A satellite signal acquisition method, apparatus, system, and storage medium
By utilizing the NH code stripping method in satellite signal acquisition, coherent integration results are obtained from the Doppler code phase position and incoherent integration analysis is performed, solving the problem of low acquisition success rate in weak signal environments and achieving fast and efficient satellite signal acquisition.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- WUHAN MENGXIN TECH CO LTD
- Filing Date
- 2023-09-14
- Publication Date
- 2026-07-31
AI Technical Summary
In weak signal environments, traditional satellite signal acquisition algorithms struggle to effectively capture satellite signals, resulting in a low success rate and excessively long processing times.
By obtaining coherent integration results from the Doppler code phase position, analyzing incoherent integration results using NH code, and filtering the results, NH code stripping is achieved, thereby improving acquisition sensitivity and speed.
It accelerates the acquisition and processing speed of satellite signals and improves the sensitivity of satellite signal acquisition, especially significantly increasing the success rate of acquisition in weak signal environments.
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Figure CN117420577B_ABST
Abstract
Description
Technical Field
[0001] This invention relates primarily to the field of satellite navigation technology, specifically to a satellite signal acquisition method, apparatus, system, and storage medium. Background Technology
[0002] In a Global Navigation Satellite System (GNSS) receiver, acquisition is the first crucial step in signal processing. Before initiating signal tracking, the receiver needs to estimate two parameters: the carrier frequency and the code phase of the received signal. Then, based on these estimates, the tracking loop is initialized to assist the receiving channel in tracking the signal. The purpose of signal acquisition is precisely to obtain rough estimates of the carrier frequency and code phase of all visible satellite signals.
[0003] However, in real-world environments, GNSS receivers are widely used in weak signal conditions, such as indoors or in forests. In these environments, the carrier-to-noise ratio (CNR) of satellite signals is about 20 dB lower than in open outdoor environments. Traditional acquisition algorithms struggle to capture these weak signals; therefore, it is necessary to improve the sensitivity of software-defined receivers for weak signal acquisition.
[0004] Generally, weak signal acquisition algorithms that improve sensitivity involve extending the integration time. Methods for extending the integration time include coherent integration and incoherent integration. Coherent integration involves directly accumulating the integrated results of the signal after matched filtering for every 1 ms over multiple milliseconds. Incoherent integration, on the other hand, involves accumulating the amplitudes of multiple coherent integration results. Incoherent integration suffers from squared loss; the lower the signal-to-noise ratio (SNR) of the signal after coherent integration, the higher the squared loss. Therefore, to reduce squared loss, it is necessary to obtain a higher coherent integration SNR, and extending the coherent integration time is the most obvious way to achieve this.
[0005] According to the maximum likelihood criterion, extending the coherent integration time is the most effective way to improve acquisition sensitivity. However, navigation data consists of symbol transitions, which limits the coherent integration time. The current GPS message data rate is 50 bits / s, meaning that a bit symbol transition may occur every 20 ms. When the bit start position is unknown, the coherent integration time cannot exceed 20 ms.
[0006] For BDS B1I and B3I non-GEO satellite signals, the unit data rate is also 50 bits / s. However, within the 20ms period corresponding to one data bit, the level does not remain in the same phase. Instead, an NH code is modulated within each 20ms data bit period. Each symbol of the NH code has a period of 1ms and a length of 20ms, with the start and reception times strictly corresponding to the start and end times of the data bits. If the exact start time of the NH code cannot be known, it is impossible to effectively strip the NH code. During multi-millisecond coherent integration, the integration result is affected by the NH code level flipping, leading to a significant decrease in integration gain.
[0007] On the other hand, finding the start time of the NH code means finding the start time of the 20ms message bits. By reasonably designing the integration time and the start time of integration, the impact of message bit flipping on the coherent integration gain can be minimized.
