameters, and sends them to the satellite navigation real-time signal generation unit in real time; The satellite navigation real-time signal generating unit calculates the real-time phase of the authorized navigation signal spread spectrum code simulated by the pseudo-range, and uses phase addressing to find the estimated value of the authorized signal spread spectrum code chip from the real-time estimated spread spectrum code stream; The satellite navigation real-time signal generation unit iteratively generates the authorized and unauthorized spread spectrum code baseband signals of the simulated frequency points according to the control parameters such as pseudorange change rate and change acceleration, and can turn off some of the authorized or unauthorized spread spectrum code components according to the simulation scene settings; The satellite navigation real-time signal generation unit iteratively generates the corresponding carrier signal according to the control parameters such as carrier phase, carrier phase change rate, carrier phase change acceleration, etc., and simulates the Doppler change law of the carrier with movement; The satellite navigation real-time signal generation unit multiplies the spread spectrum code baseband signal with the carrier signal to obtain a baseband signal with Doppler effect, which is then transmitted to the indoor satellite navigation receiver by wired or wireless radiation after digital-to-analog conversion and up-conversion to the navigation frequency band; The satellite navigation real-time signal generation unit outputs 1PPS and real-time time information to the indoor satellite navigation receiver to assist the satellite navigation receiver in directly capturing and receiving the authorization signal; The indoor satellite navigation receiver supports direct capture and reception of authorization signals using the approximate time information sent by the satellite navigation real-time signal generation unit; The indoor satellite navigation receiver sends the real-time navigation and positioning results to the motion controller for the motion controller to implement closed-loop dynamic control.

