A satellite navigation receiver data direct capture test method

Abstract

The present invention discloses a method for testing direct data capture of a satellite navigation receiver, relating to the field of satellite navigation technology. The method utilizes a high-gain multi-beam antenna to receive a marker-band navigation signal; performs chip-by-chip estimation of the dedicated code signal component; performs navigation positioning reception of the universal code signal component to obtain real-time time; provides approximate time synchronization to the receiver under test; remodulates and transmits the dedicated code signal using estimated chips; and evaluates the dedicated code direct capture performance based on the receiver's reception status. This method addresses the issues of dedicated code signals being unable to be directly generated in a ground test environment due to lack of authorization, and universal code signals at the same frequency being unable to be separated using non-regenerative transponders, thereby avoiding management risks.

Description

Technical Field

[0001] The invention relates to the technical field of satellite navigation, in particular to a method for directly capturing and testing satellite navigation receiver data. Background Art

[0002] The global satellite navigation system is currently one of the primary technologies for navigation, positioning, and timing. Compared to systems like inertial navigation and atomic clocks, it offers advantages such as stable error accumulation over time and all-weather, all-day operation. This has led to its widespread application in the universal code field. The structure of universal code satellite navigation signals is completely public, while dedicated code satellite navigation signals operating on the same frequency are long, periodless codes with anti-spoofing capabilities. To achieve this anti-spoofing capability for dedicated code signals, receivers must utilize direct dedicated code acquisition technology. This strategy cannot be employed, as it first receives the universal code signal and then uses the time signal carried by the universal code to guide acquisition of the dedicated code. This strategy can lead to failure in acquiring the dedicated code if the universal code is spoofed due to its public structure. Therefore, in satellite navigation testing, it is necessary to verify that the receiver is utilizing a direct dedicated code acquisition strategy.

[0003] Because the dedicated code is a satellite-encrypted signal, ground test equipment does not have a common generative simulator like the universal code. If the receiver uses guided capture, there is a probability that it will be guided to the wrong universal code signal time, resulting in guided capture failure. This method has uncertainty about how to control the power of the universal code signal to increase the error time. Excessive power can easily increase noise, and too little power may cause the receiver to successfully capture through normal universal code signal guidance, making it impossible to distinguish between guided capture and direct capture.

[0004] Therefore, the present invention discloses a satellite navigation receiver data direct capture test method to solve the above problems. Summary of the Invention

[0005] The object of the present invention is to provide a satellite navigation receiver data direct capture test method to solve the problems raised in the prior art.

[0006] To achieve the above object, the present invention provides the following technical solution: This method is divided into the following steps:

[0007] S1. Use a high-gain multi-beam antenna to receive the navigation signal in the marked frequency band;

[0008] The high-gain multi-beam antenna system amplifies and filters the navigation signal of each satellite and performs analog-to-digital conversion to generate a digital signal stream corresponding to the number of satellites.

[0009] The high-gain multi-beam antenna system includes a planar or spherical digital multi-beam phased array or a preset number of directional high-gain passive antennas; the digital multi-beam phased array is used to generate a preset number of digital beams and monitor satellites; each directional high-gain passive antenna monitors a satellite in real time through a motion servo mechanism.

[0010] S2. Perform chip-by-chip estimation of the dedicated code signal component;

[0011] The sampled dedicated code signal components within the marked frequency band are estimated chip by chip to obtain real-time information of the dedicated code aperiodic code stream.

[0012] S3. Navigation and positioning reception of universal code signal components to obtain real-time time;

[0013] Perform navigation positioning and timing calculation on the universal code signal components sampled in the marked frequency band to obtain the current real-time time information.

[0014] S4. Perform approximate time synchronization on the receiver under test;

[0015] The current time information after adjustment and deviation is transmitted to the receiver under test through the external timing input interface that can be recognized by the receiver under test;

[0016] The timing information is equal to or lags behind the timing parameters of the current real-time time; when the timing time lags behind the current real-time time, the dedicated code chip information is synchronously triggered to cache processing within a certain time range according to the lag amount of the current timing time compared to the real-time time, so as to generate a signal different from the time delay corresponding to the current actual estimated chip during the remodulation process, that is, to change the positioning result of the receiver under test corresponding to the remodulated signal.