[0008] The commonly used NH code stripping method in receivers involves iteratively traversing the data within the acquisition memory (AEFIFO). This involves adding an NH code search layer to the normal Doppler-code phase two-dimensional grid search space for acquisition. First, it's assumed that the current data start corresponds to the first bit of the NH code, and NH stripping is performed accordingly. Then, a Doppler-code phase two-dimensional search is performed, and the maximum value is saved. Next, it's assumed that the data start corresponds to the second bit of the NH code, and NH stripping is performed again. Then, a Doppler-delay two-dimensional search is performed, and the maximum value is compared with the previously saved maximum value, saving the larger one… This process is repeated 20 times, completing the traversal of the initial NH code position. The maximum value from the 20 two-dimensional search results is obtained, and the acquisition decision is entered, transitioning to tracking. This method achieves NH code stripping by assuming the initial time corresponds to all possible NH code positions. Correct NH code stripping is only achieved when the assumed NH code position at the initial time matches the actual position, at which point the integral result is maximized.
[0009] The above method for stripping NH codes has the advantage that the processing logic is basically similar to GPS, requiring almost no additional storage units. However, it increases the computational load of the Doppler-code phase two-dimensional search operation by twenty times, resulting in a 20-fold increase in processing time. When the satellite signal is strong, a short integration time is sufficient to achieve a adequate incoherent integrated signal-to-noise ratio (SNR), leading to a high success rate for a single acquisition. In this case, the 20-fold increase in processing time is not noticeable. However, when the signal is weak, a sufficiently long integration time is required to significantly improve the incoherent integrated SNR. In this case, the success rate for a single acquisition may be relatively low, necessitating multiple acquisition attempts to increase the final success rate. Within the specified timeframe, a 20-fold increase in processing time for each BDS satellite leads to a 20-fold decrease in the number of acquisition attempts, resulting in a significant drop in the final success rate. Summary of the Invention
[0010] The technical problem to be solved by the present invention is to provide a satellite signal acquisition method, apparatus, system and storage medium to address the shortcomings of the prior art.
[0011] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A satellite signal acquisition method, comprising the following steps:
[0012] S1: Obtain the original coherent integral results of multiple initial NH code positions from any one of the multiple original Doppler code phase positions;
[0013] S2: Import the NH code, analyze the incoherent integration results of multiple original coherent integration results corresponding to the phase position of the original Doppler code according to the NH code, obtain the target incoherent integration result, and return to S1, until all the multiple original coherent integration results corresponding to the phase position of the original Doppler code have been analyzed, thereby obtaining the target incoherent integration result corresponding to each phase position of the original Doppler code.
[0014] S3: Filter all the original coherent integration results and all the target incoherent integration results to select the satellite signal acquisition results.
[0015] Another technical solution of the present invention to solve the above-mentioned technical problems is as follows: A satellite signal acquisition device, comprising:
[0016] The coherent integration result acquisition module is used to obtain the original coherent integration results of multiple initial NH code positions from any one of the multiple original Doppler code phase positions;
[0017] The import module is used to import NH codes;
[0018] The analysis module is used to analyze the non-coherent integration results of multiple original coherent integration results corresponding to the phase position of the original Doppler code based on the NH code, obtain the target non-coherent integration result, and return to the coherent integration result acquisition module until all the multiple original coherent integration results corresponding to the phase position of the original Doppler code have been analyzed, thereby obtaining the target non-coherent integration result corresponding to each phase position of the original Doppler code.
[0019] The acquisition result acquisition module is used to filter all the original coherent integration results and all the target incoherent integration results to select the satellite signal acquisition results.
[0020] Based on the above-described satellite signal acquisition method, the present invention also provides a satellite signal acquisition system.
[0021] Another technical solution of the present invention to solve the above-mentioned technical problems is as follows: a satellite signal acquisition system, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the satellite signal acquisition method as described above.
[0022] Based on the above-described satellite signal acquisition method, the present invention also provides a computer-readable storage medium.
[0023] Another technical solution of the present invention to solve the above-mentioned technical problems is as follows: a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the satellite signal acquisition method as described above.