[0011] Figure 1The present invention is a schematic diagram of a real-time closed-loop satellite navigation simulation system according to an embodiment of the present invention; the system is composed of an outdoor navigation signal purification unit and an indoor real-time closed-loop simulation system; the outdoor navigation signal purification unit includes a high-gain antenna and a signal processing system; the indoor real-time closed-loop simulation system includes a motion controller, a satellite navigation receiver and a real-time closed-loop satellite navigation simulator; wherein the real-time closed-loop simulator is divided into a satellite navigation signal parameter simulation unit and a satellite navigation real-time signal generation unit; The signal processing system of the outdoor navigation signal purification unit processes the digital sampling stream of each satellite to obtain real-time estimation of the spread spectrum code chips of the navigation signals of concern to multiple satellites; the signal processing system not only estimates the code chips of the civil signals in the concerned frequency band in real time, but also estimates the code chips of the authorized signals in the same frequency band in real time; The signal processing system of the outdoor navigation signal purification unit performs conventional navigation positioning calculations on the civil signals in the navigation frequency band of interest to obtain the current real-time time and ephemeris parameters of all satellites; The indoor motion controller is a simulation computer that dynamically adjusts the motion trajectory in real time according to the real-time position received by the indoor satellite navigation receiver and the motion control strategy; the simulated motion time is synchronized with the current real-time time, and the future time cannot be set; The indoor motion controller sends the real-time position, speed, acceleration and other information of no less than 100Hz to the satellite navigation signal parameter simulation unit according to the timestamp through the optical fiber reflection memory; The satellite navigation signal parameter simulation unit receives the current real-time ephemeris forwarded from the satellite navigation real-time signal generation unit, and is not allowed to modify or set other navigation satellite ephemeris parameters; The satellite navigation signal parameter simulation unit calculates the transmission distance and change speed of the satellite navigation signal according to the real-time motion parameters given by the motion controller and the current real-time ephemeris, converts them into corresponding pseudo-range and carrier phase, phase change rate and phase change acceleration and other control parameters, and sends them to the satellite navigation real-time signal generation unit in real time; The satellite navigation real-time signal generating unit calculates the real-time phase of the authorized navigation signal spread spectrum code simulated by the pseudo-range, and uses phase addressing to find the estimated value of the authorized signal spread spectrum code chip from the real-time estimated spread spectrum code stream; The satellite navigation real-time signal generation unit iteratively generates the authorized and unauthorized spread spectrum code baseband signals of the simulated frequency points according to the control parameters such as pseudorange change rate and change acceleration, and can turn off some of the authorized or unauthorized spread spectrum code components according to the simulation scene settings; The satellite navigation real-time signal generation unit iteratively generates the corresponding carrier signal according to the carrier phase, carrier phase change rate, and carrier phase change acceleration control parameters to simulate the Doppler change law of the carrier with movement; The satellite navigation real-time signal generation unit multiplies the spread spectrum code baseband signal with the carrier signal to obtain a baseband signal with Doppler effect, which is then transmitted to the indoor satellite navigation receiver by wired or wireless radiation after digital-to-analog conversion and up-conversion to the navigation frequency band; The satellite navigation real-time signal generation unit outputs 1PPS and real-time time information to the indoor satellite navigation receiver to assist the satellite navigation receiver in directly capturing and receiving the authorization signal; The indoor satellite navigation receiver supports the direct capture and reception capability of the authorization signal using the approximate time information sent by the satellite navigation real-time signal generation unit; The indoor satellite navigation receiver sends the real-time navigation and positioning results to the motion controller for the motion controller to implement closed-loop dynamic control; Figure 2 This is a schematic diagram of the first implementation of the outdoor navigation signal purification unit of the present invention; this implementation adopts a digital multi-beam phased array antenna with an antenna gain of not less than 20dBi; each oscillator is followed by an independent radio frequency channel and an analog-to-digital converter AD; the digital sampling signals of all oscillators enter the digital beamforming unit, and beam synthesis of not less than 16 satellites is performed to obtain a digital sampling stream with the same number of satellites; the signal processing unit estimates all the civil and authorized signal spread spectrum codes contained in the frequency point from the digital sampling stream, and converts the estimated results into a high-speed data stream in a specific format and sends it through an optical fiber interface; Figure 3 This is a schematic diagram of a second embodiment of an outdoor navigation signal purification unit of the present invention; this embodiment uses a high-gain parabolic antenna array with the same number (not less than 16) as the number of satellites to be processed, and the antenna gain is not less than 20dBi; each parabolic antenna is equipped with an independent radio frequency channel and analog-to-digital converter AD; the digital sampling signals of all antennas enter the signal processing unit, and the signal processing unit estimates all civil and authorized signal spread spectrum codes contained in the frequency point from the digital sampling stream, and converts the estimated result, the current real-time time, and all satellite ephemeris into a high-speed data stream in a specific format and sends it through an optical fiber interface; Figure 4The present invention is a schematic diagram of a satellite navigation signal generation process according to an embodiment of the present invention; a real-time closed-loop simulation system obtains real-time time, all satellite ephemeris and real-time code stream estimation from an outdoor signal purification unit, and obtains real-time simulation trajectory parameters from a motion controller; a true range calculation algorithm of a conventional satellite navigation simulator is run using satellite ephemeris, real-time trajectory and time to obtain a sequence of true range changes with simulation sampling time; parameters such as true range and true range change rate are converted into control parameter information such as code and carrier phase, Doppler and high-order Doppler change rate according to the simulated navigation signal frequency and chip rate; generally, in a high-dynamic scenario, the parameter control information ranges from 100 Hz to 2000 Hz, and the faster the control parameter iteration, the higher the signal generation accuracy; a signal generation unit calculates the chip phase in real time in each iteration cycle, and queries the corresponding chip value from the real-time code stream estimation according to the chip phase; the real-time query chip value is used as a generated chip parameter of the navigation signal, and the code Doppler and carrier Doppler are modulated according to the navigation signal modulation mode of interest, and a navigation signal is generated and sent; Figure 5 The figure is a schematic diagram of the relationship between time synchronization and transmission of an embodiment of the present invention; the simulation time of the real-time closed-loop satellite navigation simulation system of the present invention can only sample the current time, or simulate the past time with the same time as the stored code stream based on the method of storing the real-time estimated code stream, and cannot simulate the future time; when performing a simulation synchronized with the current real-time time, the time transmission relationship is as shown in the figure; first, the satellite navigation purification unit, the satellite navigation real-time signal generation unit, the satellite navigation signal parameter simulation unit, and the motion controller all perform homologous operation based on the 10M and 1PPS signals provided by the same time-frequency reference; the navigation signal purification unit obtains the current real-time time t from the outdoor satellite navigation signal, and transmits the information to the satellite navigation real-time signal generation unit by optical fiber; the satellite navigation real-time signal generation unit transmits the real-time time t to the satellite navigation signal parameter simulation unit by an internal communication bus, such as a Gigabit network port, a 10G optical fiber network port, and other low-latency methods, and the satellite navigation signal parameter simulation unit feeds back the time to the motion controller in a low-latency manner by an interrupt or broadcast method of the optical fiber reflection memory, so that the simulation trajectory clock of the motion controller is synchronized with the current real-time time; Figure 6 Schematic diagram of real-time satellite navigation signal generation according to an embodiment of the present invention; inside the satellite navigation real-time signal generation unit, true range, true range change rate, and true range quadratic change rate parameters of 100 to 2000 Hz are received; -1Represents the unit delay link; taking the 100Hz update frequency as an example, within 10ms, the cumulative estimation of the true distance is realized by means of a digital integrator at a rate not less than twice the code chip clock. Usually, this part can be realized by using a cascaded numerically controlled oscillator inside the FPGA; taking the B3Q signal at the B3 frequency point as an example, the carrier frequency is 1268.52MHz, and the code rate is 10.23MHz. According to the real-time accumulated true distance, divided by the code and carrier wavelength, the real-time code and carrier phase can be obtained; according to the real-time code phase, the estimate of the B3Q code chip can be obtained from the real-time code stream estimate; according to the carrier phase, the real-time orthogonal carrier that simulates Doppler can be obtained; the real-time baseband B3Q signal with Doppler effect can be obtained by multiplying the real-time orthogonal carrier and the B3Q signal, and the real-time B3Q RF signal can be obtained by subsequent conventional up-conversion and filtering for reception and processing by the authorized navigation receiver.