[0017] The external timing input interface adopts a combination architecture of 1PPS signal and at least one communication interface, and the communication interface includes any one of RS232, RS422 or network port communication interface.

[0018] S5. The dedicated code signal is remodulated and transmitted using the estimated chip;

[0019] According to the navigation signal format of the marked frequency band, the dedicated code signal component is remodulated based on the pre-stored estimated code chip, while the universal code signal component is kept unmodulated, ensuring that the receiver under test cannot receive the universal code signal component, preventing the receiver under test from completing the acquisition and tracking of the dedicated code signal through guided acquisition;

[0020] When the timing time lags behind the real time, the cached special code chip estimation value is called to perform dynamic regeneration configuration according to the lag time parameter and the receiver special code direct capture time uncertainty parameter, so that the time information carried by the regenerated special code and the timing time of the tested receiver do not exceed the special code direct capture time uncertainty threshold;

[0021] After the regenerated dedicated code signal is loaded onto a carrier and modulated, it is sent to the receiver under test through a wired transmission channel or a controlled wireless radiation device. When wireless radiation is used, the receiver under test is placed in an electromagnetic shielding environment to block the reception of the original satellite navigation signal.

[0022] S6. Evaluate the dedicated code direct capture performance according to the reception status of the receiver under test;

[0023] The receiver under test receives the externally input approximate time information and regenerates the dedicated code signal and then performs navigation and positioning processing;

[0024] When the receiver under test completes dedicated code acquisition monitoring and outputs a normal positioning timing result, determining that it adopts the dedicated code direct acquisition mode;

[0025] When the receiver under test is unable to normally demodulate the dedicated code signal under the condition that the approximate timing error meets the design index, it is determined that the receiver has at least one abnormal state of failure in capturing the dedicated code guided by the universal code, key expiration, or hardware failure;

[0026] By setting the difference between the timing time and the regeneration signal broadcasting time, the dedicated code direct capture time of the receiver under test is tested under the specified time error, and its direct capture performance and efficiency are evaluated according to the capture time parameters.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows: the dedicated code direct capture test method proposed in this article solves the problem that dedicated code signals cannot be directly generated in a ground test environment due to lack of authorization, and that universal code signals at the same frequency point cannot be separated using a non-regenerative repeater. A test environment and method with only dedicated code signals is constructed, thereby directly testing whether the receiver under test uses the dedicated code direct capture method. The method has the advantages of being intuitive and unambiguous, and not requiring the addition of additional auxiliary signals.

[0028] For direct capture of dedicated codes, a test stimulus signal can be constructed containing only dedicated code components, without any universal code signal components. This avoids the complexity of adding an auxiliary, error-timed universal code signal required by other methods. The entire testing process does not require prior knowledge of the satellite navigation system's authorization information and is compatible with all navigation signals, including GPS and the BeiDou-3 satellite navigation system. This approach offers a wide range of applications and mitigates regulatory risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0030] Figure 1 A schematic flow chart of a satellite navigation receiver data direct capture test method according to the present invention;

[0031] Figure 2 A schematic diagram of the BeiDou-3 B1 frequency band signal spectrum for a satellite navigation receiver direct data capture test method according to the present invention;

[0032] Figure 3 This is a schematic diagram of the system structure of a satellite navigation receiver data direct capture test method of the present invention;

[0033] Figure 4 This is a schematic structural diagram of an outdoor navigation signal purification unit of a satellite navigation receiver data direct capture test method of the present invention;

[0034] Figure 5 A schematic diagram of the relationship between timing, chip buffering and regeneration time in a satellite navigation receiver data direct capture test method of the present invention;

[0035] Figure 6 The figure is a schematic diagram of the test result analysis of a satellite navigation receiver data direct capture test method according to the present invention. DETAILED DESCRIPTION

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0037] See also Figure 1 The present invention provides a technical solution: a satellite navigation receiver data direct capture test method, the method comprising the following steps:

[0038] S1. Use a high-gain multi-beam antenna to receive the navigation signal in the marked frequency band;

[0039] The high-gain multi-beam antenna system amplifies and filters the navigation signal of each satellite and performs analog-to-digital conversion to generate a digital signal stream corresponding to the number of satellites.

[0040] The high-gain multi-beam antenna system includes a planar or spherical digital multi-beam phased array or a preset number of directional high-gain passive antennas; the digital multi-beam phased array is used to generate a preset number of digital beams and monitor satellites; each directional high-gain passive antenna monitors a satellite in real time through a motion servo mechanism.