[0024] The beneficial effects of this invention are as follows: by obtaining the original coherent integration result from the original Doppler code phase position, and analyzing the non-coherent integration result of the original coherent integration result based on the NH code, the target non-coherent integration result is obtained. By filtering the original coherent integration result and the target non-coherent integration result, the satellite signal acquisition result is selected, thus realizing NH code stripping, accelerating the satellite signal acquisition and processing speed, and improving the sensitivity of satellite signal acquisition. Attached Figure Description
[0025] Figure 1 This is a flowchart illustrating a satellite signal acquisition method provided in an embodiment of the present invention;
[0026] Figure 2 This is a schematic diagram of NH code stripping in a satellite signal acquisition method provided by an embodiment of the present invention;
[0027] Figure 3 This is a schematic diagram of secondary encoding for a satellite signal acquisition method provided in an embodiment of the present invention;
[0028] Figure 4 This is a block diagram of a satellite signal acquisition device provided in an embodiment of the present invention. Detailed Implementation
[0029] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.
[0030] Figure 1 This is a flowchart illustrating a satellite signal acquisition method provided in an embodiment of the present invention.
[0031] like Figure 1 As shown, a satellite signal acquisition method includes the following steps:
[0032] S1: Obtain the original coherent integral results of multiple initial NH code positions from any one of the multiple original Doppler code phase positions;
[0033] S2: Import the NH code, analyze the incoherent integration results of multiple original coherent integration results corresponding to the phase position of the original Doppler code according to the NH code, obtain the target incoherent integration result, and return to S1, until all the multiple original coherent integration results corresponding to the phase position of the original Doppler code have been analyzed, thereby obtaining the target incoherent integration result corresponding to each phase position of the original Doppler code.
[0034] S3: Filter all the original coherent integration results and all the target incoherent integration results to select the satellite signal acquisition results.
[0035] It should be understood that the number of original coherent integral results for multiple initial NH code positions can be 20.
[0036] Specifically, filtering all the original coherent integration results and all the target incoherent integration results to select satellite signal acquisition results means using the selected results as satellite signal acquisition results.
[0037] It should be understood that the coherent integration result of 1ms (i.e., the original coherent integration result) is copied 20 times, corresponding to different positions of the NH code (i.e., the initial NH code positions).
[0038] Specifically, the original coherent integration result is the coherent integration result of 1ms. The original coherent integration result is the result of a commonly used method for GNSS baseband signal processing. Specifically, it is implemented as follows: for the 1ms sampling data, the local NCO generates a pseudocode copy with the same sampling rate, multiplies the two points by point, and accumulates the results. The final accumulated result is the 1ms coherent integration result, which is in complex number form.
[0039] It should be understood that the NH code is cyclically shifted every 1ms until the number of incoherent integrations reaches a threshold (i.e. until all the original coherent integration results corresponding to the original Doppler code phase positions have been analyzed).
[0040] In the above embodiments, the original coherent integration result is obtained from the original Doppler code phase position, and the target incoherent integration result is obtained by analyzing the incoherent integration result of the original coherent integration result based on the NH code. The satellite signal acquisition result is selected by filtering the original coherent integration result and the target incoherent integration result, thus realizing NH code stripping, accelerating the satellite signal acquisition and processing speed, and improving the sensitivity of satellite signal acquisition.
[0041] Optionally, as an embodiment of the present invention, such as Figures 1 to 3 As shown, in step S2, the process of importing the NH code and analyzing the incoherent integration results of multiple original coherent integration results corresponding to the phase positions of the original Doppler code based on the NH code to obtain the target incoherent integration result includes:
[0042] S21: Import the NH code, and perform NH code stripping processing on each original coherent integration result corresponding to the phase position of the original Doppler code according to the NH code, to obtain the stripped coherent integration result corresponding to each original coherent integration result.
[0043] S22: Sum all the stripped coherent integration results to obtain the coherent integration result to be processed, and return to S21 until the preset number of iterations is reached, thereby obtaining multiple coherent integration results to be processed;
[0044] S23: Summate all the coherent integral results to be processed to obtain the target incoherent integral result.
[0045] It should be understood that, for the 20 1ms coherent integration results (i.e., the original coherent integration results), NH code stripping is performed according to their respective NH code positions.
[0046] Specifically, such as Figure 2 As shown, the coherent integration results (a1, a2, a3…) of consecutive 1ms intervals are copied 20 times, each corresponding to a different NH phase start position, denoted as N1 to N20. Then, NH code stripping is performed on each of these start positions, represented by multiplying by b1 to b20. The NH code position corresponding to the integration result of the next 1ms interval is shifted one bit to the right accordingly. By repeating this operation, the NH code stripping of all 1ms coherent integration results can be completed. In this process, the 1ms coherent integration, which has the longest processing time, is performed only once, thus effectively reducing the processing time.