[0012] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A real-time closed-loop satellite navigation simulation system, characterized in that: The system includes an outdoor navigation signal purification unit and an indoor real-time closed-loop simulation system; The outdoor navigation signal purification unit is connected to the indoor real-time closed-loop simulation system via an optical fiber link; The outdoor navigation signal purification unit includes a high-gain antenna and a signal processing system for real-time tracking of navigation satellites and extracting signal parameters; The indoor real-time closed-loop simulation system comprises a motion controller, a satellite navigation receiver and a real-time closed-loop satellite navigation simulator; the real-time closed-loop satellite navigation simulator comprises a satellite navigation signal parameter simulation unit and a satellite navigation real-time signal generation unit; The motion controller communicates with the satellite navigation signal parameter simulation unit through an optical fiber reflection memory; and the satellite navigation real-time signal generation unit transmits a simulation signal to the satellite navigation receiver.

2. A real-time closed-loop satellite navigation simulation system according to claim 1, characterized in that: The high-gain antenna is used to track no less than N navigation satellites in real time and digitally sample the frequency band of interest; wherein N is a positive integer representing the minimum number of navigation satellites tracked by the high-gain antenna in real time; The high-gain antenna is composed of a digital multi-beam active phased array antenna or a high-gain passive antenna having the same number as the number of navigation satellites being tracked; the gain is not less than a preset gain.

3. A real-time closed-loop satellite navigation simulation system according to claim 2, characterized in that: The signal processing system performs signal processing on the digital sampling stream of each navigation satellite, obtains real-time estimation of the spread spectrum code bits of the civil signal and the authorized signal in the same frequency band, completes conventional navigation positioning solution based on the civil signal in the navigation frequency band of interest, outputs the current real-time time, all satellite ephemeris parameters and code bit estimation results to the optical fiber link, and transmits them to the satellite navigation real-time signal generation unit.

4. A real-time closed-loop satellite navigation simulation system according to claim 3, characterized in that: The satellite navigation real-time signal generating unit receives the real-time time, ephemeris parameters and chip estimation results from the optical fiber link, and synchronizes the real-time time to the satellite navigation signal parameter emulation unit; the satellite navigation signal parameter emulation unit synchronizes the real-time time to the motion controller; The motion controller dynamically adjusts the motion trajectory in real time according to the real-time position data received by the satellite navigation receiver and the preset motion strategy; The motion controller generates position, velocity and acceleration information including a time stamp, and sends the information to the satellite navigation signal parameter simulation unit through an optical fiber reflection memory.

5. A real-time closed-loop satellite navigation simulation system according to claim 4, characterized in that: The satellite navigation signal parameter simulation unit calculates the transmission distance and change speed of the satellite navigation signal based on the received real-time ephemeris parameters and motion parameters, converts them into corresponding control parameters: pseudorange, carrier phase, phase change rate and phase change acceleration, and sends the control parameters to the satellite navigation real-time signal generation unit in real time.

6. A real-time closed-loop satellite navigation simulation system according to claim 5, characterized in that: The satellite navigation real-time signal generating unit calculates the real-time phase of the authorized navigation signal spread spectrum code simulated by the pseudorange, uses phase addressing to find the estimated value of the authorized signal spread spectrum code chip from the real-time estimated spread spectrum code stream, and iteratively generates authorized and unauthorized spread spectrum code baseband signals based on the pseudorange change rate and the change acceleration, and turns off some of the authorized or unauthorized spread spectrum code components according to the simulation scenario settings.

7. A real-time closed-loop satellite navigation simulation system according to claim 6, characterized in that: The satellite navigation real-time signal generating unit iteratively generates a corresponding carrier signal according to the control parameters: carrier phase, phase change rate and phase change acceleration, and simulates the Doppler change law of the carrier with movement; the satellite navigation real-time signal generating unit multiplies the spread spectrum code baseband signal with the carrier signal to obtain a baseband signal with Doppler effect, and after digital-to-analog conversion and up-conversion to the navigation frequency band, transmits it to the satellite navigation receiver in a wired or wireless radiation manner.

8. A real-time closed-loop satellite navigation simulation system according to claim 7, characterized in that: The satellite navigation real-time signal generating unit outputs a 1PPS signal and real-time time information to the satellite navigation receiver, so as to assist the satellite navigation receiver in directly capturing and receiving the authorization signal.

9. A real-time closed-loop satellite navigation simulation system according to claim 8, characterized in that: The satellite navigation receiver uses the approximate time information sent by the satellite navigation real-time signal generating unit to directly capture and receive the authorization signal; indoor The satellite navigation receiver sends the real-time navigation positioning results to the motion controller for the motion controller to implement closed-loop dynamic control.

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