[0041] In this embodiment, a high-gain antenna of the BeiDou-3 B1 frequency band is used to perform analog-to-digital conversion on all signals within a bandwidth of not less than 32.736 MHz.

[0042] S2. Perform chip-by-chip estimation of the dedicated code signal component;

[0043] The sampled dedicated code signal components within the marked frequency band are estimated chip by chip to obtain real-time information of the dedicated code aperiodic code stream.

[0044] In this embodiment, real-time demodulation estimation is performed on each chip of the BOC (14, 2) modulation mode of the BeiDou-3 B1A signal. The real-time demodulation estimation means separating each chip data of the B1A signal from the broadband signal of the marker frequency band.

[0045] S3. Navigation and positioning reception of universal code signal components to obtain real-time time;

[0046] Perform navigation positioning and timing calculation on the universal code signal components sampled in the marked frequency band to obtain the current real-time time information.

[0047] In this embodiment, navigation and positioning solutions are performed on the BeiDou-3 B1C and B1I signals to obtain the current real-time time information.

[0048] S4. Perform approximate time synchronization on the receiver under test;

[0049] Through the external timing input interface that can be recognized by the receiver under test, a certain amount of lag is added to the time information obtained from the universal code signal positioning solution to adjust the timing time, and the current time information after the adjustment is transmitted to the receiver under test;

[0050] The timing information is equal to or lags behind the timing parameters of the current real time; when the timing time lags behind the current real time, the cache processing of the dedicated code chip information is synchronously triggered.

[0051] The external timing input interface adopts a combination architecture of 1PPS signal and at least one communication interface, and the communication interface includes any one of RS232, RS422 or network port communication interface.

[0052] S5. The dedicated code signal is remodulated and transmitted using the estimated chip;

[0053] Based on the navigation signal format of the marked frequency band and the desired navigation signal characteristics, including the signal delay and signal frequency deviation of each satellite, the satellite signal delay represents the satellite pseudorange value, and the signal frequency deviation represents the satellite Doppler value; remodulating the dedicated code signal component based on the pre-stored estimated code chip, where remodulation means modulating the dedicated code into a carrier signal carrying the signal characteristics; while keeping the universal code signal component unmodulated;

[0054] When the timing time lags behind the real time, the cached special code chip estimation value is called to perform dynamic regeneration configuration according to the lag time parameter and the receiver special code direct capture time uncertainty parameter, so that the time information carried by the regenerated special code and the timing time of the tested receiver do not exceed the special code direct capture time uncertainty threshold;

[0055] After the regenerated dedicated code signal is loaded onto a carrier and modulated, it is sent to the receiver under test through a wired transmission channel or a controlled wireless radiation device. When wireless radiation is used, the receiver under test is placed in an electromagnetic shielding environment to block the reception of the original satellite navigation signal.

[0056] In this embodiment, the navigation signal regeneration unit uses the real-time estimated B1A chip information to perform regeneration modulation of the B1A signal and outputs the signal to the satellite navigation receiver under test.

[0057] S6. Evaluate the dedicated code direct capture performance according to the reception status of the receiver under test;

[0058] The receiver under test receives the externally input approximate time information and regenerates the dedicated code signal and then performs navigation and positioning processing;

[0059] When the receiver under test completes dedicated code acquisition monitoring and outputs a normal positioning timing result, determining that it adopts the dedicated code direct acquisition mode;

[0060] When the receiver under test cannot normally demodulate the special code signal under the condition that the approximate timing error meets the design index, it is determined that there is at least one abnormal state of failure of universal code to guide special code capture, key expiration or hardware failure.

[0061] See also Figure 2 , the present invention provides a technical solution:

[0062] This embodiment marks the B1 frequency band signal of the BeiDou-3 satellite navigation system. The universal code signals include the B1C signal with a center frequency of 1575.42 MHz and the B1I signal at 1561.098 MHz, as well as the dedicated code B1A signal. The dedicated code direct capture test of the BeiDou-3 receiver focuses on whether the receiver uses dedicated code direct capture of the B1A signal and the performance indicators of direct capture, including capture time and capture sensitivity.