[0047] It should be understood that the real and imaginary parts of the result after stripping the NH code (i.e. the result of the coherent integration after stripping) are added to the cumulative result of the coherent integration (i.e. the result of the coherent integration to be processed), and the number of coherent integrations is incremented by 1 until the number of coherent integrations reaches the preset value N_coh (i.e. the preset number of iterations).
[0048] Specifically, the addition of the real and imaginary parts to the coherent integration accumulation result (i.e., the coherent integration result to be processed) refers to the coherent integration of multiple 1ms data (i.e., the coherent integration result after stripping) to obtain multiple complex numbers. These multiple complex numbers are then directly added together, that is, all real parts are added together, and then all imaginary parts are added together to obtain the real and imaginary parts of the accumulation result (i.e., the coherent integration result to be processed).
[0049] In the above embodiments, the target incoherent integral result is obtained by analyzing the incoherent integral result of the original coherent integral result based on the NH code. This effectively reduces the processing time, realizes the stripping of the NH code, accelerates the acquisition and processing speed of satellite signals, and also improves the sensitivity of satellite signal acquisition.
[0050] Optionally, as an embodiment of the present invention, such as Figure 1 As shown, the process of S23 includes:
[0051] Extract the coherent integral amplitude corresponding to each of the coherent integral results to be processed from each of the coherent integral results to be processed;
[0052] The target incoherent integral result is obtained by summing all the coherent integral amplitudes.
[0053] It should be understood that the complex data in the coherent integration accumulation result (i.e. the coherent integration result to be processed) are taken as amplitudes and added to the incoherent accumulation result (i.e. the target incoherent integration result). The coherent integration count is cleared to zero and the incoherent integration count is incremented by 1.
[0054] Specifically, for the complex coherent integral result of the form I+jQ, the amplitude result is taken as sqrt(I*I+Q*Q), which is a positive real number. The amplitudes of multiple coherent integral results are added together, which is the incoherent accumulation (i.e. the target incoherent integral result).
[0055] It should be understood that the target incoherent integration result refers to the multi-millisecond coherent integration result. After taking the amplitude, it is the result of one incoherent integration. The positive real numbers obtained from multiple incoherent integrations are directly added together to obtain the incoherent accumulation (i.e., the target incoherent integration result).
[0056] In the above embodiments, the coherent integral amplitude is extracted from each coherent integral result to be processed, and the target incoherent integral result is obtained by summing all the coherent integral amplitudes. This effectively reduces the processing time, speeds up the acquisition and processing of satellite signals, and also improves the sensitivity of satellite signal acquisition.
[0057] Optionally, as an embodiment of the present invention, the process of S3 includes:
[0058] The maximum value among all the target incoherent integration results is selected, and the maximum target incoherent integration result is obtained. The original Doppler code phase position corresponding to the maximum target incoherent integration result is taken as the target Doppler code phase position.
[0059] The maximum value among all raw coherent integration results corresponding to the target Doppler code phase position is selected, and the maximum raw coherent integration result is obtained. The initial NH code position corresponding to the maximum raw coherent integration result is taken as the target NH code position, and the target Doppler code phase position and the target NH code position are taken as the satellite signal acquisition result.
[0060] It should be understood that the data of different Doppler-code phases (i.e., the original Doppler code phase positions) and NH initial positions (i.e., the initial NH code positions) are compared, and the maximum value is taken as the capture result.
[0061] Specifically, the acquisition process requires setting a Doppler-code phase position each time before coherent and incoherent integration can be performed. The incoherent integration result is the acquisition result for a hypothetical point, while the acquisition results for multiple Doppler-code phase configurations are the frequency-phase search results within a preset search range. The initial NH position is the initial NH phase value corresponding to each of the 20 copies of data in step 1 (i.e., S1) (i.e., initializing the NH code position). Due to the special characteristics of the NH code in the modulation of BDS non-GEO signals, its acquisition is a three-dimensional search process of Doppler-code phase and NH phase.
[0062] In the above embodiments, all original coherent integration results and all target incoherent integration results are filtered to select satellite signal acquisition results, thereby realizing NH code stripping, accelerating the satellite signal acquisition and processing speed, and improving the sensitivity of satellite signal acquisition.
[0063] Optionally, as another embodiment of the present invention, for B1I and B3I signals containing NH code secondary encoding in BeiDou signals, the present invention uses the NH cyclic traversal method to strip the NH code, thereby accelerating the acquisition speed of BeiDou signals and improving the acquisition sensitivity.
[0064] Optionally, as another embodiment of the present invention, since the D1 navigation message data bits of B1I and B3I in the BDS system are modulated with NH code (00000100110101001110), this secondary encoding changes the level duration from 20ms to 1ms. If the starting edge of the 20ms message data bit cannot be found, the NH code cannot be effectively stripped. When performing coherent integration for more than 1ms, gain loss may occur.
[0065] The commonly used NH code stripping method adds an NH code search layer to the original two-dimensional Doppler-code phase search in the acquisition process. This method is simple to implement and requires no additional storage space, but the processing time increases linearly. Assuming the original two-dimensional search acquisition processing time is T, after adding the NH code search, the processing time becomes 20T. This increase in processing time causes the total number of acquisition cycles N between units to become N / 20. Since the probability of a single successful acquisition of a weak signal satellite is very low, it is necessary to repeatedly initiate acquisition attempts on the same satellite to increase the final success probability. Reducing the number of acquisition attempts to 1 / 20 of the original significantly decreases the corresponding final success probability. In summary, the NH code cyclic stripping method reduces the acquisition sensitivity of BDS signals.
[0066] To improve the acquisition and processing speed of BDS and reduce the impact of NH codes on processing time, the following space-for-time trade-off method can be considered: For the 1ms coherent integration result, make 20 copies, each starting at a different phase of the NH code sequence. Subsequent coherent integration results are then despread using NH codes at different NH start times. The resulting incoherent integration result is also amplified by 20 times. Therefore, the number of time-consuming coherent and incoherent processing operations is reduced to 1 / 20 of the original, while only the processing of the 1ms correlation result is amplified by 20 times, resulting in a limited time impact. A comprehensive evaluation shows that the processing speed can be improved by nearly 20 times, while simultaneously achieving bit synchronization and locating the starting position of message bits.
[0067] A BDS B1I signal with a bit period of 20ms has a fixed sequence of NH codes modulated on each data bit. By finding the start edge of the data bit, the NH codes can be stripped, and the signal-to-noise ratio of the stripped signal can be improved by multi-millisecond coherent integration within each data bit period.
[0068] The acquisition process involves iterating through the Doppler and code phase of the target signal to find the Doppler and code phase that are closest to the true value of the signal. This rough result is then used for tracking, and the true signal is tracked through carrier loop and code loop.
[0069] Optionally, as another embodiment of the present invention, the present invention utilizes storage space to copy and store 20 copies of 1ms coherent integration results, each corresponding to a different processing NH phase start position. After NH code stripping is completed for each data, multi-millisecond coherent integration and incoherent integration are performed, and the final results are compared, with the maximum value point being taken as the capture result.
[0070] Compared with existing technologies, this invention does not perform cyclic NH code stripping on the sampled data, but instead performs NH code stripping on the result after 1ms coherent integration. Therefore, the number of times the matched filter is executed, which accounts for the highest proportion of time in the acquisition process, is reduced to 1 / 20 of the original, and the final processing time is also reduced to approximately 1 / 20. By improving the acquisition processing speed, the acquisition sensitivity of BeiDou signals is improved.
[0071] Alternatively, as another embodiment of the present invention, the specific steps of the present invention are as follows:
[0072] 1. Make 20 copies of the coherent integration result over 1 ms, corresponding to different positions of the NH code;
[0073] 2. For the 20 coherent integration results in 1ms, perform NH code stripping operation according to their respective NH code positions;
[0074] 3. After stripping the NH code, add the real and imaginary parts of the result to the cumulative result of the coherent integration, and increment the coherent integration count by 1;
[0075] 4. If the number of coherent integrations reaches the preset value N_coh, the amplitude of the complex data in the coherent integration accumulation result is taken and added to the incoherent accumulation result. The number of coherent integrations is cleared to zero, and the number of incoherent integrations is incremented by 1.