[0063] See also Figure 3 , the present invention provides a technical solution:

[0064] The system consists of an outdoor navigation signal purification unit, an indoor dedicated code stream buffer unit, a navigation signal regeneration unit, a scenario configuration and evaluation unit, and a satellite navigation receiver under test.

[0065] The navigation signal purification unit, in this embodiment, uses a digital multi-beam phased array to purify and estimate the chip frequency of the BeiDou-3 B1 band signals from no fewer than 16 satellites. Specifically, the phased array can be planar, spherical, or of other shapes, forming no fewer than 16 beams simultaneously. It performs real-time beam pointing monitoring and chip frequency estimation based on the real-time positions calculated from the ephemeris broadcast by the BeiDou satellites.

[0066] The navigation signal purification unit estimates the B1A dedicated code stream in real time and sends it via optical fiber to the indoor dedicated code stream buffer unit for storage. The dedicated code stream buffer unit, based on the time information provided by the navigation signal regeneration unit, feeds back the dedicated code stream corresponding to the time index to the navigation signal regeneration unit.

[0067] The scenario configuration and evaluation unit configures the components, power and delay configuration of the generated navigation signal, and performs evaluation and analysis based on the working status reported by the satellite navigation receiver under test. The evaluation and analysis includes judging the capture, tracking, carrier-to-noise ratio or power calculation results of the dedicated code signal by the satellite navigation receiver under test, and whether the positioning and speed measurement results corresponding to the currently generated navigation signal are consistent with the characteristics of the currently generated navigation signal, so as to conduct a detailed evaluation of the functions and performance of the satellite navigation receiver under test.

[0068] The navigation signal regeneration unit queries the corresponding dedicated code information from the dedicated code stream cache unit in real time based on the scenario configuration parameters, and then uses the principle of the satellite navigation simulator to modulate the B1 frequency band B1A or B1A+B1C+B1I satellite navigation signal according to the configured delay and power.

[0069] The navigation signal regeneration unit provides the measured satellite navigation receiver with probabilistic timing information that differs from the real-time regenerated navigation signal time by a specified offset based on the timing error information configured in the scenario. The approximate time information is transmitted to the measured satellite navigation receiver using 1PPS, serial port, network port, etc.

[0070] The navigation signal regeneration unit connects the regenerated satellite navigation signal to the satellite navigation receiver under test by wired or wireless radiation.

[0071] The satellite navigation receiver under test receives the approximate time information and the regenerated navigation signal, performs the receiver capture monitoring operation, and reports the working status of the receiver to the scenario configuration and evaluation unit according to the agreed protocol. The reported information includes but is not limited to the satellite capture success flag, the captured satellite number, the carrier-to-noise ratio of each normally received satellite signal, the PVT positioning solution result, etc.

[0072] See also Figure 4 , the present invention provides a technical solution:

[0073] This implementation adopts a digital multi-beam phased array antenna with an antenna gain of not less than 20dBi. Each oscillator is equipped with an independent RF channel and analog-to-digital converter (ADC). The digital sampling signals of all oscillators are processed by a digital multi-beam forming algorithm, 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 the B1A authorization signal spread spectrum code contained in the frequency point from the digital sampling stream, obtains the serial estimated code stream corresponding to the spread spectrum code rate, and converts the estimated code stream into a parallel data stream according to the data format agreed with the indoor code stream cache unit and the navigation signal regeneration unit. The data streams of the 16 satellites are aggregated into a real-time data stream and sent through the optical fiber interface.

[0074] See also Figure 5 , the present invention provides a technical solution:

[0075] The authorization signal received by the navigation signal purification unit is processed in real time, carrying the current real-time information t. After passing through the dedicated code stream cache unit, it is read from the cache under the control of the configuration unit. The read code stream carries the time t-Δt1. The navigation signal regeneration unit remodulates the read code stream in real time and transmits it. The transmission signal also carries the time t-Δt1. The configuration unit sets the approximate timing deviation Δt2 and uses 1PPS and serial and network ports to time the navigation receiver under test. The actual timing error seen by the receiver is Δt1-Δt2. When this error is within the search capability range of the receiver's dedicated code direct capture, the receiver should be able to directly capture the regenerated navigation signal using the normal dedicated code, without the need to use the universal code to guide the dedicated code method, which has security risks.