[0076] 5. Repeat steps 1 to 4, with the NH code shifted cyclically every 1ms, until the number of incoherent integrations reaches the threshold;
[0077] 6. Compare the data with different Doppler-code phases and initial NH positions, and take the maximum value as the capture result.
[0078] Figure 4 This is a block diagram of a satellite signal acquisition device provided in an embodiment of the present invention.
[0079] Alternatively, as another embodiment of the present invention, such as Figure 4 As shown, a satellite signal acquisition device includes:
[0080] The coherent integration result acquisition module is used to obtain the original coherent integration results of multiple initial NH code positions from any one of the multiple original Doppler code phase positions;
[0081] The import module is used to import NH codes;
[0082] The analysis module is used to analyze the non-coherent integration results of multiple original coherent integration results corresponding to the phase position of the original Doppler code based on the NH code, obtain the target non-coherent integration result, and return to the coherent integration result acquisition module until all the multiple original coherent integration results corresponding to the phase position of the original Doppler code have been analyzed, thereby obtaining the target non-coherent integration result corresponding to each phase position of the original Doppler code.
[0083] The acquisition result acquisition module is used to filter all the original coherent integration results and all the target incoherent integration results to select the satellite signal acquisition results.
[0084] Optionally, as an embodiment of the present invention, the analysis module imports NH codes and analyzes the incoherent integration results of multiple original coherent integration results corresponding to the phase positions of the original Doppler codes based on the NH codes to obtain the target incoherent integration result.
[0085] S21: Import the NH code, and perform NH code stripping processing on each original coherent integration result corresponding to the phase position of the original Doppler code according to the NH code, to obtain the stripped coherent integration result corresponding to each original coherent integration result.
[0086] S22: Sum all the stripped coherent integration results to obtain the coherent integration result to be processed, and return to S21 until the preset number of iterations is reached, thereby obtaining multiple coherent integration results to be processed;
[0087] S23: Summate all the coherent integral results to be processed to obtain the target incoherent integral result.
[0088] Optionally, as an embodiment of the present invention, the process of S23 includes:
[0089] Extract the coherent integral amplitude corresponding to each of the coherent integral results to be processed from each of the coherent integral results to be processed;
[0090] The target incoherent integral result is obtained by summing all the coherent integral amplitudes.
[0091] Optionally, as an embodiment of the present invention, the capture result acquisition module is specifically used for:
[0092] The maximum value among all the target incoherent integration results is selected, and the maximum target incoherent integration result is obtained. The original Doppler code phase position corresponding to the maximum target incoherent integration result is taken as the target Doppler code phase position.
[0093] The maximum value among all raw coherent integration results corresponding to the target Doppler code phase position is selected, and the maximum raw coherent integration result is obtained. The initial NH code position corresponding to the maximum raw coherent integration result is taken as the target NH code position, and the target Doppler code phase position and the target NH code position are taken as the satellite signal acquisition result.
[0094] Optionally, another embodiment of the present invention provides a satellite signal acquisition system, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the satellite signal acquisition method as described above. This system can be a computer or similar system.
[0095] Optionally, another embodiment of the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the satellite signal acquisition method as described above.
[0096] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
[0097] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the above-described apparatus and unit can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.
[0098] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed.
[0099] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments of the present invention, depending on actual needs.
[0100] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.
[0101] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.
[0102] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A satellite signal acquisition method, characterized in that, Includes the following steps: S1: Obtain the original coherent integral results of multiple initial NH code positions from any one of the multiple original Doppler code phase positions; S2: Import the NH code, analyze the incoherent integration results of multiple original coherent integration results corresponding to the phase position of the original Doppler code according to the NH code, obtain the target incoherent integration result, and return to S1, until all the multiple original coherent integration results corresponding to the phase position of the original Doppler code have been analyzed, thereby obtaining the target incoherent integration result corresponding to each phase position of the original Doppler code. S3: Filter all the original coherent integration results and all the target incoherent integration results to select the satellite signal acquisition results.
2. The satellite signal acquisition method according to claim 1, characterized in that, In step S2, the process of importing the NH code and analyzing the incoherent integration results of multiple original coherent integration results corresponding to the phase positions of the original Doppler code based on the NH code to obtain the target incoherent integration result includes: S21: Import the NH code, and perform NH code stripping processing on each original coherent integration result corresponding to the phase position of the original Doppler code according to the NH code, to obtain the stripped coherent integration result corresponding to each original coherent integration result. S22: Sum all the stripped coherent integration results to obtain the coherent integration result to be processed, and return to S21 until the preset number of iterations is reached, thereby obtaining multiple coherent integration results to be processed; S23: Summate all the coherent integral results to be processed to obtain the target incoherent integral result.
3. The satellite signal acquisition method according to claim 2, characterized in that, The process S23 includes: Extract the coherent integral amplitude corresponding to each of the coherent integral results to be processed from each of the coherent integral results to be processed; The target incoherent integral result is obtained by summing all the coherent integral amplitudes.
4. The satellite signal acquisition method according to claim 1, characterized in that, The process S3 includes: The maximum value among all the target incoherent integration results is selected, and the maximum target incoherent integration result is obtained. The original Doppler code phase position corresponding to the maximum target incoherent integration result is taken as the target Doppler code phase position. The maximum value among all raw coherent integration results corresponding to the target Doppler code phase position is selected, and the maximum raw coherent integration result is obtained. The initial NH code position corresponding to the maximum raw coherent integration result is taken as the target NH code position, and the target Doppler code phase position and the target NH code position are taken as the satellite signal acquisition result.
5. A satellite signal acquisition device, characterized in that, include: The coherent integration result acquisition module is used to obtain the original coherent integration results of multiple initial NH code positions from any one of the multiple original Doppler code phase positions; The import module is used to import NH codes; The analysis module is used to analyze the non-coherent integration results of multiple original coherent integration results corresponding to the phase position of the original Doppler code based on the NH code, obtain the target non-coherent integration result, and return to the coherent integration result acquisition module until all the multiple original coherent integration results corresponding to the phase position of the original Doppler code have been analyzed, thereby obtaining the target non-coherent integration result corresponding to each phase position of the original Doppler code. The acquisition result acquisition module is used to filter all the original coherent integration results and all the target incoherent integration results to select the satellite signal acquisition results.
6. The satellite signal acquisition device according to claim 5, characterized in that, The analysis module imports the NH code and analyzes the incoherent integration results of multiple original coherent integration results corresponding to the phase positions of the original Doppler code based on the NH code to obtain the target incoherent integration result. S21: Import the NH code, and perform NH code stripping processing on each original coherent integration result corresponding to the phase position of the original Doppler code according to the NH code, to obtain the stripped coherent integration result corresponding to each original coherent integration result. S22: Sum all the stripped coherent integration results to obtain the coherent integration result to be processed, and return to S21 until the preset number of iterations is reached, thereby obtaining multiple coherent integration results to be processed; S23: Summate all the coherent integral results to be processed to obtain the target incoherent integral result.
7. The satellite signal acquisition device according to claim 6, characterized in that, The process S23 includes: Extract the coherent integral amplitude corresponding to each of the coherent integral results to be processed from each of the coherent integral results to be processed; The target incoherent integral result is obtained by summing all the coherent integral amplitudes.
8. The satellite signal acquisition device according to claim 5, characterized in that, The capture result acquisition module is specifically used for: The maximum value among all the target incoherent integration results is selected, and the maximum target incoherent integration result is obtained. The original Doppler code phase position corresponding to the maximum target incoherent integration result is taken as the target Doppler code phase position. The maximum value among all raw coherent integration results corresponding to the target Doppler code phase position is selected, and the maximum raw coherent integration result is obtained. The initial NH code position corresponding to the maximum raw coherent integration result is taken as the target NH code position, and the target Doppler code phase position and the target NH code position are taken as the satellite signal acquisition result.
9. A satellite signal acquisition system, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the satellite signal acquisition method as described in any one of claims 1 to 4.
10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the satellite signal acquisition method as described in any one of claims 1 to 4.