[0076] See also Figure 6 , the present invention provides a technical solution:

[0077] The scenario configuration and evaluation unit first sets Δt1 and Δt2 to control the receiver's actual timing offset error, then receives the receiver's reported navigation status for protocol parsing. If acquisition is reported as successful, the receiver's dedicated code direct acquisition function and performance meet the requirements. If acquisition fails, the unit checks whether the timing offset error exceeds the designed value. If it does not exceed the receiver's nominal specifications, the receiver's dedicated code direct acquisition function fails. Otherwise, the unit's timing offset error is revised and retested.

[0078] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0079] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A satellite navigation receiver data direct capture test method, characterized in that: The method comprises the following steps: S1. Use an outdoor high-gain multi-beam antenna to receive the marked frequency band navigation signal; S2. chip-by-chip estimation of the dedicated code signal component in the marker band navigation signal; S3. Navigation and positioning reception of the universal code signal component in the navigation signal of the marking band to obtain real-time time; S4. Real-time time obtained based on the universal code signal component, the indoor receiver under test is roughly timed; S5. According to the navigation signal format of the marking band, the dedicated code signal is remodulated and transmitted with the estimated code chip; In S5, according to the navigation signal format of the marked frequency band, the dedicated code signal component is remodulated based on the pre-stored estimated chip, while the universal code signal component is kept in an unmodulated state; When the timing time lags behind the real time, the cached special code chip estimation value is called to perform dynamic regeneration configuration according to the lag time parameter and the receiver special code direct capture time uncertainty parameter, so that the time information carried by the regenerated special code and the timing time of the tested receiver do not exceed the special code direct capture time uncertainty threshold; After loading the regenerated dedicated code signal onto a carrier for modulation, it is sent to the receiver under test through a wired transmission channel or a controlled wireless radiation device; When wireless radiation is used, the receiver under test is placed in an electromagnetic shielding environment to block the reception of the original satellite navigation signal; S6. Evaluate the dedicated code direct capture performance based on the reception status of the indoor receiver under test.

2. The satellite navigation receiver data direct capture test method according to claim 1, characterized in that: In S1, the high-gain multi-beam antenna system amplifies and filters the navigation signal of each satellite and performs analog-to-digital conversion to generate a digital signal stream corresponding to the number of satellites.

3. The satellite navigation receiver data direct capture test method according to claim 2, characterized in that: The high-gain multi-beam antenna system includes a planar or spherical digital multi-beam phased array or a preset number of directional high-gain passive antennas; the digital multi-beam phased array is used to generate a preset number of digital beams and monitor satellites; each directional high-gain passive antenna monitors a satellite in real time through a motion servo mechanism.

4. The satellite navigation receiver data direct capture test method according to claim 1, characterized in that: In S2, the sampled dedicated code signal components within the marked frequency band are estimated chip by chip to obtain real-time information of the dedicated code aperiodic code stream.

5. The satellite navigation receiver data direct capture test method according to claim 1, characterized in that: In S3, navigation positioning and timing calculation are performed on the sampled universal code signal components in the marker frequency band to obtain the current real-time time information.

6. The satellite navigation receiver data direct capture test method according to claim 1, characterized in that: In S4, the current time information after the adjustment is transmitted to the receiver under test through the external timing input interface that can be recognized by the receiver under test; The timing information is equal to or lags behind the timing parameters of the current real time; when the timing time lags behind the current real time, the cache processing of the dedicated code chip information is synchronously triggered.

7. The satellite navigation receiver data direct capture test method according to claim 6, characterized in that: The external timing input interface adopts a combination architecture of 1PPS signal and at least one communication interface, and the communication interface includes any one of RS232, RS422 or network port communication interface.

8. The satellite navigation receiver data direct capture test method according to claim 1, characterized in that: In S6, the receiver under test receives the externally input approximate time information and the regenerated dedicated code signal and then performs navigation and positioning processing; When the receiver under test completes dedicated code acquisition monitoring and outputs a normal positioning timing result, determining that it adopts the dedicated code direct acquisition mode; When the receiver under test is unable to normally demodulate the dedicated code signal under the condition that the approximate timing error meets the design index, it is determined that the receiver has at least one abnormal state of failure in capturing the dedicated code guided by the universal code, key expiration, or hardware failure; By setting the difference between the timing time and the regeneration signal broadcasting time, the dedicated code direct capture time of the receiver under test is tested under the specified time error, and its direct capture performance and efficiency are evaluated according to the capture time parameters.

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